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Home My WebLink About20232738.tiffUSE BY SPECIAL REVIEW (USR) APPLICATION FOR PLANNING DEPARTMENT USE: AMOUNT $ APPLICATION RECEIVED BY DATE RECEIVED: CASE # ASSIGNED: PLANNER ASSIGNED: P ROPERTY INFORMATION Is the property currently in violation? Parcel Number: 1 No/ 0 5 5 _ 1 4 Yes Violation Case Number: _ 3 _ 0 0 _ 0 3 0 S ite Address: Near 21566 CO RD 43, La Salle, CO 80645 Legal Description: A portion of PT SW4 14-4-65 LOT D REC EXEMPT RE -4420 Section: 14 , Township 4 Within subdivision or townsite? N, Range 65 No / Yes Name: W Zoning District: A Acreage: 152.2652 Water (well permit # or water district tap #): N/A Sewer (On -site wastewater treatment system permit # or sewer account #) N/A Floodplain No/ Yes Geological Hazard P ROJECT U SR Use being applied for: Solar Facilities Name of proposed business: CBEP Solar 26, LLC No/ Yes PROPERTY OWNER(S) (Attach additional sheets if necessary.) Name: Michael Boulter Airport Overlay No / ✓ Yes Company: Michael Boulter Farms, LLC Phone #: (701) 770-1238 Email: ncesmadtat53@msn.com Street Address: 22019 County Road 54 City/State/Zip Code: Greeley, CO 80631 APPLICANT/AUTHORIZED AGENT (Authorization Form must be included if there is an Authorized Agent) Name: Zach Brammer Company: CBEP Solar 26, LLC Phone #: (970) 425-3175 Email: zach@cloudbreakenergy.com Street Address: PO Box 1255 City/State/Zip Code: Sterling, CO 80751 I (We) hereby depose and state under penalties of perjury that all statements, proposals, and/or plans submitted with or contained within the application are true and correct to the best of my (our) knowledge. All fee owners of the property must sign this application. If an Authorized Agent signs, an Authorization Form signed by all fee owners must be included with the application. If the fee owner is a corporation, evidence must be included indicating the signatory has the legal authority to sign for the corporation. 04/24/2023 ignatLte Date Zachary Brammer Signature Date Print Print Document must be filed electronically. Paper documents are not accepted. Fees & forms are subject to change. For more information or to print copies of filed documents, visit www.sos.state.co.us. Colorado Secretary of State Date and Time: 01/16/2015 10:44 AM ID Number: 20151032494 Document number: 20151032494 Amount Paid: $50.00 ABOVE SPACE FOR OFFICE USE ONLY Articles of Organization filed pursuant to § 7-80-203 and § 7-80-204 of the Colorado Revised Statutes (C.R.S.) 1. The domestic entity name of the limited liability company is Michael Boulter Farms, LLC (The name of a limited liability company must contain the term or abbreviation "limited liability company", "ltd. liability company", "limited liability co. ", "ltd. liability co.", "limited", "1.1.c.", "llc", or "ltd.". See §7-90-601, C.R.S.) (Caution: The use of certain terms or abbreviations are restricted by law. Read instructions for more information.) 2. The principal office address of the limited liability company's initial principal office is Street address Mailing address 22019 County Road 54 (Street number and name) Greeley (City) CO 80631 (State) (ZIP/Postal Code) United States (Province — if applicable) (Country) (leave blank if same as street address) (Street number and name or Post Office Box information) (City) (State) (ZIP/Postal Code) (Province — if applicable) (Country) 3. The registered agent name and registered agent address of the limited liability company's initial registered agent are Name (if an individual) or (if an entity) Boulter Michael J (Last) (First) (Middle) (Suffix) (Caution: Do not provide both an individual and an entity name.) Street address Mailing address (leave blank if same as street address) (Street number and name or Post Office Box information) 22019 County Road 54 (Street number and name) Greeley (City) CO 80631 (State) (ZIP Code) ARTORG LLC Page 1 of 3 Rev. 12/01/2012 Co (The following statement is adopted by marking the box.) The person appointed as registered agent has consented to being so appointed. (City) (State) (ZIP Code) 4. The true name and mailing address of the person forming the limited liability company are Name (if an individual) or (if an entity) Boulter Michael J (Last) (First) (Middle) (Suffix) (Caution: Do not provide both an individual and an entity name.) Mailing address 22019 County Road 54 (Street number and name or Post Office Box information) Greeley CO 80631 (City) (State) (ZIP/Postal Code) United States (Province — if applicable) (County y) (If the following statement applies, adopt the statement by marking the box and include an attachment.) The limited liability company has one or more additional persons forming the limited liability company and the name and mailing address of each such person are stated in an attachment. 5. The management of the limited liability company is vested in (Mark the applicable box.) one or more managers. or the members. 6. (The following statement is adopted by marking the box.) There is at least one member of the limited liability company. 7. (If the following statement applies, adopt the statement by marking the box and include an attachment.) This document contains additional information as provided by law. 8. (Caution: Leave blank if the document does not have a delayed effective date. Stating a delayed effective date has significant legal consequences. Read instructions before entering a date.) (If the following statement applies, adopt the statement by entering a date and, if applicable, time using the required format.) The delayed effective date and, if applicable, time of this document is/are (mm/dd/yyyy hour: minute am/pm) Notice: Causing this document to be delivered to the Secretary of State for filing shall constitute the affirmation or acknowledgment of each individual causing such delivery, under penalties of perjury, that the document is the individual's act and deed, or that the individual in good faith believes the document is the act and deed of the person on whose behalf the individual is causing the document to be delivered for filing, taken in conformity with the requirements of part 3 of article 90 of title 7, C.R.S., the constituent documents, and the organic statutes, and that the individual in good faith believes the facts stated in the document are true and the document complies with the requirements of that Part, the constituent documents, and the organic statutes. ARTORG LLC Page 2 of 3 Rev. 12/01/2012 This perjury notice applies to each individual who causes this document to be delivered to the Secretary of State, whether or not such individual is named in the document as one who has caused it to be delivered. 9. The true name and mailing address of the individual causing the document to be delivered for filing are Penny Robert J (Last) 323 So. College Ave., #3 (First) (Middle) (Suffix) (Street number and name or Post Office Box information) Fort Collins (City) CO 80524 (State) (ZIP/Postal. Code) United States (Province — if applicable) (Country) (If the following statement applies, adopt the statement by marking the box and include an attachment.) This document contains the true name and mailing address of one or more additional individuals causing the document to be delivered for filing. Disclaimer: This form/cover sheet, and any related instructions, are not intended to provide legal, business or tax advice, and are furnished without representation or warranty. While this form/cover sheet is believed to satisfy minimum legal requirements as of its revision date, compliance with applicable law, as the same may be amended from time to time, remains the responsibility of the user of this form/cover sheet. Questions should be addressed to the user's legal, business or tax advisor(s). ARTORG LLC Page 3 of 3 Rev. 12/01/2012 Weld County Drainage Code Certificate of Compliance Weld County Case Number: Parcel Number: Legal Description, Section/Township/Range: Date: , Consultant Engineer for (Applicant), understand and acknowledge that the applicant is seeking land use approval of the case and parcel in the description above. I have designed or reviewed the design for the proposed land use set for in the application. I hereby certify, on behalf of the applicant, that the design will meet all applicable drainage requirements of the Weld County Code with the exception of the variances) described on the attached exhibits. This certification is not a guarantee or warranty either expressed or implied. Engineer's Stamp: Engineer of Record Signature Variance Request (If Applicable) 1. Describe the hardship for which the variance is being requested. 2. List the design criteria of the Weld County Code of which a variance is being requested. 3. Describe the proposed alternative with engineering rationale which supports the intent of the Weld County Code. Demonstrate that granting of the variance will still adequately protect public health, safety, and general welfare and that there are no adverse impacts from stormwater runoff to the public rights -of -way and/or offsite properties as a result of the project. Public Works Director/Designee Review (If Applicable) Public Works Director/Designee Name Date of Signature Comments: Signature Approved ❑ Denied Department of Public Works Development Review 1111 H Street, Greeley, Co 80631 I Ph: 970-304-6496 www.weldgov.com/departments/public_works/development_ review 08/02/2019 Document must be filed electronically. Paper documents are not accepted. Fees & forms are subject to change. For more information or to print copies of filed documents, visit www.coloradosos.gov. Colorado Secretary of State Date and Time: 02/24/2023 04:23 PM ID Number: 202312203 98 Document number: 202312203 98 Amount Paid: $100.00 ABOVE SPACE FOR OFFICE USE ONLY Statement of Foreign Entity Authority filed pursuant to § 7-90-803 of the Colorado Revised Statutes (C.R.S.) 1. The entity ID number, the entity name, and the true name, if different, are Entity ID number 20231220398 (Colorado Secretary ofState ID number) Entity name CBEP Solar 26, LLC True name (if different from the entity name) 2. The form of entity and the jurisdiction under the law of which the entity is formed are Form of entity Foreign Limited Liability Company Jurisdiction Delaware 3. The principal office address of the entity's principal office is Street address Mailing address (leave blank if same as street address) 4845 Pearl East Cir (Street number and name) Suite 118 #53242 Boulder (City) (Province — if applicable) CO 80301 (State) (ZIP/Postal Code) United States (Como)) (Street number and name or Post Office Box information) (City) (Province — if applicable) (State) (ZIP/Postal Code) (Country) 4. The registered agent name and registered agent address of the entity's registered agent are Name (if an individual) or (if an entity) Cloudbreak Energy Partners, LLC (Last) (Caution: Do not provide both an individual and an entity name.) (First) (Middle) (Suffix) AUTHORITY Page 1 of 3 Rev. 12/01/2011 Street address 4845 Pearl East Cir (Street number and name) Suite 118 #53242 Mailing address Boulder CO 80301 (City) (State) (ZIP Code) (leave blank if same as street address) (Street number and name or Post Office Box information) (The following statement is adopted by marking the box.) VA (City) CO (State) (ZIP Code) The person appointed as registered agent above has consented to being so appointed. 5. The date the entity commenced or expects to commence transacting business or conducting activities in Colorado is 02/27/2023 (mm/dd/yyyy) 6. (If applicable, adopt the following statement by marking the box and include an attachment) ❑ This document contains additional information as provided by law. 7. (Caution: Leave blank if the document does not have a delayed effective date. Stating a delayed effective date has sign f cant legal consequences. Read instructions before entering a date.) (If the following statement applies, adopt the statement by entering a date and, if applicable, time using the required format) The delayed effective date and, if applicable, time of this document is/are (mm/dd/yyyy hour:minute am/pm) Notice: Causing this document to be delivered to the Secretary of State for filing shall constitute the affirmation or acknowledgment of each individual causing such delivery, under penalties of perjury, that the document is the individual's act and deed, or that the individual in good faith believes the document is the act and deed of the person on whose behalf the individual is causing the document to be delivered for filing, taken in conformity with the requirements of part 3 of article 90 of title 7, C.R.S., the constituent documents, and the organic statutes, and that the individual in good faith believes the facts stated in the document are true and the document complies with the requirements of that Part, the constituent documents, and the organic statutes. This perjury notice applies to each individual who causes this document to be delivered to the Secretary of State, whether or not such individual is named in the document as one who has caused it to be delivered. 8. The true name and mailing address of the individual causing the document to be delivered for filing are Tupper Karin (Last) (First) Moye White LLP (Middle) (Suffix) (Street number and name or Post. Office Box information) 1400 16th Street, 6th Floor Denver (City) CO 80202 (State) (ZIP/Postal Code) United States . (Province — if applicable) (Country) (If the following statement applies, adopt the statement by marking the box and include an attachment.) This document contains the true name and mailing address of one or more additional individuals causing the document to be delivered for filing. AUTHORITY Page 2 of 3 Rev. 12/01/2011 Disclaimer: This form/cover sheet, and any related instructions, are not intended to provide legal, business or tax advice, and are furnished without representation or warranty. While this form/cover sheet is believed to satisfy minimum legal requirements as of its revision date, compliance with applicable law, as the same may be amended from time to time, remains the responsibility of the user of this form/cover sheet. Questions should be addressed to the user's legal, business or tax advisor(s). AUTHORITY Page 3 of 3 Rev. 12/01/2011 CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Planning Questionnaire 1. Explain the proposed use and business name: o CBEP Solar 26, LLC is proposing to construct and operate the Blue Spruce Solar Project ("Project") in unincorporated Weld County on Parcel ID number 105514300030. The Project will be a 10 MWac community solar garden and will be constructed on approximately 66.52 acres of privately owned land. It will consist of solar modules mounted about 5 feet above the existing grade on single -axis trackers, which allow the panels to track the sun from east to west over the course of the day. The project will also include inverters mounted on steel posts or beams, concrete -pad mounted transformers, other electrical equipment, an access road, and a perimeter game fence with gates. 2. Explain the need for the proposed use: o Ensuring long-term energy security for the United States requires a mixture of all different types of energy production, including community solar projects like the Blue Spruce Solar Project. 3. Describe the current and previous use of the land. o The land is currently vacant (no existing water rights to be used for crop production) and has historically been used for oil and gas production. 4. Describe the proximity of the proposed use to residences. o The nearest residence is approximately 240 feet to the west of the Project's fenceline. 5. Describe the surrounding land uses of the site and how the proposed use is compatible with them. o The surrounding land use includes residential, oil and gas production, and agricultural land use. 6. Describe the hours and days of operation (i.e. Monday thru Friday 8:00 a.m. to 5:00 (970) 425-3175 I INFO©aCLOUDBREAKENERGY.COM I CLOUDBREAKENERGY.COM CLOUDBREAK PAGE2 o Construction activities will take place Monday through Saturday from 7:00 a.m. to 6:00 p.m. After construction is completed, occasional maintenance will occur between 7:00 a.m. and 7:00 p.m. as needed. 7. Describe the number of employees including full-time, part-time and contractors. If shift work is proposed,, detail number of employees, schedule and duration of shifts. o Construction may require up to 50 workers to be on site at one time during the peak of construction, all contractors during the day shift. Construction employees may include up to 15 civil workers, 15 electricians, 15 racking builders, and an additional 5 employees. During operations, two to four employees may be needed for maintenance, as needed, approximately twice a year. 8. Describe the maximum number of users, patrons, members, buyers or other visitors that the site will accommodate at any one time. o No users, patrons, members, buyers, or other visitors are expected to be on the site at any time. 9. List the types and maximum numbers of animals to be on the site at any one time (for dairies, livestock confinement operations, kennels, etc.). o Up to 500 sheep. 10. List the types and number of operating and processing equipment. o The Project will consist of approximately 24,544 solar modules mounted about 5 feet above the existing grade on single -axis trackers, which allow the panels to track the sun from east to west over the course of the day. The project will also include 100 inverters mounted on steel posts or beams, 4 concrete pad mounted transformers, and other electrical equipment. 11. List the types, number and uses of the existing and proposed structures. o There are no existing structures on the Project's site. o The proposed structures for the Project will include: I. Approximately 24,544 solar modules mounted about 5 feet above the existing grade on single -axis trackers, which allow the panels to track the sun from east to west over the course of the day. ii. 100 inverters mounted on steel posts or beams iii. 4 concrete pad mounted transformers iv. Approximately 5 utility poles that will connect the project to the existing Xcel Energy distribution line on the west side of the property. v. One temporary construction trailer vi. Two 10' x 40' storage containers that will store parts, tools, and equipment on site during construction and operations (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKEICIEPGY.COM CLOUDBREAK PAGE 3 12. Describe the size of any stockpile, storage or waste areas. o During construction, a laydown area located within the limits of the Project area will be used to store Project facility items while facilities are installed. During operations, there will be no open stockpiling, uncovered storage, or waste areas. Up to two storage containers approximately 40 -feet in length, 10 feet in width, and 10 feet in height to store spare parts, tools, and equipment on site during construction and operations. 13. Describe the method and time schedule of removal or disposal of debris, junk and other wastes associated with the proposed use. o Debris, junk, and other wastes will be stored in appropriate waste receptacles such as dumpsters during construction. CBEP Solar 26, LLC or its contractors will hire a waste management provider to regularly remove wastes associated with construction of the Project from the receptacles and bring the waste to an approved landfill or disposal site. Maintenance contractors will properly dispose of any wastes generated during operation of the Project by bringing the wastes to an approved landfill or disposal site. 14. Include a timetable showing the periods of time required for the construction of the operation. o Project construction is expected to begin in Q1 2024 and is expected to be completed in Q2 2024. Construction activities would follow the estimated timetable below: Construction Phase Season/Duration Construction Begins O1 2024 Site preparation 1-2 months Structural work 3-5 months Electrical work 2-4 months Utility work 2-4 months Construction Completion Q2 2024 15. Describe the proposed and existing lot surface type and the square footage of each type (i.e. asphalt, gravel, landscaping, dirt, grass, buildings). o The existing lot surface type is all vegetated land. The proposed surface types and square footage of each type are listed below: i. Concrete: 9,619 sq ft (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGE4- ii. Gravel: 73,786 sq ft iii. Swales: 0 sq ft iv. Grass/Vacant: 3,511,765 sq ft v. Solar Racking: 623,949 sq ft 16. How many parking spaces are proposed? How many handicap -accessible parking spaces are proposed? o No parking spaces or handicap -accessible parking spaces are proposed. 17. Describe the existing and proposed fencing and screening for the site including all parking and outdoor storage areas. o There is no existing fencing or screening on the site. The Project will be surrounded by a game fence that is at least 7 feet tall. 18. Describe the existing and proposed landscaping for the site. o There is no existing landscaping on the site and there is no proposed landscaping. 19. Describe reclamation procedures to be employed as stages of the operation are phased out or upon cessation of the Use by Special Review activity. o Decommissioning of the Project will commence within 12 months after power production has permanently ceased and be completed within 12 months of the decommissioning work commencing. Decommissioning will include the removal of: i. All non -utility owned equipment, conduits, structures, fencing, and foundations to a depth of at least three (3) feet below grade ii. All fences, graveled areas and access roads unless the property owner agrees for this to remain o The property will be restored to a condition reasonably similar to its condition prior to the development of the Project 20. Describe the proposed fire protection measures. o The Project is located within the La Salle Fire Protection District. The Project will comply with all Colorado Public Utilities Commission requirements as well as national codes and standards for construction, electrical, and fire. A supervisory control and data acquisition (SCADA) system will remotely monitor and control the Project 24 hours per day. The SCADA system will transmit Project data and control signals over the internet. 21. Explain how this proposal is consistent with the Weld County Comprehensive Plan per Chapter 22 of the Weld County Code. o The Project is consistent with the Weld County Comprehensive Plan because it: (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGES i. Does not interfere with any existing agricultural operations within the vicinity. ii. Respects private property rights by allowing the owner of the property to do what is in their best interest while complying with local regulations and not interfering with or infringing upon the rights of others. iii. Promotes economic growth and stability by providing a diversified source of income for the landowner, the shepherd, and the County while also offering local residents the opportunity to save money on their electricity bills through Xcel's Solar*Rewards Community Program. iv. Protects the health, safety, and general welfare of the citizens of the County by providing an emission -free source of energy. v. Is harmonious with surrounding agricultural and industrial uses. vi. Supports future mineral development by reserving space on the landowner's property where minerals can be extracted in the future. 22. Explain how this proposal is consistent with the intent of the zone district in which it is located. (Intent statements can be found at the be inning of each zone district section in Article III of Chapter 23 of the Weld County Code.) o The new solar development will not interfere with any of the surrounding agricultural land uses. The Project's array will protect the land underneath and in turn allow the soil to revitalize over time, therefore preserving the land to be u sed for agricultural purposes in the future, if desired. We will be planting a n ative seed mixture on the property that will not require irrigation. 23. Explain how this proposal will be compatible with future development of the surrounding area or adopted master plans of affected municipalities. o The Project will be located within any Intergovernmental Agreement area. 24. Explain how this proposal impacts the protection of the health, safety and welfare of the inhabitants of the neighborhood and the County. o The Project is not anticipated to impact the health, safety, and welfare of Weld County citizens. Designs will comply with Colorado Public Utilities Commission requirements as well as national codes and standards for construction, electrical, and fire. A supervisory control and data acquisition (SCADA) system will (970) 425-3175 I I N FO©a CLOU DBPEAKEN EPGY.COM I CLOU DBPEAKEN EPGY.COM CLOUDBREAK PAGE 6 remotely monitor and control the Project 24 hours per day. The SCADA system will transmit Project data and control signals over the internet. 25. Describe any irrigation features. If the proposed use is to be located in the A (Agricultural) Zone District, explain your efforts to conserve prime agricultural land in the locational decision for the proposed use. a We will be planting a native seed mixture on the property and grazing sheep to maintain the vegetation at a height of no more than 18-22 inches. The parcel currently has water rights which the landowner will be using on the agricultural land that the array is not covering. The landowner will use the water rights to support their remaining agricultural land, the sheep grazing underneath the array, and the native seed mixture. 26. Explain how this proposal complies with Article V and Article XI of Chapter 23 if the proposal is located within any Overlay Zoning District (Airport, Geologic Hazard, or Historic Townsites Overlay Districts) or a Special Flood Hazard Area identified by maps officially adopted by the County. o Flood Hazard, Geologic Hazard, and Historic Townsites: The Project is not located within the 1% Annual Chance Flood Hazard Area (Flood Zone A). According to the Colorado Geological Survey, no geologic hazards were identified within the Project Area. The Weld County property portal's Historic Townsite layer showed no presence of historic sites within the Project Area. o Airport: The Project is located within the Airport Overlay District. This District has unique height limitations as well as unique use restrictions. The use restrictions in Section 23-5-40 of the Weld County Code are defined as follows: "Notwithstanding any other provisions of this Division, no USE may be made of land or water within any zone established by this Division in such a manner as to create electrical interference with navigational signals or radio communication between the GREELEY-WELD COUNTY AIRPORT and aircraft, make it difficult for pilots to distinguish between GREELEY-WELD COUNTY AIRPORT lights and others, result in glare in the eyes of pilots using the GREELEY-WELD COUNTY AIRPORT, impair visibility in the vicinity of the GREELEY-WELD COUNTY AIRPORT, create bird strike hazards or otherwise in any way endanger or interfere with the landing, takeoff or maneuvering of aircraft intending to use the GREELEY-WELD COUNTY AIRPORT." As detailed below, the Project complies with these use restrictions as well as the height limitations: i. Electrical Interference - According to "Electro-Magnetic Interference from Solar Photovoltaic Arrays" published by the U.S. Department of the Navy, "The Federal Aviation Admiration (FAA) has indicated that EMI from PV installations is low risk. PV systems equipment such as step-up transformers and electrical cables are not sources of electromagnetic interference because of their (970) 425-3175 I I N FO©a CLOU DBPEAKEN EPGY.COM I CLOU DBPEAKEN EPGY.COM CLOUDBREAK PAGE7 low -frequency (60 Hz) of operation and PV panels themselves do not emit EMI. The only component of a PV array that may be capable of emitting EMI is the inverter. Inverters, however, produce extremely low frequency EMI similar to electrical appliances and at a distance of 150 feet from the inverters the EM field is at or below background levels." ii. Lights - The Project will not include any lighting, therefore there will be no effect in distinguishing Greeley -Weld County Airport lights and others. iii. Glare - CBEP Solar 2, LLC performed a glare analysis for the Project which is included within the application package. The Project will follow all FAA regulations and utilize mitigation measures proposed by the study. iv. Visibility - The Project will not impair visibility. v. Bird Strikes and Other Hazards: The Project will not create bird strike hazards or otherwise in any way endanger or interfere with the landing, takeoff or maneuvering of aircraft intending to use the Greeley -Weld County Airport. There will be no lights on the array nor anything else that would attract birds to the project area. vi. Height Limitations: Upon review of the Greeley -Weld County Airport Master Plan's Airport Layout Plan drawings, the parcel containing the Project Area was identified as a part of the Transitional Zone as well as the Horizontal Zone. The Project abides by the Airport Zone height limitations of both the Transitional Zone and the Horizontal Zone outlined in Sec. 25-5-30. 27. Detail known State or Federal permits required for your proposed use(s) and the status of each permit. Provide a copy of any application or permit. o There are no Federal permits required for the Project. o There are two State permits that may be required - the Colorado Department of Public Health and Environment Construction Stormwater Discharge Permit and the Colorado Department of Public Health and Environment Air Permit. No applications for State permits have been submitted. (970) 425-3175 I I N FO©a CLOU DBPEAKEN EPGY.COM I CLOU DBPEAKEN EPGY.COM CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Development Review Questionnaire 1. Describe the access location and applicable use types (i.e., agricultural, residential, commercial/industrial, and/or oil and gas) of all existing and proposed accesses to the parcel. Include the approximate distance each access is (or will be if proposed) from an intersecting county road. State that no existing access is present or that no new access is proposed, if applicable: o The Project parcel has 3 existing accesses and 1 proposed access. - Access 1, the proposed access for the Blue Spruce 2 Solar Project, is an existing access located on the southern side of the parcel on County Road 44, approximately 2,230 feet to the east of County Road 45 and 3,035 feet to the west of County Road 47. This access will be for the Project access. Access 2 is located on the southern side of the parcel on County Road 44, approximately 1,475 feet to the east of County Road 45 and 3,595 feet to the west of County Road 47. This is an existing Agricultural and Oil and Gas access. - Access 3 is located on the western side of the parcel on County Road 45, approximately 4,230 feet to the south of County Road 46 and 820 feet to the north of County Road 44.This is an existing Agricultural and Oil and Gas access. Access 4 is located on the western side of the parcel on County Road 45, approximately 3,530 feet to the south of County Road 46 and 1,740 feet to the north of County Road 44.This is an existing Agricultural and Oil and Gas access. 2. Describe any anticipated change(s) to an existing access, if applicable: o No accesses will be relocated. The Project access will be improved to serve as the Project access. 3. Describe in detail any existing or proposed access gate including its location: o There will be a 7 foot tall perimeter fence around the Project. The access gate will be loacted on the EASTern side of the Project area. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE 2 4. Describe the location of all existing accesses on adjacent parcels and on parcels located on the opposite side of the road. Include the approximate distance each access is from an intersecting county road: a There are 8 parcels adjacent to the Project parcel. o The parcel to the north of the Project parcel has 4 accesses. - Access 1 is located on the west side of the parcel on County Road 45 approximately 2,585 feet to the south of County Road 46 and 2,635 feet to the north of County Road 44. - Access 2 is located on the west side of the parcel on County Road 45 approximately 2,140 feet to the south of County Road 46 and 3,115 feet to the north of County Road 44. - Access 3 is located on the north side of the parcel on County Road 46, approximately 4,970 feet to the west of County Road 47 and 180 feet to the east of County Road 45. - Access 4 is located on the north side of the parcel on County Road 46, approximately 2,960 feet to the west of County Road 47 and 2,175 feet to the east of County Road 45. o There are 4 parcels to the east of the Project parcel. Below, these parcels are numbered eastern parcel 1-4, from the northernmost to the southernmost. Eastern parcel 1 has 3 accesses. - Access 1 is located on the east side of the parcel on County Road 47 approximately 2,690 feet to the south of County Road 46 and 2,585 feet to the north of County Road 44. - Access 2 is located on the south side of the parcel on County Road 44, approximately 670 feet to the west of County Road 47 and 4,520 feet to the east of County Road 45. - Access 3 is located on the south side of the parcel on County Road 44, approximately 1,970 feet to the west of County Road 47 and 3,325 feet to the east of County Road 45. a Eastern parcel 2 has no access. a Eastern parcel 3 has no access. a Eastern parcel 4 has 1 access located on the southern side of the parcel on County Road 44, approximately 2,380 feet to the east of County Road 45 and 2,830 feet to the west of County Road 47. a There is 1 parcel across County Road 44 to the south of the Project parcel. This parcel has 3 accesses. (970) 425-3175 I I N FO©a CLOU DBPEAKEN EPGY.COM I CLOU DBPEAKEN EPGY.COM CLOUDBREAK PAGE 3 - Access 1 is located on the north side of the parcel on County Road 44, approximately 2,625 feet to the west of County Road 47 and 2,580 feet to the east of County Road 45. - Access 2 is located on the north side of the parcel on County Road 44, approximately 3,367 feet to the west of County Road 47 and 1,860 feet to the east of County Road 45. - Access 3 is located on the north side of the parcel on County Road 44, approximately 5,140 feet to the west of County Road 47 and 60 feet to the east of County Road 45. o There are 2 parcels across County Road 45 to the west of the Project parcel, a large agricultural parcel and a small residential parcel. The agricultural parcel across County Road 45 to the west of the Project parcel has 3 accesses. - Access 1 is located on the south side of the parcel on County Road 44, approximately 35 feet to the west of County Road 45 and 5,050 feet to the east of County Road 43. - Access 2 is located on the south side of the parcel on County Road 44, approximately 645 feet to the west of County Road 45 and 4,570 feet to the east of County Road 43. - Access 3 is located on the east side of the parcel on County Road 45, approximately 2,510 feet to the north of County Road 44 and 2,760 feet to the south of County Road 46. o The residential parcel across County Road 45 to the west of the Project parcel has 3 accesses. - Access 1 is located on the east side of the parcel on County Road 45, approximately 1,405 feet to the north of County Road 44 and 3,850 feet to the south of County Road 46. - Access 2 is located on the east side of the parcel on County Road 45, approximately 1,605 feet to the north of County Road 44 and 3,665 feet to the south of County Road 46. - Access 3 is located on the east side of the parcel on County Road 45, approximately 1,665 feet to the north of County Road 44 and 3,610 feet to the south of County Road 46. 5. Describe any difficulties seeing oncoming traffic from an existing access and any anticipated difficulties seeing oncoming traffic from a proposed access: o The existing access should not have any difficulties seeing oncoming traffic. 6. Describe any horizontal curve (using terms like mild curve, sharp curve, reverse curve, etc.) in the vicinity of an existing or proposed access: (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGE 4 a The existing access does not have any horizontal curves in the vicinity. 7. Describe the topography (using terms like flat, slight hills, steep hills, etc.) of the road in the vicinity of an existing or proposed access: a The topography of the road in the vicinity of the existing access is flat. (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Environmental Health Questionnaire 1. Discuss the existing and proposed potable water source. If utilizing a drinking water well, include either the well permit or well permit application that was submitted to the State Division of Water Resources. If utilizing a public water tap, include a letter from the Water District, a tap or meter number, or a copy of the water bill.: o The Project area does not have an existing potable water source. There is no proposed potable water source for the Project. Bottled water will be provided for the construction team. Any water used for dust mitigation will be brought to the property from an external source. 2. Discuss the existing and proposed sewage disposal system. What type of sewage disposal system is on the property? If utilizing an existing on -site wastewater treatment system, provide the on -site wastewater treatment permit number. (If there is no on -site wastewater treatment permit due to the age of the existing on -site wastewater treatment system, apply for a on -site wastewater treatment permit through the Department of Public Health and Environment prior to submitting this application.) If a new on -site wastewater treatment system will be installed, please state "a new on -site wastewater treatment system is proposed." (Only propose portable toilets if the use is consistent with the Department of Public Health and Environment's portable toilet p olicy.) o There is no existing on -site sewage disposal system. The operation of the Project is not anticipated to require a sewage disposal system. CBEP Solar 26, LLC or its contractors will provide portable toilets during construction. 3. If storage or warehousing is proposed, what type of items will be stored: o The Project will include up to two 10' x 40' storage containers that will store parts, tools, and equipment on site during construction and operations. 4. Describe where and how storage and/or stockpile of wastes, chemicals, and/or petroleum will occur on this site: o During construction wastes will be stored in appropriate waste receptacles such as dumpsters. CBEP Solar 26, LLC and its contractors will hire a waste management provider to regularly remove wastes associated with construction of the Project from the receptacles and bring the waste to an approved landfill (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE2 or disposal site. Maintenance contractors will properly dispose of any wastes generated during operation of the Project by bringing the wastes to an approved landfill or disposal site. During construction, up to 1,000 gallons of fuel will be stored on -site in appropriate containers. No fuel will be stored on site for operations. No other chemicals are anticipated to be stored during construction or operation of the Project. 5. If there will be fuel storage on site, indicate the gallons and the secondary containment. State the number of tanks and gallons per tank: o Up to 1,000 gallons of fuel are anticipated to be stored on one site at one time during construction. Storage of fuel will follow applicable secondary containment requirements, as applicable. There will not be fuel storage during operation of the Project. 6. If there will be washing of vehicles or equipment on site, indicate how the wash water will be contained: o There will not be vehicle washing/equipment on site during the construction and operation of the Project. 7. If there will be floor drains, indicate how the fluids will be contained: o None of the facilities constructed for the Project will contain floor drains or require wastewater treatment. 8. Indicate if there will be any air emissions (e.g. painting, oil storage, etc.): o Traffic volume, primarily in the form of passenger vehicles, would increase in and around the Project area during construction. The increased traffic would temporarily increase odors and exhaust from vehicle emissions. Odors are anticipated from the operation of heavy machinery during grading, pile driving, and other installation activities at specific time periods throughout construction. Impacts from odors during Project operation would be minimal, likely restricted to emissions from the vehicles of maintenance personnel. 9. Provide a design and operations plan if applicable (e.g. composting, landfills, etc.): o A design and operations plan is not applicable to the Project. 10. Provide a nuisance management plan if applicable (e.g. dairies, feedlots, etc.): o A nuisance management plan is not applicable to the Project. 11. Additional information may be requested depending on type of land use requested: o If any additional information is required, please don't hesitate to contact Zach Brammeratzach@cloudbreakenergy.com- (970) 425-3175. (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM FOR COMMERCIAL OR INDUSTRIAL BUILDINGS, PLEASE COMPLETE THE FOLLOWING INFORMATION: Business Name: Address: Business Owner: Home Address: CBEP Solar 26, LLC PO Box 1255 Cloudbreak Energy Partners, LLC PO Box 1255 Phone: City, state, zip: Phone: City, state, zip: List up to three persons in the order to be called in the event of an emergency: NAME Zachary Brammer TITLE COO PHONE (970) 425-3175 (970) 425-3175 Sterling, CO 80751 (970) 425-3175 Sterling, CO 80751 ADDRESS PO Box 1255, Sterling, CO 80751 Becca Gallery Partner (970) 573-6440 PO Box 1255, Sterling, CO 80751 James Cleland CEO (970) 425-3175 PO Box 1255, Sterling, CO 80751 Business Hours: 8-5 UTILITY SHUT OFF LOCATIONS: Main Electrical: Gas Shut Off: Depicted on USR Map Days: M -F N/A Exterior Water Shutoff: N/A Interior Water Shutoff: N/A 07/22 12 4878921 01/27/2023 09:25 AM Total Pages: 4 Rec Fee: $28.00 Carly Koppes - Clerk and Recorder, Weld County , CO MEMORANDUM OF LEASE AND EASEMENT OPTION AGREEMENT THIS MEMORANDUM OF LEASE AND EASEMENT OPTION AGREEMENT ("Memorandum") is entered into as of December 29, 2022 by and between Michael Boulter Farms, LLC, a Colorado limited liability company ("Owner"), and Cloudbreak. Energy Partners, LLC, a Delaware limited liability company, and its successors and assigns ("Operator"). RECITALS A. Owner and Operator have entered into that certain Lease and Easement Option Agreement (the "Lease Agreement"), dated December 29, 2022 (the "Effective Date"), whereby Owner has granted Operator the right to conduct due diligence on the Owner's Property and an option to lease and develop a portion of the Owner's Property (the "Option"), together with easement rights on, over, under, across, and through said Owner's Property, in the County of Weld, State of Colorado , and being more particularly described in Schedule A attached hereto and made a part hereof (the "Owner's Property"). B. This Memorandum is being executed and recorded to evidence the Lease Agreement and shall not be construed to limit, amend or modify the provisions of the Lease Agreement in any respect. MEMORANDUM 1. OTW1ER. The name of the Owner is Michael Boulter Farms, LLC, a Colorado limited liability company with an address of 22019 County Road 54, Greeley, CO 80631. 2. OPERATOR. The name of the Operator is Cloudbreak Energy Partners, LLC, a Delaware limited liability company, having an address of 4845 Pearl East Circle, Suite 118 #53242, Boulder, Colorado 80301, and its successors and assigns. 3. LEGAL DESCRIPTION. The specific legal description of the Owner's Property is described on Schedule A and is incorporated herein by this reference. 4. OPTION TERM. Owner has granted Operator the right to conduct due diligence on the Owner's Property to determine if the Operator would like to enter into a lease. The initial term of the Option Agreement is a period which commenced on December 29, 2022 and ends on December 29, 2025. The term of the Option may be extended, at Operator's discretion, for one (1) calendar year, as provided in the Lease Agreement. 5. LEASE TERM. In the event the Option is exercised under the Lease Agreement, the term of the lease will commence on the Commencement Date (as defined in the Lease Agreement) and shall expire on the twentieth (20th) anniversary of the Commercial Operation Date (as defined in the Lease Agreement). 48 Error! Unknown document property name. 4878921 01/27/2023 09:25 AM Page 2 of 4 7i1Or 6. EXTENTION TERMS. Operator has the option to extend the term of the lease for three (3) additional extension terms of five (5) years each on the terms and conditions more particularly set forth in the Lease Agreement. 7. EASEMENTS. In connection with the Lease Agreement, Owner has granted or has agreed to grant Operator a number of easements on, over, under, across and through Owner's Property, which are fully described in the Lease Agreement. 8. OTHER TERMS. In addition to those terms referenced herein, the Lease Agreement contains numerous other terms, covenants and conditions, and notice is hereby given that reference should be made to the Lease Agreement directly with respect to the details of such terms, covenants, and conditions. In the event of a conflict between the provisions of this instrument and the Lease Agreement, the provisions of the Lease Agreement shall control. 9. AGREEMENT TO COOPERATE. At the request of Owner after expiration of the termination of the Lease Agreement, Operator shall reasonably cooperate with Owner in all respects with obtaining the removal of the Memorandum from title, including without limitation executing a termination of Memorandum in form reasonably required by Owner. IN WITNESS WHEREOF, the undersigned have caused this instrument to be executed as of the date first written above. OWNER Michael Boulter Farms, LLC a Colorado limited liability company del /aft ,...C its! STATE OF COLORADO ) ss. COUNTY/CITY OF \utc The foregoing instrument was acknowledged before me this 2.day of r-Dp,ctexn+�.cr' , 2022, by t'A(W2e,t aA,q--2rve' the QEttU'Y' of Michael Boulter Farms, LLC, a Colorado limited liability company, on behalf of the limited liability company. Witness my hand and official seal My commission expires: �.�n.9 3/1-a23 My Notary number is: 2otS4o3o3S8' c3Vde QeelAci.\\_„ Notary Public 49 CHRYSTAL B BEACH NOTARY PUBLIC - STATE OF COLORADO NOTARY ID 20154030358 MY COMMISSION EXPIRES AUG 3, 2023 Error! Unknown document property name. 4878921 01/27/2023 09:25 AM Page 3 of 4 IN WITNESS WHEREOF, the undersigned have caused this instrument to be executed as of the date first written above. OPERATOR Cloudbreak Energy Partners, LLC, a Delaware limited liability company tar Title:. STATE OF COLORADO COUNTY OF \\Oa )ss. The foregoing instrument was acknowledged before me this Z q day of 2O 1, by s .s Re\ , the -es 1-d Leto of Cloudbreak Energy Partners, LLC, a Delaware limited liability company, on behalf of the limited liability company. Witness my hand and official seal My commission expires: 3/ 2023 50 CHRYSTAL B BEACH NOTARY PUBLIC STATE OF COLORADO NOTARY 1D 20154030358 MY CO MISSION EXPIRES AUG 3, 2023 Error! Unknown document property name. 4878921 01/27/2023 09:25 AM Page 4of4 Legal Description of Owner's Property A portion of the following real property located in the County of Weld, State of Colorado: LOT D OF RECORDED EXEMPTION NO. 105544-3 RE -4420, RECORDED AUGUST 16, 2006 AT RECEPTION NO. 3412407, BEING A PORTION OF THE SW1/4 OF SECTION 14, TOWNSHIP 4 NORTH, RANGE 65 WEST OF THE 6Th P.M., COUNTY OF WELD, STATE OF COLORADO. also known by street and number as: 0 County Road 44, La Salle, CO 80645 Error! Unknown document property name. 4886934 03/16/2023 12:00 PM Total Pages: 4 Rec Fee: $28.00 Carly Koppes - Clerk and Recorder, Weld County , CO FIRST AMENDMENT TO LEASE AND EASEMENT OPTION AGREEMENT This FIRST AMENDMENT TO LEASE AND EASEMENT OPTION AGREEMENT ("Amendment") is by and between Cloudbreak Energy Partners, LLC, a Delaware limited liability company ("Operator") and Michael Boulter Farms, LLC, a Colorado limited liability company ("Owner") as of the last date of execution of this Amendment. BACKGROUND A. Owner and Operator entered into that certain Lease and Easement Option Agreement dated December 29, 2022 (the "Original Lease"). The Original Lease and this Amendment shall be known as the "Lease." B. Owner and Operator intend to clarify certain provisions of the Original Lease to fully express the intent of their agreement subject to the terms of this Amendment. AGREEMENT A NOW, THEREFORE, in consideration of the mutual covenants and agreements contained in this Amendment and other good and valuable consideration, the receipt and sufficiency of which is acknowledged by each party, the parties to this Amendment mutually covenant and agree as follows: 1. Definitions and Recitals. Unless the context clearly indicates otherwise, all capitalized terms used but not otherwise defined in this Amendment shall have the meaning set forth in the Original Lease. The above recitals are incorporated into this Amendment by reference. 2. Owner's Property. Exhibit A to the Lease is hereby deleted in its entirety and replaced by Exhibit A, attached hereto and incorporated herein. 3. Remaining Option Term. Nothing in this Amendment shallbe deemed to amend or alter the Option Term or the Option, except as it relates to the definition of Owner's Property. The Option Term expires on December 29, 2025 and Operator retains the right to extend to the Extended Option Term. 4. Counterparts. This Agreement may be signed separately in one or more counterparts each of which shall be deemed an original and, when so executed, all such counterparts shall be deemed a single instrument binding upon the parties notwithstanding the fact that all parties have not signed the same counterpart. Original signatures transmitted by facsimile, e-mail, DocuSign, or in pdf format shall be deemed originals for all purposes of the Lease with full, binding effect. 5. Precedence. All other terms, provisions and conditions set forth in the Lease remain unaffected. In the event of any conflict or inconsistency between the provisions of this Amendment and the provisions of the Original Lease, the provisions of this Amendment shall govern and control. 1 4872-3583-3685.2 4886934 03/16/2023 12:00 PM Paget of4 6. Successors and Assigns. This Amendment shall be binding upon Owner and Operator, and their respective successors and assigns. 7. Governing Law. This Amendment shall be governed by, and construed in accordance with, the applicable laws of the State of Colorado, without regard to the conflicts of law provisions thereof or of any other jurisdiction. 8. Captions. The captions and headings used in this Amendment are for convenience only and do not in any way limit, amplify, or otherwise modify the provisions of this Amendment. 9. Entire Agreement. The Lease sets forth the entire agreement between the parties relative to the subject matter of the Lease, and there are no oral or written agreements between the parties, nor any representations made by either party relative to the subject matter hereof, which are not expressly set forth in the Lease. [Remainder of page intentionally blank. Signature page follows.] 2 4872-3583-3685.2 4886934 03/16/2023 12:00 PM Page 3 of 4 IN WITNESS WHEREOF, the parties have executed this Amendment as of the date of the last signature below. OWNER Michael Boulter Farms, LLC, a Colorado limited liability company BYneh!/f Name: Michael Boulter Title: Partner Date: Ly / 3/4 �Q' 2-3 A OPERATOR Cloudbreak Energy Partners, LLC, a Delaware limited liability company By: RSeu'a' jailielit,r' Name: Rebecca Gallery Title: Authorized Signatory Date: 3/13/2023 [Remainder of page intentionally blank. Exhibit A follows.] 5 la 3 4872-3583-3685.2 4886934 03/16/2023 12:00 PM Page 4of4 EXHIBIT A OWNER'S PROPERTY All of the following real property located in the County of Weld, State of Colorado: Legal Description: LOT D OF RECORDED EXEMPTION NO. 105544-3 RE -44420, RECORDED AUGUST 16, 2006 AT RECEPTION NO. 3412407, BEING A PORTION OF THE SW1/4 OF SECTION 14, TOWNSHIP 4 NORTH, RANGE 65 WEST OF THE 6TH P.N., COUNTY OF WELD, STATE OF COLORADO. also known by street and number as: 0 County Road 44, La Salle, CO 80645 Parcel number: 105514300030 Depiction of Owner's Property: virtaiSzvss A Fctstegiir^.';%:% .PJr:.xteA Jv ttn01 {:4;A £e?1�:ee% .� �,C'wy. hi: � :: C.�L.N.:::Rlr'�RY,'!°i'�iee: • .LyNi� �SrfL..:'�iiAW.:;e.,r,• Mucci 11) 1 n'S 1-4 ;000l() Proposed Leased Premises Owner's Property Proposed Leased Premises, to be finalized and confirmed pursuant to Sections 3.6 and 4.2. 4 4872-3583-3685.2 OPERATING AGREEMENT FOR MICHAEL BOULTER FARMS, LLC A COLORADO LIMITED LIABILITY COMPANY THIS AGREEMENT is made and entere d into effective this gt day of December, 2014, by and between, Michael Boulter Farms, LLC, a Colorado Limited Liability Y(the Com an p "Company"), and the Boulter Family Limited Liability Limited Partnership, RLLLP, hereinafter referred to as "Member". WITNESSETH: IT IS AGREED, in consideration of the promises, covenants, performance, and mutual consideration herein as follows: I. FORMATION OF COMPANY 1.1 Articles of Organization. This Company is organized pursuant to the provisions of the Limited Liability Company laws of the State of Colorado and pursuant to Articles of Organization filed with the Secretary of State on , 2014. The rights and obligations of the Company and the Members shall be provided in the Articles of Organization and this Operating Agreement. 1.2 Conflict between Articles of Organization and this Agreement. If there is any conflict between the provisions of the Articles of Organization and this Operating Agreement, the terms of this Operating Agreement shall control. II. CAPITAL CONTRIBUTIONS 2.1 Contributions. The capital contributions to be made by the Members and with which the Company shall begin business are as follows Member Name Contribution Boulter Family Limited Liability 100% Interest in Limited Partnership, RLLLP 2.2 Additional Capital Contributions. In the event that the cash funds of the Company are insufficient to meet its operating expenses or to finance new investments deemed appropriate to the scope and purpose of the Company as determined by the Managers, the Members shall make additional capital contributions, in the proportion of their ownership. The amount of the additional capital required by the Company and the period during which such additional capital shall be retained by the Company shall be determined by the Managers. 2.3 Loans. In lieu of voting an additional assessment of capital to meet the operating expenses or to finance new investments, the Company may, as determined by the Managers, borrow money from one or any of the Managers, Members, or third persons. In the event that a loan agreement is negotiated with a Manager or Member, he or she shall be 1 entitled to receive interest at a rate and upon such terms to be determined by the Managers, excluding the Manager making said loan, if applicable, and said loan shall be repaid to the Manager or Member, with unpaid interest, if any, as soon as the affairs of the Company will permit. The loan shall be evidenced by a promissory note secured by the assets of the Company. Such interest and repayment of the amounts so loaned are to be entitled to priority of payment over the division and distribution of capital contributions and profit among Members. III, MEMBERS' ACCOUNTS; ALLOCATIONS OF PROFIT AND LOSS; DISTRIBUTIONS 3.1 Capital Accounts. A separate capital account shall be maintained for each Member. The capital accounts for each Member shall initially reflect the amounts specified in Section 2.1, and, if a Member has merely promised to contribute the amount specified in Section 2.1, the Company shall maintain a corresponding subscription receivable on behalf of that Member. No Member shall withdraw any part of his or her capital account, except upon the approval of the Managers. If the capital account of a Member becomes impaired, or if he or she withdraws said capital account with approval of the Managers, his or her share of the subsequent Company profits shall be credited first to his or her capital account until that account has been restored, before such profits are credited to his or her income account. If, during the period when a Member's capital• account is impaired or he or she has withdrawn funds therefrom as hereinbefore provided, an additional contribution is required of the Members for the purposes specified in Section 2.2, then the Member with such withdrawn or impaired capital account shall be required to contribute his or her proportionate share of the additional capital contribution and the deficiency then existing in his or her capital account, so as to return the capital account to the same proportion existing as of the date of the additional contribution. No interest shall be paid on any capital contributions to the Company. 3.2 Income Accounts. A separate income account shall be maintained for each Member. Company profits, losses, gains, deductions, and credits shall be charged or credited to the separate income accounts annually unless a Member has no credit balance in his or her income account, in which event losses shall be charged to his or her capital account, except as provided in Section 3.1. The profits, losses, gains, deductions, and credits to the Company shall be distributed or charged to the Members as provided in Section 3.3. No interest shall be paid on any credit balance in an income account. 3.3 Allocations among Members. The ownership, profits and losses of the Company shall be divided or allocated in the following proportions: Name Percentage Boulter Family Limited Liability Limited 100% Partnership, RLLLP 3.4 Disproportionate Capital Accounts. No interest or additional allocation of profits, losses, gains, deductions, and credits shall inure to any Member by reason of his or her capital account being proportionately in excess of the capital accounts of the other Members. 2 3.5 Distribution of Assets. 3.5.1 All distribution of assets of the Company, including cash, shall be made in the same allocations among Members as described in Section 3.3. 3.5.2 The Managers shall determine, in their discretion, whether distributions of assets of the Company should be made to the Members; provided, however, that no distribution of assets may be made to a Member if, after giving effect to the distribution, all liabilities of the Company, other than liabilities to Members on account of their capital and income accounts, would exceed the fair market value of the Company assets. 3.5.3 A Member has no right to demand and receive any distribution from the Company in any form other than cash. IV. RULES RELATING TO THE MEMBERS 4.1 Admissions of New Members. Additional Members may be admitted upon the unanimous written consent of all Members. 4.2 Voting of Members. A Member shall be entitled to vote his or her percentage interest on any matter for which Members are required to vote. A Member may vote in person or by proxy at any meeting of Members. All decisions of the Members shall be made by a majority vote of the Members' percentage interest at a properly called meeting of the Members at which a quorum is present, or by unanimous written consent of the Members. In certain instances under this Agreement, a "super majority vote" may be required for the Members to act. This vote shall require a vote of not less than sixty-six and two thirds percent (66 2/3%) of all Members' percentage interest. 4.3 Meetings of Members. 4.3.1 Meetings of Members may be held at such time and place, either within or without the State of Colorado, as may be determined by the Managers or the person or persons calling the meeting, or they may be held telephonically. 4.3.2 An annual meeting of the Members shall be held in the second week of August of each year. 4.3.3 Special meetings of the Members may be called by the Managers or by a Member entitled to vote at the meeting. 4.3.4 Written notice stating the place, day, and hour of the meeting and, in the case of a special meeting, the purpose for which the meeting is called, shall be delivered not less than ten (10) days nor more than sixty (60) days before the date of the meeting, either personally or by mail, by or at the direction of the Managers or any other person calling the meeting, to each Member of record entitled to vote at such meeting. 'A waiver of notice in writing, signed by the Member before, at, or after the time of the meeting stated in the notice shall be equivalent to the giving of such notice. 3 4.3.5 By attending a meeting, a Member waives objection to the lack of notice or defective notice unless the Member, at the beginning of the meeting, objects to the holding of the meeting or the transacting of business at the meeting. A Member who attends a meeting also waives objection to consideration at such meeting of a particular matter not within the purpose described in the notice unless the Member objects to considering the matter when it is presented. 4.3.6 The Members may act on any matter by unanimous written consent in lieu of a meeting. 4.4 Quorum and Adjournment. A majority of the Members entitled to vote shall constitute a quorum at the meeting of Members. If a quorum is not represented at any meeting of the Members, such meeting may be adjourned for a period not to exceed sixty (60) days at any one adjournment; provided, however, that if the adjournment is more than thirty (30) days, a notice of the adjourned meeting shall be given to each Member entitled to vote at the meeting. 4.5 Extraordinary Acts. The Company shall undertake certain acts ("Extraordinary Acts") only on super majority vote of the Members. Extraordinary Acts are limited to the following: 4.5.1. Sales or Disposition of substantially all the assets, merger, dissolution, or bankruptcy of the Company; three years; 4.5.2. Acquisition or sale of real property or lease of real property for more than 4.5.3. Purchase, lease, or other acquisition of personal property having a cost to the Company of greater than $25,000.00; and $25,000.00. 4.5.4. Incurrence of debt or other contractual obligation of greater than V. RULES RELATING TO MANAGERS 5.1 General Powers. Management and the conduct of the business of the Company shall be vested in the Managers. The Managers may adopt resolutions to govern their activities and the manner in which they shall perform their duties to the Company. 5.2 Qualifications of Managers. Managers shall be natural persons eighteen (18) years of age or older. 5.3 Number, Election; and Term. 5.3.1 The initial number of Managers shall be two (2). The number of Managers may be increased or decreased by the vote or consent of the Members. 5.3.2 The initial Managers shall hold office until the first annual meeting of Members and until their successors have been elected and qualified. Thereafter, each 4 Manager elected by the Members shall hold office for a one-year term or until his or her successor has been elected and qualified. 5.3.3 Managers shall be elected by a vote or consent of the Members at an annual meeting or at a special meeting called for that purpose. 5.4 Meetings and Voting. 5.4.1 Meetings of the Managers may be held at such time and place as the Managers by resolution shall determine, or they may be held telephonically. 5.4.2 Written notice of meetings of the Managers shall be delivered at least twenty-four (24) hours before the meeting personally, by telecopier, or by mail actually delivered to the Managers within the twenty-four (24) hour period. A waiver of notice in writing, signed by the Manager before, at, or after the time of the meeting stated in the notice, shall be equivalent to the giving of such notice. 5.4.3 By attending a meeting, a Manager waives objection to the lack of notice or defective notice unless, at the beginning of the meeting, the Manager objects to the holding of the meeting or the transacting of business at the meeting. 5.4.4 A majority of the Managers entitled to vote shall constitute a quorum at the meeting of Managers. 5.4.5 All decisions of the Managers shall be made by a majority vote of the Managers at a properly called meeting of the Managers at which a quorum is present, or by unanimous written consent of the Managers. 5.5 Duties of Managers. 5.5.1 The Managers shall have the duties and responsibilities as described in the Colorado Limited Liability Company Act, as amended from time to time. 5.5.2 The Managers, or any one of the Managers as designated by resolution of the Managers, shall execute any instruments or documents providing for the acquisition, mortgage, or disposition of the property of the Company. 5.5.3 Any major debt (§4.5.4) contracted or liability incurred by the Company shall be authorized only by a resolution of the Managers, and any instruments or documents required to be executed by the Company shall be signed by the Managers or any one of the Managers as designated by resolution of the Managers. 5.5.4 The Managers may designate any one of the Managers or delegate an employee or agent to be responsible for the daily and continuing operations of the business affairs of the Company. All decisions affecting the policy and management of the Company, including the control, employment, compensation, and discharge of employees; the employment of contractors and subcontractors; and the control and operation of the premises and property, including the improvement, rental, lease, maintenance, and all other matters pertaining to the operation of the property of the business shall be made by the Managers. 5 5.5.5 Any Manager may draw checks upon the bank accounts of the Company and may make, deliver, accept, or endorse any commercial paper in connection with the business affairs of the Company consistent with appropriate and approved banking resolutions. 5.5.6. Each Manager shall have full authority to execute all documents, instruments, contracts and other writings affecting or involving the Company or Company Property which have been approved, agreed to or adopted by the Company. Notwithstanding anything here to the contrary, a Manager may not undertake any Extraordinary Acts except in accordance with Section 4.5. 5.6 Devotion to Duty. At all times during the term of a Manager, a Manager shall give such time, attention, and effort to the business of the Company as may be reasonably required; and shall, with reasonable skill and power, exert himself or herself for the joint interest, benefit, and advantage of the Company; and shall truly and diligently pursue the Company's objectives. 5.7 Indemnification. Managers, Members, employees, and agents of the Company shall be entitled to be indemnified by the Company to the extent provided in the Colorado Limited Liability Company Act, as amended from time to time, and shall be entitled to the advance of expenses, including attorneys' fees, in the defense or prosecution of a claim against him or her in the capacity of Manager, Member, employee, or agent. VI. BOOKS 6.1 Location of Records. The books of the Company shall be maintained by the Manager at the principal office of the Company or at such other place as the Managers by vote or consent shall designate. 6.2 Access to Records and Accounting. Each Member shall at all times have access to the books and records of the Company for inspection and copying. Each Member shall also be entitled: 6.2.1 To obtain from the Managers upon reasonable demand for any purpose such information reasonably related to the Member's Membership Interest in the Company; 6.2.2 To have true and full information regarding the state of the business and financial condition and any other information regarding the affairs of the Company. 6.2.3 To have a copy of the Company's federal, state, and local income tax returns for each year promptly after they are available to the Company; and 6.2.4 To have a formal accounting of the Company affairs whenever circumstances render an accounting just and reasonable. 6.3 Accounting Rules. The books shall be maintained on a cash basis. The fiscal year of the Company shall be the calendar year. Distributions to income accounts shall be made annually. The books shall be closed and balanced at the end of each calendar year and, if an audit is determined to be necessary by vote or consent of the Managers, it shall be made 6 as of the closing date. The Managers may authorize the preparation of year-end profit -and -loss statements, balance sheet, and tax returns by a certified public accountant. VII. DISSOLUTION 7.1 Causes of Dissolution. The Company may be dissolved upon the occurrence of any of the following events: 7.1.1 At any time by a super majority vote or a unanimous written consent of the Members. 7.1.2 Upon the death, retirement, disability, resignation, expulsion, bankruptcy, or dissolution (non -marital) of a Member (withdrawn Member), or a prohibited transfer of a Member's interest, subject to §7.2. 7.1.3 On the sale of all or substantially all of the assets of the Company. 7.2 Continuation of Business. 7.2.1 Continuation in General. Notwithstanding a dissolution of the Company under Section 7.1.3, the remaining Members may elect to continue the business of the Company. The election shall occur within ninety (90) days of the event of dissolution. 7.3 Computation of the Purchase Price of Withdrawn Member's Membership Interest. a. If the remaining Members elect to continue the business under Section 7.2 of the Operating Agreement, the remaining Members shall purchase the Withdrawn Member's membership interest at a price which shall be determined by an independent certified or qualified real estate appraiser (the "appraiser"). The appraiser shall be selected by the then current Company accountant. In the event any Member is dissatisfied with the purchase price which is determined by the appraiser selected by the Company's accountant (hereinafter the "CPA"), the Company shall retain the services of an appraiser. The appraiser shall be chosen by the Member who is unsatisfied with the appraisal performed by the first appraiser. In the event any Member is dissatisfied with the appraisal performed by the second appraiser, the Company shall hire a third appraiser. The third certified or qualified real estate appraiser shall be chosen by the member who is dissatisfied with ith the second appraiser's appraisal. After the preparation of the appraisal by the third appraiser, the purchase price shall be calculated as the average of the three (3) purchase prices determined by the first, second and third appraisers. 7 The Company shall pay for the appraisals prepared by all three (3) real estate appraisers. The purchase price is subject to setoff for any damages incurred as a result of the Withdrawn Member's actions, and nothing in this paragraph is intended to impair p the Company's right to recover damages for the Withdrawn Member's wrongful dissolution of the Company by reason of the Withdrawn Member's expulsion, retirement, resignation, or bankruptcy. b. The purchase price determined under Paragraph 7.3 (a), above, shall be paid to the Withdrawn Member as follows: i In cash or other good funds. ii. By Promissory Note. The underlying Note for any purchase may be for as long as ten (10) years with interest accruing thereon at the rate of Prime plus one percent (1%), with the interest rate to be adjusted annually to adjust to changes in the prime rate, with payments made monthly, or as otherwise agreed. iii. Or as is agreed upon between the parties. c. The Effective Date shall be the date of death of a deceased Member; the date personal notice is received, or the date the certified mail is postmarked, in the case of a retired, resigned, or expelled Member; or the date the notice is delivered to the Withdrawn Member or to the place of business of the Company, in case of bankruptcy of a Member. d. The remaining Members may use the assets of the Company to effectuate the purchase. 7.4. Distribution of Assets if Business is not Continued. In the event of dissolution of the Company where the Members do not elect to or are unable to continue the business of the Company under Paragraph 7.2, the Managers shall proceed with reasonable promptness to liquidate the assets of the Company. Upon dissolution, the assets of the Company shall be used and distributed in the following order first be paid; a Any liabilities and liquidating expenses of the Company will t. b. The reasonable compensation and expenses of the Managers in liquidation shall be paid; c. The amount then remaining shall be distributed among the Members in accordance with their ownership interest. 8 VIII. EXPULSION OF A MEMBER. 1. Causes of Expulsion. A Member may be expelled from the Company upon the occurrence of any of the following events: a If a Member materially violates any of the provisions of this Agreement; b. If a Member's membership Interest becomes subject to a charging order, attachment or tax lien, which is not dismissed or resolved to the satisfaction of the Managers of the Company within sixty (60) days after assessment or attachment; or c. If a super majority of Members vote to expel. 2. Notice of Expulsion. ' Upon the occurrence of an event described in Section 8.1, written notice of expulsion shall be given to the violating Member either by serving the same by personal delivery or by mailing the same by certified mail to his or her last known place of residence, as shown on the books of said Company. Upon the receipt of personal notice, or the date of the postmark for certified mail, the violating Member shall be considered expelled, and shall have no further rights as a Member of the Company, except to receive the amounts to which he or she is entitled under Paragraph 7.3 or 7.4, above. IX. BANKRUPTCY OF A MEMBER. 1. Bankruptcy Defined. A Member shall be considered bankrupt if the Member files a petition in bankruptcy (or an involuntary petition in bankruptcy is filed against the Member and the petition is not dismissed within sixty (60) days) or makes an assignment for the benefit of creditors or otherwise takes any proceeding or enters into any agreement for compounding his or her debts other than by the payment of them in the full amount thereof, or is otherwise regarded as insolvent under any Colorado insolvency act. 2. Effective Date for Bankruptcy. The Effective Date of a Member's bankruptcy shall be 'the date. that the Managers, having learned of the Member's bankruptcy, give notice in writing stating that the Member is regarded as bankrupt under this Agreement, such notice to be served personally or by leaving the same at the place of business of the Company. As of the Effective Date, the bankrupt Member shall have no further rights as a Member of the Company, except to receive the amounts to which he/she is entitled under Paragraph 7.3 or 7.4. 9 X. RETIREMENT, RESIGNATION OR DISABILTY OF A MEMBER. 1. Right to Retire or Resign. A Member shall have the right, at any time, to retire or resign as a Member of the Company by giving three (3) months' notice to the Company at the Company's place of business. 2. Consequences of Retirement, Resignation or Disability if the Business is Continued. a. Upon giving notice of an intention to retire or resign or upon notice of a disability, the Withdrawn Member may have his or her Membership Interest purchased as provided in Paragraph 7.3 if the remaining Members elect to continue the business under Paragraph 7.2; however, the Continuing Members are not required to purchase the Membership Interest of the Withdrawn Member. Upon receipt of notice of the remaining Members' election to continue the business, the Membership Interest of the Withdrawn Member in the Company shall cease and terminate, and the Withdrawn Member shall only be entitled to the payments provided in Paragraph 7.3. • b. Notwithstanding anything stated elsewhere in this Agreement, a Member who has resigned, retired or is disabled may, at his sole option, retain his membership interest in the Company, and all rights and benefits of such membership, if the Members elect to continue the Company after such resignation, retirement or disability. However, a Member who has retired, resigned or has become disabled shall not be the manager of the Company or participate in the management of the Company. 3. Consequences of Retirement, Resignation or Disability if the Business is Not Continued. If the remaining Members elect not to continue the business upon retirement, resignation or disability of a Member, or are unable to do so by law, the Withdrawn Member shall only be entitled to his or her interest in liquidation, as stated in Paragraph 7.4, subject to any setoff for damages caused by the Member's retirement, resignation or disability. 4. DISABILITY. Disability shall be defined as the inability of a member to substantially perform the normal duties of said Member's employment or the normal and customary business participation functions of a member for a period of six (6) months. The company, in making a determination and finding of such disability, may rely on the best data and information available to it and, in the event of disability arising out of physical or mental illness or injury, the subject member agrees to submit to reasonable a medical examination by medical doctors and experts of the reasonable choice of the company which shall bear the expense thereof. This section will not apply pY in a case where interests in the company are owned in joint tenancy and only one of the joint tenants is disabled. XI. DEATH OF A MEMBER. 1 Surviving Spouse or Estate May Retain Membership Interest. a. Upon the death of a Member, the surviving spouse or Estate shall not be required to sell the deceased Member's interest in the Company. The surviving spouse or the deceased's Estate may choose to retain the membership interest of the deceased Member. In this case, the surviving spouse or the Estate of the deceased, while retaining membership rights to share in profits, shall not be a manager or participate in management of the Company. b. The intent of the Members is to allow the surviving spouse or the Estate (or the children of the deceased Member if the surviving spouse has also predeceased) to benefit from the income from the Company, but not for the surviving spouse or the Estate to manage or control the Company. The surviving Members may not force the surviving spouse or the Estate of the Deceased to sell, but the surviving spouse or the Estate does have the right and option to sell the interests to the surviving Members. The decisions of the surviving Members shall be controlling. For example, if the surviving Members choose to sell to `a third party, then the surviving spouse or the Estate shall also sell. If the surviving Members elect to make improvements on the real property, then the surviving spouse or the Estate of the deceased shall cooperate and agree. 2. If Surviving Spouse or Estate Do Not Want to Retain Membership Interest. If the surviving spouse or the Estate of the deceased Member choose not to become a member and wish instead to sell the membership interest of the deceased Member, upon the death of a Member, the deceased Member's rights as Member of the Company shall cease and terminate except as provided in this Section XI. 3. Consequences of Death if Business is Continued and the Surviving Spouse or Estate Wish to Sell. If the surviving Members elect to continue the business as provided in Paragraph 7.2 and the surviving spouse or Estate wish to sell, the Managers shall serve notice in writing of such election, within sixty (60) days after the death of the decedent, upon the executor or administrator of the decedent, or, if at the time of such election no legal representative has been appointed, upon any one of the known legal heirs of the decedent at the last known address of such heir. The Members shall purchase the Membership Interest of the deceased Member as provided in in Paragraph 7.3, and the closing of such purchase shall be within sixty (60) days of the Y notice of such election. 4. Consequences of Death if the Business is Not Continued. If the surviving Members do not elect to continue the business or are unable to do so b law, insurance,by and there is no life the deceased Member's surviving spouse or Estate shall only be entitled to her/his or its interest in liquidation as stated in Paragraph 7.4. 11 XII. SALE OF MEMBERSHIP INTERESTS. 1. Offer to Purchase Interests. In the event a Member or the company receives a bonafide offer to purchase all or any pad of the ownership interests in the company, a copy of said offer, with all pertinent information, shall be promptly sent to all members and to the company. Each of the members, respectively, on a prorata basis as to such members, shall have the first right of refusal to meet the offer and to so acquire the interests subject to the offer. The company shall have the second right of first refusal to meet the offer and to so acquire the interests subject to the offer. Each such right of the member and the company shall be exercisable within thirty (30) days of receipt of notice of said offer. In exercising this right, the member and/or the company must meet the terms and conditions of the third party offer. To the extent the rights of first refusal provided herein are not exercised, the member receiving such bonafide offer may proceed to sell his interests to the offeror, subject to the terms of this Agreement. The failure of a member or the company to exercise this right shall not constitute a waiver of such right as to any other third party offers to purchase interests of the Company. 2. Prohibited Transfers. Any purported transfer of a membership interest that is not a permitted transfer shall be null and void and of no force or effect whatever; provided that, if the Company is required to recognize a transfer that is not a permitted transfer (or if the Company, in its sole discretion, elects to recognize a transfer that is not a permitted transfer), the membership interest transferred shall be strictly limited to the transferor's rights to allocations and distributions as provided by this Agreement with respect to the transferred membership interest, which allocations and distributions may be applied (without limiting any other legal or equitable rights of the Company) to satisfy any debts, obligations, or liabilities for damages that the transferor or transfer of the membership interest may have to the Company. Y In the case of a transfer or attempted transfer of a membership interest that is not a permitted transfer, the parties engaging or attempting to engage in the transfer shall be liable to indemnify and hold harmless the Company and the other Members from all cost, liability, and damage that any of the indemnified Members may incur (including, without limitation, incremental tax liabilities, lawyers fees and expenses) as a result of the transfer or attempted transfer and efforts to enforce the indemnity granted by this Agreement. 3. Rights of Unadmitted Assignees. A person or entity that acquires a membership interest but is not admitted as a substituted Member shall be entitled only allocations and distributions with respect to the membership interest in accordance with this Agreement, and shall have no right to any information or accounting of the affairs of the Company, and shall not be entitled to inspect the books or records of the Company, and shall not have any rights of a Member under the Colorado Limited Liability Company Act or this Agreement. XIII. MEMBERS' COVENANTS 13.1 Member's Personal Debts. In order to protect the property and assets of the Company from any claim against any Member for personal debts owed by such Member, each Member shall promptly pay all debts owing by him or her and shall indemnify the Company from any claim that might be made to the detriment of the Company by any personal creditor of such Member. 12 13.2 Alienation of Membership Interest. No Member shall, except as provided in Article XII, sell, assign, mortgage, pledge or otherwise encumber his or her Membership Interest in the Company or in its capital assets or property; or enter into any agreement of any kind that will result in any person, firm, or other organization becoming interested with him or her in the Company; or do any act detrimental to the best interests of the Company. XIV. ARBITRATION 14.1 Arbitration. Any dispute, claim, or controversy arising out of or relating to this Agreement or the breach thereof shall be settled by arbitration in accordance with the rules then obtaining of the American Arbitration Association. Judgment upon the award rendered by said arbitration may be entered in any court having jurisdiction thereof. Costs of arbitration shall be paid by the loser. If one Member notifies the other Member in writing of a dispute, claim, or controversy within six (6) months of the arising of such dispute, claim, or controversy and requests that the same be arbitrated, no legal action may then be commenced thereon, except to obtain judgment on the arbitration award. A XV. MISCELLANEOUS PROVISIONS 15.1 Inurement. This Agreement shall be binding upon the parties hereto and their respective heirs, executors, administrators, successors, and assigns, and each person entering into this Agreement acknowledges that this Agreement constitutes the sole and complete representations made to him or her regarding the Company, and its purpose and business, and that no oral or written representations or warranties of any kind or nature have been made regarding the proposed investments, nor any promises, guarantees, or representations regarding income or profit to be derived from any future investment. 15.2 Modification. This Agreement may be modified from time to time as necessary only by the written agreement of the Company, acting through the vote or consent of its Managers, and the Members. 15.3 Severability. The provisions of this Agreement are severable and separate, and if one or more is voidable or void by statute or rule of law, the remaining provisions shall be severed therefrom and shall remain in full force and effect. 15.4 Governing Law/Jurisdiction. This Agreement and its terms are to be construed according to the laws of the State of Colorado. Jurisdiction for any dispute hereunder shall be exclusively proper in Larimer County, Colorado. 15.5 Counterparts. This Agreement has been executed in counterparts and each such counterpart shall be deemed an original of the Agreement for all purposes. 15.6 Entire Agreement. This Agreement and exhibits attached to it set forth all (and are intended by all parties to be an integration of all) of the promises, agreements, conditions, understandings, warranties, and representations among the parties with respect to the Company; and there are no promises, agreements, conditions, understandings, warranties, or 13 representations, oral or written, express or implied, among them other than as set forth in this Agreement. 15.7 Severability. Nothing contained in this Agreement shall be construed as requiring the commission of any act contrary to law. In the event there is any conflict between any provision of this Agreement and any statute, law, ordinance, or regulation contrary to which the Members or the Company have no legal contract, the latter shall prevail, but in that event the provisions of this Agreement thus affected shall be curtailed and limited only to the extent necessary to conform with the requirement of law. In the event that any part, article, section, paragraph, or clause of this Agreement shall be held to be indefinite, invalid, or otherwise unenforceable, the entire Agreement shall not fail on account of that holding, and the balance of the Agreement shall continue in full force and effect. 15.8 Interest of Member. The fact that a Member, or any employee, partner, officer or director of a Member, or a member of any Member's immediate family, or a member of any employee's, officer's, director's, or partner's family, is employed by, or is directly interested in or connected with any person, firm or corporation engaged by the Company to render or perform any service, or from whom or which the Company may lease its property, shall not prohibit the Company from so dealing with that person, firm or corporation provided the arrangement does not obligate the Company to pay compensation for or on account of any service on terms which are less favorable to the Company than are available from others on an arms -length basis in the same geographical area. 15.9 Legal Title. Legal title to the Company's property shall be held in the name of the Company, or in whatever other manner is in the best interests of the Company as determined by the Managers. It is expressly understood and agreed that the manner of holding title to the Company's property is solely for the convenience of the Company; accordingly, the distributees, successors and assigns of any Member shall have no right, title or interest in or to the Company's property by reason of the manner in which title is held, but the Company's property shall be treated as Company property subject to the terms of this Agreement. No Member shall commence an action for partition with respect to any asset owned by the Company. IN WITNESS WHEREOF, we have hereunto set our hands and seals on the day first written above. MEMBER: Boulter Family Limited Liability Limited Partnership, RLLLP By: Michael J. Boulter. by Daisy oulter, Manager CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Alternatives Statement Cloudbreak Energy Partners performed a rigorous search for ideal solar project locations across the State of Colorado. This search included hundreds, if not thousands, of properties within Weld County. The Boulter's property was chosen due to several factors including, but not limited to: • Close proximity to high quality Xcel Energy distribution infrastructure that has the capacity for a project of this size • Close proximity to Xcel Energy's Box Elder substation • Outside of floodplains and wetlands • Relatively flat • No geotechnical constraints • Landowner participation • Limited disturbance to nearby properties and property owners Alternatives to the Boulter's property were thoroughly evaluated but were ultimately dismissed due to at least one of the above factors. The proposed Project presents the most viable design and location with the least adverse impacts of all the alternatives. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Development Standards Statement 1. Height limitation. Ground -mounted solar collectors shall not exceed twenty-five (25) feet in height, measured from the highest grade below each solar panel to the highest extent of the solar panel rotation.: o The ground -mounted solar collectors will not exceed 25' in height, as measured from the highest grade below each solar panel to the highest extent of the solar panel rotation. 2. Glare. Concentrated solar glare from solar collectors shall not be directed toward or onto nearby properties or roadways at any time of the day: o A glare study for the Project is included in the application materials. The risk of glare being directed toward or onto nearby properties or roadways will be mitigated with screening as described in the Landscape and Screening Plan. 3. Setbacks. The improved area shall conform to the setback requirements of the underlying zone. Additionally, the improved area must be at least five hundred (500) feet from existing residential buildings and residential lots of a platted subdivision or planned unit development. The residential setback requirement may be reduced if appropriate screening through landscape or an opaque fence is installed, or upon submittal to Weld County of a waiver or informed consent signed by the residence owner agreeing to the lesser setback. If landscaping or opaque fencing is substituted for setback, a landsca Ding plan or fencing plan shall first be submitted to and approved by the Department of Planning Services: o The Project conforms to the setback requirements of the Agricultural zone and is The project will be seeking waivers for neighbors within 500 feet of the project or using screening around the project near residences. 4. Dust mitigation. The operators of the SEF shall continuously employ the practices for control of fugitive dust detailed in their dust mitigation plan submitted as required by Subsection B.2., above: o The Project will continuously employ the practices for control of fugitive dust detailed in the submitted Dust Mitigation Plan. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE 2 5. Underground cables. All electrical cables on the improved area shall be buried, except for direct current string wires that connect between solar collectors, direct current collection circuits between rows of solar arrays that are no more than four (4) feet above grade crossings, substations, switchyards, and circuit voltages greater than 34.5 kilovolts (where necessary): a All electrical cables on the improved area shall be buried, except for direct current string wires that connect between solar collectors, direct current collection circuits between rows of solar arrays that are no more than four (4) feet above grade crossings, substations, switchyards, and circuit voltages greater than 34.5 kilovolts (where necessary). 6. Fencing. The SEF shall be enclosed with a security fence as approved pursuant t0 a fencing plan submitted to the Department of Planning Services. Appropriate signage shall be placed upon such fencing that warns the public of the high voltage therein: a The Project will be enclosed by a 7 foot tall game fence. Additional details are provided in the Landscape and Screening Plan as well as the USR Map. 7. Stormwater management. The Operator of the SEF shall submit a drainage report to comply with required Storm Drainage Criteria pursuant to Chapter 8, Article XI of this Code. Additional requirements for Municipal Separate Storm Sewer System (MS4) areas may be applicable pursuant to Chapter 8, Article IX of this Code. Ground -mounted solar collector systems shall be exempt from impervious surface calculations if the soil under the collectors is designated hydrologic A or B soil groups by the Natural Resources Conservation Service (NRCS): o A drainage report has been submitted as part of the Project's application. 8. Access permit. Prior to construction of the SEF, the applicant shall apply for and obtain an approved Access Permit from the Weld County Department of Public Works, pursuant to the provisions of Article XIV of Chapter 8 of this Code: a Prior to construction of the Project, CBEP Solar 26, LLC or its contractors shall apply for and obtain an approved Access Permit from the Weld County Department of Public Works pursuant to the provisions of Article XIV of Chapter 8 of this Code. 9. Existing irrigation systems. The nature and location or expansion of the SEF must not unreasonably interfere with any irrigation systems on or adjacent to the solar facility. a The Project will not interfere with any irrigation systems on or adjacent to the solar facility. (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Decommissioning Plan Approach CBEP Solar 26, LLC has developed this decommissioning plan for the Blue Spruce Solar Project, to be implemented after the contracted lease term has ended. CBEP Solar 26, LLC, the owner of the 10 MWac Solar Energy Facility (SEF) will be responsible for the decommissioning. Decommissioning of the Project will include removal of all above and below -ground infrastructure, including the arrays, inverter structures, concrete foundations and pads, and electrical infrastructure. All fences, graveled areas and access roads shall be removed unless landowner agreement to retain is presented, in writing, in which the property owner agrees for this to remain. The property shall be restored to a condition reasonably similar to its condition prior to development of the 10 MWac SEE Grading and re -vegetation will comply with all applicable rules and regulations. Exclusions from the decommissioning plan include planting trees, removing internal site roads, and re -grading to previous conditions. All non -utility owned equipment, conduits, structures, fencing, and foundations to a depth of at least 3' below grade shall be removed. Decommissioning activities will follow the CDOT best management practices (BMPs) for erosion and sediment control and stormwater management that are applied during project construction, or any new BMPs relevant at the time. CBEP Solar 26, LLC will decommission the Project once the contracted lease term is over, if the lease term is not extended or renewed. Decommissioning may also be initiated if the project is no longer viable, or in the case of a force majeure event (described below). CBEP Solar 26, LLC will provide notice to Weld County prior to commencement of decommissioning the Project. Estimated Timeline and Cost Decommissioning/reclamation shall commence within 12 months after power production has permanently ceased and be completed within 12 months from the start date of the decommissioning/reclamation work. Decommissioning/reclamation cost estimates, which shall be updated every five years from the establishment and submittal of the Security, shall include all costs associated with the dismantlement, recycling, and safe disposal of facility components and site reclamation activities, including the following elements: (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE 2 • All labor, equipment, transportation, and disposal costs associated with the removal all facility components from the facility site • All costs associated with full reclamation of the facility site, including removal of non-native soils, fences, and constructed access roads • All costs associated with reclamation of any primary agricultural soils at the facility site to ensure each area of direct impact shall be materially similar to the condition it was before construction • All decommissioning/reclamation activity management, site supervision, and site safety costs • All other costs, including administration costs, associated with the decommissioning and reclamation of the facility site • The established date of submission of the financial assurance mechanism to Weld County Prior to construction, CBEP Solar 26, LLC will provide the County with an irrevocable standby letter of credit, bond, or alternate form of financial assurance mechanism in an amount sufficient to fund the estimated decommissioning costs required by the Code. The Security shall: • Name the Board of County Commissioners of Weld County as the sole beneficiary of the letter of credit • Be issued by an A -rated financial institution based upon a rating provided by S&P, Moody's, Fitch, AM Best, or other rating agency with similar credentials • Include an automatic extension provision or "evergreen clause" • Be "bankruptcy remote", meaning the financial assurance mechanism will be unaffected by the bankruptcy of the SEF operator Weld County, in its sole discretion, may approve alternative forms of a financial assurance mechanism such as, but not limited to bonds, letters of credit, or other securities, if it finds that such alternative forms will provide an assurance of the availability of financial resources for decommissioning/reclamation that equals or exceeds that provided by the form required herein. Furthermore, Weld County shall have the right to draw upon the irrevocable standby letter of credit, or other form of financial assurance mechanism, to pay for decommissioning in the event that the holder has not commenced decommissioning/reclamation activities within 90 days of the Board of County Commissioners order or resolution directing decommissioning/reclamation. Continued Beneficial Use If prior to decommissioning the Project, the landowner determines that any of the Project components can be beneficially used on the land after disassembly, such items would be (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBF EAKENElRGY.COM CLOUDBREAK PAGE 3 exempt from the requirements for decommissioning. If a third party acquires the Project or a portion of the Project, such third party would be responsible for providing evidence of a plan of continued beneficial use for their relevant Project components. Force Majeure An exception to these requirements will be allowed for a force majeure event, which is defined as any event or circumstance that wholly or partly prevents or delays the performance of any material obligation arising under the Project permits, but only t0 the extent: • Such event is not within the reasonable control, directly or indirectly, of CBEP Solar 26, LLC (including without limitation events such as fire, earthquake, flood, tornado, hurricane, acts of God and natural disasters; war, civil strife or other similar violence); • CBEP Solar 26, LLC has taken all reasonable precautions and measures to prevent or avoid such event or mitigate the effect of such event on CBEP Solar 26, LLC's ability to perform its obligations under the Project permits and which, by the exercise of due diligence, it has been unable to overcome; and • Such event is not the direct or indirect result of the fault or negligence of CBEP Solar 26, LLC. In the event of a force majeure event, which results in the absence of electrical generation by the Project for 12 months, CBEP Solar 26, LLC must demonstrate to Weld County by the end of the 12 months of non -operation that the Project will be substantially operational and producing electricity within 24 months of the force majeure event. If such a demonstration is not made to Weld County's satisfaction, then decommissioning of the Project must be initiated 18 months after the force majeure event. (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKENEPGY.COM Kimley >) Horn DRAINAGE REPORT Blue Spruce Solar Weld County Case //USR23-0019 Northeast of the intersection of Weld County Rd 44 and Weld County Road 45 Weld County, CO Prepared by: Kimley-Horn Inc. 6200 South Syracuse Way, Suite 300 Greenwood Village, CO 80111 Contact: Adam Harrison, P.E. Phone: (303) 228-2311 Prepared on: August 30, 2023 Blue Spruce Solar — Weld County, CO August 2023 Page 1 Kimley >) Horn TABLE OF CONTENTS 1. PROJECT DESCRIPTION & SCOPE OF WORK 3 1.1. Project Location 3 1.2. Nearby Water Features & Ownership 4 1.3. Report & Analysis Methodologies 4 1.4. Stormwater Management 5 2. CONCLUSION 5 EXHIBITS Exhibit 1 - FEMA Firm Map Exhibit 2 - NRCS Report Exhibit 3 — NOAA Rainfall Data Exhibit 4 — Pre -Development Drainage Area Map Exhibit 5 — Post -Development Drainage Area Map Exhibit 6 — Hydrologic Calculations & Detention/WQCV Calculations Exhibit 7 — Hydrologic Response of Solar Farms Blue Spruce Solar — Weld County, CO August 2023 Page 2 Kimley >) Horn 1. PROJECT DESCRIPTION & SCOPE OF WORK The development is a proposed 10.0-MWac Solar power generating facility located in Weld County, CO. The solar power generating facility will consist of rows of Photovoltaic Solar Modules, gravel access driveways, associated electrical equipment, underground utilities, and a substation (by others). Solar modules will be mounted on piles and elevated above the ground as to preserve the existing underlying soil and allow for revegetation and infiltration. The project will be surrounded by a perimeter fence. Ground area within the limits of development that is not occupied by gravel roads or foundations will be seeded to establish permanent vegetation. This drainage narrative is intended to provide Weld County with preliminary information regarding the drainage and land disturbance activities related to the proposed Blue Spruce Solar, small scale solar facility (Project). The project will be designed and will be constructed and maintained in a manner that minimizes storm water related impacts, in accordance with Weld County drainage criteria. Project name, Property Address and Weld County Parcel No. Blue Spruce Solar, 22001-22999 WCR 44 Weld 80645, Parcel No. 105514300030 Developer/Owner CloudBreak Energy Partners, LLC, 218 S. 3rd Street Sterling, CO 80751 Urbanizing/Non-Urbanizing This site is located more than a quarter mile away from the nearest Weld County municipal boundary and is classified as "Non -Urbanizing". Therefore, detention ponds designed for this site would be sized using 10 -year runoff rates. 1.1. Project Location The existing site subject property is a parcel of 152.6 acres. The project is located on approximately 96.86 acres of lightly vegetated land. The project is located southeast of La Salle, within Weld County. The site is bounded to the north by property owned by Michael Boulter Farms LLC (Parcel 105514200025), to the east by parcel 105514000014 owned by the city of Broomfield, to the west by WCR 45 and to the south by WCR 44. Section Township Range Property is located within a portion of the southwest quarter of Section 14, Township 4 North, Range 65 West of the 6th P.M., Weld County, Colorado. Per FEMA Map Panels 08123C1750E effective 01/20/2016, none of the development area is within a flood hazard area. (Refer to Exhibit 1 for FEMA Map). The NRCS Report dated 04/28/2023, concludes that onsite soils consist mostly of Aquolls and Aquepts, Vona sandy loam and Vona loamy sand, and Otero sandy loam that classify as hydrologic soil groups (HSG) type A and D. The site was modeled using all type D soils. For additional detail, refer to Exhibit 2 for the NRCS Report. Blue Spruce Solar — Weld County, CO August 2023 Page 3 Kimley >) Horn 1.2. Nearby Water Features & Ownership In the existing condition, a majority of the site drains to the surrounding agricultural and lightly vegetated property of the same parcel number as the project site. The nearest water feature is Gilmore Ditch approximately 0.7 miles east of the project area. Gilmore Ditch is the receiving water of the project site. The existing drainage patterns will be maintained in the proposed condition. Refer to Exhibit 4 and Exhibit 5 for the Pre and Post -Development Drainage Area Maps. 1.3. Report & Analysis Methodologies This report evaluates the pre and post development runoff characteristics of the development (including solar facility footprint and access drive) and addresses the stormwater requirements of Weld County and the state of Colorado. Hydrologic Design Criteria The table below notes the hydrologic design criteria used in the analysis. Parameter Value Unit Reference Time of Concentration, Tc - min. Exhibit 6 Runoff Coefficient, C - - MHFD Criteria Manual, Chapter 6, Table 6-4 1 -hr Point Rainfall, P1 (100 -Year) 2.71 Inches NOAA Rainfall Data (Exhibit 3) Storm Runoff, Q - cfs Q = CIA Basin Conditions The drainage areas of the site are shown for the site as Pre -construction (Exhibit 4) and Post - construction (Exhibit 5). Pre -construction drainage basins were analyzed to calculate the peak existing runoff for the design storm. The total imperviousness for the existing site was calculated to be 2.0%. Post - construction drainage basins were analyzed to calculate the peak runoff for the design storm in the proposed site conditions. The Weld County Construction and Design Criteria requires areas of proposed solar arrays over a Type D soil classification to utilize an imperviousness of 25%. The total imperviousness for the proposed site was calculated to be 8.0% (see Exhibit 6 for the imperviousness summary). The area under the solar panels will be planted with a low - maintenance grass seed mix, in order to mimic natural processes to manage stormwater, which follows the Low -Impact Development (LID) approach. The existing drainage basins 1,3,5,8,9,10,12,13,14,16, and 20 under existing conditions currently pond across the site. The projects proposed conditions will utilize grading and storm infrastructure to create positive drainage of the entire site. The existing site use is agricultural row crops most similar to tillage/agricultural land classification, which does not exhibit the characteristics of a low -impact development. By utilizing the native grass seed mix below the panels, the existing tillage/agricultural land areas will be changed to a heavy meadow land classification that reduces peak flow rates and manages stormwater in line with the historic conditions of the site. The site design promotes conservation design at both the watershed and site levels, with the goal of replicating the native hydrologic characteristics of the sub -watersheds, creating natural ground coverage, and minimizing proposed grading and Blue Spruce Solar — Weld County, CO August 2023 Page 4 Kimley >) Horn compaction. The site will not receive offsite drainage and offsite drainage patterns will remain the same as historic conditions. Stormwater Runoff The stormwater runoff for existing and proposed conditions is calculated utilizing the Rational Method. The 100 -year, 1 -hour storm event was analyzed for pre and post -construction drainage basins. The flow path for the basins can be seen in Exhibits 4 & 5. The time of concentration to the point of accumulation was calculated using MHFD equations and can be found in Exhibit 6. The Runoff Coefficients are also included in Exhibit 6. The precipitation data used for the 100 - year, 1 -hour storm event is based on NOAA rainfall data from the project site (Exhibit 3). A summary of the rational calculation findings is shown in the table below. Existing Proposed Area 96.86 ac 96.86 ac Imperviousness 2.0 % 8.0 % Q1oo 126.1 cfs 116.3 cfs 1.4. Stormwater Management A study published in the Journal of Hydrologic Engineering researched the hydrologic impacts of utility scale solar generating facilities. The study utilized a model to simulate runoff from pre -and post -solar panel conditions. The study concluded that the solar panels themselves have little to no impact on runoff volumes or rates. Rainfall losses, most notably infiltration, are not impacted by the solar panels. Rainfall that falls directly on a solar panel runs to the pervious areas around and under the surrounding panels. Refer to Exhibit 7 for the study published in the Journal of Hydrologic Engineering. Under developed conditions, runoff will follow existing drainage patterns and will reduce peak flows (decreases from 126.1 cfs to 116.3 cfs in the 100-year,1-hour storm event). 2. CONCLUSION The following list summarizes key components of the Project and findings related to land disturbance and storm water impacts. • Installation of the solar facility will temporarily disturb the ground surface within the 96.86 acre -project area, but won't require clearing and grubbing of vegetation or grading, except for concrete equipment pads and gravel access drive installations. • The areas considered impervious or semi -impervious are a large portion of the project area, however the semi -impervious areas under the solar panels (modeled as 25% impervious) represent 21% of the total site area, and by implementing low -maintenance grass seed mix underneath, the site will reduce peak flow rates from existing conditions. • Under existing conditions, the peak flow from the site area for the 100 yr — lhr storm event is 126.1 cfs. • Under developed conditions, the peak flow from the site area for the 100 yr — lhr storm event is 116.3 cfs. • Installation of the solar facility is not expected to impact existing drainage patterns or flow rates on or around the project site. Runoff water quality will not be impacted by the solar facility components. Blue Spruce Solar — Weld County, CO August 2023 Page 5 Kimley >) Horn • The project design will adequately protect public health, safety and general welfare and have no adverse effects on Weld County right-of-way or offsite properties. As noted above, a study published in the Journal of Hydrologic Engineering (Exhibit 7) researched the hydrologic impacts of utility scale solar generating facilities. The study utilized a model to simulate runoff from pre -development and post -development solar panel conditions. The study concluded that the solar panels themselves have little to no impact on runoff volumes or rates. Rainfall losses, most notably infiltration, are not impacted by the solar panels. Rainfall that falls directly on a solar panel runs to the pervious areas around and under the surrounding panels. Grading is proposed with minimal changes to the existing site drainage patterns and onsite access roads will be made of gravel. Based on the proposed improvements on the project site, the findings of the above referenced study, and the calculations included within this report, the site will reduce peak flows from the existing rates. Therefore, permanent stormwater detention and water quality facilities are not proposed with the project. We trust that the information provided is acceptable and complete for preliminary site plan review drainage report requirements. Please let us know if you have any questions or need additional information. KIMLEY-HORN LEY -HORN AND ASSOCIATES, INC. Adam Harrison, PE Project Manager Blue Spruce Solar — Weld County, CO August 2023 Page 6 Exhibit 1 — FEMA Firm Map National Flood Hazard Layer FIRMette FEMA Legend 104°38'23"W 40°18'44"N 104°37'46"W 40°18'16"N SLVEIJ) I:_ 0 250 500 1,000 1,500 08.12_ 1/20/2016 Not Printed T4N F 65W S23 2,000 Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 PROJECT AREA J saant Feet 1:6,000 SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V. A99 With BFE or Depth Zone AE, AO, AN, VE, AR Regulatory Floodway OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Future Conditions 1% Annual Chance Flood Hazard Area with Reduced Flood Risk due to Levee. See Notes. Zone X Area with Flood Risk due to Levee Zone D NO SCREEN Area of Minimal Flood Hazard zone x Effective LOM Rs Area of Undetermined Flood Hazard Zone D - Channel, Culvert, or Storm Sewer milli Levee, Dike, or Floodwall 20.2 Cross Sections with 1% Annual Chance 1765 Water Surface Elevation 8 - - - - Coastal Transect .� ,1 n Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary - - - Coastal Transect Baseline Profile Baseline Hydrographic Feature Digital Data Available No Digital Data Available Unmapped The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 4/28/2023 at 10:46 AM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Exhibit 2 — NRCS Report 40° 18' 42" N S 40° 18' 16" N S 104° 38' 32" W 104° 38' 32" W Hydrologic Soil Group —Weld County, Colorado, Southern Part 530500 530600 530700 530800 530900 Map Scale: 1:5,630 if printed on A landscape (11" x 8.5") sheet Meters 0 50 100 200 300 531000 531100 531200 Feet 0 250 500 1000 1500 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 531600 I I I 531300 531400 531500 531600 104° 37' 39" W 104° 37 39" W co Co 40° 18' 42" N 40° 18' 16" N ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 4/28/2023 Page 1 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part MAP LEGEND Area of Interest (AO!) Area of Interest (A01) ) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines 0 0 A A/D B B/D C C/D D Not rated or not available Soil Rating Points II O O O A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background ,; Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 21, Sep 1, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 8, 2021 Jun 12, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 4/28/2023 Page 2 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 4 Aquolls flooded and Aquepts, D 57.5 58.7% 50 Otero sandy loam, percent slopes 0 to 1 A 15.9 16.3% 70 Valent sand, percent slopes 3 to 9 A 19.9 20.3% 72 Vona percent loamy slopes sand, 0 to 3 A 1.5 1.5% 76 Vona sandy loam, percent slopes 1 to 3 A 3.2 3.3% Totals for Area of Interest 98.0 100.0% e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/28/2023 Page 3 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and CID). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, BID, or CID), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie -break Rule: Higher e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/28/2023 Page 4of4 Exhibit 3 — NOAA Rainfall Data NOAA Atlas 14, Volume 8, Version 2 Location name: La Salle, Colorado, USA* Latitude: 40.3066°, Longitude: -104.6379° Elevation: 4700.91 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES V 1 I LI1111 - �C S U+` 'MFq rp Or Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration 5 -min J 10 -min J 1 15 -min 30 -min 60 -min 2 -hr 3 -hr 6 -hr 12 -hr 24 -hr 2 -day 3 -day 4 -day 7 -day 10 -day 20 -day 30 -day 45 -day 60 -day Average recurrence interval (years) 0.242 (0.198-0.299) 0.355 (0.291-0.437) 0.433 (0.354-0.533) 0.580 (0.475-0.715) 0.720 (0.590-0.887) 0.859 (0.709-1.05) 0.941 (0.780-1.15) 1.09 (0.907-1.31) 1.27 (1.07-1.52) 1.51 (1.28-1.79) 1.73 (1.48-2.04) 1.90 (1.62-2.22) 2.02 (1.74-2.36) 2.30 (1.99-2.67) 2.55 (2.21-2.93) 3.25 (2.85-3.71) 3.82 (3.36-4.34) 0.293 (0.240-0.362) 0.429 (0.351-0.530) 0.523 (0.428-0.646) 0.700 (0.573-0.864) 0.856 (0.700-1.06) 1.01 (0.833-1.24) 1.10 [(0.906-1.33) 1.27 (1.06-1.53) 1.51 (1.26-1.80) 1.78 1.50-2.11) 2.06 (1.75-2.42) 2.22 1.90-2.60) 2.36 (2.02-2.75) 2.69 (2.32-3.11) 2.97 (2.58-3.43) 3.76 (3.29-4.29) 4.39 (3.86-4.99) 4.51 (3.98-5.09) 5.06 (4.48-5.70) 5.18 (4.57-5.85) 5.84 (5.17-6.58) 5 0.390 (0.318-0.483) 0.571 (0.466-0.708) 0.697 (0.568-0.863) 0.932 (0.759-1.15) 1.13 (0.920-1.40) 1.33 (1.09-1.63) 1.42 (1.17-1.74) 1.65 (1.37-2.00) 10 0.484 (0.392-0.603) 0.709 (0.574-0.882) 0.865 (0.700-1.08) 1.16 (0.936-1.44) 1.40 1.14-1.75) 1.65 1.35-2.04) 1.77 (1.45-2.17) 2.04 1.68-2.48) 1.95 1.63-2.34) 2.38 (1.97-2.87) 2.27 2.72 (1.91-2.70) (2.28-3.26) 2.62 II 3.13 2.23-3.10)JL (2.64-3.71) 2.80 I 3.30 2.38-3.28) _ [(2.80-3.90) 2.94 3.45 (2.51-3.43)J (2.93-4.05) 3.34 if 3.89 (2.87-3.87) IL (3.33-4.54) 3.68 (3.18-4.25) 4.58 (3.98-5.24) 5.30 (4.64-6.05) 6.24 (5.49-7.08) 7.06 (6.22-7.97) 4.27 (3.67-4.96) 5.24 (4.54-6.03) 25 0.633 (0.500-0.845) 0.927 (0.732-1.24) 1.13 (0.892-1.51) 1.52 (1.20-2.03) 1.85 (1.47-2.49) 2.19 (1.76-2.93) 2.36 (1.90-3.14) 2.68 (2.17-3.52) 3.05 (2.47-3.92) 3.43 (2.79-4.34) 3.87 (3.16-4.81) 4.05 (3.32-5.01) J 4.20 (3.46-5.17) 4.68 J (3.86-5.68) 5.09 (4.21-6.12) 6.04 (5.25-6.92) 7.09 (6.19-8.08) 8.02 (7.03-9.10) 6.14 (5.11-7.28) 7.03 (5.87-8.27) 8.21 (6.88-9.59) 9.28 (7.79-10.8) 50 0.763 (0.582-1.03) 1.12 (0.851-1.51) 1.36 (1.04-1.84) 1.83 (1.40-2.47) 2.26 (1.72-3.05) 2.68 (2.07-3.61) 100 0.907 (0.661-1.26) 1.33 (0.969-1.84) 1.62 (1.18-2.24) 2.18 (1.59-3.02) 2.71 (1.98-3.77) 3.24 (2.39-4.47) 2.89 (2.25-3.88) 3.26 (2.55-4.31) 3.63 (2.85-4.72) 4.02 (3.18-5.15) 4.48 (3.55-5.64) 4.67 (3.72-5.85) 4.82 (3.86-6.01) 5.31 (4.26-6.54) 5.73 (4.62-7.00) 6.83 (5.54-8.23) 7.77 (6.33-9.29) (7.9.04 40-10.7) 10.2 (8.37-12.0) 3.50 (2.60-4.82) 3.91 (2.93-5.31) 4.28 (3.22-5.71) 4.67 (3.54-6.15) 5.12 (3.90-6.63) 5.32 (4.07-6.84) 5.47 (4.21-7.01) 5.95 (4.60-7.53) 6.38 (4.95-8.00) 7.50 (5.87-9.28) 8.49 (6.67-10.4) 9.83 (7.76-12.0) 11.1 (8.75-13.4) 200 1.07 (0.739-1.52) 1.56 1.08-2.23) 1.91 (1.32-2.72) 2.57 (1.78-3.67) 3.22 (2.23-4.61) 3.86 (2.71-5.49) 4.20 (2.96-5.94) 4.65 (3.31-6.50) 500 1000 1.30 (0.857-1.91) 1.90 (1.25-2.80) 2.32 (1.53-3.41) 3.14 (2.07-4.61) 1.49 (0.947-2.20) 2.18 (1.39-3.23) 2.66 (1.69-3.93) 3.60 (2.29-5.32) 3.97 2.62-5.84) 4.80 (3.20-7.01) 4.59 (2.92-6.78) 5.58 (3.58-8.15) 5.24 (3.52-7.61) 5.75 (3.90-8.26) 4.99 I 6.0252) 3.57-6.85)J 5.38 (3.89-7.30) 5.81 (4.22-7.75) 6.01 (4.39-7.97)J 6.17 (4.53-8.14) 6.63 (4.89-8.64) 7.04 (5.21-9.09) 8.17 (6.11-10.4)]L 9.20 (6.90-11.6)J 10.6 (8.00-13.3) 11.9 (8.99-14.8) 6.40 (4.42-8.94) 6.77 (4.70-9.31) C 6.98 (4.88-9.54) 7.14 (5.01-9.71) 7.55 (5.33-10.1) 7.92 (5.62-10.5) 9.05 (6.48-11.9) 10.1 (7.27-13.2) 11.6 (8.37-14.9) 12.9 (9.36-16.6) 6.11 (3.94-8.88) 6.67 (4.35-9.58) 6.87 (4.53-9.78) 7.24 (4.82-10.2) 7.54 (5.07-10.5) 7.76 (5.25-10.7) 7.92 (5.38-10.9) 8.27 (5.67-11.3) 8.59 (5.93-11.6) 9.70 (6.76-13.0) 10.8 (7.55-14.3) 12.2 (8.65-16.2) 13.6 (9.65-17.9) Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical PDS-based depth -duration -frequency (DDF) curves Latitude: 403066°r Longitude: -104.6379° Precipitation depth (in) 14 12 10 14 12 10 1 a 1 i 1 1 1 1 I I I 1 1 1 I I I 1 I I I I e e I 1 I 1 I I I I 1 a a 1 I 1 1 1 1 1 1 1 a 1 1 a a I 1 I 1 I I I I I I 1 1 1 1 I I I I 1 a a a a a a a a 1 1 1 1 1 Y a .... . .1. • as . . Pr . . . . . L . . _ . . ,.I _ . .I .. _ .a .. _ . ../1 . _ ..1_ _ . . . L. . . . .. I. . _ .. I. a a e I 1 4 Y a • • . • a a a a • a • • a a a I 1 I I 1 1 1 a I 1 I 1 1 1 I I • • I I • • • I P I P I I • • 1 1 1 1 1 1 1 a 1 1 a 1 a a 1 1 V I I I I I e t e a IF I I a I a a 1 a a a a 1 a a a a a a a a a a s i a a i i i a 1 • a a if ! a 1 1 I I I I 1 1 t t t . 1 a I p . I vl al a 1 1 1 1 1 a e e e I I I I e 1 e e e I e I I I • • • 1t I I I I 1 1 1 I I 1 a I i I I / 1 1 e g a I a e e • • e e -- . —— t 1 I I I I I I a i -_ _ 1• — • I I a 1 I a a a a 1 ....-.a t Y Y- e a . Y 1 1 a 1 a � a a e e 1 a 1 1 a a I ....rears— I I I 5 • I Y • - 'J • • • - - i 1 1 a 1 1 Y 1 - 1 1 1 a a a 1 I a I 1 a I a t - i { • I I 1 ! 1 f e I I I I I I I t ! t ! I i r - — — — — — — — — — • t •. _ — — — _ _ _ _ Y— — 1 — '. — — I— — —I•_ .. — — I 1 1 I 1 a i - 1 1 a i 1 a e e e e I I a a I • e Y 1 1 a a 1 a e e T - ! a�fi II ! ! e e e a 1 I C c e t'•J 1 _ LA 5 10 25 50 100 200 NOM Atlas 14, Volume 8, Version 2 C 1•D 1 1 Duration :- = .�•i 1 i3 111 a I to I I N ICIrzi Average recurrence interval (years) ro Co rp V V V t 6 u1 6 N f #Le 500 1000 Created {GMT): Mon Feb 6 20:20:13 2023 Back to Top Maps & aerials Small scale terrain Average recurrence interval (years) 1 2 5' 10 25 50 100 200 500 1 000 Duration 5-mp — 2 -day 10-mon — 3 -day 15' -min — 4 -day 30 -min — 7 -day 6 Din - 10 -day 2 -hr — 2.0 -day 34',r — 30 -day. 5 -hr — 45 -day .112 -ht 50 -day 24 -hr Nastesiesturiset Lmna'f?'1 R e c ervo l,r -, SE 3km 2mi EASTON VA L El VIEW avhc: ARPO,R Elba - _; A Large scale terrain Large scale map S Large scale aerial Cheyenne - Ireeley ■I L'? ngm ln Boulder 100km 60mi -11 er Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?: HDSC.Questions@noaa.gov Disclaimer Exhibit 4 — Pre -Development Drainage Area Map \\IX, c ``.,i•oo2as '300_RWIFlitch\.<na 9wrlr - 4.v\G ) f.rtiouI.\114 - 6a*sIac WAD a*i� is J.c. 0/JOIMJ! t5{ AY a l ..a ell.. a t . uenl•a s1 air tuui to a alb .• r antra r. •.e e. wv c r fl .i i4. 4 real asa Y r .l. M...r... Jla As Ka at- .r. ant. sat a It s - ak .s.0 — cli \Q A :3,_ \ ) i N, I AIII -di i 15k, it \ ,--, A I r e 1 T ---.71 / / 1 1, it, r IS cv I / ik L'-e>'—gai; aft — — - - i ENNIO -s ri fi -�- s t�-_ -s a-.‘ fee 4 e--- soo .c.„ I S /t r, S M A h ♦ — _ • � r Ct 1 r3 I ®" k . rs r C• )* • 4 cti tit g i A 4.43 alt. E `� • ,K I / se 1 I tJ • V • • BLUE SPRUCE - CLOUDBREAK WELD COUNTY, COLORADO USE BY SPECIAL REVIEW PRE -CONSTRUCTION DRAINAGE MAP 81 4 Kimley* Horn C) 2023 [Stir --a. no ASTAOARS v� taw stet'. su I •4CO Ore. Catarina EOM (.10.1) 710 2.100 CLOUD\RIAt NC Exhibit 5 — Post -Development Drainage Area Map $-> -wrest,,\-rs.:tie: + g= tw. riu•:1 P..tSa'iMarw Newit e - a..IN a rttny s ;redact dact tte_rocl.t.."t�.:i'' 'f . m •...1 JW/. .�. 11 a.. W l*1al—• Wla—+W1,..d�._.— a hoc. t �ro2] t !/ AY W Y IWLr as5.W1...,.�.a . W ..1IS.• .WG1'1 Y..fa.. W — . - 7, of t T 1 2 A -a NC MI. aro • A- 1 1 I • is 4.4IMM-s a 7 I • SS a re' t r a ain re In L a �, 11 �; W • I II 1 1 - I I _ 1\ I I to • -,1 t j I I I I I i I I I I N r t aie N r^� OITA rtr ci iti . aMMIS • I, - I _ ) _ 1O I r" I, _ ,1 I, , It _ Saw ,I 1 a' 4 4 H!Ji:j —T—'H + t a _ I! lira s-i F — _ r / CO I , _ • • __ • J • 1 { l' 1 • J a a a a .IS r 1' asint \ r• • VS • I 1 _ 4 I t I 4 i Ii rJ I s -4__ I I I 4 a 1 v a s- to A F i M 6 S t1 vt p y : [ s A 2 I- I S F 1t 0 C k r I I, I I I rn m Z 0 BLUE SPRUCE - CLOUDBREAK WELD COUNTY. COLORADO USE BY SPECIAL REVIEW POST -CONSTRUCTION DRAINAGE MAP Kimley>»Horn 7G23 (Wt1 . - .1a ASS0OA1n. .IC 1/5 trw 514'. • • CO u.....,, C. n.. 00202 003) no- »00 AC 0110101,4 DA7i aP% Exhibit 6 — Hydrologic Calculations & Detention/WQCV Calculations Kimley PROJECT PROJECT CALCULATED CHECKED >>> NAME NUMBER- BY BY Horn RUNOFF COEFFICIENTS Weld 196664000 .ICI I All! County - Cloudbrcak - IMPERVIOUS -131uc STANDARD Spruce FORM CALCULATION SF -1 - PRE -CONSTRUCTION 8/30/2023 TYPE 1) SOIL VEGETATED BUILDING FUTURE PAVED GRAVEL OPEN SPACE ROOF COMMERCIAL LAND USA: AREA AREA AREA AREA 2 -YEAR COEFF 0.x 3 0.01 0.01 0.74 0.69 5 -YEAR COF.FF 0.84 0.16 0.16 0/6 0.72 100 -YEAR COEFF 0.89 0.51 ) ) 51 u ) x5 0.83 IMPERVIOUS P.'. 100% 2% 2% `N)% M5% DESK iN BASIN DESIGN PAVED AREA GRAVEI AREA VEGETATED OPEN SPACE AREA BUILDING RO(.N. AREA FUTURE t.(. )MMF.RCIAL AREA TUTAI AREA. i t 0 10o, in t POINT (_AC) (AC) (AC) (AC) (AC) _ (AC) On -Site Basins PRE -DA -4)1 I 302 3.02 0.01 016 'i51 2! - PRE -DA -O2 2 3.23 3.23 0.01 0 16 0 51 2.0% PRE -DA -03 3 13.25 13.25 0.01 0 16 0 51 2.0% PRE -DA -04 4 0.41 15.18 15.59 0.01 0.16 0 51 2.0% PRE -DA -05 5 0.19 9.05 9.24 0.01 0.16 0 51 2 0% PRE -DA -06 6 0.15 2.86 3.01 0.01 0.16 0.51 2.0% PRI:-DA-07 7 1.92 1.92 0.01 0.16 0.51 2.0% I'RE-IM-OS 8 n 24 4.54 4.82 0.01 0.16 0.51 2.0% PRE -DA -09 9 614 6.14 0.01 0.16 0.51 2.0% PRE -DA -10 10 1.1.06 7.78 7.84 0.01 0.16 0.51 2.0% PRE -DA -11 11 1.61 1.61 0.01 0.16 0.51 2.0% PRE -1)A-12 12 0.06 2.01 2.07 0.01 0.16 0.51 2.0% PRE -DA -13 13 0.78 3.54 4.32 0.01 0.16 0.51 2.0% PRE -DA -14 14 0.W ; 17 3.21 001 0.16 051 20% PRE -DA -15 15 _' 50 2._)) 001 0.16 051 2.0% PRE: -DA -16 16 0.02 S 09 5.111 0.01 0.16 0 51 2.0% PRE -DA -17 17 0 77 II.'- 0.01 0.16 0 51 2 0% PRE -DA- I S 18 0.01 3.51 3.3i 0.01 0.16 0 51 2 0% PRE -DA -19 19 1.00 )" I MI 0 01 0.16 0 51 2.0% PRE -DA -20 20 0.15 4.56 4.- 1 0.01 0.16 0 51 2.0% BASIN SUBTOTAL 0.00 2.15 94.70 0.00 0.00 '►r,.S6 (1 01 0 16 O 51 2.0% 0"%o 2% 98% 0% 11% 100% Kimley>>> Horn STANDARD FORM SF -2 TIME OF CONCENTRATION - PRE -CONSTRUCTION PRO. ECT NAME: Weld County - Cloudbreak - Blue Spruce DATE: 8/30/2023 PROJECT NUMBER: CALCULATED CHECKED BY: BY: 196664000 JCH AJH FINAL SUB -BASIN INITIAL TRAVEL TIME Tc CHECK DATA (Ti) Tc (URBANIZED BASINS) TIME (T;) DESIGN AREA C5 (3) LENGTH (4) Ft SLOPE % (5) Ti Min. LENGTH SLOPE % (8) C, (9) Land (10) Surface Tt Min. COMP. (13) tc TOTAL TOTAL TOTAL Min. (17) Tc Min. C2 C5 C100 VEL fps (11) Ac (2) Ft. (7) LENGTH (14) SLOPE (15) IMP. (16) BASIN (1) (6) (12) On -Site Basins PRE -DA -01 3.021 0.16 498 1.1% 37.6 Tillage/Field 37.6 498 1.1% 2% NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 37.6 0.01 0.16 0.51 PRE -DA -02 3.233 0.16 500 0.6% 46.0 96 0.1% 5.0 Tillage/Field 0.1 12.9 58.9 596 0.5% 2% 58.9 0.01 0.16 0.51 PRE -DA -03 13.247 0.16 500 0.5% 49.2 1,067 0.2% 5.0 Tillage/Field 0.2 74.2 123.4 1567 0.3% 2% 123.4 0.01 0.16 0.51 404.9 0.01 0.16 0.51 PRE -DA -04 15.587 0.16 500 0.8% 42.2 1,124 0.0% 5.0 Tillage/Field 0.1 362.7 404.9 1624 0.2% 2% PRE -DA -05 9.241 0.16 500 1.6% 33.0 240 0.4% 5.0 Tillage/Field 0.3 12.2 45.1 740 1.2% 2% 45.1 0.01 0.16 0.51 PRE -DA -06 3.013 0.16 466 1.5% 32.8 Tillage/Field 32.8 466 1.5% 2% 32.8 0.01 0.16 0.51 PRE -DA -07 1.918 0.16 466 1.0% 37.2 Tillae/Field 37.2 466 1.0% 2% 37.2 0.01 0.16 0.51 PRE -DA -08 4.823 0.16 441 0.7% 41.1 Tillage/Field 41.1 441 0.7% 2% 41.1 0.01 0.16 0.51 PRE -DA -09 6.137 0.16 500 0.5% 47.2 204 0.0% 5.0 Tillage/Field 0.1 34.3 81.5 704 0.4% 2% 81.5 0.01 0.16 0.51 PRE -DA -10 7.840 0.16 500 0.5% 47.4 247 0.2% 5.0 Tillage/Field 0.2 17.8 65.1 747 0.4% 2% 65.1 0.01 0.16 0.51 PRE -DA -11 1.605 0.16 433 0.6% 42.6 Tillage/Field 42.6 433 0.6% 2% 42.6 0.01 0.16 0.51 36.7 0.01 0.16 0.51 PRE -DA -12 2.070 0.16 211 0.3% 36.7 Tillage/Field 36.7 211 0.3% 2% PRE -DA -13 4.321 0.16 500 0.6% 46.6 217 0.2% 5.0 Tillage/Field 0.2 15.7 62.4 717 0.5% 2% 62.4 0.01 0.16 0.51 PRE -DA -14 3.214 0.16 500 1.2% 36.4 114 0.5% 5.0 Tillae/Field 0.3 5.5 41.9 614 1.1% 2% 41.9 0.01 0.16 0.51 PRE -DA -15 2.496 0.16 293 0.2% 55.5 Tillage/Field 55.5 293 0.2% 2% 55.5 0.01 0.16 0.51 PRE -DA -16 5.101 0.16 500 1.2% 36.4 166 0.8% 5.0 Tillage/Field 0.5 6.1 42.6 666 1.1% 2% 42.6 0.01 0.16 0.51 PRE -DA -17 0.774 0.16 261 1.2% 25.9 Tillage/Field 25.9 261 1.2% 2% 25.9 0.01 0.16 0.51 PRE -DA -18 3.512 0.16 500 1.0% 38.6 361 0.3% 5.0 Tillage/Field 0.3 22.4 61.0 861 0.7% 2% 61.0 0.01 0.16 0.51 PRE -DA -19 0.996 0.16 321 0.9% 31.9 Tillage/Field 31.9 321 0.9% 2% 31.9 0.01 0.16 0.51 PRE -DA -20 4.708 0.16 484 0.7% 42.4 Tillage/Field 42.4 484 0.7% 2% 42.4 0.01 0.16 0.51 'W �t 4 0,39501_1 _ . 2 �� s. � _ y � * 1�x ��-�sy f� 7� ' 6�f 1 'fy Y}, { �d lj N rrppA��+� s� .'lip , ��( 14i + y )Y. J, STANDARD FORM SF -3 Kimley>>> Horn STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT - PRE -CONSTRUCTION PRO.I F ET NAME: Weld County - Cloudbreak - Blue Spruce DATE' 8/30/2023 PRO.IF,CT NUMBER: 196664000 P1 (1 -Hour Rainfall) = 2.71 CALCULATED CHECKED BY: BY: JCH ASH REMARKS TRAVEL TIME DIRECT RUNOFF TOTAL RUNOFF STREET PIPE (u!ui) aj IGN VV(cfs I a^ GT] rt) it a,-,w•� ©4 © �,-. 64 gw 4e^ c c Is 4 ^ v� ~ a )V` o�.4t •- �� 1 )E a o 0 OO � w ozcA .e� Il cl) A A P74 CID (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) On -Site Basins 1 PRE -DA -01 3.02 0.51 37.58 1.54 3.71 5.72 i 2 PRE -DA -02 3.23 0.51 58.88 1.65 2.77 4.57 3 PRE -DA -03 13.25 0.51 123.38 6.76 1.65 11.15 4 PRE -DA -04 15.59 0.51 404.90 7.95 0.68 5.38 5 PRE -DA -05 9.24 0.51 45.13 4.71 3.30 15.57 6 PRE -DA -06 3.01 0.51 32.85 1.54 4.03 6.19 7 PRE -DA -07 1.92 0.51 37.17 0.98 3.74 3.65 8 PRE -DA -08 4.82 0.51 41.10 2.46 3.51 8.63 9 PRE -DA -09 6.14 0.51 81.51 3.13 2.22 6.94 10 PRE -DA -10 7.84 0.51 65.14 4.00 2.59 10.36 11 PRE -DA -11 1.61 0.51 42.57 0.82 3.43 2.81 12 PRE -DA -12 2.07 0.51 36.69 1.06 3.77 3.97 13 PRE -DA -13 4.32 0.51 62.35 2.20 2.67 5.88 14 PRE -DA -14 3.21 0.51 41.93 1.64 3.46 5.68 15 PRE -DA -15 2.50 0.51 55.50 1.27 2.89 3.67 16 PRE -DA -16 5.10 0.51 42.57 2.60 3.43 8.92 17 PRE -DA -17 0.77 0.51 25.92 0.39 4.63 1.83 18 PRE -DA -18 3.51 0.51 61.03 1.79 2.71 4.85 19 PRE -DA -19 1.00 0.51 31.88 0.51 4.10 2.08 20 PRE -DA -20 4.71 0.51 42.44 2.40 3.44 8.25 Total 96.86 126.11 Kimley>>>Horn STANDARD FORM SF -1 RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION - POST -CONSTRUCTION PROJECT NAME: Weld County - Cloudbreak - Blue Spruce 8/30/2023 PROJECT NUMBER: CALCULATED 196664000 BY: JCH CHECKED BY: AJH TYPE D SOIL VEGETATED FUTURE PAVED GRAVEL OPEN SPACE SOLAR PANEL COMMERCIAL LAND USE: AREA AREA AREA AREA AREA 2 -YEAR COEFF. 0.83 0.30 0.01 0.18 0.69 5 -YEAR COEFF. 0.90 0.35 0.16 0.28 0.72 100 -YEAR COEFF. 0.96 0.58 0.51 0.56 0.83 IMPERVIOUS % 100% 40% 2% 25% 85% DESIGN BASIN VEGETATED FUTURE Cc(2) Cc(5) Cc(100) Imp % PAVED GRAVEL OPEN SPACE SOLAR PANEL COMMERCIAL TOTAL DESIGN AREA AREA AREA AREA AREA AREA POINT (AC) (AC) (AC) (AC) (AC) (AC) On -Site Basins POST -DA -01 1 0.14 2.57 0.30 3.02 0.04 0.18 0.52 6.1°%o POST -DA -02 2 2.67 0.56 3.23 0.04 0.18 0.52 6.0% POST -DA -03 3 0.06 0.56 5.97 6.65 13.25 0.11 0.23 0.54 15.6% POST -DA -04 4 0.06 0.24 12.27 3.01 15.59 0.05 0.19 0.52 7.4% POST -DA -05 5 0.21 8.91 0.11 9.24 0.02 0.17 0.51 3.2°%0 POST -DA -06 6 0.15 2.86 3.01 0.02 0.17 0.51 3.9% POST -DA -07 7 1.92 1.92 0.01 0.16 0.51 2.0% POST -DA -08 8 0.23 3.75 0.84 4.82 0.05 0.19 0.52 7.8% POST -DA -09 9 4.61 1.52 6.14 0.05 0.19 0.52 7.7°%0 POST -DA -10 10 0.03 0.18 7.33 0.29 7.84 0.03 0.17 0.52 4.1% POST -DA -11 11 1.61 1.61 0.01 0.16 0.51 2.0% POST -DA -12 12 0.06 1.92 0.09 2.07 0.03 0.17 0.51 4.1% POST -DA -13 13 0.03 0.23 1.86 2.20 4.32 0.12 0.24 0.54 16.5% POST -DA -14 14 0.03 0.08 2.28 0.83 3.21 0.07 0.20 0.53 9.8% POST -DA -15 15 2.04 0.45 2.50 0.04 0.18 0.52 6.2% POST -DA -16 16 0.02 3.71 1.38 5.10 0.06 0.19 0.52 8.3% POST -DA -17 17 0.70 0.07 0.77 0.03 0.17 0.51 4.1°%0 POST -DA -18 18 0.01 3.12 0.39 3.51 0.03 0.17 0.52 4.6% POST -DA -19 19 0.96 0.03 1.00 0.02 0.16 0.51 2.7% POST -DA -20 20 0.24 2.62 1.86 4.71 0.09 0.22 0.53 13.0% BASIN SUBTOTAL 0.22 2.35 73.69 20.59 0.00 96.86 0.05 0.19 0.52 8.0°%0 0% 2% 76% 21% 0% 100% Kimley>>> Horn STANDARD FORM SF -2 TIME OF CONCENTRATION - POST -CONSTRUCTION PROJECT NAME: PROJECT NUMBER: CALCULATED Weld County 196664000 BY: JCH - Cloudbreak - Blue Spruce DATE: 8/30/2023 CHECKED BY: AJH INITIAL TRAVEL TIME Te CHECK FINAL Tc SUB -BASIN DATA (Ti) (URBANIZED BASINS) TIME (Ti) DESIGN BASIN AREA Ac (2) CS (3) SLOPE Ti Min. (6) SLOPE % (8) C, (9) Land Surface Min. (12) Tt COMP. (13) to TOTAL TOTAL TOTAL Min. (17) Tc Min. C2 C5 i C100 LENGTH LENGTH VEL Ft (4) % (5) Ft. (7) (10) fps (11) SLOPE (15) IMP. LENGTH (1) (14) (16) On -Site Basins POST -DA -01 3.021 0.18 498 1.1% 36.7 Heavy Meadow 36.7 498 1.1% 6% 33.1 33.1 0.04 0.18 0.52 POST -DA -02 3.233 0.18 500 0.6% 45.0 96 0.1% 2.5 Heavy Meadow 0.1 25.8 70.7 596 0.5% 6% NA 70.7 0.04 0.18 0.52 POST -DA -03 13.246 0.23 500 0.5% 45.4 1,067 0.2% 2.5 Heavy Meadow 0.1 148.5 193.8 1567 0.3% 16% NA 193.8 0.11 0.23 0.54 POST -DA -04 15.587 0.19 500 0.8% 40.9 1,124 0.0% 2.5 Heavy Meadow 0.0 725.4 766.3 1624 0.2% 7% NA 766.3 0.05 0.19 0.52 POST -DA -05 9.241 0.17 500 1.6% 32.8 240 0.4% 2.5 Heavy Meadow 0.2 24.3 57.1 740 1.2% 3% NA 57.1 0.02 0.17 0.51 POST -DA -06 3.013 0.17 466 1.5% 32.5 Heavy Meadow 32.5 466 1.5% 4% NA 32.5 0.02 0.17 0.51 POST -DA -07 1.918 0.16 466 1.0% 37.2 Heavy Meadow 37.2 466 1.0% 2% NA 37.2 0.01 0.16 0.51 POST -DA -08 4.823 0.19 441 0.7% 39.8 Heavy Meadow 39.8 441 0.7% 8% NA 39.8 0.05 0.19 0.52 POST -DA -09 6.137 0.19 500 0.5% 45.7 204 0.0% 2.5 Heavy Meadow 0.0 68.6 114.3 704 0.4% 8% NA 114.3 0.05 0.19 0.52 POST -DA -10 7.839 0.17 500 0.5% 46.8 247 0.2% 2.5 Heavy Meadow 0.1 35.5 82.3 747 0.4% 4% NA 82.3 0.03 0.17 0.52 POST -DA -11 1.605 0.16 433 0.6% 42.6 Heavy Meadow 42.6 433 0.6% 2% NA 42.6 0.01 0.16 0.51 POST -DA -12 2.070 0.17 211 0.3% 36.3 Heavy Meadow 36.3 211 0.3% 4% NA 36.3 0.03 0.17 0.51 POST -DA -13 4.320 0.24 500 0.6% 42.8 217 0.2% 2.5 Heavy Meadow 0.1 31.4 74.3 717 0.5% 16% NA 74.3 0.12 0.24 0.54 POST -DA -14 3.214 0.20 500 1.2% 34.7 114 0.5% 2.5 Heavy Meadow 0.2 11.1 45.8 614 1.1% 10% NA 45.8 0.07 0.20 0.53 POST -DA -15 2.496 0.18 293 0.2% 54.2 Heavy Meadow 54.2 293 0.2% 6% NA 54.2 0.04 0.18 0.52 POST -DA -16 5.101 0.19 500 1.2% 35.2 166 0.8% 2.5 Heavy Meadow 0.2 12.2 47.4 666 1.1% 8% NA 47.4 0.06 0.19 0.52 POST -DA -17 0.774 0.17 261 1.2% 25.6 Heavy Meadow 25.6 261 1.2% 4% NA 25.6 0.03 0.17 0.51 POST -DA -18 3.512 0.17 500 1.0% 38.1 361 0.3% 2.5 Heavy Meadow 0.1 44.8 82.9 861 0.7% 5% NA 82.9 0.03 0.17 0.52 POST -DA -19 0.996 0.16 321 0.9% 31.8 Heavy Meadow 31.8 321 0.9% 3% NA 31.8 0.02 0.16 0.51 POST -DA -20 4.710 0.22 484 0.7% 39.9 Heavy Meadow 39.9 484 0.7% 13% NA 39.9 0.09 0.22 0.53 LI 4 03 95(L 1 — Cc _ 1 -. :1 3 600K VS 6'01, 60(141 + 9 7 STANDARD FORM SF -3 Kimle >>> Horn STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT - POST -CONSTRUCTION PROJECT NAME: Weld County - Cloudbreak - Blue Spruce DATE: 8/30/2023 PROJECT NUMBER: 196664000 P1 (1 -Hour Rainfall) = 2.71 CALCULATED BY: JCH CHECKED BY: AJH DIRECT RUNOFF TOTAL RUNOFF STREET TRAVEL TIME REMARKS PIPE tc (min) C*A(ac) o p.� tc(ma: a o ♦^, r-, . E v )` om co pa CY w w CA V) CE CA ....- a E• W� W' .� `- �, D-4 ��, Gov .5 W VD al g (1) I (2) I (3) I (4) I (5) I (6) I (7) I (8) I (9) 1(10)1(11) 1(12)1 (13) 1(14)1(15)1(16) (17) I (18) I (19) 1(20)1(21) (22) On -Site Basins 1 POST -DA -01 3.02 0.52 33.10 1.57 4.01 6.28 2 POST -DA -02 3.23 0.52 70.74 1.68 2.45 4.11 3 POST -DA -03 13.25 0.54 193.85 7.16 1.18 8.46 4 POST -DA -04 15.59 0.52 766.31 8.14 0.41 3.37 5 POST -DA -05 9.24 0.51 57.10 4.73 2.83 13.40 6 POST -DA -06 3.01 0.51 32.52 1.55 4.05 6.27 7 POST -DA -07 1.92 0.51 37.17 0.98 3.74 3.65 8 POST -DA -08 4.82 0.52 39.79 2.52 3.58 9.01 9 POST -DA -09 6.14 0.52 114.32 3.21 1.74 5.59 10 POST -DA -10 7.84 0.52 82.29 4.04 2.20 8.90 11 POST -DA -11 1.61 0.51 42.57 0.82 3.43 2.81 12 POST -DA -12 2.07 0.51 36.28 1.06 3.79 4.03 13 POST -DA -13 4.32 0.54 74.26 2.34 2.37 5.55 14 POST -DA -14 3.21 0.53 45.83 1.70 3.27 5.56 15 POST -DA -15 2.50 0.52 54.21 1.30 2.93 3.80 16 POST -DA -16 5.10 0.52 47.41 2.67 3.20 8.55 17 POST -DA -17 0.77 0.51 25.61 0.40 4.66 1.86 18 POST -DA -18 3.51 0.52 82.86 1.81 2.19 3.97 19 POST -DA -19 1.00 0.51 31.75 0.51 4.11 2.09 20 POST -DA -20 4.71 0.53 39.88 2.51 3.57 8.98 Total 96.86 116.25 Exhibit 7 — Hydrologic Response of Solar Farms Hydrologic Response of Solar Farms Lauren M. Cook, S.M.ASCE1; and Richard H. McCuen, M.ASCE2 Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. Abstract: Because of the benefits of solar energy, the number of solar farms is increasing; however, their hydrologic impacts have not been studied. The goal of this study was to determine the hydrologic effects of solar farms and examine whether or not storm -water management is needed to control runoff volumes and rates. A model of a solar farm was used to simulate runoff for two conditions: the pre- and postpaneled conditions. Using sensitivity analyses, modeling showed that the solar panels themselves did not have a significant effect on the runoff volumes, peaks, or times to peak. However, if the ground cover under the panels is gravel or bare ground, owing to design decisions or lack of maintenance, the peak discharge may increase significantly with storm -water management needed. In addition, the kinetic energy of the flow that drains from the panels was found to be greater than that of the rainfall, which could cause erosion at the base of the panels. Thus, it is recommended that the grass beneath the panels be well maintained or that a buffer strip be placed after the most downgradient row of panels. This study, along with design recommendations, can be used as a guide for the future design of solar farms. DOE 10.1061/(ASCE) HE.1943-5584.0000530. © 2013 American Society of Civil Engineers. CE Database subject headings: Hydrology; Land use; Solar power; Floods; Surface water; Runoff; Stormwater management. Author keywords: Hydrology; Land use change; Solar energy; Flooding; Surface water runoff; Storm -water management. Introduction Storm -water management practices are generally implemented to reverse the effects of land -cover changes that cause increases in volumes and rates of runoff. This is a concern posed for new types of land -cover change such as the solar farm. Solar energy is a re- newable energy source that is expected to increase in importance in the near future. Because solar farms require considerable land, it is necessary to understand the design of solar farms and their potential effect on erosion rates and storm runoff, especially the impact on offsite properties and receiving streams. These farms can vary in size from 8 ha (20 acres) in residential areas to 250 ha (600 acres) in areas where land is abundant. The solar panels are impervious to rain water; however, they are mounted on metal rods and placed over pervious land. In some cases, the area below the panel is paved or covered with gravel. Service roads are generally located between rows of panels. Altl- hough some panels are stationary, others are designed to move so that the angle of the panel varies with the angle of the sun. The angle can range, depending on the latitude, from 22° during the summer months to 74° during the winter months. In addition, the angle and direction can also change throughout the day. The issue posed is whether or not these rows of impervious panels will change the runoff characteristics of the site, specifically increase runoff volumes or peak discharge rates. If the increases are hydro- logically significant, storm -water management facilities may be needed. Additionally, it is possible that the velocity of water 1Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Maryland, College Park, MD 20742-3021. 2The Ben Dyer Professor, Dept. of Civil and Environmental Engineer- ing, Univ. of Maryland, College Park, MD 20742-3021 (corresponding author). E-mail: rhmccuen@eng.umd.edu Note. This manuscript was submitted on August 12, 2010; approved on October 20, 2011; published online on October 24, 2011. Discussion period open until October 1, 2013; separate discussions must be submitted for individual papers. This paper is part of the Journal of Hydrologic Engi- neering, Vol. 18, No. 5, May 1, 2013. © ASCE, ISSN 1084-069912013/5- 536-541/$25.00. draining from the edge of the panels is sufficient to cause erosion of the soil below the panels, especially where the maintenance roadways are bare ground. The outcome of this study provides guidance for assessing the hydrologic effects of solar farms, which is important to those who plan, design, and install arrays of solar panels. Those who design solar farms may need to provide for storm -water management. This study investigated the hydrologic effects of solar farms, assessed whether or not storm -water management might be needed, and if the velocity of the runoff from the panels could be sufficient to cause erosion of the soil below the panels. Model Development Solar farms are generally designed to maximize the amount of en- ergy produced per unit of land area, while still allowing space for maintenance. The hydrologic response of solar farms is not usually considered in design. Typically, the panels will be arrayed in long rows with separations between the rows to allow for maintenance vehicles. To model a typical layout, a unit width of one panel was assumed, with the length of the downgradient strip depending on the size of the farm. For example, a solar farm with 30 rows of 200 panels each could be modeled as a strip of 30 panels with space between the panels for maintenance vehicles. Rainwater that drains from the upper panel onto the ground will flow over the land under the 29 panels on the downgradient strip. Depending on the land cover, infiltration losses would be expected as the runoff flows to the bottom of the slope. To determine the effects that the solar panels have on runoff characteristics, a model of a solar farm was developed. Runoff in the form of sheet flow without the addition of the solar panels served as the prepaneled condition. The paneled condition assumed a downgradient series of cells with one solar panel per ground cell. Each cell was separated into three sections: wet, dry, and spacer. The dry section is that portion directly underneath the solar panel, unexposed directly to the rainfall. As the angle of the panel from the horizontal increases, more of the rain will fall directly onto 536 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. the ground; this section of the cell is referred to as the wet section. The spacer section is the area between the rows of panels used by maintenance vehicles. Fig. 1 is an image of two solar panels and the spacer section allotted for maintenance vehicles. Fig. 2 is a sche- matic of the wet, dry, and spacer sections with their respective di- mensions. In Fig. 1, tracks from the vehicles are visible on what is modeled within as the spacer section. When the solar panel is hori- zontal, then the length longitudinal to the direction that runoff will occur is the length of the dry and wet sections combined. Runoff from a dry section drains onto the downgradient spacer section. Runoff from the spacer section flows to the wet section of the next downgradient cell. Water that drains from a solar panel falls directly onto the spacer section of that cell. The length of the spacer section is constant. During a storm event, the loss rate was assumed constant for the 24-h storm be- cause a wet antecedent condition was assumed. The lengths of the wet and dry sections changed depending on the angle of the solar panel. The total length of the wet and dry sections was set Fig. 1. Maintenance or "spacer" section between two rows of solar panels (photo by John E. Showler, reprinted with permission) Ld Direction of Flow Wet section Dry section Spacer section 5 m 3.5 m Fig. 2. Wet, dry, and spacer sections of a single cell with lengths Lw, Ls, and Ld with the solar panel covering the dry section equal to the length of one horizontal solar panel, which was as- sumed to be 3.5 m. When a solar panel is horizontal, the dry section length would equal 3.5 m and the wet section length would be zero. In the paneled condition, the dry section does not receive direct rainfall because the rain first falls onto the solar panel then drains onto the spacer section. However, the dry section does infiltrate some of the runoff that comes from the upgradient wet section. The wet section was modeled similar to the spacer section with rain falling directly onto the section and assuming a constant loss rate. For the presolar panel condition, the spacer and wet sections are modeled the same as in the paneled condition; however, the cell does not include a dry section. In the prepaneled condition, rain falls directly onto the entire cell. When modeling the prepaneled condition, all cells receive rainfall at the same rate and are subject to losses. All other conditions were assumed to remain the same such that the prepaneled and paneled conditions can be compared. Rainfall was modeled after an natural resources conservation service (NRCS) Type II Storm (McCuen 2005) because it is an ac- curate representation of actual storms of varying characteristics that are imbedded in intensity -duration -frequency (IDF) curves. For each duration of interest, a dimensionless hyetograph was devel- oped using a time increment of 12 s over the duration of the storm (see Fig. 3). The depth of rainfall that corresponds to each storm magnitude was then multiplied by the dimensionless hyetograph. For a 2-h storm duration, depths of 40.6, 76.2, and 101.6 mm were used for the 2-, 25-, and 100 -year events. The 2- and 6-h duration hyetographs were developed using the center portion of the 24-h storm, with the rainfall depths established with the Baltimore IDF curve. The corresponding depths for a 6-h duration were 53.3, 106.7, and 132.1 mm, respectively. These magnitudes were chosen to give a range of storm conditions. During each time increment, the depth of rain is multiplied by the cell area to determine the volume of rain added to each section of each cell. This volume becomes the storage in each cell. Depend- ing on the soil group, a constant volume of losses was subtracted from the storage. The runoff velocity from a solar panel was calcu- lated using Manning's equation, with the hydraulic radius for sheet flow assumed to equal the depth of the storage on the panel (Bedient and Huber 2002). Similar assumptions were made to com- pute the velocities in each section of the surface sections. 20 40 60 Time (min) 80 100 120 Fig. 3. Dimensionless hyetograph of 2-h Type II storm JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 537 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. Runoff from one section to the next and then to the next downgradient cell was routed using the continuity of mass. The routing coefficient depended on the depth of flow in storage and the velocity of runoff. Flow was routed from the wet section to the dry section to the spacer section, with flow from the spacer section draining to the wet section of the next cell. Flow from the most downgradient cell was assumed to be the outflow. Discharge rates and volumes from the most downgradient cell were used for com- parisons between the prepaneled and paneled conditions. Alternative Model Scenarios To assess the effects of the different variables, a section of 30 cells, each with a solar panel, was assumed for the base model. Each cell was separated individually into wet, dry, and spacer sections. The area had a total ground length of 225 m with a ground slope of 1% and width of 5 m, which was the width of an average solar panel. The roughness coefficient (Engman 1986) for the silicon solar panel was assumed to be that of glass, 0.01. Roughness coefficients of 0.15 for grass and 0.02 for bare ground were also assumed. Loss rates of 0.5715 cm/h (0.225 in./h) and 0.254 cm/h (0.1 in./h) for B and C soils, respectively, were assumed. The prepaneled condition using the 2-h, 25 -year rainfall was assumed for the base condition, with each cell assumed to have a good grass cover condition. All other analyses were made assum- ing a paneled condition. For most scenarios, the runoff volumes and peak discharge rates from the paneled model were not significantly greater than those for the prepaneled condition. Over a total length of 225 m with 30 solar panels, the runoff increased by 0.26 m3, which was a difference of only 0.35%. The slight increase in runoff volume reflects the slightly higher velocities for the paneled con- dition. The peak discharge increased by 0.0013 m3, a change of only 0.31%. The time to peak was delayed by one time increment, i.e., 12 s. Inclusion of the panels did not have a significant hydro- logic impact. Storm Magnitude The effect of storm magnitude was investigated by changing the magnitude from a 25 -year storm to a 2 -year storm. For the 2 -year storm, the rainfall and runoff volumes decreased by approximately 50%. However, the runoff from the paneled watershed condition increased compared to the prepaneled condition by approximately the same volume as for the 25 -year analysis, 0.26 m3. This increase represents only a 0.78% increase in volume. The peak discharge and the time to peak did not change significantly. These results re- flect runoff from a good grass cover condition and indicated that the general conclusion of very minimal impacts was the same for dif- ferent storm magnitudes. Ground Slope The effect of the downgradient ground slope of the solar farm was also examined. The angle of the solar panels would influence the velocity of flows from the panels. As the ground slope was in- creased, the velocity of flow over the ground surface would be closer to that on the panels. This could cause an overall increase in discharge rates. The ground slope was changed from 1 to 5%, with all other conditions remaining the same as the base conditions. With the steeper incline, the volume of losses decreased from that for the 1% slope, which is to be expected because the faster velocity of the runoff would provide less opportunity for infiltra- tion. However, between the prepaneled and paneled conditions, the increase in runoff volume was less than 1%. The peak discharge and the time to peak did not change. Therefore, the greater ground slope did not significantly influence the response of the solar farm. Soil Type The effect of soil type on the runoff was also examined. The soil group was changed from B soil to C soil by varying the loss rate. As expected, owing to the higher loss rate for the C soil, the depths of runoff increased by approximately 7.5% with the C soil when com- pared with the volume for B soils. However, the runoff volume for the C soil condition only increased by 0.17% from the prepaneled condition to the paneled condition. In comparison with the B soil, a difference of 0.35% in volume resulted between the two conditions. Therefore, the soil group influenced the actual volumes and rates, but not the relative effect of the paneled condition when compared to the prepaneled condition. Panel Angle Because runoff velocities increase with slope, the effect of the angle of the solar panel on the hydrologic response was examined. Analy- ses were made for angles of 30° and 70° to test an average range from winter to summer. The hydrologic response for these angles was compared to that of the base condition angle of 45°. The other site conditions remained the same. The analyses showed that the angle of the panel had only a slight effect on runoff volumes and discharge rates. The lower angle of 30° was associated with an in- creased runoff volume, whereas the runoff volume decreased for the steeper angle of 70° when compared with the base condition of 45°. However, the differences (-0.5%) were very slight. Never- theless, these results indicate that, when the solar panel was closer to horizontal, i.e., at a lower angle, a larger difference in runoff volume occurred between the prepaneled and paneled conditions. These differences in the response result are from differences in loss rates. The peak discharge was also lower at the lower angle. At an angle of 30°, the peak discharge was slightly lower than at the higher angle of 70°. For the 2-h storm duration, the time to peak of the 30° angle was 2 min delayed from the time to peak of when the panel was positioned at a 70° angle, which reflects the longer travel times across the solar panels. Storm Duration To assess the effect of storm duration, analyses were made for 6-h storms, testing magnitudes for 2-, 25-, and 100 -year return periods, with the results compared with those for the 2-h rainfall events. The longer storm duration was tested to determine whether a longer du- ration storm would produce a different ratio of increase in runoff between the prepaneled and paneled conditions. When compared to runoff volumes from the 2-h storm, those for the 6-h storm were 34% greater in both the paneled and prepaneled cases. However, when comparing the prepaneled to the paneled condition, the in- crease in the runoff volume with the 6-h storm was less than 1% regardless of the return period. The peak discharge and the time -to -peak did not differ significantly between the two condi- tions. The trends in the hydrologic response of the solar farm did not vary with storm duration. Ground Cover The ground cover under the panels was assumed to be a native grass that received little maintenance. For some solar farms, the area be- neath the panel is covered in gravel or partially paved because the panels prevent the grass from receiving sunlight. Depending on the 538 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. volume of traffic, the spacer cell could be grass, patches of grass, or bare ground. Thus, it was necessary to determine whether or not these alternative ground -cover conditions would affect the runoff characteristics. This was accomplished by changing the Manning's n for the ground beneath the panels. The value of n under the pan- els, i.e., the dry section, was set to 0.015 for gravel, with the value for the spacer or maintenance section set to 0.02, i.e., bare ground. These can be compared to the base condition of a native grass (n = 0.15). A good cover should promote losses and delay the runoff. For the smoother surfaces, the velocity of the runoff increased and the losses decreased, which resulted in increasing runoff vol- umes. This occurred both when the ground cover under the panels was changed to gravel and when the cover in the spacer section was changed to bare ground. Owing to the higher velocities of the flow, runoff rates from the cells increased significantly such that it was necessary to reduce the computational time increment. Fig. 4(a) shows the hydrograph from a 30 -panel area with a time incre- ment of 12 s. With a time increment of 12 s, the water in each cell is discharged at the end of every time increment, which results in no attenuation of the flow; thus, the undulations shown in Fig. 4(a) result. The time increment was reduced to 3 s for the 2-h storm, which resulted in watershed smoothing and a rational hydrograph shape [Fig. 4(b)] . The results showed that the storm runoff 0.1 0.09 0.08 0.07 coE 0.06 0 0.05 co 0 0.04 0.03 (a) 0.02 0.01 0 0.07 0.06 0.05 U) 0.04 0.03 0.02 0.01 20 40 60 80 100 120 140 160 180 Time (min) 0 _ 0 (b) I Paneled Pre -paneled 4 - alb NC IS 20 40 60 80 100 120 140 160 Time (min) 180 200 Fig. 4. Hydrograph with time increment of (a) 12 s; (b) 3 s with Manning's n for bare ground increased by 7% from the grass -covered scenario to the scenario with gravel under the panel. The peak discharge increased by 73% for the gravel ground cover when compared with the grass cover without the panels. The time to peak was 10 min less with the gravel than with the grass, which reflects the effect of differ- ences in surface roughness and the resulting velocities. If maintenance vehicles used the spacer section regularly and the grass cover was not adequately maintained, the soil in the spacer section would be compacted and potentially the runoff volumes and rates would increase. Grass that is not maintained has the potential to become patchy and turn to bare ground. The grass under the panel may not get enough sunlight and die. Fig. 1 shows the result of the maintenance trucks frequently driving in the spacer section, which diminished the grass cover. The effect of the lack of solar farm maintenance on runoff char- acteristics was modeled by changing the Manning's n to a value of 0.02 for bare ground. In this scenario, the roughness coefficient for the ground under the panels, i.e., the dry section, as well as in the spacer cell was changed from grass covered to bare ground (n = 0.02).The effects were nearly identical to that of the gravel. The runoff volume increased by 7% from the grass -covered to the bare -ground condition. The peak discharge increased by 72% when compared with the grass -covered condition. The runoff for the bare - ground condition also resulted in an earlier time to peak by approx- imately 10 min. Two other conditions were also modeled, showing similar results. In the first scenario, gravel was placed directly under the panel, and healthy grass was placed in the spacer section, which mimics a possible design decision. Under these conditions, the peak discharge increased by 42%, and the volume of runoff increased by 4%, which suggests that storm -water management would be necessary if gravel is placed anywhere. Fig. 5 shows two solar panels from a solar farm in New Jersey. The bare ground between the panels can cause increased runoff rates and reductions in time of concentration, both of which could necessitate storm -water management. The final condition modeled involved the assumption of healthy grass beneath the panels and bare ground in the spacer section, which would simulate the con- dition of unmaintained grass resulting from vehicles that drive over the spacer section. Because the spacer section is 53% of the cell, the change in land cover to bare ground would reduce losses and de- crease runoff travel times, which would cause runoff to amass as it Fig. 5. Site showing the initiation of bare ground below the panels, which increases the potential for erosion (photo by John Showler, reprinted with permission) JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 539 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. moves downgradient. With the spacer section as bare ground, the peak discharge increased by 100%, which reflected the increases in volume and decrease in timing. These results illustrate the need for maintenance of the grass below and between the panels. Design Suggestions With well -maintained grass underneath the panels, the solar panels themselves do not have much effect on total volumes of the runoff or peak discharge rates. Although the panels are impervious, the rainwater that drains from the panels appears as runoff over the downgradient cells. Some of the runoff infiltrates. If the grass cover of a solar farm is not maintained, it can deteriorate either because of a lack of sunlight or maintenance vehicle traffic. In this case, the runoff characteristics can change significantly with both runoff rates and volumes increasing by significant amounts. In addition, if gravel or pavement is placed underneath the panels, this can also contribute to a significant increase in the hydrologic response. If bare ground is foreseen to be a problem or gravel is to be placed under the panels to prevent erosion, it is necessary to counteract the excess runoff using some form of storm -water man- agement. A simple practice that can be implemented is a buffer strip (Dabney et al. 2006) at the downgradient end of the solar farm. The buffer strip length must be sufficient to return the runoff character- istics with the panels to those of runoff experienced before the gravel and panels were installed. Alternatively, a detention basin can be installed. A buffer strip was modeled along with the panels. For approxi- mately every 200 m of panels, or 29 cells, the buffer must be 5 cells long (or 35 m) to reduce the runoff volume to that which occurred before the panels were added. Even if a gravel base is not placed under the panels, the inclusion of a buffer strip may be a good prac- tice when grass maintenance is not a top funding priority. Fig. 6 shows the peak discharge from the graveled surface versus the length of the buffer needed to keep the discharge to prepaneled peak rate. Water draining from a solar panel can increase the potential for erosion of the spacer section. If the spacer section is bare ground, the high kinetic energy of water draining from the panel can cause soil detachment and transport (Garde and Raju 1977; Beuselinck et al. 2002). The amount and risk of erosion was modeled using the velocity of water coming off a solar panel compared with the velocity and intensity of the rainwater. The velocity of panel 0.07 0.06 0.05 M 0.04 0 11 0.03 o_ 0.02 0.01 5 10 15 20 25 Length of buffer (m) Pre -paneled peak Q Peak Q vs. buffer length - 30 35 40 Fig. 6. Peak discharge over gravel compared with buffer length runoff was calculated using Manning's equation, and the velocity of falling rainwater was calculated using the following: Vt = 120 d).35 (1) where d,. = diameter of a raindrop, assumed to be 1 mm. The re- lationship between kinetic energy and rainfall intensity is Ke = 916 + 3301og10 i (2) where i = rainfall intensity (in./h) and Ke = kinetic energy (ft -tons per ac -in. of rain) of rain falling onto the wet section and the panel, as well as the water flowing off of the end of the panel (Wischmeier and Smith 1978). The kinetic energy (Salles et al. 2002) of the rain- fall was greater than that coming off the panel, but the area under the panel (i.e., the product of the length, width, and cosine of the panel angle) is greater than the area under the edge of the panel where the water drains from the panel onto the ground. Thus, dividing the kinetic energy by the respective areas gives a more accurate representation of the kinetic energy experienced by the soil. The energy of the water draining from the panel onto the ground can be nearly 10 times greater than the rain itself falling onto the ground area. If the solar panel runoff falls onto an un- sealed soil, considerable detachment can result (Motha et al. 2004). Thus, because of the increased kinetic energy, it is pos- sible that the soil is much more prone to erosion with the panels than without. Where panels are installed, methods of erosion control should be included in the design. Conclusions Solar farms are the energy generators of the future; thus, it is im- portant to determine the environmental and hydrologic effects of these farms, both existing and proposed. A model was created to simulate storm -water runoff over a land surface without panels and then with solar panels added. Various sensitivity analyses were conducted including changing the storm duration and volume, soil type, ground slope, panel angle, and ground cover to determine the effect that each of these factors would have on the volumes and peak discharge rates of the runoff. The addition of solar panels over a grassy field does not have much of an effect on the volume of runoff, the peak discharge, nor the time to peak. With each analysis, the runoff volume increased slightly but not enough to require storm -water management facili- ties. However, when the land -cover type was changed under the panels, the hydrologic response changed significantly. When gravel or pavement was placed under the panels, with the spacer section left as patchy grass or bare ground, the volume of the runoff in- creased significantly and the peak discharge increased by approx- imately 100%. This was also the result when the entire cell was assumed to be bare ground. The potential for erosion of the soil at the base of the solar pan- els was also studied. It was determined that the kinetic energy of the water draining from the solar panel could be as much as 10 times greater than that of rainfall. Thus, because the energy of the water draining from the panels is much higher, it is very possible that soil below the base of the solar panel could erode owing to the concen- trated flow of water off the panel, especially if there is bare ground in the spacer section of the cell. If necessary, erosion control meth- ods should be used. Bare ground beneath the panels and in the spacer section is a realistic possibility (see Figs. 1 and 5). Thus, a good, well - maintained grass cover beneath the panels and in the spacer section is highly recommended. If gravel, pavement, or bare ground is 540 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. deemed unavoidable below the panels or in the spacer section, it may necessary to add a buffer section to control the excess runoff volume and ensure adequate losses. If these simple measures are taken, solar farms will not have an adverse hydrologic impact from excess runoff or contribute eroded soil particles to receiving streams and waterways. Acknowledgments The authors appreciate the photographs (Figs. 1 and 5) of Ortho Clinical Diagnostics, 1001 Route 202, North Raritan, New Jersey, 08869, provided by John E. Showler, Environmental Scientist, New Jersey Department of Agriculture. The extensive comments of reviewers resulted in an improved paper. References Bedient, P. B., and Huber, W. C. (2002). Hydrology and,floodplain analy- sis, Prentice -Hall, Upper Saddle River, NJ. Beuselinck, L., Govers, G., Hairsince, P. B., Sander, G. C., and Breynaert, M. (2002). "The influence of rainfall on sediment transport by overland flow over areas of net deposition." J. Hydrol., 257(1-4), 145-163. Dabney, S. M., Moore, M. T., and Locke, M. A. (2006). "Integrated man- agement of in -field, edge -of -field, and after -field buffers." J. Amer. Water Resour. Assoc., 42(1), 15-24. Engman, E. T. (1986). "Roughness coefficients for routing surface runoff." J. Irrig. Drain. Eng., 112(1), 39-53. Garde, R. J., and Raju, K. G. (1977). Mechanics of sediment transportation and alluvial stream problems, Wiley, New York. McCuen, R. H. (2005). Hydrologic analysis and design, 3rd Ed., Pearson/ Prentice -Hall, Upper Saddle River, NJ. Motha, J. A., Wallbrink, P. J., Hairsine, P. B., and Grayson, R. B. (2004). "Unsealed roads as suspended sediment sources in agricultural catch- ment in south-eastern Australia." J. Hydrol., 286(1-4), 1-18. Salles, C., Poesen, J., and Sempere-Torres, D. (2002). "Kinetic energy of rain and its functional relationship with intensity." J. Hydrol., 257(1-4), 256-270. Wischmeier, W. H., and Smith, D. D. (1978). Predicting rainfall erosion losses: A guide to conservation planning, USDA Handbook 537, U.S. Government Printing Office, Washington, DC. JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 541 J. Hydrol. Eng. 2013.18:536-541. Kimley >) Horn PRELIMINARY DRAINAGE REPORT Blue Spruce Solar Weld County Case # TBD Northeast of the intersection of Weld County Rd 44 and Weld County Road 45 Weld County, CO Prepared by: Kimley-Horn Inc. 1125 17th Street, Suite 1400 Denver, CO 80202 Contact: Adam Harrison, P.E. Phone: (303) 228-2311 Prepared on: July 06, 2023 Blue Spruce Solar — Weld County, CO July 2023 Page 1 Kimley >) Horn TABLE OF CONTENTS 1. PROJECT DESCRIPTION & SCOPE OF WORK 3 1.1. Project Location 3 1.2. Nearby Water Features & Ownership 4 1.3. Report & Analysis Methodologies 4 1.4. Stormwater Management 5 2. CONCLUSION 5 EXHIBITS Exhibit 1 - FEMA Firm Map Exhibit 2 - NRCS Report Exhibit 3 — NOAA Rainfall Data Exhibit 4 — Pre -Development Drainage Area Map Exhibit 5 — Post -Development Drainage Area Map Exhibit 6 — Hydrologic Calculations & Detention/WQCV Calculations Exhibit 7 — Hydrologic Response of Solar Farms Blue Spruce Solar — Weld County, CO July 2023 Page 2 Kimley >) Horn 1. PROJECT DESCRIPTION & SCOPE OF WORK The development is a proposed 10.0-MWac Solar power generating facility located in Weld County, CO. The solar power generating facility will consist of rows of Photovoltaic Solar Modules, gravel access driveways, associated electrical equipment, underground utilities, and a substation (by others). Solar modules will be mounted on piles and elevated above the ground as to preserve the existing underlying soil and allow for revegetation and infiltration. The project will be surrounded by a perimeter fence. Ground area within the limits of development that is not occupied by gravel roads or foundations will be seeded to establish permanent vegetation. This drainage narrative is intended to provide Weld County with preliminary information regarding the drainage and land disturbance activities related to the proposed Michael Boulter South Solar, small scale solar facility (Project). The project will be designed and will be constructed and maintained in a manner that minimizes storm water related impacts, in accordance with Weld County drainage criteria. Project name, Property Address and Weld County Parcel No. Michael Boulter Solar, 22001-22999 WCR 44 Weld 80645, Parcel No. 105514300030 Developer/Owner CloudBreak Energy Partners, LLC, 218 S. 3rd Street Sterling, CO 80751 Urbanizing/Non-Urbanizing This site is located more than a quarter mile away from the nearest Weld County municipal boundary and is classified as "Non -Urbanizing". Therefore, detention ponds designed for this site would be sized using 10 -year runoff rates. 1.1. Project Location The existing site subject property is a parcel of 152.6 acres. The project is located on approximately 96.86 acres of lightly vegetated land. The project is located south east of La Salle, within Weld County. The site is bounded to the north by property owned by Michael Boulter Farms LLC (Parcel 105514200025), to the east by parcel 105514000014 owned by the city of Broomfield, to the west by WCR 45 and to the south by WCR 44. Section Township Range Property is located within a portion of the south west quarter of Section 14, Township 4 North, Range 65 West of the 6th P.M., Weld County, Colorado. Per FEMA Map Panels 08123C1750E effective 01/20/2016, none of the development area is within a flood hazard area. (Refer to Exhibit 1 for FEMA Map). The NRCS Report dated 04/28/2023, concludes that onsite soils consist mostly of Aquolls and Aquepts, Vona sandy loam and Vona loamy sand, and Otero sandy loam that classify as hydrologic soil groups (HSG) type A and D. The site was modeled using all type D soils. For additional detail, refer to Exhibit 2 for the NRCS Report. Blue Spruce Solar — Weld County, CO July 2023 Page 3 Kimley >) Horn 1.2. Nearby Water Features & Ownership In the existing condition, a majority of the site drains to the surrounding agricultural and lightly vegetated property of the same parcel number as the project site. The nearest water feature is Gilmore Ditch approximately 0.7 miles east of the project area. Gilmore Ditch is the receiving water of the project site. The existing drainage patterns will be maintained in the proposed condition. Refer to Exhibit 4 and Exhibit 5 for the Pre and Post -Development Drainage Area Maps. 1.3. Report & Analysis Methodologies This report evaluates the pre and post development runoff characteristics of the development (including solar facility footprint and access drive) and addresses the stormwater requirements of Weld County and the state of Colorado. Hydrologic Design Criteria The table below notes the hydrologic design criteria used in the analysis. Parameter Value Unit Reference Time of Concentration, Tc - min. Exhibit 6 Runoff Coefficient, C - - MHFD Criteria Manual, Chapter 6, Table 6-4 1 -hr Point Rainfall, P1 (100 -Year) 2.71 Inches NOAA Rainfall Data (Exhibit 3) Storm Runoff, Q - cfs Q = CIA Basin Conditions The drainage areas of the site are shown for the site as Pre -construction (Exhibit 4) and Post - construction (Exhibit 5). Pre -construction drainage basins were analyzed to calculate the peak existing runoff for the design storm. Post -construction drainage basins were analyzed to calculate the peak runoff for the design storm in the proposed site conditions. The Weld County Construction and Design Criteria requires areas of proposed solar arrays over a Type D soil classification to utilize an imperviousness of 25%. The total imperviousness for the proposed site was calculated to be 6.7% (see Exhibit 6 for the imperviousness summary). The area under the solar panels will be planted with a low -maintenance grass seed mix, in order to mimic natural processes to manage stormwater, which follows the Low -Impact Development (LID) approach. The existing drainage basins 1,3,5,8,9,10,12,13,14,16, and 20 under existing conditions currently pond across the site. The projects proposed conditions will utilize grading and storm infrastructure to create positive drainage of the entire site. The existing site use is agricultural row crops most similar to tillage/agricultural land classification, which does not exhibit the characteristics of a low -impact development. By utilizing the native grass seed mix below the panels, the existing tillage/agricultural land areas will be changed to a heavy meadow land classification that reduces peak flow rates and manages stormwater in line with the historic conditions of the site. The site design promotes conservation design at both the watershed and site levels, with the goal of replicating the native hydrologic characteristics of the sub -watersheds, creating natural ground coverage, and minimizing proposed grading and Blue Spruce Solar — Weld County, CO July 2023 Page 4 Kimley >) Horn compaction. The site will not receive offsite drainage and offsite drainage patterns will remain the same as historic conditions. Stormwater Runoff The stormwater runoff for existing and proposed conditions is calculated utilizing the Rational Method. The 100 -year, 1 -hour storm event was analyzed for pre and post -construction drainage basins. The flow path for the basins can be seen in Exhibits 4 & 5. The time of concentration to the point of accumulation was calculated using MHFD equations and can be found in Exhibit 6. The Runoff Coefficients are also included in Exhibit 6. The precipitation data used for the 100 - year, 1 -hour storm event is based on NOAA rainfall data from the project site (Exhibit 3). A summary of the rational calculation findings is shown in the table below. Existing Proposed Area 96.86 ac 96.86 ac Imperviousness 2.8 % 6.7 CQloo 116.3cfs 108.5cfs 1.4. Stormwater Management A study published in the Journal of Hydrologic Engineering researched the hydrologic impacts of utility scale solar generating facilities. The study utilized a model to simulate runoff from pre -and post -solar panel conditions. The study concluded that the solar panels themselves have little to no impact on runoff volumes or rates. Rainfall losses, most notably infiltration, are not impacted by the solar panels. Rainfall that falls directly on a solar panel runs to the pervious areas around and under the surrounding panels. Refer to Exhibit 7 for the study published in the Journal of Hydrologic Engineering. Under developed conditions, runoff will follow existing drainage patterns and will reduce peak flows (decreases from 116.3 cfs to 108.5 cfs in the 100-year,1-hour storm event). 2. CONCLUSION The following list summarizes key components of the Project and findings related to land disturbance and storm water impacts. • Installation of the solar facility will temporarily disturb the ground surface within the 96.86 acre Project area, but won't require clearing and grubbing of vegetation or grading, except for concrete equipment pads and gravel access drive installations. • The areas considered impervious or semi -impervious are a large portion of the project area, however the semi -impervious areas under the solar panels (modeled as 25% impervious) represent 15% of the total site area, and by implementing low -maintenance grass seed mix underneath, the site will reduce peak flow rates from existing conditions. • Under existing conditions, the peak flow from the site area for the 100 yr — 1 hr storm event is 116.3 cfs. • Under developed conditions, the peak flow from the site area for the 100 yr — 1 hr storm event is 108.5 cfs. • Installation of the solar facility is not expected to impact existing drainage patterns or flow rates on or around the project site. Runoff water quality will not be impacted by the solar facility components. Blue Spruce Solar — Weld County, CO July 2023 Page 5 Kimley >) Horn • The project design will adequately protect public health, safety and general welfare and have no adverse effects on Weld County right-of-way or offsite properties. As noted above, a study published in the Journal of Hydrologic Engineering (Exhibit 7) researched the hydrologic impacts of utility scale solar generating facilities. The study utilized a model to simulate runoff from pre -development and post -development solar panel conditions. The study concluded that the solar panels themselves have little to no impact on runoff volumes or rates. Rainfall losses, most notably infiltration, are not impacted by the solar panels. Rainfall that falls directly on a solar panel runs to the pervious areas around and under the surrounding panels. Grading is proposed with minimal changes to the existing site drainage patterns and onsite access roads will be made of gravel. Based on the proposed improvements on the project site, the findings of the above referenced study, and the calculations included within this report, the site will reduce peak flows from the existing rates. Therefore, permanent stormwater detention and water quality facilities are not proposed with the project. We trust that the information provided is acceptable and complete for preliminary site plan review drainage report requirements. Please let us know if you have any questions or need additional information. KIMLEY-HORN LEY -HORN AND ASSOCIATES, INC. Adam Harrison, PE Project Manager Blue Spruce Solar — Weld County, CO July 2023 Page 6 Exhibit 1 — FEMA Firm Map National Flood Hazard Layer FIRMette FEMA Legend 104°38'23"W 40°18'44"N 104°37'46"W 40°18'16"N SLVEIJ) I:_ 0 250 500 1,000 1,500 08.12_ 1/20/2016 Not Printed T4N F 65W S23 2,000 Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 PROJECT AREA J saant Feet 1:6,000 SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V. A99 With BFE or Depth Zone AE, AO, AN, VE, AR Regulatory Floodway OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Future Conditions 1% Annual Chance Flood Hazard Area with Reduced Flood Risk due to Levee. See Notes. Zone X Area with Flood Risk due to Levee Zone D NO SCREEN Area of Minimal Flood Hazard zone x Effective LOM Rs Area of Undetermined Flood Hazard Zone D - Channel, Culvert, or Storm Sewer milli Levee, Dike, or Floodwall 20.2 Cross Sections with 1% Annual Chance 1765 Water Surface Elevation 8 - - - - Coastal Transect .� ,1 n Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary - - - Coastal Transect Baseline Profile Baseline Hydrographic Feature Digital Data Available No Digital Data Available Unmapped The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 4/28/2023 at 10:46 AM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Exhibit 2 — NRCS Report 40° 18' 42" N S 40° 18' 16" N S 104° 38' 32" W 104° 38' 32" W Hydrologic Soil Group —Weld County, Colorado, Southern Part 530500 530600 530700 530800 530900 Map Scale: 1:5,630 if printed on A landscape (11" x 8.5") sheet Meters 0 50 100 200 300 531000 531100 531200 Feet 0 250 500 1000 1500 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 531600 I I I 531300 531400 531500 531600 104° 37' 39" W 104° 37 39" W co Co 40° 18' 42" N 40° 18' 16" N ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 4/28/2023 Page 1 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part MAP LEGEND Area of Interest (AO!) Area of Interest (A01) ) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines 0 0 A A/D B B/D C C/D D Not rated or not available Soil Rating Points II O O O A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background ,; Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 21, Sep 1, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 8, 2021 Jun 12, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 4/28/2023 Page 2 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 4 Aquolls flooded and Aquepts, D 57.5 58.7% 50 Otero sandy loam, percent slopes 0 to 1 A 15.9 16.3% 70 Valent sand, percent slopes 3 to 9 A 19.9 20.3% 72 Vona percent loamy slopes sand, 0 to 3 A 1.5 1.5% 76 Vona sandy loam, percent slopes 1 to 3 A 3.2 3.3% Totals for Area of Interest 98.0 100.0% e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/28/2023 Page 3 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and CID). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, BID, or CID), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie -break Rule: Higher e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/28/2023 Page 4of4 Exhibit 3 — NOAA Rainfall Data NOAA Atlas 14, Volume 8, Version 2 Location name: La Salle, Colorado, USA* Latitude: 40.3066°, Longitude: -104.6379° Elevation: 4700.91 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES V 1 I LI1111 - �C S U+` 'MFq rp Or Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration 5 -min J 10 -min J 1 15 -min 30 -min 60 -min 2 -hr 3 -hr 6 -hr 12 -hr 24 -hr 2 -day 3 -day 4 -day 7 -day 10 -day 20 -day 30 -day 45 -day 60 -day Average recurrence interval (years) 0.242 (0.198-0.299) 0.355 (0.291-0.437) 0.433 (0.354-0.533) 0.580 (0.475-0.715) 0.720 (0.590-0.887) 0.859 (0.709-1.05) 0.941 (0.780-1.15) 1.09 (0.907-1.31) 1.27 (1.07-1.52) 1.51 (1.28-1.79) 1.73 (1.48-2.04) 1.90 (1.62-2.22) 2.02 (1.74-2.36) 2.30 (1.99-2.67) 2.55 (2.21-2.93) 3.25 (2.85-3.71) 3.82 (3.36-4.34) 0.293 (0.240-0.362) 0.429 (0.351-0.530) 0.523 (0.428-0.646) 0.700 (0.573-0.864) 0.856 (0.700-1.06) 1.01 (0.833-1.24) 1.10 [(0.906-1.33) 1.27 (1.06-1.53) 1.51 (1.26-1.80) 1.78 1.50-2.11) 2.06 (1.75-2.42) 2.22 1.90-2.60) 2.36 (2.02-2.75) 2.69 (2.32-3.11) 2.97 (2.58-3.43) 3.76 (3.29-4.29) 4.39 (3.86-4.99) 4.51 (3.98-5.09) 5.06 (4.48-5.70) 5.18 (4.57-5.85) 5.84 (5.17-6.58) 5 0.390 (0.318-0.483) 0.571 (0.466-0.708) 0.697 (0.568-0.863) 0.932 (0.759-1.15) 1.13 (0.920-1.40) 1.33 (1.09-1.63) 1.42 (1.17-1.74) 1.65 (1.37-2.00) 10 0.484 (0.392-0.603) 0.709 (0.574-0.882) 0.865 (0.700-1.08) 1.16 (0.936-1.44) 1.40 1.14-1.75) 1.65 1.35-2.04) 1.77 (1.45-2.17) 2.04 1.68-2.48) 1.95 1.63-2.34) 2.38 (1.97-2.87) 2.27 2.72 (1.91-2.70) (2.28-3.26) 2.62 II 3.13 2.23-3.10)JL (2.64-3.71) 2.80 I 3.30 2.38-3.28) _ [(2.80-3.90) 2.94 3.45 (2.51-3.43)J (2.93-4.05) 3.34 if 3.89 (2.87-3.87) IL (3.33-4.54) 3.68 (3.18-4.25) 4.58 (3.98-5.24) 5.30 (4.64-6.05) 6.24 (5.49-7.08) 7.06 (6.22-7.97) 4.27 (3.67-4.96) 5.24 (4.54-6.03) 25 0.633 (0.500-0.845) 0.927 (0.732-1.24) 1.13 (0.892-1.51) 1.52 (1.20-2.03) 1.85 (1.47-2.49) 2.19 (1.76-2.93) 2.36 (1.90-3.14) 2.68 (2.17-3.52) 3.05 (2.47-3.92) 3.43 (2.79-4.34) 3.87 (3.16-4.81) 4.05 (3.32-5.01) J 4.20 (3.46-5.17) 4.68 J (3.86-5.68) 5.09 (4.21-6.12) 6.04 (5.25-6.92) 7.09 (6.19-8.08) 8.02 (7.03-9.10) 6.14 (5.11-7.28) 7.03 (5.87-8.27) 8.21 (6.88-9.59) 9.28 (7.79-10.8) 50 0.763 (0.582-1.03) 1.12 (0.851-1.51) 1.36 (1.04-1.84) 1.83 (1.40-2.47) 2.26 (1.72-3.05) 2.68 (2.07-3.61) 100 0.907 (0.661-1.26) 1.33 (0.969-1.84) 1.62 (1.18-2.24) 2.18 (1.59-3.02) 2.71 (1.98-3.77) 3.24 (2.39-4.47) 2.89 (2.25-3.88) 3.26 (2.55-4.31) 3.63 (2.85-4.72) 4.02 (3.18-5.15) 4.48 (3.55-5.64) 4.67 (3.72-5.85) 4.82 (3.86-6.01) 5.31 (4.26-6.54) 5.73 (4.62-7.00) 6.83 (5.54-8.23) 7.77 (6.33-9.29) (7.9.04 40-10.7) 10.2 (8.37-12.0) 3.50 (2.60-4.82) 3.91 (2.93-5.31) 4.28 (3.22-5.71) 4.67 (3.54-6.15) 5.12 (3.90-6.63) 5.32 (4.07-6.84) 5.47 (4.21-7.01) 5.95 (4.60-7.53) 6.38 (4.95-8.00) 7.50 (5.87-9.28) 8.49 (6.67-10.4) 9.83 (7.76-12.0) 11.1 (8.75-13.4) 200 1.07 (0.739-1.52) 1.56 1.08-2.23) 1.91 (1.32-2.72) 2.57 (1.78-3.67) 3.22 (2.23-4.61) 3.86 (2.71-5.49) 4.20 (2.96-5.94) 4.65 (3.31-6.50) 500 1000 1.30 (0.857-1.91) 1.90 (1.25-2.80) 2.32 (1.53-3.41) 3.14 (2.07-4.61) 1.49 (0.947-2.20) 2.18 (1.39-3.23) 2.66 (1.69-3.93) 3.60 (2.29-5.32) 3.97 2.62-5.84) 4.80 (3.20-7.01) 4.59 (2.92-6.78) 5.58 (3.58-8.15) 5.24 (3.52-7.61) 5.75 (3.90-8.26) 4.99 I 6.0252) 3.57-6.85)J 5.38 (3.89-7.30) 5.81 (4.22-7.75) 6.01 (4.39-7.97)J 6.17 (4.53-8.14) 6.63 (4.89-8.64) 7.04 (5.21-9.09) 8.17 (6.11-10.4)]L 9.20 (6.90-11.6)J 10.6 (8.00-13.3) 11.9 (8.99-14.8) 6.40 (4.42-8.94) 6.77 (4.70-9.31) C 6.98 (4.88-9.54) 7.14 (5.01-9.71) 7.55 (5.33-10.1) 7.92 (5.62-10.5) 9.05 (6.48-11.9) 10.1 (7.27-13.2) 11.6 (8.37-14.9) 12.9 (9.36-16.6) 6.11 (3.94-8.88) 6.67 (4.35-9.58) 6.87 (4.53-9.78) 7.24 (4.82-10.2) 7.54 (5.07-10.5) 7.76 (5.25-10.7) 7.92 (5.38-10.9) 8.27 (5.67-11.3) 8.59 (5.93-11.6) 9.70 (6.76-13.0) 10.8 (7.55-14.3) 12.2 (8.65-16.2) 13.6 (9.65-17.9) Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical PDS-based depth -duration -frequency (DDF) curves Latitude: 403066°r Longitude: -104.6379° Precipitation depth (in) 14 12 10 14 12 10 1 a 1 i 1 1 1 1 I I I 1 1 1 I I I 1 I I I I e e I 1 I 1 I I I I 1 a a 1 I 1 1 1 1 1 1 1 a 1 1 a a I 1 I 1 I I I I I I 1 1 1 1 I I I I 1 a a a a a a a a 1 1 1 1 1 Y a .... . .1. • as . . Pr . . . . . L . . _ . . ,.I _ . .I .. _ .a .. _ . ../1 . _ ..1_ _ . . . L. . . . .. I. . _ .. I. a a e I 1 4 Y a • • . • a a a a • a • • a a a I 1 I I 1 1 1 a I 1 I 1 1 1 I I • • I I • • • I P I P I I • • 1 1 1 1 1 1 1 a 1 1 a 1 a a 1 1 V I I I I I e t e a IF I I a I a a 1 a a a a 1 a a a a a a a a a a s i a a i i i a 1 • a a if ! a 1 1 I I I I 1 1 t t t . 1 a I p . I vl al a 1 1 1 1 1 a e e e I I I I e 1 e e e I e I I I • • • 1t I I I I 1 1 1 I I 1 a I i I I / 1 1 e g a I a e e • • e e -- . —— t 1 I I I I I I a i -_ _ 1• — • I I a 1 I a a a a 1 ....-.a t Y Y- e a . Y 1 1 a 1 a � a a e e 1 a 1 1 a a I ....rears— I I I 5 • I Y • - 'J • • • - - i 1 1 a 1 1 Y 1 - 1 1 1 a a a 1 I a I 1 a I a t - i { • I I 1 ! 1 f e I I I I I I I t ! t ! I i r - — — — — — — — — — • t •. _ — — — _ _ _ _ Y— — 1 — '. — — I— — —I•_ .. — — I 1 1 I 1 a i - 1 1 a i 1 a e e e e I I a a I • e Y 1 1 a a 1 a e e T - ! a�fi II ! ! e e e a 1 I C c e t'•J 1 _ LA 5 10 25 50 100 200 NOM Atlas 14, Volume 8, Version 2 C 1•D 1 1 Duration :- = .�•i 1 i3 111 a I to I I N ICIrzi Average recurrence interval (years) ro Co rp V V V t 6 u1 6 N f #Le 500 1000 Created {GMT): Mon Feb 6 20:20:13 2023 Back to Top Maps & aerials Small scale terrain Average recurrence interval (years) 1 2 5' 10 25 50 100 200 500 1 000 Duration 5-mp — 2 -day 10-mon — 3 -day 15' -min — 4 -day 30 -min — 7 -day 6 Din - 10 -day 2 -hr — 2.0 -day 34',r — 30 -day. 5 -hr — 45 -day .112 -ht 50 -day 24 -hr Nastesiesturiset Lmna'f?'1 R e c ervo l,r -, SE 3km 2mi EASTON VA L El VIEW avhc: ARPO,R Elba - _; A Large scale terrain Large scale map S Large scale aerial Cheyenne - Ireeley ■I L'? ngm ln Boulder 100km 60mi -11 er Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?: HDSC.Questions@noaa.gov Disclaimer Exhibit 4 — Pre -Development Drainage Area Map re_____r_e____,____ irs Lim 1 iS . i ' dp\ 1 • ; --- / \ % % % ,/c._,,,, T ,C, I 7 , 1, . N / I.` I e • _ ... • 'VI __,- a r 'S / y ` /0 / ki.,„A---\ , 4.4 s7 "IC \ ."'".. ''....• N ) % / / A I 'I( 41 i It ''\ I % % S ( \ i / ` ` \ 1, 1 CL 'yT E ' ` _ _, , . I 4 ) , s i 1 0 I, • � -, yq \st� _ any ` � `I `I 1 h• 1.1.1.•41, s /) R� ~��A Ss ..` y.. N ' v °' `\ F I I� -,A ‘v , D.,..... .... a L ' 1 . - - -__J- I a r ati R 4.., r 4.64 _ -� •_'C F J 7..7 /67:1";) ismS arm-•>—++ ..rte ea a — • I-41 a — ■sue —� _ ( �` v a • • t- • a -a masa a sa sea ea ara •f a as a G**P'.C SCALE W BEET 0 ]0 '00 700 LEGEND .RORV IV ROLANWAT, in al a ea PRE COISIONS La IASWLS' Ea SR rasa Et uallOIO.AO CAS LAC La SPAM VOL,LICE fa CANAsitaa oaf Ell 1 Of MW (IT PC )4)4 gyzini NOTES f t CONTOURS Ct VEnvOUS Y11YKi EA Oat ICAO Fa sr AAf SUB .3AcN --any Wog �vPkaN0U5Ntt55 ,'. a Oka (AC35; ''•S 09MMACE VAP AND M' K01MA'0. COnNIEO MAIN Ma *SSOOASI'- C.QASEA• L%&SG' PAA•1SRt LAX OgtMA0f ♦AWO- VC' AM LASE RV ST ca EWE PASS 2. W IN iWeRL.%CE t0 fist P1JtRA. WLAOENCY YAVAE;VEN' AMC (gin) T.000 SS.AAKS. *Ark NM (IIRO. NA? NUNM'4 OBI 23C' 7SOE --ETV air NO n.0000. MSS *?H* '-t W IS 0< Hit 010ACI SIM tS10A1O s- t.• ]RAIN it .04 OEOa'y At All 1?- 07/0•/7011 Y 0. Q 2 Li O w re 0 m <fig w Q DJOcccr O C-o Z Wl O F a 3 N V Erg). - z Ds 9 O w m a r- OR aEVEIV OR -it NOT FOR C0KSTRLJCTI0N Mandeplism ..r.-.. as V �R;SI. .D asak.JOc :lair.. \AV• EX -4 Exhibit 5 — Post -Development Drainage Area Map \tts % C,.r�S..I\Ctra.C9,w>, ftit'000 wwa Cars Pat.t. M�iclwt Halls - Lbw CA�7r i ttvxs - OVAMaCf VY POSt..9 .la•� 7 �pJJ 10 .7 wu .. l .f! •— •l1M I�OI) A—*SSS*S&tt-- !) S__I _t i., .•a 1_I.Y, I YI>• of..lam -I C�/�//�•.//. • 11 I I I I I Uc1 III 1 1 i I t I - �1 II _ 1 / 1 1 I 1 I1 1 1 I n.e S a -♦ Se 11 7 4 t It _ f�T I t. ..V I Ir —� tf 1 I I 1 1 t _ t 1 r I C 1\ t I _ • I / r • OO /I I , - It _ r II It S S de MI MI e I l > t 4 elmoss--..typ a wr _ i I #4 It t t _ t - I Kl fei I r t 1 I _ t 4 _ t - I I 'y I ii t t _ t _ It _ 1 4 - - 4 (! r 4. I St 4) tt r t I. I I/ 4 I- 9. 1 .!1=44 II Se rI t ti • • 'S I I • $4 l I If - �t I 4 • r I I I�g 'la I., i w I p pp P $ ; I hi R r k 2 S BOULTER - CLOUDBREAK WELD COUNTY. COLORADO USE BY SPECIAL REVIEW POST -CONSTRUCTION DRAINAGE MAP Kimley* Horn e J023 *Witt-+t01M AMO ASS0CARi ►.C '130 I!Ts SIQI'. SIR;t 't00 OS'.,... Caine 40707 (70:S) 274 2300 m m Z 0 CLOUDSMtAK Kimley>>)Horn_ STANDARD FORM SF 1 RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION - PRE -CONSTRUCTION PROJECT NAME: PROJECT NUMBER: 196664000 Weld County - Cloudbreak - Michael Boulter South 7/6/2023 CALCULATED BY: JCH CHECKED BY: AJH TYPE D SOIL VEGETATED BUILDING FUTURE LAND PAVED GRAVEL USE: AREA AREA OPEN AREA SPACE ROOF COMMERCIAL AREA AREA 2 -YEAR COEFF. 0.83 0.30 0.01 0.74 0.69 5 -YEAR COEFF. 0.84 0.36 0.05 0.76 0.72 100 -YEAR COEFF. 0.89 0.65 0.49 0.85 0.83 IMPERVIOUS % 100% 40% 2% 90% 85% DESIGN BASIN Cc(2) Cc(5) Cc(100) Imp % VEGETATED BUILDING FUTURE PAVED GRAVEL OPEN SPACE ROOF COMMERCIAL TOTAL DESIGN AREA AREA AREA AREA AREA AREA POINT (AC) (AC) (AC) (AC) (AC) (AC) On -Site Basins PRE -DA -01 1 3.02 3.02 0.01 0.05 0.49 2.0% PRE -DA -02 2 3.23 3.23 0.01 0.05 0.49 2.0% PRE -DA -03 3 13.25 13.25 0.01 0.05 0.49 2.0% PRE -DA -04 4 0.41 15.18 15.59 0.02 0.06 0.50 3.0% PRE -DA -05 5 0.19 9.05 9.24 0.02 0.06 0.50 2.8% PRE -DA -06 6 0.15 2.86 3.01 0.02 0.07 0.50 3.9% PRE -DA -07 7 1.92 1.92 0.01 0.05 0.49 2.0% PRE -DA -08 8 0.29 4.54 4.82 0.03 0.07 0.50 4.3% PRE -DA -09 9 6.14 6.14 a 0.01 0.05 0.49 2.0% PRE -DA -10 10 0.06 7.78 7.84 0.01 0.05 0.49 2.3% PRE -DA -11 11 1.61 1.61 0.01 0.05 0.49 2.0% PRE -DA -12 12 0.06 2.01 2.07 0.02 0.06 0.50 3.1% PRE -DA -13 13 0.78 3.54 4.32 0.06 0.11 0.52 8.9% PRE -DA -14 14 0.04 3.17 3.21 0.01 0.06 0.49 2.5% PRE -DA -15 15 2.50 2.50 0.01 0.05 0.49 2.0% PRE -DA -16 16 0.02 5.09 5.10 0.01 0.05 0.49 2.1% PRE -DA -17 17 0.77 0.77 0.01 0.05 0.49 2.0% PRE -DA -18 18 0.01 3.51 3.51 0.01 0.05 0.49 2.1% PRE -DA -19 19 1.00 1.00 0.01 0.05 0.49 2.0% PRE -DA -20 20 0.15 4.56 4.71 0.02 0.06 0.50 3.2% BASIN 0.00 2.15 94.70 0.00 0.00 96.86 0.02 0.06 0.50 2.8% SUBTOTAL 0% 2% 98% 0% 0% 100% Kimley>>> Horn STANDARD FORM SF -2 TIME OF CONCENTRATION - PRE -CONSTRUCTION PRO. ECT NAME: Weld County - Cloudbreak - Michael Boulter South DATE: 7/6/2023 PROJECT NUMBER: CALCULATED CHECKED BY: BY: 196664000 JCH AJH FINAL SUB -BASIN INITIAL TRAVEL TIME Tc CHECK DATA (Ti) Tc (URBANIZED BASINS) TIME (T;) DESIGN AREA C5 (3) LENGTH (4) Ft SLOPE % (5) Ti Min. LENGTH SLOPE % (8) C, (9) Land (10) Surface Tt Min. COMP. (13) tc TOTAL TOTAL TOTAL Min. (17) Tc Min. C2 C5 C100 VEL fps (11) Ac (2) Ft. (7) LENGTH (14) SLOPE (15) IMP. (16) BASIN (1) (6) (12) On -Site Basins PRE -DA -01 3.021 0.05 498 1.1% 41.9 Tillage/Field 41.9 498 1.1% 2% NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 41.9 0.01 0.05 0.49 PRE -DA -02 3.233 0.05 500 0.6% 51.3 96 0.1% 5.0 Tillage/Field 0.1 12.9 64.2 596 0.5% 2% 64.2 0.01 0.05 0.49 PRE -DA -03 13.247 0.05 500 0.5% 54.8 1,067 0.2% 5.0 Tillage/Field 0.2 74.2 129.1 1567 0.3% 2% 129.1 0.01 0.05 0.49 409.4 0.02 0.06 0.50 PRE -DA -04 15.587 0.06 500 0.8% 46.7 1,124 0.0% 5.0 Tillage/Field 0.1 362.7 409.4 1624 0.2% 3% PRE -DA -05 9.241 0.06 500 1.6% 36.6 240 0.4% 5.0 Tillage/Field 0.3 12.2 48.7 740 1.2% 3% 48.7 0.02 0.06 0.50 PRE -DA -06 3.013 0.07 466 1.5% 36.1 Tillage/Field 36.1 466 1.5% 4% 36.1 0.02 0.07 0.50 PRE -DA -07 1.918 0.05 466 1.0% 41.5 Tillae/Field 41.5 466 1.0% 2% 41.5 0.01 0.05 0.49 PRE -DA -08 4.823 0.07 441 0.7% 45.1 Tillage/Field 45.1 441 0.7% 4% 45.1 0.03 0.07 0.50 PRE -DA -09 6.137 0.05 500 0.5% 52.7 204 0.0% 5.0 Tillage/Field 0.1 34.3 87.0 704 0.4% 2% 87.0 0.01 0.05 0.49 PRE -DA -10 7.840 0.05 500 0.5% 52.8 247 0.2% 5.0 Tillage/Field 0.2 17.8 70.5 747 0.4% 2% 70.5 0.01 0.05 0.49 PRE -DA -11 1.605 0.05 433 0.6% 47.5 Tillage/Field 47.5 433 0.6% 2% 47.5 0.01 0.05 0.49 40.6 0.02 0.06 0.50 PRE -DA -12 2.070 0.06 211 0.3% 40.6 Tillage/Field 40.6 211 0.3% 3% PRE -DA -13 4.321 0.11 500 0.6% 49.3 217 0.2% 5.0 Tillage/Field 0.2 15.7 65.0 717 0.5% 9% 65.0 0.06 0.11 0.52 PRE -DA -14 3.214 0.06 500 1.2% 40.4 114 0.5% 5.0 Tillae/Field 0.3 5.5 46.0 614 1.1% 3% 46.0 0.01 0.06 0.49 PRE -DA -15 2.496 0.05 293 0.2% 61.9 Tillage/Field 61.9 293 0.2% 2% 61.9 0.01 0.05 0.49 PRE -DA -16 5.101 0.05 500 1.2% 40.6 166 0.8% 5.0 Tillage/Field 0.5 6.1 46.8 666 1.1% 2% 46.8 0.01 0.05 0.49 PRE -DA -17 0.774 0.05 261 1.2% 28.9 Tillage/Field 28.9 261 1.2% 2% 28.9 0.01 0.05 0.49 PRE -DA -18 3.512 0.05 500 1.0% 43.1 361 0.3% 5.0 Tillage/Field 0.3 22.4 65.5 861 0.7% 2% 65.5 0.01 0.05 0.49 PRE -DA -19 0.996 0.05 321 0.9% 35.6 Tillage/Field 35.6 321 0.9% 2% 35.6 0.01 0.05 0.49 PRE -DA -20 4.708 0.06 484 0.7% 46.9 Tillage/Field 46.9 484 0.7% 3% 46.9 0.02 0.06 0.50 J� �y 4 0.39:11. x I:��-3s-yyC_ �k i_ _ _ t. (26 M _ � f { ' 6�f ' 6'5.� 1 'fy Y},y { A e�: : 60(141+ STANDARD FORM SF -3 Kimley>>> Horn STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT - PRE -CONSTRUCTION PRO.IF-F;CT NAME: Weld County - Cloudbreak - Michael Boulter South DATE' 7/6/2023 PRO.IF,CT NUMBER: 196664000 P1 (1 -Hour Rainfall) = 2.71 CALCULATED CHECKED BY: BY: JCH ASH REMARKS TRAVEL TIME DIRECT RUNOFF TOTAL RUNOFF STREET PIPE (u!ui) aj IGN VV(cfs I GT] rt) 4 v� ~ a )V` o�.4t •- �� 1 )E a o 0 OO � w ozcA .e� Il cl) A A P74 CID (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) On -Site Basins 1 PRE -DA -01 3.02 0.49 41.94 1.49 3.46 5.15 i 2 PRE -DA -02 3.23 0.49 64.21 1.59 2.62 4.16 3 PRE -DA -03 13.25 0.49 129.08 6.52 1.60 10.41 4 PRE -DA -04 15.59 0.50 409.44 7.74 0.67 5.19 5 PRE -DA -05 9.24 0.50 48.73 4.58 3.14 14.39 6 PRE -DA -06 3.01 0.50 36.12 1.51 3.80 5.73 7 PRE -DA -07 1.92 0.49 41.48 0.94 3.49 3.29 8 PRE -DA -08 4.82 0.50 45.08 2.42 3.31 8.00 9 PRE -DA -09 6.14 0.49 86.98 3.02 2.12 6.40 10 PRE -DA -10 7.84 0.49 70.51 3.87 2.45 9.49 11 PRE -DA -11 1.61 0.49 47.51 0.79 3.20 2.53 12 PRE -DA -12 2.07 0.50 40.61 1.03 3.53 3.63 13 PRE -DA -13 4.32 0.52 65.02 2.25 2.59 5.83 14 PRE -DA -14 3.21 0.49 46.00 1.59 3.26 5.19 15 PRE -DA -15 2.50 0.49 61.94 1.23 2.68 3.29 16 PRE -DA -16 5.10 0.49 46.76 2.51 3.23 8.12 17 PRE -DA -17 0.77 0.49 28.92 0.38 4.34 1.66 18 PRE -DA -18 3.51 0.49 65.49 1.73 2.58 4.46 19 PRE -DA -19 1.00 0.49 35.57 0.49 3.84 1.88 20 PRE -DA -20 4.71 0.50 46.94 2.34 3.22 7.54 Total 96.86 116.34 Kimley>>) Horn STANDARD FORM SF -1 RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION - POST -CONSTRUCTION PROJECT NAME: Weld County - Cloudbreak - Michael Boulter South 7/6/2023 PROJECT NUMBER: 196664000 CALCULATED BY: JCH CHECKED BY: AJH TYPE D SOIL VEGETATED FUTURE PAVED GRAVEL OPEN SPACE SOLAR PANEL COMMERCIAL LAND USE: AREA AREA AREA AREA AREA 2 -YEAR COEFF. 0.83 0.30 0.01 0.18 0.69 5 -YEAR COEFF. 0.84 0.36 0.05 0.24 0.72 100 -YEAR COEFF. 0.89 0.65 0.49 0.59 0.83 IMPERVIOUS % .. 100% 40% 2% 25% 85% DESIGN BASIN VEGETATED FUTURE Cc(2) Cc(5) Cc(100) Imp % DESIGN PAVED AREA GRAVEL AREA OPEN SPACE AREA SOLAR PANEL AREA COMMERCIAL AREA TOTAL AREA POINT (AC) (AC) (AC) (AC) (AC) (AC) On -Site Basins POST -DA -01 1 0.14 2.57 0.30 3.02 0.04 0.08 0.51 6.1% POST -DA -02 2 2.67 0.56 3.23 0.04 0.08 0.51 6.0% POST -DA -03 3 0.06 0.56 10.10 2.52 13.25 0.06 0.10 0.52 8.5% POST -DA -04 4 0.06 0.24 12.27 3.01 15.59 0.05 0.09 0.51 7.4% POST -DA -05 5 0.21 8.91 0.11 9.24 0.02 0.06 0.50 3.2% POST -DA -06 6 0.15 2.86 3.01 0.02 0.07 0.50 3.9% POST -DA -07 7 1.92 1.92 0.01 0.05 0.49 2.0% POST -DA -08 8 0.23 3.75 0.84 4.82 0.05 0.10 0.52 7.8% POST -DA -09 9 4.61 1.52 6.14 0.05 0.10 0.52 7.7% POST -DA -10 10 0.03 0.18 6.98 0.64 7.84 0.03 0.08 0.51 5.2% POST -DA -11 11 1.61 1.61 0.01 0.05 0.49 2.0% POST -DA -12 12 0.06 1.92 0.09 2.07 0.03 0.07 0.50 4.1% POST -DA -13 13 0.03 0.23 3.26 0.80 4.32 0.06 0.11 0.52 9.0% POST -DA -14 14 0.03 0.08 2.28 0.83 3.21 0.07 0.11 0.52 9.8% POST -DA -15 15 2.04 0.45 2.50 0.04 0.08 0.51 6.2% POST -DA -16 16 0.02 3.71 1.38 5.10 0.06 0.10 0.52 8.3% POST -DA -17 17 0.70 0.07 0.77 0.03 0.07 0.50 4.1% POST -DA -18 18 0.01 3.12 0.39 3.51 0.03 0.07 0.50 4.6% POST -DA -19 19 0.96 0.03 1.00 0.02 0.06 0.50 2.7°/o POST -DA -20 20 0.24 3.15 1.32 4.71 0.07 0.12 0.53 10.3% BASIN SUBTOTAL 0.22 2.35 79.41 14.88 0.00 96.86 0.04 0.09 0.51 6.7% 0% 2% 82% 15% 0% 100% Kimley>>> Horn STANDARD FORM SF -2 TIME OF CONCENTRATION - POST -CONSTRUCTION PROJECT NAME: Weld County - Cloudbreak - Michael Boulter South DATE: 7/6/2023 PROJECT NUMBER: 196664000 CALCULATED BY: JCH CHECKED BY: AJH INITIAL TRAVEL TIME Te CHECK FINAL Tc SUB -BASIN DATA (Ti) (URBANIZED BASINS) TIME (Ti) DESIGN BASIN AREA Ac (2) CS (3) SLOPE Ti Min. (6) SLOPE % (8) C, (9) Land Surface Min. (12) Tt COMP. (13) to TOTAL TOTAL TOTAL Min. (17) Tc Min. C2 C5 i C100 LENGTH LENGTH VEL Ft (4) % (5) Ft. (7) (10) fps (11) SLOPE (15) IMP. LENGTH (1) (14) (16) On -Site Basins POST -DA -01 3.021 0.08 498 1.1% 40.6 Heavy Meadow 40.6 498 1.1% 6% 33.1 33.1 0.04 0.08 0.51 POST -DA -02 3.233 0.08 500 0.6% 49.8 96 0.1% 2.5 Heavy Meadow 0.1 25.8 75.5 596 0.5% 6% NA 75.5 0.04 0.08 0.51 POST -DA -03 13.247 0.10 500 0.5% 52.2 1,067 0.2% 2.5 Heavy Meadow 0.1 148.5 200.6 1567 0.3% 8% NA 200.6 0.06 0.10 0.52 POST -DA -04 15.587 0.09 500 0.8% 45.1 1,124 0.0% 2.5 Heavy Meadow 0.0 725.4 770.6 1624 0.2% 7% NA 770.6 0.05 0.09 0.51 POST -DA -05 9.241 0.06 500 1.6% 36.5 240 0.4% 2.5 Heavy Meadow 0.2 24.3 60.8 740 1.2% 3% NA 60.8 0.02 0.06 0.50 POST -DA -06 3.013 0.07 466 1.5% 36.1 Heavy Meadow 36.1 466 1.5% 4% NA 36.1 0.02 0.07 0.50 POST -DA -07 1.918 0.05 466 1.0% 41.5 Heavy Meadow 41.5 466 1.0% 2% NA 41.5 0.01 0.05 0.49 POST -DA -08 4.823 0.10 441 0.7% 43.8 Heavy Meadow 43.8 441 0.7% 8% NA 43.8 0.05 0.10 0.52 POST -DA -09 6.137 0.10 500 0.5% 50.4 204 0.0% 2.5 Heavy Meadow 0.0 68.6 119.0 704 0.4% 8% NA 119.0 0.05 0.10 0.52 POST -DA -10 7.840 0.08 500 0.5% 51.6 247 0.2% 2.5 Heavy Meadow 0.1 35.5 87.1 747 0.4% 5% NA 87.1 0.03 0.08 0.51 POST -DA -11 1.605 0.05 433 0.6% 47.5 Heavy Meadow 47.5 433 0.6% 2% NA 47.5 0.01 0.05 0.49 POST -DA -12 2.070 0.07 211 0.3% 40.3 Heavy Meadow 40.3 211 0.3% 4% NA 40.3 0.03 0.07 0.50 POST -DA -13 4.321 0.11 500 0.6% 49.3 217 0.2% 2.5 Heavy Meadow 0.1 31.4 80.7 717 0.5% 9% NA 80.7 0.06 0.11 0.52 POST -DA -14 3.214 0.11 500 1.2% 38.2 114 0.5% 2.5 Heavy Meadow 0.2 11.1 49.3 614 1.1% 10% NA 49.3 0.07 0.11 0.52 POST -DA -15 2.496 0.08 293 0.2% 60.0 Heavy Meadow 60.0 293 0.2% 6% NA 60.0 0.04 0.08 0.51 POST -DA -16 5.101 0.10 500 1.2% 38.7 166 0.8% 2.5 Heavy Meadow 0.2 12.2 50.9 666 1.1% 8% NA 50.9 0.06 0.10 0.52 POST -DA -17 0.774 0.07 261 1.2% 28.5 Heavy Meadow 28.5 261 1.2% 4% NA 28.5 0.03 0.07 0.50 POST -DA -18 3.512 0.07 500 1.0% 42.3 361 0.3% 2.5 Heavy Meadow 0.1 44.8 87.0 861 0.7% 5% NA 87.0 0.03 0.07 0.50 POST -DA -19 0.996 0.06 321 0.9% 35.4 Heavy Meadow 35.4 321 0.9% 3% NA 35.4 0.02 0.06 0.50 POST -DA -20 4.708 0.12 484 0.7% 44.3 Heavy Meadow 44.3 484 0.7% 10% NA 44.3 0.07 0.12 0.53 #'I 4 O.39S1 — Cs r � .1:33 60K .\/S,601 , 60(141+ 9)41,17 STANDARD FORM SF -3 Kimle >>> Horn STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT - POST -CONSTRUCTION PROJECT NAME: Weld County - Cloudbreak - Michael Boulter South DAZE: 7/6/2023 PROJECT NUMBER: 196664000 P1 (1 -Hour Rainfall) = 2.71 CALCULATED BY: JCH CHECKED BY: AJH DIRECT RUNOFF TOTAL RUNOFF STREET TRAVEL TIME REMARKS PIPE tc (min) C*A(ac) o p.� tc(ma: a o ♦^, r-, . E v )` om co pa CY w w CA V) CE CA ....- a E• W� W' .� `- �, D-4 ��, Gov .5 W VD al g (1) I (2) I (3) I (4) I (5) I (6) I (7) I (8) I (9) 1(10)1(11) 1(12)1 (13) 1(14)1(15)1(16) (17) I (18) I (19) 1(20)1(21) (22) On -Site Basins 1 POST -DA -01 3.02 0.51 33.10 1.54 4.01 6.17 2 POST -DA -02 3.23 0.51 75.53 1.64 2.34 3.85 3 POST -DA -03 13.25 0.52 200.60 6.87 1.15 7.92 4 POST -DA -04 15.59 0.51 770.56 8.02 0.41 3.30 5 POST -DA -05 9.24 0.50 60.80 4.59 2.71 12.47 6 POST -DA -06 3.01 0.50 36.12 1.51 3.80 5.73 7 POST -DA -07 1.92 0.49 41.48 0.94 3.49 3.29 8 POST -DA -08 4.82 0.52 43.83 2.49 3.37 8.38 9 POST -DA -09 6.14 0.52 119.00 3.16 1.69 5.36 10 POST -DA -10 7.84 0.51 87.11 3.96 2.12 8.39 11 POST -DA -11 1.61 0.49 47.51 0.79 3.20 2.53 12 POST -DA -12 2.07 0.50 40.30 1.04 3.55 3.68 13 POST -DA -13 4.32 0.52 80.69 2.25 2.23 5.03 14 POST -DA -14 3.21 0.52 49.29 1.68 3.12 5.26 15 POST -DA -15 2.50 0.51 59.96 1.27 2.74 3.48 16 POST -DA -16 5.10 0.52 50.95 2.64 3.05 8.07 17 POST -DA -17 0.77 0.50 28.45 0.39 4.39 1.70 18 POST -DA -18 3.51 0.50 87.04 1.77 2.12 3.74 19 POST -DA -19 1.00 0.50 35.38 0.49 3.85 1.90 20 POST -DA -20 4.71 0.53 44.35 2.48 3.34 8.28 Total 96.86 108.52 Exhibit 7 — Hydrologic Response of Solar Farms Hydrologic Response of Solar Farms Lauren M. Cook, S.M.ASCE1; and Richard H. McCuen, M.ASCE2 Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. Abstract: Because of the benefits of solar energy, the number of solar farms is increasing; however, their hydrologic impacts have not been studied. The goal of this study was to determine the hydrologic effects of solar farms and examine whether or not storm -water management is needed to control runoff volumes and rates. A model of a solar farm was used to simulate runoff for two conditions: the pre- and postpaneled conditions. Using sensitivity analyses, modeling showed that the solar panels themselves did not have a significant effect on the runoff volumes, peaks, or times to peak. However, if the ground cover under the panels is gravel or bare ground, owing to design decisions or lack of maintenance, the peak discharge may increase significantly with storm -water management needed. In addition, the kinetic energy of the flow that drains from the panels was found to be greater than that of the rainfall, which could cause erosion at the base of the panels. Thus, it is recommended that the grass beneath the panels be well maintained or that a buffer strip be placed after the most downgradient row of panels. This study, along with design recommendations, can be used as a guide for the future design of solar farms. DOE 10.1061/(ASCE) HE.1943-5584.0000530. © 2013 American Society of Civil Engineers. CE Database subject headings: Hydrology; Land use; Solar power; Floods; Surface water; Runoff; Stormwater management. Author keywords: Hydrology; Land use change; Solar energy; Flooding; Surface water runoff; Storm -water management. Introduction Storm -water management practices are generally implemented to reverse the effects of land -cover changes that cause increases in volumes and rates of runoff. This is a concern posed for new types of land -cover change such as the solar farm. Solar energy is a re- newable energy source that is expected to increase in importance in the near future. Because solar farms require considerable land, it is necessary to understand the design of solar farms and their potential effect on erosion rates and storm runoff, especially the impact on offsite properties and receiving streams. These farms can vary in size from 8 ha (20 acres) in residential areas to 250 ha (600 acres) in areas where land is abundant. The solar panels are impervious to rain water; however, they are mounted on metal rods and placed over pervious land. In some cases, the area below the panel is paved or covered with gravel. Service roads are generally located between rows of panels. Altl- hough some panels are stationary, others are designed to move so that the angle of the panel varies with the angle of the sun. The angle can range, depending on the latitude, from 22° during the summer months to 74° during the winter months. In addition, the angle and direction can also change throughout the day. The issue posed is whether or not these rows of impervious panels will change the runoff characteristics of the site, specifically increase runoff volumes or peak discharge rates. If the increases are hydro- logically significant, storm -water management facilities may be needed. Additionally, it is possible that the velocity of water 1Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Maryland, College Park, MD 20742-3021. 2The Ben Dyer Professor, Dept. of Civil and Environmental Engineer- ing, Univ. of Maryland, College Park, MD 20742-3021 (corresponding author). E-mail: rhmccuen@eng.umd.edu Note. This manuscript was submitted on August 12, 2010; approved on October 20, 2011; published online on October 24, 2011. Discussion period open until October 1, 2013; separate discussions must be submitted for individual papers. This paper is part of the Journal of Hydrologic Engi- neering, Vol. 18, No. 5, May 1, 2013. © ASCE, ISSN 1084-069912013/5- 536-541/$25.00. draining from the edge of the panels is sufficient to cause erosion of the soil below the panels, especially where the maintenance roadways are bare ground. The outcome of this study provides guidance for assessing the hydrologic effects of solar farms, which is important to those who plan, design, and install arrays of solar panels. Those who design solar farms may need to provide for storm -water management. This study investigated the hydrologic effects of solar farms, assessed whether or not storm -water management might be needed, and if the velocity of the runoff from the panels could be sufficient to cause erosion of the soil below the panels. Model Development Solar farms are generally designed to maximize the amount of en- ergy produced per unit of land area, while still allowing space for maintenance. The hydrologic response of solar farms is not usually considered in design. Typically, the panels will be arrayed in long rows with separations between the rows to allow for maintenance vehicles. To model a typical layout, a unit width of one panel was assumed, with the length of the downgradient strip depending on the size of the farm. For example, a solar farm with 30 rows of 200 panels each could be modeled as a strip of 30 panels with space between the panels for maintenance vehicles. Rainwater that drains from the upper panel onto the ground will flow over the land under the 29 panels on the downgradient strip. Depending on the land cover, infiltration losses would be expected as the runoff flows to the bottom of the slope. To determine the effects that the solar panels have on runoff characteristics, a model of a solar farm was developed. Runoff in the form of sheet flow without the addition of the solar panels served as the prepaneled condition. The paneled condition assumed a downgradient series of cells with one solar panel per ground cell. Each cell was separated into three sections: wet, dry, and spacer. The dry section is that portion directly underneath the solar panel, unexposed directly to the rainfall. As the angle of the panel from the horizontal increases, more of the rain will fall directly onto 536 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. the ground; this section of the cell is referred to as the wet section. The spacer section is the area between the rows of panels used by maintenance vehicles. Fig. 1 is an image of two solar panels and the spacer section allotted for maintenance vehicles. Fig. 2 is a sche- matic of the wet, dry, and spacer sections with their respective di- mensions. In Fig. 1, tracks from the vehicles are visible on what is modeled within as the spacer section. When the solar panel is hori- zontal, then the length longitudinal to the direction that runoff will occur is the length of the dry and wet sections combined. Runoff from a dry section drains onto the downgradient spacer section. Runoff from the spacer section flows to the wet section of the next downgradient cell. Water that drains from a solar panel falls directly onto the spacer section of that cell. The length of the spacer section is constant. During a storm event, the loss rate was assumed constant for the 24-h storm be- cause a wet antecedent condition was assumed. The lengths of the wet and dry sections changed depending on the angle of the solar panel. The total length of the wet and dry sections was set Fig. 1. Maintenance or "spacer" section between two rows of solar panels (photo by John E. Showler, reprinted with permission) Ld Direction of Flow Wet section Dry section Spacer section 5 m 3.5 m Fig. 2. Wet, dry, and spacer sections of a single cell with lengths Lw, Ls, and Ld with the solar panel covering the dry section equal to the length of one horizontal solar panel, which was as- sumed to be 3.5 m. When a solar panel is horizontal, the dry section length would equal 3.5 m and the wet section length would be zero. In the paneled condition, the dry section does not receive direct rainfall because the rain first falls onto the solar panel then drains onto the spacer section. However, the dry section does infiltrate some of the runoff that comes from the upgradient wet section. The wet section was modeled similar to the spacer section with rain falling directly onto the section and assuming a constant loss rate. For the presolar panel condition, the spacer and wet sections are modeled the same as in the paneled condition; however, the cell does not include a dry section. In the prepaneled condition, rain falls directly onto the entire cell. When modeling the prepaneled condition, all cells receive rainfall at the same rate and are subject to losses. All other conditions were assumed to remain the same such that the prepaneled and paneled conditions can be compared. Rainfall was modeled after an natural resources conservation service (NRCS) Type II Storm (McCuen 2005) because it is an ac- curate representation of actual storms of varying characteristics that are imbedded in intensity -duration -frequency (IDF) curves. For each duration of interest, a dimensionless hyetograph was devel- oped using a time increment of 12 s over the duration of the storm (see Fig. 3). The depth of rainfall that corresponds to each storm magnitude was then multiplied by the dimensionless hyetograph. For a 2-h storm duration, depths of 40.6, 76.2, and 101.6 mm were used for the 2-, 25-, and 100 -year events. The 2- and 6-h duration hyetographs were developed using the center portion of the 24-h storm, with the rainfall depths established with the Baltimore IDF curve. The corresponding depths for a 6-h duration were 53.3, 106.7, and 132.1 mm, respectively. These magnitudes were chosen to give a range of storm conditions. During each time increment, the depth of rain is multiplied by the cell area to determine the volume of rain added to each section of each cell. This volume becomes the storage in each cell. Depend- ing on the soil group, a constant volume of losses was subtracted from the storage. The runoff velocity from a solar panel was calcu- lated using Manning's equation, with the hydraulic radius for sheet flow assumed to equal the depth of the storage on the panel (Bedient and Huber 2002). Similar assumptions were made to com- pute the velocities in each section of the surface sections. 20 40 60 Time (min) 80 100 120 Fig. 3. Dimensionless hyetograph of 2-h Type II storm JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 537 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. Runoff from one section to the next and then to the next downgradient cell was routed using the continuity of mass. The routing coefficient depended on the depth of flow in storage and the velocity of runoff. Flow was routed from the wet section to the dry section to the spacer section, with flow from the spacer section draining to the wet section of the next cell. Flow from the most downgradient cell was assumed to be the outflow. Discharge rates and volumes from the most downgradient cell were used for com- parisons between the prepaneled and paneled conditions. Alternative Model Scenarios To assess the effects of the different variables, a section of 30 cells, each with a solar panel, was assumed for the base model. Each cell was separated individually into wet, dry, and spacer sections. The area had a total ground length of 225 m with a ground slope of 1% and width of 5 m, which was the width of an average solar panel. The roughness coefficient (Engman 1986) for the silicon solar panel was assumed to be that of glass, 0.01. Roughness coefficients of 0.15 for grass and 0.02 for bare ground were also assumed. Loss rates of 0.5715 cm/h (0.225 in./h) and 0.254 cm/h (0.1 in./h) for B and C soils, respectively, were assumed. The prepaneled condition using the 2-h, 25 -year rainfall was assumed for the base condition, with each cell assumed to have a good grass cover condition. All other analyses were made assum- ing a paneled condition. For most scenarios, the runoff volumes and peak discharge rates from the paneled model were not significantly greater than those for the prepaneled condition. Over a total length of 225 m with 30 solar panels, the runoff increased by 0.26 m3, which was a difference of only 0.35%. The slight increase in runoff volume reflects the slightly higher velocities for the paneled con- dition. The peak discharge increased by 0.0013 m3, a change of only 0.31%. The time to peak was delayed by one time increment, i.e., 12 s. Inclusion of the panels did not have a significant hydro- logic impact. Storm Magnitude The effect of storm magnitude was investigated by changing the magnitude from a 25 -year storm to a 2 -year storm. For the 2 -year storm, the rainfall and runoff volumes decreased by approximately 50%. However, the runoff from the paneled watershed condition increased compared to the prepaneled condition by approximately the same volume as for the 25 -year analysis, 0.26 m3. This increase represents only a 0.78% increase in volume. The peak discharge and the time to peak did not change significantly. These results re- flect runoff from a good grass cover condition and indicated that the general conclusion of very minimal impacts was the same for dif- ferent storm magnitudes. Ground Slope The effect of the downgradient ground slope of the solar farm was also examined. The angle of the solar panels would influence the velocity of flows from the panels. As the ground slope was in- creased, the velocity of flow over the ground surface would be closer to that on the panels. This could cause an overall increase in discharge rates. The ground slope was changed from 1 to 5%, with all other conditions remaining the same as the base conditions. With the steeper incline, the volume of losses decreased from that for the 1% slope, which is to be expected because the faster velocity of the runoff would provide less opportunity for infiltra- tion. However, between the prepaneled and paneled conditions, the increase in runoff volume was less than 1%. The peak discharge and the time to peak did not change. Therefore, the greater ground slope did not significantly influence the response of the solar farm. Soil Type The effect of soil type on the runoff was also examined. The soil group was changed from B soil to C soil by varying the loss rate. As expected, owing to the higher loss rate for the C soil, the depths of runoff increased by approximately 7.5% with the C soil when com- pared with the volume for B soils. However, the runoff volume for the C soil condition only increased by 0.17% from the prepaneled condition to the paneled condition. In comparison with the B soil, a difference of 0.35% in volume resulted between the two conditions. Therefore, the soil group influenced the actual volumes and rates, but not the relative effect of the paneled condition when compared to the prepaneled condition. Panel Angle Because runoff velocities increase with slope, the effect of the angle of the solar panel on the hydrologic response was examined. Analy- ses were made for angles of 30° and 70° to test an average range from winter to summer. The hydrologic response for these angles was compared to that of the base condition angle of 45°. The other site conditions remained the same. The analyses showed that the angle of the panel had only a slight effect on runoff volumes and discharge rates. The lower angle of 30° was associated with an in- creased runoff volume, whereas the runoff volume decreased for the steeper angle of 70° when compared with the base condition of 45°. However, the differences (-0.5%) were very slight. Never- theless, these results indicate that, when the solar panel was closer to horizontal, i.e., at a lower angle, a larger difference in runoff volume occurred between the prepaneled and paneled conditions. These differences in the response result are from differences in loss rates. The peak discharge was also lower at the lower angle. At an angle of 30°, the peak discharge was slightly lower than at the higher angle of 70°. For the 2-h storm duration, the time to peak of the 30° angle was 2 min delayed from the time to peak of when the panel was positioned at a 70° angle, which reflects the longer travel times across the solar panels. Storm Duration To assess the effect of storm duration, analyses were made for 6-h storms, testing magnitudes for 2-, 25-, and 100 -year return periods, with the results compared with those for the 2-h rainfall events. The longer storm duration was tested to determine whether a longer du- ration storm would produce a different ratio of increase in runoff between the prepaneled and paneled conditions. When compared to runoff volumes from the 2-h storm, those for the 6-h storm were 34% greater in both the paneled and prepaneled cases. However, when comparing the prepaneled to the paneled condition, the in- crease in the runoff volume with the 6-h storm was less than 1% regardless of the return period. The peak discharge and the time -to -peak did not differ significantly between the two condi- tions. The trends in the hydrologic response of the solar farm did not vary with storm duration. Ground Cover The ground cover under the panels was assumed to be a native grass that received little maintenance. For some solar farms, the area be- neath the panel is covered in gravel or partially paved because the panels prevent the grass from receiving sunlight. Depending on the 538 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. volume of traffic, the spacer cell could be grass, patches of grass, or bare ground. Thus, it was necessary to determine whether or not these alternative ground -cover conditions would affect the runoff characteristics. This was accomplished by changing the Manning's n for the ground beneath the panels. The value of n under the pan- els, i.e., the dry section, was set to 0.015 for gravel, with the value for the spacer or maintenance section set to 0.02, i.e., bare ground. These can be compared to the base condition of a native grass (n = 0.15). A good cover should promote losses and delay the runoff. For the smoother surfaces, the velocity of the runoff increased and the losses decreased, which resulted in increasing runoff vol- umes. This occurred both when the ground cover under the panels was changed to gravel and when the cover in the spacer section was changed to bare ground. Owing to the higher velocities of the flow, runoff rates from the cells increased significantly such that it was necessary to reduce the computational time increment. Fig. 4(a) shows the hydrograph from a 30 -panel area with a time incre- ment of 12 s. With a time increment of 12 s, the water in each cell is discharged at the end of every time increment, which results in no attenuation of the flow; thus, the undulations shown in Fig. 4(a) result. The time increment was reduced to 3 s for the 2-h storm, which resulted in watershed smoothing and a rational hydrograph shape [Fig. 4(b)] . The results showed that the storm runoff 0.1 0.09 0.08 0.07 coE 0.06 0 0.05 co 0 0.04 0.03 (a) 0.02 0.01 0 0.07 0.06 0.05 U) 0.04 0.03 0.02 0.01 20 40 60 80 100 120 140 160 180 Time (min) 0 _ 0 (b) I Paneled Pre -paneled 4 - alb NC IS 20 40 60 80 100 120 140 160 Time (min) 180 200 Fig. 4. Hydrograph with time increment of (a) 12 s; (b) 3 s with Manning's n for bare ground increased by 7% from the grass -covered scenario to the scenario with gravel under the panel. The peak discharge increased by 73% for the gravel ground cover when compared with the grass cover without the panels. The time to peak was 10 min less with the gravel than with the grass, which reflects the effect of differ- ences in surface roughness and the resulting velocities. If maintenance vehicles used the spacer section regularly and the grass cover was not adequately maintained, the soil in the spacer section would be compacted and potentially the runoff volumes and rates would increase. Grass that is not maintained has the potential to become patchy and turn to bare ground. The grass under the panel may not get enough sunlight and die. Fig. 1 shows the result of the maintenance trucks frequently driving in the spacer section, which diminished the grass cover. The effect of the lack of solar farm maintenance on runoff char- acteristics was modeled by changing the Manning's n to a value of 0.02 for bare ground. In this scenario, the roughness coefficient for the ground under the panels, i.e., the dry section, as well as in the spacer cell was changed from grass covered to bare ground (n = 0.02).The effects were nearly identical to that of the gravel. The runoff volume increased by 7% from the grass -covered to the bare -ground condition. The peak discharge increased by 72% when compared with the grass -covered condition. The runoff for the bare - ground condition also resulted in an earlier time to peak by approx- imately 10 min. Two other conditions were also modeled, showing similar results. In the first scenario, gravel was placed directly under the panel, and healthy grass was placed in the spacer section, which mimics a possible design decision. Under these conditions, the peak discharge increased by 42%, and the volume of runoff increased by 4%, which suggests that storm -water management would be necessary if gravel is placed anywhere. Fig. 5 shows two solar panels from a solar farm in New Jersey. The bare ground between the panels can cause increased runoff rates and reductions in time of concentration, both of which could necessitate storm -water management. The final condition modeled involved the assumption of healthy grass beneath the panels and bare ground in the spacer section, which would simulate the con- dition of unmaintained grass resulting from vehicles that drive over the spacer section. Because the spacer section is 53% of the cell, the change in land cover to bare ground would reduce losses and de- crease runoff travel times, which would cause runoff to amass as it Fig. 5. Site showing the initiation of bare ground below the panels, which increases the potential for erosion (photo by John Showler, reprinted with permission) JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 539 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. moves downgradient. With the spacer section as bare ground, the peak discharge increased by 100%, which reflected the increases in volume and decrease in timing. These results illustrate the need for maintenance of the grass below and between the panels. Design Suggestions With well -maintained grass underneath the panels, the solar panels themselves do not have much effect on total volumes of the runoff or peak discharge rates. Although the panels are impervious, the rainwater that drains from the panels appears as runoff over the downgradient cells. Some of the runoff infiltrates. If the grass cover of a solar farm is not maintained, it can deteriorate either because of a lack of sunlight or maintenance vehicle traffic. In this case, the runoff characteristics can change significantly with both runoff rates and volumes increasing by significant amounts. In addition, if gravel or pavement is placed underneath the panels, this can also contribute to a significant increase in the hydrologic response. If bare ground is foreseen to be a problem or gravel is to be placed under the panels to prevent erosion, it is necessary to counteract the excess runoff using some form of storm -water man- agement. A simple practice that can be implemented is a buffer strip (Dabney et al. 2006) at the downgradient end of the solar farm. The buffer strip length must be sufficient to return the runoff character- istics with the panels to those of runoff experienced before the gravel and panels were installed. Alternatively, a detention basin can be installed. A buffer strip was modeled along with the panels. For approxi- mately every 200 m of panels, or 29 cells, the buffer must be 5 cells long (or 35 m) to reduce the runoff volume to that which occurred before the panels were added. Even if a gravel base is not placed under the panels, the inclusion of a buffer strip may be a good prac- tice when grass maintenance is not a top funding priority. Fig. 6 shows the peak discharge from the graveled surface versus the length of the buffer needed to keep the discharge to prepaneled peak rate. Water draining from a solar panel can increase the potential for erosion of the spacer section. If the spacer section is bare ground, the high kinetic energy of water draining from the panel can cause soil detachment and transport (Garde and Raju 1977; Beuselinck et al. 2002). The amount and risk of erosion was modeled using the velocity of water coming off a solar panel compared with the velocity and intensity of the rainwater. The velocity of panel 0.07 0.06 0.05 M 0.04 0 11 0.03 o_ 0.02 0.01 5 10 15 20 25 Length of buffer (m) Pre -paneled peak Q Peak Q vs. buffer length - 30 35 40 Fig. 6. Peak discharge over gravel compared with buffer length runoff was calculated using Manning's equation, and the velocity of falling rainwater was calculated using the following: Vt = 120 d).35 (1) where d,. = diameter of a raindrop, assumed to be 1 mm. The re- lationship between kinetic energy and rainfall intensity is Ke = 916 + 3301og10 i (2) where i = rainfall intensity (in./h) and Ke = kinetic energy (ft -tons per ac -in. of rain) of rain falling onto the wet section and the panel, as well as the water flowing off of the end of the panel (Wischmeier and Smith 1978). The kinetic energy (Salles et al. 2002) of the rain- fall was greater than that coming off the panel, but the area under the panel (i.e., the product of the length, width, and cosine of the panel angle) is greater than the area under the edge of the panel where the water drains from the panel onto the ground. Thus, dividing the kinetic energy by the respective areas gives a more accurate representation of the kinetic energy experienced by the soil. The energy of the water draining from the panel onto the ground can be nearly 10 times greater than the rain itself falling onto the ground area. If the solar panel runoff falls onto an un- sealed soil, considerable detachment can result (Motha et al. 2004). Thus, because of the increased kinetic energy, it is pos- sible that the soil is much more prone to erosion with the panels than without. Where panels are installed, methods of erosion control should be included in the design. Conclusions Solar farms are the energy generators of the future; thus, it is im- portant to determine the environmental and hydrologic effects of these farms, both existing and proposed. A model was created to simulate storm -water runoff over a land surface without panels and then with solar panels added. Various sensitivity analyses were conducted including changing the storm duration and volume, soil type, ground slope, panel angle, and ground cover to determine the effect that each of these factors would have on the volumes and peak discharge rates of the runoff. The addition of solar panels over a grassy field does not have much of an effect on the volume of runoff, the peak discharge, nor the time to peak. With each analysis, the runoff volume increased slightly but not enough to require storm -water management facili- ties. However, when the land -cover type was changed under the panels, the hydrologic response changed significantly. When gravel or pavement was placed under the panels, with the spacer section left as patchy grass or bare ground, the volume of the runoff in- creased significantly and the peak discharge increased by approx- imately 100%. This was also the result when the entire cell was assumed to be bare ground. The potential for erosion of the soil at the base of the solar pan- els was also studied. It was determined that the kinetic energy of the water draining from the solar panel could be as much as 10 times greater than that of rainfall. Thus, because the energy of the water draining from the panels is much higher, it is very possible that soil below the base of the solar panel could erode owing to the concen- trated flow of water off the panel, especially if there is bare ground in the spacer section of the cell. If necessary, erosion control meth- ods should be used. Bare ground beneath the panels and in the spacer section is a realistic possibility (see Figs. 1 and 5). Thus, a good, well - maintained grass cover beneath the panels and in the spacer section is highly recommended. If gravel, pavement, or bare ground is 540 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. deemed unavoidable below the panels or in the spacer section, it may necessary to add a buffer section to control the excess runoff volume and ensure adequate losses. If these simple measures are taken, solar farms will not have an adverse hydrologic impact from excess runoff or contribute eroded soil particles to receiving streams and waterways. Acknowledgments The authors appreciate the photographs (Figs. 1 and 5) of Ortho Clinical Diagnostics, 1001 Route 202, North Raritan, New Jersey, 08869, provided by John E. Showler, Environmental Scientist, New Jersey Department of Agriculture. The extensive comments of reviewers resulted in an improved paper. References Bedient, P. B., and Huber, W. C. (2002). Hydrology and,floodplain analy- sis, Prentice -Hall, Upper Saddle River, NJ. Beuselinck, L., Govers, G., Hairsince, P. B., Sander, G. C., and Breynaert, M. (2002). "The influence of rainfall on sediment transport by overland flow over areas of net deposition." J. Hydrol., 257(1-4), 145-163. Dabney, S. M., Moore, M. T., and Locke, M. A. (2006). "Integrated man- agement of in -field, edge -of -field, and after -field buffers." J. Amer. Water Resour. Assoc., 42(1), 15-24. Engman, E. T. (1986). "Roughness coefficients for routing surface runoff." J. Irrig. Drain. Eng., 112(1), 39-53. Garde, R. J., and Raju, K. G. (1977). Mechanics of sediment transportation and alluvial stream problems, Wiley, New York. McCuen, R. H. (2005). Hydrologic analysis and design, 3rd Ed., Pearson/ Prentice -Hall, Upper Saddle River, NJ. Motha, J. A., Wallbrink, P. J., Hairsine, P. B., and Grayson, R. B. (2004). "Unsealed roads as suspended sediment sources in agricultural catch- ment in south-eastern Australia." J. Hydrol., 286(1-4), 1-18. Salles, C., Poesen, J., and Sempere-Torres, D. (2002). "Kinetic energy of rain and its functional relationship with intensity." J. Hydrol., 257(1-4), 256-270. Wischmeier, W. H., and Smith, D. D. (1978). Predicting rainfall erosion losses: A guide to conservation planning, USDA Handbook 537, U.S. Government Printing Office, Washington, DC. JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 541 J. Hydrol. Eng. 2013.18:536-541. Kimley >) Horn PRELIMINARY DRAINAGE REPORT Michael Boulter - Solar Weld County Case # TBD Northeast of the intersection of Weld County Rd 44 and Weld County Road 45 Weld County, CO Prepared by: Kimley-Horn Inc. 1125 17th Street, Suite 1400 Denver, CO 80202 Contact: Adam Harrison, P.E. Phone: (303) 228-2311 Prepared on: May 09, 2023 Michael Boulter Solar — Weld County, CO May 2023 Page 1 Kimley >) Horn TABLE OF CONTENTS 1. PROJECT DESCRIPTION & SCOPE OF WORK 3 1.1. Project Location 3 1.2. Nearby Water Features & Ownership 4 1.3. Report & Analysis Methodologies 4 1.4. Stormwater Management 5 2. CONCLUSION 5 EXHIBITS Exhibit 1 - FEMA Firm Map Exhibit 2 - NRCS Report Exhibit 3 — NOAA Rainfall Data Exhibit 4 — Pre -Development Drainage Area Map Exhibit 5 — Post -Development Drainage Area Map Exhibit 6 — Hydrologic Calculations & Detention/WQCV Calculations Exhibit 7 — Hydrologic Response of Solar Farms Michael Boulter Solar — Weld County, CO May 2023 Page 2 Kimley >) Horn 1. PROJECT DESCRIPTION & SCOPE OF WORK The development is a proposed 10.0-MWac Solar power generating facility located in Weld County, CO. The solar power generating facility will consist of rows of Photovoltaic Solar Modules, gravel access driveways, associated electrical equipment, underground utilities, and a substation (by others). Solar modules will be mounted on piles and elevated above the ground as to preserve the existing underlying soil and allow for revegetation and infiltration. The project will be surrounded by a perimeter fence. Ground area within the limits of development that is not occupied by gravel roads or foundations will be seeded to establish permanent vegetation. This drainage narrative is intended to provide Weld County with preliminary information regarding the drainage and land disturbance activities related to the proposed Michael Boulter South Solar, small scale solar facility (Project). The project will be designed and will be constructed and maintained in a manner that minimizes storm water related impacts, in accordance with Weld County drainage criteria. Project name, Property Address and Weld County Parcel No. Michael Boulter Solar, 22001-22999 WCR 44 Weld 80645, Parcel No. 105514300030 Developer/Owner CloudBreak Energy Partners, LLC, 218 S. 3rd Street Sterling, CO 80751 Urbanizing/Non-Urbanizing This site is located more than a quarter mile away from the nearest Weld County municipal boundary and is classified as "Non -Urbanizing". Therefore, detention ponds designed for this site would be sized using 10 -year runoff rates. 1.1. Project Location The existing site subject property is a parcel of 152.6 acres. The project is located on approximately 96.86 acres of lightly vegetated land. The project is located south east of La Salle, within Weld County. The site is bounded to the north by property owned by Michael Boulter Farms LLC (Parcel 105514200025), to the east by parcel 105514000014 owned by the city of Broomfield, to the west by WCR 45 and to the south by WCR 44. Section Township Range Property is located within a portion of the south west quarter of Section 14, Township 4 North, Range 65 West of the 6th P.M., Weld County, Colorado. Per FEMA Map Panels 08123C1750E effective 01/20/2016, none of the development area is within a flood hazard area. (Refer to Exhibit 1 for FEMA Map). The NRCS Report dated 04/28/2023, concludes that onsite soils consist mostly of Aquolls and Aquepts, Vona sandy loam and Vona loamy sand, and Otero sandy loam that classify as hydrologic soil groups (HSG) type A and D. The site was modeled using all type D soils. For additional detail, refer to Exhibit 2 for the NRCS Report. Michael Boulter Solar — Weld County, CO May 2023 Page 3 Kimley >) Horn 1.2. Nearby Water Features & Ownership In the existing condition, a majority of the site drains to the surrounding agricultural and lightly vegetated property of the same parcel number as the project site. The nearest water feature is Gilmore Ditch approximately 0.7 miles east of the project area. Gilmore Ditch is the receiving water of the project site. The existing drainage patterns will be maintained in the proposed condition. Refer to Exhibit 4 and Exhibit 5 for the Pre and Post -Development Drainage Area Maps. 1.3. Report & Analysis Methodologies This report evaluates the pre and post development runoff characteristics of the development (including solar facility footprint and access drive) and addresses the stormwater requirements of Weld County and the state of Colorado. Hydrologic Design Criteria The table below notes the hydrologic design criteria used in the analysis. Parameter Value Unit Reference Time of Concentration, Tc - min. Exhibit 6 Runoff Coefficient, C - - MHFD Criteria Manual, Chapter 6, Table 6-4 1 -hr Point Rainfall, P1 (100 -Year) 2.71 Inches NOAA Rainfall Data (Exhibit 3) Storm Runoff, Q - cfs Q = CIA Basin Conditions The drainage areas of the site are shown for the site as Pre -construction (Exhibit 4) and Post - construction (Exhibit 5). Pre -construction drainage basins were analyzed to calculate the peak historic runoff for the design storm. Proposed post construction drainage basins were analyzed to calculate the peak runoff for the design storm using an impervious percentage of 2.8% (see Exhibit 6 for the imperviousness summary). The tracking solar panels are not classified as an impervious surface because precipitation falling on the solar panels will shed onto the undisturbed vegetated surface below. The existing drainage basins 1,3,5,8,9,10,12,13,14,16, and 20 under existing conditions currently pond across the site. The projects proposed conditions will utilize grading and storm infrastructure to create positive drainage of the entire site. Stormwater Runoff The stormwater runoff for existing and proposed conditions is calculated utilizing the Rational Method. The 100 -year, 1 -hour storm event was analyzed for pre and post -construction drainage basins. The flow path for the basins can be seen in Exhibits 4 & 5. The time of concentration to the point of accumulation was calculated using MHFD equations and can be found in Exhibit 6. The Runoff Coefficients are also included in Exhibit 6. The precipitation data used for the 100 - year, 1 -hour storm event is based on NOAA rainfall data from the project site (Exhibit 3). A summary of the rational calculation findings is shown in the table below. Existing Proposed Area 96.86 ac 96.86 ac Imperviousness 2.8 °/0 3.1 Qioo 155.7 cfs 156.3 cfs Michael Boulter Solar — Weld County, CO May 2023 Page 4 Kimley >) Horn 1.4. Stormwater Management A study published in the Journal of Hydrologic Engineering researched the hydrologic impacts of utility scale solar generating facilities. The study utilized a model to simulate runoff from pre -and post -solar panel conditions. The study concluded that the solar panels themselves have little to no impact on runoff volumes or rates. Rainfall losses, most notably infiltration, are not impacted by the solar panels. Rainfall that falls directly on a solar panel runs to the pervious areas around and under the surrounding panels. Refer to Exhibit 7 for the study published in the Journal of Hydrologic Engineering. Under developed conditions, runoff will follow existing drainage patterns and will not significantly increase peak flows (increases from 155.7 cfs to 156.3 cfs in the 100-year,1-hour storm event). 2. CONCLUSION The following list summarizes key components of the Project and findings related to land disturbance and storm water impacts. • Installation of the solar facility will temporarily disturb the ground surface within the 96.86 acre Project area, but won't require clearing and grubbing of vegetation or grading, except for concrete equipment pads and gravel access drive installations. • The areas considered impervious (100 percent impervious 9,619 sq ft concrete pads) or semi -impervious (40 percent impervious 102,366 sf gravel access drive) total 2.35 acres or 2.42% of the project area. This increase in imperviousness is negligible as it relates to total stormwater runoff for the planned solar development. • Under existing conditions, the peak flow from the site area for the 100 yr — 1 hr storm event is 155.7 cfs. • Under developed conditions, the peak flow from the site area for the 100 yr — 1 hr storm event is 156.3 cfs. • Installation of the solar facility is not expected to impact existing drainage patterns or flow rates on or around the project site. Runoff water quality will not be impacted by the solar facility components. • The project design will adequately protect public health, safety and general welfare and have no adverse effects on Weld County right-of-way or offsite properties. As noted above, a study published in the Journal of Hydrologic Engineering (Exhibit 7) researched the hydrologic impacts of utility scale solar generating facilities. The study utilized a model to simulate runoff from pre -development and post -development solar panel conditions. The study concluded that the solar panels themselves have little to no impact on runoff volumes or rates. Rainfall losses, most notably infiltration, are not impacted by the solar panels. Rainfall that falls directly on a solar panel runs to the pervious areas around and under the surrounding panels. Grading is proposed with minimal changes to the existing site drainage patterns and onsite access roads will be made of gravel. Based on the proposed improvements on the project site, the findings of the above referenced study, and the calculations included within this report, increases in runoff will be negligible. Therefore, permanent stormwater detention and water quality facilities are not proposed with the project. Michael Boulter Solar — Weld County, CO May 2023 Page 5 Kimley >) Horn We trust that the information provided is acceptable and complete for preliminary site plan review drainage report requirements. Please let us know if you have any questions or need additional information. KIMLEY-HORN LEY -HORN AND ASSOCIATES, INC. Adam Harrison, PE Project Manager Michael Boulter Solar — Weld County, CO May 2023 Page 6 Exhibit 1 — FEMA Firm Map National Flood Hazard Layer FIRMette FEMA Legend 104°38'23"W 40°18'44"N 104°37'46"W 40°18'16"N SLVEIJ) I:_ 0 250 500 1,000 1,500 08.12_ 1/20/2016 Not Printed T4N F 65W S23 2,000 Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 PROJECT AREA J saant Feet 1:6,000 SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V. A99 With BFE or Depth Zone AE, AO, AN, VE, AR Regulatory Floodway OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Future Conditions 1% Annual Chance Flood Hazard Area with Reduced Flood Risk due to Levee. See Notes. Zone X Area with Flood Risk due to Levee Zone D NO SCREEN Area of Minimal Flood Hazard zone x Effective LOM Rs Area of Undetermined Flood Hazard Zone D - Channel, Culvert, or Storm Sewer milli Levee, Dike, or Floodwall 20.2 Cross Sections with 1% Annual Chance 1765 Water Surface Elevation 8 - - - - Coastal Transect .� ,1 n Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary - - - Coastal Transect Baseline Profile Baseline Hydrographic Feature Digital Data Available No Digital Data Available Unmapped The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 4/28/2023 at 10:46 AM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Exhibit 2 — NRCS Report 40° 18' 42" N S 40° 18' 16" N S 104° 38' 32" W 104° 38' 32" W Hydrologic Soil Group —Weld County, Colorado, Southern Part 530500 530600 530700 530800 530900 Map Scale: 1:5,630 if printed on A landscape (11" x 8.5") sheet Meters 0 50 100 200 300 531000 531100 531200 Feet 0 250 500 1000 1500 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 531600 I I I 531300 531400 531500 531600 104° 37' 39" W 104° 37 39" W co Co 40° 18' 42" N 40° 18' 16" N ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 4/28/2023 Page 1 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part MAP LEGEND Area of Interest (AO!) Area of Interest (A01) ) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines 0 0 A A/D B B/D C C/D D Not rated or not available Soil Rating Points II O O O A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background ,; Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 21, Sep 1, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 8, 2021 Jun 12, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 4/28/2023 Page 2 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 4 Aquolls flooded and Aquepts, D 57.5 58.7% 50 Otero sandy loam, percent slopes 0 to 1 A 15.9 16.3% 70 Valent sand, percent slopes 3 to 9 A 19.9 20.3% 72 Vona percent loamy slopes sand, 0 to 3 A 1.5 1.5% 76 Vona sandy loam, percent slopes 1 to 3 A 3.2 3.3% Totals for Area of Interest 98.0 100.0% e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/28/2023 Page 3 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and CID). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, BID, or CID), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie -break Rule: Higher e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/28/2023 Page 4of4 Exhibit 3 — NOAA Rainfall Data NOAA Atlas 14, Volume 8, Version 2 Location name: La Salle, Colorado, USA* Latitude: 40.3066°, Longitude: -104.6379° Elevation: 4700.91 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES V 1 I LI1111 - �C S U+` 'MFq rp Or Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration 5 -min J 10 -min J 1 15 -min 30 -min 60 -min 2 -hr 3 -hr 6 -hr 12 -hr 24 -hr 2 -day 3 -day 4 -day 7 -day 10 -day 20 -day 30 -day 45 -day 60 -day Average recurrence interval (years) 0.242 (0.198-0.299) 0.355 (0.291-0.437) 0.433 (0.354-0.533) 0.580 (0.475-0.715) 0.720 (0.590-0.887) 0.859 (0.709-1.05) 0.941 (0.780-1.15) 1.09 (0.907-1.31) 1.27 (1.07-1.52) 1.51 (1.28-1.79) 1.73 (1.48-2.04) 1.90 (1.62-2.22) 2.02 (1.74-2.36) 2.30 (1.99-2.67) 2.55 (2.21-2.93) 3.25 (2.85-3.71) 3.82 (3.36-4.34) 0.293 (0.240-0.362) 0.429 (0.351-0.530) 0.523 (0.428-0.646) 0.700 (0.573-0.864) 0.856 (0.700-1.06) 1.01 (0.833-1.24) 1.10 [(0.906-1.33) 1.27 (1.06-1.53) 1.51 (1.26-1.80) 1.78 1.50-2.11) 2.06 (1.75-2.42) 2.22 1.90-2.60) 2.36 (2.02-2.75) 2.69 (2.32-3.11) 2.97 (2.58-3.43) 3.76 (3.29-4.29) 4.39 (3.86-4.99) 4.51 (3.98-5.09) 5.06 (4.48-5.70) 5.18 (4.57-5.85) 5.84 (5.17-6.58) 5 0.390 (0.318-0.483) 0.571 (0.466-0.708) 0.697 (0.568-0.863) 0.932 (0.759-1.15) 1.13 (0.920-1.40) 1.33 (1.09-1.63) 1.42 (1.17-1.74) 1.65 (1.37-2.00) 10 0.484 (0.392-0.603) 0.709 (0.574-0.882) 0.865 (0.700-1.08) 1.16 (0.936-1.44) 1.40 1.14-1.75) 1.65 1.35-2.04) 1.77 (1.45-2.17) 2.04 1.68-2.48) 1.95 1.63-2.34) 2.38 (1.97-2.87) 2.27 2.72 (1.91-2.70) (2.28-3.26) 2.62 II 3.13 2.23-3.10)JL (2.64-3.71) 2.80 I 3.30 2.38-3.28) _ [(2.80-3.90) 2.94 3.45 (2.51-3.43)J (2.93-4.05) 3.34 if 3.89 (2.87-3.87) IL (3.33-4.54) 3.68 (3.18-4.25) 4.58 (3.98-5.24) 5.30 (4.64-6.05) 6.24 (5.49-7.08) 7.06 (6.22-7.97) 4.27 (3.67-4.96) 5.24 (4.54-6.03) 25 0.633 (0.500-0.845) 0.927 (0.732-1.24) 1.13 (0.892-1.51) 1.52 (1.20-2.03) 1.85 (1.47-2.49) 2.19 (1.76-2.93) 2.36 (1.90-3.14) 2.68 (2.17-3.52) 3.05 (2.47-3.92) 3.43 (2.79-4.34) 3.87 (3.16-4.81) 4.05 (3.32-5.01) J 4.20 (3.46-5.17) 4.68 J (3.86-5.68) 5.09 (4.21-6.12) 6.04 (5.25-6.92) 7.09 (6.19-8.08) 8.02 (7.03-9.10) 6.14 (5.11-7.28) 7.03 (5.87-8.27) 8.21 (6.88-9.59) 9.28 (7.79-10.8) 50 0.763 (0.582-1.03) 1.12 (0.851-1.51) 1.36 (1.04-1.84) 1.83 (1.40-2.47) 2.26 (1.72-3.05) 2.68 (2.07-3.61) 100 0.907 (0.661-1.26) 1.33 (0.969-1.84) 1.62 (1.18-2.24) 2.18 (1.59-3.02) 2.71 (1.98-3.77) 3.24 (2.39-4.47) 2.89 (2.25-3.88) 3.26 (2.55-4.31) 3.63 (2.85-4.72) 4.02 (3.18-5.15) 4.48 (3.55-5.64) 4.67 (3.72-5.85) 4.82 (3.86-6.01) 5.31 (4.26-6.54) 5.73 (4.62-7.00) 6.83 (5.54-8.23) 7.77 (6.33-9.29) (7.9.04 40-10.7) 10.2 (8.37-12.0) 3.50 (2.60-4.82) 3.91 (2.93-5.31) 4.28 (3.22-5.71) 4.67 (3.54-6.15) 5.12 (3.90-6.63) 5.32 (4.07-6.84) 5.47 (4.21-7.01) 5.95 (4.60-7.53) 6.38 (4.95-8.00) 7.50 (5.87-9.28) 8.49 (6.67-10.4) 9.83 (7.76-12.0) 11.1 (8.75-13.4) 200 1.07 (0.739-1.52) 1.56 1.08-2.23) 1.91 (1.32-2.72) 2.57 (1.78-3.67) 3.22 (2.23-4.61) 3.86 (2.71-5.49) 4.20 (2.96-5.94) 4.65 (3.31-6.50) 500 1000 1.30 (0.857-1.91) 1.90 (1.25-2.80) 2.32 (1.53-3.41) 3.14 (2.07-4.61) 1.49 (0.947-2.20) 2.18 (1.39-3.23) 2.66 (1.69-3.93) 3.60 (2.29-5.32) 3.97 2.62-5.84) 4.80 (3.20-7.01) 4.59 (2.92-6.78) 5.58 (3.58-8.15) 5.24 (3.52-7.61) 5.75 (3.90-8.26) 4.99 I 6.0252) 3.57-6.85)J 5.38 (3.89-7.30) 5.81 (4.22-7.75) 6.01 (4.39-7.97)J 6.17 (4.53-8.14) 6.63 (4.89-8.64) 7.04 (5.21-9.09) 8.17 (6.11-10.4)]L 9.20 (6.90-11.6)J 10.6 (8.00-13.3) 11.9 (8.99-14.8) 6.40 (4.42-8.94) 6.77 (4.70-9.31) C 6.98 (4.88-9.54) 7.14 (5.01-9.71) 7.55 (5.33-10.1) 7.92 (5.62-10.5) 9.05 (6.48-11.9) 10.1 (7.27-13.2) 11.6 (8.37-14.9) 12.9 (9.36-16.6) 6.11 (3.94-8.88) 6.67 (4.35-9.58) 6.87 (4.53-9.78) 7.24 (4.82-10.2) 7.54 (5.07-10.5) 7.76 (5.25-10.7) 7.92 (5.38-10.9) 8.27 (5.67-11.3) 8.59 (5.93-11.6) 9.70 (6.76-13.0) 10.8 (7.55-14.3) 12.2 (8.65-16.2) 13.6 (9.65-17.9) Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical PDS-based depth -duration -frequency (DDF) curves Latitude: 403066°r Longitude: -104.6379° Precipitation depth (in) 14 12 10 14 12 10 1 a 1 i 1 1 1 1 I I I 1 1 1 I I I 1 I I I I e e I 1 I 1 I I I I 1 a a 1 I 1 1 1 1 1 1 1 a 1 1 a a I 1 I 1 I I I I I I 1 1 1 1 I I I I 1 a a a a a a a a 1 1 1 1 1 Y a .... . .1. • as . . Pr . . . . . L . . _ . . ,.I _ . .I .. _ .a .. _ . ../1 . _ ..1_ _ . . . L. . . . .. I. . _ .. I. a a e I 1 4 Y a • • . • a a a a • a • • a a a I 1 I I 1 1 1 a I 1 I 1 1 1 I I • • I I • • • I P I P I I • • 1 1 1 1 1 1 1 a 1 1 a 1 a a 1 1 V I I I I I e t e a IF I I a I a a 1 a a a a 1 a a a a a a a a a a s i a a i i i a 1 • a a if ! a 1 1 I I I I 1 1 t t t . 1 a I p . I vl al a 1 1 1 1 1 a e e e I I I I e 1 e e e I e I I I • • • 1t I I I I 1 1 1 I I 1 a I i I I / 1 1 e g a I a e e • • e e -- . —— t 1 I I I I I I a i -_ _ 1• — • I I a 1 I a a a a 1 ....-.a t Y Y- e a . Y 1 1 a 1 a � a a e e 1 a 1 1 a a I ....rears— I I I 5 • I Y • - 'J • • • - - i 1 1 a 1 1 Y 1 - 1 1 1 a a a 1 I a I 1 a I a t - i { • I I 1 ! 1 f e I I I I I I I t ! t ! I i r - — — — — — — — — — • t •. _ — — — _ _ _ _ Y— — 1 — '. — — I— — —I•_ .. — — I 1 1 I 1 a i - 1 1 a i 1 a e e e e I I a a I • e Y 1 1 a a 1 a e e T - ! a�fi II ! ! e e e a 1 I C c e t'•J 1 _ LA 5 10 25 50 100 200 NOM Atlas 14, Volume 8, Version 2 C 1•D 1 1 Duration :- = .�•i 1 i3 111 a I to I I N ICIrzi Average recurrence interval (years) ro Co rp V V V t 6 u1 6 N f #Le 500 1000 Created {GMT): Mon Feb 6 20:20:13 2023 Back to Top Maps & aerials Small scale terrain Average recurrence interval (years) 1 2 5' 10 25 50 100 200 500 1 000 Duration 5-mp — 2 -day 10-mon — 3 -day 15' -min — 4 -day 30 -min — 7 -day 6 Din - 10 -day 2 -hr — 2.0 -day 34',r — 30 -day. 5 -hr — 45 -day .112 -ht 50 -day 24 -hr Nastesiesturiset Lmna'f?'1 R e c ervo l,r -, SE 3km 2mi EASTON VA L El VIEW avhc: ARPO,R Elba - _; A Large scale terrain Large scale map S Large scale aerial Cheyenne - Ireeley ■I L'? ngm ln Boulder 100km 60mi -11 er Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?: HDSC.Questions@noaa.gov Disclaimer Exhibit 4 — Pre -Development Drainage Area Map \DIS. ..I`SOW\AW.O']a q, YY�Y�OIaJ Wfrld Ew^'�=Iato\1/rt1•a. 0aa11✓ - Lo,'..�\C•)tI\) (.n V...\fn• DiAMA'ui YAP i44t MY Ilas. Jac. 5/.1�)Q23 V. 11 aM if lawn ,a r.. ax I sta SalY.nlu�a. ui as an * .t 1s. is* a. soli L nab salt.. oil masa Y\ rata as- a W. nail alai a at l..ia Midi. altssal a• ar)Y atrial* a NS alga t a. a .al. a na.•)r..ou,. a L. 5 s...l ) m x L T 6 • e.a_r. S 111111> 80 80 88 / ` 9. C . 'OO • A a llama SINN -r' • ♦ f..- ♦ JY J r / if fJ --® a — / a SENN a ' tc tia. \to It; :2_? lirilde 411% vi vk g iii aP&Lp€ glAP It* Ws ari o r •1.3 � a NC LL 41?; s!i sa ••; f ' • 7 c J f sons own rIETS1 -— — ' Anis r at% INS ♦O / / 'S IDA • It 2 w g A a • • 4 N • • *174 • S .4 0 / N. • 1 I I 1 i 4 r g, • m C) m Z C a • ;0811 T i 1 g 141 §24 BOULTER — CLOUDBREAK WELD COUNTY, COLORADO USE SY SPECIAL REVIEW PRE -CONSTRUCTION DRAINAGE MAP IROS 8J 3 ttal? Kimleyx> Horn t'2.623 V.WI t-4041 ...NJ A S%UOA TES. A:. 'U5 11 P. Silhl S.A • ADO Urea, Coloroas W731 (SOS) ?J6 1500 NO 41. V1901 B" JA Exhibit 5 — Post -Development Drainage Area Map a�OE\-C rI��CIw/h��fl4flO 0_wY Lars f p[r11woyHcror IIw11r - L.'' C�']O\i fr.a1�\F [S - OQAMiAU MAP _M0S11.q�.��' 1��1•_i+70• /7023 * 11'N —. >e sPa r i it S st i.l v _ r rd LY' UM Me r NASA W.w a — S. � — —tN. _.—k. Vid ._ r.1 At Id Md.rdk .__.... r_ S S rte .—aP. a Matt Mid AS and NM riTJ.: i I + tr At 1 1 I I 1 I 1 I I • 1 I 1 1 I I ) t is _ • N 110 -- - - - • I \L ammear ;if �e i3<A NV1g N `a . 4.:ea y ns f.o TAIr Sti y}oQVY" go 0 ' A It' 00 t I, , hataa - - t _ "lis-syr / 1 ti n t11 t , , r i II _ I• tr — he, 1t oar I t m. f 4 . i; —T—-1 e_.4 II ,/ t j. •t _ !t C .r _ ,t s L=4 _ S r _ orb' _ 1 40, 1 .4 _ L 5 —$ 2, _ 4/ , , , , • s a is S — — s - - Ia - — s 7 I I Ik / 1 1 A t _ I 1 .�_/I r t` - 41 1 t , 4 1 4 _ 40 i>41IP I! \\\ 9 1• A AZ C 2 area YIVC a1 i Or w p t. 1-44 I r I (I %,I 1'1 I?tat_ En]. - m x �llY % 74041.11 I 1 44: a 9 BOULTER - CLOUDBREAK WELD COUNTY. COLORADO USE BV SPECIAL REVIEW POST -CONSTRUCTION DRAINAGE MAP Kimley>Horn ,t1 2C23 ♦ Nlf t --$04N AMO %SSOOATii AG '195 11'11 SI't 5 -. 5J1. '400 Own'. Cdo.one 50702 (S)3) 126 2102 CLOUOMGni %111 51.1. is-.., NQ to w • Kimley>>)Horn_ STANDARD FORM SF 1 RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION - PRE -CONSTRUCTION PROJECT NAME: PROJECT NUMBER: 196664000 Weld County - Cloudbreak - Michael Boulter South 5/3/2023 CALCULATED BY: JCH CHECKED BY: AJH TYPE D SOIL VEGETATED BUILDING FUTURE LAND PAVED GRAVEL USE: AREA AREA OPEN AREA SPACE ROOF COMMERCIAL AREA AREA 2 -YEAR COEFF. 0.83 0.30 0.01 0.74 0.69 5 -YEAR COEFF. 0.84 0.36 0.05 0.76 0.72 100 -YEAR COEFF. 0.89 0.65 0.49 0.85 0.83 IMPERVIOUS % 100% 40% 2% 90% 85% DESIGN BASIN Cc(2) Cc(5) Cc(100) Imp % VEGETATED BUILDING FUTURE PAVED GRAVEL OPEN SPACE ROOF COMMERCIAL TOTAL DESIGN AREA AREA AREA AREA AREA AREA POINT (AC) (AC) (AC) (AC) (AC) (AC) On -Site Basins PRE -DA -01 1 3.02 3.02 0.01 0.05 0.49 2.0% PRE -DA -02 2 3.23 3.23 0.01 0.05 0.49 2.0% PRE -DA -03 3 13.25 13.25 0.01 0.05 0.49 2.0% PRE -DA -04 4 0.41 15.18 15.59 0.02 0.06 0.50 3.0% PRE -DA -05 5 0.19 9.05 9.24 0.02 0.06 0.50 2.8% PRE -DA -06 6 0.15 2.86 3.01 0.02 0.07 0.50 3.9% PRE -DA -07 7 1.92 1.92 0.01 0.05 0.49 2.0% PRE -DA -08 8 0.29 4.54 4.82 0.03 0.07 0.50 4.3% PRE -DA -09 9 6.14 6.14 a 0.01 0.05 0.49 2.0% PRE -DA -10 10 0.06 7.78 7.84 0.01 0.05 0.49 2.3% PRE -DA -11 11 1.61 1.61 0.01 0.05 0.49 2.0% PRE -DA -12 12 0.06 2.01 2.07 0.02 0.06 0.50 3.1% PRE -DA -13 13 0.78 3.54 4.32 0.06 0.11 0.52 8.9% PRE -DA -14 14 0.04 3.17 3.21 0.01 0.06 0.49 2.5% PRE -DA -15 15 2.50 2.50 0.01 0.05 0.49 2.0% PRE -DA -16 16 0.02 5.09 5.10 0.01 0.05 0.49 2.1% PRE -DA -17 17 0.77 0.77 0.01 0.05 0.49 2.0% PRE -DA -18 18 0.01 3.51 3.51 0.01 0.05 0.49 2.1% PRE -DA -19 19 1.00 1.00 0.01 0.05 0.49 2.0% PRE -DA -20 20 0.15 4.56 4.71 0.02 0.06 0.50 3.2% BASIN 0.00 2.15 94.70 0.00 0.00 96.86 0.02 0.06 0.50 2.8% SUBTOTAL 0% 2% 98% 0% 0% 100% Kimley>>> Horn STANDARD FORM SF -2 TIME OF CONCENTRATION - PRE -CONSTRUCTION PRO. ECT NAME: Weld County - Cloudbreak - Michael Boulter South DATE: 5/3/2023 PROJECT NUMBER: CALCULATED CHECKED BY: BY: 196664000 JCH AJH FINAL SUB -BASIN INITIAL TRAVEL TIME Tc CHECK DATA (Ti) Tc (URBANIZED BASINS) TIME (T;) DESIGN AREA C5 (3) LENGTH (4) Ft SLOPE % (5) Ti Min. LENGTH SLOPE % (8) C, (9) Land (10) Surface Tt Min. COMP. (13) tc TOTAL TOTAL TOTAL Min. (17) Tc Min. C2 C5 C100 VEL fps (11) Ac (2) Ft. (7) LENGTH (14) SLOPE (15) IMP. (16) BASIN (1) (6) (12) On -Site Basins PRE -DA -01 3.021 0.05 498 1.1% 41.9 Tillage/Field 41.9 498 1.1% 2% 34.3 34.3 0.01 0.05 0.49 PRE -DA -02 3.233 0.05 500 0.6% 51.3 96 0.1% 5.0 Tillage/Field 0.1 12.9 64.2 596 0.5% 2% 40.8 40.8 0.01 0.05 0.49 PRE -DA -03 13.247 0.05 500 0.5% 54.8 1,067 0.2% 5.0 Tillage/Field 0.2 74.2 129.1 1567 0.3% 2% 76.2 76.2 0.01 0.05 0.49 PRE -DA -04 15.587 0.06 500 0.8% 46.7 1,124 0.0% 5.0 Tillage/Field 0.1 362.7 409.4 1624 0.2% 3% 83.9 83.9 0.02 0.06 0.50 PRE -DA -05 9.241 0.06 500 1.6% 36.6 240 0.4% 5.0 Tillage/Field 0.3 12.2 48.7 740 1.2% 3% 37.4 37.4 0.02 0.06 0.50 PRE -DA -06 3.013 0.07 466 1.5% 36.1 Tillage/Field 36.1 466 1.5% 4% 32.1 32.1 0.02 0.07 0.50 PRE -DA -07 1.918 0.05 466 1.0% 41.5 Tillae/Field 41.5 466 1.0% 2% 34.0 34.0 0.01 0.05 0.49 PRE -DA -08 4.823 0.07 441 0.7% 45.1 Tillage/Field 45.1 441 0.7% 4% 34.5 34.5 0.03 0.07 0.50 PRE -DA -09 6.137 0.05 500 0.5% 52.7 204 0.0% 5.0 Tillage/Field 0.1 34.3 87.0 704 0.4% 2% 45.7 45.7 0.01 0.05 0.49 PRE -DA -10 7.840 0.05 500 0.5% 52.8 247 0.2% 5.0 Tillage/Field 0.2 17.8 70.5 747 0.4% 2% 45.9 45.9 0.01 0.05 0.49 PRE -DA -11 1.605 0.05 433 0.6% 47.5 Tillage/Field 47.5 433 0.6% 2% 35.7 35.7 0.01 0.05 0.49 PRE -DA -12 2.070 0.06 211 0.3% 40.6 Tillage/Field 40.6 211 0.3% 3% 32.1 32.1 0.02 0.06 0.50 PRE -DA -13 4.321 0.11 500 0.6% 49.3 217 0.2% 5.0 Tillage/Field 0.2 15.7 65.0 717 0.5% 9% 41.7 41.7 0.06 0.11 0.52 PRE -DA -14 3.214 0.06 500 1.2% 40.4 114 0.5% 5.0 Tillae/Field 0.3 5.5 46.0 614 1.1% 3% 36.2 36.2 0.01 0.06 0.49 PRE -DA -15 2.496 0.05 293 0.2% 61.9 Tillage/Field 61.9 293 0.2% 2% 39.2 39.2 0.01 0.05 0.49 PRE -DA -16 5.101 0.05 500 1.2% 40.6 166 0.8% 5.0 Tillage/Field 0.5 6.1 46.8 666 1.1% 2% 37.1 37.1 0.01 0.05 0.49 PRE -DA -17 0.774 0.05 261 1.2% 28.9 Tillage/Field 28.9 261 1.2% 2% 29.9 28.9 0.01 0.05 0.49 PRE -DA -18 3.512 0.05 500 1.0% 43.1 361 0.3% 5.0 Tillage/Field 0.3 22.4 65.5 861 0.7% 2% 44.1 44.1 0.01 0.05 0.49 PRE -DA -19 0.996 0.05 321 0.9% 35.6 Tillage/Field 35.6 321 0.9% 2% 31.7 31.7 0.01 0.05 0.49 PRE -DA -20 4.708 0.06 484 0.7% 46.9 Tillage/Field 46.9 484 0.7% 3% 35.6 35.6 0.02 0.06 0.50 1 4 0.39:11. C_ �k t: x -33 _I _ t. (26 M _ �� 7� O : 6y�f 1: 'fy Y},y { lj P A STANDARD FORM SF -3 Kimley>>> Horn STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT - PRE -CONSTRUCTION PRO.IF-F;CT NAME: Weld County - Cloudbreak - Michael Boulter South DATE' 5/3/2023 PRO.IF-F;CT NUMBER: 196664000 P1 (1 -Hour Rainfall) = 2.71 CALCULATED CHECKED BY: BY: JCH ASH REMARKS TRAVEL TIME DIRECT RUNOFF TOTAL RUNOFF STREET PIPE (u!ui) aj IGN VV(cfs I GT] rt) 4 v� ~ a )V` o�.4t •- �� 1 )E a o 0 OO � w ozcA .e� Il cl) A A P74 CID (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) On -Site Basins 1 PRE -DA -01 3.02 0.49 34.30 1.49 3.92 5.84 i 2 PRE -DA -02 3.23 0.49 40.76 1.59 3.53 5.61 3 PRE -DA -03 13.25 0.49 76.20 6.52 2.33 15.16 4 PRE -DA -04 15.59 0.50 83.90 7.74 2.17 16.82 5 PRE -DA -05 9.24 0.50 37.42 4.58 3.72 17.03 6 PRE -DA -06 3.01 0.50 32.09 1.51 4.09 6.16 7 PRE -DA -07 1.92 0.49 34.02 0.94 3.94 3.72 8 PRE -DA -08 4.82 0.50 34.55 2.42 3.91 9.45 9 PRE -DA -09 6.14 0.49 45.70 3.02 3.28 9.90 10 PRE -DA -10 7.84 0.49 45.95 3.87 3.27 12.63 11 PRE -DA -11 1.61 0.49 35.72 0.79 3.83 3.02 12 PRE -DA -12 2.07 0.50 32.09 1.03 4.09 4.20 13 PRE -DA -13 4.32 0.52 41.73 2.25 3.47 7.81 14 PRE -DA -14 3.21 0.49 36.24 1.59 3.79 6.03 15 PRE -DA -15 2.50 0.49 39.24 1.23 3.61 4.44 16 PRE -DA -16 5.10 0.49 37.07 2.51 3.74 9.40 17 PRE -DA -17 0.77 0.49 28.92 0.38 4.34 1.66 18 PRE -DA -18 3.51 0.49 44.14 1.73 3.35 5.80 19 PRE -DA -19 1.00 0.49 31.71 0.49 4.11 2.02 20 PRE -DA -20 4.71 0.50 35.58 2.34 3.84 8.98 Total 96.86 155.67 Kimley>>) Horn STANDARD FORM SF -1 RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION - POST -CONSTRUCTION PROJECT NAME: Weld County - Cloudbreak - Michael Boulter South 5/3/2023 PROJECT NUMBER: 196664000 CALCULATED BY: LDS CHECKED BY: AJH TYPED SOIL VEGETATED BUILDING FUTURE PAVED GRAVEL OPEN SPACE ROOF COMMERCIAL LAND USE: AREA AREA AREA AREA AREA 2 -YEAR COEFF. 0.83 0.30 0.01 0.74 0.69 5 -YEAR COEFF. 0.84 0.36 0.05 0.76 0.72 100 -YEAR COEFF. 0.89 0.65 0.49 0.85 0.83 IMPERVIOUS % 100% 40% 2% 90% 85% DESIGN BASIN VEGETATED BUILDING FUTURE Cc(2) Cc(5) Cc(100) Imp % PAVED GRAVEL OPEN SPACE ROOF COMMERCIAL TOTAL DESIGN AREA AREA AREA AREA AREA AREA POINT (AC) (AC) (AC) (AC) (AC) (AC) On -Site Basins POST -DA -01 1 0.14 2.88 3.02 0.02 0.07 0.50 3.8% POST -DA -02 2 3.23 3.23 0.01 0.05 0.49 2.0% POST -DA -03 3 0.06 0.56 12.62 13.25 0.03 0.07 0.50 4.1% POST -DA -04 4 0.06 0.24 15.28 15.59 0.02 0.06 0.50 3.0% POST -DA -05 5 0.21 9.03 9.24 0.02 0.06 0.50 2.9% POST -DA -06 6 0.15 2.86 3.01 0.02 0.07 0.50 3.9% POST -DA -07 7 1.92 1.92 0.01 0.05 0.49 2.0% POST -DA -08 8 0.23 4.60 4.82 0.02 0.07 0.50 3.8% POST -DA -09 9 6.14 6.14 0.01 0.05 0.49 2.0% POST -DA -10 10 0.03 0.18 7.62 7.84 0.02 0.06 0.50 3.3% POST -DA -11 11 1.61 1.61 0.01 0.05 0.49 2.0% POST -DA -12 12 0.06 2.01 2.07 0.02 0.06 0.50 3.1% POST -DA -13 13 0.03 0.23 4.06 4.32 0.03 0.07 0.50 4.7% POST -DA -14 14 0.03 0.08 3.11 3.21 0.03 0.07 0.50 3.9% POST -DA -15 15 2.50 2.50 0.01 0.05 0.49 2.0% POST -DA -16 16 0.02 5.09 5.10 0.01 0.05 0.49 2.1% POST -DA -17 17 0.77 0.77 0.01 0.05 0.49 2.0% POST -DA -18 18 0.01 3.51 3.51 0.01 0.05 0.49 2.1% POST -DA -19 19 1.00 1.00 0.01 0.05 0.49 2.0% POST -DA -20 20 0.24 4.47 4.71 0.02 0.07 0.50 3.9% BASIN SUBTOTAL 0.22 2.35 94.29 0.00 0.00 96.86 0.02 0.06 0.50 3.1% 0% 2% 97% 0% 0% 100% Kimley>>> Horn STANDARD FORM SF -2 TIME OF CONCENTRATION - POST -CONSTRUCTION PROJECT NAME: Weld County - Cloudbreak - Michael Boulter South DATE: 5/3/2023 PROJECT NUMBER: 196664000 CALCULATED BY: LDS CHECKED BY: AJH INITIAL TRAVEL TIME Te CHECK FINAL Tc t. SUB -BASIN DATA (Ti) (URBANIZED BASINS) TIME (Ti) DESIGN BASIN AREA Ac (2) CS (3) SLOPE Ti Min. (6) SLOPE % (8) C, (9) Land Surface Min. (12) Tt COMP. (13) to TOTAL TOTAL TOTAL Min. (17) Tc Min. C2 C_5 i C100 LENGTH LENGTH VEL Ft (4) % (5) Ft. (7) (10) fps (11) SLOPE (15) IMP. LENGTH (1) (14) (16) On -Site Basins POST -DA -01 3.021 0.07 498 1.1% 41.4 Tillage/Field 41.4 498 1.1% 4% 33.8 33.8 0.02 0.07 0.50 POST -DA -02 3.233 0.05 500 0.6% 51.3 96 0.1% 5.0 Tillage/Field 0.1 12.9 64.2 596 0.5% 2% 40.8 40.8 0.01 0.05 0.49 POST -DA -03 13.247 0.07 500 0.5% 54.0 1,067 0.2% 5.0 Tillage/Field 0.2 74.2 128.2 1567 0.3% 4% 74.3 74.3 0.03 0.07 0.50 POST -DA -04 15.587 0.06 500 0.8% 46.7 1,124 0.0% 5.0 Tillage/Field 0.1 362.7 409.4 1624 0.2% 3% 83.9 83.9 0.02 0.06 0.50 POST -DA -05 9.241 0.06 500 1.6% 36.5 240 0.4% 5.0 Tillage/Field 0.3 12.2 48.7 740 1.2% 3% 37.4 37.4 0.02 0.06 0.50 POST -DA -06 3.013 0.07 466 1.5% 36.1 Tillage/Field 36.1 466 1.5% 4% 32.1 32.1 0.02 0.07 0.50 POST -DA -07 1.918 0.05 466 1.0% 41.5 Tillage/Field 41.5 466 1.0% 2% 34.0 34.0 0.01 0.05 0.49 POST -DA -08 4.823 0.07 441 0.7% 45.2 Tillage/Field 45.2 441 0.7% 4% 34.7 34.7 0.02 0.07 0.50 POST -DA -09 6.137 0.05 500 0.5% 52.7 204 0.0% 5.0 Tillage/Field 0.1 34.3 87.0 704 0.4% 2% 45.7 45.7 0.01 0.05 0.49 POST -DA -10 7.840 0.06 500 0.5% 52.4 247 0.2% 5.0 Tillage/Field 0.2 17.8 70.1 747 0.4% 3% 45.5 45.5 0.02 0.06 0.50 POST -DA -11 1.605 0.05 433 0.6% 47.5 Tillage/Field 47.5 433 0.6% 2% 35.7 35.7 0.01 0.05 0.49 POST -DA -12 2.070 0.06 211 0.3% 40.6 Tillage/Field 40.6 211 0.3% 3% 32.1 32.1 0.02 0.06 0.50 POST -DA -13 4.321 0.07 500 0.6% 51.0 217 0.2% 5.0 Tillage/Field 0.2 15.7 66.7 717 0.5% 5% 43.5 43.5 0.03 0.07 0.50 POST -DA -14 3.214 0.07 500 1.2% 40.0 114 0.5% 5.0 Tillage/Field 0.3 5.5 45.6 614 1.1% 4% 35.8 35.8 0.03 0.07 0.50 POST -DA -15 2.496 0.05 293 0.2% 61.9 Tillage/Field 61.9 293 0.2% 2% 39.2 39.2 0.01 0.05 0.49 POST -DA -16 5.101 0.05 500 1.2% 40.6 166 0.8% 5.0 Tillage/Field 0.5 6.1 46.8 666 1.1% 2% 37.1 37.1 0.01 0.05 0.49 POST -DA -17 0.774 0.05 261 1.2% 28.9 Tillage/Field 28.9 261 1.2% 2% 29.9 28.9 0.01 0.05 0.49 POST -DA -18 3.512 0.05 500 1.0% 43.1 361 0.3% 5.0 Tillage/Field 0.3 22.4 65.5 861 0.7% 2% 44.1 44.1 0.01 0.05 0.49 POST -DA -19 0.996 0.05 321 0.9% 35.6 Tillage/Field 35.6 321 0.9% 2% 31.7 31.7 0.01 0.05 0.49 POST -DA -20 4.708 0.07 484 0.7% 46.7 Tillage/Field 46.7 484 0.7% 4% 35.3 35.3 0.02 0.07 0.50 fat — C Li t r s F. _0..3950.1 so 0_.33 X "mil s1F 601,; 60041+ 9)Ag STANDARD FORM SF -3 Kimle >>> Horn STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT - POST -CONSTRUCTION PROJECT NAME: Weld County - Cloudbreak - Michael Boulter South DA'iE: 5/3/2023 PROJECT NUMBER: 196664000 P1 (1 -Hour Rainfall) = 2.71 CALCULATED BY: LDS CHECKED BY: AJH DIRECT RUNOFF TOTAL RUNOFF STREET TRAVEL TIME REMARKS PIPE tc (min) C*A(ac) PO tAgmaN o 411 p.�"m51 4L•1 <C 4m c,611v tc(ma: a o ♦, r-, . � o� oW o� )` �� om co pa a� 7� w w o� CA �W V) c� ....- a E• W� W� .� `- �, D-4 ��, Gov .5 W VD al g (1) I (2) I (3) I (4) I (5) I (6) I (7) I (8) I (9) 1(10)1(11) 1(12)1 (13) 1(14)1(15)1(16) (17) I (18) I (19) 1(20)1(21) (22) On -Site Basins i 1 POST -DA -01 I 3.02 0.50 33.76 1.51 3.96 5.98 2 POST -DA -02 3.23 0.49 40.76 1.59 3.53 5.61 3 POST -DA -03 13.25 0.50 74.30 6.63 2.37 15.70 4 POST -DA -04 15.59 0.50 83.92 7.73 2.17 16.81 5 POST -DA -05 9.24 0.50 37.39 4.58 3.72 17.05 6 POST -DA -06 3.01 0.50 32.09 1.51 4.09 6.16 7 POST -DA -07 1.92 0.49 34.02 0.94 3.94 3.72 8 POST -DA -08 4.82 0.50 34.69 2.41 3.90 9.39 9 POST -DA -09 6.14 0.49 45.70 3.02 3.28 9.90 10 POST -DA -10 7.84 0.50 45.48 3.90 3.29 12.82 11 POST -DA -11 1.61 0.49 35.72 0.79 3.83 3.02 12 POST -DA -12 2.07 0.50 32.09 1.03 4.09 4.20 13 POST -DA -13 4.32 0.50 43.47 2.18 3.38 7.36 14 POST -DA -14 3.21 0.50 35.80 1.61 3.82 6.14 15 POST -DA -15 2.50 0.49 39.24 1.23 3.61 4.44 16 POST -DA -16 5.10 0.49 37.07 2.51 3.74 9.40 17 POST -DA -17 0.77 0.49 28.92 0.38 4.34 1.66 18 POST -DA -18 3.51 0.49 44.14 1.73 3.35 5.80 19 POST -DA -19 1.00 0.49 31.71 0.49 4.11 2.02 20 POST -DA -20 4.71 0.50 35.34 2.35 3.85 9.07 Total 96.86 156.25 Exhibit 7 — Hydrologic Response of Solar Farms Hydrologic Response of Solar Farms Lauren M. Cook, S.M.ASCE1; and Richard H. McCuen, M.ASCE2 Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. Abstract: Because of the benefits of solar energy, the number of solar farms is increasing; however, their hydrologic impacts have not been studied. The goal of this study was to determine the hydrologic effects of solar farms and examine whether or not storm -water management is needed to control runoff volumes and rates. A model of a solar farm was used to simulate runoff for two conditions: the pre- and postpaneled conditions. Using sensitivity analyses, modeling showed that the solar panels themselves did not have a significant effect on the runoff volumes, peaks, or times to peak. However, if the ground cover under the panels is gravel or bare ground, owing to design decisions or lack of maintenance, the peak discharge may increase significantly with storm -water management needed. In addition, the kinetic energy of the flow that drains from the panels was found to be greater than that of the rainfall, which could cause erosion at the base of the panels. Thus, it is recommended that the grass beneath the panels be well maintained or that a buffer strip be placed after the most downgradient row of panels. This study, along with design recommendations, can be used as a guide for the future design of solar farms. DOE 10.1061/(ASCE) HE.1943-5584.0000530. © 2013 American Society of Civil Engineers. CE Database subject headings: Hydrology; Land use; Solar power; Floods; Surface water; Runoff; Stormwater management. Author keywords: Hydrology; Land use change; Solar energy; Flooding; Surface water runoff; Storm -water management. Introduction Storm -water management practices are generally implemented to reverse the effects of land -cover changes that cause increases in volumes and rates of runoff. This is a concern posed for new types of land -cover change such as the solar farm. Solar energy is a re- newable energy source that is expected to increase in importance in the near future. Because solar farms require considerable land, it is necessary to understand the design of solar farms and their potential effect on erosion rates and storm runoff, especially the impact on offsite properties and receiving streams. These farms can vary in size from 8 ha (20 acres) in residential areas to 250 ha (600 acres) in areas where land is abundant. The solar panels are impervious to rain water; however, they are mounted on metal rods and placed over pervious land. In some cases, the area below the panel is paved or covered with gravel. Service roads are generally located between rows of panels. Altl- hough some panels are stationary, others are designed to move so that the angle of the panel varies with the angle of the sun. The angle can range, depending on the latitude, from 22° during the summer months to 74° during the winter months. In addition, the angle and direction can also change throughout the day. The issue posed is whether or not these rows of impervious panels will change the runoff characteristics of the site, specifically increase runoff volumes or peak discharge rates. If the increases are hydro- logically significant, storm -water management facilities may be needed. Additionally, it is possible that the velocity of water 1Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Maryland, College Park, MD 20742-3021. 2The Ben Dyer Professor, Dept. of Civil and Environmental Engineer- ing, Univ. of Maryland, College Park, MD 20742-3021 (corresponding author). E-mail: rhmccuen@eng.umd.edu Note. This manuscript was submitted on August 12, 2010; approved on October 20, 2011; published online on October 24, 2011. Discussion period open until October 1, 2013; separate discussions must be submitted for individual papers. This paper is part of the Journal of Hydrologic Engi- neering, Vol. 18, No. 5, May 1, 2013. © ASCE, ISSN 1084-069912013/5- 536-541/$25.00. draining from the edge of the panels is sufficient to cause erosion of the soil below the panels, especially where the maintenance roadways are bare ground. The outcome of this study provides guidance for assessing the hydrologic effects of solar farms, which is important to those who plan, design, and install arrays of solar panels. Those who design solar farms may need to provide for storm -water management. This study investigated the hydrologic effects of solar farms, assessed whether or not storm -water management might be needed, and if the velocity of the runoff from the panels could be sufficient to cause erosion of the soil below the panels. Model Development Solar farms are generally designed to maximize the amount of en- ergy produced per unit of land area, while still allowing space for maintenance. The hydrologic response of solar farms is not usually considered in design. Typically, the panels will be arrayed in long rows with separations between the rows to allow for maintenance vehicles. To model a typical layout, a unit width of one panel was assumed, with the length of the downgradient strip depending on the size of the farm. For example, a solar farm with 30 rows of 200 panels each could be modeled as a strip of 30 panels with space between the panels for maintenance vehicles. Rainwater that drains from the upper panel onto the ground will flow over the land under the 29 panels on the downgradient strip. Depending on the land cover, infiltration losses would be expected as the runoff flows to the bottom of the slope. To determine the effects that the solar panels have on runoff characteristics, a model of a solar farm was developed. Runoff in the form of sheet flow without the addition of the solar panels served as the prepaneled condition. The paneled condition assumed a downgradient series of cells with one solar panel per ground cell. Each cell was separated into three sections: wet, dry, and spacer. The dry section is that portion directly underneath the solar panel, unexposed directly to the rainfall. As the angle of the panel from the horizontal increases, more of the rain will fall directly onto 536 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. the ground; this section of the cell is referred to as the wet section. The spacer section is the area between the rows of panels used by maintenance vehicles. Fig. 1 is an image of two solar panels and the spacer section allotted for maintenance vehicles. Fig. 2 is a sche- matic of the wet, dry, and spacer sections with their respective di- mensions. In Fig. 1, tracks from the vehicles are visible on what is modeled within as the spacer section. When the solar panel is hori- zontal, then the length longitudinal to the direction that runoff will occur is the length of the dry and wet sections combined. Runoff from a dry section drains onto the downgradient spacer section. Runoff from the spacer section flows to the wet section of the next downgradient cell. Water that drains from a solar panel falls directly onto the spacer section of that cell. The length of the spacer section is constant. During a storm event, the loss rate was assumed constant for the 24-h storm be- cause a wet antecedent condition was assumed. The lengths of the wet and dry sections changed depending on the angle of the solar panel. The total length of the wet and dry sections was set Fig. 1. Maintenance or "spacer" section between two rows of solar panels (photo by John E. Showler, reprinted with permission) Ld Direction of Flow Wet section Dry section Spacer section 5 m 3.5 m Fig. 2. Wet, dry, and spacer sections of a single cell with lengths Lw, Ls, and Ld with the solar panel covering the dry section equal to the length of one horizontal solar panel, which was as- sumed to be 3.5 m. When a solar panel is horizontal, the dry section length would equal 3.5 m and the wet section length would be zero. In the paneled condition, the dry section does not receive direct rainfall because the rain first falls onto the solar panel then drains onto the spacer section. However, the dry section does infiltrate some of the runoff that comes from the upgradient wet section. The wet section was modeled similar to the spacer section with rain falling directly onto the section and assuming a constant loss rate. For the presolar panel condition, the spacer and wet sections are modeled the same as in the paneled condition; however, the cell does not include a dry section. In the prepaneled condition, rain falls directly onto the entire cell. When modeling the prepaneled condition, all cells receive rainfall at the same rate and are subject to losses. All other conditions were assumed to remain the same such that the prepaneled and paneled conditions can be compared. Rainfall was modeled after an natural resources conservation service (NRCS) Type II Storm (McCuen 2005) because it is an ac- curate representation of actual storms of varying characteristics that are imbedded in intensity -duration -frequency (IDF) curves. For each duration of interest, a dimensionless hyetograph was devel- oped using a time increment of 12 s over the duration of the storm (see Fig. 3). The depth of rainfall that corresponds to each storm magnitude was then multiplied by the dimensionless hyetograph. For a 2-h storm duration, depths of 40.6, 76.2, and 101.6 mm were used for the 2-, 25-, and 100 -year events. The 2- and 6-h duration hyetographs were developed using the center portion of the 24-h storm, with the rainfall depths established with the Baltimore IDF curve. The corresponding depths for a 6-h duration were 53.3, 106.7, and 132.1 mm, respectively. These magnitudes were chosen to give a range of storm conditions. During each time increment, the depth of rain is multiplied by the cell area to determine the volume of rain added to each section of each cell. This volume becomes the storage in each cell. Depend- ing on the soil group, a constant volume of losses was subtracted from the storage. The runoff velocity from a solar panel was calcu- lated using Manning's equation, with the hydraulic radius for sheet flow assumed to equal the depth of the storage on the panel (Bedient and Huber 2002). Similar assumptions were made to com- pute the velocities in each section of the surface sections. 20 40 60 Time (min) 80 100 120 Fig. 3. Dimensionless hyetograph of 2-h Type II storm JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 537 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. Runoff from one section to the next and then to the next downgradient cell was routed using the continuity of mass. The routing coefficient depended on the depth of flow in storage and the velocity of runoff. Flow was routed from the wet section to the dry section to the spacer section, with flow from the spacer section draining to the wet section of the next cell. Flow from the most downgradient cell was assumed to be the outflow. Discharge rates and volumes from the most downgradient cell were used for com- parisons between the prepaneled and paneled conditions. Alternative Model Scenarios To assess the effects of the different variables, a section of 30 cells, each with a solar panel, was assumed for the base model. Each cell was separated individually into wet, dry, and spacer sections. The area had a total ground length of 225 m with a ground slope of 1% and width of 5 m, which was the width of an average solar panel. The roughness coefficient (Engman 1986) for the silicon solar panel was assumed to be that of glass, 0.01. Roughness coefficients of 0.15 for grass and 0.02 for bare ground were also assumed. Loss rates of 0.5715 cm/h (0.225 in./h) and 0.254 cm/h (0.1 in./h) for B and C soils, respectively, were assumed. The prepaneled condition using the 2-h, 25 -year rainfall was assumed for the base condition, with each cell assumed to have a good grass cover condition. All other analyses were made assum- ing a paneled condition. For most scenarios, the runoff volumes and peak discharge rates from the paneled model were not significantly greater than those for the prepaneled condition. Over a total length of 225 m with 30 solar panels, the runoff increased by 0.26 m3, which was a difference of only 0.35%. The slight increase in runoff volume reflects the slightly higher velocities for the paneled con- dition. The peak discharge increased by 0.0013 m3, a change of only 0.31%. The time to peak was delayed by one time increment, i.e., 12 s. Inclusion of the panels did not have a significant hydro- logic impact. Storm Magnitude The effect of storm magnitude was investigated by changing the magnitude from a 25 -year storm to a 2 -year storm. For the 2 -year storm, the rainfall and runoff volumes decreased by approximately 50%. However, the runoff from the paneled watershed condition increased compared to the prepaneled condition by approximately the same volume as for the 25 -year analysis, 0.26 m3. This increase represents only a 0.78% increase in volume. The peak discharge and the time to peak did not change significantly. These results re- flect runoff from a good grass cover condition and indicated that the general conclusion of very minimal impacts was the same for dif- ferent storm magnitudes. Ground Slope The effect of the downgradient ground slope of the solar farm was also examined. The angle of the solar panels would influence the velocity of flows from the panels. As the ground slope was in- creased, the velocity of flow over the ground surface would be closer to that on the panels. This could cause an overall increase in discharge rates. The ground slope was changed from 1 to 5%, with all other conditions remaining the same as the base conditions. With the steeper incline, the volume of losses decreased from that for the 1% slope, which is to be expected because the faster velocity of the runoff would provide less opportunity for infiltra- tion. However, between the prepaneled and paneled conditions, the increase in runoff volume was less than 1%. The peak discharge and the time to peak did not change. Therefore, the greater ground slope did not significantly influence the response of the solar farm. Soil Type The effect of soil type on the runoff was also examined. The soil group was changed from B soil to C soil by varying the loss rate. As expected, owing to the higher loss rate for the C soil, the depths of runoff increased by approximately 7.5% with the C soil when com- pared with the volume for B soils. However, the runoff volume for the C soil condition only increased by 0.17% from the prepaneled condition to the paneled condition. In comparison with the B soil, a difference of 0.35% in volume resulted between the two conditions. Therefore, the soil group influenced the actual volumes and rates, but not the relative effect of the paneled condition when compared to the prepaneled condition. Panel Angle Because runoff velocities increase with slope, the effect of the angle of the solar panel on the hydrologic response was examined. Analy- ses were made for angles of 30° and 70° to test an average range from winter to summer. The hydrologic response for these angles was compared to that of the base condition angle of 45°. The other site conditions remained the same. The analyses showed that the angle of the panel had only a slight effect on runoff volumes and discharge rates. The lower angle of 30° was associated with an in- creased runoff volume, whereas the runoff volume decreased for the steeper angle of 70° when compared with the base condition of 45°. However, the differences (-0.5%) were very slight. Never- theless, these results indicate that, when the solar panel was closer to horizontal, i.e., at a lower angle, a larger difference in runoff volume occurred between the prepaneled and paneled conditions. These differences in the response result are from differences in loss rates. The peak discharge was also lower at the lower angle. At an angle of 30°, the peak discharge was slightly lower than at the higher angle of 70°. For the 2-h storm duration, the time to peak of the 30° angle was 2 min delayed from the time to peak of when the panel was positioned at a 70° angle, which reflects the longer travel times across the solar panels. Storm Duration To assess the effect of storm duration, analyses were made for 6-h storms, testing magnitudes for 2-, 25-, and 100 -year return periods, with the results compared with those for the 2-h rainfall events. The longer storm duration was tested to determine whether a longer du- ration storm would produce a different ratio of increase in runoff between the prepaneled and paneled conditions. When compared to runoff volumes from the 2-h storm, those for the 6-h storm were 34% greater in both the paneled and prepaneled cases. However, when comparing the prepaneled to the paneled condition, the in- crease in the runoff volume with the 6-h storm was less than 1% regardless of the return period. The peak discharge and the time -to -peak did not differ significantly between the two condi- tions. The trends in the hydrologic response of the solar farm did not vary with storm duration. Ground Cover The ground cover under the panels was assumed to be a native grass that received little maintenance. For some solar farms, the area be- neath the panel is covered in gravel or partially paved because the panels prevent the grass from receiving sunlight. Depending on the 538 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. volume of traffic, the spacer cell could be grass, patches of grass, or bare ground. Thus, it was necessary to determine whether or not these alternative ground -cover conditions would affect the runoff characteristics. This was accomplished by changing the Manning's n for the ground beneath the panels. The value of n under the pan- els, i.e., the dry section, was set to 0.015 for gravel, with the value for the spacer or maintenance section set to 0.02, i.e., bare ground. These can be compared to the base condition of a native grass (n = 0.15). A good cover should promote losses and delay the runoff. For the smoother surfaces, the velocity of the runoff increased and the losses decreased, which resulted in increasing runoff vol- umes. This occurred both when the ground cover under the panels was changed to gravel and when the cover in the spacer section was changed to bare ground. Owing to the higher velocities of the flow, runoff rates from the cells increased significantly such that it was necessary to reduce the computational time increment. Fig. 4(a) shows the hydrograph from a 30 -panel area with a time incre- ment of 12 s. With a time increment of 12 s, the water in each cell is discharged at the end of every time increment, which results in no attenuation of the flow; thus, the undulations shown in Fig. 4(a) result. The time increment was reduced to 3 s for the 2-h storm, which resulted in watershed smoothing and a rational hydrograph shape [Fig. 4(b)] . The results showed that the storm runoff 0.1 0.09 0.08 0.07 coE 0.06 0 0.05 co 0 0.04 0.03 (a) 0.02 0.01 0 0.07 0.06 0.05 U) 0.04 0.03 0.02 0.01 20 40 60 80 100 120 140 160 180 Time (min) 0 _ 0 (b) I Paneled Pre -paneled 4 - alb NC IS 20 40 60 80 100 120 140 160 Time (min) 180 200 Fig. 4. Hydrograph with time increment of (a) 12 s; (b) 3 s with Manning's n for bare ground increased by 7% from the grass -covered scenario to the scenario with gravel under the panel. The peak discharge increased by 73% for the gravel ground cover when compared with the grass cover without the panels. The time to peak was 10 min less with the gravel than with the grass, which reflects the effect of differ- ences in surface roughness and the resulting velocities. If maintenance vehicles used the spacer section regularly and the grass cover was not adequately maintained, the soil in the spacer section would be compacted and potentially the runoff volumes and rates would increase. Grass that is not maintained has the potential to become patchy and turn to bare ground. The grass under the panel may not get enough sunlight and die. Fig. 1 shows the result of the maintenance trucks frequently driving in the spacer section, which diminished the grass cover. The effect of the lack of solar farm maintenance on runoff char- acteristics was modeled by changing the Manning's n to a value of 0.02 for bare ground. In this scenario, the roughness coefficient for the ground under the panels, i.e., the dry section, as well as in the spacer cell was changed from grass covered to bare ground (n = 0.02).The effects were nearly identical to that of the gravel. The runoff volume increased by 7% from the grass -covered to the bare -ground condition. The peak discharge increased by 72% when compared with the grass -covered condition. The runoff for the bare - ground condition also resulted in an earlier time to peak by approx- imately 10 min. Two other conditions were also modeled, showing similar results. In the first scenario, gravel was placed directly under the panel, and healthy grass was placed in the spacer section, which mimics a possible design decision. Under these conditions, the peak discharge increased by 42%, and the volume of runoff increased by 4%, which suggests that storm -water management would be necessary if gravel is placed anywhere. Fig. 5 shows two solar panels from a solar farm in New Jersey. The bare ground between the panels can cause increased runoff rates and reductions in time of concentration, both of which could necessitate storm -water management. The final condition modeled involved the assumption of healthy grass beneath the panels and bare ground in the spacer section, which would simulate the con- dition of unmaintained grass resulting from vehicles that drive over the spacer section. Because the spacer section is 53% of the cell, the change in land cover to bare ground would reduce losses and de- crease runoff travel times, which would cause runoff to amass as it Fig. 5. Site showing the initiation of bare ground below the panels, which increases the potential for erosion (photo by John Showler, reprinted with permission) JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 539 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. moves downgradient. With the spacer section as bare ground, the peak discharge increased by 100%, which reflected the increases in volume and decrease in timing. These results illustrate the need for maintenance of the grass below and between the panels. Design Suggestions With well -maintained grass underneath the panels, the solar panels themselves do not have much effect on total volumes of the runoff or peak discharge rates. Although the panels are impervious, the rainwater that drains from the panels appears as runoff over the downgradient cells. Some of the runoff infiltrates. If the grass cover of a solar farm is not maintained, it can deteriorate either because of a lack of sunlight or maintenance vehicle traffic. In this case, the runoff characteristics can change significantly with both runoff rates and volumes increasing by significant amounts. In addition, if gravel or pavement is placed underneath the panels, this can also contribute to a significant increase in the hydrologic response. If bare ground is foreseen to be a problem or gravel is to be placed under the panels to prevent erosion, it is necessary to counteract the excess runoff using some form of storm -water man- agement. A simple practice that can be implemented is a buffer strip (Dabney et al. 2006) at the downgradient end of the solar farm. The buffer strip length must be sufficient to return the runoff character- istics with the panels to those of runoff experienced before the gravel and panels were installed. Alternatively, a detention basin can be installed. A buffer strip was modeled along with the panels. For approxi- mately every 200 m of panels, or 29 cells, the buffer must be 5 cells long (or 35 m) to reduce the runoff volume to that which occurred before the panels were added. Even if a gravel base is not placed under the panels, the inclusion of a buffer strip may be a good prac- tice when grass maintenance is not a top funding priority. Fig. 6 shows the peak discharge from the graveled surface versus the length of the buffer needed to keep the discharge to prepaneled peak rate. Water draining from a solar panel can increase the potential for erosion of the spacer section. If the spacer section is bare ground, the high kinetic energy of water draining from the panel can cause soil detachment and transport (Garde and Raju 1977; Beuselinck et al. 2002). The amount and risk of erosion was modeled using the velocity of water coming off a solar panel compared with the velocity and intensity of the rainwater. The velocity of panel 0.07 0.06 0.05 M 0.04 0 11 0.03 o_ 0.02 0.01 5 10 15 20 25 Length of buffer (m) Pre -paneled peak Q Peak Q vs. buffer length - 30 35 40 Fig. 6. Peak discharge over gravel compared with buffer length runoff was calculated using Manning's equation, and the velocity of falling rainwater was calculated using the following: Vt = 120 d).35 (1) where d,. = diameter of a raindrop, assumed to be 1 mm. The re- lationship between kinetic energy and rainfall intensity is Ke = 916 + 3301og10 i (2) where i = rainfall intensity (in./h) and Ke = kinetic energy (ft -tons per ac -in. of rain) of rain falling onto the wet section and the panel, as well as the water flowing off of the end of the panel (Wischmeier and Smith 1978). The kinetic energy (Salles et al. 2002) of the rain- fall was greater than that coming off the panel, but the area under the panel (i.e., the product of the length, width, and cosine of the panel angle) is greater than the area under the edge of the panel where the water drains from the panel onto the ground. Thus, dividing the kinetic energy by the respective areas gives a more accurate representation of the kinetic energy experienced by the soil. The energy of the water draining from the panel onto the ground can be nearly 10 times greater than the rain itself falling onto the ground area. If the solar panel runoff falls onto an un- sealed soil, considerable detachment can result (Motha et al. 2004). Thus, because of the increased kinetic energy, it is pos- sible that the soil is much more prone to erosion with the panels than without. Where panels are installed, methods of erosion control should be included in the design. Conclusions Solar farms are the energy generators of the future; thus, it is im- portant to determine the environmental and hydrologic effects of these farms, both existing and proposed. A model was created to simulate storm -water runoff over a land surface without panels and then with solar panels added. Various sensitivity analyses were conducted including changing the storm duration and volume, soil type, ground slope, panel angle, and ground cover to determine the effect that each of these factors would have on the volumes and peak discharge rates of the runoff. The addition of solar panels over a grassy field does not have much of an effect on the volume of runoff, the peak discharge, nor the time to peak. With each analysis, the runoff volume increased slightly but not enough to require storm -water management facili- ties. However, when the land -cover type was changed under the panels, the hydrologic response changed significantly. When gravel or pavement was placed under the panels, with the spacer section left as patchy grass or bare ground, the volume of the runoff in- creased significantly and the peak discharge increased by approx- imately 100%. This was also the result when the entire cell was assumed to be bare ground. The potential for erosion of the soil at the base of the solar pan- els was also studied. It was determined that the kinetic energy of the water draining from the solar panel could be as much as 10 times greater than that of rainfall. Thus, because the energy of the water draining from the panels is much higher, it is very possible that soil below the base of the solar panel could erode owing to the concen- trated flow of water off the panel, especially if there is bare ground in the spacer section of the cell. If necessary, erosion control meth- ods should be used. Bare ground beneath the panels and in the spacer section is a realistic possibility (see Figs. 1 and 5). Thus, a good, well - maintained grass cover beneath the panels and in the spacer section is highly recommended. If gravel, pavement, or bare ground is 540 / JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 J. Hydrol. Eng. 2013.18:536-541. Downloaded from ascelibrary.org by University Of Massachusetts Amherst on 05/10/15. Copyright ASCE. For personal use only; all rights reserved. deemed unavoidable below the panels or in the spacer section, it may necessary to add a buffer section to control the excess runoff volume and ensure adequate losses. If these simple measures are taken, solar farms will not have an adverse hydrologic impact from excess runoff or contribute eroded soil particles to receiving streams and waterways. Acknowledgments The authors appreciate the photographs (Figs. 1 and 5) of Ortho Clinical Diagnostics, 1001 Route 202, North Raritan, New Jersey, 08869, provided by John E. Showler, Environmental Scientist, New Jersey Department of Agriculture. The extensive comments of reviewers resulted in an improved paper. References Bedient, P. B., and Huber, W. C. (2002). Hydrology and,floodplain analy- sis, Prentice -Hall, Upper Saddle River, NJ. Beuselinck, L., Govers, G., Hairsince, P. B., Sander, G. C., and Breynaert, M. (2002). "The influence of rainfall on sediment transport by overland flow over areas of net deposition." J. Hydrol., 257(1-4), 145-163. Dabney, S. M., Moore, M. T., and Locke, M. A. (2006). "Integrated man- agement of in -field, edge -of -field, and after -field buffers." J. Amer. Water Resour. Assoc., 42(1), 15-24. Engman, E. T. (1986). "Roughness coefficients for routing surface runoff." J. Irrig. Drain. Eng., 112(1), 39-53. Garde, R. J., and Raju, K. G. (1977). Mechanics of sediment transportation and alluvial stream problems, Wiley, New York. McCuen, R. H. (2005). Hydrologic analysis and design, 3rd Ed., Pearson/ Prentice -Hall, Upper Saddle River, NJ. Motha, J. A., Wallbrink, P. J., Hairsine, P. B., and Grayson, R. B. (2004). "Unsealed roads as suspended sediment sources in agricultural catch- ment in south-eastern Australia." J. Hydrol., 286(1-4), 1-18. Salles, C., Poesen, J., and Sempere-Torres, D. (2002). "Kinetic energy of rain and its functional relationship with intensity." J. Hydrol., 257(1-4), 256-270. Wischmeier, W. H., and Smith, D. D. (1978). Predicting rainfall erosion losses: A guide to conservation planning, USDA Handbook 537, U.S. Government Printing Office, Washington, DC. JOURNAL OF HYDROLOGIC ENGINEERING © ASCE / MAY 2013 / 541 J. Hydrol. Eng. 2013.18:536-541. t/5Rg3-00r7 Weld County Drainage Code Certificate of Compliance Weld County Case Number: Blue Spruce Solar Site Parcel Number: 105514300030 Legal Description, Section/Township/Range: A portion of the south west quarter of Section 14, Township 4 North, Range 65 West of the 6th P.M Date: 08/30/2023 Adam Harrison Consultant Engineer for CBEP Solar, LLC understand and acknowledge that the applicant is seeking land use approval of the case and parcel in the description above. I have designed or reviewed the design for the proposed land use set for in the application. I hereby certify, on behalf of the applicant, that the design will meet all applicable drainage requirements of the Weld County Code with the exception of the variances) described on the attached exhibits. This certification is not a guarantee or warranty either expressed or implied. Engineer's Stamp: (Applicant), Engineer of Record Signature Variance Request Of Applicable) 1. Describe the hardship for which the variance is being requested. 2. List the design criteria of the Weld County Code of which a variance is being requested. 3. Describe the proposed alternative with engineering rationale which supports the intent of the Weld County Code. Demonstrate that granting of the variance will still adequately protect public health, safety, and general welfare and that there are no adverse impacts from stormwater runoff to the public rights -of -way and/or offsite properties as a result of the project. T_h_e_addition of a detention pond on_siite will cause additio al Pia s n v -ianc +quest, Without a variance request there will need to be larger rade changes to a site that currently needs limited grading. Including stormwater detention on thes.project would require changing the existing sheetflow grades on the site to channelized flows directing runoff to a single location to be detained in a pond. A detention pond vi_ll require regular maintenance and upkeep impacting both the site development and increasinc the amount of traffic to and from the site over time. A variance is requested for Weld County Code 8-11-100 Storage using a detention pond. Weld County Drainaje Criteria includes 25% imperviousness for solar facilities for C and D soils. We will maintain overland sheet flow across the site, stormwater will not be concentrated nor will it exceed existing flows when it leaves the parcel. The areas with proposed solar arrays will be seeded with native vegetation a MHFD stormwater quality BMP, decreasing the peak flow rates from the existing tillage/agricultural land into heavy meadow land . Public Works Director/Designee Review Of.Applicable) • Me -1;5 ci,•_HS- Public Works Director/Designee Date of Signature Comments: Signature Appr :d O Denied Department of Public Works I Development Review 1111 H Street, Greeley, CO 80631 I Ph: 970-304-6496 I www.weldgov,com/departments/public_works/development_review 08/02/2019 CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 I N FO@CLOU DBREAKEN ERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Sewage Disposal Documentation No sewage disposal will be required for the operation of the Project. CBEP Solar 26, LLC or its contractor will provide portable toilets during construction. (970) 425-3175 I INFO©CLOUDBREAKENERGY.COM I CLOUDBREAKENERGY.COM CHAPTER 12 VARIANCE REQUESTS The County recognizes that in certain limited instances it may be exceptionally difficult to conform to the criteria set forth in this manual and the Weld County Code. The County will consider requests for variances on a case -by -case basis. The variance request will be submitted in a written attachment to the initial submittal of construction plans. Drainage variances require the use of a request form found on the County website. All other requests will consist of the following: 1. Identification of the criteria or Weld County Code section to be waived or varied 2. Identification of the construction criteria adhered to 3. Justification for the variance, which will demonstrate the following: • Hardship is created if the variance is not approved. • There will be only minimal impact on public safety. • The variance is not contrary to best engineering practices. a The variance is not contrary to the intent and general purpose of these criteria and the Weld County Code. • The variance does not result in a significant impact to the public due to maintenance of the improvement. • The variance does not result in a significant impact to the aesthetic appearance of the improvement. • The variance is the minimum exception from the criteria necessary to afford relief from the hardship. • The variance is reasonably necessary for the health, safety, and welfare of the public. The variance request will be prepared, stamped, signed, and dated by a professional civil engineer licensed to practice in the State of Colorado. Requests will be reviewed by the Public Works Director or his/her designee. The Public Works Director reserves the right to deny, or allow his or her designee to deny, any request for variance if doing so is in the interest of public health, safety, and welfare. WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1146 CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Dust Abatement Plan The purpose and intent of this Dust Abatement Plan is to ensure that the Project complies with applicable state and federal air quality standards. The Environmental Protection Agency (EPA) sets forth the National Ambient Air Quality Standards (NAAQs) pursuant to the Clean Air Act. Air quality impacts associated with construction projects generally arise from fugitive dust generation during the operation of heavy equipment. Colorado administers the NAAQS through issuance of the Air Pollutant Emission Notice (APEN). The Project will not exceed the NAAQS and will follow best management practices to ensure that the production of dust will be controlled by the regular application of water to the Project. The Project will obtain an APEN permit prior to construction. Minimal dust is expected to be generated during construction and operations due to the planned use of dust suppression best management practices and soil stabilization following construction and throughout operations. During construction, CBEP Solar 26, LLC and its contractors will control dust by applying water to disturbed soils and soil piles to control fugitive dust from blowing and impairing air quality. Once the construction phase is completed, the site will be visited 1-2 times per year for routine maintenance and as needed for emergency maintenance. Disturbed areas not covered with gravel as part of the Project design will be reseeded with native seed to revegetate disturbed areas and hold soil in place, minimizing fugitive dust impacts during operations. CBEP Solar 26, LLC would employ native revegetation methods or chemical control methods for infestations of weeds during regular maintenance if necessary. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Dust and Weed Mitigation Plan Dust Control: • Minimal dust is expected to be generated during construction and operations due to the planned use of dust suppression best management practices and soil stabilization following construction and throughout operations. During construction, CBEP Solar 26, LLC and its contractors will control dust by applying water to disturbed soils and soil piles to control fugitive dust from blowing and impairing air quality. • During the operations of the Project, the land under and around the Project will be seeded with a native grass seed mixture, which will mitigate dust. Weed Control: • The site will be inspected annually by CBEP Solar 26, LLC or its contractors for the presence of invasive species. Minor presences will be managed by cutting and pulling in a manner to not disburse or promote spreading of weed seeds. If a major presence occurs, mowing and the potential application of herbicides will be deployed. Herbicide selection may vary depending on the time of year, the life cycle of the noxious weed species. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Landscape and Screening Plan CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM There is currently no landscaping on the Project's site. The Project will be surrounded by a 7 -foot tall game fence. CBEP Solar 26, LLC will either get waivers from the nearby residences or plant Rocky Mountain Junipers along the outside of the western fence line to provide natural screening for nearby residences. Example photos as well as a map depicting the proposed location for tree placement are provided below. Please refer to sheet 4.0 of the USR Map for additional detail on the proposed security fence. CBEP Solar 26, LLC plans to work with Pawnee Buttes/Greencover to create a unique diversified seed mixture to be seeded within the Project Area and will utilize sheep grazing to maintain the land. EXAMPLE PHOTOS: r• a tar: r t'14.4:*-:°. 7 - cr. Pe 78 �. III -• 1. < J. J!1 A 1 ICI ,; li.y'�1�I I (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE 2 PROPOSED LOCATION FOP TREE PLACEMENT: (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOU DBREAKEN ERGY.COM CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: My 15, 2023 PROJECT: Blue Spruce Solar Project SUBJECT: Manure Management Plan CBEP Solar 26, LLC is proposing to construct and operate the Blue Spruce Solar Project in u nincorporated Weld County, Colorado. The Project includes the construction of 10 Megawatts (MW) of solar electric generation on a portion of a 152 -acre parcel. In addition to the solar array, the Project site will continue to contribute to the agricultural economy of Weld County by u sing the pasture land underneath the solar array for sheep grazing. This Manure Management Plan describes CBEP Solar 26, LLC's plan to maintain and minimize the impacts of the manure o n the Project parcel and neighboring community. Background: CBEP Solar 26, LLC intends to partner with a local shepherd that will be grazing no more than 500 sheep on the Blue Spruce Solar Project site for periods during the grazing season. The Blue Spruce Solar Project is one of many fields the flock of sheep will rotate between. These sheep will be processed in Weld County at Innovative Foods. Manure Load Management: Through rotational grazing and, if necessary, harrowing, the manure load will be evenly distributed across the parcel and have minimal impact on the neighboring community. Rotational Grazing: The shepherd will section off portions of the Project and graze the herd in the subsections, rotating the sheep to new subsections regularly. The shepherd will also rotate the herd between several Cloudbreak solar projects to manage the manure load and forage materials on the land. This will make the overall manure load very manageable and reduce the impact to surrounding properties. The herd will not stay permanently at the Blue Spruce Solar Project. The Project site will not serve as a feedlot for sheep. Harrowing: If necessary, a harrowing machine will be used on the Blue Spruce Solar Project site to spread out and break up the manure once the sheep move on to the next subsection or pasture. This machine will disturb the topsoil to help break down and bury the manure. Composting: If the manure load ever becomes problematic, CBEP Solar 26, LLC will physically remove the manure and compost it offsite. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM Kimley >>Horn May 10, 2023 Mr. Zach Brammer CloudBreak Energy Partners 218 S. 3rd Street Sterling, CO 80751 Re: CloudBreak — Michael Boulter Sound Study Weld County, Colorado Dear Mr. Brammer: Executive Summary The purpose of this technical memorandum is to summarize the evaluated sound levels associated with the operational equipment located at the proposed Michael Boulter Solar Site in Weld County, CO. The proposed solar photovoltaic project site is approximately 4 miles southeast of La Salle, approximately 6 miles southwest of Kersey, and approximately 5 miles southeast of downtown Evans. The site is generally located south of County Road 46, west of County Road 47, and east of County Road 45, and north of County Road 44. The solar site will be located on agricultural land with rural residential land uses located west, north, and east of the project area. The location of the proposed Michael Boulter Solar Site is shown in Figure 1. Analysis Findings • The solar photovoltaic project will be located on agricultural land with rural residential land uses west, north, and east of the project area. A noise goal of 55 dB(A) during daytime hours was established for this project. Unmitigated hourly equivalent operational noise levels are estimated to be below approximately 41 dB(A) during daytime hours at the closest noise -sensitive land uses west of the site. Additionally, the operational noise levels are anticipated to remain below the Weld County Charter and County Code maximum permissible noise level at residential property boundaries during daytime hours; therefore, noise mitigation is not recommended at this time. Project Description The proposed Michael Boulter Solar Site will be developed on approximately 85 acres of agricultural land in an unincorporated portion of Weld County, CO. The solar power generating facility will consist of rows of Photovoltaic Solar Modules, a gravel access driveway, and underground utilities. Seven (7) substations with an associated transformer and inverters will be located on site. Five (5) of the substations are located towards the northern portion of the site, and the remaining two (2) are near the southern portion of the site. kimley-horn.com 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>) Horn Figure 1: Site Location and Vicinity Michael Boulter Solar Site Sound Study May 10, 2023 - Page 2 County Roa County Road 44 C ui®.y_Road kimley-horn. corn 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn Michael Boulter Solar Site Sound Study May 10, 2023 - Page 3 Characteristics of Noise Noise is generally defined as unwanted sound. It is emitted from many natural and man-made sources. Sound pressure levels are usually measured and expressed in decibels (dB). The decibel scale is logarithmic and expresses the ratio of the sound pressure unit being measured to a standard reference level. Most sounds occurring in the environment do not consist of a single frequency, but rather a broad band of differing frequencies. The intensities of each frequency add together to generate sound. Because the human ear does not respond to all frequencies equally, the method commonly used to quantify environmental noise consists of evaluating all of the frequencies of a sound according to a weighting system. It has been found that the A -weighted decibel [dB(A)] filter on a sound level meter, which includes circuits to differentially measure selected audible frequencies, best approximates the frequency response of the human ear. The degree of disturbance from exposure to unwanted sound — noise — depends upon three factors: 1. The amount, nature, and duration of the intruding noise 2. The relationship between the intruding noise and the existing sound environment; and 3. The situation in which the disturbing noise is heard In considering the first of these factors, it is important to note that individuals have varying sensitivity to noise. Loud noises bother some people more than other people, and some individuals become increasingly upset if an unwanted noise persists. The time patterns and durations of noise(s) also affect perception as to whether or not it is offensive. For example, noises that occur during nighttime (sleeping) hours are typically considered to be more offensive than the same noises in the daytime. With regard to the second factor, individuals tend to judge the annoyance of an unwanted noise in terms of its relationship to noise from other sources (background noise). A car horn blowing at night when background noise levels are low would generally be more objectionable than one blowing in the afternoon when background noise levels are typically higher. The response to noise stimulus is analogous to the response to turning on an interior light. During the daytime an illuminated bulb simply adds to the ambient light, but when eyes are conditioned to the dark of night, a suddenly illuminated bulb can be temporarily blinding. The third factor situational noise — is related to the interference of noise with activities of individuals. In a 60 dB(A) environment such as is commonly found in a large business office, normal conversation would be possible, while sleep might be difficult. Loud noises may easily interrupt activities that require a quiet setting for greater mental concentration or rest; however, the same loud noises may not interrupt activities requiring less mental focus or tranquility. As shown in Figure 2, most individuals are exposed to fairly high noise levels from many sources on a regular basis. To perceive sounds of greatly varying pressure levels, human hearing has a non- linear sensitivity to sound pressure exposure. Doubling the sound pressure results in a three decibel change in the noise level; however, variations of three decibels [3 dB(A)] or less are commonly considered "barely perceptible" to normal human hearing. A five decibel [5 dB(A)] change is more readily noticeable. A ten -fold increase in the sound pressure level correlates to a 10 decibel [10 dB(A)] noise level increase; however, it is judged by most people as only sounding "twice as loud". kimley-horn. corn 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>) Horn Figure 2: Common Noise Levels Michael Boulter Solar Site Sound Study May 10, 2023 - Page 4 Kimley*) Horn Noise Source Jet Engine Police Siren Garbage Truck Motorcycle Drilling Vacuum Cleaner Air Conditioner Refrigerator Whisper Rustling Leaves Normal Breathing typical A -weighted sound levels in decibels. "A" weighting approximates the frequency response 01 the human ear. Common Environmental Noise Levels (18(A)* Noise Level Response Times As Loud Harmfully loud 128 —I Painfully loud v Regular exposer 7 A over 1 minute risks permanent hearing loss 85 80 75 70 65 60 55 50 45 Very loud Annoying - i nterferes • with conversation Moderately loud Comfortable 1/2 • 1/4 Quiet • 1/8 Very quiet Just audible Threshold of hearing Over time, individuals tend to accept the noises that intrude into their lives on a regular basis. However, exposure to prolonged and/or extremely loud noise(s) can prevent use of exterior and interior spaces and has been theorized to pose health risks. kimley-horn. corn 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn Michael Boulter Solar Site Sound Study May 101 2023 - Page 5 Local Regulations The Michael Boulter Solar Site is in Weld County, CO. Chapter 21, Article VII, Division 3 of the Weld County Charter and County Code describes the requirements for a permit for site selection of a solar energy facility and states that noise impacts must be analyzed. Chapter 14, Article IX of the Weld County Charter and County Code describes the noise regulations in Weld County, and Section 14-9-30 of this article states that a violation of this ordinance includes knowingly making, causing, or permitting to be made any excess noise or exceeding the sound levels provided in Section 14-9-40 of the Weld County Charter and County Code. The maximum permissible noise levels at different land uses are shown in Table 1. Table 1: Maximum Permissible Noise Levels Land Use Maximum 7:00 am Noise -9:00 [dB(A)] pm Maximum 9:00 pm Noise 7:00 [dB(A)] am Residential Property or Commercial Area 55 dB(A) 50 dB(A) Industrial Area or Construction Activities 80 dB(A) 75 dB(A) Nonspecified Areas 55 dB(A) 50 dB(A) The closest noise -sensitive receptors around the Michael Boulter Solar site are either residential or non -specified land uses. It should be noted that on -site operations are not anticipated to occur during nighttime hours and minimal operational noise will be produced; therefore, the daytime maximum permissible operational noise level of 55 dB(A) will be used. Noise Analysis Sound levels from the proposed Michael Boulter Solar Site were evaluated using SoundPLAN. This program computes predicted sound levels at noise -sensitive areas through a series of adjustments to reference sound levels. SoundPLAN can also account for topography, groundcover type, and intervening structures. Sound levels generated from inverters are anticipated to be the main source of sound from the proposed solar photovoltaic project site. It should be noted that noise from surrounding roadways was not modeled in this analysis, although County Road 45, County Road 47, County Road 44, County Road 46, and other rural roadways are anticipated to contribute to the ambient noise environment throughout the entire day. Inverters Photovoltaic (PV) inverter equipment generates steady, unvarying sound that can create issues when located near noise -sensitive areas. It was assumed that fifty-five (55) PV inverters would be located near the northern portion of the site, and twenty-two (22) PV inverters would be located near the southern portion of the site. Based on design specifications for the CPS SCH100/125KTL-DO/US-600 inverter, a reference sound level of 65 dB(A) at 1 meter for each PV inverter was used. The sound from the simultaneous operation of the PV inverter equipment was calculated at the closest noise - sensitive receptors surrounding the project area using SoundPLAN. kimley-horn. corn 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn Michael Boulter Solar Site Sound Study May 10, 2023 - Page 6 Sound generated by the inverters is not anticipated to significantly contribute to the existing environmental sound levels surrounding the site. Also, sound generated by the inverters is expected to be mitigated by providing sufficient offsets between the inverters and surrounding noise -sensitive land uses as well as by the physical presence of the solar arrays, which are anticipated to shield and disperse some of the sound generated by the inverters. Transformers Transformers also generate steady, unvarying noise that can create issues when located near noise - sensitive uses. It was assumed that five (5) transformers would be located at the proposed substations towards the northern portion of the site, and two (2) transformers would be located at the proposed substations towards the southern portion of the site. Each transformer was assumed to be located just north of their respective set of eleven (11) inverters. A reference sound level for a transformer of 79 dB(A) at 1 meter was used. The noise from the transformer operation at the substation was calculated at the at the noise -sensitive receptors in the area near the proposed substation using SoundPLAN. Noise generated from the transformer is not anticipated to significantly contribute to the operational project noise and is expected to be kept in control by distance to noise -sensitive receptors. Results The SoundPLAN-predicted maximum operational sound levels at the surrounding noise -sensitive land uses are anticipated to be below the Weld County Charter and County Code noise level limits. The anticipated operational sound contours are shown in Figure 3. kimley-horn. corn 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn Figure 3: Operational Sound Contours Michael Boulter Solar Site Sound Study May 10, 2023 - Page 7 Signs and symbols Levels in dB(A) 45 45 50 50 - 55 55 - 60 60 - 65 >=55 Conclusions The site is generally located south of County Road 46, west of County Road 47, and east of County Road 45, and north of County Road 44. The solar site will be located on agricultural land with rural residential land uses located west, north, and east of the project area. After modeling and analyzing the anticipated operational sound levels throughout the proposed solar site, it was determined that noise mitigation measures are not needed at this time since the anticipated operational sound levels will remain below the Weld County Charter and County Code allowable noise levels at the nearest noise -sensitive receptors around the site during daytime hours. kimley-horn. corn 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 KimIey*) Horn April 14, 2023 P repared For: Mr. Zach Brammer Cloudbreak Energy Partners P repared By: Jesse Carlson, Wildlife Biologist Kimley-Horn S ubject: Sensitive Species Memorandum Cloudbreak- Michael Boulter South Solar Site (42 acres) Weld County, Colorado Biological Resources Review Summary The purpose of this technical memorandum is to summarize the federal and state listed sensitive plant species, sensitive wildlife species, and other natural resources of concern associated with the proposed Michael Boulter South Solar Site in Weld County, Colorado. The sensitive species desktop review conducted by Kimley-Horn resulted in the following key takeaways: • Based on aerial imagery, there is a low likelihood of suitable habitat for United States Fish and Wildlife Service (USFWS) Endangered Species Act (ESA) listed species. Kimley-Horn recommends a habitat suitability site survey for listed species prior to development activities. • There are no federally designated critical habitats for ESA listed species within the project area. • There are no CPW seasonal closures, restrictions, or limitations for big game or other wildlife species mapped within the project area. • The project area is mapped as intersecting black -tailed prairie dog (Cynomys ludovicianus) "colony potential occurrence" and "overall range". If live prairie dogs n eed to be relocated away from the project area, a Colorado Parks and Wildlife (CPW) application is required. No permit is required to transport dead prairie dogs to a wildlife rehabilitator for donation. • There are two mapped Swainson's hawk (Buteo swasoni) nests located within 1.0 - mile of the project area. One "destroyed" nest is located approximately 0.7 mile n ortheast and one "inactive" nest is located approximately 0.9 mile west. Though these n ests do not intersect a protected CPW buffer, pre -construction raptor nest surveys are still recommended if disturbance activities are to occur during the raptor nesting season (November 15 — October 31). • There is a moderate likelihood of suitable habitat for migratory birds protected under the Migratory Bird Treaty Act (MBTA). Pre -construction migratory bird nest surveys are recommended if disturbance activities are to occur during the nesting season (April I —August 31). kimley-horn.corn 1125 17th Street, Suite 1400, Denver, Co 80202 303 228 2300 Kimley>>> Horn Sensitive Species Memorandum Michael Boulter South Solar Site P roject Description The proposed solar photovoltaic project area is approximately 4.5 miles southeast of LaSalle and approximately 6.5 miles southwest of Kersey. The site is generally located north of County Road 44 and east of County Road 45. The solar site will be located on disturbed rangeland. The location of the proposed Michael Boulter South Solar Site is shown in Figure 1. The proposed Michael Boulter South Solar Site will be developed on approximately 42 acres of private land in an unincorporated portion of Weld County, CO. The solar power generating facility will consist of rows of Photovoltaic Solar Modules, gravel access driveways, associated electrical equipment, underground utilities, and a substation. P roject Setting The project lies within the Flat to Rolling Plains (25d) Sub -Region of the High Plains Ecoregion. Based on aerial imagery (June 2021), the project is situated in a disturbed rangeland setting. The project is bound to the north and east by agriculture and oil and gas activity, to the south by County Road 44, and to the west by County Road 45. Based on the N ational Land Cover Database (NLCD), the project area consists of herbaceous, cultivated crops, emergent herbaceous wetlands, and developed — open space land cover types (Figure 2). kimley-horn.corn 1125 17th St, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn Figure 1. Vicinity Map Sensitive Species Memorandum Michael Boulter South Solar Site magery Date/ Source: Esri, 2023; Land Characterizations: @LIB{ 2023; Hydrology/ NM: USFWS, 2022; Critical Habitat: USFWSJ 2023 County Road 45 V Koala 44 Legend USFWS Critical Habitat NWI Mapped Wetlands & Streams Private Land Project Limits LI 0.06 0.13 0.25 Miles Vicinity Map 44 Michael Boulter South Property Weld County, Colorado CLOUDBREAK Kimley: Horn =nonrl Mn:r Experinmcn Bellrr. kimley-horn.corn 1125 17th St, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn Figure 2. National Land Cover Database Map Sensitive Species Memorandum Michael Boulter South Solar Site Land Cover (NLCD 2016) • • • U Barren Land Cultivated Crops Deciduous Forest Developed, High Intensity Developed, Low Intensity Developed, Medium Intensity Developed, Open Space Emergent Herbaceous Wetlands INEvergreen Forest ■ ■ • ■ • Hay/Pasture Herbaceous Mixed Forest Open Water Perennial Snow/Ice Shrub/Scrub Woody Wetlands U Natural Resources Several geospatial databases were reviewed for federal and state natural resources of concern. These databases include: • Colorado Conservation Data Center (CODEX) o CODEX database includes information from: ■ Bird Conservancy of the Rockies ■ Colorado Natural Heritage Program ■ CPW ■ NLCD ■ NatureServe ■ USFWS • CPW Mapped Raptor Nest Database (Public Access Restricted) • CPW Preble's Meadow Jumping Mouse Trapping Database (Public Access Restricted) • CPW Species Activity Mapping (SAM) • USFWS Information for Planning and Consultation (IPaC) • USFWS National Wetlands Inventory Database Federally Listed Species Kimley-Horn obtained an official species list from the USFWS IPaC system on April 4, 2023. The list includes nine (9) threatened, endangered, or candidate species as potentially occurring within the project area. There are no federally designated critical habitats within the project area. Based on aerial imagery, there is a low likelihood of suitable habitat for USFWS IPaC listed species. Kimley-Horn recommends a habitat suitability site survey for USFWS IPaC listed species prior to development activities. kimley-horn.corn 1125 17th St, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn Sensitive Species Memorandum Michael Boulter South Solar Site State Listed Species Kimley-Horn consulted the CPW SAM database for documented wildlife species and their seasonal uses within the project area on April 10, 2023. There are no CPW seasonal closures, restrictions, or limitations for big game or other wildlife species mapped within the project area. Black -tailed prairie dog "colony potential occurrence" and "overall range" are mapped as intersecting the project area. If live prairie dogs need to be relocated away from the project area, a CPW application is required. No permit is required to transport dead prairie dogs to a wildlife rehabilitator for donation. Migratory Birds and Raptors There have been several hundred documented species of migratory birds in Colorado, and they are well -adapted to a variety of habitats. Migratory birds may nest on the ground, on structures, or in trees, shrubs, or other vegetation within the project area. All birds in Colorado are protected under the MBTA, except for nonnative species such as house sparrows (Passer domesticus) and rock doves (Columba livia) (USFWS 2020). Based on aerial imagery, there is a moderate likelihood of suitable migratory bird habitat within the project area. Pre - construction migratory bird nest surveys are recommended if disturbance activities are to occur during the nesting season (April 1 — August 31). All raptor species are protected in Colorado. There are various CPW development buffers for raptor nests depending on the type of raptor species and disturbance activity. CPW publishes a mapped raptor nest geospatial database. Two raptor nests were mapped within 1.0 mile of the project area. The first nest is located approximately 0.7 mile northeast of the project area and was classified as a "destroyed" Swainson's hawk nest last surveyed in April of 2019. The second nest is located approximately 0.9 mile west of the project area and was classified as an "inactive" Swainson's hawk nest last surveyed in April of 2019. For Swainson's hawks, CPW recommends "no surface occupancy (beyond that which historically occurred in the area) within 1 mile radius of active nests. No permitted, authorized, or human encroachment activities within 1/4 mile radius of active nests". The CPW raptor nest database is typically accurate at representing the location of historic raptor nests; however, it is often not up-to- date or all -encompassing. Though the nests do not intersect a protected CPW buffer, pre - construction raptor nest surveys are still recommended if disturbance activities are to occur during the nesting season (November 15 — October 31). Environmental Permitting Summary Federally regulated resource concerns on site are limited to potentially suitable nesting habitat for migratory bird species. Impacts to this resource are anticipated to be avoidable through appropriate pre -construction surveys. No associated permitting is anticipated to be needed with USFWS or CPW. There is no federal nexus for the project (e.g. no federal funding, no federal lands and no federal permits); accordingly, compliance with the National Environmental Policy Act is not applicable. The site lies within Federal Emergency Management Agency Flood Zone X and is in panel #08123C1750E (effective 1/20/2016). Flood Zone X consists of areas with a 0.2% annual kimley-horn.corn 1125 17th St, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn Sensitive Species Memorandum Michael Boulter South Solar Site chance of flooding and areas with otherwise minimal risk of flooding. Floodplain permitting is not applicable to the project. The project will not require a point source water discharge permit. It is expected that a Stormwater Management Plan will be required to protect affected drainage systems and to ensure stormwater runoff meets the Colorado Department of Public Health and Environment (CDPHE) Water Quality Control Division (WQCD) standards. A general permit number C0G080000 with the CDPHE WQCD may also be required during application to the county. The new general permit number C0G080000 has been developed to authorize short-term discharges of source water that comes in contact with short-term construction activities to waters of the state. The project location in Weld County is in attainment with the National Ambient Air Quality Standards for NO2, PM2.5, PM -10, SO2, Pb, and 1 -hour Ozone (O3). The Proposed Project location is considered non -attainment for the 8 -hour O3 standard and a maintenance area for the CO standard according to the EPA's current Green Book and the CDPHE (USEPA 2023). Best practices during construction activities should be followed to minimize combustion of gas and emissions of hydrocarbons in the atmosphere. Air quality permitting is limited to a Land Development Air Pollution Emissions Notice (APEN) with CDPHE. Best Management P ractices associated with the APEN will be incorporated into project design. P lease contact me at (720) 295-6923 orjesse.carlson@kimley-horn.com should you have any questions. S incerely, Jesse Carlson Wildlife Biologist Attachments: • Federal and State Listed Species Mapped within the Project Area • USFWS IPaC Report References U nited States Environmental Protection Agency. 2023. Green Book. Available at: https://www3.epa.gov/airquality/greenbook/anayo co.html U nited States Fish and Wildlife Service (USFWS). 2020. List of Bird Species to Which the Migratory Bird Treaty Act Does Not Apply. Accessed at: https://www.federalreg ister.gov/documents/2020/04/1 6/2020-06782/list-of-bird-species-to- which-the-m ig ratory-bird-treaty-act-does-not-apply kimley-horn.com 1125 17th St, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn FEDERAL AND STATE LISTED SPECIES MAPPED WITHIN THE PROJECT AREA Kimley>>>Horn United States Fish and Wildlife Information for Planning and Consultation Listed Species Mapped within the Project Area Species Conservation Status Potential Project to Occur Area in (Laterallus jamaicensis) jamaicensis Black Rail ssp. Low Eastern Threatened Gray Wolf (Canis lupus) Endangered Low (Danaus Monarch plexippus) Butterfly Candidate Low (Scaphirhynchus Pallid Sturgeon albus) Endangered Low (Charadrius Piping Plover melodus) Low Threatened Preble's (Zapus Meadow Jumping hudsonius preblei) Mouse Threatened Low Ute (Spiranthes Ladies' -tresses diluvialis) Low Threatened Western (Platanthera Prairie Fringed praeclara) Orchid Threatened Low Whooping (Grus Crane americanus) Endangered Low Eastern Black Rail (Laterallus jamaicensis spp. jamaicensis) Eastern black rail, a threatened bird species, is found in both coastal and interior areas of the eastern United States, but the majority of detections are from coastal sites. Rails that reside in Colorado are known to migrate to Texas to overwinter and, as such, are typically only encountered in Colorado during the spring and summer. These birds are wetland dependent, requiring dense overhead cover and soils that are moist to saturated (occasionally dry) and interspersed with or adjacent to very shallow water (typically ≤ 3 cm) to support their resource needs. Critical habitat has not been designated for this species (USFWS 2019). This species is known to occur in Weld County, Colorado; however, there is no suitable habitat based on aerial imagery. No impacts to this species are anticipated. Gray Wolf (Canis lupus) Gray wolf, an endangered mammal species, is an adaptive species that can thrive in a variety of habitats. The historical range for this species covered much of the continental United States, including Colorado (USFWS 2023a). However, this species was eradicated from Colorado in the 1940's due to shooting, trapping, and poisoning. The United States Fish and Wildlife Service (USFWS) has restored gray wolf populations in Colorado's neighboring states over the past decade and there have been occasional wolf migrants observed in Colorado. The current range is limited to a few individual animals located in north -central Colorado counties that share a border with Wyoming (CPW 2022). Gray wolves should be considered in the effect analysis only if the project in question has a predator management program. The proposed project does not include a predator management program; therefore, no impacts to this species are anticipated. Kimley>>> Horn Monarch Butterfly (Danaus plexippus) Monarch butterfly, a candidate insect species, is a migratory species that is found in North America. Monarchs breed throughout most of the United States and southern Canada and overwinters in central Mexico. The monarch butterfly requires milkweed (Asclepias sp.) for survival. Adult monarchs feed on the nectar of flowering milkweed, and larvae require milkweed as a host plant (USFWS 2023b). Consultation with USFWS under section 7 of the Endangered S pecies Act (ESA) is not required for candidate species, like the monarch butterfly. No impacts to this species are anticipated. P reble's Meadow Jumping Mouse (Zapus hudsonius preblei) The Preble's meadow jumping mouse is a nocturnal mouse that occupies the eastern edges of the Front Range in Colorado. Habitat for Preble's is typically comprised of well -developed riparian vegetation with adjacent, relatively undisturbed grassland communities and a nearby water source (USFWS 2023c). Preble's riparian habitats are close to creeks, typically within the 100 - year floodplain, and feature dense, multi -story horizontal cover of shrubs and trees with an u nderstory of forbs and grasses. Upland habitats are usually immediately adjacent to the riparian habitats or within 300 feet of the 100 -year floodplain. The USFWS has designated critical habitat, as well as block clearance area for this species. Block clearance areas are portions of land where P reble's meadow jumping mouse ESA precautions are no longer necessary. The project area is o utside of critical habitat and is not within a block clearance area for this species. Colorado Parks and Wildlife (CPW) publishes a Preble's meadow jumping mouse trapping location database. There are no trapping events in or near the project area. The closest trapping event is located approximately 3.8 miles northwest of the project area. No mice were trapped at this location. This species is known to occur in Weld County, Colorado; however, there is no suitable habitat based o n aerial imagery. No impacts to this species are anticipated. Ute Ladies' -tresses (Spiranthes diluvialis) Ute ladies' -tresses, a threatened orchid species, occurs near the base of the eastern slope of the Rocky Mountains in southeastern Wyoming and Nebraska and north -central and central Colorado. The species prefers habitat dominated by low vegetative cover associated with floodplains, perennial stream terraces, and oxbows. Critical habitat has not been designated for the species (USFWS 2023d). The flowering period for this species is between July and September. This species is known to occur in Weld County, Colorado; however, there is no suitable habitat based on aerial imagery. No impacts to this species are anticipated. Western Prairie Fringed Orchid (Platanthera praeclara) The Western prairie fringed orchid, a federally threatened orchid species, is mapped by the U SFWS as occurring in Colorado east of the Continental Divide, from south of Colorado Springs to the northern border with Wyoming. The orchid species occurs in mesic to wet unplowed tallgrass prairies and meadows but has been found in old fallow fields and roadside ditches. This species flowers from mid -June through early July. Based on aerial imagery, the project area is comprised of disturbed uplands and lacks the wetland component required for this species. The project is also surrounded by human disturbance. Critical habitat has not been designated for the species (USFWS 2023e). This species is known to occur in Weld County, Colorado; however, there is no suitable habitat based on aerial imagery. No impacts to this species are anticipated. Kimley*>Horn Whooping Crane (Grus americanus) The whooping crane breeds, migrates, winters, and forages in a variety of wetland and other habitats, including coastal marshes and estuaries, inland marshes, lakes, ponds, wet meadows and rivers, and agricultural fields. Whooping cranes breed and nest in wetland habitat in Wood - Buffalo National Park, Canada. Bulrush is the dominant vegetation type in the potholes used for nesting, although cattail, sedge, musk -grass, and other aquatic plants are common. Nest sites are primarily located in shallow diatom ponds that contain bulrush. During migration, whooping cranes use a variety of habitats; however, wetland mosaics appear to be the most suitable. For feeding, whooping cranes primarily use shallow, seasonally and semi permanently flooded palustrine wetlands for roosting, and various cropland and emergent wetlands. In Nebraska, whooping cranes also often use riverine habitats. Wintering habitat in the Aransas National Wildlife Refuge, Texas, includes salt marshes and tidal flats on the mainland and barrier islands, dominated by salt grass, saltwort, smooth cordgrass, glasswort, and sea ox -eye (USFWS 2023f). This species is known to occur in Weld County, Colorado; however, there is no suitable habitat based on aerial imagery. No impacts to this species are anticipated. An additional two (2) listed species identified in the IPaC documentation should be considered in the effect analysis if water -related activities or use occur in the North and South Platte and Laramie River Basins as they may affect listed species in Nebraska (USFWS 2023g and USFWS 2023h). These species include the piping plover (Charadrius melodus) and pallid sturgeon (Scaphirhynchus albus). Colorado Parks and Wildlife Species Activity Map Listed Species within the Project Area Species Seasonal Use Black (Cynomys -tailed ludovicianus) Prairie Dog Colony Potential Overall Range Occurrence (Eptesicus Big Brown fuscus) Bat Overall Range (Pituophis Bull Snake catenifer sayi) Overall Range Canada Geese (Branta canadensis) Foraging Winter Area Range Common Garter (Thamnophis Snake sirtalis) Overall Range Common (Holbrookia Lesser Earless Lizard Overall Range maculate) Hernandez's Short (Phrynosoma -horned hernandesi) Lizard Overall Range (Lasiurus Hoary cinereus) Bat Overall Range Little (Myotis Brown lucifungus) Myotis Overall Range (Plestiodon Many -lined Skink multivirgatus) Overall Range (Lam propeltis Milk Snake triangulum) Overall Range (Odocoileus Mule Deer hemionus) Overall Range A-4 Kimley>>> Horn Species Seasonal Use North (Coluber American constrictor) Racer Overall Range Northern (Nerodia Watersnake sipedon) Overall Range Olive -backed (Perognathus Pocket fasciatus) Mouse Overall Range Ornate (Terrapene Box ornata ornata) Overall Range Turtle (Chrysemys Painted Turtle picta) Overall Range Plains (Tantilla Black -headed Snake nigriceps) Overall Range Plains Gartner Snake (Thamnophis radix) Overall Range Plains (Heterodon Hog -nosed Snake nasicus) Overall Range (Sceloporus Plateau Fence tristichus) Lizard Overall Range (Sceloporus Prairie Lizard undulatus) Overall Range Prairie (Crotalus Rattlesnake viridi) Overall Range Preble's (Zapus Meadow hudsonius Jumping preblei) Mouse Overall Range (Lasiurus Red Bat borealis) Overall Range Ring-necked (Phasianus colchicus) Pheasant Overall Range (Lasionycteris Silver -haired noctivagans) Bat Overall Range Six -lined (Aspidoscelis Racerunner sexlineata) Overall Range Snapping (Chelydra serpentine) Overall Range Turtle Spiny (Apalone Softshell spinifera) Overall Range Turtle (Thamnophis Garter Snake elegans) Overall Range Terrestrial (Perimyotis subflavus) Bat Overall Range Tri-colored Variable (Plestiodon multivirgatus Skink epipleurotus) Overall Range Western (Crotalus Rattlesnake atrox) Overall Range White-tailed (Odocoileus virginianus) Deer Overall Range White-tailed (Lepus townsendii) Jackrabbit Overall Range Kimley>>> Horn References Colorado Parks and Wildlife (CPW). 2022. Wolf Management. Available at: https://cpw.state.co.us/learn/Pages/CON-Wolf-Management.aspx U nited States Fish and Wildlife Service (USFWS). 2019. Species status assessment report for the eastern black rail (Laterallusjamaicensisjamaicensis), Version 1.3 August 2019. Atlanta, GA U SFWS. 2023a. Gray Wolf (Canis lupus). Available at: https://ecos.fws.gov/ecp/species/4488 U SFWS. 2023b. Monarch Butterfly (Danaus plexippus). Available at: https://ecos.fws.gov/ecp/species/9743 U SFWS. 2023c. Preble's meadow jumping mouse (Zapus hudsonius preblei). Available at: https://ecos.fws.gov/ecp/species/4090 U SFWS. 2023d. Ute Ladies' -tresses (Spiranthes diluvialis). Available at: https://ecos.fws.gov/ecp/species/2159 U SFWS. 2023e. Western prairie fringed orchid (Platanthera praeclara). Available at: https://ecos.fws.gov/ecp/species/1 669 U SFWS. 2023f. Whooping crane (Grus americanus). Available at: https://ecos.fws.gov/ecp/species/758 U SFWS. 2023g. Pallid Sturgeon (Scaphirhychus albus). Available at: https://ecos.fws.gov/ecp/species/7162 U SFWS. 2023h. Piping Plover (Chardarius melodus). Available at: https://ecos.fws.gov/ecp/species/6039 United States Department of the Interior FISH AND WILDLIFE SERVICE Colorado Ecological Services Field Office Denver Federal Center P.O. Box 25486 Denver, CO 80225-0486 Phone: (303) 236-4773 Fax: (303) 236-4005 In Reply Refer To: Project Code: 2023-0064590 Project Name: Michael Boulter - South 1F M.'.. F1si:1 ao WILIJL1If sr-in's t April 04, 2023 Subject: List of threatened and endangered species that may occur in your proposed project location or may be affected by your proposed project To Whom It May Concern: The enclosed species list identifies threatened, endangered, proposed and candidate species, as well as proposed and final designated critical habitat, that may occur within the boundary of your proposed project and/or may be affected by your proposed project. The species list fulfills the requirements of the U.S. Fish and Wildlife Service (Service) under section 7(c) of the Endangered Species Act (Act) of 1973, as amended (16 U.S.C. 1531 et seq.). New information based on updated surveys, changes in the abundance and distribution of species, changed habitat conditions, or other factors could change this list. Please feel free to contact us if you need more current information or assistance regarding the potential impacts to federally proposed, listed, and candidate species and federally designated and proposed critical habitat. Please note that under 50 CFR 402.12(e) of the regulations implementing section 7 of the Act, the accuracy of this species list should be verified after 90 days. This verification can be completed formally or informally as desired. The Service recommends that verification be completed by visiting the ECOS-IPaC website at regular intervals during project planning and implementation for updates to species lists and information. An updated list may be requested through the ECOS-IPaC system by completing the same process used to receive the enclosed list. The purpose of the Act is to provide a means whereby threatened and endangered species and the ecosystems upon which they depend may be conserved. Under sections 7(a)(1) and 7(a)(2) of the Act and its implementing regulations (50 CFR 402 et seq.), Federal agencies are required to utilize their authorities to carry out programs for the conservation of threatened and endangered species and to determine whether projects may affect threatened and endangered species and/or designated critical habitat. A Biological Assessment is required for construction projects (or other undertakings having similar physical impacts) that are major Federal actions significantly affecting the quality of the human environment as defined in the National Environmental Policy Act (42 U.S.C. 4332(2) 04/04/2023 2 (c)). For projects other than major construction activities, the Service suggests that a biological evaluation similar to a Biological Assessment be prepared to determine whether the project may affect listed or proposed species and/or designated or proposed critical habitat. Recommended contents of a Biological Assessment are described at 50 CFR 402.12. If a Federal agency determines, based on the Biological Assessment or biological evaluation, that listed species and/or designated critical habitat may be affected by the proposed project, the agency is required to consult with the Service pursuant to 50 CFR 402. In addition, the Service recommends that candidate species, proposed species and proposed critical habitat be addressed within the consultation. More information on the regulations and procedures for section 7 consultation, including the role of permit or license applicants, can be found in the "Endangered Species Consultation Handbook" at: http://www.fws.gov/endangered/esa-library/pdf/TOC-GLOS.PDF Migratory Birds: In addition to responsibilities to protect threatened and endangered species under the Endangered Species Act (ESA), there are additional responsibilities under the Migratory Bird Treaty Act (MBTA) and the Bald and Golden Eagle Protection Act (BGEPA) to protect native birds from project -related impacts. Any activity, intentional or unintentional, resulting in take of migratory birds, including eagles, is prohibited unless otherwise permitted by the U.S. Fish and Wildlife Service (50 C.F.R. Sec. 10.12 and 16 U.S.C. Sec. 668(a)). For more information regarding these Acts see https://www.fws.gov/birds/policies-and-regulations.php. The MBTA has no provision for allowing take of migratory birds that may be unintentionally killed or injured by otherwise lawful activities. It is the responsibility of the project proponent to comply with these Acts by identifying potential impacts to migratory birds and eagles within applicable NEPA documents (when there is a federal nexus) or a Bird/Eagle Conservation Plan (when there is no federal nexus). Proponents should implement conservation measures to avoid or minimize the production of project -related stressors or minimize the exposure of birds and their resources to the project -related stressors. For more information on avian stressors and recommended conservation measures see https://www.fws.gov/birds/bird-enthusiasts/threats-to- birds.php. In addition to MBTA and BGEPA, Executive Order 13186: Responsibilities of Federal Agencies to Protect Migratory Birds, obligates all Federal agencies that engage in or authorize activities that might affect migratory birds, to minimize those effects and encourage conservation measures that will improve bird populations. Executive Order 13186 provides for the protection of both migratory birds and migratory bird habitat. For information regarding the implementation of Executive Order 13186, please visit https://www.fws.gov/birds/policies-and-regulations/ executive-orders/e0-13186.php. php. We appreciate your concern for threatened and endangered species. The Service encourages Federal agencies to include conservation of threatened and endangered species into their project planning to further the purposes of the Act. Please include the Consultation Code in the header of this letter with any request for consultation or correspondence about your project that you submit to our office. 04/04/2023 3 Attachment(s): ■ Official Species List 04/04/2023 1 OFFICIAL SPECIES LIST This list is provided pursuant to Section 7 of the Endangered Species Act, and fulfills the requirement for Federal agencies to "request of the Secretary of the Interior information whether any species which is listed or proposed to be listed may be present in the area of a proposed action". This species list is provided by: Colorado Ecological Services Field Office Denver Federal Center P.O. Box 25486 Denver, CO 80225-0486 (303) 236-4773 04/04/2023 2 PROJECT SUMMARY Project Code: 2023-0064590 Project Name: Michael Boulter - South Project Type: New Constr - Above Ground Project Description: Site Analysis Project Location: The approximate location of the project can be viewed in Google Maps: https:// www.google.com/maps/@40.31003195,-104.63499076351947,14z -r Counties: Weld County, Colorado 04/04/2023 3 ENDANGERED SPECIES ACT SPECIES There is a total of 9 threatened, endangered, or candidate species on this species list. Species on this list should be considered in an effects analysis for your project and could include species that exist in another geographic area. For example, certain fish may appear on the species list because a project could affect downstream species. Note that 3 of these species should be considered only under certain conditions. IPaC does not display listed species or critical habitats under the sole jurisdiction of NOAA Fisheriesl, as USFWS does not have the authority to speak on behalf of NOAA and the Department of Commerce. See the "Critical habitats" section below for those critical habitats that lie wholly or partially within your project area under this office's jurisdiction. Please contact the designated FWS office if you have questions. 1. NOAA Fisheries, also known as the National Marine Fisheries Service (NMFS), is an office of the National Oceanic and Atmospheric Administration within the Department of Commerce. MAMMALS NAME Gray Wolf Canis lupus Population: U.S.A.: All of AL, AR, CA, CO, CT, DE, FL, GA, IA, IN, IL, KS, KY, LA, MA, MD, ME, MI, MO, MS, NC, ND, NE, NH, NJ, NV, NY, OH, OK, PA, RI, SC, SD, TN, TX, VA, VT, WI, and WV; and portions of AZ, NM, OR, UT, and WA. Mexico. There is final critical habitat for this species. This species only needs to be considered under the following conditions: ■ Lone, dispersing gray wolves may be present throughout the state of Colorado. If your activity includes a predator management program, please consider this species in your environmental review. Species profile: https://ecos.fws.gov/ecp/species/4488 Preble's Meadow Jumping Mouse Zapus hudsonius preblei There is final critical habitat for this species. Your location does not overlap the critical habitat. Species profile: https://ecos.fws.gov/ecp/species/4090 General project design guidelines: https://ipac.ecosphere.fws.gov/proj ect/MZM657PVMFA5JMWL 5VNZ3H6TJ4/documents/ generated/6861.pdf STATUS Endangered Threatened 04/04/2023 4 BIRDS NAME Eastern Black Rail Laterallus jamaicensis ssp. jamaicensis No critical habitat has been designated for this species. Species profile: https://ecos.fws.gov/ecp/species/10477 Piping Plover Charadrius melodus Population: [Atlantic Coast and Northern Great Plains populations] - Wherever found, except those areas where listed as endangered. There is final critical habitat for this species. Your location does not overlap the critical habitat. This species only needs to be considered under the following conditions: ■ Project includes water -related activities and/or use in the N. Platte, S. Platte, and Laramie River Basins which may affect listed species in Nebraska. Species profile: https://ecos.fws.gov/ecp/species/6039 Whooping Crane Grus americana Population: Wherever found, except where listed as an experimental population There is final critical habitat for this species. Your location does not overlap the critical habitat. Species profile: hops://ecos.fws.gov/ecp/species/758 FISHES NAME STATUS Threatened Threatened Pallid Sturgeon Scaphirhynchus albus No critical habitat has been designated for this species. This species only needs to be considered under the following conditions: • Project includes water -related activities and/or use in the N. Platte, S. Platte, and Laramie River Basins which may affect listed species in Nebraska. Species profile: https://ecos.fws.gov/ecp/species/7162 INSECTS NAME Endangered STATUS Endangered Monarch Butterfly Danaus plexippus No critical habitat has been designated for this species. Species profile: https://ecos.fws.gov/ecp/species/9743 FLOWERING PLANTS NAME Ute Ladies' -tresses Spiranthes diluvialis No critical habitat has been designated for this species. Species profile: https://ecos.fws.gov/ecp/species/2159 Western Prairie Fringed Orchid Platanthera praeclara No critical habitat has been designated for this species. Species profile: https://ecos.fws.gov/ecp/species/1669 STATUS Candidate STATUS Threatened Threatened 04/04/2023 5 CRITICAL HABITATS THERE ARE NO CRITICAL HABITATS WITHIN YOUR PROJECT AREA UNDER THIS OFFICE'S JURISDICTION. 04/04/2023 6 IPAC USER CONTACT INFORMATION Agency: Name: Address: City: State: Zip: Email Phone: Kimley-Horn Jesse Carlson 380 Interlocken Crescent Suite 100 Broomfield CO 80021 jesse .carlsonkimley-horn. com 2532982432 KimIey) Horn May 3, 2023 Mr. Zach Brammer CloudBreak Energy Partners, LLC 218 S. 3rd Street Sterling, Colorado 80751 Re: CloudBreak - Boulter Solar Traffic Study Letter Weld County, Colorado Dear Mr. Brammer: This traffic study letter has been prepared for the proposed CloudBreak - Boulter Solar project located in Weld County, Colorado. The purpose of this letter is to provide trip generation, trip distribution, and project traffic assignment for the construction phase of the proposed solar project to determine the anticipated increase in traffic attributable to the proposed project. The proposed development is located on the northeast corner of the intersection of Weld County Road 44 (WCR-44) and WCR-45. A vicinity map illustrating the location of CloudBreak - Boulter Solar is attached as Figure 1. The project will consist of a 10.0 MW solar facility with supporting infrastructure. A conceptual site plan for the proposed development is attached. This traffic study identifies the amount of traffic associated with this proposed development during both construction and operational phases, and the expected trip distribution and traffic assignment. CONSTRUCTION ACTIVITY AND ACCESS Construction activity to assemble the entire solar facility is anticipated to commence Quarter 1 of 2024. The construction activities each month may vary based on phasing and the size of the phase. This traffic study was prepared analyzing the peak construction traffic during the highest months of activity. Construction will generally follow these steps: • Mobilization • Civil/site preparation • Cable plow/foundations construction • Post install • Racking install • Substation construction • Set major equipment • Module installation • Testing, commissioning, and energization • Demobilization Regional access to CloudBreak - Boulter Solar will be provided by US -85, US -34, and WCR- 49. Primary access will be provided by WCR-45 while direct access is proposed from one full movement access along the east side of WCR-45. kimley-horn.com 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn CloudBreak — Boulter Traffic Study Letter Page 2 The anticipated truck routes to CloudBreak - Boulter Solar is via US -85, US -34, and WCR- 49. The anticipated truck route to the site from US -85 is to travel east on 37th Street, south along WCR-43, east along WCR-44, then north onto WCR-45, then east into the project site access. Truck trips to and from Greeley are also anticipated to utilize US -34, WCR-49, westbound along WCR-44, and northbound WCR-45 to the site access. Figure 2 illustrates the truck routes to and from the site. TRIP GENERATION Site -generated traffic estimates are determined through a process known as trip generation. The number of trips for the CloudBreak - Boulter Solar facility was based on anticipated construction activity and operations. In order to study the effect of construction traffic created by the solar facility, the expected trips during the peak period of construction were used as the basis for this study. The peak construction traffic activity is anticipated to occur in 2024. Construction Traffic Generation The typical construction peak season workday will see workers arriving during a four-hour window between 6:00 am and 10:00 am and departing during a three-hour window between 1:00 pm and 4:00 pm. The standard construction hours are anticipated to be 6:30 am to 3:30 pm. The highest proportion of workers will arrive to the site between 6:00 and 7:00 am (half) and depart between 3:00 pm to 4:00 pm (one-third), although the volume will be fairly uniform during the arrival and departure hours. It is anticipated that construction of the facility will include a maximum of 20 construction workers. It is important to note the truck trip generation also includes the volume adjusted for the three (3) passenger car equivalents (PCE) per truck. The following Table 1 identifies the peak construction activity trip generation for the construction of CloudBreak - Boulter Solar facility. Table 1 Trip Generation: CloudBreak Boulter Solar Development Weekday Vehicles Trips User Daily Round Daily AM Peak Hour PM Peak Hour Trips Trips In Out Total In Out Total 5 15 10 30 3 9 0 0 3 9 0 0 2 6 2 6 Heavy PCE Trips Duty Trucks (5) Passenger Vehicles (20) 20 40 10 0 10 0 7 7 Total Vehicles 25 35 50 70 13 19 0 0 13 19 0 0 13 9 13 9 Total PCE As shown in the table above, CloudBreak - Boulter Solar is expected to generate approximately 50 daily trips (25 round trips) with 13 of these trips occurring in the morning peak hour and nine (9) of these trips occurring in the afternoon peak hour during the peak construction activities. This volume of daily traffic of 50 trips is expected to be the highest volume generated during solar facility construction. Solar Facility Operational Phase Traffic Generation After the CloudBreak - Boulter Solar project has been constructed, the number of trips generated by the solar plant is expected to be significantly less than during the construction period, approximately one vehicle per week (2 weekly trips). Therefore, traffic impacts related to the operation of the solar plant facility will be negligible and insignificant. kimley-horn.com 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Kimley>>> Horn CloudBreak — Boulter Traffic Study Letter Page 3 TRIP DISTRIBUTION AND TRAFFIC ASSIGNMENT Trip distribution is based on the anticipated arrival location of employees along with the delivery route to be used for truck traffic. It is anticipated that truck traffic will utilize both US - 85 and US-34/WCR-49 for routes to the project site. Construction worker trips will be based on the arrival location from place of residence (permanent or temporary). The distribution for construction worker trips was derived based on distances to nearby cities and populations. The City of Evans is located approximately 8 miles northwest of the site, the City of Greeley is located approximately 11 miles northwest of the project site, and the Town of Kersey is located approximately nine (9) miles northeast of the site. It is believed that vehicle trips to and from Greeley will utilize both US -85 and US-34/WCR-49 routes to the project site. Further west, approximately 30 miles northwest of the site is the City of Loveland. The City of Longmont is approximately 32 miles to the southwest. Based on these factors, it is anticipated that 100 percent of the traffic will be to and from WCR-44. Attached Figure 3 illustrates the anticipated project trip distribution while the project traffic assignment volumes for construction activities is shown in attached Figure 4. CONCLUSION In summary, the CloudBreak - Boulter Solar construction project traffic assignment shows a very low traffic volume assigned to the surrounding street network. Further, trips are negligible during the operational phase of the solar facility. Based on these results, CloudBreak - Boulter Solar will have a minimal traffic impact. The public street roadways and adjacent intersections are anticipated to successfully accommodate this project traffic volume. If you have any questions or require anything further, please feel free to call. Sincerely, KIMLEY-HORN AND ASSOCIATES, INC. Tyler E. Smith, P.E. Traffic Engineer REG 1 h � •off/ L set:x-112 56897 tat • 05/03/2023 + + ogle ••-•�"# I a kimley-horn.com 1125 17th Street, Suite 1400, Denver, CO 80202 303 228 2300 Figures Kim *Horn N 0 nn-i NTS 196664000 FIGURE 1 CLOUDRREA< CULE� WELD COUNTY, COLORADO LVCHIHY MAP i RlFflIPV)flflhllll �� N O 1=1-1- N TS 196664000 [100%1 71 r 0 0 T WCR-45 ACCESS FIGURE 3 CLOUDBREAK - BOULTE� WELD COUNTY, COLORADO ` PROJECT TRIP DISTRIBUTIO N XX% LEGEND Study Area Key Intersection External Trip Distribution Percentage Entering[Exiting] XX%[XX70] Trip Distribution Percentage I _ I _ Milan a I KJIPV)))flOfl � r Kiml • 4 Horn N O FTH NTS 196664000 WCR-45 ACCESS FIGURE 4 CL0UD3EA< - B0ULE� WELD CCUNTY, CCL0AD0 PROJECT TRAFFIC ASSIGNMENT: C0NSHUCH0N ACTIVITY 1 LEGEND Study Area Key Intersection XXX(XXX) Weekday AM(PM) Peak Hour Traffic Volumes xxx Estimated Daily Traffic Volume I Ina_ 1 i IcJmIeV)))florfl � Conceptual Site Plan CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Traffic Narrative 1. Describe how many roundtrips/day are expected for each vehicle type: Passenger Cars/Pickups, Tandem Trucks, Semi-Truck/Trailer/RV (Roundtrip = One (1) trip in and One (1) trip out of site). • • • Maximum anticipated number of daily trips during peak period of construction: 10 - 15 vehicles per day during peak construction 7am - 3:30pm general hours Monday - Friday. % of heavy vehicles during peak period of construction: 5 - 10% During first few months of construction. Typical anticipated number of daily trips after construction is complete: 2 - 4 trips per year depending on O&M contract details. 2. Describe the expected travel routes or haul routes for site traffic. • The primary haul/travel route will be East on CO -34, South on County Road 49, West on County Road 44, North on County Road 45, and then arriving at the Western access point for the parcel. 3. Describe the travel distribution along the routes (e.g. 50% of traffic will come from the north, 20% from the south, 30% from the east, etc.). • 100% of the expected travel will follow the primary travel/haul route detailed above. 4. Describe the time of day that you expect the highest traffic volumes. • 7:00am - 3:30pm CLOUDBREAK CBEP SOLAR 26, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: May 15, 2024 PROJECT: Blue Spruce Solar Project SUBJECT: Utility and Other Infrastructure Owners Infrastructure Owner Name Address Oil ad Gas Pipeline DCP Operating Company, LP 370 17th Denver, St CO UNIT 80202 2500, Oil easement and Gas pipeline DCP Midstream, LP 370 17th Denver, St CO UNIT 80202 2500, Pipeline easement Panhandle Company Eastern Pipeline 8111 Dallas, Westchester TX, 75225 Dr Ste 600 Overhead Electric Lines Public Colorado DBA Service Xcel Company Energy of 1800 80202 Larimer St, Denver, CO (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM Weld County Treasurer Statement of Taxes Due Account Number R4475806 Assessed To Legal Description PT SW4 14-4-65 LOT D REC EXEMPT RE -4420 Parcel 105514300030 MICHAEL BOULTER FARMS LLC 22019 COUNTY ROAD 54 GREELEY, CO 80631-9764 Situs Address Year Tax Interest Fees Payments Balance Tax Charge 2022 $602.22 $0,00 $0.00 ($602.22) $0.00 Total Tax Charge $0.00 Grand Total Due as of 04/24/2023 $0.00 Tax Billed at 2022 Rates for Tax Area 2883 - 2883 Authority WELD COUNTY SCHOOL DIST RE 1 NORTHERN COLORADO WATER (NC CENTRAL COLORADO WATER (CCW CENTRAL COLO WATER WELL (CC LASALLE FIRE AIMS JUNIOR COLLEGE HIGH PLAINS LIBRARY WEST GREELEY CONSERVATION Taxes Billed 2022 * Credit Levy Mill Levy 15,0380000* 16.6870000* 1.0000000 1.0680000 9.0000000 5.1540000 6,3070000 3.1810000 0;4140000 Amount $156.56 $173.71 $10.41 $11.12 $93.69 $53.66 $65.65 $33.11 $431 57.8490000 $602.22 Values Actual Assessed AG -SPRINKLER $36,453 $9,620 IRRIGATED LAND AG -GRAZING LAND $2,900 $770 AG -WASTE LAND $62 $20 Total $39,415 $10,410 ALL TAX LIEN SALE AMOUNTS ARE SUBJECT TO CHANGE DUE TO ENDORSEMENT OF CURRENT TAXES BY THE LIENHOLDER OR TO ADVERTISING AND DISTRAINT WARRANT FEES. CHANGES MAY OCCUR AND THE TREASURER'S OFFICE WILL NEED TO BE CONTACTED PRIOR TO REMITTANCE AFTER THE FOLLOWING DATES: PERSONAL PROPERTY, REAL PROPERTY, AND MOBILE HOMES - AUGUST 1. TAX LIEN SALE REDEMPTION AMOUNTS MUST BE PAID BY CASH OR CASHIER'S CHECK. POSTMARKS ARE NOT ACCEPTED ON TAX LIEN SALE REDEMPTION PAYMENTS. PAYMENTS MUST BE IN OUR OFFICE AND PROCESSED BY THE LAST BUSINESS DAY OF THE MONTH. o ras--53 ti-0-13e5oso Weld County Treasurer's Office 1400 N 17th Avenue PO Box 458 Greeley, CO 80632 Phone: 970-400-3290 Pursuant to the Weld County Subdivision Ordinance, the attached Statement of Taxes Due issued by the Weld County Treasurer are evidence that as of this date, all current and prior year taxes related to this parcel have been paid in full. Date: I..k tr- �_r Hello