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Home My WebLink About20200085.tiffUSE BY SPECIAL REVIEW (USR) APPLICATION DEPARTMENT OF PLANNING SERVICES ' 1555 N. 17TH AVENUE ' GREELEY, CO 80631 www.weldgov corn ' 970-400-6100 ' FAX 970-304-6498 FOR PLANNING DEPARTMENT USE: AMOUNT $ APPLICATION RECEIVED BY DATE RECEIVED: CASE # ASSIGNED: PLANNER ASSIGNED: Parcel Number': 0 2 0 7 _ 1 0 0 0 0 0 0 4 Address of site: ('A 12 digit number on Tax I.D. information, obtainable at www vdelddov tom). Legal Description: Section: 10 Township: 11 N Range. 64 V'/ Zone District: AG Acreage: 636 Floodplein: o eological Hazard: YCN0 Airport Overlay 0® FEE OWNER(S1 OF THE PROPERTY: Name: Will Sullivan Company: Outrigger DJ Operating, LLC Phone #: 720-361-2571 Email: Street Address: 1200 Seventeenth Street, Suite 900 wsullivan@outriggerenergy.com City/Sta:e/Zip Code: Name: Trent Taylor Denver, CO 80202 Compary: Outrigger DJ Operating, LLC Phone #: 720-361-2575 Email: ttaylor@outriggerenergy.com Street Address: 1200 Seventeenth Street, Suite 900 City/State/Zip Code: Denver, CO 80202 Name: Company: Phone #: Email: Street Address- City/State/Zip Code: APPLICANT OR AUTHORIZED AGENT: (See below: Authorization must accompany all applications signed by Authorized Agents) Name: Tammy Zimbelman Company: ZAP Engineering Phone IS: 303-656-4806 Email: zimbelmant@zapecs.com Street Address: 333 S. Allison Pkwy, suite 100, Lakewood, CO 80226 City/State/Zip Code: PROPOSED USE: Gas Compressor Station I (We) -iereby depose and stale 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. Signatures of all fee owners of property must sign this application. If an Authorized Agent signs, a letter of authorization from all fee owners must be Included with the applicaton. If a corporation is the fee owner, notarized evidence must be included indicating that the signatory has to legal authority to sign (pr the corporation. Signature: Owner or Authorized Agent Date Signature: Owrer or Authorized Agent Date Will Sullivan Tammy Zimbelman Print Name Print Name Rev 4/2016 DEPARTMENT OF PLANNING AND BUILDING DEPARTMENT OF PUBLIC HEALTH AND ENVIRONNMENT 1555 NORTH 17TH AVENUE GREELEY, CO 80631 AUTHORIZATION FORM FOR BUILDING, PLANNING AND HEALTH DEPARTMENT PERMITS AND SERVICES SALT i T P9 A► I n 1 I I1 /� SAL I R'ANL,fl, LLL� 1. (We), (Owner - please print) give permission to OUTRIGGER DJ OPERATING LLC (Applicant/Agent - please print) to apply for any Planning, Building or Health Department permits or services on our behalf, for the property located at: SEC 10, T11 N, R64W aka Parcel # 020710000004 Legal Description: ALL of Section 10 , Township 11 N, Range 64 w Subdivision Name: N/A Property Owners Information: Phone: E-mail: Applicant/Agent Contact Information: Phone: 720-361-2575 Lot Block E -Mail: ttaylor@outriggerenergy.com Email correspondence to be sent to: Owner Applicant/Agent X Both Postal service correspondence to be sent to: (choose only one) Owner Applicant/Agent X Additional Info: Authorization pertains to proposed compressor site in Section 10 and all asssociated permits including but not limited to USR access, road maintenance, building, grading, etc... Owner Signature: Date: Owner Signature: Date: DEPARTMENT OF PLANNING AND BUILDING DEPARTMENT OF PUBLIC HEALTH AND ENVIRONNMENT 1555 NORTH 17TH AVENUE GREELEY, CO 80631 AUTHORIZATION FORM FOR BUILDING, PLANNING AND HEALTH DEPARTMENT PERMITS AND SERVICES I (We), Outrigger DJ Operating, LLC (Owner - please print) give permission to Tammy Zimbelman (Applicant/Agent - please print) to apply for any Planning, Building or Health Department permits or services on our behalf, for the property located at: Section bordered by CR132 unmaintained (North), CR 57 (East) CR 130 unmalntained (South), CR 55 non-existent (West) Legal Description: Whole Section of Section 10 , Township 1 N, Range 64 w Subdivision Name: UA Property Owners Information: Phone: 720-361-2571 Applicart/Agent Contact Information: Phone: 303-656-4806 Lot Block E -ma l: wsullivan@outriggerenergy.com E -Ma I: zimbelmant@zapecs.com Email ccrrespondence to be sent to: Owner ApplicantlAgent Both X Postal service correspondence to be sent to: (choose on y ore) Owner X Applicant/Agent Additional Info: Owner Signature: {' , , - - , Date: 7/419/1 rZ Owner Signature: Date: USE BY SPECIAL REVIEW (USR) QUESTIONNAIRE Outrigger DJ Operating LLC — Bayou Compressor Station Planning Questions: 1. Explain, in detail, the proposed use of the property. • This property will be used for the purpose of an unmanned 25 MMSCFD natural gas compressor station. The station will compress natural gas from nearby gathering fields to market specifications. The proposed site use includes ancillary equipment required to remotely operate the compressor station. Temporary uses associated with construction include connex containers, construction trailers, and a laydown area. This station will support existing and future development of mineral resources in the area. 2. Explain how this proposal is consistent with the intent of the Weld County Code, Chapter 22 of the Comprehensive Plan. • This proposal supports the Economic Development goals and policies outlined in Sec 22-6-20 and the agricultural private property rights covered in 22-2-10 while simultaneously complying with the goals and policies set forth regarding Natural Resources in Sec 22-5-100. • The buffer of land surrounding the plant is designed to minimize the impact of incompatibilities that occur between the natural site features and surrounding properties per Section 22-2-100 E while acceding to the County's desire to promote the safety of all citizens and structures, Section 22-5-100 B. • The County does recognize individual property owner's rights to request a land use change per Section 22-2-20 G., stating that such development should be supported and Outrigger is attempting to be compatible with the region as stated in the same Section. • Outrigger will ensure that adequate services and facilities are currently available or reasonably obtainable to accommodate the requested new land use change for more intensive development per Section 22-2-20 H. • Outrigger has and will continue to communicate with surrounding property owners per Section 22-2-20 1.5 3. Explain how this proposal is consistent with the intent of the Weld County Code, Chapter 23 (Zoning) and the zone district in which it is located • Section 23-3-40 states that agricultural land may be used, with permit, for oil and gas facilities, support and services. This site is consistent with stated intent (23-3-40 A.2). Will permit connex containers, 23 -3 -40 -BB and a telecommunication tower per section 23-3-40.K. • Section 23-2-230.B.5 - This application complies with Chapter 23, Articles V and XI, of the Weld County Code. The site is not in a floodplain, geologic hazard area or Airport Overlay District. • Section 23-2-230.6.6 — The proposed site will cover less than 10 acres, there is no irrigation water associated with this area so prime agricultural land will not be taken out of production. 4. Describe what type of land uses surround the site. Explain how the proposed use is consistent and compatible with surrounding land uses. • The areas surrounding the site have agricultural land use as well as oil and gas exploration and development. The site is designed with minimal impact and footprint to the surrounding area with plenty of buffer on all sides of the plant. The facility is designed to support the reasonable and orderly exploration and development of mineral resources occurring in the area. 5. What are the hours and days of operation? • The station will be running 24/7 as an unmanned facility with daily operator checks and remote shutdown capability if needed. 6. List the number of full-time and/or part time employees proposed to work at this site. REV 0 9/10/2019 USE BY SPECIAL REVIEW (USR) QUESTIONNAIRE Outrigger DJ Operating LLC — Bayou Compressor Station • This will be an unmanned site. No full-time/part-time employees 7. If shift work is proposed include the number of employees per shift. • N/A 8. List the number of people who will use this site. Include contractors, truck drivers, customers, volunteers, etc. • During construction there could be between 5 -25 people on site. This includes construction workers, managers, safety personnel, truck delivery drivers, inspectors • After construction, during normal operations, the site will be unmanned with one or two area operators performing daily routine checks, being on site less than two hours per day. • During a scheduled maintenance, two to ten employees/contractors/safety personnel/managers/truck drivers may be on site. 9. If this is a dairy, livestock confinement operation, kennel, etc. list the number and type of animal. • N/A 10. Describe the type of lot surface and the square footage of each type. (e.g. asphalt, gravel, landscaping, dirt, grass, buildings) • This parcel is 636 acres. The proposed compressor site is approximately 10 acres. This 10 acres will consist of: o Natural Grass: 1 acres (43,560 sq. ft.) o Gravel: 6 acres (304,920 sq. ft.) o Dirt: 1.75 acres (76,230 sq. ft.) o Buildings/skids: .25 acres (10,890 sq. ft.) o Detention Pond: TBD 11. How many parking spaces are proposed? How many handicapped (ADA) parking spaces are proposed? • This unmanned site will not have parking spaces 12. Explain the existing and proposed landscaping for the site • The existing site is natural grasses with no improvements or farming. The site is in a remote, arid region. See pictures. • The proposed site will be graveled with natural grasses remaining outside the compressor station site boundary. No additional landscaping will be implemented due to the arid nature of the area. 13. Describe the type of fence proposed for the site. • A 6 -foot chain link fence is proposed with a lockable, manual gate for access to the site. 14. Describe the proposed screening for all parking and outdoor storage areas • At this time, there is no screening plan for this site. There are no houses within a one mile radius of the site. 15. Explain any proposed reclamation procedures when termination of the Use by Special Review activity occurs. • When this site is no longer in use as a compressor station, it will be returned to its natural native grasses, the drainage pond will be emptied and back -filled. 16. Who will provide fire protection to the site? • The Pawnee volunteer fire department, 970-895-2237. They have been sent notification, see attached letter. They will be sent appropriate emergency info and access info before the site is running. (Please see attached Emergency Action Plan.) REV 0 9/10/2019 USE BY SPECIAL REVIEW (USR) QUESTIONNAIRE Outrigger DJ Operating LLC — Bayou Compressor Station 17. List all proposed on -site and off -site improvements associated with the use (e.g. landscaping, fencing, buildings, drainage, turn lanes, etc.) and a timeline of when you will have each one of the improvements completed. • Landscaping, as discussed under #12, will be gravel and dirt inside the fence and natural grasses, as common to the area, outside the fence. • The plant will be fenced with a 6' high chain link fence. There will be one manually operated, lockable gate for vehicle access. The fence will be installed after grading is complete. • The site grading will include a detention pond. The detention pond is described at length in the drainage plan. It is shown on the plot plan and designated as a "No Build/No Storage Area". • Access from County Road 57 is in the application process. The site will be accessed per Weld County code and have traction control per County requirements. County ROW will be observed. • The compressor station is unmanned and lights will normally be off unless required for operations personnel. All lights will be mounted on pipe rack or buildings where possible. Lights will be limited to critical equipment and not overly illuminate large areas. Lights will be directed downward (90 degrees to the natural ground plane). Lighting will comply with Weld County dark sky standards. • Outrigger has taken into consideration noise concerns in the planning of this site. All process equipment is a minimum of 1,000 feet from property lines. Reciprocating compressors will be in buildings and will have hospital -grade mufflers. Additionally, Outrigger has contracted Behrens and Associates, Inc. to perform a noise study for this site. The report will be included with USR documentation. • Outrigger has developed a communication plan to communicate with surrounding property owners as well as the local fire department. • Improvements will begin when appropriate permitting approval is received. Engineering Questions: 1. Describe how many roundtrips/day are expected for each vehicle type: (During normal plant operations) • Passenger cars/ pickups: 2 RT per day • Tandem trucks: 0 RT per day • Semi-trucks/trailers: 1 RT per month • RVs: 0 • PLEASE NOTE: During construction on any given day 20 - 30 RT could occur from the various vehicle types 2. Describe the expected travel routes for the site. • Access to the site will occur while traveling north on CR 57 from CR 128. Vehicles leaving the site will travel south on CR 57 to CR 128. 3. Describe the travel distribution along the routes. • 100% of the traffic will come from CR 128 and head north on CR 57 to the entrance of the site. See attached map. 4. Describe the time of day that you expect the highest traffic volume from above. • 6:30 a.m. - 6:30 p.m. 5. Describe where the access to the site is planned. REV 0 9/10/2019 USE BY SPECIAL REVIEW (USR) QUESTIONNAIRE Outrigger DJ Operating LLC — Bayou Compressor Station • One access road is planned on the east side of the property off of CR 57, approximately 2,500' north of CR 130. 6. Drainage Design: Detention pond summarized in a drainage report is required unless the project falls under an exception to storm water detention requirements per code section 23-12-30 F 1. • A.) Does your site qualify for an exception to storm water detention? NO • B.) Does your site require a storm water detention pond? YES, a drainage report will be provided according to Weld County standards. Environmental Health Questions: 1. What is the drinking water source on the property? • The bottled drinking water will be provided during construction. • This will be an unmanned site therefore no well water or municipal water will be provided. 2. What type of sewage disposal system is on the property? • There is no sewage disposal on site. Port -a toilets will be provided per OSHA standards during construction. • This will be an unmanned site therefore no sewage system will be installed. 3. If storage or warehousing is proposed, what type of items will be stored? • Temporary storage of slop water to be trucked off site for disposal 4. Describe where and how storage and/or stockpile of wastes, chemicals, and/or petroleum will occur on this site. • As stated above and reference site plot plan for location of storage tanks. 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. • There will be no fuel storage on site. 6. If there will be washing of vehicles or equipment on site indicate how the wash water will be contained. • No vehicle washing is planned for this site. 7. If there will be floor drains indicate how the fluids will be contained. • Floor drains in the compressor buildings will be routed to a containment that will be evacuated as needed and trucked off site to approved disposal location. 8. Indicate if there will be any air emissions. (e.g. painting, oil storage, etc.) • The air permit application process is currently in progress with the State. 9. Provide a design and operations plan if applicable (e.g. composting, landfills, etc.) • N/A 10. Provide a nuisance management plan if applicable (e.g. dairies, feedlots, etc.) • N/A 11. Additional information may be requested depending on type of land use requested. Building Questions: 1. List the type, size (square footage), and number of existing and proposed structures. • Existing Structures — NONE REV 0 9/10/2019 USE BY SPECIAL REVIEW (USR) QUESTIONNAIRE Outrigger DJ Operating LLC — Bayou Compressor Station • Proposed Structures: o One (1) 8' x 12' Compressor Station Control Building o Four (4) 20' x 45' Compressor Enclosures: arctic pack, CO Res 35, hospital grade mufflers o Two (2) 4' x 6' Meter Skid Housings o One (1) 8' x 15' Instrument Air skid Enclosure • Reference provided site plot plan 2. Explain how the existing structures will be used for this USR? • N/A 3. List the proposed use(s) of each structure. • The Compressor Control Building will be used to house the electrical equipment, computers, etc. to run the site and relay info to main control center • The Compressor Enclosures will each house one compressor in order to protect it from the elements • The meter houses are to protect sensitive metering/monitoring equipment • The Instrument Air skid enclosure houses the instrument air compressor. Air is used to operate various instruments on site See provided maps to locate structures, parking, public roads, access points, and property boundary. REV 0 9/10/2019 FOR COMMERCIAL SITES, PLEASE COMPLETE THE FOLLOWING INFORMATION BUSINESS EMERGENCY INFORMATION: Business Name: Bayou Compressor Station Address: Section 10, T11 N, R64W Business Owner: Outrigger DJ Operating, LLC Phone: City, ST, Zip: [-16 miles west of Hereford 80729] Home Address: 1200 17th Street, Suite 900 Phone: 720-368-7312 City, ST, Zip: Denver, CO 80202 List three persons in the order to be called in the event of an emergency: NAME TITLE Andrew Perdue Sr Project Manager ADDRESS PHONE 1200 17th Street, Suite 900 720-361-2580 Trent Taylor Manager of Land Development 1200 17th Street, Suite 900 720-361-2575 Will Sullivan Engineering & Operations 1200 17th Street, Suite 900 720-361-2571 Business Hours: under construction Days: Monday - Saturday Type of Alarm: ✓ None In Burglar Holdup Fire Silent IN Audible Name and address of Alarm Company: Location of Safe: NSA MISCELLANEOUS INFORMATION: Number of entry/exit doors in this building: NSA Location(s): Is alcohol stored in building? N/A Location(s): Are drugs stored in building? N/A Location(s): Are weapons stored in building? N/A Location(s): The following programs are offereils a public service of the Weld Count heriffs Office. Please indicate the programs of interest. Physical Security Check Crime Prevention Presentation UTILITY SHUT OFF LOCATIONS: Main Electrical: None currently Gas Shut Off: None currently Exterior Water Shutoff: None currently Interior Water Shutoff: None currently • ^ti ;4 __', '164_ 1 L FINAL DRAINAGE REPORT BAYOU COMPRESSOR STATION (USR19-0062) Located in: SECTION 10, TOWNSHIP 11 NORTH, RANGE 64 WEST OF THE 6T{( PRINCIPAL MERIDIAN, WELD COUNTY, CO Prepared: September 30, 2019 Revised: November 12, 2019 Prepared for: Outrigger DJ Operating LLC 1200 Seventeenth St., Suite 900, Denver, CO 80202 Prepared By: Crestone Consultants, LLC 14145 West Warren Cir. Lakewood, CO 80228 303.997.6113 Crestone Project No. 19021 CRESTONE CONSULTANTS, LLC civil engineering solutions Weld County Drainage Code Certificate of Compliance Weld County Case Number: USR19-0062 Parcel Number: 020710000004 Legal Description, Section/Township/Range: Section 10, T-11 North. R-64 West of the 6th P M. Date: November 12. 2019 Joseph M. Erjavec, P.E. Consultant Engineer for Outrigger DJ Operating LLC (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 variance(s) described on •,-- _ . • -d exhibits. This certification is not a guarantee or warranty either expressed or implied. REGib .a �(%37fl4 fMnit O• `' 1 Engineer's Stamp For and on behalf of JME Design Group, LLC dba Crestone Consultants. LLC ngineer of Record Signature 1. 2. 3. Describe List the Describe Demonstrate that there result design of the the hardshi the proposed that are project. criteria granting no adverse -••....•••' Variance Request 'If Applicable) requested. the intent health, -of -way safety, and/or of the Weld and general offsite County welfare properties Code. and as a the variance is being County Code of which with engineering rationale variance will still adequately from stormwater runoff requested. a variance which protect to the is being supports public public rights of the Weld alternative of the impacts Public Works Director/Designee Review (If Applicable) Public Works Director/Designee Name Date of Signature Comments: Signature Approved i] Denied Department of Public Works I Development Review 1111 H Street, Greeley, CO 80631 ( Ph: 970-304-6496 I www.weldgov.com/departments/public_works/development_review 08/02/2019 r BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 TABLE OF CONTENTS Page I - INTRODUCTION 1 II — GENERAL LOCATION & DESCRIPTION 1 Location 1 Description of Property 1 III - DRAINAGE BASINS AND SUB -BASINS 3 Major Basin Description 3 Historic Sub -Basin Description 4 Developed Basin Descriptions 4 IV — DRAINAGE DESIGN CRITERIA 5 Development Criteria Reference and Constraints 6 Hydrological Criteria 6 Hydraulic Criteria 8 V — DRAINAGE FACILITY DESIGN 11 General Concept 11 Specific Details 12 VII - CONCLUSIONS 14 VIII - REFERENCES 15 Crestone Project No. 19021 Page I i BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 LIST OF APPENDICES APPENDIX A — General Information Vicinity Map NRCS Soils Data FEMA Flood Insurance Rate Map APPENDIX B — Hydrologic Calculations (Historic & Developed Condition) Rational Method Calculations Hec-22 SCS (NRCS) Method Calculations Hydrologic Calculation Reference Materials APPENDIX C — Hydraulic Calculations (Developed Condition) Channel Sizing Calculations Culvert Sizing Calculations Riprap Sizing Calculations Detention Pond Sizing Calculations Hydraulic Calculation Reference Materials APPENDIX D — Maps Historic Condition Drainage Exhibit Developed Condition Drainage Exhibit Drainage Details APPENDIX E — Construction Plans (Attached Under Separate Cover) Crestone Project No. 19021 Page I ii BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 I - INTRODUCTION This Final Drainage Report has been prepared for the Bayou Compressor Station and will outline the methodology for sizing of stormwater conveyances and attenuation facilities associated with the proposed Compressor Station project. The operator of the facility, Outrigger DJ Operating LLC, is proposing to construct a Compressor Station on approximately 10 acres which includes various equipment, buildings and an access road. The proposed facility will also include a Detention Pond for stormwater attenuation & water quality enhancement. II - GENERAL LOCATION & DESCRIPTION Location A) The USR Parcel is Section 10, Township 11 North, Range 64 West of the 6t Principal Meridian, which is approximately 38 miles north/northeast of Greeley, Colorado and approximately 4.5 miles south of the Wyoming state line. The Bayou Compressor Station is located in the Northeast Quarter of Section 10. See Appendix A for a Vicinity Map. B) The proposed Compressor Station site is located approximately 1,700 feet west of County Road 57 and approximately 2,900 feet north of County Road 130. C) Geary Creek is located within the USR Parcel. The proposed Compressor Station pad is located within Zone D — Area of Undetermined Flood Hazard per the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (Map #08123C0375E, dated January 20, 2016). Description of Property A) The area associated with the USR Parcel is approximately 636 acres. The majority of the existing parcel consists of undeveloped pasture, with an existing well pad site located in the northeast corner of the USR Parcel that includes a gravel pad. Geary Creek meanders generally from northwest to southeast and bisects the USR parcel. The USR Parcel is bound by County Road 57 (gravel) on the east, an unimproved road (County Road 132 - gravel) along the northern boundary and an unimproved road (County Road 130 — gravel) along the southern boundary. B) As per the National Resources Conservation Service (NRCS), the predominant soils within the Bayou Compressor Station vicinity are described as follows: 4 - Ascalon fine sandy loam, 0 to 6 percent slopes Parent material: Wind -reworked alluvium and/or calcareous sandy eolian deposits, slope ranging from 0 to 6%, have moderately high to high water capacity, are well drained, have a depth to water table greater than 80 inches, have a low to moderate susceptibility to erosion from water, and have a high susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group B (moderate infiltration rate; moderate runoff potential). Crestone Project No. 19021 Page I 1 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 27 — Epping silt loam, 0 to 9 percent slopes Parent material: Calcareous loamy residuum weathered from siltstone, slope ranging from 0 to 9%, have a moderately low to moderately high water capacity, are well drained, have a depth to water table greater than 80 inches, have a high susceptibility to erosion from water, and have a moderate susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group D (very slow infiltration rate; high runoff potential). 29 — Haverson loam, 0 to 3 percent slopes Parent material: Stratified, calcareous loamy alluvium, slope ranging from 0 to 3%, have a moderately high to high water capacity, are well drained, have a depth to water table greater than 80 inches, have a moderate susceptibility to erosion from water, and have a moderate susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group B (moderate infiltration rate; moderate runoff potential). 31 — Kim -Mitchell complex, 0 to 6 percent slopes Parent material: Calcareous loamy alluvium, slope ranging from 0 to 6%, have a moderately high to high water capacity, are well drained, have a depth to water table greater than 80 inches, have a moderate susceptibility to erosion from water, and have a moderate susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group C (slow infiltration rate; moderate runoff potential). 32 — Kim —Mitchell complex, 6 to 9 percent slopes Parent material: Calcareous loamy alluvium and/or colluvium, slope ranging from 6 to 9%, have a moderately high water capacity, are well drained, have a depth to water table greater than 80 inches, have a moderate susceptibility to erosion from water, and have a moderate susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group C (slow infiltration rate; moderate runoff potential). 34 — Manter sandy loam, 0 to 6 percent slopes Parent material: Calcareous loamy alluvium, slope ranging from 0 to 6%, have a high water capacity, are well drained, have a depth to water table greater than 80 inches, have a moderate susceptibility to erosion from water, and have a high susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group A (high infiltration rate; low runoff potential). 54 — Platner loam, 0 to 3 percent slopes Parent material: Mixed eolian deposits over tertiary aged alluvium derived from igneous, metamorphic and sedimentary rock, slope ranging from 0 to 3%, moderately low to moderately high water capacity, are well drained, have a depth to water table greater than 80 inches, have a moderate susceptibility to erosion from water, and have a low susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group C (slow infiltration rate; moderate runoff potential). 61 — Stoneham fine sandy loam, 0 to 6 percent slopes Parent material: Calcareous loamy alluvium, slope ranging from 0 to 6%, moderately high to high water capacity, are well drained, have a depth to water table greater than 80 inches, Crestone Project No. 19021 Page 12 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 have a moderate susceptibility to erosion from water, and have a high susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group B (moderate infiltration rate; moderate runoff potential). 74 — Vona sandy loam, 3 to 9 percent slopes Parent material: Calcareous sandy alluvium and/or eolian deposits, slope ranging from 3 to 9%, high water capacity, are well drained, have a depth to water table greater than 80 inches, have a moderate susceptibility to erosion from water, and have a high susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group A (high infiltration rate; low runoff potential). 75 — Wages fine sandy loam, 0 to 6 percent slopes Parent material: Calcareous loamy alluvium, slope ranging from 0 to 6%, moderately high to high water capacity, are well drained, have a depth to water table greater than 80 inches, have a low to moderate susceptibility to erosion from water, and have a high susceptibility to wind erosion. The NRCS Hydrologic Soil Group for this type of soil has been classified as Group B (moderate infiltration rate; moderate runoff potential). Please refer to Appendix A for NRCS soils data. C) Geary Creek is located within the USR parcel but a floodplain has not been identified. D) The project involves constructing a Compressor Station on approximately 10 acres which includes various equipment, buildings and an access road. The proposed facility will also include a Detention Pond for stormwater attenuation & water quality enhancement. E) The Project Site does not include irrigation facilities. F) The Project Site is NOT located within the Weld County MS4 area. III - DRAINAGE BASINS AND SUB -BASINS Major Basin Description The USR parcel is within the South Platte River watershed and contains a drainageway — Geary Creek, which outfalls into Little Crow Creek (outfall located within Section 16, Township 9 North, Range 62 West). Little Crow Creek runs southeast and outfalls into Crow Creek (outfall located within Section 34, Township 9 North, Range 62 West). Crow Creek runs south/southwest and outfalls into the South Platte River (outfall located in Section 24, Township 5 North, Range 64 West). The Project Site is located within Zone D — Area of Undetermined Flood Hazard per the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (Map #08123C0375E, dated January 20, 2016). Crestone Project No. 19021 Page 13 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 Historic Sub -Basin Description A) The Project Site includes one historic sub -basin as well as three offsite basins which are tributary to the proposed Compressor Station and associated access road. The historic basin and offsite basins are described as follows: Basin H1 8.98 ac/2.0% Imp) Basin H1 is comprised of the proposed Compressor Station and the westernmost portion of the proposed access road from County Road 57. Runoff generated by this basin sheet flows south/southwesterly and exits the Project Site at Design Point i, on the southern end of the basin. Runoff combines with runoff from Basins O51 & OS2 within the proposed Compressor Station parcel and continues south/southwesterly before outfalling into Geary Creek approximately 1,100 ft south of the Compressor Station site. Basin OS1 (22.46 ac/2.5% Imp) Basin OS1 is located west and north of the proposed Compressor Station. Runoff generated by this basin flows southwesterly/south/southeasterly and enters the Project Site near the southwest corner of the parcel at Design Point 2. Runoff combines with runoff from Basins Hi & 0S2 within the proposed Compressor Station and continues south/southwesterly before outfalling into Geary Creek approximately 1,100 ft south of the Compressor Station. Basin OS2 '9.19 ac/3.0% Imp, Basin OS2 is located north of the proposed Compressor Station, between Basins OS1 & O53. Runoff generated within this basin generally flows south and enters the Project Site near the northwest corner of the Compressor Station at Design Point 3. Runoff combines with runoff from Basins Hi & O51 within the proposed Compressor Station parcel and continues south/southwesterly before outfalling into Geary Creek approximately 1,100 ft south of the proposed parcel. Basin O53 (250.51 ac/3.2% Imp Basin OS3 is located north and east of the proposed Compressor Station and includes the existing well pad site in the northeast corner of the USR Parcel. This basin (which was delineated from USGS data) extends approximately 1.3 miles north of the USR Parcel. Although it is likely that a portion of the runoff generated within this basin crosses County Road 57 to the east (particularly at the County Road 57 and County Road 132 intersection), it is assumed that all of the runoff flows south along the west side of County Road 57 and enters the USR Parcel where it continues to flow to the south and is tributary to the proposed Compressor Station's access road (Design Point 4). Beyond the proposed access road, runoff continues to generally flow south and outfalls into Geary Creek near the southeast corner of the USR Parcel. Please refer to Appendix D for a copy of the Historic Condition Drainage Exhibit. Developed Basin Descriptions In the developed condition, the Compressor Station is comprised of one basin (Basin D1) which includes a proposed Detention Pond. As previously discussed, offsite areas (Basins OS1, OS2 and OS3) are tributary to the Project Site and associated access road. Crestone Project No. 19021 Page 14 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 The developed basins as well as measures employed to route the tributary offsite runoff are described as follows: Basin D1 (8.98 ac/50.0% Imp) Basin D1 is comprised of the proposed Compressor Station, associated proposed Detention Pond and the westernmost portion of the proposed access road from County Road 57. Runoff generated within the basin sheet flows south/southwesterly into the proposed Detention Pond (Design Point 1). Attenuated flows are released to the south and follow the historic flow path to Geary Creek (approximately 1,100 feet south of the Project Site). Routing of flows that originate in the three offsite basins which are tributary to the Compressor Station and/or access road are described as follows: A berm which surrounds Basin Dl along with minor swales are proposed to direct offsite flows from Basins OS1 & OS2 west and south around the Compressor Station. Near the southwest corner of the Compressor Station, the combined runoff will flow southeasterly and combine with the attenuated flows from the Basin D1 Detention Pond and continue south/southwesterly within the historic flow path before outfalling into Geary Creek, approximately 1,100 feet south of the Project Site. Basin O52 runoff will be routed to the west via a proposed berm and minor swale along the north side of the Compressor Station. The re -directed runoff will combine with runoff from Basin OS1 near the northwest corner of the Project Site. From here, the combined runoff from Basins O51 & OS2 will be directed south around the western side of the Compressor Station. Near the southwest corner of the Compressor Station, the combined runoff will flow southeasterly and combine with the attenuated flows from the Basin D1 Detention Pond and continue south/southwesterly within the historic flow path before outfalling into Geary Creek, approximately 1,100 feet south of the Project Site. Basin OS3 has been delineated because runoff generated within this basin is tributary to the Compressor Station's access road, which is located east of the Compressor Station and connects to County Road 57. Since the access road will impede the runoff's natural flow paths, two culverts are proposed which will convey the 10 year flow to the south side of the access road. The runoff will continue to flow generally south and outfall into Geary Creek near the southeast corner of the USR Parcel. For storms larger than the 10 year event, runoff will flow through the proposed culverts and overtop the proposed access road and flow generally south to Geary Creek. Please refer to Appendix D for a copy of the Developed Condition Drainage Exhibit and Appendix C for the culvert and associated weir sizing calculations for the proposed access road. IV - DRAINAGE DESIGN CRITERIA The regulations, guidelines and drainage design criteria used in the preparation of this Report are those contained within the Weld County Code Ordinance 2019-12, Chapter 8 — Public Works, Article XI — Storm Drainage Criteria and the Urban Drainage and Flood Control District (UDFCD), Urban Storm Drainage Criteria Manual — Volumes 1, 2 and 3. Crestone Project No. 19021 Page I S BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 Development Criteria Reference and Constraints A) Existing Drainage Studies - The Project Site is not known to be included in any previous drainage studies. B) The siting of the proposed Compressor Station within the USR Parcel was influenced by the location of the existing oil & gas facilities (i.e. well pad in the northeast corner of the parcel) as well as the location of Geary Creek which flows from northwest to southeast through the USR parcel. Hydrological Criteria A) The 1 hour rainfall depths listed below were obtained from the National Oceanic and Atmospheric Administration (NOAA) Precipitation Frequency Data Server for the Project Site, and were utilized in determining the historic, existing and developed hydrologic calculations, as well as in calculating the required 100 year volume (Modified FAA Method) for the proposed Detention Pond. 2 Year 5 Year 10 Year 100 Year 0.89 in 1.17 in 1.42 in 2.45 in The design storms analyzed in this Report are as follows: Minor Storm — 10 year, 1 hour storm occurrence is utilized for sizing culverts, riprap and determining the historic releases which are used in the Modified FAA Method detention pond sizing calculations. Please Note — The USR Parcel is located in a NON -URBANIZING AREA. Major Storm — 100 year, 1 hour storm occurrence is utilized for open channel and FAA Method detention pond sizing calculations. B) The Rational Method was used to determine the historic & developed flowrates for the 5, 10 & 100 year storms for basins less than 160 acres in size (i.e. Basins D1, H1, OS1 & OS2). Please Note — the Rational Method formula utilized in this Report is based on the January 2007 version of the UDFCD, Urban Storm Drainage Criteria Manual — Volume 1. This version of the Urban Storm Drainage Criteria Manual was provided by Weld County for use in preparing this Report. C) The Hec-22 SCS (NRCS) method for computing the unit hydrographs was utilized to determine historic flowrates for Basin OS3 since the basin is larger than 160 acres. AutoCAD Hydraflow Hydrographs Extension software has been utilized as the means of conducting the Hec-22 SCS/TR-55 analysis modeling. The Time of Concentration utilized in the Hec-22 SCS method has been computed using the TR- 55 method. The TR-55 method sums sheet flow time, plus shallow concentrated flow time, plus Crestone Project No. 19021 Page 16 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 channel flow time to determine the basin time of concentration which is applied in the Hec-22 SCS method peak flow unit hydrograph. Design storm data utilized includes the SCS, Type II, 24 -Hour Distribution. The SCS 24 -Hour Distribution data listed below was utilized in the hydrologic calculations and obtained from the National Oceanic and Atmospheric Administration (NOAH) Precipitation Frequency Data Server for the Project Site. 2 Year/24-Hr 5 Year/24-Hr 10 Year/24-Hr 100 Year/24-Hr 1.74 in 2.18 in 2.58 in 4.19 in Runoff Curve Numbers (Cn) which were refined by NRCS hydrologic soils groups were applied and utilized in the Hec-22 SCS/TR-55 hydrologic calculations. Cn's utilized include: Cn Description Cn per NRCS Soils Group A B C D "Runoff Curve Numbers for Agricultural Lands; Cover Type — Pasture, grassland or range — continuous forage for grazing - Fair" 49 69 79 84 "Fully Developed Urban Description — Gravel (including Areas; Cover right-of-way)" 76 85 89 91 D) The following table summarizes the historic, existing and developed Rational Method flowrates (Basins H1, O51, O52 & D1) and the existing Hec-22 SCS/TR-55 flowrates (Basin OS3): Basin Area (ac) Q5 (cfs) O10 (cfs) O100 (cfs) H1 8.98 1.0 2.9 11.4 OS1 22.46 2.1 4.7 16.9 O52 9.19 1.2 2.7 9.5 Sum 051-052 31.65 3.0 6.7 23.9 OS3 250.51 13.5 25.3 100.0 D1 8.98 7.8 10.9 24.4 E) UDFCD equations were utilized to determine required Water Quality Capture Volume (WQCV) for the proposed Detention Pond. F) The Modified FAA Method has been utilized in determining the 100 year required volume for the proposed Detention Pond. Refer to Appendix B for Hydrologic Calculations and Reference Materials. Crestone Project No. 19021 Page 17 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 Hydraulic Criteria A) Analysis Methodology & Capacity References 1. Channels Channel analysis presented in this Report has utilized the Manning's equation to compute flowrates at varying depths of flow. Design parameters used for the grass lined channels include: Native Grass Lined Channels • Manning's n = 0.032 (maintained channel condition) for velocity analysis • Manning's n = 0.05 (unmaintained channel condition) for capacity analysis • Maximum Velocity = 5.0 fps Gravel Lined Channels • Manning's n = 0.035 (maintained channel condition) for velocity analysis • Manning's n = 0.07 (unmaintained channel condition) for capacity analysis • Maximum Velocity = 16.0 fps Concrete Lined Channels • Manning's n = 0.011 for velocity analysis • Manning's n = 0.013 for capacity analysis • Maximum Velocity = 18.0 fps The following table summarizes the sizing of the Channels: Channel Type Depth (ft) (1) Design Q100 (cfs) (2) Max. Water Depth (ft) (3) Max. Velocity (fps) Freeboard (ft) CH1 Gravel 1.8 9.4 0.8 2.32 1.0 (3; Design flow is based on the ratio of area that is tributary to CH1 from Basin D1 (38% of Basin D1 is tributary to CH1, therefore 38% of 24.4 cfs is 9.4 cfs) Based on design channel with the minimum channel slope & unmaintained Manning's n. Based on design channel with the maximum channel slope & maintained Manning's n. 2. Culvert Culvert analysis presented in this Report has utilized the Orifice Equation (inlet control) and the Energy Equation (outlet control) to compute the hydraulic analysis for culverts. Two access road culverts have been designed to together convey the existing 10 year flow for Basin O53. Design parameters used for sizing the culverts are as follows: • Reinforced Concrete Pipe or Plastic Pipe material / Corrugated Metal Pipe material • Manning's n = 0.013 / 0.025 • Maximum outlet velocity = 12.0 fps / 12.0 fps • Maximum Hw/D of 2.0 (for less than 36" diameter) Crestone Project No. 19021 Page 18 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 The following table summarizes the sizing of the Culverts: Culvert Dia./Type (1) Design Q10 (cfs) Headwater Depth (ft) Outlet Velocity (fps) Hw/D Slope STM1 24" CMP 12.7 2.71 4.61 1.36 0.5% STM2 24" CMP 12.7 2.51 4.61 1.25 0.7% Design flow is based on the ratio of area that is tributary to STM1 & STM 2 from Basin OS3 (50% of Basin O53 is tributary to STM1 & STM 2, therefore 50% of 25.3 cfs is 12.7 cfs for STM1 & STM2) B) Modeling Software AutoCAD Hydraflow Express Extension software has been utilized as the means of conducting the hydraulic analysis modeling for the proposed channels and culverts presented in this Report. C) The Detention Pond has been sized for the proposed improvements and is based on the entire area that is tributary to the pond. Detention Pond D1 is within Basin D1 and is located at the southwest corner of the Project Site. The Modified FAA Method was utilized to size the Detention Pond based on the following criteria: • Store the stormwater runoff generated by the 1 hour, 100 year storm falling on the developed site and release of the detained water at the historic runoff rate of the 1 hour, 10 year storm falling on the undeveloped site with a 2% imperviousness (the USR parcel is located in a NON -URBANIZING area). • WQCV is being provided as part of the required 100 year detention volume. The following table summarizes the sizing and volume requirements of the Detention Pond: Basin Area (ac) Req'd WQCV Volume (ac -ft) Req'd 100 Year Detention Volume via Modified FAA Method (ac -ft) D1 8.98 0.19 0.90 1. The runoff volume stored in the proposed Detention Pond will be released at or below historic discharge rates (which are defined as the 10 year, 1 hour storm, since the Project Site is located within a NON -URBANIZING AREA). The Detention Pond outlet structure will control the release from the pond. The outlet structure consists of a modified CDOT Type C inlet which includes a 2 -stage release and a trash rack. The initial release includes a WQ Plate which has been sized to release the WQCV over a 40 hour duration. The WQ Plate includes 1 column of 3 rows of 1" tall x 2-5/16" wide openings. The second release includes a Restrictor Plate which covers the outlet structure's 12" outfall pipe. This release reduces the 100 year release from the pond to the historic (10 year, 1 hour) release rate of 2.9 cfs. Crestone Project No. 19021 Page 19 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 Based on the proposed release rate of 2.9 cfs for the 100 year storm and the 40 hour drain time for the WQCV, a 100 year storm event for Detention Pond D1 has been calculated to drain in approximately 46 hours. This meets the CDWR's Administrative Statement Regarding the Management of Storm Water Detention Facilities and Post- Wildland Fire Facilities in Colorado, dated February 11, 2016, which states a stormwater detention facility: • "Has the ability to continuously release or infiltrate at least 97 percent of all of the water from a rainfall event that is equal to or less than a five-year storm within 72 hours of the end of the rainfall event." • "Has the ability to continuously release or infiltrate at least 99 percent of all of the water from a rainfall event that is greater than a five-year storm within 120 hours of the end of the rainfall event." 2. A 12" outfall pipe will convey the pond release from the outlet structure to existing ground, through a low tailwater stilling basin south of the Detention Pond. 3. An emergency overflow has been designed as part of the Detention Pond. The emergency overflow has been sized to convey the 100 year developed in -flow rate into the pond (24.4 cfs) at a total depth of less than or equal to 0.5 ft. The emergency overflow crest length is 26 ft and includes a concrete cutoff wall and buried riprap on the downstream side of the spillway. 4. The pond includes 1.87 ft of freeboard above the required 100 year volume - water surface elevation to the top of the pond. The pond includes 1.0 ft of freeboard from the emergency overflow crest to the top of the pond berm 5. The Detention Pond will be located within the fenced area to protect animals and humans from accessing the pond area. A summary of the Detention Pond includes: Pond Invert: 5412.00 Top of Pond (Berm): 5416.00 WQCV: 0.19 ac -ft WQCV W.S. Elev: 5413.11 WQCV Release Rate: 40 hours Required/Provided 100 Year Pond Volume: 0.9 ac -ft 100 Year W.S. Elev.: 5414.13 100 Year Release Rate: 2.9 cfs (based on historic 10 year, 1 hour) Emergency Overflow Crest Elev: 5415.00 Provided Freeboard: 1.87 ft Crestone Project No. 19021 Page 110 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 D) Permanent erosion control features consist of the proposed Detention Pond, native vegetation adjacent to the access road and channel stabilization via gravel. Additionally, riprap erosion protection will be utilized for culvert outfalls, concentrated flow points, etc. Refer to Appendix C for all Hydraulic Calculations (i.e. Channel, Culvert, Riprap & Detention Pond sizing) and Reference Materials. V - DRAINAGE FACILITY DESIGN General Concept A) The storm drainage conveyance and storage elements have been designed to safely collect and convey developed condition runoff generated by the 100 year, 1 hour storm event within the proposed Compressor Station. The developed runoff will be routed to a proposed Detention Pond which has been designed to include the WQCV and attenuation of the 100 year storm event. B) Tributary offsite flows will be routed around the proposed Compressor Station via proposed berms with minor swales. Therefore, "run-on" from outside of the proposed Compressor Station will not be conveyed to Detention Pond Dl. Regarding offsite releases, all developed runoff from proposed Project Site will be routed through the proposed Detention Pond and released at less than historic rates. The release from Detention Pond D1 will be conveyed south/southwesterly via surface runoff and outfall into Geary Creek approximately 1,100 feet south/southwest of the Project Site, consistent with historic and existing drainage conveyance and outfall patterns. C) Multiple tables, figures and drawings have been included within the appendices of this Report and include the following: APPENDIX A — General Information Vicinity Map NRCS Soils Data FEMA Flood Insurance Rate Map APPENDIX B — Hydrologic Calculations (Historic & Developed Condition) Rational Method Calculations Hec-22 SCS (NRCS) Method Calculations Hydrologic Calculation Reference Materials APPENDIX C — Hydraulic Calculations (Developed Condition) Channel Sizing Calculations Culvert Sizing Calculations Riprap Sizing Calculations Detention Pond Sizing Calculations Hydraulic Calculation Reference Materials Crestone Project No. 19021 Page 111 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 APPENDIX D — Maps Historic Condition Drainage Exhibit Developed Condition Drainage Exhibit Drainage Details APPENDIX E — Construction Plans (Attached Under Separate Cover) D) In addition to the Detention Pond and its associated features, hydraulic structures associated with the proposed Compressor Station include a drainage channel and culverts. There is one proposed drainage channel. Channel CH1 is an irregular gravel lined channel with a 5 ft wide bottom, 4:1 maximum side slopes and a depth of 1.8 ft. CH1 carries developed flows from a portion of Basin D1 west into the proposed Detention Pond. There are two culverts proposed for the Compressor Station access road (STM1 & STM2). Both culverts are 24" in diameter and are designed to together convey the 10 year existing runoff generated by offsite Basin O53. For storms larger than the 10 year event, runoff will flow through the proposed culverts and overtop the proposed access road and flow south/southeasterly to Geary Creek. See Appendix C for culvert sizing and access road weir sizing calculations. Specific Details A) See the specific details identified for Detention Pond D1 under Section IV (Drainage Design Criteria) of this Report. B) Maintenance Plan All stormwater facilities designed herein are privately owned & maintained. The property owner and/or operator will be responsible for regular maintenance and repairs of the drainage facilities which include drainage channels, culverts, riprap, the detention pond and its associated features. Drainage channels, culverts and the detention pond shall be inspected routinely on at least a quarterly basis and after significant storm events. Routine maintenance activities for the channels, culverts and detention pond (including pond outlet structure, emergency overflow and maintenance access) include mowing/weed control, trash & debris removal, erosion mitigation through re -gravelling, replanting/watering, overgrown vegetation removal and structural repair. Crestone Project No. 19021 Page 12 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 The following table provides routine maintenance guidelines: Summary of Routine Maintenance Activities Maintenance Activity Minimum Frequency Look for: Maintenance Action Trash/Debris Removal Monthly Trash & debris in channel and pond Remove and dispose of trash and debris Mowing Twice annually for native species Excessive grass height/aesthetics Mow native grass to a height of 6" Inflow Point/Trash Rack/Outlet Works Cleaning As needed; after significant storm events; w/ other maintenance Clogged inflow points, channel culverts, pond release; ponding water Remove and dispose of debris/trash/sediment to allow proper function Weed Control As needed, based upon inspections Noxious weeds; Unwanted vegetation Treat w/ herbicide or hand pull; Consult the local weed inspector Vegetation Removal/Tree Thinning As needed, based upon inspections Trees and plant vegetation around channel features/ bottom, inflow points, pond release, emergency overflow Remove vegetation with tree trimming tools; Consult with arborist concerning evasive species; restore grade and surface Rodent Damage As needed, based upon inspections Holes, small piles of dirt, raised burrows Evaluate damage; consult animal control specialist or DOW for guidance Mosquito Treatment As needed Standing water/mosquito habitat Treat w/ EPA approved chemicals Based on the routine inspections, provide periodic minor and major maintenance activities for the channels, culverts and pond (including outlet structure, emergency overflow and maintenance access) include sediment removal from the channels, riprap pads, pond bottom, pond outlet structure; erosion repair; overgrown vegetation removal; structural repair/ replacement. The following table provides minor maintenance guidelines: Summary of Minor Maintenance Activities Maintenance Activity Minimum Frequency Look for: Maintenance Action Sediment Removal As needed, based upon inspections Sediment build-up Remove and dispose of sediment Erosion Repair As needed, based upon inspections Rills/gullies forming in channel bottom, on side slopes, pond Repair eroded areas Re -vegetate; address source of erosion Crestone Project No. 19021 Page 113 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 Maintenance Activity Minimum Frequency Look for: Maintenance Action Vegetation Removal/Tree Thinning As needed, based upon inspections Large trees/wood vegetation around channel features and channel bottom Remove vegetation with tree trimming tools; Consult with arborist concerning evasive species; restore grade and surface Drain Cleaning/ Jet Vac As needed, based upon inspections Sediment build-up at inflow points, channel culverts, energy dissipaters Clean culverts, drains, energy dissipaters, and stilling basins; Jet Vac if needed Re -vegetation As needed, based upon inspections Bare areas Repair by localized seeding or sodding The following table provides major maintenance guidelines: Summary of Major Maintenance Activities Maintenance Activity Minimum Frequency Look for: Maintenance Action Major Sediment Removal As needed, based upon inspections Large quantities of sediment; reduced conveyance capacity Remove and lawfully dispose of sediment. Repair vegetation as needed Major Erosion Repair As needed, based upon inspections Severe erosion including gullies, excessive soil, displacement, settlement, holes Repair erosion, re -vegetate and stabilize — find cause of problem and address to avoid future erosion Structural Repair As needed, based upon inspections Deterioration and/or damage to structural components — broken concrete, damaged pipes Structural repair to restore the structure to its original design VII - CONCLUSIONS A) Compliance with Weld County Code This Final Drainage Report has been prepared in accordance with Weld County Code. Historic, existing and developed runoff rates have been calculated based on the criteria, methods and information coordinated and received from Weld County. Hydraulic infrastructure, including a proposed Detention Pond has been sized in accordance Weld County requirements. B) Drainage Concept Developed runoff generated from proposed Compressor Station is conveyed via overland flow into a proposed Detention Pond and released via the 2 -stage outlet structure at attenuated release rates (40 hour duration for WQCV release and historic 10 year, 1 hour release for 100 year event). Since releases from the Compressor Station during a 100 year event will be less than or equal to historic 10 year, 1 hour release rate, downstream improvements should not be adversely impacted by the proposed Bayou Compressor Station, and the natural character of the area will be preserved. Crestone Project No. 19021 Page 1 14 BAYOU COMPRESSOR STATION: Final Drainage Report September 30, 2019 2. The Project Site is not included within a Master Drainage Plan and therefore, not impacted by previous plan requirements/recommendations. 3. The Project Site is not encumbered by irrigation facilities. 4. Please refer to Appendices A through D for specific technical criteria and references. VIII - REFERENCES 1. Weld County Code Ordinance 2019-12, Chapter 8 - Public Works, Article XI — Storm Drainage Criteria. 2. Weld County Engineering & Construction Guidelines, Updated July 2017. 3. Denver Urban Drainage and Flood Control District (UDFCD), Drainage Criteria Manual, Volume 1, January 2007, Volume 2, revised September 2017, Volume 3, revised April 2018. 4. Colorado Division of Water Resources - Administrative Statement Regarding the Management of Storm Water Detention Facilities and Post-Wildland Fire Facilities in Colorado, dated February 11, 2016. 5. Natural Resources Conservation Service (NRCS), Web Soil Survey Weld County Colorado, Northern Part, Version 13, September 10, 2018. 6. Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map #08123C0375E, dated January 20, 2016. Crestone Project No. 19021 Page 115 APPENDIX A General Information — Vicinity Map NRCS Soils Data FEMA — FIRM Map VICINITY MAP N Q d NOT TO SCALE PROJECT SITE IMAGE COURTESY OF WELD COUNTY, CO GIS, 2019 _WYOMING COLORADO x U WCR 128 M CC U •- .. WC R-Yi 4� - 40 U WCR 124 WCR 138 WCR 136 112 cc CC U N U r -- cc U WCR 130 Weld County GIS I Bure (Cr-- CRESTONE CONSULTANTS, tic evil engineering sohctwns 14143 West Warren Ccrcte 303-9976113 -%an. crestonzUc corn Lakewood, CO 80228 PROJECT: BAYOU COMPRESSOR STATION CAUTION THE ENGINEER PREPARING THESE PLANS AND CRESTONE CONSULTANTS, LLC. WILL NOT BE RESPONSIBLE FOR, OR LIABLE FOR UNAUTHORIZED CHANGES TO OR USES OF THESE PLANS ALL CHANGES TO THE PLANS MUST BE IN WRITING AND MUST BE APPROVED BY THE PREPARER OF THESE PI ANS TITLE: VICINITY MAP DATE: 08/2019 DRAWN BY: LJM VIC 40° 56' 46" N 40° 55' 32" N 104° 33 17 w 537700 warp 539603 I I I I 537700 538000 538300 saw I I l I I I I N A Map Scale: 1:16,100 d printed on A landscape (11" x 8.S") sheet. Soil Map —Weld County, Colorado, Northern Part (BAYOU COMPRESSOR STATION) 528800 533300 533203 538600 0 200 400 Feet 0 Si) 1000 2000 3000 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 800 Meters 1200 USDA Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 533833 540100 540100 540400 540700 541000 ° It 7/23/2019 Page 1 of 3 40° 56' 46' N 40° 55' 32" N Soil Map —Weld County, Colorado, Northern Part (BAYOU COMPRESSOR STATION) Area of Interest (AOI) Soils u Iowa MAP LEGEND Area of Interest (AO') Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features V X 0 X 0 A. 0 0 V • •. 0 0 0 Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails ti 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. 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, Northern Part Survey Area Data: Version 13, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Oct 22, 2014 —Oct 2, 2017 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. USDA Natural Resources S Conservation Service Web Soil Survey National Cooperative Soil Survey 7/23/2019 Page 2 of 3 Soil Map —Weld County, Colorado, Northern Part BAYOU COMPRESSOR STATION Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of A0I 4 Ascalon fine sandy loam, 0 to 6 percent slopes 119.5 13.8% 27 Epping silt loam, 0 to 9 percent slopes 176.2 20.4% 29 Haverson loam, 0 to 3 percent slopes 26.7 3.1% 31 Kim -Mitchell complex, 0 to 6 percent slopes 14.6 1.7% 32 Kim -Mitchell complex, 6 to 9 percent slopes 26.3 3.0% 34 Manter sandy loam, 0 to 6 percent slopes 128.8 14.9% 35 Manter sandy loam, 3 to 9 percent slopes 0.4 0.0% 54 Platner loam, 0 to 3 percent slopes 40.9 4.7% 61 Stoneham fine sandy loam, 0 to 6 percent slopes 31.2 3.6% 74 Vona sandy loam, 3 to 9 percent slopes 56.0 6.5% 75 Wages fine sandy loam, 0 to 6 percent slopes 243.1 28.1% Totals for Area of Interest 863.6 100.0% USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/23/2019 Page 3 of 3 Map Unit Description: Ascalon fine sandy loam, 0 to 6 percent slopes --Weld County. BAYOU GAS COMPRESSOR Colorado. Northern Part STATION Weld County, Colorado, Northern Part 4 —Ascalon fine sandy loam, 0 to 6 percent slopes Map Unit Setting National map unit symbol: 2t1p5 Elevation: 4,550 to 6,050 feet Mean annual precipitation: 12 to 17 inches Mean annual air temperature: 46 to 54 degrees F Frost -free period: 135 to 160 days Farmland classification: Farmland of statewide importance Map Unit Composition Ascalon and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ascalon Setting Landform: Interfluves Landform position (two-dimensional): Backslope. summit Landform position (three-dimensional): Interfluve Down -slope shape: Linear Across -slope shape: Linear Parent material: Wind -reworked alluvium and/or calcareous sandy eolian deposits Typical profile Ap - 0 to 7 inches: fine sandy loam Bt1 - 7 to 13 inches: sandy clay loam Bt2 - 13 to 18 inches: sandy clay loam Bk 18 to 48 inches: sandy loam C - 48 to 80 inches: sandy loam Properties and qualities Slope: 0 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline (0.1 to 1.9 mmhos/cm) Sodium adsorption ratio, maximum in profile: 1.0 Available water storage in profile: Moderate (about 6.8 inches) L.SD:\ Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description: Ascalon fine sandy loam, 0 to 6 percent slopes ---Weld County. BAYOU GAS COMPRESSOR Colorado, Northern Part STATION Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Minor Components Olnest Percent of map unit: 8 percent Landform: Interfluves Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down -slope shape: Linear Across -slope shape: Linear Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Otero Percent of map unit: 7 percent Landform: I nterfi uves Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down -slope shape: Linear Across -slope shape: Linear Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Data Source Information Soil Survey Area Weld County. Colorado. Northern Part Survey Area Data Version 13, Sep 10. 2018 SDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description_ Epping silt loam, 0 to 9 percent slopes ---Weld County. Colorado. BAYOU GAS COMPRESSOR Northern Part STATION Weld County, Colorado, Northern Part 27 Epping silt loam, 0 to 9 percent slopes Map Unit Setting National map unit symbol: 35zb Elevation: 3.600 to 5.500 feet Mean annual precipitation: 12 to 17 inches Mean annual air temperature: 45 to 52 degrees F Frost -free period: 120 to 150 days Farmland classification: Not prime farmland Map Unit Composition Epping and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations. descriptions, and transects of the mapunit. Description of Epping Setting Landform. Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous loamy residuum weathered from siltstone Typical profile H1 - 0 to 3 inches: silt loam H2 - 3 to 17 inches: silt loam H3 - 17 to 20 inches: weathered bedrock Properties and qualities Slope: 0 to 9 percent Depth to restrictive feature 10 to 20 inches to paralithic bedrock Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate. maximum in profile: 15 percent Available water storage in profile: Very low (about 2.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6s Hydrologic Soil Group: D Ecological site: Shallow Siltstone (R067BY039CO) Hydric soil rating: No L SDA a Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description. Epping silt loam, 0 to 9 percent slopes ---Weld County, Colorado, BAYOU GAS COMPRESSOR Northern Part STATION Minor Components Keota Percent of map unit: 5 percent Hydric soil rating: No Thedalund Percent of map unit: 4 percent Hydric soil rating: No Mitchell Percent of map unit: 3 percent Hydric soil rating: No Kim Percent of map unit: 3 percent Hydric soil rating: No Data Source Information Soil Survey Area. Weld County. Colorado. Northern Part Survey Area Data: Version 13. Sep 10. 2018 tSIM_ a Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description Haverson loam. 0 to 3 percent slopes ---Weld County. Colorado, BAYOU GAS COMPRESSOR Northern Part STATION Weld County, Colorado, Northern Part 29—Haverson loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 35zd Elevation: 3.500 to 6.000 feet Mean annual precipitation: 12 to 17 inches Mean annual air temperature: 46 to 54 degrees F Frost -free period: 125 to 180 days Farmland classification: Prime farmland if irrigated and either protected from flooding or not frequently flooded during the growing season Map Unit Composition Haverson and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations. descriptions. and transects of the mapunit. Description of Haverson Setting Landform. Flood plains, stream terraces Down -slope shape: Linear Across -slope shape: Linear Parent material: Stratified. calcareous loamy alluvium Typical profile H1 - 0 to 12 inches: loam H2 - 12 to 60 inches: stratified sandy loam to loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Gypsum, maximum in profile: 1 percent Salinity, maximum in profile: Nonsaline to moderately saline (0.0 to 8.0 mmhos/cm) Available water storage in profile: High (about 9.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4c Hydrologic Soil Group: B t_SDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description: Haverson loam, 0 to 3 percent slopes ---Weld County, Colorado. BAYOU GAS COMPRESSOR Northern Part STATION Ecological site: Overflow (R067BY036CO) Other vegetative classification: OVERFLOW (067BY036CO) Hydric soil rating: No Minor Components Nunn Percent of map unit: 6 percent Hydric soil rating: No Fluvaquentic haplustolls Percent of map unit: 4 percent Landform. Terraces Hydric soil rating: Yes Data Source Information Soil Survey Area: Weld County, Colorado. Northern Part Survey Area Data: Version 13. Sep 10. 2018 USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description: Kim -Mitchell complex, 0 to 6 percent slopes ---Weld County, Colorado, BAYOU GAS COMPRESSOR Northern Part STATION Weld County, Colorado, Northern Part 31 Kim -Mitchell complex, 0 to 6 percent slopes Map Unit Setting National map unit symbol: 35zh Elevation: 3,500 to 6,500 feet Mean annual precipitation: 11 to 17 inches Mean annual air temperature: 46 to 54 degrees F Frost -free period: 120 to 160 days Farmland classification: Farmland of statewide importance Map Unit Composition Kim and similar soils: 45 percent Mitchell and similar soils: 40 percent Minor components: 15 percent Estimates are based on observations. descriptions, and transects of the mapunit. Description of Kim Setting Landform: Alluvial fans. plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous loamy alluvium Typical profile H1 - 0 to 3 inches: loam H2 - 3 to 7 inches: clay loam /-13 - 7 to 60 inches: loam Properties and qualities Slope: 0 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: High (about 9.7 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: Loamy Plains (R067BY002CO) t SD.x r Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description: Kim -Mitchell complex. 0 to 6 percent slopes ---Weld County. Colorado. BAYOU GAS COMPRESSOR Northern Part STATION Hydric soil rating: No Description of Mitchell Setting Landform: Plains, alluvial fans Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous loamy alluvium Typical profile H1 - 0 to 7 inches: silt loam H2 - 7 to 60 inches: silt loam Properties and qualities Slope: 0 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Available water storage in profile: High (about 10.8 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: A Ecological site: Siltstone Plains (R067BY009CO) Hydric soil rating: No Minor Components Haverson Percent of map unit: 5 percent Hydric soil rating: No Thedalund Percent of map unit: 5 percent Hydric soil rating: No Keota Percent of map unit: 5 percent Hydric soil rating: No Data Source Information Soil Survey Area Weld County. Colorado. Northern Part Survey Area Data: Version 13. Sep 10. 2018 1 SDA Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description: Kim -Mitchell complex, 6 to 9 percent slopes ---Weld County Colorado, BAYOU GAS COMPRESSOR Northern Part STATION Weld County, Colorado, Northern Part 32 Kim -Mitchell complex, 6 to 9 percent slopes Map Unit Setting National map unit symbol: 35zi Elevation: 3,500 to 6,500 feet Mean annual precipitation: 11 to 17 inches Mean annual air temperature. 46 to 54 degrees F Frost -free period: 120 to 160 days Farmland classification: Not prime farmland Map Unit Composition Kim and similar soils: 45 percent Mitchell and similar soils: 35 percent Minor components: 20 percent Estimates are based on observations. descriptions, and transects of the mapunit. Description of Kim Setting Landform: Plains, fans, alluvial fans Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous loamy alluvium and/or colluvium Typical profile Hi - 0 to 3 inches: loam H2 - 3 to 7 inches: clay loam H3 - 7 to 60 inches: loam Properties and qualities Slope: 6 to 9 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity. maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: High (about 9.7 inches) Interpretive groups Land capability classification (irrigated): 6e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: C Ecological site: Loamy Plains (R067BY002CO) l'SDA a Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description Kim -Mitchell complex. 6 to 9 percent slopes ---Weld County, Colorado, BAYOU GAS COMPRESSOR Northern Part STATION Hydric soil rating: No Description of Mitchell Setting Landform: Plains, alluvial fans, fans Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous loamy alluvium Typical profile H1 - 0 to 7 inches: silt loam H2 - 7 to 60 inches: silt loam Properties and qualities Slope: 6 to 9 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile. 15 percent Available water storage in profile: High (about 10.8 inches) Interpretive groups Land capability classification (irrigated): 6e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: A Ecological site: Siltstone Plains (R067BY009CO) Hydric soil rating: No Minor Components Keota Percent of map unit: 7 percent Hydric soil rating: No Thedalund Percent of map unit: 7 percent Hydric soil rating: No Haverson Percent of map unit: 6 percent Hydric soil rating: No Data Source Information Soil Survey Area Weld County. Colorado. Northern Part Survey Area Data: Version 13. Sep 10. 2018 USDA Natural Resources Web Soil Survey r Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description: Manter sandy loam, 0 to 6 percent slopes —Weld County, Colorado, BAYOU GAS COMPRESSOR Northern Part STATION Weld County, Colorado, Northern Part 34—Manter sandy loam, 0 to 6 percent slopes Map Unit Setting National map unit symbol: 35z1 Elevation: 3,500 to 5,000 feet Mean annual precipitation: 16 to 18 inches Mean annual air temperature: 48 to 50 degrees F Frost -free period: 130 to 170 days Farmland classification: Farmland of statewide importance Map Unit Composition Manter and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Manter Setting Landform: Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous loamy alluvium Typical profile H1 - 0 to 3 inches: sandy loam H2 - 3 to 28 inches: fine sandy loam, sandy loam H2 - 3 to 28 inches: loamy sand H3 - 28 to 60 inches: Properties and qualities Slope: 0 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 10.4 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: A Ecological site: Sandy Plains (R067BY024CO) USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description: Manter sandy loam, 0 to 6 percent slopes ---Weld County. Colorado. BAYOU GAS COMPRESSOR Northern Part STATION Hydric soil rating: No Minor Components Julesburg Percent of map unit: 10 percent Hydric soil rating: No Data Source Information Soil Survey Area. Weld County, Colorado. Northern Part Survey Area Data: Version 13, Sep 10, 2018 Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description Platner loam. 0 to 3 percent slopes ---Weld County, Colorado, Northern BAYOU GAS COMPRESSOR Part STATION Weld County, Colorado, Northern Part 54—Platner loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2tIn0 Elevation: 4.000 to 4,930 feet Mean annual precipitation: 14 to 17 inches Mean annual air temperature: 46 to 50 degrees F Frost -free period: 135 to 160 days Farmland classification: Prime farmland if irrigated Map Unit Composition Platner and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions. and transects of the mapunit. Description of Platner Setting Landform: Interfluves Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Linear Across -slope shape: Linear Parent material: Mixed eolian deposits over tertiary aged alluvium derived from igneous. metamorphic and sedimentary rock Typical profile Ap - 0 to 6 inches: loam Bt1 - 6 to 11 inches: clay Bt2 - 11 to 20 inches: clay Bk1 - 20 to 27 inches: loam Bk2 - 27 to 37 inches: sandy clay loam C - 37 to 80 inches: sandy clay loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity maximum in profile: Nonsaline (0.0 to 1.0 mmhos/cm) Available water storage in profile: Moderate (about 8.1 inches) t cr),\ Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description: Platner loam 0 to 3 percent slopes ---Weld County. Colorado. Northern BAYOU GAS COMPRESSOR Part STATION Interpretive groups Land capability classification (irrigated): 3s Land capability classification (nonirrigated): 4s Hydrologic Soil Group: C Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Minor Components Ascalon Percent of map unit: 10 percent Landform. Interfluves Landform position (two-dimensional): Summit, shoulder Landform position (three-dimensional): Interfluve Down -slope shape: Linear Across -slope shape: Linear Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Rago, rarely flooded Percent of map unit: 4 percent Landform: Drainageways Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slopehead slope Down -slope shape: Linear Across -slope shape: Concave Ecological site: Overflow (R067BY036CO) Hydric soil rating: No Rago, ponded Percent of map unit: 1 percent Landform. Playas Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Concave Across -slope shape: Concave Ecological site: Closed Upland Depression (R067BY010CO) Hydric soil rating: No Data Source Information Soil Survey Area Weld County. Colorado. Northern Part Survey Area Data. Version 13, Sep 10. 2018 t.!SDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description: Stoneham fine sandy loam, 0 to 6 percent slopes --Weld County, BAYOU GAS COMPRESSOR Colorado, Northern Part STATION Weld County, Colorado, Northern Part 61 Stoneham fine sandy loam, 0 to 6 percent slopes Map Unit Setting National map unit symbol: 360k Elevation: 4,000 to 6,500 feet Mean annual precipitation: 12 to 16 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 130 to 170 days Farmland classification: Farmland of statewide importance Map Unit Composition Stoneham and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Stoneham Setting Landform: Alluvial fans, plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous loamy alluvium Typical profile H1 - 0 to 5 inches: fine sandy loam H2 - 5 to 8 inches: clay loam H3 - 8 to 14 inches: loam H4 - 14 to 60 inches: sandy loam, gravelly sandy loam H4 - 14 to 60 inches: Properties and qualities Slope: 0 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 11.2 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description: Stoneham fine sandy loam, 0 to 6 percent slopes --Weld County, BAYOU GAS COMPRESSOR Colorado, Northern Part STATION Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Minor Components Kim Percent of map unit: 5 percent Hydric soil rating: No Mitchell Percent of map unit: 5 percent Hydric soil rating: No Data Source Information Soil Survey Area: Weld County, Colorado, Northern Part Survey Area Data: Version 13, Sep 10, 2018 USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description: Vona sandy loam, 3 to 9 percent slopes ---Weld County. Colorado. BAYOU GAS COMPRESSOR Northern Part STATION Weld County, Colorado, Northern Part 74 —Vona sandy loam, 3 to 9 percent slopes Map Unit Setting National map unit symbol: 3610 Elevation: 4,000 to 5.500 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 55 degrees F Frost -free period: 130 to 160 days Farmland classification: Not prime farmland Map Unit Composition Vona and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations. descriptions. and transects of the mapunit. Description of Vona Setting Landforrn. Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous sandy alluvium and/or eolian deposits Typical profile H1 - 0 to 6 inches: sandy loam H2 - 6 to 15 inches: fine sandy loam sandy loam H2 - 6 to 15 inches: loamy sand H3 - 15 to 60 inches: Properties and qualities Slope: 3 to 9 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): High (1.98 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Moderate (about 7.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6e Hydrologic Soil Group: A Ecological site: Sandy Plains (R067BY024CO) tSDA a Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description. Vona sandy loam, 3 to 9 percent slopes ---Weld County. Colorado. BAYOU GAS COMPRESSOR Northern Part STATION Hydric soil rating: No Minor Components Remmit Percent of map unit: 8 percent Hydric soil rating: No Julesburg Percent of map unit: 4 percent Hydric soil rating: No Olney Percent of map unit: 3 percent Hydric soil rating: No Data Source Information Soil Survey Area' Weld County. Colorado. Northern Part Survey Area Data: Version 13. Sep 10. 2018 LDx Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 2 Map Unit Description: Wages fine sandy loam. 0 to 6 percent slopes ---Weld County. Colorado. BAYOU GAS COMPRESSOR Northern Part STATION Weld County, Colorado, Northern Part 75 —Wages fine sandy loam, 0 to 6 percent slopes Map Unit Setting National map unit symbol: 3611 Elevation: 3,900 to 5,600 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature. 46 to 52 degrees F Frost -free period: 135 to 155 days Farmland classification: Farmland of statewide importance Map Unit Composition Wages and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations. descriptions. and transects of the mapunit. Description of Wages Setting Landform: Alluvial fans, plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous loamy alluvium Typical profile H1 - 0 to 4 inches: fine sandy loam H2 - 4 to 14 inches: sandy clay loam H3 - 14 to 60 inches: loam H4 - 60 to 64 inches: sandy loamgravelly sandy loam H4 - 60 to 64 inches: Properties and qualities Slope: 0 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.20 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity. maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Moderate (about 8.7 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B USDA a Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 1 of 2 Map Unit Description: Wages fine sandy loam, 0 to 6 percent slopes ---Weld County. Colorado, BAYOU GAS COMPRESSOR Northern Part STATION Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Minor Components Platner Percent of map unit: 9 percent Hydric soil rating: No Kim Percent of map unit: 5 percent Hydric soil rating: No Mitchell Percent of map unit: 1 percent Hydric soil rating: No Data Source Information Soil Survey Area Weld County, Colorado. Northern Part Survey Area Data: Version 13. Sep 10. 2018 t,CDA Natural Resources Web Soil Survey am Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 2 40° 56'41'N 40° 55' 42" N Pl I04° 32 56 W 538000 538300 538600 Hydrologic Soil Group —Weld County, Colorado, Northern Part (BAYOU GAS COMPRESSOR STATION) 538900 1 Map crak: 1:12,700 if punted on A landscape (11" x 8.5") sheet. N 0 150 300 600 Meters 900 Feet 0 500 1000 2000 3000 Map proiection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 USDA Natural Resources a Conservation Service Web Soil Survey National Cooperative Soil Survey 540100 540400 540700 7/16/2019 Page 1 of 4 40° 56' 41' N 40° 55' 47 N Hydrologic Soil Group —Weld County, Colorado, Northern Part BAYOU GAS COMPRESSOR STATION Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in A0I Percent of AOI 4 Ascalon fine sandy loam, 0 to 6 percent slopes B 69.7 11.1 % 27 I Epping silt loam, 0 to 9 percent slopes D 147.0 23.4% 29 Haverson loam, 0 to 3 percent slopes B 17.4 2.8% L31 Kim -Mitchell complex, 0 to 6 percent slopes C 7.6 1.2% 32 Kim -Mitchell complex, 6 to 9 percent slopes C 26.2 4.2% 34 Manter sandy loam, 0 to 6 percent slopes A 112.2 17.8% 54 Platner loam, 0 to 3 percent slopes C 30.8 4.9% 61 Stoneham fine sandy loam, 0 to 6 percent slopes B 25.1 4.0% 74 Vona sandy loam, 3 to 9 percent slopes A 35.4 5.6% 75 Wages fine sandy loam, 0 to 6 percent slopes B 157.6 25.1% Totals for Area of Interest ' 629.0 100.0% USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 3 of 4 Hydrologic Soil Group —Weld County, Colorado, Northern Part BAYOU GAS COMPRESSOR STATION 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 C/D). 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, B/D, or C/D), 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 USDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 7/16/2019 Page 4 of 4 Physical Soil Properties ---Weld County, Colorado. Northern Part BAYOU GAS COMPRESSOR STATION Physical Soil Properties This table shows estimates of some physical characteristics and features that affect soil behavior. These estimates are given for the layers of each soil in the survey area. The estimates are based on field observations and on test data for these and similar soils. Depth to the upper and lower boundaries of each layer is indicated. Particle size is the effective diameter of a soil particle as measured by sedimentation. sieving. or micrometric methods. Particle sizes are expressed as classes with specific effective diameter class limits. The broad classes are sand, silt. and clay, ranging from the larger to the smaller. Sand as a soil separate consists of mineral soil particles that are 0.05 millimeter to 2 millimeters in diameter. In this table, the estimated sand content of each soil layer is given as a percentage. by weight. of the soil material that is less than 2 millimeters in diameter. Silt as a soil separate consists of mineral soil particles that are 0.002 to 0.05 millimeter in diameter. In this table, the estimated silt content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter. Clay as a soil separate consists of mineral soil particles that are less than 0.002 millimeter in diameter. In this table, the estimated clay content of each soil layer is given as a percentage. by weight, of the soil material that is less than 2 millimeters in diameter. The content of sand. silt. and clay affects the physical behavior of a soil. Particle size is important for engineering and agronomic interpretations, for determination of soil hydrologic qualities. and for soil classification. The amount and kind of clay affect the fertility and physical condition of the soil and the ability of the soil to adsorb cations and to retain moisture. They influence shrink -swell potential, saturated hydraulic conductivity (Ksat), plasticity, the ease of soil dispersion, and other soil properties. The amount and kind of clay in a soil also affect tillage and earthmoving operations. Moist bulk density is the weight of soil (ovendry) per unit volume. Volume is measured when the soil is at field moisture capacity, that is. the moisture content at 1/3- or 1/10 -bar (33kPa or 10kPa) moisture tension. Weight is determined after the soil is dried at 105 degrees C. In the table. the estimated moist bulk density of each soil horizon is expressed in grams per cubic centimeter of soil material that is less than 2 millimeters in diameter. Bulk density data are used to compute linear extensibility. shrink -swell potential. available water capacity. total pore space. and other soil properties. The moist bulk density of a soil indicates the pore space available for water and roots. Depending on soil texture, a bulk density of more than 1.4 can restrict water storage and root penetration. Moist bulk density is influenced by texture, kind of clay, content of organic matter, and soil structure. USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 1 of 8 Physical Soil Properties --Weld County, Colorado, Northern Part BAYOU GAS COMPRESSOR STATION Saturated hydraulic conductivity (Ksat) refers to the ease with which pores in a saturated soil transmit water. The estimates in the table are expressed in terms of micrometers per second. They are based on soil characteristics observed in the field, particularly structure, porosity, and texture. Saturated hydraulic conductivity (Ksat) is considered in the design of soil drainage systems and septic tank absorption fields. Available water capacity refers to the quantity of water that the soil is capable of storing for use by plants. The capacity for water storage is given in inches of water per inch of soil for each soil layer. The capacity varies, depending on soil properties that affect retention of water. The most important properties are the content of organic matter, soil texture, bulk density, and soil structure. Available water capacity is an important factor in the choice of plants or crops to be grown and in the design and management of irrigation systems. Available water capacity is not an estimate of the quantity of water actually available to plants at any given time. Linear extensibility refers to the change in length of an unconfined clod as moisture content is decreased from a moist to a dry state. It is an expression of the volume change between the water content of the clod at 1/3- or 1/10 -bar tension (33kPa or 10kPa tension) and oven dryness. The volume change is reported in the table as percent change for the whole soil. The amount and type of clay minerals in the soil influence volume change. Linear extensibility is used to determine the shrink -swell potential of soils. The shrink -swell potential is low if the soil has a linear extensibility of less than 3 percent; moderate if 3 to 6 percent; high if 6 to 9 percent; and very high if more than 9 percent. If the linear extensibility is more than 3, shrinking and swelling can cause damage to buildings, roads, and other structures and to plant roots. Special design commonly is needed. Organic matter is the plant and animal residue in the soil at various stages of decomposition. In this table, the estimated content of organic matter is expressed as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter. The content of organic matter in a soil can be maintained by returning crop residue to the soil. Organic matter has a positive effect on available water capacity, water infiltration, soil organism activity, and tilth. It is a source of nitrogen and other nutrients for crops and soil organisms. Erosion factors are shown in the table as the K factor (Kw and Kf) and the T factor. Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the average annual rate of soil loss by sheet and rill erosion in tons per acre per year. The estimates are based primarily on percentage of silt, sand, and organic matter and on soil structure and Ksat. Values of K range from 0.02 to 0.69. Other factors being equal, the higher the value, the more susceptible the soil is to sheet and rill erosion by water. Erosion factor Kw indicates the erodibility of the whole soil. The estimates are modified by the presence of rock fragments. Erosion factor Kf indicates the erodibility of the fine -earth fraction, or the material less than 2 millimeters in size. USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 2 of 8 Physical Soil Properties ---Weld County. Colorado, Northern Part BAYOU GAS COMPRESSOR STATION Erosion factor T is an estimate of the maximum average annual rate of soil erosion by wind and/or water that can occur without affecting crop productivity over a sustained period. The rate is in tons per acre per year. Wind erodibility groups are made up of soils that have similar properties affecting their susceptibility to wind erosion in cultivated areas. The soils assigned to group 1 are the most susceptible to wind erosion, and those assigned to group 8 are the least susceptible. The groups are described in the "National Soil Survey Handbook." Wind erodibility index is a numerical value indicating the susceptibility of soil to wind erosion, or the tons per acre per year that can be expected to be lost to wind erosion. There is a close correlation between wind erosion and the texture of the surface layer, the size and durability of surface clods, rock fragments, organic matter, and a calcareous reaction. Soil moisture and frozen soil layers also influence wind erosion. Reference: United States Department of Agriculture. Natural Resources Conservation Service. National soil survey handbook, title 430 -VI. (http://soils.usda.gov) USDA ism Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 3 of 8 Physical Soil Properties --Weld County, Colorado, Northern Part BAYOU GAS COMPRESSOR STATION Report Physical Soil Properties Three values are provided to identify the expected Low (L), Representative Value (R), and High (H). Physical Soil Properties —Weld County, Colorado, Northern Part Map symbol and soil name Depth Sand Slit Clay Moist bulk density Saturated hydraulic conductivity Available water capacity Linear extensibility Organic matter Erosion factors Wind erodibility group Wind erodibility index Kw Kf T In Pct Pct Pct g/ec micro m/sec iniin t ict Pct 4 —Ascalon fine sandy loam. 0 to 6 percent slopes Ascalon 0-7 56-65- 77 11-27- 39 15- 9- 12 1.53-1.56 -1.59 14.11-28.23-42. 34 0.13-0.14-0. 15 0.4- 0.8- 1.2 11.0- 1.0- 2.0 .28 .28 5 3 186 7-13 52-57- 63 12-18- 23 18-25- 27 1.50-1.56 -1.61 4.23-9.17-42.34 0.10-0.13-0. 13 1.9- 3.2- 3.6 0.5- 0.6- 1.0 .28 .28 13-18 52-57- 63 12-18- 23 18-25- 27 1.54-1.58 -1.62 4.23-9.17-42.34 0.10-0.13-0. 13 1.8- 3.2- 3.5 0.4- 0.5- 0.8 .28 .28 18-48 48-62- 68 11-21- 38 14-17- 21 1.45-1.54 -1.63 4.23-28.23-42.3 4 0.10-0.10-0. 15 1.3- 1.6- 2.4 0.2- 0.2- 0.5 .24 .24 48-80 58-68- 81 7-24- 39 3- 8- 12 1.53-1.60 -1.67 14.11-28.23-14 1.14 0.07-0.12-0. 14 0.2- 0.7- 1.1 0.1- 0.1- 0.2 .28 .28 27 —Epping silt loam, 0 to 9 percent slopes Epping 0-3 -30- -55- 10-15- 20 1.15-1.23 -1.30 4.00-23.00-42.0 0 0.15-0.18-0. 20 0.0- 1.5- 2.9 0.5- 0.8- 1.0 .43 .43 2 5 56 3-17 -29- -53- 10-18- 25 1.25-1.28 -1.30 4.00-23.00-42.0 0 0.14-0.17-0. 20 0.0- 1.5- 2.9 0.5- 0.8- 1.0 .55 .55 17-20 - - - - 0.42-1.00-1.41 - - - Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 4 of 8 Physical Soil Properties --Weld County, Colorado, Northern Part BAYOU GAS COMPRESSOR STATION Physical Soil Properties —Weld County, Colorado, Northern Part Map symbol and soil name Depth Sand Silt Clay Moist bulk density Saturated hydraulic conductivity Available water capacity Linear extensibility Organic matter Erosion factors Wind erodibility Wind erodibility index Kw Kf T group In Pct Pct Pct g/cc micro m/sec In/In Pct Pct 29-Haverson loam, 0 to 3 percent slopes Haverson 0-12 -43- -39- 10-19- 27 1.25-1.33 -1.40 4.00-23.00-42.0 0 0.14-0.16-0. 18 0.0- 1.5- 2.9 0.5- 1.3- 2.0 .37 37 5 5 56 12-60 -60- -22- 8-18- 30 1.35-1.38 -1.40 4.23-9.00-14.11 0.14-0.16-0. 18 0.0- 1.5- 2.9 0.0- 0.3- 0.5 .24 24 31 -Kim - Mitchell complex, 0 to 6 percent slopes I Kim 0-3 -42- -37- 15-21- 27 f 1.25-1.33 -1.40 4.00-23.00-42.0 10.14-0.16-0. 0 18 0.0- 1.5- 2.9 0.5- 0.8- 1.0 .32 .32 5 4L f 86 3-7 -32- -38- 20-30- 35 1.25-1.33 -1.40 1.41-3.00-4.23 0.16-0.18-0. 20 0.0- 1.5- 2.9 ' 0.5- 0.8- 1.0 .32 .32 7-60 -42- -37- 15-21- 27 1.25-1.33 -1.40 4.00-23.00-42.0 0 0.14-0.16-0. 18 0.0- 1.5- 2.9 0.0- 0.3- 0.5 .37 .37 Mitchell 0-7 -14- -70- 12-16- 20 1.15-1.23 -1.30 4.00-23.00-42.0 0 0.15-0.18-0. 20 0.0-1.5- 2.9 0.5- 0.8- 1.0 .49 .49 5 4L 86 7-60 -14- -72- 10-14- 18 1.15-1.23 -1.30 14.11-28.00-42. 33 0.15-0.18-0. 20 0.0-1.5- 2.9 0.5- 0.8- 1.0 .55 .55 USDA Natural Resources Web Soil Survey r Conservation Service National Cooperative Soil Survey 7/16/2019 Page 5 of 8 Physical Soil Properties --Weld County, Colorado, Northern Part BAYOU GAS COMPRESSOR STATION Physical Soil Properties —Weld County, Colorado, Northern Part Map symbol and soil name Depth Sand Silt Clay Moist bulk density Saturated hydraulic conductivity Available water capacity Linear extensibility Organic matter Erosion factors Wind erodibility group Wind erodibility index Kw Kf T In Pct Pct Pct g/cc micro m/sec In/In Pct Pct 32 —Kim - Mitchell complex, 6 to 9 percent slopes Kim 0-3 . -42- -37- 15-21- 27 1.25-1.33 -1.40 4.00-23.00-42.0 0 0.14-0.16-0. 18 0.0- 1.5- 2.9 0.5- 0.8- 1.0 .32 .32 5 4L 86 3-7 -32- -38- 20-30- 35 1.25-1.33 -1.40 1.41-3.00-4.23 0.16-0.18-0. 20 0.0- 1.5- 2.9 0.5- 0.8- 1.0 .32 .32 7-60 -42- -37- 15-21- 27 1.25-1.33 -1.40 4.00-23.00-42.0 10.14-0.16-0. 0 18 0.0- 1.5- 2.9 0.0- 0.3- 0.5 .37 .37 Mitchell 0-7 -14 -70- 12.16- 20 1.15-1.23 I -1.30 4.00-23.00-42.0 0 0.15-0.18-0. 20 0.0-1.5- 2.9 0.5- 0.8- 1.0 .49 .49 5 4L 86 7-60 -14- -72- 10-14 18 1.15-1.23 -1.30 14.11-28.00-42. 33 0.15-0.18-0. 20 0.0- 1.5- 2.9 0.5- 0.8- 1.0 .55 .55 34—Manter sandy loam, 0 to 6 percent slopes Manter 0-3 -66- -19- 10-15- 20 1.35-1.38 -1.40 14.11-28.00-42. 33 0.12-0.14-0. 16 0.0- 1.5- 2.9 2.0- 3.0- 4.0 .15 I .15 5 3 86 3-28 -67- -20- 9-14- 18 1.40-1.45 -1.50 14.11-28.00-42. 33 0.11-0.13-0. 14 0.0- 1.5- 2.9 1.0- 1.5- 2.0 .28 .28 28-60 -77- -17- 5- 6- 15 1.45-1.53 -1.60 14.11-28.00-42. 33 0.08-0.11-0. 14 0.0- 1.5- 2.9 0.0- 0.5- 1.0 .24 .24 t ,,n\ Natural Resources a Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 6 of 8 Physical Soil Properties ---Weld County, Colorado, Northern Part BAYOU GAS COMPRESSOR STATION Physical Soil Properties —Weld County, Colorado, Northern Part Map symbol and soil name Depth Sand Silt Clay Moist bulk density Saturated hydraulic conductivity Available water capacity Linear extensibility Organic matter Erosion factors Wind erodibility group Wind erodibility index Kw Kf T In Pct Pct Pd g/cc micro m/sec In/In Pot Pd 54—Platner loam, 0 to 3 percent slopes Platner 0-6 35-43- 50 28-38- 50 15-19- 22 1.33-1.41 4.23-9.17-42.34 0.14-0.15-0. 1.0- 2.0- 3.3 1.0- 1.5- .43 .43 5 5 5b -1.49 17 2.0 6-11 25-30- 42 13-30- 40 35-40- 45 1.32-1.36 0.42-0.92-1.41 0.13-0.15-0. 6.0- 7.3- 8.7 1.0- 1.5- .28 .28 -1.40 16 2.0 11-20 25-30- 42 13-30- 40 35-40- 45 1.32-1.36 0.42-0.92-1.41 0.13-0.15-0. 6.0- 7.3- 8.7 1.0- 1.5- .28 .28 -1.40 16 2.0 20-27 30-37- 55 11-37- 47 23-27- 34 1.45-1.56 1.41-9.17-14.11 0.12-0.17-0. 0.8- 1.3- 2.6 0.5- 0.8- .32 .32 -1.66 17 1.0 27-37 48-61- 72 3-19- 37 15-20- 25 1.41-1.54 4.23-9.17-42.34 0.10-0.12-0. 0.3- 0.9- 1.6 0.0- 0.5- .24 .24 -1.66 13 1.0 37-80 48-61- 72 3-19- 37 15-20- 25 1.47-1.58 4.23-9.17-42.34 0.10-0.12-0. 0.3- 0.9- 1.6 0.0- 0.5- .24 .24 -1.70 13 1.0 61 -Stoneham fine sandy loam,0to6 percent slopes Stoneham 0-5 -65- -20- 10-15- 20 1.35-1.43 14.11-28.00-42. 0.11-0.13-0. 0.0-1.5- 2.9 0.5- 0.8- .24 .24 5 3 86 -1.50 33 15 1.0 5-8 -35- -38- 20-28- 35 1.40-1.43 4.23-9.00-14.11 0.14-0.16-0. 3.0- 4.5- 5.9 0.5- 0.8- .32 .32 -1.45 18 1.0 8-14 -37- -37- 20-26- 35 1.40-1.43 4.23-9.00-14.11 0.14-0.16-0. 3.0- 4.5- 5.9 0.5- 0.8- .32 .32 -1.45 18 1.0 14-60 -66- -19- 10-15- 20 1.45-1.50 14.11-28.00-42. 0.08-0.10-0. 0.0- 1.5- 2.9 0.0- 0.3- .10 .24 -1.55 33 12 0.5 USDA Natural Resources a Conservation Service Web Soil Survey National Cooperative Soil Survey 7/16/2019 Page 7 of 8 Physical Soil Properties --Weld County, Colorado, Northern Part BAYOU GAS COMPRESSOR STATION Physical Soil Properties —Weld County, Colorado, Northern Part Map symbol and soil name Depth Sand Silt Clay Moist bulk density Saturated hydraulic conductivity Available water capacity Linear extensibility Organic matter Erosion factors Wind erodibility Wind erodibility index Kw Kf T group M Pct Pct Pct g/cc micro rn/sec In/In Pct Pct 74 -Vona sandy loam, 3 to 9 percent slopes Vona 0-6 -69- -24- 5- 8- 10 1.35-1.43 14.11-28.00-42. 0.10-0.12-0. 0.0- 1.5- 2.9 0.5- 0.8- .24 .24 ' 5 3 86 -1.50 33 13 1.0 6-15 -67- -20- 8-13- 18 1.40-1.45 14.11-28.00-42. 0.12-0.13-0. 0.0- 1.5- 2.9 0.5- 0.8- .28 .28 -1.50 33 14 1.0 15-60 -76- -18- 3- 6- 15 1.45-1.50 14.00-78.00-14 0.06-0.10-0. 0.0- 1.5- 2.9 0.0- 0.3- .24 .24 -1.55 1.00 13 I 0.5 75 —Wages fine sandy loam, 0 to 6 percent slopes Wages 0-4 -65- -20- 12-16- 20 1.35-1.43 4.00-23.00-42.0 0.10-0.12-0. 0.0- 1.5- 2.9 1.0- 2.0- .20 .20 5 3 86 -1.50 0 14 3.0 4-14 -49- -24- 20-28- 35 1.25-1.33 1.41-8.00-14.11 0.14-0.18-0. 0.0- 1.5- 2.9 1.0- 1.5- .24 .24 -1.40 21 2.0 14-60 -39- -37- 15-25- 35 1.25-1.38 1.41-8.00-14.11 0.12-0.14-0. 0.0- 1.5- 2.9 0.5- 0.8- .32 .32 I • -1.50 16 1.0 61)-tA -65- -19- 12-16- 20 1.25-1.38 4.00-23.00-42.0 0.07-0.10-0. 0.0- 1.5- 2.9 0.0- 0.3- .10 .24 -1.50 0 13 0.5 Data Source Information Soil Survey Area: Weld County, Colorado, Northern Part Survey Area Data: Version 13, Sep 10, 2018 t,ti1>.1 Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 7/16/2019 Page 8 of 8 National Flood Hazard Layer FIRMette 4CI 6 29 ') N 1:6,000 4056'2.57"N WELD COUNT 0802o1 500 T11N R64W S10 1,000 1,500 Zone D 0812300375E 1/20 /2016 NotPrinted FEMA U The National Map Oil oimagery. Data refreshed April. 2019. Feet 7_,000 Legend SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) 7onr A. V A94 With BFE or Depth Zone AE. AO. AM. VE. AR Regulatory Floodway OTHER AREAS OF FLOOD HAZARD M £L l£ l£ObOL ENO SCREEN] 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. • Area with Flood Risk due to Levee • Area of Minimal Flood Hazard Effective LOMRs OTHER AREAS Area of Undetermined Flood Hazard GENERAL - — - - Channel, Culvert, or Storm Sewer STRUCTURES milli Levee, Dike, or Floodwall OTHER FEATURES MAP PANELS 4 20.2 17.5 Cross Sections with 1% Annual Chance Water Surface Elevation Coastal Transect 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 N 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 9/2/2O19 at 6:28:32 PM 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. APPENDIX B Hydrologic Calculations (Historic & Developed Condition) — Rational Method Calculations Weighted "C" Calculations Weighted Slope Calculations Time of Concentration Runoff Calculations Hec-22 SCS (NRCS) Method Calculations Hydraflow Calculation Report Hydrologic Calculation Reference Materials Rational Formula (UDFCD) Time of Concentration (UDFCD) Percent Imperviousness Values (UDFCD) Comp C Runoff Coefficients (UDFCD) Weighted Slope (UDFCD) NOAA Atlas 14, Vol 8, Ver 2 — Point Precipitation Frequency Estimates (NOAA) Intensity -Duration Curves for Rational Method (UDFCD) AutoCAD Civil 3D Hydraflow Hydrographs Extension User's Guide - Computation Methods Estimating Runoff Curve Numbers (USDA) Rational Method Calculations Prgect No 19021 WEIGHTED "C' CALCULATIONS -REFERENCE UDSCM (VOL. 1) Table RO.3 - Recommended Percentage Imperviousness Values (200701) -REFERENCE UDSCM (VOL. 1), Equations RO-6 & RO-7 & Table RO-4 - Correction Factors Ka & Kcd for Use with Egatrons RO-6 & RO-7 (2007-01) Bayou Compressor Station Final Drainage Report Historic/ Open Space Roof, Drives & Walks Pavement, Pond Industrial (Light Areas Gravel Surfecin Channels/ Side Slopes 09/27/2019 6 19 AM % Impery SOIL HYDRO 2% 90% 100% 80% 40% 1 40% Total Area (hr) Total Area (Ac) Percent Impervious A SOIL AREA B SOIL AREA C/D SOIL AREA 2 year C 5 year C 10 year C 100 Year C BASIN GROUP Area Area Area Area Area Area H1 A & C/D 391,281 391,281 8.98 2.0% 5.36 3.62 0.00 0.06 0.15 0.33 OS1 A, B & C/D 965,147 13,392 978,539 I2.46 2,5% 7.48 0.88 14 10 0.01 0.11 0.20 0.41 052 A & CID 390,262 10,097 400,359 9.19 3.0% 3.06 6.13 0.01 0.11 0.20 0.42 053 A, B& C/D 10,556,080 356.006 10,912,086 250.51 3.2% 30.25 7.09.81 10.45 See Hec-22 SCS (Hydraflow) Calculations Dl A& C/D 2,054 66,455 322,772 391,281 8.98 50.0% 5 36 3.62 0.29 0.34 0.39 0.51 Creston° Consultants. 1.LC C Page 1 of 7 Project No 19021 Bayou Compressor Station Final Drainage Report WEIGHTED "SLOPE" CALCULATIONS -REFERENCE UDSCM (VOL. 1), Figure RO-10 - Slope Correction for Noturol & Gross -Lined Channels (2007-01) 0927/2019 E 19 AM TRAVEL SEGMENTS BASIN DESIGN POINT LENGTH 1 ft MEASURED SLOPE 1 % ADJUSTED SLOPE 1 % LENGTH 2 ft MEASURED SLOPE 2 % ADJUSTED SLOPE 2 % LENGTH 3 ft MEASURED SLOPE 3 % ADJUSTED SLOPE 3 % LENGTH 4 ft MEASURED SLOPE 4 % ADJUSTED SLOPE 4 % TOTAL LENGTH ft WEIGHTED SLOPE % H1 O51 O52 O53 Dl 1 2 3 4 1 132 1532 606 7910 24 1.75% 0.80% 1.00% 0.88% 25.00% 1 75% 0.80% 1 00% 0.88% 25.00% 77 807 557 543 606 5 20% 1.05% 0.53% 0.53% 1.50% 5.20% 1.05% 0.53% 0.53% 1.50% 442 172 987 514 1.95% 0.52% D.60% 0.50% 1.95% 0.52% 0.60% 0.50% 712 1.50% 1 50% 651 2511 1163 10152 1144 2.20% 0.80% 0.70% 0.90% 1.00% Crestone Consultants, LW Page 2 of 7 Project No. 19021 TIME OF CONCENTRATION Forest & Heavy Meadow Tillage/Field Bayou Compressor Station Final Drainage Report Watercourse Coefficient 2.5 Short Pasture & Lawns 5 Nearly Bare Ground 7 09/27/2019 6:19 AM Grassed Waterway 15 10 Paved Areas & Shallow Paved Swales 20 SUB -BASIN DATA INITIAL / OVERLAND TIME TRAVEL TIME T(t) T(c) & CHECK (URBANIZED BASINS) FINAL T(c) DESIGN DRAIN AREA C(5) Length Slope T(i) Length Slope Coeff. Vel T(t) COMP. TOTAL T(c) CHECK POINT BASIN ac ft % min ft % ft/s min T(c) LENGTH uorco A0 s min. 1 H1 8.98 0.06 300 2.2 25.07 351 2.2 7.0 1.0 5.63 30.70 651 N/A 30.70 2 O51 22.46 0.11 300 0.8 33.45 2211 0.8 7.0 0.6 58.49 91.94 2511 N/A 91.94 3 OS2 9.19 0.11 300 0.7 34.73 _ 863 0.7 7.0 0.6 24.38 59.11 _ 1163 N/A 59.11 4 OS3 250.51 See Hec-22 SCS (Hydraflow) Calculations 1 D1 8.98 0.34 24 1.0 6.72 1120 1.0 15.0 1.5 12.44 19.16 1144 16.36 16.36 Crestone Consultants, LLC Page 3of7 Project No. 19021 RUNOFF CALCULATIONS (Rational Method Procedure) Bayou Compressor Station Final Drainage Report I = 28.5P1/(10+Tc)°786 Rainfall Depth -Duration -Frequency (1 -hr) = (From NOAA Atlas 14, Vol 8, Ver 2 - Project Site) 0.89 Design Storm 2 Year REMARKS BASIN INFORMATION DIRECT RUNOFF TOTAL RUNOFF DESIGN POINT DRAIN BASIN AREA ac. RUNOFF COEFF T(c) min a C x A I in/hr Q cfs T(c) min SUM C x A I in/hr Q cfs 1 2 3 4 1 H1 OS1 OS2 OS3 D1 8.98 22.46 9.19 250.51 8.98 0.00 0.01 0.01 30.70 91.94 59.11 0.13 0.11 1.38 0.67 0.91 0.0 0.1 0.1 a 91.9 a 0.24 0.67 0.2 a Sum OS1 & OS2 See Hec-22 SCS (Hydraflow) Calculations I 0.29 16.36 2.57 1.94 5.0 09/27/2019 6:19 AM Crestone Consultants, LLC Page 4 of 7 Project No 19021 RUNOFF CALCULATIONS (Rational Method Procedure) Bayou Compressor Station Final Drainage Report I = 28.5P1/(10+Tdo.7s6 Rainfall Depth -Duration -Frequency (1 -hr) = (From NOAA Atlas 14, Vol 8, Ver 2 - Project Site) 1.17 Design Storm 5 Year REMARKS BASIN INFORMATION DIRECT RUNOFF TOTAL RUNOFF DESIGN POINT DRAIN BASIN AREA ac. RUNOFF COEFF T(c) min _ C x A I in/hr Q cfs T(c) min SUM C x A I in/hr Q cfs 1 2 3 4 1 H1 O51 O52 0S3 D1 8.98 22.46 9.19 250.51 8.98 0.06 0.11 0.11 30.70 91.94 59.11 0.54 2.39 1.04 1.81 0.88 1.19 1.0 2.1 1.2 91.9 3.42 0.88 3.0 Sum OS1 & OS2 See Hec-22 SCS (Hydraflow) Calculations 0.34 16.36 3.05 2.55 7.8 09/27/2019 6:19 AM Crestone Consultants, LLC Page 5 of 7 Project No. 19021 RUNOFF CALCULATIONS (Rational Method Procedure) Bayou Compressor Station Final Drainage Report I = 28.5P1/(10+T,)o.7s6 Rainfall Depth -Duration -Frequency (1 -hr) = From NOAA Atlas 14, Vol 8, Ver 2 - Project Site) 1.42 Design Storm 10 Year REMARKS BASIN INFORMATION DIRECT RUNOFF TOTAL RUNOFF DESIGN POINT DRAIN BASIN AREA ac. RUNOFF COEFF T(c) min C x A I in/hr Q cfs T(c) min SUM C x A I in/hr Q cfs 1 2 3 4 1 H1 OS1 O52 OS3 D1 8.98 22.46 9.19 250.51 8.98 0.15 0.20 0.20 30.70 91.94 59.11 1.32 4.43 1.87 2.20 1.07 1.45 2.9 4.7 2.7 91.9 6.31 1.07 6.7 Sum O51 & O52 See Hec-22 SCS (Hydraflow) Calculations 0.39 16.36 3.54 3.09 10.9 09/27/2019 6:19 AM Crestone Consultants, LLC Page 6of7 Project No. 19021 RUNOFF CALCULATIONS (Rational Method Procedure) Bayou Compressor Station Final Drainage Report I = 28.5P1/(10+Tc)o.7s6 Rainfall Depth -Duration -Frequency (1 -hr) = (From NOAA Atlas 14, Vol 8, Ver 2 - Project Site) 2.45 Design Storm 100 Year REMARKS BASIN INFORMATION DIRECT RUNOFF TOTAL RUNOFF DESIGN POINT DRAIN BASIN AREA ac. RUNOFF COEFF T(c) min C x A I in/hr Q cfs T(c) min SUM C x A I in/hr Q cfs 1 2 3 4 1 H1 O51 OS2 O53 D1 8.98 22.46 9.19 250.51 8.98 0.33 0.41 0.42 30.70 91.94 59.11 3.00 9.16 3.82 3.79 1.84 2.50 11.4 16.9 9.5 91.9 12.98 1.84 23.9 Sum OS1 & OS2 See Hec-22 SCS (Hydraflow) Calculations 0.51 16.36 4.57 5.34 24.4 09/27/2019 6:19 AM Crestone Consultants, LLC Page 7 of 7 Hec-22 SCS (NRCS) Method Calculations Hydraflow Table of Contents 19021 - Basin OS03.gpw Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk, Inc. v12 Friday, 09 / 27 / 2019 Watershed Model Schematic 1 Hydrograph Return Period Recap 2 2 - Year Summary Report 3 Hydrograph Reports 4 Hydrograph No. 1, SCS Runoff, OS3 4 TR-55 Tc Worksheet 5 5 - Year Summary Report 6 Hydrograph Reports 7 Hydrograph No. 1, SCS Runoff, OS3 7 10 -Year Summary Report 8 Hydrograph Reports 9 Hydrograph No. 1, SCS Runoff, OS3 9 100 - Year Summary Report 10 Hydrograph Reports 11 Hydrograph No. 1, SCS Runoff, OS3 11 IDF Report 12 1 Watershed Model Schematic Hydraflow Hydrographs Extension for AutoCAD® Civil 3O® 2018 by Autodesk, Inc. v12 C Legend Hyd. Origin Description 1 SCS Runoff OS3 Project: 19021 - Basin OS03.gpw Friday, 09 / 27 / 2019 2 Hydrograph Return Period R e C;a yorbthow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk, Inc. v12 Hyd. No. Hydrograph type (origin) Inflow hyd(s) Peak Outflow (cfs) Hydrograph 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr Description 1 SCS Runoff - -- 4.584 13.46 25.31 100.02 OS3 - Proj. file: 19021 - Basin OS03.gpw Friday, 09 / 27 / 2019 3 Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk, Inc. v12 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time I interval (min) Time to Peak (min) Hyd. volume (cuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph Description 1 SCS Runoff 4.584 2 840 105.011 - OS3 19021 - Basin OS03.gpw Return Period: 2 Year Friday, 09 / 27 / 2019 Hydrograph Report 4 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk. Inc. v12 Hyd. No. 1 OS3 Hydrograph type Storm frequency Time interval Drainage area Basin Slope Tc method Total precip. Storm duration = SCS Runoff = 2 yrs = 2 min = 250.510 ac = 0.0 % = TR55 = 1.74 in = 24 hrs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Friday. 09 / 27 / 2019 = 4.584 cfs = 840 min = 105.011 cuft = 68* = 0 f = 119.40 min = Type II = 484 Composite (Area/CN) = [(30.250 x 49) + (10.450 x 84) + (201.640 x 69) + (8.170 x 85)] / 250.510 Q (cfs) 5.00 4.00 3.00 2.00 1.00 OS3 Hyd. No. 1 -- 2 Year 0.00 _ 0 120 240 360 480 600 720 840 Hyd No. 1 960 1080 1200 1320 1440 1560 1680 Q (cfs) 5.00 4.00 3.00 2.00 1.00 0.00 Time (min) 5 TR55 Tc Worksheet Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk. Inc. v12 Hyd. No. 1 OS3 Description Sheet Flow Manning's n -value Flow length (ft) Two-year 24 -hr precip. (in) Land slope (%) Travel Time (min) Shallow Concentrated Flow Flow length (ft) Watercourse slope (%) Surface description Average velocity (ft/s) Travel Time (min) Channel Flow X sectional flow area (sqft) Wetted perimeter (ft) Channel slope (%) Manning's n -value Velocity (ft/s) A = 0.030 = 300.0 = 1.74 = 0.90 = 12.15 = 9852.00 = 0.90 = Unpaved =1.53 B 0.011 0.0 0.00 0.00 C 0.011 0.0 0.00 0.00 + 0.00 + 0.00 0.00 0.00 Paved 0.00 0.00 0.00 Paved 0.00 NMI Sib Totals 12.15 = 107.27 + 0.00 + 0.00 = 107.27 = 0.00 = 0.00 = 0.00 = 0.015 =0.00 0.00 0.00 0.00 0.015 0.00 0.0 0.00 0.00 0.00 0.015 0.00 Flow length (ft) ({0})0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc 119.40 min 6 Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk, Inc. v12 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to Peak (min) Hyd. volume (cuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph Description 1 SCS Runoff 13.46 2 812 234,757 — OS3 — 19021 - Basin OS03.gpw Return Period: 5 Year Friday, 09 / 27 / 2019 7 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk. Inc. v12 Hyd. No. 1 OS3 Hydrograph type Storm frequency Time interval Drainage area Basin Slope Tc method Total precip. Storm duration = SCS Runoff = 5 yrs = 2 min = 250.510 ac = 0.0% = TR55 = 2.18 in = 24 h rs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Friday. 09 / 27 / 2019 = 13.46 cfs = 812 min = 234.757 tuft = 68* =oft = 119.40 min = Type II = 484 Composite (Area/CN) = [(30.250 x 49) + (10.450 x 84) + (201.640 x 69) + (8.170 x 85)] / 250.510 Q (cfs) 14.00 12.00 10.00 8.00 6.00 4.00 2.00 OS3 Hyd. No. 1 -- 5 Year 0.00 _ 0 120 240 360 480 Hyd No. 1 600 720 840 960 1080 1200 1320 1440 1560 1680 Q (cfs) 14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 Time (min) 8 Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk, Inc. v12 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to Peak (min) Hyd. volume (cult) Inflow hyd(s) Maximum elevation (ft) Total strge used (cult) Hydrograph Description 1 SCS Runoff 25.31 2 802 384.792 OS3 - 19021 - Basin OS03.gpw Return Period: 10 Year Friday, 09 / 27 / 2019 9 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk. Inc. v12 Hyd. No. 1 OS3 Hydrograph type Storm frequency Time interval Drainage area Basin Slope Tc method Total precip. Storm duration = SCS Runoff = 10 yrs = 2 min = 250.510 ac = 0.0% = TR55 = 2.58 in = 24 h rs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Friday 09/27 / 2019 = 25.31 cfs = 802 min = 384.792 cuft = 68* = 0 f = 119.40 min = Type II = 484 Composite (Area/CN) = [(30.250 x 49) + (10.450 x 84) + (201.640 x 69) + (8.170 x 85)] / 250.510 Q (cfs) 28.00 24.00 20.00 16.00 12.00 8.00 4.00 OS3 Hyd. No. 1 -- 10 Year 0.00 _ 0 120 240 Hyd No. 1 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 Q (cfs) 28.00 24.00 20.00 16.00 12.00 8.00 4.00 0.00 Time (min) 10 Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk, Inc. v12 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to Peak (min) Hyd. volume (cult) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph Description 1 SCS Runoff 100.02 2 788 1,206,587 OS3 ---- 19021 - Basin OS03.gpw Return Period: 100 Year Friday. 09 / 27 / 2019 11 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3De 2018 by Autodesk. Inc. v12 Hyd. No. 1 OS3 Hydrograph type Storm frequency Time interval Drainage area Basin Slope Tc method Total precip. Storm duration = SCS Runoff = 100 yrs = 2 min = 250.510 ac = 0.0% = TR55 = 4.19 in = 24 hrs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Friday. 09 / 27 / 2019 = 100.02 cfs = 788 min = 1.206.587 tuft = 68* = 0 f = 119.40 m i n = Type II = 484 " Composite (Area/CN) = [(30.250 x 49) + (10.450 x 84) + (201.640 x 69) + (8.170 x 85)] / 250.510 Q (cfs) 120.00 100.00 80.00 60.00 40.00 20.00 0.00 0 OS3 Hyd. No. 1 -- 100 Year 120 240 Hyd No. 1 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 Q (cfs) 120.00 100.00 80.00 60.00 40.00 20.00 0.00 Time (min) Hydraflow Rainfall Report 12 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2018 by Autodesk, Inc. v12 Friday, 09 / 27 / 2019 Return Period (Yrs) Intensity -Duration -Frequency Equation Coefficients (FHA) B D E (N/A) 1 0.0000 0.0000 0.0000 2 31.1353 10.7000 0.8283 3 0.0000 0.0000 0.0000 5 47.8417 10.7000 0.8283 10 60.5767 10.7000 0.8283 25 74.9551 10.7000 0.8283 50 87.2794 10.7000 0.8283 100 98.2343 10.7000 0.8283 File name: 18021 - Williston PPFD-IDF.IDF Intensity = B / (Tc + D)AE Return Period Intensity Values (in/hr) (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2 3.18 2.53 2.12 1.83 1.61 1.45 1.31 1.20 1.11 1.04 0.97 0.91 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 4.89 3.89 3.25 2.81 2.48 2.22 2.02 1.85 1.71 1.59 1.49 1.41 10 6.19 4.92 4.12 3.55 3.13 i 2.81 2.55 2.34 2.17 2.02 1.89 1.78 25 7.66 6.09 5.09 4.39 3.88 3.48 3.16 2.90 2.68 2.50 2.34 2.20 50 8.92 7.09 5.93 5.12 4.52 4.05 3.68 3.38 3.12 2.91 2.72 2.56 100 10.04 7.98 6.67 5.76 5.08 4.56 4.14 3.80 3.52 3.27 3.07 2.89 Tc = time in minutes. Values may exceed 60. s\19021 - Outrigger Bayou Comoressor\Engineering\Drainage\Calculations\Hvdraflow\19022 - Bayou NOAA ISITE I.Dc Storm Distribution Rainfall Precipitation Table (in) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24 -hour 0.00 1.74 0.00 2.18 2.58 0.00 0.00 4.19 SCS 6 -Hr 0.00 1.31 0.00 1.71 2.09 0.00 0.00 3.66 Huff -1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff -2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff -3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff -4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hydrologic Calculation Reference Materials RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) District. Often the use of published flow data (available from the District) may make the need for additional hydrologic analysis along major drainageways for a particular study unnecessary. Statistical analyses may be used in certain situations. The use of this approach requires the availability of acceptable, appropriate, and adequate data. Calculations for the Rational Method can be carried out by hand or using the UD-Rational Spreadsheet that may be downloaded from the District's Web site (www.udfcd.orq). CUHP-SWMM calculations are extensive and are best carried out using the computer models provided by the District as an attachment to the CD version of this Manual or downloaded from the District's Web site. Most of this chapter focuses on the Rational Method and on the CUHP method in combination with SWMM routing. The Rational Method is generally used for smaller catchments when only the peak flow rate or the total volume of runoff is needed (e.g., storm sewer sizing or simple detention basin sizing). CUHP-SWMM is used for larger catchments and when a hydrograph of the storm event is needed (e.g., sizing large detention facilities). A summary of applicability of both the methods is provided in Table RO- Table RO-1 Applicability of Hydrologic Methods Watershed Size (acres) Is the Rational Method Applicable? Is CUHP Applicable? 0 to 5 Yes Yes (1) 5 to 90 Yes Yes (1) 90 to 160 Yes Yes 160 to 3,000 No Yes (2) Greater than 3,000 No Yes (if subdivided into smaller catchments) (2) (1) If one -minute unit hydrograph is used. (2) Subdividing into smaller sub -catchments and routing the resultant hydrographs using SWMM may be needed to accurately model a catchment with areas of different soil types or percentages of imperviousness. RO-2 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) 2.0 RATIONAL METHOD RUNOFF For urban catchments that are not complex and are generally 160 acres or less in size, it is acceptable that the design storm runoff be analyzed by the Rational Method. This method was introduced in 1889 and is still being used in most engineering offices in the United States. Even though this method has frequently come under academic criticism for its simplicity, no other practical drainage design method has evolved to such a level of general acceptance by the practicing engineer. The Rational Method properly understood and applied can produce satisfactory results for urban storm sewer and small on -site detention design. 2.1 Rational Formula The Rational Method is based on the Rational Formula: Q = CIA (RO-1) in which: Q = the maximum rate of runoff (cfs) C = a runoff coefficient that is the ratio between the runoff volume from an area and the average rate of rainfall depth over a given duration for that area 1= average intensity of rainfall in inches per hour for a duration equal to the time of concentration, 4 = area (acres) Actually, Q has units of inches per hour per acre (in/hr/ac); however, since this rate of in/hr/ac differs from cubic feet per second (cfs) by less than one percent, the more common units of cfs are used. The time of concentration is typically defined as the time required for water to flow from the most remote point of the area to the point being investigated. The time of concentration should be based upon a flow length and path that results in a time of concentration for only a portion of the area if that portion of the catchment produces a higher rate of runoff. The general procedure for Rational Method calculations for a single catchment is as follows: 1. Delineate the catchment boundary. Measure its area. 2. Define the flow path from the upper -most portion of the catchment to the design point. This flow path should be divided into reaches of similar flow type (e.g., overland flow, shallow swale flow, gutter flow, etc.). The length and slope of each reach should be measured. 3. Determine the time of concentration, rc, for the catchment. 2007-01 Urban Drainage and Rood Control District RO-3 RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) 4. Find the rainfall intensity, /, for the design storm using the calculated r,.. and the rainfall intensity - duration -frequency curve. (See Section 4.0 of the RAINFALL chapter.) 5. Determine the runoff coefficient, C. 6. Calculate the peak flow rate from the watershed using Equation RO-1. 2.2 Assumptions The basic assumptions that are often made when the Rational Method is applied are: 1. The computed maximum rate of runoff to the design point is a function of the average rainfall rate during the time of concentration to that point. 2. The depth of rainfall used is one that occurs from the start of the storm to the time of concentration, and the design rainfall depth during that time period is converted to the average rainfall intensity for that period. 3. The maximum runoff rate occurs when the entire area is contributing flow. However, this assumption has to be modified when a more intensely developed portion of the catchment with a shorter time of concentration produces a higher rate of maximum runoff than the entire catchment with a longer time of concentration. 2.3 Limitations The Rational Method is an adequate method for approximating the peak rate and total volume of runoff from a design rainstorm in a given catchment. The greatest drawback to the Rational Method is that it normally provides only one point on the runoff hydrograph. When the areas become complex and where sub -catchments come together, the Rational Method will tend to overestimate the actual flow, which results in oversizing of drainage facilities. The Rational Method provides no direct information needed to route hydrographs through the drainage facilities. One reason the Rational Method is limited to small areas is that good design practice requires the routing of hydrographs for larger catchments to achieve an economic design. Another disadvantage-otttye Rational Method is that with typical design procedures one normally assumes that all of the design flow is collected at the design point and that there is no water running overland to the next design point. However, this is not the fault of the Rational Method but of the design procedure. The Rational Method must be modified, or another type of analysis must be used, when analyzing an existing system that is under -designed or when analyzing the effects of a major storm on a system designed for the minor storm. RO-4 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF 2.4 Time of Concentration One of the basic assumptions underlying the Rational Method is that runoff is a function of the average rainfall rate during the time required for water to flow from the most remote part of the drainage area under consideration to the design point. However, in practice, the time of concentration can be an empirical value that results in reasonable and acceptable peak flow calculations. The time of concentration relationships recommended in this Manual are based in part on the rainfall -runoff data collected in the Denver metropolitan area and are designed to work with the runoff coefficients also recommended in this Manual. As a result, these recommendations need to be used with a great deal of caution whenever working in areas that may differ significantly from the climate or topography found in the Denver region. For urban areas, the time of concentration, to consists of an initial time or overland flow time, t;, plus the travel time, tt, in the storm sewer, paved gutter, roadside drainage ditch, or drainage channel. For non - urban areas, the time of concentration consists of an overland flow time, t„ plus the time of travel in a defined form, such as a swale, channel, or drainageway. The travel portion, tt, of the time of concentration can be estimated from the hydraulic properties of the storm sewer, gutter, swale, ditch, or drainageway. Initial time, on the other hand, will vary with surface slope, depression storage, surface cover, antecedent rainfall, and infiltration capacity of the soil, as well as distance of surface flow. The time of concentration is represented by Equation RO-2 for both urban and non -urban areas: t +t in which: = time of concentration (minutes) = initial or overland flow time (minutes) t, = travel time in the ditch, channel, gutter, storm sewer, etc. (minutes) 2.4.1 Initial Flow Time The initial or overland flow time, t;, may be calculated using equation RO-3: in which: C5WE S 0.33 t, = initial or overland flow time (minutes) C5 = runoff coefficient for 5 -year frequency (from Table RO-5) 2007-01 Urban Drainage and Flood Control District (RO-2) (RO-3) RO-5 RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) L = length of overland flow (500 ft maximum for non -urban land uses, 300 ft maximum for urban land uses) S = average basin slope (ft/ft) Equation RO-3 is adequate for distances up to 500 feet. Note that, in some urban watersheds, the overland flow time may be very small because flows quickly channelize. 2.4.2 Overland Travel Time For catchments with overland and channelized flow, the time of concentration needs to be considered in combination with the overland travel time, t,, which is calculated using the hydraulic properties of the swale, ditch, or channel. For preliminary work, the overland travel time, t,, can be estimated with the help of Figure RO-1 or the following equation (Guo 1999): (RO-4) in which: IF= velocity (ft/sec) C, = conveyance coefficient (from Table RO-2) S� = watercourse slope (ft/ft) Table RO-2—Conveyance Coefficient, C, Type of Land Surface Conveyance Coefficient, C, Heavy meadow 2.5 Tillage/field 5 Short pasture and lawns 7 Nearly bare ground 10 Grassed waterway 15 Paved areas and shallow paved swales 20 The time of concentration, tc, is then the sum of the initial flow time, t;, and the travel time, t:, as per Equation RO-2. 2.4.3 First Design Point Time of Concentration in Urban Catchments Using this procedure, the time of concentration at the first design point (i.e., initial flow time, t;) in an urbanized catchment should not exceed the time of concentration calculated using Equation RO-5. in which: RO-6 L +10 180 (RO-5) r� = maximum time of concentration at the first design point in an urban watershed (minutes) 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF L = waterway length (ft) Equation RO-5 was developed using the rainfall -runoff data collected in the Denver region and, in essence, represents regional "calibration" of the Rational Method. The first design point is the point where runoff first enters the storm sewer system. An example of definition of first design point is provided in Figure RO-2. Normally, Equation RO-5 will result in a lesser time of concentration at the first design point and will govern in an urbanized watershed. For subsequent design points, the time of concentration is calculated by accumulating the travel times in downstream drainageway reaches. 2.4.4 Minimum Time of Concentration Should the calculations result in a r, of less than 10 minutes, it is recommended that a minimum value of 10 minutes be used for non -urban watersheds. The minimum tL recommended for urbanized areas should not be less than 5 minutes and if calculations indicate a lesser value, use 5 minutes instead. 2.4.5 Common Errors in Calculating Time of Concentration A common mistake in urbanized areas is to assume travel velocities that are too slow. Another common error is to not check the runoff peak resulting from only part of the catchment. Sometimes a lower portion of the catchment or a highly impervious area produces a larger peak than that computed for the whole catchment. This error is most often encountered when the catchment is long or the upper portion contains grassy parkland and the lower portion is developed urban land. 2.5 Intensity The rainfall intensity, I, is the average rainfall rate in inches per hour for the period of maximum rainfall of a given recurrence frequency having a duration equal to the time of concentration. After the design storm's recurrence frequency has been selected, a graph should be made showing rainfall intensity versus time. The procedure for obtaining the local data and drawing such a graph is explained and illustrated in Section 4 of the RAINFALL chapter of this Manual. The intensity for a design point is taken from the graph or through the use of Equation RA -3 using the calculated t;,. 2.6 Watershed Imperviousness All pads of a watershed can be considered either pervious or impervious. The pervious part is that area where water can readily infiltrate into the ground. The impervious part is the area that does not readily allow water to infiltrate into the ground, such as areas that are paved or covered with buildings and sidewalks or compacted unvegetated soils. In urban hydrology, the percentage of pervious and impervious land is important. The percentage of impervious area increases when urbanization occurs 2007-01 Urban Drainage and Flood Control District RO-7 RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) and the rainfall -runoff relationships change significantly. The total amount of runoff volume normally increases, the time to the runoff peak rate decreases, and the peak runoff rates increase. Photograph RO-2—Urbanization (impervious area) increases runoff volumes, peak discharges, frequency of runoff, and receiving stream degradation. When analyzing a watershed for design purposes, the probable future percent of impervious area must be estimated. A complete tabulation of recommended values of the total percent of imperviousness is provided in Table RO-3 and Figures RO-3 through RO-5, the latter developed by the District after the evolution of residential growth patterns since 1990. 2.7 Runoff Coefficient The runoff coefficient, C, represents the integrated effects of infiltration, evaporation, retention, and interception, all of which affect the volume of runoff. The determination of C requires judgment and understanding on the part of the engineer. Based in part on the data collected by the District since 1969, an empirical set of relationships between C and the percentage imperviousness for the 2 -year and smaller storms was developed and are expressed in Equations RO-6 and RO-7-forTypn A rind CID -Soil groups (Urbonas, Guo and Tucker 1990) For Type B soil group the impervious value is found by taking the arithmetic average of the values found using these two equations for Type A and Type C/D soil groups. For larger storms (i.e., 5-, 10, 25-, 50- and 100 -year) correction factors listed in Table RO-4 are applied to the values calculated using these two equations. RO-8 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table RO-3--Recommended Percentage Imperviousness Values Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: Single-family* Multi -unit (detached) 60 Multi -unit (attached) 75 Half -acre lot or larger Apartments 80 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off -site flow analysis (when land use not defined) 45 Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 0 Lawns, clayey sod 0 * See Figures RO-3 through RO-5 for percentage imperviousness. KA + (I.31i3_I.44j2 + 1.135i - 0.12) for CA ≥ 0, otherwise C4= 0 (RO-6) Ca) = KCo + (0.858i 3 - 0.786i2 + 0.774i + 0.04) CB = CC A + Cco )I2 2007-01 Urban Drainage and Flood Control District (RO-7) RO-9 RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) in which: i = % imperviousness/100 expressed as a decimal (see Table RO-3) C4 = Runoff coefficient for Natural Resources Conservation Service (NRCS) Type A soils GB = Runoff coefficient for NRCS Type B soils Cu) = Runoff coefficient for NRCS Type C and D soils K4 = Correction factor for Type A soils defined in Table RO-4 IC") - Correction factor for Type C and D soils defined in Table RO-4 Table RO 4 Correction Factors K4 and K 0 for Use with Equations RO-6 and RO-7 7- NRCS Soil Type Storm Retum Period 2 -Year 5 -Year 10 -Year 25 -Year 50 -Year 100 -Year C and D 0 -0.101+0.11 -0.181+0.21 -0.281+0.33 -0.331+0.40 -0.391+0.46 A 0 -0.081+0.09 -0.141+0.17 -0.191+0.24 -0.221+0.28 -0.25i+0.32 The values for various catchment imperviousnesses and storm return periods are presented graphically in Figures RO-6 through RO-8, and are tabulated in Table RO-5. These coefficients were developed for the Denver region to work in conjunction with the time of concentration recommendations in Section 2.4. Use of these coefficients and this procedure outside of the semi -arid climate found in the Denver region may not be valid. The UD-Rational spreadsheet performs all the needed calculations to find the runoff coefficient given the soil type and imperviousness and the reader may want to take advantage of this macro -enabled Excel workbook that is available for download from the District's web site www.udfcd.orq under "Download" — "Technical Downloads." See Examples 7.1 and 7.2 that illustrate the Rational method. The use of the Rational method in storm sewer design is illustrated in Example 6.13 of the STREETS/INLETS/STORM SEWERS chapter. RO-10 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) Table RO-5— Runoff Coefficients, C RUNOFF Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0:39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47 0.53 15% 0.14 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% i 0.41 0.46 a 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 1 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 a 0.14 0.22 , 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 0.22 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 a 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% s 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 0.90 0.92 0.94 0.95 0.96 2007-01 Urban Drainage and Flood Control District RO-11 DRAINAGE CRITERIA MANUAL (V O Z TABLE RO-5 (Continued) —Runoff Coefficients, C Type A NRCS Hydrologic Soils Group I 1` O 0 r O N 0 4L:I' N 0 CO N 0 O Cr) 0 CO CO 0 u') CO 0 ti CO 0 Cr) Cr) 0 r- tt 0 CO e 0 Ui e 0 f-- e 0 O LC) 0 M O 0 co LO 0 r- CO 0 co CO 0 N 0 O ti 0 Co co 0 Co O) 0 8 CD 6 N 6 0.24 t` N 6 O M 6 N M 6 6 CD M 6 O M 6 Ot 0 N 6 0.45 117.0 r O ' QU LO O O) LC) O 0.64 O f� O N- f` O ULD CO O U) O) O ' , I N N r O co r- O 0.20 0.23 CO N 0 O) N 0 CO Cr) 0 LC) CO 0 I 1•••••O CO 0 le 0 N le 0 !o e 0 O `a' 0 C7` to 0 f U) 0 M CO 0 a) CO 0 co h 0 V CO 0 i t (5) 0 r Cr) 0 jr x LO OCD 0 O T- 0 'it r 0 LV0 0 N O 0.23 0.25 0.28 0 CO 6 0.33 0.35 CO CC`''i) 6 0.45 O) ct O 't O O O ((D O 0.73 OD N 6 0.92 1- ''' O O O O N O O CO O O O r O 0.13 CO r O O) r O N N O CC) N O 0.27 OM M 6 M 6 ti Cr) 6 r- e 6 O TT 6 O L 6 CO O 6 CO CO 6 r 1\ 6 0 co 6 0 C) 6 N 0 O O o O O O O O N O O CO O O Q) O O CO r O CO r O O) r O N N O 5t0 0.29 Cr) CO O f� CO O N O h tt O 0.54 r CO O O) CO O Cp 1` O CD CO O Percentage Imperviousness O O 0 LO 0 0 Or 0 0 r 0 0 ON 0 0 N 0 t MO 0 0 CO 0 c 0 0 0 0 LC) 0 0 lCf 0 0 C0O 0 0 C0 0 0 O� 75% 0',Si 0 CO 0 CO 0 0 O) 0 0 O 0 Or O N- O N cc U a O c 0 U v O 0 LL v c cv v O) Ca c 0 c co n RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) Where the flow -line slope varies along the channel, calculate a weighted basin slope for use with CUHP. Do this by first segmenting the major drainageway into reaches having similar longitudinal slopes. Then calculate the weighted slope using the Equation RO-9. 4 I; L`51 024 + L2,S2 0.24 + .... + Ln,Sn 0.4 L, + L2 + L3 ....Ln (RO-9) in which: S = weighted basin waterway slopes in ft/ft ,S:.....S,; = slopes of individual reaches in ft/ft (after adjustments using Figure RO-10) L:.L,. _ /,,i = lengths of corresponding reaches 6. Unit Hydrograph Time Increment —Typically a 5 -minute unit hydrograph is used. For catchments smaller than 90 acres, using a 1 -minute unit hydrograph may be needed if significant differences are found between the "excess precipitation' and 'runoff hydrograph° volumes listed in the summary output. For very small catchments (i.e. smaller than 10 acres), especially those with high imperviousness the 1 -minute unit hydrograph will be needed to preserve runoff volume integrity. 7. Pervious Retention —Maximum depression storage on pervious surfaces in inches. (See Section 3.2.2 for more details.) 8. Impervious Retention —Maximum depression storage on impervious surfaces in inches. (See Section 3.2.2 for more details.) 9. Infiltration Rate -Initial infiltration rate for pervious surfaces in the catchment in inches per hour. If this entry is used by itself, it will be used as a constant infiltration rate throughout the storm. (See Section 4.2.3 for more details.) 10. Decay —Exponential decay coefficient in Horton's equation in "per second" units 11. Final Infiltration —Final infiltration rate in Horton's equation in inches per hour. The program computes the coefficients C, and Cy; however, values for these parameters can be specified by the user as an option. The unit hydrograph is developed by the computer using the algorithm described in CUHP 2005 User Manual. The shaping of the unit hydrograph also relies on proportioning the widths at 50% and 75% of the unit hydrograph peak. The proportioning is based on 0.35 of the width at 50% of peak being ahead of the "time to peak" and 0.45 of the width at 75% of peak being ahead of the "time to peak." These RO-24 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) JO .08 .06 ta .04 .02 0 RUNOFF a -t 13R`L µ LS NAT NN�g W/0 GNEO� GRA'S G1� .02 .04 .06 .08 MEASURED SLOPE Kitt) J0 Figure RO-10-Slope Correction for Natural and Grass -Lined Channels 2007-01 Urban Drainage and Flood Control District J2 RO-27 NOAA Atlas 14, Volume 8, Version 2 Location name: Grover, Colorado, USA' Latitude: 40.9384°, Longitude: -104.5284° Elevation: 5425.18 ft" ' source ESRI Maps " source USGS POINT PRECIPITATION FREQUENCY ESTIMATES San)a Pence Deborah Martin Sandra Pavlovtc, ithanr Roy, Michael St. Laurent. Can Trypatuk, Dale Unruh, Michael Veins. Geoffery Bonnin NOAA. National Weather Service_ Silver Spring, Maryland PF tabular I PF graphical I Maos & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Average recurrence interval (years) Duration 1 2 5 10 25 50 100 200 500 1000 al 5-m i n 0.255 (0 199-0.3294 0.306 (0.238-0.395) 0.397 (0.308-0 514) 0.480 (0.370.0.624) 0.606 (0.457-0.823) 0.712 (0.522-0.9744 0.826 (0.585-1.15) 0.948 (0.645-1.351) 1.12 (0.735-1.64) 127 (0.803-1.86) 10 -min 0.374 (0 291-0.482)j 0.448 (0.349-0.578A 0.581 (0 451-0 752) 0.703 (0.542-0.913) 0.887 (0 669-1.21) 1.04 (0.765.1.43) 1.21 (0.857-1.69) 1.39 (0.945-1.98) 1.65 (1.08-2.40) (1.18-2.72) 1.85 15 -min 0.456 )1j (0.355-0.588 0.646 (0.425-0705) 0.709 (0.550-0.917) 0.867 (0662-1.11) 1.08 (0 816-1.47) 1.27 (0.933-1.74) 1.47 (1.05-2.06) 1.69 (1-15-242) 2.01 (1.31-2.93) 2.26 (1.43331) 0.602 0.724 0.942 1.14 1.43 1.88 1.94 2.22 2.63 2.95 30 -min (0 469.0 777) 40 564-0.936) (0 731-1 22) (0 878-1.48) (1.08.1 94) (1 23-2 29) (1.38-2.71) (1.513 17) (1 72-3 82) (1.87-4 32) I60 -min 0131 (0 570-0.943 0.887 (0.691-1.15) 1.17 (0.904-1.51) I 1.42 (1.09.1.84) 1.80 (1.35-2.44) 2.11 I (1.55-2.89) 2.45 (1.74-3.42) 2.82 (1.91-4 01) 3.33 (2.18-4 86) 3.75 (2.38-5.49 2 -hr 0.859 1.05 (0.827-1.34) 1.39 (1.09.1.78) 1.70 (1.32-2 18) 2.16 (1.65-2.90) 2.55 (1.89-3.44) 2.96 (2.12.4.08) 3.41 (2.34-4.80) 4.04 (2.67.5.81) 4,55 (2.923.58) 00.678-1.10) 3 -hr 0.931 (0,739-1.18) ` 1.14 (0.902-1.44) 1.51 (1 19-1.92) 1.85 (1,45-2.36) 2.36 (1.81-3.15) 2.79 (2.09-3.75) 3.26 (2.35-4.46) 3.76 (2.60-5.26) 4.47 (2.98-6.39) 5.05 (3.26-7.25) ' 6 -hr 1.08 (0 870.1.36) I 1.31 (1 05-1.64) 1.71 (1.37-2 15) 2.09 (1 66-2.63) 2.66 (2.07-3.50) 3.14 (2.38-4.16 I 3.66 , 2 6 7 4 95) 4.22 (2.96-5 84) I 5.03 (2.40-7.11) 5.69 (3.72-8 07 12 -hr 1.28 (1.04-1.58) 1.51 I (1.23-1.87) 1.94 (1.57-2.40) 2.32 (1 87.2.89) 2.90 (2 28-3.76) a 3.38 (2.59-4.42) 3.91 (2.89-5.20) 4.47 (3.17.6.08) 5.27 I (3.59-7.32) 5.91 I (3.91-8.26) 150 1.74 2.18 f 2.58 3.17 3.67 4.19 4.76 5.57 6.22 24 -hr (1.23-1,83) (143.2131 (178-2.671 l (210-3.171 (2.52.4.05) 12.84.4.721 I (3.14.5.51)1(3.42.6.391 13.85.7.841 (4.17-8.58 2 -day 1.70 (1.41-2 05) 2.00 (1 68-2 42) 2.52 (2 09.3 05) 2.97 (2 44.3.60) 3.61 (2.88-4 52) 4.12 (322-5 22) 4.86 (3 52-6 01) 5.22 (3 78.8.88) 6.00 (4 18-8 08) 6.60 (4.48-8 98) 3 -day 1.88 (1 57-2 25) 2.20 (1 84-2 63) 2.73 (2 28.3.28) 3.19 (2 65.3 84) 3.85 11(3.09.4 77) 4.37 (3 43-5.48) 4.91 (3 73.6.28) 5.47 (3 99-7 15) 6.24 (4.38-8.34) 6.84 (4.68-9 24) 4 -day 2.03 (1.71-2-421 2.35 (1.98-2.80) 2.90 (2.43-3.46) 3.36 (2.804 03) 4.03 (3.26.4-97) 4.56 (3.80-5.67) 5.10 (3.89-6.48) 5.66 (4.15-7.35) 6.43 (4.54-8.54) 7.03 (4.83.943) 7•day 2.37 (2.01-2.79) 2.72 (2.31-3.21) 3.31 r.80.3.91 3.81 (3214.51) 4.50 (3.875.48) 8.05 (4.02-6.21) 5.60 (4.32-7.02) 6.17 (4.57-7.91) 6.94 (4.94-9.09)I 7.52 (5.23-9.98i 10 -day 2.66. (2.27-3.11) (2.60-3.57) 3.05 I 3.68 f 3.14-4.32) I 4.21 (3.57-4.98) 4.95 4.05-5.97) 5.51 I (4 42-8.73) J 8.08 (4 72.7. ( 6.66 4.96-8-47) 7.43 (5.33.9.66) I 8.02 I (5 60-10.6, 1 20 -day 3.48 (3.02.4.02) 3.97 (3.44-4.60) 4.76 (4.11-5.52) 5.41 (4 643 28) 6.27 1 (5.18-7.42) 6.91 (5 603.29) 7.54 (5 91-9 22) 8.16 (8.15-10.2) 8.96 (E.50-11.5) 9.55 (6.77-12.4) 30 -day AAAA 14.17 I (3.64-4.78) J 4.75 (4.14-5.45) 5.67 (4.93-6.52) I 6.40 I (5.53.7.39) 7.37 I (6.13-8.64) 8.08 (6.59.9.59) 8.75 (6.91.10.6) 9.41 (7.13-11.6) 10.2 17.47.12.9) 101 (7.72-13.9) 145 -day if JI 5.04 (4.43-5 74) I 5.74 (5 04.6 53) 6.82 (5.97-7 78) 7.68 (6 67.8 77) 8.75 (7 33-10 2) . 9.53 (7 82-11 2) 10.3 (8 15-12.3) 11.0 (8.35-13.4) 11.8 (8.85.14 7) 12.3 (8.88-15 8) 60 -day 4 5.79 (5 12-6.55) 6.58 (5.81.7 45) 7.79 (6 86-8 84) 8.73 (7 64-9 94) 9.92 (834-11 4) 10.8 (8.87-12.6) 11.5 (9.20.13.7) � 1 12.2 (9.37-14.9) 13.1 (964-16.2) 13.6 (9 83-17 2) ' Preapitation frequency (PF) estimates n this table are based on frequency analysts of partial duration senes (PDS) Numbers in parenthesis ere 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 checkea 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 Ton ciol 01 >I3ee NOAA Atlas 14. Volume 8. Version 2 Created IGMT) Thu Jul 25 22 35 49 201 Average recurrence interval (years) Precipitation depth (in) N A CO CO O N C IIIIIII Ii t' - f • 1 PS. !Vii-+ 5533 1IIIIIIII O, a 41 N a b a ;i4.1 - 1141 Eg O C A 10 -min 15 -min 2 -hr 3 -hr 6 -hr n 12 -hr 2 -day 3 -day 4 -day 7 -day 10 -day 20 -day 30 -day 45 -day 60 -day N Precipitation depth (in) A at OD 0 111111111 0 0 0 0 0 CM 0 O O O O 0 7 i m -7 a O 0 r OEa i as m m a n 0 = (O et we Va el r 0 O 7 m c m ac m m m n o`< A O N A A s n C m Maps & aerials Small scale terrain I • I Large scale terrain t 0sitsz • Chfennt _.S I • Grteley 4345m. •Longmont Bounder• Illipr---s-T1 J A Denver ll N 1 Large scale map Back to Top Large scale aerial US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East nest HIgnway Silver Spnnq MD 20910 Questions') HDSC.Questions,^anoaa.aov Disclaimer RAINFALL DRAINAGE CRITERIA MANUAL (V. 1) 4.0 INTENSITY -DURATION CURVES FOR RATIONAL METHOD To develop depth -duration curves or intensity -duration curves for the Rational Method of runoff analysis take the 1 -hour depth(s) obtained from Figures RA -1 through RA -6 and multiply by the factors in Table RA -4 to determine rainfall depth and rainfall intensity at each duration. The intensity can then be plotted as illustrated in Figure RA -15. TABLE RA -4 --Factors for Preparation of Intensity -Duration Curves Duration (minutes) 5 10 15 T 30 60 Rainfall Depth at Duration (inches) 0.29P, 0.45P, 0.57P, 0.79P, 1.0P1 Intensity (inches per hour) 3.48P, 2.70P, 2.28P, 1.58P1 1.0P1 Alternatively, the rainfall intensity for the area within the District can be approximated by the equation: 28.5 P, / _ (10+Tine in which: / = rainfall intensity (inches per hour) P1= 1 -hour point rainfall depth (inches) Te = time of concentration (minutes) RA -6 (RA -3) 01/2004 Urban Drainage and Flood Control District AutoCAD Civil 3D Hydraflow Hydrographs Extension User's Guide x N N 'd O ® 2010 Autodesk, Inc. All Rights Reserved. Except as otherwise permitted by Autodesk, Inc., this publication, or parts thereof, may not be reproduced in any form, by any method, for any purpose. Certain materials included in this publication are reprinted with the permission of the copyright holder. 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All other brand names, product names or trademarks belong to their respective holders. Disclaimer THIS PUBLICATION AND THE INFORMATION CONTAINED HEREIN IS MADE AVAILABLE BY AUTODESK, INC. "AS IS." AUTODESK, INC. DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE REGARDING THESE MATERIALS. Published By: Autodesk, Inc. 111 McInnis Parkway San Rafael, CA 94903, USA Computational Methods This section describes the methodology used in AutoCAD Civil 3D Hydraflow Hydrographs Extension for the calculations of hydrographs, rainfall IDF curves, channel, and pond routing. Review the following computational methods and equations to better understand the results. Hydrologic Methods Hydraflow Hydrographs Extension uses the HEC-22, Soil Conservation Service, SCS (now called Natural Resources Conservation Service, NRCS), and the Rational methods for most hydrologic calculations. These methods have become the industry standard among practicing engineers and state agencies. This section provides a summary of the concepts used by Hydraflow Hydrographs Extension. The following publications have been consulted when implementing the various hydrologic calculation methods: • NEH-4: Hydrology; Section 4, National Engineering Handbook • TR-20: Computer Program Manual, 1992 • TR-SS: Urban Hydrology For Small Watersheds • A Guide To Hydrologic Analysis Using SCS Methods, Richard McCuen • HEC No. 12: FHA, Drainage of Highway Pavements • NEC No. 22: FHA, Urban Drainage Design Manual • Hydrology for Engineers; Linsley, Kohler & Paulhus • Urban Storm Drainage Management; Sheaffer, Wright, Taggart & Wright • Handbook of Hydraulics; Brater, King, Lindell, Wei Computing SCS Unit Hydrograph Hydraflow Hydrographs Extension uses the unit hydrograph method for calculating runoff hydrographs. It uses the triangular D -hour unit hydrograph approach as used in TR-20. The unit hydrograph represents a 1 -inch rainfall over one time interval. The peak flow for the unit hydrograph is computed using the following equation: 73 Qp_ 484.4O Tp Where: Qp = peak flow (cfs) 484 = shape factor A = area (sq. miles) Q = total excess precipitation (1 inch) Tp = time to peak (hrs) The shape factor is a user defined variable. The default value is 484 and reflects a unit hydrograph that has 3/8 of its area under the rising limb. This factor is higher (for example, 600) in mountainous watersheds, and lower (approximately 300) in flat and swampy watersheds. TIP If you don't know the exact value of the shape factor, leave the default. The time to peak (Tp) and the time base (Tb) values determine the characteristics of the unit hydrograph. Hydraflow Hydrographs Extension computes these values using the following equations: _ Tc + D Tp 1.7 Where: Tp = time to peak (hrs) Tc = time of concentration (hrs) D = unit duration or time interval (hrs) Tc = 1.67 x L (lag time) L=19S+1T- 19060 5 Where: L = lag time (hrs) I = hydraulic length (ft) S=(1000/CN)-10 Y = basin slope (%) CN = SCS curve number Tb =2.67Tp Where: Tb = time base (hrs) Tp = time to peak (hrs) After the unit hydrograph ordinates have been computed, Hydraflow Hydrographs Extension lets you change the unit duration or time interval (D). This feature is useful when the input time interval (D) is too large 74 I Chapter 3 Computational Methods related to the time to peak (Tp). Normally, the time interval (D) value should not exceed the time to peak (Tp) value by more than 0.5 times. When you change time interval (D), Hydraflow Hydrographs Extension recomputes time to peak (Tp) so that it falls on an even increment of the new time interval. In the following example of a unit hydrograph (which represents one inch of rainfall over one time interval), peak flow (Qp) = 75, time to peak (Tp) = 24 min, time base (Tb) = 2.64 (24) = 64 min. Q (cfs) 80 60 40 20 0 0 12 24 36 48 60 72 min Computing Time of Concentration You can compute the time of concentration (Tc) by hand and input it directly. You can also override the precomputed Tc by selecting Lag, User, Kirpich or TR-55 under Time of Concentration in the SCS Runoff Hydrograph and Rational Method Hydrograph dialog boxes. Lag Method This is the TR-20 default method. Te =1.67L Where: L = lag time Kirpich Method This method is normally used for natural basins with well defined routes for overland flow along bare earth or mowed grass roadside channels. This method is similar to the Lag method, but typically gives shorter times. Tc = 0.0078E -- S 385 Where: Tc = time of concentration (min) L = hydraulic length (ft) S = average basin slope (ft/ft) User Method This method allows you to override the computed time of concentration (Tc) value and enter a value manually. Computing Time of Concentration 175 TR-55 Method This method allows you to compute Tc by using the 3 -component Tc as used by TR-55. Hydraflow Hydrographs Extension has a built-in TR-55 worksheet that computes Tc. See Computing Tc by TR-55 on page 21. Tc = SheetFlowlime + ShalloweoncFloirTinte + C'hannelFlo►rTime Sheet flow time (Tsheet) (hrs) 0.007 (inLJ2 Tsheet = P2°5 so.-' Where: n = Manning's roughness coefficient L = flow length (must be <= 300 ft per TR-55) P2 = two-year 24 -hr rainfall (in) S = land slope (%) Shallow concentrated flow time (Tshallow) (hrs) Tshallow = 36001' Where: L = flow length (ft) V = average velocity (ft/s) and le = Cp ►S' Where: V = average velocity (ft/s) Cp = 20.3282 paved surfaces Cp = 16.1345 unpaved surfaces S = watercourse slope (ft/ft) Channel flow time (Tchannel) (hrs) Tchannel = 36001' Where: L = flow length (ft) V = average velocity (ft/s) and 1.1.49R2 35 = °` 11 76 I Chapter 3 Computational Methods Where: V = average velocity (ft/s) R = hydraulic radius (ft) = a/wp S = channel slope (ft/ft) (entered as %) N = Manning's roughness coefficient Computing Design Storms To calculate the direct runoff hydrograph, you need an excess precipitation hyetograph. There are several ways to specify the design storm, most of which are the SCS 24 -hour and 6 -hour distributions. Other options include the synthetic storm, Huff, and the custom storm. SCS 24 -Hour Distributions Hydraflow Hydrographs Extension provides the SCS 24 -hr distributions in any time interval you specify. The incremental rainfall amounts are computed from a polynomial equation. This equation is used with coefficients that vary depending on the elapsed time of the storm: Pi= Co + C'1T +C, T"+C3T' Where: Pt = fraction of 24 -hour precipitation T = elapsed time (hrs) CO = coefficient Cl = coefficient C2 = coefficient C3 = coefficient You can obtain the coefficient values from the Soil Conservation Service or NRCS. Synthetic Storms The Synthetic Storm option can produce an infinite number of design storm hyetographs. For each combination of the time interval and total storm duration, Hydraflow Hydrographs Extension can derive a design storm. Hydraflow Hydrographs Extension uses the rainfall IDF curves to compute depth increments over the time intervals. From these data, the design storm is constructed by placing the maximum depth increment near the center of the storm and arranging the other increments in a symmetrical alternating form. The Perfect Storm The Synthetic Storm can be perfectly matched to the site, because the total duration can be specified to better fit the computed time of concentration (Tc). For example, if Tc is 30 minutes, you could specify a one -hour storm rather than a 24 -hour storm. This way, the storm lasts long enough so that the entire drainage area contributes to flow to the most downstream point. Going beyond Tc only adds unnecessary volume and calculation resources. Computing Design Storms 177 To plot this storm at the SCS runoff plot • On the toolbar, click (Open Event Manager). Excess Precipitation Hyetograph The precipitation increments of the specified storm, including the SCS, synthetic, Huff, and the custom storms directly input, are converted to excess precipitation using the following equation: O=(P-o.2sj (P+o.8s) Where: Q = excess volume of precipitation (in) P = accumulated precipitation (in) S = potential maximum retention = (1000 / CN) - 10 CN = SCS curve number The computed volumes are converted to excess increments which are used in the final excess precipitation hyetograph. Computing Rainfall IDF Curves Hydraflow Hydrographs Extension builds its rainfall IDF curves from user -supplied data. If you are using map data (FHA method), Hydraflow Hydrographs Extension computes rainfall intensity values based on the methods presented in HEC-12 (FHWA Hydraulic Engineering Circular No. 12, Drainage of Highway Pavements). The FHA Method The calculation methods for the Eastern and Central United States are different from the Western region. IMPORTANT This method does not produce 1- or 3 -year return periods. Eastern and Central States Precipitation values for the 2 -year and 100 -year frequencies of 5-, 15-, and 60 -minute durations are required for input. Hydraflow Hydrographs Extension uses these values and the following equations to estimate values for 10- and 30 -minute durations. 10 -min value = 0.59 x (15 min) + 0.41 x (5 min) 30 -min value = 0.49 x (60 min) + 0.51 x (15 min) The following equations are used to compute values for return periods between the 2- and 100 -year frequencies: 5-yr = 0.278 x (100-yr) + 0.674 x (2-yr) 10-yr = 0.449 x (100-yr) + 0.496 x (2-yr) 25-yr = 0.669 x (100-yr) + 0.293 x (2-yr) 50-yr = 0.835 x (100-yr) + 0.146 x (2-yr) 78 1 Chapter 3 Computational Methods Once the rainfall volumes for the 2 -year through 100 -year frequencies of 5-, 10-, 15-, 30-, and 60 -minute durations are computed, Hydraflow Hydrographs Extension converts them to intensity values in inches per hour. Western States Precipitation values required for input are the 24 -hour and 6 -hour durations for the 2 -year and 100 -year frequencies. Hydraflow Hydrographs Extension uses these values and the following equations to compute 60 -min duration values: Y2 = 0.218 + 0.709 x [X1 (X1/X2)j Y100 = 1.897 + 0.439 x [X3 (X3/X4)] - 0.008 x Z Where: Y2 = 2-yr, 60 -min value Y100 = 100-yr, 60 -min value X1 = 2-yr, 6 -hr value X2 = 2-yr, 24 -hr value X3 = 100-yr, 6 -hr value X4 = 100-yr, 24 -hr value Z = point elevation in hundreds of feet Hydraflow Hydrographs Extension uses a built-in nomograph to compute precipitation amounts for return periods between the 2 -year and 100 -year frequencies. Hydraflow Hydrographs Extension then applies built-in ratios to convert the 60 -min volumes to 5-, 10-, 15-, and 30 -min volumes. See HEC-12. The rainfall volumes are then converted to intensities in inches per hour. Equation Coefficients Hydraflow Hydrographs Extension computes rainfall intensity for any time duration or time of concentration (Tc), using the FHA equation: I= (Tc+D)E B Hydraflow Hydrographs Extension computes the coefficients B, D, and E using a log -log interpolation of the rainfall intensity values, which plots to an almost straight line. Next, Hydraflow Hydrographs Extension uses a trial -and -error process to determine a constant D, which is added to corresponding time of concentration (Tc) values, allowing the line to plot straight. The coefficient B is the ordinate at t = 1. The coefficient E is the slope of the plotted line. This procedure is repeated for each frequency. Using Existing IDF Curves to Develop Coefficients You can derive your own equation coefficients in case the computed ones do not exactly match those that you are accustomed to. Simply reverse the procedure described in Equation Coefficients. To develop custom coefficients 1 Plot your existing rainfall intensity - duration curve(s) on log -log paper. 2 Find the values B, D, and E and enter them into Hydraflow Hydrographs Extension. Using Existing IDF Curves to Develop Coefficients 179 3 Normally, the initial plotted line is not straight. If it plots straight, then D = 0. Otherwise, select a constant D, such as 5, for example. 4 Add this value to each of the time of concentration (Tc) ordinates and replot the line. 5 If the line is straight, D = 5. If it is not straight, try different constants until the line is straight. B is then the intensity at Tc = 1, while E is the slope of the plotted IDF line. 6 Edit the IDF curve coefficients to match the ones derived and save. Third Degree Polynomial Equation Hydraflow Hydrographs Extension has the option of creating IDF curves using a third-degree polynomial equation as follows: I=A++fl +1,1' Where: I = rainfall intensity (in/hr) (cm/hr) X = I.n (time duration in minutes) A = coefficient B = coefficient C = coefficient D = coefficient Appropriate values for X are 8 to 180 minutes. Computing SCS Runoff Hydrographs At ter computing the excess precipitation hyetograph, Hydraflow Hydrographs Extension computes the direct runoff hydrograph using the concept of convolution or linear superpositioning. Each increment of the design storm hyetograph is multiplied by each ordinate of the unit hydrograph. The resulting hydrographs are then added or superimposed to obtain a final runoff hydrograph. Computing SBUH Runoff Hydrographs The SBUH method is similar to the SCS method. It is based on the curve number (CN) and uses SCS equations for computing soil absorption and precipitation excess. The SCS method works by converting the incremental runoff depths (precipitation excess) for a given basin and design storm hydrographs of equal time base according to the basin time of concentration (Tc) and adds them to form the final runoff hydrograph. The SBUH method converts the incremental runoff depths into instantaneous hydrographs which are then routed through an imaginary reservoir with a time delay equal to the basin Tc. When computing a runoff hydrograph, the SBUH method doesn't involve an intermediate step (a unit hydrograph). There are two steps of creating the final runoff hydrograph: 1 Computing the instantaneous hydrograph. The instantaneous hydrograph (I(t)) at each time interval (dt) is computed as follows: 80 I Chapter 3 Computational Methods Chapter 2 Estimating Runoff Technical Release 55 Urban Hydrology for Small Watersheds Table 2-2a Runoff curve numbers for urban areas I/ Cover type and hydrologic condition Curve numbers for Cover description hydrologic soil group Average percent impervious area 21 A Fully developed urban areas (vegetation established) Open space (lawns, parks, golf courses, cemeteries, etc.) al: Poor condition (grass cover < 50%) 68 79 86 89 Fair condition (grass cover 50% to 75%) 49 69 79 84 Good condition (grass cover > 75%) 39 61 74 80 Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way) 98 98 98 98 Streets and roads: Paved; curbs and storm sewers (excluding right-of-way) 98 98 98 98 Paved: oven ditches (including right-of-wavl 83 89 92 93 Gravel (including right-of-way) 76 85 89 91 Dirt (including right-of-way) 72 82 87 89 Western desert urban areas: Natural desert landscaping (pervious areas only) if 63 77 85 88 Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 2 -inch sand or gravel mulch and basin borders) 96 96 96 96 Urban districts: Commercial and business 85 89 92 94 95 Industrial 72 81 88 91 93 Residential districts by avenge lot size: 1/8 acre or less (town houses) 65 77 85 90 92 1/4 acre 38 61 75 83 87 1/3 acre 30 57 72 81 86 1/2 acre 25 54 70 80 85 1 acre 20 51 68 79 84 2 acres 12 46 65 77 82 Developing urban areas Newly graded areas (pervious areas only, no vegetation) f...... ..... Idle lands (CN's are determined using cover types similar to those in table 2-2c). 77 86 91 94 1 Average runoff condition, and 1, = 0.2S. 2 The average percent impervious area shown was used to develop the composite CN's. Other assumptions are as follows: impervious areas are directly connected to the drainage system, impervious areas have a CN of 98, and pervious areas are considered equivalent to open space in good hydrologic condition. CN's for other combinations of conditions may be computed using figure 2,`3 or 2-4. 3 CN's shown are equivalent to those of pasture. Composite CN's may be computed for other combinations of open space cover type. 4 Composite CN's for natural desert landscaping should be computed using figures 2-3 or 2-4 based on the impervious area percentage (CN = 98) and the pervious area CN. The pervious area CN's are assumed equivalent to desert shrub in poor hydrologic condition. 6 Composite CN's to use for the design of temporary measures during grading and construction should be computed using figure 2-3 or 2-4 based on the degree of development (impervious area percentage) and the CN's for the newly graded pervious areas. (210-Vl-TR-55, Second Ed., June 1986) 2-5 Chapter 2 Estimating Runoff Technical Release 55 Urban Hydrology for Small Watersheds Table 2-2b Runoff curve numbers for cultivated agricultural lands V Cover type Treatment V Curve numbers for Cover description hydrologic soil group Hydrologic condition W A B C D Fallow Bare soil Crop residue cover (CR) Row crops Small grain Close seeded or broadcast legumes or rotation meadow Straight row (SR) SR + CR Contoured (C) C+CR Contoured & terraced (C&T) C&T+ CR SR SR+CR C C+CR C&T C&T+ CR SR C C&T — 77 86 91 94 Poor 76 85 90 93 Good 74 83 88 90 Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good Poor Good 72 81 88 91 67 78 85 89 71 80 87 90 64 75 82 85 70 79 84 88 65 7 5 82 86 69 78 83 87 64 74 81 85 66 74 80 82 62 71 78 81 65 73 79 81 61 70 77 80 &SOFISR133882'�'aS .92 8cw 3 g S 76 84 88 75 83 87 76 83 86 72 80 84 74 82 85 73 81 84 73 81 84 72 80 83 72 79 82 70 78 81 71 78 81 69 77 80 77 85 89 72 81 85 75 83 85 69 78 83 73 80 83 67 76 80 I Average runoff condition, and 1a=0.2S 2 Crop residue cover applies only if residue is on at least 5% of the surface throughout the year. 3 Hydraulic condition is based on combination factors that affect infiltration and runoff, including (a) density and canopy of vegetative areas, (b) amount of year-round cover, (c) amount of grass or close -seeded legumes, (d) percent of residue cover on the land surface (good ≥ 20%), and (e) degree of surface roughness. Poor. Factors impair infiltration and tend to increase runoff. Good: Factors encourage average and better than average infiltration and tend to decrease runoff. (210-VI-TR-55, Second Ed., June 1986) Chapter 2 Estimating Runoff Technical Release 55 Urban Hydrology for Small Watersheds Table 2-2c Runoff curve numbers for other agricultural lands I. Cover type Curve numbers for Cover description hydrologic soil group Hydrologic condition A B C D Pasture, grassland, or range -continuous forage for grazing. 21 Meadow —continuous grass, protected from grazing and generally mowed for hay. Brush —brush -weed -grass mixture with brush the mAjor element. Woods —grass combination (orchard or tree farm). W Woods. &' Farmsteads —buildings, lanes, driveways, and surrounding lots. Poor 68 79 86 89 Fair 49 69 79 Good 39 61 74 84 1 80 30 58 71 78 Poor 48 67 77 83 Fair 35 56 70 77 Good 30 y 48 65 73 Poor 57 73 82 86 Fair 43 65 76 82 Good 32 58 72 79 Poor 45 66 77 83 Fair 36 60 73 79 Good 30 I/ 55 70 77 59 74 82 86 Average runoff condition, and Ia = 0.2S. 2 Poor: <5096) ground cover or heavily grazed with no mulch. Fair 50 to 75% ground cover and not heavily grazed. Good: > 75% ground cover and lightly or only occasionally grazed. 3 Poor. <5096 ground cover. Fair: 50 to 7596 ground cover. Good: >7596 ground cover. 4 Actual curve number is less than 30; use CN = 30 for runoff computations. G CN's shown were computed for areas with 50% woods and 50% grass (pasture) cover. Other combinations of conditions may be computed from the CN's for woods and pasture. 6 Poor Forest litter, small trees, and brush are destroyed by heavy grazing or regular burning. Fair Woods are grazed but not burned, and some forest litter covers the soil. Good: Woods are protected from grazing, and litter and brush adequately cover the soil. (210-VI-TR-55, Second Ed., June 1986) 2-7 Chapter 2 Estimating Runoff Technical Release 56 Urban Hydrology for Small Watersheds Table 2-2d Runoff curve numbers for arid and semiarid rangelands I/ Cover type Curve numbers for Cover description hydrologic soil group Hydrologic condition at A y B C D Herbaceous —mixture of grass, weeds, and low growing brush, with brush the minor element. Oak -aspen —mountain brush mixture of oak brush, aspen, mountain mahogany, bitter brush, maple, and other brush. Pinyon -juniper —pinyon, juniper, or both; grass understory. Sagebnish with grass understory. Desert shrub —major plants include saltbush, greasewood, creosotebush, blackbrush, bursage, palo verde, mesquite, and cactus. Poor Fair Good Poor Fair Good Poor Fair Good Poor Fair Good 80 87 93 71 81 89 62 74 85 66 74 79 48 57 63 30 41 48 75 85 89 58 73 80 41 61 71 67 80 85 51 63 70 35 47 55 Poor 63 77 85 88 Fair 55 72 81 86 Good 49 68 79 84 Average runoff condition, and I,,, = 0.2S. For range in humid regions, use table 2-2c. Poor. <3096 ground cover (litter, grass, and brush overstory). Fair. 30 to 70% ground cover. Good: > 7096 ground cover. 3 Curve numbers for group A have been developed only for desert shrub. r4 (210-V1-TR-55, Second Ed., June 1986) APPENDIX C Hydraulic Calculations (Developed Condition) — Channel Sizing Calculations Culvert Sizing Calculations Riprap Sizing Calculations Detention Pond Sizing Calculations Hydraulic Calculation Reference Materials Channel Manning's n Values (UDFCD) Riprap Sizing (UDFCD/USACE) Calculation of WQCV (UDFCD) Channel Sizing Calculations Channel Report Hydraflow Express Extension for Autodesk+A®AutoCAD® Civil 3O® by Autodesk. Inc. Channel 1 (CH1) - Design Flow = 9.4 cfs [Capacity] *See Note Below User -defined Invert Elev (ft) Slope (%) N -Value Calculations Compute by: Known Q (cfs) = 100.00 = 1.00 = 0.070 Known Q = 9.40 Highlighted Depth (ft) 0 (cfs) Area (sqft) Velocity (ft/s) Wetted Perim (ft) Crit Depth, Yc (ft) Top Width (ft) EGL (ft) (Sta, El, n)-(Sta, El, n)... ( 0 00. 101.82)-(18.80. 101.00. 0.070)-(22.80. 100.00.0 070)-(27.80, 100.00. 0.070)-(31.80. 101.00. 0 070)-(72.70. 101.82. 0.070) Sunday Sep 1 2019 = 0.80 = 9.400 = 6.56 = 1.43 = 11.60 = 0.43 = 11.40 = 0.83 Portion of Basin D1 is Tributary to Channel CH1 = 38% of Overall Basin D1 Area, Therefore, O100 = 0.38 x 24.4 cfs = 9.4 cfs Elev (ft) 102.00 101.50 101 00 100.50 100.00 9950 Section Depth (ft) 5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 2.00 1.50 1.00 0.50 0.00 -0.50 Sta (ft) Channel Report Hydraflow Express Extension for Autodesk® AutoCAD®® Civil 3D® by Autodesk. Inc Channel 1 (CH1) - Design Flow = 9.4 cfs [Velocity] User -defined Invert Elev (ft) Slope (%) N -Value Calculations Compute by: Known Q (cfs) = 100.00 = 1.00 = 0.035 Known Q = 9.40 See Note Below Highlighted Depth (ft) Q (cfs) Area (sqft) Velocity (ft/s) Wetted Perim (ft) Crit Depth. Yc (ft) Top Width (ft) EGL (ft) (Sta, El, n)-(Sta, El, n)... ( 0 00. 101.82)-(18.80, 101.00. 0.035)-(22.80, 100.00. 0.035)-(27.80, 100.00. 0.035)-(31.80. 101.00, 0.035)-(72.70. 101.82, 0.035) Sunday Sep 1 2019 = 0.56 = 9.400 = 4.05 = 2.32 = 9.62 = 0.43 = 9.48 = 0.64 ' Portion of Basin D1 is Tributary to Channel CH1 = 38% of Overall Basin D1 Area. Therefore. O100 = 0.38 x 24.4 cfs = 9.4 cfs Elev (ft) 102.00 101.50 101 00 100.50 100.00 99.50 Section Depth (ft) V 5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 2.00 1.50 1.00 0.50 0.00 -0.50 Sta (ft) Culvert Sizing Calculations Culvert Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk. Inc. Storm 1 (STM1) - Design Flow = 12.7 cfs ' See Note Below Invert Elev Dn (ft) Pipe Length (ft) Slope (%) Invert Elev Up (ft) Rise (in) Shape Span (in) No. Barrels n -Value Culvert Type Culvert Entrance Coeff. K,M,c,Y,k Embankment Top Elevation (ft) Top Width (ft) Crest Width (ft) Etc. tit 6+1900 Sai CC 5416 CC St•5 X 414:1 4413 r.. = 5414.81 = 80.20 = 0.52 = 5415.23 = 24.0 = Circular = 24.0 1 = 0.025 = Circular Corrugate Metal Pipe = Projecting = 0.034, 1.5, 0.0553, 0.54, 0.9 = 5418.92 = 40.00 = 750.00 Storm 1 )SIM1) Design Flow - 12.7 cfs Calculations Qmin (cfs) Qmax (cfs) Tailwater Elev (ft) Highlighted Qtotal (cfs) °pipe (cfs) °overtop (cfs) Veloc Dn (ft/s) Veloc Up (ft/s) HGL Dn (ft) HGL Up (ft) Hw Elev (ft) Hw/D (ft) Flow Regime Friday. Sep 27 2019 = 12.70 = 12.70 = (dc+D)/2 = 12.70 = 12.70 = 0.00 = 4.61 = 4.04 = 5416.45 = 5417.46 = 5417.94 = 1.36 = Outlet Control it,. Depth 1L In C•rCV ar L -4L. N' u MjL. ec Emou+• 12U 130 *Neal tit) T 23 +23 -223 ' Portion of Basin OS3 Tributary to Culvert = 50% of Overall Basin OS3 Area, Therefore. Q10 = 0.50 x 25.3 cfs = 12.7 cfs Culvert Report Hydraflow Express Extension for Autodesk® AutoCAD® civil 3O® by Autodesk. Inc, Storm 2 (STM2) - Design Flow = 12.7 cfs • See Note Below Invert Elev Dn (ft) Pipe Length (ft) Slope (%) Invert Elev Up (ft) Rise (in) Shape Span (in) No. Barrels n -Value Culvert Type Culvert Entrance Coeff. K,M,c,Y,k Embankment Top Elevation (ft) Top Width (ft) Crest Width (ft) tie. ,L St,! :9 di -41E CC 5413 Cr., Stu CC = 5415.29 = 78.70 = 0.65 = 5415.80 = 24.0 = Circular = 24.0 = 1 = 0.025 = Circular Corrugate Metal Pipe = Headwall = 0.0078, 2, 0.0379, 0.69.. 0.5 = 5418.92 = 40.00 = 750.00 Swim 2 (STM2) Design Flow a 12.7 cts Calculations Qmin (cfs) Qmax (cfs) Tailwater Elev (ft) Highlighted Qtotal (cfs) Qpipe (cfs) Qovertop (cfs) Veloc Dn (ft/s) Veloc Up (ft/s) HGL Dn (ft) HGL Up (ft) Hw Elev (ft) Hw/D (ft) Flow Regime Friday . Sep 27 2019 = 12.70 = 12.70 = (dc+D)/2 = 12.70 = 12.70 = 0.00 = 4.61 = 4.04 = 5416.93 = 5417.92 = 5418.31 = 1.25 = Outlet Control ft* pet) .L tacet:cr.'a t0 Craw Cuvat 80 Embank 7c, IV) Rencn it 320 2 2C 2r -0 SC .1 C Portion of Basin OS3 Tributary to Culvert = 50% of Overall Basin OS3 Area, Therefore, Q10 = 0.50 x 25.3 cfs = 12.7 cfs Weir Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk. Inc. Access Road Weir (Basin OS3) - Q100 = 100 cfs Trapezoidal Weir Crest Bottom Length (ft) Total Depth (ft) Side Slope (z:1) Calculations Weir Coeff. Cw Compute by: Known Q (cfs) Depth (ft) 1.00 0.50 0.00 -0.50 = Sharp = 750.00 = 0.39 = 4.00 = 3.10 Known Q = 100.00 Highlighted Depth (ft) Q (cfs) Area (sqft) Velocity (ft/s) Top Width (ft) Access Road Weir (Basin OS3) - Q100 = 100 cfs Friday. Sep 27 2019 = 0.13 = 100.00 = 97.57 = 1.02 = 751.04 v • 0 100 Weir 200 300 W.S. 400 500 600 700 800 900 1000 Depth (ft) 1.00 0.50 0.00 0.50 Length (ft) Channel Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk Inc. Access Road Weir (Basin OS3) - Q100 = 100 cfs User -defined Invert Elev (ft) Slope (%) N -Value Calculations Compute by: Known Q (cfs) = 5418.92 = 2.00 = 0.070 Known Q = 100.00 Highlighted Depth (ft) Q (cfs) Area (sqft) Velocity (ft/s) Wetted Perim (ft) Crit Depth. Yc (ft) Top Width (ft) EGL (ft) (Sta, El, n)-(Sta, El, n)... ( 0.00, 5423.92)-(596.58. 5418.92. 0.070)-(1346.58. 5418.92. 0.070)-(1661.50. 5419.31. 0.070) Elev (ft) 5424.00 5423.00 5422.00 5421.00 5420.00 5419.00 5418.00 5417.00 -100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 Section Friday. Sep 27 2019 = 0.16 = 100.00 = 132.00 = 0.76 = 898.39 = 0.09 = 898.39 = 0.17 N7 Depth (ft) 5.08 4.08 3.08 2.08 1.08 0.08 -0.92 -1.92 Sta (ft) Riprap Sizing Calculations Project No. 19021 Bayou Compressor Station Final Drainage Report RIRAP SIZING CALCULATIONS -REFERENCE URBAN DRAINAGE CRITERIA MANUAL (VOL. 2) CHAPTER 9, SECTIONS 3.2.1 RIPRAP APRON & 3.2.2 LOW TAILWATER BASIN STORM 1 (STM1) [PARTIAL BASIN OS31 - RIPRAP PAD Expansion Factor: Extent of Protection: Diameter (ft): Tailwater Depth (ft): Total Design Flow (cfs): 2.00 1.64 12.7 Yl/D: 0.82 Froude Parameter - Circular: Expansion Factor (From UDFCD Fig 9-35): Non -Eroding Velocity (ft/s): Computed Length of Protection (ft): Min. Length of Protection (30) (ft): Max Length of Protection (100) (ft): 2.25 Q/D2 5 6.70 5.0 -3.0 6.0 20.0 Equations 9-11 & 9-12 Expansion Angle: 0.074 Equation 9-13 Calculated Min. Width of Protection (ft): 1.55 Equation 9-14 Proposed Min. Riprap Apron Dimensions 811,4/x101 (From End of Flared End Section): Rock Sizing (UDFCD Fig 9-38): Total Design Flow (cfs): 12.7 Q/(D15): 4.49 Yt/D: 0.82 Riprap Type: TYPE L STORM 2 (STM2) [PARTIAL BASIN O53] - RIPRAP PAD Expansion Factor: Extent of Protection: Diameter (ft): Tailwater Depth (ft): Total Design Flow (cfs): 2.00 1.64 12.7 0.82 Froude Parameter - Circular: 2.25 Q/D2 5 Expansion Factor (From UDFCD Fig 9-35): 6.70 Non -Eroding Velocity (ft/s): Computed Length of Protection (ft): Min. Length of Protection (3D) (ft): Max Length of Protection (100) (ft): 5.0 -3.0 6.0 20.0 Expansion Angle: 0.074 Calculated Min. Width of Protection (ft): 1.55 Proposed Min. Riprap Apron Dimensions 811A/x101 (From End of Flared End Section): Rock Sizing (UDFCD Fig 9-38): Total Design Flow (cfs): 12.7 Q/(D15): 4.49 Yt/D: 0.82 Riprap Type: TYPE L Equations 9-11 & 9-12 Equation 9-13 Equation 9-14 09/27/2019 12:07 PM Crestone Consultants, LLC Page 1 of 2 Project No. 19021 Bayou Compressor Station Final Drainage Report RIRAP SIZING CALCULATIONS -REFERENCE URBAN DRAINAGE CRITERIA MANUAL (VOL. 2) CHAPTER 9, SECTIONS 3.2.1 RIPRAP APRON & 3.2.2 LOW TAILWATER BASIN DETENTION POND (BASINS D1 -D3) OUTFALL PIPE - LOW TAILWATER BASIN Diameter (ft): 1.00 Tailwater Depth (ft): 0.87 Total Design Flow (cfs): 2.90 Velocity (fps): 4.72 Q/D15: 2.90 Yt/D: 0.87 (1) From UDFCD Fig 9-37 (Low Tailwater Riprap Basin): (1) - Pond outfall pipe size is smaller than the pipe sizes listed on UDFCD Fig 9-37. Therefore, the low tailwater basin dimensions for the smallest pipe size (18" - 24") have been used, unless otherwise noted. Basin Depth - D (ft): Basin Width - W (ft): (1J Basin Length - L (ft): 1.0 4.0 12.0 (2) - Per UDFCD Fig 9-38 Type L riprap should be used for a distance of 3D downstream of the culvert. Therefore, a low tailwater riprap basin is not needed. However, the basin length - L has been set to making the dimensions as indicated on UDFCD Fig 9-37 work. Proposed Min. Riprap Apron Dimensions 10'Wx12'L (From End of Headwall/Wingwall): Equivalent Conduit Calculations: Design Flow (cfs): Froude Parameter - Circular: Culvert Diamater (ft): Froude Parameter - Circular: 2.9 2.90 Q/D2' 1.00 2.90 Q/D15 Rock Sizing - From UDFCD Fig 9-38 (Riprap Erosion Protection at Circular Conduit Outlet - valid for Q/D <= 6.0): Total Design Flow (cfs): 2.90 Q/D1': 2.90 Yt/D: 0.87 Riprap Type: TYPE L 09/27/2019 12:07 PM Crestone Consultants, LLC Page 2 of 2 Detention Pond Sizing Calculations Project No. 19021 Bayou Compressor Station Final Drainage Report DETENTION POND D1 - WATER QUALITY CAPTURE VOLUME (WQCV) CALCULATIONS BASIN Dli -REFERENCE UDFCD DRAINAGE CRITERIA MANUAL VOL. 3 - CHAPTER 3 Water Quality Capture Volume = WQCV = a*(0.91i 3-1.19i `+0.78i) (watershed inches) i = Total Imperviousness Ratio = Iwo/100 a = 40 -hr Drain Time = 1.0 BASIN DESIGN POINT IMPERVIOUSNES PERCENT S, I wq percent) IMPERVIOUSNESS RATIO, i WATER QUALITY CAPTURE VOLUME, WQCV (watershed inches D1 1 50.0 0.50 0.21 -REFERENCE UDFCD DRAINAGE CRITERIA MANUAL VOL. 3 - CHAPTER 3 Required Storage = [WQCV/12]*A*1.2 (acre -ft) A = Tributary Catchments Area (acres) 1.2 Factor = Multiplier to account for 20% sediment accumulation BASIN DESIGN POINT TRIBUTARY AREA, A* (acres) REQUIRED WATER QUALITY STORAGE (acre -ft) REQUIRED QUALITY STORAGE (it3 WATER D1 1 8.98 0.19 8,069 09272019 7:05 AM Crestone Consultants, LLC Page 1 of 1 i a. D g T n o c- o 3 g O ( a mss ro w z, o at zc O!r� cQ w mPa m u N Ell D o N V 2 N O O ai O 5 N CO m M te a a A t 0 'o N N O O d Y a w w w o c L • n w n n L ^ a n 7i a tl N O O t100 O sea I 570 I 11/n� 0 b CA o 540 I Iln.1 o I 520 + O 0 O I 490 0♦tl 000 a ♦0 I 450 I o W 0 I 420 I 00000000 O b O V {4w1 a N 0 330 1 W+ N 000 W 0 I 290 N 0 000 N 0 N 0 I 250 I N ♦ 00000000000 N W N 1�J N- 0 0 •• 0 + 0 0 ta •• ♦ I 130 +++ N- 0000000000 O 0 a V a Y♦ 0 O b 0 O �j Q i �SuN NN��jj O O && yT D O N 0 o G C 0 O V A25 y T D O UI 0 0` C L n N + N S g o w 1 0 o E A [�] c Cl N 0 ~ X§ f o x$ A o 5 Y +_ 0 n : n 11 o 0 D 0 lO 0 �- ma D C 2 0 En 3 p - Cl C n n n gn 0 0 w ' F Ij $ 3 3 di p n ^ non II 11 11 w a .J Eli 6 T g _ - • g1 . n o L-4-4mT0 n n0 $ SS w Fggqq� w n j 0 - 1 t f{ (' q •aj ^ Qq O O K n 3 E A Q gZZ 3� ES $ 3 0 3 '� Ni M li n lane N y 9 0 .-'i ti e D - II u 1• 11 •I II •II 5i 3 O 7 N Determination of MINOR Detention Volume Using Modified FAA Method 0000000000000000 0 01 on V V V O m W m 0 0++ N N 0.33 0.33 009090000090000009099090900 a♦ y(ay1 y y N y 1d O• V L I O W O- N 0 In Of V 0 0 N♦ 1/nI flail v p O N a m O 0 74 00000+a, 0000—a 0 N V flail 100 OV V010009100 0 0 N N 0 N OVI W tl+ O!lei S I<. Enter Randall Duraton Incremental Increase Value Here te.g 5 for 5-IArnrtesj W - 33.076 yy� •N 0 N N •Np O y41 •N N 0o 32.424 I N S 32.149 I N S fppjppl 0 W 0 W+ N+ QNr+1 b i •+. yy O N yf•il p O O O Al 5 yy O llOn Wy1 O 4$ yy p O 11�y1 101 W m a NI�1 y O• x yp O11 --• 1lyd m Y 0 O Nip) N a O a a- ONO V a 27,617 try a- V I�1 OI 0 I� a O• 1� W �/N1/0pI N 00 O N y in s- a s a• p W 0 1 23.432 N as N- N U. N. a I 20.743 yO %• y [ 18,323 V a 11Ip�A 10 J + A � OI O o O ^G q p< 22�{{ i t- J� s 0 U 0 N 0 a + 0 j 0 fn 0 N 0 N N 0 M N 0 N N 0.52 I 0 0 N 0 M N 0 M N 0 M N 0 N N 0 in N 0 M N 0 M N 0 M N 0 M Al 0 M N 0 M N 0 {n N 0 to N 0 0 Al o 0 N 0 N N 0 M N 0 0 W 0 M W 0 M W 0 M WNW 0 VI 0 M 0 M W 0 M W 0 to W 0 111 aa. 0 0 0 0 0.54 -I 1 57 I o 0 o N o 0 0 N o N o W o W o 0 0 0 o 0 o 0 o O o N♦ 0 o W o v o v 0- 0 S a gg '1 'p S ` B y 0, 1 49 I 53627 I 1 49 f 52 757 1.49 I 48,407 I 1.49 1 47.537 {{/n� 0 0 0 0 0 150 _ _.I 42.317 1.50 I 41.447 1.50 I 40.577 1.50 I 39,707 lO lO lO /O lO In In 1 52 I 32 747 N N 1 52 1 30.137 N W V 1.53 I 26.657 u 1.54 1 24,917 I 1.54 I 24, 047 N 1 55 1 22.307 1.55 1 21.437 yN1 OI y1 O 158 1 17.957 1f1n� a 0 pq• o 1.81 I 14,477 5W0-00 o a -.00 V 1.85 I 6.647 — y N a N a VI i mg 0 pOp 0 a w 0 b i NON 0 -.9 N V + a _ 0 a �0 S 0 0 N Y J �/1 O aN V m V OgmpO11 ^l ul V ♦ V ♦ V w CO a J /1QVppJ1 V V V yI �Oy��JJi V VI V �' V u V '.+1 8+ V 1� 10 AI V a fa V V 0 V (I' V u1 V po� 1l001 V m J a V �l OS a m V i(♦n� V w V M V - 0V o V N0 V 0 V °i V `1 '^ V �1Op' V ♦ V u J " a O {4? yCC� 4 < �nT `� flgii AAA 11 w r,, -'. O o N U N i e. o O -20 426 • 0 a+ • O V • O • y{ V1 OI • 01 P • to fad • fn 0 • ♦ a • W v • W N , N V Ol a 001 o 0V m S b N y V Y b Na N y N• a I. 0 W 4Vn W 40 up N++ a CO a .Vi fJ' - 0 1.434 I N O N O W N w ca O+♦ N In 0 0 pG t.• V 0 V a a 0 Y0 0 W 0-+ lla 0 0- m l+ +-++-++ S 0 N OVi V L46' 0 `' OOI•I ` 0 _ �p[5J < or y 8 4 3 v SS S 0000 1 530 f 0 0$ o [ 09► 00000000000 S g o g g o g o0 0 000 0 I 240 I /NS11NN L 210 g S S o S o o bd o o S S o 0 0 0 0 l� o 0 0 R l Determination of Average Outflow from the Basin (Calculatedl, Runoff Coefficient C = 0.52 Inflow Peak Runoff Qp.n = 24.6 cfs Movable Peak Outflow Rate Op -cut = 2.9 cfs Mod. FAA Major Storage Volume = 39,071 cubic feet Mod. FM Major Storage Volume = 0.90 acre -ft Coen cent One C,= 28.50 Coef.aent Two C2 = 10 Coefficient Three C3= 0.789 A$owabte tM Release Rate q = One•nour Preceptor P. Design RaM llIDF Formula I - C,' P,1(CirTJ•C, 0• Oho 3 9 V 9 = g1 ono„D KS SDia4 wawdopwapaid sane 96-9 = V Italy a80uaip tuawµtoeo luaarad 0OS =') ssausnovuadwl a8euup:Jauuax:, pnaull uoueuuojul ubisap Determination of MAJOR Detention Volume Using Modified FAA Method 0 w 0 44015 0 0 0 0 V 0 b 0 m 0 b 0 0 0 l+ 0 N 0 unit 0 i 0 1 0 Iln!• no 0 V 0 0 0 0 MO +1 N 0 {ail m 0m a 0 W 0 V 0 O 0 O 0 N 0 0 0Vi 0 a 0 O 0 N 0 0 V 0 in 0 N 0 S 0+-• N a V+ •- a i+ + V♦♦ {- - + + 0 - 0 - - (aJ• N O N O I 244 NNW OVi 0 0 a V 1 6.57 oII 8 A 'i M g t T L 74 468 I a • 0 V W V Y A V W i V Y V V N g 72.420 V N+ m V a 71.473 [ -. 0 V O a 70,476 -i V O N' a m a 0 : 0 00 g 0 0 W a 0 O 0 V U CO V O: 0 V Oli O -+V• S g a N a (n -40I �1 I 64,489 a W u fN'J. u C I 62,484 I 61.944 a+ g 47. b+ 0 m in 0 V a o V o 01 a 01 o I 55,269 v V a 1 52,557 + a O s .a♦O vN'I J 1 48,525 0 I 43,152 a 0 'J .tW1• a _ 31 955 a - 1 18.405 O r. C < 78$I ff11 Qfiy. p` am 000000000090000000000000000 l0 /n 10 f0 f0 + N N N N N N N N N N N N N N N N N N N N N 0.52 0000000000000000000000000000000a0 Y a a W tln•J a Ilnd a W♦ a a tt0!• 0 Tn 0 0 OI V V 0 0 I 0.60 _ I 1.75 I N♦ 01 + a+ 0 p 0 Adjustment Average Factor Oudlow cfs (SC toutPutl 1.49 } 53.627 1.49 52.757 A♦♦♦ 0 0 0 0 1. 0 a 0 0 0 1.50 1 45 797 1.50 I 44927 1.50 I 44.057 1 0 0 1.50 1 42.317 I 1.50 I 41 447 1.50 40.577 to 0 M M M M 0 M to 1.52 I 32.747 I a Al N Al N N M N 0 W N W to W WI W♦♦ Y 1 54 I 24,047 0 to 1.55 1 22,307 N fn P W {{ln1 of VI V N a N a N 0 0 0- 181 I 14.477 1,62 I 13.607 0 a a {n C! V m 0 1.71 I 9,257 V CO CN a 0 W♦♦ b 2.24 I 4,037 N a. MO 0 0 O 0 N N W W♦ O 0 U t`3 M 0 O V ♦♦♦♦ . CO11 V a V f{-{(d4n V pp0pp1111 V ♦ W V W 0 J Y 0 J Y ((-4p1 V W (po-J v y ANO1l v W IJ v y a a W Ca ++ V O W O V NA) 0 O a m Al V N N 0 fa/ N O• a N ♦ 0+ N W J N V Al py0(On�11 V 0 V yl0 0a V V V V b a v 0 -� N V Ooo+11 J -+ O m O V 0 V v V 0 00♦♦ V .�11 V �O�p♦pp V V V a O Q j E IS w R M YY1I VVVV xx14 w O N N 2 0 O +• N - N N V Le N 0 5 W11 V N y{ W1 0 5 •♦ 0 N W NNN In W �1y11pppp V 0 COco N V N V V N a 03 N a Yal N 1pp0 ♦ N �O V y1 O Gs o O N W • W W p+ 01 32.171 32 637 1 41441,4 fpWp a+ y♦ W W a♦ Ip� y ♦ 0 4444 Ur N UI N tlI COa y OI N + td P N W V N 37.339 I 37,632 Y V tin Y a 1100 y b S 41 a 0 y P m W pO O V W a 0 W 0 N Y a I 39,039 1 W C f+ I 38,797 1 W a V W a COlCa Y V W V a 41 vi UV W W VI IYn y • 0 I 32 900 1 $ O N N V a N Oy Y1• 01 p0 1 Ol 0 ppp p T w fill O _m Z O n � d m Z-34. O n Y N n 7 N N • Y 7 + 01 • Oa T n 40 7 U. co 0 0 H CON a „ O 7 C_'fi 7 O f0 1O d y Ct tl 7 CO CO o • r St LA A 7 a O a 1.0 utseg Of uisee ee :230101d O C Ca) 0 3 U011PIS JOS50J It C N D n 0 A a w u a A 0 0 a O m -i m z O z O r C Ph m C 2 8 T O D O O I Ms 19071 DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Project: Bayou Compressor Station Basin D: Basin D1 r Inflow and Outflow Volumes vs. Rainfall Duration Volume (Cubic Feet) 80.000 60,000 40,000 20,000 0 -20,000 -40,000 • .•••.. • • ....4.— . 100 210 300 440 500 600 7i Duration (Minutes) —a--....Ina ..►..._ -Sa_.•••• — 1... ._..i. ._... —.r r..._..._ -_.r _._I_+.... 0 UDFCD DETENTION VOLUME ESTIMATING WORKBOOK Version 2.2. Released January 2010 J Geeslin Consultant", LIZ Project No 19021 Bayou Compressor Station Final Drainage Report DETENTION POND VOLUME CALCULATIONS [BASIN Dl] (1)Required WQCV = 0.19 ac -ft 100 Yr Detention Req'd Volume = 0.90 ac -ft From WQCV Calculations From UDFCD Modified FAA Method Calculation it) Per Weld County Code, WQCV included as a portion of the total 100 Yr required detention volume. POND VOLUME = 1/3(A1+A2+(Al*A2)^0.5)*D DETENTION POND INCREM VOLUME CUMM. VOLUME CUMM. VOLUME ELEV AREA (ft') (ft3) (ft3) (ac -ft) (1) 100 Yr Volume 5412.00 0 0 0 0.00 WQCV 5413.00 14,903 4,968 4,968 0.11 5413.11 8,069 0.19 Freeboard 5414.00 42,579 27,557 32,525 0.75 5414.13 39,071 0.90 Freeboard 5415.00 63,992 52,923 85,448 1.96 5416.00 92,947 78,020 163,469 3.75 Pond volumes based on Prismoidal Method calculations DETENTION POND DRAIN TIME CALCULATIONS [BASIN Dli Drain Time Calculation via Infiltration: 100 Yr Detention Req'd Volume = 0.90 ac -ft From UDFCD Modified FAA Method Calculation Depth to 100 YR Water Surface to WQCV Water Surface = 1.02 ft Infiltration Rate = 0 min/in Time to Drain = 0 hours Drain Time Calculation via Average 100 Yr Release Rate: 100 Yr Detention Req'd Volume = 0.90 ac -ft 100 Yr Detention Req'd Volume = 39,071 ft3 100 Yr Detention Req'd Volume less WQCV = 31,002 ac -ft 100 Yr Allowable Release Rate = 2.90 cfs Average 100 Yr Release Rate = 1.45 cfs Time to Drain 100 Yr Detention to WQCV Water Surface = Time to Drain WQCV = Total Time to Drain 100 Yr Storm = 5.9 hours 40.0 hours 45.9 hours 09/27/2019 7 09 AM No infiltration assumed From UDFCD Modified FAA Method Calculation Non -Urbanizing Area, therefore max allowable release = Historic Q10 1/2 of 100 Yr allowable release rate Drain time less than 120 hours - OK Crestone Consultants, LLC Page 1 of 1 Job No. 19021 Bayou Compressor Station Final Drainage Report DETENTION POND OUTLET STRUCTURE BOX SIZING [BASIN D1) Orifice Equation- Area=Q, / (0.65 * (2 * g * h)2)) Q, = Allowable release rate [cfs] g = 32.2 (ft2/s] h = Difference from water surface elevation to top of grate elevation [ft] WATER SURFACE *TOP OF GRATE 100-YR W.S. ELEV Qr loo (cfs) HEAD at Qr (ft) AREA REQ'D (ft2 Release 5413.90 5414.13 2.9 0.23 1.16 *Top of box grate elevation is above WQCV Water Surface Elevation Weir Equation- Q,=C*L*h312 Q. = Allowable release rate [cfs] c = Weir Coefficient, 3.33 used L = Length of Weir [ft] h = Difference from water surface elevation to top of grate elevation [ft] WATER SURFACE *TOP OF GRATE 100-YR W.S. ELEV Qr loo (cfs) HEAD at Qr (ft) LENGTH REQ'D (ft) Release 5413.90 5414.13 2.9 0.23 7.90 *Top of box grate elevation is above WQCV Water Surface Elevation Outlet Structure Box - Try CDOT Type C Inlet Box Length = 2.92 ft Width = 2.92 ft Acr = 8.53 ft2 x 50% Clogging Factor = 4.27 ft2 Orifice Check- = 1.16 ft2, Aopo,. = 4.27 ft:, therefore OK, CDOT Type C Inlet Box OK Weir Check- = 7.90 ft, L = 4*2.92 = 11.68 ft2, therefore, CDOT Type C Inlet Box OK 09/27/2019 8:18AM Crestone Consultants, LLC Page 1 of 1 "roint Nu 194'21 i _ STAGE -DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET i Project: Bayou Compressor Station Basin ID: Basin D1 WQCV Da lion Volume llnout): Catchment Imperviousness, Ia = Catchment Area, A = Depth at WQCV outlet above lowest perforation. H Vertical distance between rows, h = Number of rows, NI. Orifice discharge coefficient. Co a Outlet Damian Information (Output); 50.0 8.98 12 4.00 percent acres inches inches 3 0.65 Diameter of toles, D = Number of holes per row, N = Height of slot. H Width of slot. W Water Quaky Capture Volume (1.0 ' (0.91 • l"3. 1.19 • I"2 + 0.78' 1)), WQCV = Water Quaky Capture Volume (WQCV) = Design Volume (WQCV / 12 • Area 1.2) Vol Recommended maximum outlet area per row (based on 4" vertical spacing of rows), A0 Total opening area at each row based on user -input above, A0 = Total opening area at each row based on user -input above, A0 = Cakulation of Collection Capacity', Pa 1.00 2.3125 in in. in. Time to Drain the Pond = 40 hours Water Quality Capture Volume Method Selected (40 Hour Release) 0.21 watershed inches 0.15 acre-feet 0.19 acre-feet 2.321 square inches 2.313 square Inches 0.016 square feet 0 O O 0 O o 0 O r► I 0 0 O O O O 0 0 O 0 O O O O o O O 0 O O O O o O O ° O O O O O 0 O _ 0 0 t1 ti 0 o (= 0 O I 0 Perforated Plate Framples Stage ft (input) Central Elevations of Rows of Holes m feet Row 1 Row 2 Row 3 Row 4 Row 5 Row 6 Row 7 Row 8 Row 9 Row 10 Row 11 Row 12 Row 13 Row 14 Row 15 Row 16 Row 17 Row 18 E 5412.11 15412.44 15412.78 I Flow Collection Capacity for Each Row of Holes in cis 5412.11 0.000 0.000 0.000 0.00 5412.44 0.048 0.000 0.000 0.05 5412.77 0.068 0.048 0.000 0.12 5413.11 0.084 0.069 0.048 0.20 5413.90 0.112 0.101 0.089 0.30 5414.13 0.119 0.109 0.097 0.33 5415.00 0.142 0.134 0.125 0.40 *NIA ANd/A #N/A #N/A #N/A ANJ/A *N/A #WA #N/A #N/A *N/A #N/A #WA #N/A *NIA #N/A *N/A ON/A *NIA #WA ANV/A #WA #N/A #WA *NIA #N/A ANJ/A #N/A ANJ/A ANH/A #N/A MIA #N/A *N/A AtN/A #WA Ithl/A #N/A #N/A #WA ANJ/A #N/A ANJ/A #WA *N/A #NIA ANJ/A #N/A ftN/A #N/A Ets1/A #N/A #N/A fiti/A IOWA #N/A SN/A AN /A *NIA #WA #N/A #N/A #WA Whl/A *N/A ANd/A *NIA #N/A #WA #N/A *NIA #N/A #N/A ltN/A #WA "NIA #N/A *NIA ON/A #WA ANJ/A #N/A #N/A #N/A #N/A *NIA MIA UN/A #N/A ANJ/A #N/A #N/A #N/A ANd/A #N/A IIN/A *NIA *NIA #WA ON/A *N/A *N/A #WA #N/A *N/A ON/A *WA MIA *N/A *NIA ANJ/A #N/A #WA #WA #N/A #WA *NIA #N/A #N/A ltN/A #WA *NIA #NIA #WA *N/A ON/A MIA #WA ANJ/A #N/A ON/A #N/A ANJ/A #N/A ANJ/A ON/A SN/A *NIA UN/A #WA ANJ/A *N/A #N/A #N/A MIA #N/A ANJ/A #N/A 09/17/2016 642 MA C/aaron. Consultants. LLC Papa I 0/ 2 Prole° No 19021 STAGE -DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET Project: Bayou Compressor Station Basin ID: Basin D1 STAGE -DISCHARGE CURVE FOR THE WQCV OUTLET STRUCTURE (1085.50 5085.50 4085 50 ,'085.50 2085.50 1085.50 85.50 0.00 0.05 0.10 0.15 020 0.25 Discharge (cfs) 0.30 0.35 0 40 0.4`_) Weir Report Hydraflow Express Extension for Autodesk® AutoCADD'F' Civit 3a<) by Autodesk, Inc Basin D1 - Pond Outlet Structure Weir (Qrelease=2.9 cfs) Rectangular Weir Crest Bottom Length (ft) Total Depth (ft) Calculations Weir Coeff. Cw Compute by: Known Depth (ft) = Sharp = 1.25 = 0.79 = 3.33 Known Depth = 0.79 Highlighted Depth (ft) Q (cfs) Area (sqft) Velocity (ft/s) Top Width (ft) Friday, Sep 27 2019 = 0.79 = 2.923 = 0.99 = 2.96 = 1.25 'Calculation to determine box weir size to pass Qrelease of 2.9 cfs (100 yr release) through box above the WQWS El, since top of box is above the WOWS El. 100 yr release from the pond is controlled via a restrictor plate located on the pond outfall pipe Depth (ft) 1.00 0.50 0.00 -0.50 Basin D1 - Pond Outlet Structure Weir (Qrelease=2.9 cfs) I Top of Box El = 5413.90 V WQWSEI=5413.11 0 Weir 5 W.S. 1 1.5 2 2.5 Depth (ft) 1.00 0.50 0 00 -0.50 Length (ft) Project No 19021 RESTRICTOR PLATE SIZING FOR CIRCULAR VERTICAL ORIFICES Project: Bayou Compressor Station Basin ID: Basin D1 x Sizing the Restrictor Plate for Circular Vertical Orifices or Pipes (Inputl Water Surface Elevation at Design Depth PipeNertical Orifice Entrance Invert Elevation Required Peak Flow through Orifice at Design Depth PipeNertical Orifice Diameter (inches) Orifice Coefficient Full -flow Capacity (Calculated) Full -flow area Half Central Angle in Radians Full -flow capacity Calculation of Orifice Flow Condition Half Central Angle (0<Theta<3.1416) Flow area Top width of Orifice (inches) Height from Invert of Orifice to Bottom of Plate (feet) Elevation of Bottom of Plate Resultant Peak Flow Through Orifice at Design Depth Elev: WS = Elev: Invert = Q= Dia = _ Af = Theta = Qf = Percent of Design Flow = Theta = A„= T„ = Yo = Elev Plate Bottom Edge = Q„ = Width of Equivalent Rectangular Vertical Orifice Equivalent Width = Centroid Elevation of Equivalent Rectangular Vertical Orifice Equiv. Centroid El. = #1 Vertical Orifice #2 Vertical Orifice 5,414.13 5,414.13 5,411.82 5,411.82 2.9 2.9 12.0 12.0 0.65 0.65 0.79 0.79 3.14 3.14 5.5 5.5 190% 190% 1.56 0.10 0.39 0.39 12.00 12.00 0.49 0.49 5,412.31 5,412.31 2.9 2.9 0.80 0.80 5Al2.07 5.412.07 feet feet cfs inches sq ft rad cfs rad sq ft inches feet feet cfs feet feet 09/27/2019 828 AM Crestone Consultants, LLC Page 1 of 1 Culvert Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk. Inc. Basin D1 - Pond Outlet Pipe (Qrelease=2.9 cfs) Invert Elev Dn (ft) Pipe Length (ft) Slope (%) Invert Elev Up (ft) Rise (in) Shape Span (in) No. Barrels n -Value Culvert Type Culvert Entrance Coeff. K, M . c. Y. k Embankment Top Elevation (ft) Top Width (ft) Crest Width (ft) Bev (Rt 541600 541500 541400 541300 5412 00 5411 00 541000 = 5411.39 = 43.30 = 0.99 = 5411.82 = 12.0 = Circular = 12.0 = 1 = 0.013 = Circular Concrete = Square edge w/headwall (C) = 0.0098. 2. 0.0398. 0.67. 0.5 = 5415.00 = 18.00 = 26.00 Basin D1 - Pond Outlet Pipe (Qrelease-2.9 cfs) Calculations Qmin (cfs) Qmax (cfs) Tailwater Elev (ft) Highlighted Qtotal (cfs) Qpipe (cfs) Qovertop (cfs) Veloc Dn (ft/s) Veloc Up (ft/s) HGL Dn (ft) HGL Up (ft) Hw Elev (ft) Hw/D (ft) Flow Regime Friday. Sep 27 2019 = 2.90 = 2.90 = (dc+D)/2 = 2.90 = 2.90 = 0.00 = 4.02 = 4.72 = 5412.26 = 5412.55 = 5413.03 = 1.21 = Inlet Control HM Depth it 0 5 10 Circular C iver1 15 20 HGL 25 30 Embank 35 10 46 50 56 50 65 Reach oft) 4.16 3 /8 2 18 1 18 0 18 •082 • 1 82 Weir Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Basin D1 - Pond Em Overflow (Q100=24.4 cfs) Trapezoidal Weir Crest Bottom Length (ft) Total Depth (ft) Side Slope (z:1) Calculations Weir Coeff. Cw Compute by: Known Q (cfs) Depth (ft) 2.00 1.50 1.00 0.50 = Sharp = 26.00 = 1.00 = 4.00 = 3.10 Known Q = 24.40 Highlighted Depth (ft) Q (cfs) Area (sqft) Velocity (ft/s) Top Width (ft) Basin D1 - Pond Em Overflow (Q100=24.4 cfs) Friday. Sep 27 2019 = 0.44 = 24.40 = 12.21 = 2.00 = 29.52 000 - -0.50 410 • 0 5 Weir 10 15 W.S. 20 25 30 35 40 45 Depth (ft) 2.00 1.50 1.00 0.50 0.00 0.50 Length (ft) Hydraulic Calculation Reference Materials Chapter 8 Open Channels Table 8-5. Recommended roughness values Location and Cover When Assessing Velocity, Froude No., Shear Stress When Assessing Water Surface Elevation and Water Depth Main Channel (bankfull channel) Sand or clay bed 0.03 0.04 Gravel or cobble bed 0.035 0.07 Vegetated Overbanks Turfgrass sod 0.03 0.04 Native grasses 0.032 0.05 Herbaceous wetlands (few or no willows) 0.06 0.12 Willow stands, woody shrubs 0.07 0.16 (Source: Chow 1959, USDA 1954, Barnes 1967, Arcement and Schneider 1989, Jarrett 1985) Roughness of Grass Overbanks A common procedure for determining Manning's n for vegetated channels is documented in the Handbook of Channel Design for Soil and Water Conservation (hereinafter referred to as the NRCS Method). The NRCS Method uses the vegetation properties to establish a degree of retardance. The retardance is based upon the type of plants, the length and condition of the vegetation. Finding a solution for Manning's n becomes an iterative process using the following channel properties: slope, velocity and hydraulic radius. The documentation for the NRCS method contains a series of curves that provide solutions for Manning's n values based upon the vegetation retardance. Table 8-6 provides recommended retardance values for channels located along the Colorado Front Range with the given vegetation properties. Refer to the NRCS Method documentation for additional detail and guidance. January 2016 Urban Drainage and Flood Control District 8-61 Urban Storm Drainage Criteria Manual Volume 1 Hydraulic Structures Chapter 9 3.2.1 Riprap Apron This section addresses the use of riprap for erosion protection downstream of conduit and culvert outlets. Refer to the Open Channels chapter for additional information on applications for and placement of riprap. Those criteria will be useful in design of erosion protection for conduit outlets. When incorporating a drop into the outfall use Figure 9-40 or 9-41. Rock Size The procedure for determining the required riprap size downstream of a conduit outlet is in Section 3.2.3. Configuration of Riprap Apron Figure 9-34 illustrates typical riprap protection of culverts at conduit outlets. Extent of Protection The length of the riprap protection downstream from the outlet depends on the degree of protection desired. If it is necessary to prevent all erosion, the riprap must extend until the velocity decreases to an acceptable value. The acceptable major event velocity is set at 5 ft/sec for non -cohesive soils and at 7 ft/sec for erosion resistant soils. The rate at which the velocity of a jet from a conduit outlet decreases is not well known. The procedure recommended here assumes the rate of decrease in velocity is related to the angle of lateral expansion, 0, of the jet. The velocity is related to the expansion factor, (l /(2tan0)), which can be determined directly using Figure 9-35 or Figure 9-36, by assuming that the expanding jet has a rectangular shape: L = I A` 2tan0 Y, Where: = length of protection (ft) W = width of the conduit (ft, use diameter for circular conduits) Y, = tailwater depth (ft) 0 = the expansion angle of the culvert flow and: A, Q V Where: Q = design discharge (cfs) V = the allowable non -eroding velocity in the downstream channel (ft/sec) A, = required area of flow at allowable velocity (ft2) Equation 9-11 Equation 9-12 9-66 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 2 September 2017 Chapter 9 1 lydraulic Structures In certain circumstances, Equation 9-11 may yield unreasonable results. Therefore, in no case should Lp be less than 3H or 3D, nor does Lp need to be greater than 10H or 10D whenever the Froude parameter, Q/WH1.5 or Q /02.5, is less than 8.0 or 6.0, respectively. Whenever the Froude parameter is greater than these maximums, uincrease the maximum Lp required by 'A DC or 'A H for circular or rectangular (box) culverts, respectively, for each whole number by which the Froude parameter is greater than 8.0 or 6.0, respectively. Once Lp has been determined, the width of the riprap protection at the furthest downstream point should be verified. This dimension is labeled "T" on Figure 9-34. The first step is to solve for 0 using the results from Figure 9-35 or 9-36: e = tan -I 1 2(ExpansionFactor) Where: Expansion Factor = determined using Figure 9-35 or 9-36 T is then calculated using the following equation: T = 2(Lo tan B)+ W Equation 9-13 Equation 9-14 Multiple Conduit Installations The procedures outlined in this section can be used to design outlet erosion protection for multi -barrel culvert installations by replacing the multiple barrels with a single hydraulically equivalent hypothetical rectangular conduit. The dimensions of the equivalent conduit may be established as follows: 1. Distribute the total discharge, Q, among the individual conduits. Where all the conduits are hydraulically similar and identically situated, the flow can be assumed to be equally distributed; otherwise, the flow through each barrel must be computed. 2. Compute the Froude parameter Wag" (circular conduit) or Q,/TH,1.5 (rectangular conduit). where the subscript i indicates the discharge and dimensions associated with an individual conduit. 3. If the installation includes dissimilar conduits, select the conduit with the largest value of the Froude parameter to determine the dimensions of the equivalent conduit. 4. Make the height of the equivalent conduit, /1„,,, equal to the height, or diameter, of the selected individual conduit. 5. The width of the equivalent conduit, Weq, is determined by equating the Froude parameter from the selected individual conduit with the Froude parameter associated with the equivalent conduit, Q/WsHe4' '• September 2017 Urban Drainage and Flood Control District 9-67 Urban Storm Drainage Criteria Manual Volume 2 Hydraulic Structures Chapter 9 EXTEND RIPRAP TO HEIGHT OF PIPE OR BOX, MIN. 05 RIPRAP MORE THAN 1.0' ABOVE PIPE INVERT SHALL BE INSTALLED 6' BELOW FINISHED GRADE AND BURIED WITH TOPSOIL JOINT RESTRAINTS (2) FINISHED GRADE PLAN VIEW NTS END TREATMENT MAY CONSIST OF RCP END SECTION (WITH TOEWALL) OR HEADWALL. (SEE DETAILS) L 1 J 2Dy, MIN - PROFILE J SOIL RIPRAP OR VOID-ALLED RIPRAP 05 Figure 9-34. Riprap apron detail for culverts in -line with the channel 9-68 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 2 September 2017 Chapter 9 Hydraulic Structures 8 = Expansion Angle a_ 0 EXPANSION 8 7 6 5 4 2 1 0 i .2 .3 .4 5 .6 .7 .8 TAILWATER DEPTH/ CONDUIT HEIGHT, Yt/D / D h' ti �O /I h a 0 gi 0 O /r / / — ___ , ki O cF 0 / f /V Figure 9-35. Expansion factor for circular conduits September 2017 Urban Drainage and Flood Control District 9-69 Urban Storm Drainage Criteria Manual Volume 2 Hydraulic Structures Chapter 9 8 7 6 CD c O N5 oc 4 Li - 0 3 U) z Q x 2 W 1 0 $9 = Expansion Angle b f 1g 0 .1 .2 .3 .4 .5 .6 .7 .8 TAILWATER DEPTH/ CONDUIT HEIGHT—Yt/H Figure 9-36. Expansion factor for rectangular conduits .9 1.0 9-70 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 2 September 2017 Chapter- 9 Hydraulic Structures 3.2.2 Low Tailwater Basin The design of low tailwater riprap basins is necessary when the receiving channel may have little or no flow or tailwater at time when the pipe or culvert is in operation. Figure 9-37 provides a plan and profile view of a typical low tailwater riprap basin. By providing a low tailwater basin at the end of a storm drain conduit or culvert, the kinetic energy of the discharge dissipates under controlled conditions without causing scour at the channel bottom. Low tailwater is defined as being equal to or less than '/3 of the height of the storm drain, that is: D H y<<- y, 3 or 3 Where: y, = tailwater depth at design flow (feet) D = diameter of circular pipe (feet) H = height of rectangular pipe (feet) Rock Size The procedure for determining the required riprap size downstream of a conduit outlet is in Section 3.2.3. After selecting the riprap size, the minimum thickness of the riprap layer, T, in feet, in the basin is defined as: T =24, Equation 9-15 Basin Geometry Figure 9-37 includes a layout of a standard low tailwater riprap basin with the geometry parameters provided. The minimum length of the basin (L) and the width of the bottom of the basin (WI) are provided in a table at the bottom of Figure 9-37. All slopes in the low tailwater basin shall be 3(H):1(V), minimum. Other Design Requirements Extend riprap up the outlet embankment slope to the mid -pipe level, minimum. It is recommended that riprap that extends more than I foot above the outlet pipe invert be installed 6 inches below finished grade and buried with topsoil. Provide pipe end treatment in the form of a pipe headwall or a tlared-end section headwall. See Section 3.1 for options. September 2017 Urban Drainage and Flood Control District 9-71 Urban Storm Drainage Criteria Manual Volume 2 Hydraulic Structures Chapter 9 RIPRAP MORE THAN 1.0' ABOVE PIPE INVERT SHALL BE INSTALLED 6" BELOW FINISHED GRADE AND BURIED WITH TOPSOIL FINISHED GRADE 11 JOINT /1 - RESTRAINTS (2) RCP WITH FES SHOWN END TREATMENT MAY CONSIST OF PIPE HEADWALL OR FES HEADWALL FES HEADWAL L SHOWN PROF LE FINISHED GRADE SEE TABLE SOIL RIPRAP OR T=2Drao MIN VOID —FILLED RIPRAP PIPE SIZE OR D. iL• L BOX HEIGHT 18" — 24" W Nt N. I III I� o c, o a► o sass i 4' 15. 30" — 36" 6' 20' 42" — 48" 7 24' 5C — 60" 8' 28' 66" — 72" 9' 32' • IF OUTLET PIPE IS A BOX CULVERT WITH A WIDTH GREATER THAN W, THEN W = CULVERT WIDTH Figure 9-37. Low tailwater riprap basin 9-72 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 2 September 2017 Chapter 9 I l`draulic Structures 3.2.3 Rock Sizing for Riprap Apron and Low Tailwater Basin Scour resulting from highly turbulent, rapidly decelerating flow is a common problem at conduit outlets. The following section summarizes the method for sizing riprap protection for both riprap aprons (Section 3.2.1) and low tailwater basins (Section 3.2.2). Use Figure 9-38 to determine the required rock size for circular conduits and Figure 9-39 for rectangular conduits. Figure 9-38 is valid for Q/DD2 5 of 6.0 or less and Figure 9-39 is valid for Q/WH15 of 8.0 or less. The parameters in these two figures are: 1. Q/D'S or Q/WH05 in which Q is the design discharge in cfs, a is the diameter of a circular conduit in feet, and Wand H are the width and height of a rectangular conduit in feet. 2. Vila or Yp/H in which Y, is the tailwater depth in feet, DC is the diameter of a circular conduit in feet, and His the height of a rectangular conduit in feet. In cases where Y, is unknown or a hydraulic jump is suspected downstream of the outlet, use Y,/D, = Y,/H= 0.40 when using Figures 9-38 and 9-39. 3. The riprap size requirements in Figures 9-38 and 9-39 are based on the non -dimensional parametric Equations 9-16 and 9-17 (Steven, Simons, and Watts 1971 and Smith 1975). Circular culvert: 0.023Q d� = 2 0 3 Equation 9-16 Rectangular culvert: 0.014Ho.5Q clay = Y,W Equation 9-17 These rock size requirements assume that the flow in the culvert is subcritical. It is possible to use Equations 9-16 and 9-17 when the flow in the culvert is supercritical (and less than full) if the value of a or H is modified for use in Figures 9-38 and 9-39. Note that rock sizes referenced in these figures are defined in the Open Channels chapter. Whenever the flow is supercritical in the culvert, substitute D. for a and Ho for H, in which Do is defined as: D =--(DC +Y„) 2 Where the maximum value of Da shall not exceed D., and Equation 9-18 September 2017 Urban Drainage and Flood Control District 9-73 Urban Storm Drainage Criteria Manual Volume 2 Hydraulic Structures Chapter 9 H (H+Y„ _) a Equation 9-19 Where the maximum value of Hu shall not exceed H, and: • = parameter to use in place of D in Figure 9-38 when flow is supercritical (ft) D, = diameter of circular culvert (ft) • = parameter to use in place of H in Figure 9-39 when flow is supercritical (ft) H = height of rectangular culvert (ft) Y„ = normal depth of supercritical flow in the culvert (ft) in 0 0 60 40 if- . - - et Ngab C\ e � C , t bi TYPE L .2 .4 .6 Yt/D .8 Use Da instead of D whenever flow is supercritical in the barrel. **Use Type L for a distance of 3D downstream 1.0 Figure 9-38. Riprap erosion protection at circular conduit outlet (valid for Q/D2.5 5 6.0) 9-74 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 2 September 2017 Chapter 9 Hydraulic Structures 6O 0 40 v 20 A ceJ �4. �V� AV xx O` <, ,�yQ1 ��QE UU .2 .4 Yt/H .6 .8 1.0 Use Ha instead of H whenever culvert has supercritical flow in the barrel. **Use Type L for a distance of 3H downstream Figure 9-39. Riprap erosion protection at rectangular conduit outlet (valid for Q/WH1.5 S 8.0) 3.2.4 Outfalls and Rundowns A grouted boulder outfall or "rundown" dissipates energy and provides erosion control protection. Grouted boulder outfalls are most commonly used in large rivers like the South Platte. Figure 9-40 provides a plan view and cross section for a standard grouted boulder rundown. See the grouted boulder drop profiles (Al, A2, and A3) in Figure 9-12 for site specific profile options, (i.e., depressed or free - draining basin for use with a stable downstream channel or with no basin for use in channels subject to degradation). Figure 9-41 provides a plan view of the same structure for use when the structure is in -line with the channel. Evaluate the following when designing a grouted boulder outfall or rundown: • Minimize disturbance to channel bank • Determine water surface elevation in receiving channel for base flow and design storm(s) • Determine flow rate, velocity, depth, etc. of flow exiting the outfall pipe for the design storm(s) • Evaluate permitting procedures and requirements for construction adjacent to large river system. September 2017 Urban Drainage and Flood Control District 9-75 Urban Storm Drainage Criteria Manual Volume 2 EM 1110-2-1601 1 July 1991 US Army Corps of Engineers ENGINEERING AND DESIGN Hydraulic Design of Flood Control Channels ENGINEER MANUAL EM 1110-2-1601 Change 1 30 Jun 94 * attack in braided streams is thought to occur when the water surface is at or slightly above the tops of the mid - channel bars. At this stage, flow is confined to the multi- ple channels that often flow into or 'impinge" against bank lines or levees. At lesser flows, the depths and velocities in the multiple channels are decreased. At higher flows, the channel area increases drastically and streamlines are in a more downstream direction rather than into bank lines or levees. (b) The discharge that produces a (stage near the tops of the midchannel bars is Qtmcb • Qtmcb is probably highly correlated with the channel -forming discharge concept. In the case of the Snake River near Jackson, Wyoming, Qtmcb is 15,000-18,000 cfs, which has an average recurrence interval of about 2-5 years. Using cross-section data to determine the channel area below the tops of the midchannel bars and Qtmcb allows determina- tion of the average channel velocity at the top of the midchannel bars, V,m:b . (c) Field measurements at impingement sites were taken in 1991 on the Snake River near Jackson, Wyoming, and reported in Maynord (1993). The maxi- mum observed ratio Vss/Vtmcb = 1.6 , which is almost identical to the ratio shown in Plate 33 for sharp bend - ways having R/W = 2 in natural channels, and this ratio is recommended for determining Vss for impinged flow. The second area of the design procedure requiring modifi- cation for impinged flow is the velocity distribution coef- ficient Cv , which varies with R/W in bendways as shown in Plate 40. Impinged flow areas are poorly aligned bends having low R/W , and C,, = 1.25 is recommended for design. (6) Transitions in size or shape may also require riprap protection. The procedures in this paragraph are applicable to gradual transitions where flow remains tran- quil. In areas where flow changes from tranquil to rapid and then back to tranquil. riprap sizing methods applicable to hydraulic structures (HDC 712-1) should be used. In converging transitions, the procedures based on Equa- tion 3-3 can be used unaltered. In expanding transitions, flow can concentrate on one side of the expansion and design velocities should be increased. For installations immediately downstream of concrete channels, a vertical velocity distribution coefficient of 1.25 should be used due to the difference in velocity profile over the two surfaces. 3-8 8 e. Steep slope riprap design. In cases where unit discharge is low, riprap can be used on steep slopes ranging from 2 to 20 percent. A typical application is a rock -lined chute. The stone size equation is D3° 1.95 S°5" q 21 g �3 where S = slope of bed q = unit discharge (3-5) Equation 3-5 is applicable to thickness = 1.5 D,00, angular rock, unit weight of 167 pcf. D8.5/D,; from 1.7 to 2.7, slopes from 2 to 20 percent, and uniform flow on a down - slope with no tailwater. The following steps should be used in application of Equation 3-5: (1) Estimate q = Q/b where b = bottom width of chute. (2) Multiply q by flow concentration factor of 1.25. Use greater factor if approach flow is skewed. (3) Compute D30 using Equation 3-5. (4) Use uniform gradation having D8;/D,; ≤ 2 such as Table 3-1. (5) Restrict application to straight channels with side slope of I V:2.5I-1 or flatter. (6) Use filter fabric beneath rock. The guidance for steep slope riprap generally results in large riprap sizes. Grouted riprap is often used instead of loose riprap in steep slope applications. • 3-8. Revetment Top and End Protection Revetment top and end protection requirements, as with all channel protective measures, are to assure the project benefits, to perform satisfactorily throughout the project economic life, and not to exceed reasonable maintenance Open Channels Chapter 8 FLOW DESIGN WSE CHANNEL BED S MIN (5MIN FOR SOILS THAT ARE NOT COHESIVE) RIPRAP OR SOIL RIPRAP NOT STEEPER THAN 2.5H:1V GRANULAR BEDDING, REQUIRED FOR RIPRAP. ALSO REQUIRED FOR SOIL RIPRAP WHEN SPECIFIC IED RIPRAP DESIGNATION % SMALLER THAN GIVEN SIZE BY WEIGHT Dsa* (INCHES) INTERMEDIATE ROCK DIMENSION (INCHES) 70 - 100 12 TYPE VL 35 - 50 6 6 2 - 10 2 70 - 100 15 TYPE L 50 - 70 35 - 50 12 9 9 2 - 10 3 70 - 100 21 TYPE M 50 - 70 35 - 50 18 12 12 2 - 10 4 70 - 100 30 TYPE H 50 - 70 35 - 50 24 18 18 2 - 10 6 *D5,3 = MEAN ROCK SIZE Figure 8-34. Riprap and soil riprap placement and gradation (part 1 of 3) 8-76 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 1 January 2016 Chapter 8 Open Channels SOIL RIPRAP NOTES: 1. ELEVATION TOLERANCES FOR THE SOIL RIPRAP SHALL BE 0.10 FEET. THICKNESS OF SOIL RIPRAP SHALL BE NO LESS THAN THICKNESS SHOWN AND NO MORE THAN 2 -INCHES GREATER THAN THE THICKNESS SHOWN. 2. WHERE "SOIL RIPRAP" IS DESIGNATED ON THE CONTRACT DRAWINGS, RIPRAP VOIDS ARE TO BE FILLED WITH NATIVE SOIL. THE RIPRAP SHALL BE PRE -MIXED WITH THE NATIVE SOIL AT THE FOLLOWING PROPORTIONS BY VOLUME: 65PERCENT RIPRAP AND 35 PERCENT SOIL. THE SOIL USED FOR MIXING SHALL BE NATIVE TOPSOIL AND SHALL HAVE A MINIMUM FINES CONTENT OF 15 PERCENT. THE SOIL RIPRAP SHALL BE INSTALLED IN A MANNER THAT RESULTS IN A DENSE, INTERLOCKED LAYER OF RIPRAP WITH RIPRAP VOIDS FILLED COMPLETELY WITH SOIL. SEGREGATION OF MATERIALS SHALL BE AVOIDED AND IN NO CASE SHALL THE COMBINED MATERIAL CONSIST PRIMARILY OF SOIL; THE DENSITY AND INTERLOCKING NATURE OF RIPRAP IN THE MIXED MATERIAL SHALL ESSENTIALLY BE THE SAME AS IF THE RIPRAP WAS PLACED WITHOUT SOIL. 3. WHERE SPECIFIED (TYPICALLY AS "BURIED SOIL RIPRAP"), A SURFACE LAYER OF TOPSOIL SHALL BE PLACED OVER THE SOIL RIPRAP ACCORDING TO THE THICKNESS SPECIFIED ON THE CONTRACT DRAWINGS. THE TOPSOIL SURFACE LAYER SHALL BE COMPACTED TO APPROXIMATELY 85% OF MAXIMUM DENSITY AND WITHIN TWO PERCENTAGE POINTS OF OPTIMUM MOISTURE IN ACCORDANCE WITH ASTM D698. TOPSOIL SHALL BE ADDED TO ANY AREAS THAT SETTLE. 4. ALL SOIL RIPRAP THAT IS BURIED WITH TOPSOIL SHALL BE REVIEWED AND APPROVED BY THE ENGINEER PRIOR TO ANY TOPSOIL PLACEMENT. GRADATION FOR GRANULAR BEDDING PERCENT PASSING BY WEIGHT U.S. STANDARD SIEVE SIZE TYPE I CDOT SECT. 703.01 TYPE II CDOT SECT. 703.09 CLASS A 3 INCHES - 90 - 100 1h INCHES - - 34 INCHES - 20 - 90 % INCHES 100 - #4 95 - 100 0 - 20 #16 45 - 80 - #50 10 - 30 - #100 2 - 10 - #200 0 — 2 0 — 3 R PRAP BEDDING Figure 8-34. Riprap and soil riprap placement and gradation (part 2 of 3) January 2016 Urban Drainage and Flood Control District 8-77 Urban Storm Drainage Criteria Manual Volume I Open Channels Chapter 8 THICKNESS REQUIREMENTS FOR GRANULAR BEDDING RIPRAP DESIGNATION MINIMUM BEDDING THICKNESS (INCHES) FINE-GRAINED SOILS 1 COARSE -GRAINED SOILS 2 TYPE I (LOWER LAYER) TYPE II (UPPER LAYER) TYPE II VL (D50 = 6 IN) 4 4 6 L (D50 = 9 IN) 4 4 6 M (D50 = 12 IN) 4 4 6 H (D50 = 18 IN) 4 6 8 VH (D50 = 24 IN) 4 6 8 NOTES: 1. MAY SUBSTITUTE ONE 12 -INCH LAYER OF TYPE II BEDDING. THE SUBSTITUTION OF ONE LAYER OF TYPE II BEDDING SHALL NOT BE PERMITTED AT DROP STRUCTURES. THE USE OF A COMBINATION OF FILTER FABRIC AND TYPE II BEDDING AT DROP STRUCTURES IS ACCEPTABLE. 2. FIFTY PERCENT OR MORE BY WEIGHT RETAINED ON THE #40 SIEVE. Figure 8-34. Riprap and soil riprap placement and gradation (part 3 of 3) 8-78 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 1 January 2016 (WQCV) Chapter 3 Calculating the WQCV and Volume Reduction 3.0 Calculation of the WQCV The first step in estimating the magnitude of runoff from a site is to estimate the site's total imperviousness. The total imperviousness of a site is the weighted average of individual areas of like imperviousness. For instance, according to Table RO-3 in the Runoff chapter of Volume 1 of this manual, paved streets (and parking lots) have an imperviousness of 100%; drives, walks and roofs have an imperviousness of 90%; and lawn areas have an imperviousness of 0%. The total imperviousness of a site can be determined taking an area -weighted average of all of the impervious and pervious areas. When measures are implemented minimize directly connected impervious area (MDCIA), the imperviousness used to calculate the WQCV is the "effective imperviousness." Sections 4 and 5 of this chapter provide guidance and examples for calculating effective imperviousness and adjusting the WQCV to reflect decreases in effective imperviousness. The WQCV is calculated as a function of imperviousness and BMP drain time using Equation 3-1, and as shown in Figure 3-2: WQCV = a(0.91/3 - 1.19/2 + 0.781) Where: WQCV = Water Quality Capture Volume (watershed inches) a = Coefficient corresponding to WQCV drain time (Table 3-2) Equation 3-1 1 = Imperviousness (%/100) (see Figures 3-3 through 3-5 [single family land use] and /or the Runoff chapter of Volume l [other typical land uses]) Table 3-2. Drain Time Coefficients for WQCV Calculations Drain Time (hrs) Coefficient, a 12 hours 0.8 24 hours 0.9 40 hours 1.0 Figure 3-2, which illustrates the relationship between imperviousness and WQCV for various drain times, is appropriate for use in Colorado's high plains near the foothills. For other portions of Colorado or United States, the WQCV obtained from this figure can be adjusted using the following relationships: WQCVother = d6 0.43 Equation 3-2 Where: WQCV = WQCV calculated using Equation 3-1 or Figure 3-2 (watershed inches) WQCV0U,« = WQCV outside of Denver region (watershed inches) do = depth of average runoff producing storm from Figure 3-1 (watershed inches) August 2011 Urban Drainage and Flood Control District 3-5 Urban Storm Drainage Criteria Manual Volume 3 Calculating the WQCV and Volume Reduction Chapter 3 Once the WQCV in watershed inches is found from Figure 3-2 or using Equation 3-1 and/or 3-2, the required BMP storage volume in acre-feet can be calculated as follows: v _ WQCV) A 12 Where: V = required storage volume (acre -ft) A = tributary catchment area upstream (acres) WQCV = Water Quality Capture Volume (watershed inches) 0.500 a) r c ac Co U (1 0.450 0.400 0.350 0.300 0.250 0.200 0.150 0.100 0.050 0.000 Equation 3-3 I I 40 hour drain time Ill I I / 24 hour drain time WQCV=a(0.91 I P-1.1912+0.780 I I •o 12 -hr 24 -hr drain drain time a = 0.8 time a = 0.9 o0 40 -hr drain time a = 1.0 ••#. •� •- I. Oa l. OW a •� 12 hour drain time I . 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Total Imperviousness Ratio (i = la/100) Figure 3-2. Water Quality Capture Volume (WQCV) Based on BMP Drain Time 3-6 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 August 2011 APPENDIX D Maps — Historic Drainage Exhibit Developed Drainage Exhibit Drainage Details e MATCHLINE: SEE OFT -SITE BASIN OELNEAnON MM' INSERT (THIS SHEET FOR COMPUTE BASIN MAPPING NORTH OF SECTION 10 (I 4 N.YAK( weal) ('M! \ / \ ra 1 \ r 1 \ ti 1 i REFERENCED DRAWINGS DRAWING. REVISIONS AI, SABNS MI 051-053 ARE SISIUTART 19 GENY GREG. St0RNNATER IS °IN ITED OVERLAND SCUM It S0UTH.Ea caY 10 GLARY NRIIK YAW N( Y9t ►ARm 1 1 ,I( C A rt. 1 it) Q4W..IU+P ( FIPI N I.' • 81 LEGEND BASIN DESIGNATION AREA (ACRES) • 7L IMPERVIOUS 5 YR RUNOFF COEF. (BASINS HI. OSI t 0S2) NEC -22 SCS (NRCS) CURVE NUMBER (BASIN 053) BASIN BOUNDARY DESIGN PONT HYDROLOGC SOIL GROUP BOUNDARY (PER NRCS) HYDROLOGIC SOIL GROUP DESIGNATION (PER NRCS) EXISTING GROUND INT. CONTOUR (2' INTERVAL) EXISTING GROUND INDEX CONTOUR (10' INTERVAL) — TIME OF CONCENTRAnaN TRAVEL PATH A OFF —SITE BASIN DELINEATION MAP BACKGROUND IMAGE COURTESY Of USGS SCALE: I' - 1.500' KEY MAP HISTORIC BASIN FLOW SUMMARY BASIN AREA (Ae) OS (CFS) QIO (CFS) Qt00 (CFS) HI 0.96 1.0 2.9 11.4 OS1 22.46 2.1 4.7 10.9 052 9.19 1.2 27 9.5 '053 250.51 13.5 25.3 100.0 'BASIN 0S3 FLOIIRATES CALCULATED VIA HEC-22 SCSI (NRCS) MEM00 (HYDRAFLOw) SINCE THE BASIN AREA EXCEEDS 160 ACRES. ALL OTHER BASIN FLOMRATES CALCULATED VIA THE RATIONAL METH r R AND ON Slow.. O ...E DtSO. Gll P Etc DSA •STDNI CORSIATANTS LLC Ir regrow. -wwN. ✓t h YDNEANN ChM 01 m on% r.h.lw ) A: (1 Ail TOD (71 UW S% DH^ «I.DC HAS' .A5 t40: HUN PUdUSPIU HUI RAIr.� 'i_. r. r� •<EPAREO BY LAP ENGINEERING t CONS'. ! )N SERVICES. NC FOR USE BY THE Co• • NAMED N THE TITLE BLOCK SOLELY IN RESPECT 01 THE CONSTRUCTION, OPERATION ANO MAINTENANCE o' IHE FACILITY NAMED IN 1HE TITLE BLOCK AND SHAH NOT BE USED FOR ANY OTHER PURPOSE OR FURNISHED TO ANY OTHER PARTY WITHOUT THE EXPRESS CONSENT OF ZAP ENGINEERING R CONSTRUCTION SERVICES. INC DRAWING NUMBER TITLE REV DESCRIPTION ISSUED FOR CONSTRUCTION BY LJM CHK JME APVD KWF DATE 0 09/30/19 1€14:13=11, .10.I 997610 r- 1. N(.1N11taaO A CONSTRUCTION SINVtCtS. K UTRIGGER ENERGY BAYOU COMPRESSOR STATION HISTORIC DRAINAGE EXHIBIT JOB NO 19128 DRAWING NO 19128-0O3-2001 PLOT SIZE. ANSI D ISCALE: AS SHOWN REV 0 MATCHUNE: SEE OFT -SHE BASIN DELINEATION MAP INSERT (MIS SHEET) FOR COMPLETE BASH MAPPING NORTH NY SECTION 10 I I ..,/ / L I / 444.44 11 POtp W Oar* - a FT PEST LI NDH 11 (_A ►OND 7NASE C17MO= WI 0 -STARE OUI1OLt simian POND 6YWMML - AI I ai IwTrDERI RPROVO wows=1) +/ w amtL/01WV RALE 1\\ LAN Trm= 444141 9�Y16.44` 1 U t�S1\\ LYA 1 KIIMDOILIENLEI6SELC!) 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CONTOUR (2' INTERVAL] EXIS1NG GROUND INDEX CONTOUR (10' INTERVAL) TIME O CONCENTRATION TRAVEL PATH FINISH GROUND NT CONTOUR (I' INTERVAL) FNISM GROUND INDEX CONTOUR [5' INTERVAL) PROP STORY SEVIER/OULIERT, OUTLET STRUCTURE Et FLARED END SECTION CHANNEL SECTION CALLOW' RPRAP EROSION PROTECTION [TINE L r54 It IS 00 I l/101o1 OVERLAID FLOW ORRECTION OVERFLOW DIRECTION/PATH MAIN TENANCE ACCESS SIZE OUT! ALL N 4 OFF —SITE BASIN DELINEATION MAP BACKGROUND IMAGE COURTESY OF USES SCALE- 1' - 1,500' 0a KEY MAP ..SR BQjCA4- '\GE 114 L t10 YITNIWOW NY'M A,:k. USR BOUNDARY (Tyr') DEVELOPED BASIN FLOW SUMMARY BASIN AREA (AC) Oe (CFS) 010 (CPS) OIoo (cis) ' 01 age 7.e 10e 24.4 OS/ 22440 2.1 4.7 tae 002 tie 1.2 2.7 e.5 CM 280.51 13.5 20.3 100.0 A9ASN OS) rLOYRtATES CALCULATED MA HEC-22 SCS (MRCS) YETH00 (ElYDRAFLOR) SINCE 111E BASIN AREA EXCEEDS ISO ACRES AU. OTHER BASIN FLOIRA TES CALCULATED MA THE RATIONAL ME7HO0 rdA MS GM ecIMat Of JAR OIS4D. GIMP. LIZ IM C441lIO a COYSJLTANT6 TLC in rr--S OUT. *MITA° CMS 0101100 GA___ .y 1 166484P -Mill T t4µ1 N ER SSW UN WPM Dr OC THIS DNAW,tN Ia. NOT BEEN PUBLSHLO BUT IRONER Si BEEN PREPARED BY TAP ENGINEERING & CONSTRUCTION SERVICES, PC FOR USE BY THE CLIENT NAMED N THE TILL[ BLOCK SOLELY IN RESPECT 01 Ittt CONSTRUCTION, OPERATION ANO V INTENANCE or bit FACILITY NAMCO IN lit TIttE BLOCK AND SHALL NOT BE USED TOR ANY OTHER PURPOSE OR rURNISHEo to ANY OTHER PARTY WITHOUT THE EXPRESS CONSENT OF TAP (PIONEERING It CONSTRUCTION SERV CES. NC REFERENCED DRAWINGS DRAWING NUMBER TITLE REV DESCRIPTION BY Cols AND DATE lJM 0 ISSUED FOR CONSTRUCTION JME KWF 09/30/19 I ZAR wt.n. rMSG 4 CON4tNUC11OM SINVCIS. I.c OUTRIGGER r) ENERGY BAYOU COMPRESSOR STATION DEVELOPED DRAINAGE EXHIBIT JOB NO 19128 DRAWING NO. 19128-0O3-2002 PLOT SIZE; ANSI 0 I SCALE: AS SHOWN REV•. O PROPOSED CULVERT F C.S. HEADWALL/aNGwALL OR CHANNEL W/ CUTOFF WALL : PROPOSED CULVERT & FFE.S. PLANS FOR 1 L (SEE PLAN) _ /vw� E 0 �VMENI - (SEE ENO w x T DETAIL TREAT1AENT TYPE a SOLE)(THTS SHEET) 71 -19, t .. ENDSEiREA YENWrOENtAK •' '-1-i • __ '` I SU EDC - (17.4 SHEET) R-•� THICKNESS SEWS (MS TYPE I. WRAP 2.0 . w-) +i NH nuCNN[SS 2.0 TOMS DSO �1 .1 Mt AIYEMT D(TALS (THIS SN[[T) Ij 44* MGM 1 •• GEORXIR.C rAE1pC PROF>Lr XL Elms RIPRAP CROWN PROTECTION RAM VICw •PRAP KSId•Ps, R u•I.:P T.r. RAIN f7I RT N1N "Pill" inn IMP (HOVE (OR APP'S EQUAL) • (011 APPROvEO LOUVALENt) OIItNLOw IA1FrA1 LOW TAILWATER BASIN RIPRAP AT CULVERT END N' - •W 17 (ONO) 'Wr A SD - 70 M - 50 • • e 144104404 R/DYA/KN'L /OR OYMAY avow -. Scat. NW 0RR•AAR •IDOWw • - 'O E sea •COMAE IHttWV4 iM:H[11 rEROR MOWIG IP IDLWT A - TOO Te (0100) •IeP aENUYmA nw-o•Mlm 70e.1 ' C0M]t-plAwC7 701.6 r us 011000 Mt MI. Tn(I za21 tt Hug' NNW IT sal ILO MIN Op• • WRM t•ON TIDE ' 70 - TO 7• - So 1, I ° 161I1 (LL>•M LAYER) Mil a 1'ORIR tAnwn ML • T was - y[ - ,•p 1 '0 S ,• r•Dcs ' - OEOTEXTI E FABRIC RIPRAP EROSION PROTECTION: (OR APP' $ EQUAL) Rf SEE PLAN FOR SIZE DESIGNATION • -„,r SO - t0 ]T (0100) • L (OH • • •O • • • • w) • • • * �� - >m - b f A main'OC - u WRAP GRADATION TABLE THIS SHEETD MIN. THICKNESS • 1.5 TIMES (0.00) SO 1 - '0 el 4 '7 Y (0M . t7 •) -- - - - • - • • It e • KC t - wt L H TON a 10 IN) • • — -- R I1• y - t • - TO - SOD SO (0•60) M Ow a 1• W) NO '0 - 1r. GRANULAR BELONG SEE '. GRNNE55 IN 10 IC 14 • • • i RBELONGEN IS "'APL - 60 lit `• OHN I • 10 - (THIS SHEET) , • 'P • NOIU pm r I I •Ow- WNw Ii6/i YIP • • WT TYPE I SttOONO I 'la.. I HI :IF Tn x R19(NK. MIT YAbc 41111 Cr OM (AWN - ___ - c0Y1lIIA1x* at rraft aar AND ROT IPE NA A et•a AT 0401FIPRAP )1L'nrMN(: Mt.Ttfl A AIIN • ct'IAML / cOYPACTEO %Hwa g g[ PLANS raft LDCAnoto • SUES Or (PREPARE PER PROJECT RIPRAP EROSION PROTECTION Flan •.N. GEOTE CHN•CAL REPORT) RIPRAP SECTION RIPRAP GRADATION : Fr AMPLY 0• Law e• wtEnt 41710412) d NW I.0 9RLE Rlwrrw sad wad drop PI•nwS•r •e/ frelYlw Howl I 1 J1 flame 144. WlwrySpew !atoll SpMeennew•e• pdr4ISMIMY+Aipimentoe • 1 MEI tine•J•. R•.pimento w traNIAe Ian I a I, TABLE GRANULAR BEDDING GRADATION TABLE & THICKNESS REQUIREMENTS URBAN DRAINAGE • FLOOD ®RIPRAP EROSION PROTECTION DETAIL cONTRa DISTRICT URBAN DRAINAGE & ROOD CONTROL DISTRICT • IE 1W/GY/Al1REINFORCED JO' (1W) OUTLET PIPE I POURED IN -PLACE CONCRETE HFADWALL/MNGWALL & fVWylEC 7 IAN1.7•}N }LS' WTOfF WALL REINFORCING: I /5 AT IY O.C. EACH WAY B -_t (T'TP) N T.S GROUND r 111RSKD T fl,, I.67' OUTLET PIPE OUTLET Tr GROUND 1.67 •. 17 ,L` �•RERfORao COOT PIPE CONTROL I 'CONTROL CONCH!It WALL I REINFIRCE01--1 PIPE PONT I J' led ig 0 1' IN PREPARED SU AIWA PIPE NOOK YUGHT PIPE cDNTROL POW1 101 POST CONCRETE ISOMETRIC VIEW cv T(xr WALL SECTION A -A IIAtr REINFORCED CONCIKTE CUfOrr WALL ()MlpRiN° IN 4.IN \\V/ AT SECTION B -B .1 u' YIN ) SITUATION 'CUT SITUATION ($[[ FLAN) /!- G HEADWALL/WINGWALL END TREATMENT (DOWNSTREAM END OF POND OUTFALL PIPE) ,pp, • S. A SMALLER PLACED AND DAYLIGHT ` /4:1 • „t ROCKS TO BE HAND FINISHED ''T•e Cl GROUTED IN PLACE GROUND / J 4d j1 , g� 4• f , I'° * 0 • 4, .4 `b SMALLER ROCKS 10 HAND PLACED SMALLER TO HAND PLACED BE HAND PLACED AND SEE TABU RIPRAP. / FOR SUING. W/i W/2 _ -' • '�,4' • 0 :C 4:v BE HAND PUCEDSANO RIPRAP. WIN 0 WIDE GROUTED w PLACE. •�/ • MW 1 1.014 GROUTED 04 PLACE Lr� SEE ABLE NANO ED RAP.SECTIONNAG AT SIDES OF TES. • • FLARED ENO • • • I�,/�D \�,� S, j �l- ,�J.�� 12- --��{{a' I, I , 'I TRANS TICS 1 SLOPE COMPACTED SUBGIAOE ,\ (PREPARE PER THE PROJECT I FLARED ENO GEO'FORMAL REPWT) ACTION PREPARED SEE PLANS FOR CHANNEL LOCATIONS • L.�� GEDTEXDLE FABRIC (OR APP'Vp EQUAL) OU PRE SLOPECTION RA G•I0- SEE PLN1 FOR Sit DEMNATION • •� IN -PLACE J Mw CHANNEL ; U nut•. SUOGRPIPE Aa SURFAGNO/SIABIL17A1X)N REQUWEYENiS CON�aT - FABLE THIS SHEET CHOOING ��POWItO ��a CONCRETE CUTOFF WALL J' wN�� BEDDING I K`+ [•, •, TES GRANULAR BEWRAP gEEADATION E TOE PLATE EXTENS1014 (w cONC OJT0FT WALL) w/ p S It D.C REINFORCING OUTLET PV[ POURED IN -PLACE FES BMS Ai tY O.C EACH FLA 70i CONCRETE CUTOFF WALL ICS CONTROLW(TIN) PONT W/ /5 REwtORONG BARS PONTAT it at. (ACH WAY TYP TOE PLATE EXTENSION ( ) CONTROL PONT TOE PLATE EXTENSION (IN CONC. CUTOFF WALL) POURED IN -PLACE CONCRETE once' WALL CHANNEL DESIGN TABLE THINNESS RCOOG4G TS (THIS SHEET) ' Lintz 1 ON CONC. CUTOFF WALL) WI /S 5 REINFORCING BARS AT 1Y at. EACH WAY (TYP) CHANNEL / ERN. W (It) YIN. 0 (It) SIDE SLOPE A (H: V) SIDE SLOPE B (H: V) it ]v r ISOMETRIC VIEW SECTION A -A SECTION B —B on 5.0 1.0 4:1 .:1 s$ COMI/11 j7? NOTES u ` t CORRUGATED METAL PIPE SHALL MEET 0007 STANDARDS (RE COOT STANDARD PLAN NO. Y -00.7-t, METAL PPE. • SHEETS) 2 CORRUGATED METAL PIPE FLARED ENO SECTIONS (F.ES.) SHALL MEET COOT STANDARDS (RE: COOT STANDARD PLAN NO M-601-10. CONCRETE ANO METAL END Pm AND w It KW CO SECTION. SHEET 1 OF 1, 0001 STANDARD Y PLAN NO. IA -603-12. TRAVERSABLE END SECTIONS AND SAFETY GRATES) FLARED END SECTION END TREATMENT at ore` &sod MP 1tC WA Owe CasA'Arts 1LC '...•w.•.e•.•. 0W:T • Irks OWNS ®END TREATMENT DETAIL 3 DRAINAGE CHANNEL DETAIL 8�' Am ' N.T.S. 2010 N.Y S is II)•Hosol AI 'ILO IL I) WHIN U OAK -- -OC •H4 DRAWING HAS NOT REIN PUBLISHED BUT RATHER REFERENCED DRAWINGS ()RAPING REVISIONS St; RN 991611) - -••'••"e •- ZAR rNawR•Ie o•eaNRTwlltr•aM NNYICI% -c f� o L I T R I G G E R ENERGY BAYOU COMPRESSOR STATION DRAINAGE DETAILS 1144 BEEN PREPARED $T ZAP ENGnKERWG a DRAWING NUMBER TITLE REV DESCRIPTION BY CHIC APVO DATE CONSTRUCTION SERVICES, INC TOR USE BY THE CLIENT 0 _ ISSUED FOR CONSTRUCTION LJM JME KWF 09/30/19 NAMED IN THE TIM (KOCK SOLELY IN RESPECT or THE FONSiY1 ON AND LC NT CNor - NAMED IN THE THE FACILITY NAMED IN THE llrlC BLOCK AND SNMLL TOLE SHrCEALL JOB NO: 19128 NOT BE USED FOR ANT OTHER PURPOSE OR FURNISHED DRAWING NO: 19128-CO3-2010 REV TO ANY OTHER PARTY WITHOUT THE EXPRESS CONSENT of ZAP ENGINEERING ! C[N4STRUCION SERvCE5. INC - ------ - PLOT SIZE: ANSI D SCALE: AS SHOWN 0 COOT TYPE C INLET BOX 55 PA B (SEE COOT STANDARD PLAN M-604-10)1 11\ i 0.I" 3/e" GALVANIZED I COLUMN, 3 ROWS, PLATE TALL X 2-5/18" WIDE HOLES SPACED AT 4" O.C. TOP OF WO PLATE/ (re) BSIGY_W S. 1. EL -5413.11 1-- 15" (TIP) b45412.77 • 1 NOTE CONTRACTOR TO FIELD VERIFY REMOVABLE ' W 5412.44 4 Cl-} 1.19 TRASH RACK DIMENSIONS I PRIOR TO FABRICATION 1.1::____ / 5412.11. _ _ 1;stt a _ RESTRICTOR PLATE DTI • (MI5 SHEET) 3.00 4 00' 9 j7�Cil ELL -541T a _ITILFIAIE_/ L-175•-.� s/e` STAINLESS TOP VIEW SEE WO PLATE DTL THIS SHEET) (JC BOLTS (TYP) 2))K2)j0Y4 STEEL SQUARE REMOVABLE TRASH RSTAINLESS AOEL VN. TUBE MELDED CUT TO ANGLE. K WATER QUALITY WQ PLATE DTL WITO ALLOWTRASHRACK (JOHNSON WE ORE OA TRASH •" 0.85 N.T.S. STAINLESS STEEL SCREENS), TO SLIDE THRQUGH (TIN) OR APP•D EQUAL SEE RACK DTL (THIS SHEET) UPE MG 1 2 r 2 0' 2' 3/8" PLATE SUPPORTROO : I I 5/B` STUNLES5 BOLTS(TvPl 5" (TYP) 1E 0.074'103W A • • I FRIWE !/8" X 2" NOUN.) PLATE I A A it • 3/e GALVANIZEDi� I ?Y 5/8" STAINLESS BOLTS (TYP) 2TO 1 L3X6X1 • - 400 �.1 5' (IYP PLATE10 THE SIDE Of THE I ` p3 VEE (T`/P) • TRASH RACK (TIP) 111 FRONT NEW (TRASH RACK FRONT NEW (REMOVABLE TRASH vnl.• HORIZONTAL t VERTICAL 1.�1-0 _1 y0! jrL FA TER SCREEN ASSEUSLYL FFMNNFrDOE In OUTIFT STRUrI.. ,.. OUTLET BOX PLAN VIEW CONTROL PANT (SEE PLANS) B v RESTRICTOR PLATE DTL REMOVABLE TRASH RACK DTL 4 O0• N T.S N.T.S. N. TS 100-YR MS 6- 3.00' 6" EL -54T4,13 NOTEG- TOP OF BOX/GRATE - 100 WEIR1. CONTRACTOR TO SOBMIT OPENING IN CONC. ABOVE WO PLATE 2. CONTRACTOR TO FIELD TO TOP OF BOX DIMENSIONED & SCALED SHOP DRAWINGS OF OUTLET STRUCTURE, ASSOCIATED WO PLATE, REMOVABLE TRASH RACK, ETC. TO OWNER/ENOFEER FOR REVIEW & APPROVAL PRIOR TO FABRICATION. VERIFY REMOVABLE TRASH RACK DIMENSIONS PRIOR TO FABRICATION - EL -5413.90 I V 3 FOR TYPE C INLET BOX COOT TYPE C STANDARD INLET GRATE SPECFICATIONS it DIMENSIONS. REFER TO COOT STANDARD PLAN NO. M-604-10, INLET, TYPE C, I SHEET (SEE SHEET 2012). 191�25''V CONCRETE OPENING Y ♦— (SEE COOT STANDARD PLAN Y-804-10) EL -5413.11 SEE WO PLATE DTI ♦ --- .'- '� t SEE TRASH RACK OIL (RRs SHEET) @ �Fpp ��THIS SHEET I I ' %" -, ' IL 4,t��i -. _. ELF -00 \ J BOX INVERT/ \ _+�_{_ � y. •i-- _ I ) ,/ de _iD ROME TRASH RAW L- -OF BOTTOM OF WO PLATE EL -5411,62 ... - -4 12' PE4710 SDP Ti' SEE RESTRICTOR PLATE DTL !" DEEP QUITALL PIPE (THIS SHEET) 3" PROCESS WV 0111-5411.02 SECTION A -A MIRAFT SOIL OVERRUN BY AREA GRAYER (1.Y MINUS GRAVLL) 140N TYPE 1 BURIED WRAP3" DEEP SOIL OVERLAIN BY Dm - 9" S" PROCESS AREA CRAWL N.T.S. FILTER FABRIC 5' MIN THICKNESS(1S 2 TIMES Dso 5, MINUS GRAVEL) 100—YR WS 1� e 18 EL -5414.13 \ 4 00 _ �� _r_ TITS L BURIED WRAP THE OUTLET PIPE IS TO BE ---_---- `� LD• TOP OF POND Dm IY. I - _• mu/GRATE 3 09 BACKFILLED WITH NATIVE EARTH �, .-�� _71' EL -5418.0 I SOIL. NO REDOING MATERIAL: .. _y - •.-: 4, MIN. THICKNESS l ' cl SPILLWAY CREST EL -5413.90 I II , �--- 2 11LE5 DSn SEE TRASH RAG( Dn ). JI + �" I K .. - EL -5415.0 - -_- (THIS SHEET)\ I SEE RESTR1CT0t PLATE I ` B' WIDE a 3• DEEP . 44.0' LONG ''- 11.0' 0" REDOING4:I.•I++r...r.w .�'•_, •. „`.:.;..,.� DETENTION POND TRQCy R•g _ \ Y Oil SHEET) POURED IN -PLACE CONC. EL 1 j* (1 (1TOS \ e" MN 4.0' 26.0' -54 r SEE WO RATE On ` CUT-OFF REINFORCE WALL COMPACTED SUBGRALE (PREPARE PER PROJECT ' • OWIDE 80. 9M 4F_CQ21O_ E1-5412.00 IF 1 7B �' f (1HI5 SHEET) A BOTTOM OF ELS?i/�Ti - LT 49' 12" iTrAu, soRIK 11 OUTFALL PIPE (QLTRIGCER PROVO PIPE) - I I w/ 12" O.C. EACH WAY 0 AT TIP !d5 •6'' . �1 i MOTECHNKAL REPORT) e' - MNRAFT 1401 REINFORCED . 3' ca://0 FILTER FABRIC CUT-OFF WALL COMPACTED SUBGNAOE •• I . BOX INVERT/ ` LIG C~ -=•4 1° - 6" GRANULAR BEOQNG [•A•I'•' BDIIdl.SL7RASM_BACKI L 4- I I (PREPARE PER PROJECT S BOTTOM OF WO PLATE NV OUT EL-s41Lu � ----------- -- ' 3• 3• $,- � CHHICAL REPORT) ` • ': EL =5411.82 CONCRETE CUTOFF WALLS (e" 1HIGL)— I SECTION A —A SECTION B -B +y��a�po4.1 ,'1•c•'•A PLACED AT 1/3 AND 2/3 OF THE PIPE LENGTH - EMBED ir (MIN) INTO UNDISTURBED EARTHEN SOIL (TYP) I NO. 5 BAR.Ls 3- aR EMERGENCY OVERFLOW FOR AND ON At SAO CO SECTION B -B MICAMAO N.T.S. 1 DETENTION POND D1 OUTLET STRUCTURE & POND EMERGENCY OVERFLOW DETAIL C HS1C1 9AIat6�i r. & masLN Cf4R1 .:T•Nta. aCL:1• F DXIIACO ^q g 2011 N.T.S. -\.% I- r- m -•Nn •' tIMt NO OT RANKS an WW IOC OL I I.6 DRAWING HAS NOT BEEN PUBLISHED BUT RATHER HAS BEEN PREPARED BY ZAP ENGINEERING t CONSIRUCIION SERVICES, INC FOR USE BY INE CLIENT NAMED IN THE TILE BLOCK SOLELY IN RESPECT OF THE CONSTRUCTION, OPERATION ANO MAINTENANCE OF THE FACILITY NAMED IN THE TITLE BLOCK AND SHALL NOT BE USED TOR ANY OTHER PURPOSE OR FURNISHED TO ANY OTHER PARTY WITHOUT THE EXPRESS CONSENT OF ZAP ENGINEERING it CONSTRUCTION SERVICES INC REFERENCED DRAWINGS DRAWING REVISIONS ZA%lp SNowlllWG A CONSTRUCTION StWittS ' ' OUTRIGGER ENERGY BAYOU COMPRESSOR STATION DRAINAGE DETAILS DRAWING NUMBER TOLE REV DESCRIPTION BY CHIC APVD DATE 0 ISSUED FOR CONSTRUCTION UM JME KWF 09/30/19 ''`� JOY 991.4113 ^""•'-r°•'� JOB NO. 19128 DRAWING NO. 19128-0O3-2011 !REV' PLOT WEANS, D ISCALE; AS SHOWN 0 - OW Sr MI `■`• ♦ lw,rua Ma �t� VO W< E .T] 11,.D IokA L ll��mIr(n'6"" -r as A I N l W T Pa•' __� �� •`'`r"1�>Ir rrrrnw.r. .u'. 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JrPIGK CONNECTIONS "HP sum afnlrtrwcrw,a �! • RWIF1'TOt IWTAat 'a KI. alx,a tx•n law u • ., '• . .■ w er Yi(1Y Ira TIIl1 F C� YI 1•g QC VIEW XX LIM PI,. :a .MINI In OWE lath IUt -44 I>•4M2 } AIM Lama S ` A U :' a at n• Fie CFCTION £ NC CONNECTION DF TAB C FOR IMRE) NQ ARCH METAL PIPES L.- 0 la RI Ono Mon AT 7C., •I•n I ICS •I• ILSI 4444 View-am.rratr 64 • a Y Ti t 1 W _tI C•"• a r r1.lt• IS lR W:C ww. • won_ fir 11.14 LA l C ( L l E A C L E .K. n>r¢• 0' A' •.. 1rw>t t littoo�11/, W S IixMi ttEt/L ,_ EKI SECTIii$ iDR PIF•E >RCl1 ;;LIVER• vow qy1 M T U t V Y M 5 4 4 ■ w. It 1. SI 4WIx:l.Y11RY •y-Ll Y N N T ■ O S Yfr-•YYP in T. / 111 1 l YII'1WIY W1 IR y>(ptr �� tomcat [ICR a E It 0 lr •• bUn 'Seb•6 -_.~••1 _ • Y a r 1. 2• Y y CAOMICII OAUV,t! OA nnl �� '`�� I.F` •WU lab XV caw w we two 1w • I • T — Y L 1 n ID .Yea Y la Si M u ■ r • • 1 X r Muse '1 M �.. R, T OfM� i �.. ri•_ m I_1\— LWOW II r Y •041/0 l tr a et t Y 36 a y a h 'CI n4µ I -_ Z • —•� qlr M S• a • • • -It 11 Y� Y E� N • M r 11 *MAr i : a Y a - /. ; ~ SW r•, • E _ -a---l4En n r r Y —n n DO SECTION FOR REtKORCEO IObtiO A•Aw r r.rlmr el•�E .�_�I_XL. / 11 / V 'm T II MIN'S P FOHCAF L F 1 TI M PIPE w• II Ile a I•• Santa a Y Y LS a a is Y • a eEDiaCEO i Cb1CJ1ETE CIRO_AW PWE W a I Ih l I•. • M PIw• W / •.x le a*With MP, W h \ ♦ N. S1• UCa N a Y >I • a a M FI w .•I nCIS1 n PIM / • R' =till'. * •n Y ••nt•a n.• aT1.-•I1. • 1t' -' .4411 Vf Illil.de M is �w a • ■ RI 1►R IYTii�4nl I 4AC M a • ti u • 4 v w •I N w anrlr 1141 sir'uMY 10* SX IM I1• I(IYWrViallLal:l \ N 00.40FYaf H q X 1Mpl!IR ■ a r, :N 11• IM1A [[11 •ICY_! maw.ilel» I: - M W T Ur Y•IT 440 4.44 I •• r -II y ri F ill : _ L4SR .t_ I.1. 4411 -1\42.014, �1rn �jj -r T sets T - - - -I aYl r I rf•,1 /� pMllu Pt MAtNACr END uf7tftd rs L u w oar, �p,�,y 1 FY �.-{ la PPS std ~ aim nit Dr •now . !' =ETON X-tIUSLYJIR f 4 •l. x STEEL £10 SECTION FOR ti u r • s 1Vela - +•I 111 t {. MCP a l_ E....� 1, JrI _L ]°411,['4 Crrlsai B -R .IEILIatilMatt• rtE•1..twa (�RCREIE CIRCULAR PIP( n • r • CAS END SECTION FOR lIEQEDRCED CONCRETE CIRCULAR P APE ulYSn• N POI If sent grjf WU TL LINT FASTT$ER (TWO PER LINT) Clint BAR 11FTAR t Computer Fie Infamadan )wl R•Ylrar• Colorado Department of Transportation STANDARD PLAN NO Computer rile Intarrtgtlon 6�'1.�.__ l r..>rpLlN. Colorado D•pallrlrlt of Trorrportobon STANDARD PLAN NO. g..... • .... mr• C"l:.r : n.. CONCRETE AND , .•:. .v. J l i• Cm. tmeat• TRAVERSABLE END SECTIONS (.1•q AY MD �...... • tr, •,•• „•>, I Re con OA x• •..• M•603 -ID 1"` " t:. • •, '° ° •r.•.: A•• `•' a Mfi°T"1 s tie larhr•r Oar C)Trm ® >x_." •t>a. METAL END SECTIONS '=�' 'Y `. :0=-:.t"t mr're AM) SAFETY GRATES Standard SlScct No. I 3 Os4 y1.11lc _:a (_>y •Xrw >)a-:vsaa r.l. w-nr-tYi Slazldurd $hLYA No. 1 of 1 1014." Ny •:, anti Xe ,,,'tth;a0 lw• 1114404 of CM r1• ' tans TI um r w 1.1. ,h I.fw YT). Project Da,SO lwll Branch a Nam. pp we w.(•rl c.•Mr. •N a„ 1»:JLt al 'met W.: c CY w: rLY+S..i 4s .r Y YY LYx !r¢• CM Project DWtI0PYr11E Branch AK 1••J •i !• h...a1 ',ear.. amt. oar U. ]» •r•.-. Ye ...mi. 3-g1— DEt■1•Y RnTre -- 1°"`L•• w Al Yln Y�• —.1 %INRTTIES KR ONE INLET S'TEEL - ATE OU/NTTTEES Tea /< y • �A • • I _. 'a@E (Wi e e Yy}Y 4 IYN '� E••'' - r fM y •Y! i•1• ' 41.461 Pal IfFat-ie- -1 •rra a •t■r H r .q: PIA OA. f.>I}Y K Y II 0000•141 IPSO •v AYwa Ma la. ( W tw I M 10054E r •ir•., Viii F >xkt •�� I awl /t II Iw -1•r M a.;L- • Y r liar lS it lE W .I' I . L. 1 I r• ;•r1•I E7 U I� Pea J all' S Y R SSW MI }U Cal>Y Y 14 6411911[444 • 1.Y'. •- ('ss • r l LA M N•� ■ 1 •44.4 •a • 4" K kmair r r • I! RN . nS�r(;pi • F 1• a :N 1 ' --..31..4.72':I� 11 I. •••Y I' 9.DT DETAIL -•M. it _I _ 0 11 014]4 1 sup. cam ,wl • 1414n w•M Is+4[Iw IY.w ,. M ., t. air weal 1 a (y CttK�,4��{1({1�trwN Ora 511,1 L. ('- at' �r r/ l•u 1•w 1 Ns Mi • 41XX Oa IJY4YW XIX Y M Was P J..:. -rte 1004]v,i mas N•WY.•wn + YW1 t ! -ear dt Y- I •�r �.>- f it. •YII •I', t'(:L 1 ;� -we row :uY4n • . " •16' GO bH`• 101401W - Il -I �". 1 Ina S. 6044 r r• ry lJd■uw\ �. • tIKWM K Yr AM r 40A alas MSS 1.m [spy \ \� H 0tta M I Vlnit*Y N w PY6 P• POI Wig �• eo'1- . . . . . 4• . n 7 _ „Q1•(,' Viii. a• 1e 04 salaam talus p1 yI r LI16t1 w♦ r/ J •'/ \ >iliw PTA1 • ■10 a w.. Tl s 11. • MPS. 44 1.a al WIRY OS Al 1 • I. tI 1w •• - I1._., r. r* .!. 1.1. (•. r I. • rrar�.•t rp•�,yy SiF 'Y �` $�fAtLAtIQ1 Lot lttclta K MULTIPLE MEIN- a r M 0144 w1N•ua wu • Ip 101000•Id r1. l4r 4R .Ilea -I. awa•rall• M•Y r• rf tYIOI a M n14•n Tea PIPES 1 1 I • x, • rte. r K• T Vim• 1• 1 IM• RILW ALTERNATE WIT 1 a EwA o -a Ir':I•:.• N 1•v 1 -E• Il ii i IDSTALLATION --- diem Pair DF METAL _ .j PIPE r >�wnµalCu +iYrwwr CAM. di Nw•Pal ewCn•«.•It- M r.r u Yt . •1 • ,La' rim « IK Ira PA M64i++Y1■rLa aX1Ma -r B ., lr•r . -. 0. ORATE O35TALLATION PLATED •r •I I OLtT Wliri D1iCri PAYDj(i SIC. !DIN �Q� a YRW , 1w a' It r•I ' a T w, n1• 1YI.t H■nrr w nu •M t •• tails SYYY9• t2Yl la raw( PISS a %a Roe viva 414414:• 4 IN *Ur It St' I W 8 Mt S41 WW. la r'I: • •. "r ii Kk' fib•` •1.q 141‘w Moir . Oar 'PT 1 4 t1 It S MO •• sal Cl r aCL w 4.16 if•tt IM Al I *Al A nIIo tar MOM YYIY CAN) AA O[SR Or al w4 la VIII Yrfllxl • * E T MC aille SNP MUM flan ago Oi Mr Caw II r 1 bt, 04 Pang SIT rN Ala III ••I0,4b•11.[041.1 Cr' INN iT rest �. f t.Rs • . •r•• p. M• • otl t WI is ■ (qIM. Q a wL-C' a all OW iD I RK UTXI NT Oar S MI HS 5) W • W W -l1. I1. • W SNP - W 0 111 644 SOD '* • .r M. Saar a 4rITGI.a a .4 IaroV • VTR! MIAMI w'4 (CP I M all j ]ran > I.1 _•,••a .c.1• I • ' Ian' t y i. �. -, (- ) ants 1.b Sal ! aim warn Wlli:,tt wows M •t' VIII Mat 'MY: eta • 1/t! W1 5• 3 fRi •>2 YMrt, • •1.G I1• M WW! L1 '.:: r C M • X Y 1 _� r ..„2Pl1404 •Y Imo_ a --1 • itRti EE: ION f 41.,1: oaf• F.•I! Win •••1! 4111a• ]:Par, WI. •I L T: ■ a M •e LEGEl� •w S. 4w• IIV. ama� , • 1 'I- SOW! 1 III n • Ora § t. l f - coon 1.91 •r1• •,.tl • UM DEMING DIAGRAM - L•J - n: >1( T l IMAMS PIM ON al•41 ea Ma sciaisala am as. H rrbl l(•b a I��-- Iasi •Ytt IW 4l•1tl5 IS (Y MI a Madame %M• a A Cady CU LEMMA TTI is . 4-wli WC. 4 a N y ISIS( tml sI IAYY1t 1•I f M lell a *C. T•f•n A� .• • - U • 11 Hr a A• IAN I .t Vii4te OW ■Utt ML a *a Y Y •1R C Valli talp 4W XX Stl '15111 •1>tau i V RR a r�JJKr11 !Y Keg }Y. • 4 SOS a MX Ian 1• //// CMOS't*Or 4440gavinall a naV4• LIINIYUM COVER FAIR CONSTRUCTION I QMS I�1{S t - ilai tr •WO el -'— a• 545 nal MOM a i K N • N :I•• sr Zan r} pa ■ a,R• M •r a KT W M afro T'4•4000.1.411 r qr NO oil .. • ASS - .'Ya:14m r1. SECTION P :.I Alai A- r! •M i>- arwt 10X1] In 'w IOW. k NIT Ma 1-t a lar/•9MWI a EMU ala a 0Mai y •µM • twa 1.4 E Mae ••• all MOM Na tat 40 .. . • _ TJ• V to aaa TM. PIPE WITH WITH END END SECTIONS nl 101.1w rr l ve, r4 I. e. a 4 al : M u.> M ti f'p.'. rtlrl •IY6 L. Sew • III k R Cant CA Ran r •:nw•w■ • rem area rSTCTIOI B i Y r1•• • l 1 n a nfv..-• v CONNECTED MET ON GRADE 11._ pro H •ant. •a i, r' . r,. w • '11 lass an 4•0111-0 •a aMaH1In raY• M Mr ova r •b-. I TO A 70 ACIIOSSPIPE (FLDw. FRDM ONE DIRfCTIDN) ,UL11O. D -p ac.Yl•t.M.w.•towWOattest CI el Hv aII •�/. LIT LE ` Y•.TION•..•tr \�\��.�a \ >,.:',.. .r !EL Gen l\ttl\\sl t1. \ ISrn •I M K • rMlr A1• PAM 4. •ILIeaOIMO \\\V\t\\ ` ea 11 I'2 CO arena MI •\\ ♦ \ ♦ N Ma PLAY • ■la as A{1n art • Miro '\ ` e l rst M W swot it r n e 0.04410 4 San \'-� \\\ 414"U IRlwr SStJ .•MO M. 0 I'wv•w.wurnslru•rvYPIt— lb n M MA a W. WIT AVM P� CA • •v Yaa61n P•Illf lir•alY1p `.IM API ,I Y1•nn •IpWwlag1 a M r1• •v•0A IQs t >I 1it4R MILS XI f `•O II •I1. 1 en MO �+•al t y -a, • raa WS • (�\ O Tema Oa OM F ,( l moll r1•• +�. re •. •a. Intl •F•Nf \i•t•r•MI rW -10 � / `•! II• a I t• •11•11 U ` I••�•a•41 OM •.Y. . •OLU Hy cot 1 •' la 1-�f . • ♦ ♦�♦., i Art} - - tliIn film••d K-./ aia• N N wrl S14E>•t oat •P fMaW �•,._ I+ irzra•Lt \ 1TLE•1cr •n1 unm J 1••t 0QUUIICM I,aeII 'a A \\ \ \ •ar1 \\\ Me `\ �-. •i .• • a• ♦ ' ♦ Ma {1410an.L 11 a a • • - _yy- tF J n51 _ Vial. ..b.-....- -� lV 0 ilai MAIL ♦!E•P CTIOI MA :04.15 >{ N Jim >. v r1.• ""`•"` • �10is?S • �.. •. OW X111404 - E (1U am as CW 1•M ISLET CONNECTED TO A Ya•ty aPt •L n:t}Iwr•iL• wf SS evaul h .ir-E- . WW WS Pc Et 1 A' AM Hy art, 2•t a M WC" All }an METAL PIPE WITHOUT .-♦_1 _•_ DID SECTIONS - kwtiapa:4rwl®Iml tM CtR SC ]11• // p11 8 SE eters (OP WPC ON 8E••r41 O aisle,: [tour.::: �4n onf .awt T...:s :tc uAln5wlruwtouft a. fCtIca a WCM'S. t1 N. M as -an •••I AT m IR)14 ass al •1.•••.••..r crlr'_L MN'M'RPIl4fdYr}I. IE •y'ra::_ 11411fY -> SKEWED CROSS PI PE 1•I •aza en I a• M I. iK loom I r 1 r 1 G ALLOWED WALL T1daotsls PRET AT BOTTOM , OF VERTICAL CURVE a,rnC Lim _ •••• IOW . (FLOW •� action El CLOSE ijSH (fall CRATE FROM TWO QIRFCTIQ(S: $TNDAAO 1FLFT CRATE Computer Fie InfwmotIon inXtl vt•10,•;nl ;;ao• oao Deportment of TronportotMa STANDARD PLAN NO Caloitlr FM InfarMallan �1 ••t R•ri•iwy Colorado Dpartmw t of Transportation STANDARD PLAN NO 14444.- - .. - 9n. oar PO, �n. �_-:. worn" u. me x«.. Viii XI40.h.r•_ METAL PIPE M-603-1 �..-. Ala CEO v.........:•._- s, .,... INLET, TYPE [ 44•604 -ID Lis, Lis, r.. .. .... nr is ® .[0 Ynw ® w owns mu. all i. . _ 4 ••V',• CO •t SI•MIY1E SIICaI No. I 1 ,.I,,. ••� N)-MPYbl f a.• Al >» 1.M Standard Short Ne, I of •T 1.n'�c. a•.•. I I. ® � ••• r. J )::. •. . t > MM of 4.666. 4«.•.1.. 4 um Y •• b. .a, Val ® Project Development Branch IfEf lamas 1•b a M tM anww•a-Mww aR V. .« w.. • Project t Branch S IFt Development Iwrl 041. 4owS•• h.. • A (C w.area. • ha SI .4 •w raw ® YI n1Y• . n' tl... w.•1•. NS DRAWING HAS Cl BEEN PUBLISHED OW WHIR - REFERENCED DRAWINGS DRAWING REVISIONS 1NawUCaNOACONSTRUCTION aIIIPICta. at OUTRIGGER ENERGY BAYOU COMPRESSOR STATION DRAINAGE DETAILS HAS BEEN PREPARED 8r 1AP ENGINEERING t DRAWING NUMBER INLE REV DESCRIPTION BY CHIC APVD DATE CONSTRUCTION ANC FOR (INC Er OIRNI 0 ISSUED FOR CONSTRUCTION LIM JME KW 09/30(14 ECT NAMED W THE b1lF BLOCK SOLELY IN RESPECT Of MET U BLOCK IHE C0NSTRUCTON. OPERATION AND MAINIE NANCE OfZAR �.T.a /0/9976111 ---^••+•-•lr•— ill( FACILITY fIwED IN THE TITLE BLOCS AND SHALL JOB NO 19126 Not BE USED FOR ANY OTHER PURPOSE OR FURNISHED TO ANY OTHER PARTY THE DRAWING NO. 19128-0O3-2012 REV' WITHOUT ExPR(SS CONSENT OF ZAP ENGINEERING & C0NSTRUCION SERVICES. INC _ PLOT SIZE: ANSI 0 SCALE: AS SHOWN O -- �� Applicant Name Weld County Department of Public Works 1111 H Street Greeley, CO 80632 Phone: (970)304-6496 Fax: (970)304-6497 Tammy Zimbelman Company ZAP Engineering Address 333 S. Allison Pkwy, Suite 100 City Lakewood State Co Zip 80226 Business Phone 303-656-4806 E-mail zimbelmant@zapecs.com wsu ivan@outriggerenergy.com Project Location Job Site Address Not assigned yet Section/Township/Range S10- T11N - R64W GRADING PERMIT APPLICATION FORM Property Owner (If different than Applicant) Name Salt Ranch LLC Address 4945 Black Mountain Rd City Wickeburg State AZ Zip 85390 Phone 307-575-0064 E-mail Signature Parcel Number 020710000004 Access Location: Site Accesses onto CR 37 (East, West, North, South) of CR 130 Project Information Is this a Use by Right or Planning and Zoning Case? o Use by Right yPlanning and Zoning Case Planning Land Use Case # (if applicable) USR19-0062 Is this in a Floodplain (verify with Planning Department)? (Yes/No) NO If yes enter your permit number (FHDP) # Description of Work Being Done Site grading for a gas compressor station, access from Weld County Road 57. Construction Start Date 12/18/2019 Acreage Disturbed by Project: X ^'10 Acres Finish Date 1/20/2020 Required Submittal Documents Grading Permit Application Form Plans: Scanned electronic (pdf) or hard copy of 11"x17" set (wet ink stamped and signed by Colorado PE) • Grading Plan — contours labeled with elevations show any ponds or ditches • Erosion & Sediment Control Plan — showing placement of all BMP's to be installed • Typical BMP Installation Details & Notes — for all BMP's to be installed • Proposed Seed Mix Seed Mix 14 lbs pls/ac RECEIVED NOV 132019 Weld County Public Works Dept. X Construction Stormwater permit from Colorado Department of Public Health & Environment (CDPHE) Fee (To Weld County): 1-5 Acres/ $50 5.1 - 20 Acres/$100 20.1 Acres or Greater/$200 + $1 per acre over 20 Pursuant to Weld County Code Section 8-12-60, the Weld County Department of Public Works reserves the right to deny issuance of a Grading Permit to Applicant if the Applicant has not received final approval of any required land use application and/or prior to the satisfaction by Applicant of the terms and conditions of any approved land use application. By submitting this Grading Permit application, the undersigned Applicant, under penalty of perjury, verifies that: (1) they have received all pages of the Grading Permit application; (2) they have read and understand all of the permit requirements and provisions; (3) they have the authority to sign for and bind the Applicant if the Applicant is a corporation or other entity; (4) by virtue of their signature, the Applicant is, upon issuance of a Grading Permit by Weld County, bound by and agrees to comply with all Grading Permit requirements and conditions and all applicable Federal, State, and Weld County statutes, rules, and regulations. Applicant Signature Revised 1/23/2018 Printed Name f ccmnt y Zrrtcitw4tDate i c f 3/19 Weld County Public Works 1111 H Street Greeley, CO 80632 Phone: (970)304-6496 Fax: (970)304-6498 Case Number (USR/SPRiMUSR) USR18-0062 Parcel Number 020710000004 EARLY RELEASE REQUEST OF GRADING PERMIT Weld County's intent is to work with applicants to expedite land use applications as efficiently as possible. The early release of grading permit procedures was developed based on the following goals: El Ensure public safety O Provide consistency between applicants requesting early release of grading permit 7 Provide flexibility in allowing applicants complying with the procedures defined below the opportunity to grade their property in advance of recording the map. The applicant has met the following minimum requirements for early release of grading permit. O All required items in the grading permit are attached El Department of Public Works has on file a final drainage report or accepted drainage narrative, with appropriate drainage calculations and designs The applicant's land use case has been routed to the referral agencies and surrounding property owners and their initial comment period of 28 days has been reviewed by the Planning Department 1 The applicant has reviewed the referral agency comments for the proposed land use set forth in the Application Describe the need for the early release of grading permit: Outrigger al Operating LLC is requesting an early release for grading in order to have the ability to meet contractual obligations with producers. This compressor station will allow gas, from currently shut in wells, to be transported to gas plants for processing and delivery to downstream users. I understand the Department of Planning Services, at its sole discretion, reserves the right to withhold or reject an early release of grading permit. I understand grading prior to formal land use case completion is at my own risk and I accept responsibility for outcomes associated with early release of grading permit. Applicant Signature �� Date Printed Name Company z4P to;men n lOsfier 1/22/2018 Bayou Compressor Station Noise Modeling Report October 4, 2019 Prepared for: Outrigger Energy 1200 Seventeenth Street, Suite 900 Denver, CO 80202 Prepared by: Behrens and Associates, Inc. 13806 Inglewood Avenue Hawthorne California, 90250 ‘t Simon Kim Senior Acoustical Engineer Jason Peetz Engineering Manager Corporate Office: Hawthorne. California Carson. CaliAledo. Texas - Napa California - Longmont. Colorado - McDonald. Pennsylvania 800-679-8633 wwwv.env ironmental-noise-control .com - www.ofri 1 I in gnoisecontrol.com Behrens and Associates, Inc. Environmental Noise Control 1. Introduction AMP N _ The following report provides a noise modeling assessment of the proposed Bayou Compressor Station operated by Outrigger Energy. The proposed Bayou Compressor Station Facility (40° 56' 13.05" N, 104°31' 49.71" W) is located on approximately 1,700 feet west of Weld County Road 57 and approximately 3,680 feet northwest of County Road 130 in Weld County, Colorado. Figure 1-1 identifies the pad location. To assess the predicted noise levels of the proposed operations, manufacturer sound level data of proposed equipment was used when available. File sound level data previously measured and typical of the equipment was used when manufacturer sound level performance data was not available. The equipment sound level data was used to construct a noise model using SoundPLAN 8.0 software. The following is provided in this report: • A brief introduction of the fundamentals of noise. • A review of the applicable CRS 25-12-103 noise standards and Weld County Code ordinance noise limits. • Discussion of noise modeling methodology and results. • An assessment of the predicted noise modeling results Figure 1-1 Proposed Bayou Compressor Station Location Proposed Bayou Compressor Station • Introduction 1 Behrens and Associates, Inc. Environmental Noise Control 2. Noise Fundamentals v\I Sound is most commonly experienced by people as pressure waves passing through air. These rapid fluctuations in air pressure are processed by the human auditory system to produce the sensation of sound. The rate at which sound pressure changes occur is called the frequency. Frequency is usually measured as the number of oscillations per second or Hertz (Hz). Frequencies that can be heard by a healthy human ear range from approximately 20 Hz to 20,000 Hz. Toward the lower end of this range are low-pitched sounds, including those that might be described as a "rumble" or "boom". At the higher end of the range are high-pitched sounds that might be described as a "screech" or "hiss". Environmental noise generally derives, in part, from a combination of distant noise sources. Such sources may include common experiences such as distant traffic, wind in trees, and distant industrial or farming activities. These distant sources create a low-level "background noise" in which no particular individual source is identifiable. Background noise is often relatively constant from moment to moment but varies slowly from hour to hour as natural forces change or as human activity follows its daily cycle. Superimposed on this low-level, slowly varying background noise is a succession of identifiable noisy events of relatively brief duration. These events may include the passing of single -vehicles, aircraft flyovers, screeching of brakes, and other short-term events. The presence of these short-term events causes the noise level to fluctuate. Typical indoor and outdoor A -weighted sound levels are shown in Figure 2-1. COMMON OUTDOOR SOUND LEVELS WP` B-747-200 Takeoff at 2 mi. Gas Lawn Mower at 3 ft. Diesel Truck at 150 ft. DC -9-30 Takeoff at 2 mi. Noisy Urban Daytime B-757 Takeoff at 2 mi. Commercial Area 419 Quiet Urban Daytime Quiet Urban Nighttime Quiet Suburban Nighttime Quiet Rural Nighttime "II •t.. ,• NOISE LEVEL COMMON INDOOR dB (A) SOUND LEVELS 110 Rock Band 100 Inside Subway Train (New York) 90 80 70 60 50 40 30 20 10 Food Blender at 3 ft. Garbage Disposal at 3 ft. Shouting at 3 ft. Vacuum Cleaner atl0ft. Normal Speech at3ft. Large Business Office Dishwasher Next Room Small Theatre, Large Conference Room (Background) Library Bedroom at Night Concert Hall (Background) Broadcast & Recording Studio 0 Threshold of Hearing Figure 2-1 Typical Indoor and Outdoor A -Weighted Sound Levels Noise Fundamentals 2 Behrens and Associates, Inc. Environmental Noise Control 3. Noise Standards N _ 3.1 Colorado Revised Status (CRS) Noise Regulation The modeling analysis was developed to predict operational noise levels at adjacent properties and verify compliance of operations with the CRS 25-12-103 noise standards. The CRS code establishes permissible sound levels by type of property and hours of the day. The measurement location is defined in Section 25-12-103(1) as "Sound levels of noise radiating from a property line at a distance of twenty-five feet or more therefrom in excess of the dB(A) established for the following time periods and zones shall constitute prima facie evidence that such noise is a public nuisance". Based on the specifications of the CRS 25-12-103 code, the noise level limits listed in Table 3-1 may be applicable to the site. Table 3-1 Colorado Revised Statues 25-12-103 (1) — Maximum Permissible Noise Levels Zone Maximum Noise (dBA) 7:00 am to next 7:00 pm Maximum Noise (dBA) 7:00 pm to next 7:00 am Residential 55 dBA 50 dBA Commercial 60 dBA 55 dBA Light Industrial 70 dBA 65 dBA Industrial 80 dBA 75 dBA 3.2 Weld County Code Ordinance The county code establishes permissible sound levels by type of land use and hours of the day. The measurement location is defined in Sec. 14-9-50 as the measurement shall be measured at or within the boundary of the property from which the noise complaint is made. Based on the Weld county code, the noise level limits listed in Table 3-2 may be applicable to the site. Noise Standards 3 Behrens and Associates, Inc. Environmental Noise Control N _ Table 3-2 Weld County Code ARTICLE IX, Sec 14-9-40 — Maximum Permissible Noise Levels Land Use Maximum Noise (dBA) 7:00 am to next 9:00 pm Maximum Noise (dBA) 9:00 pm to next 7:00 am Residential Property or Commercial Area 55 dBA 50 dBA Industrial Area or Construction Activities 80 dBA 75 dBA Nonspecified Areas 55 dBA 50 dBA The modeling analysis was developed to predict operational noise levels at adjacent properties and verify compliance of the proposed operations with the applicable noise standards of Chapter 14, Article IX of The Home Rule Charter for The County of Weld, Colorado per the pending Use By Special Review (USR) permit application. However, at the time of this analysis, The Department of Public Health and Environment for Weld County has not yet provided the developmental standards or prescribed noise level standards for this land use application and therefore the specific allowable noise levels applicable to the site are not known. Noise Standards 4 Behrens and Associates, Inc. Environmental Noise Control 1 4. Proposed Bayou Compressor Station Noise Modeling 4.1 Noise Modeling Methodology The noise modeling was completed with use of three-dimensional computer noise modeling software. All models in this report were developed with SoundPLAN 8.0 software using the ISO 9613-2 standard. Noise levels are predicted based on the locations, noise levels and frequency spectra of the noise sources, and the geometry and reflective properties of the local terrain, buildings and barriers. SoundPLAN 8.0 software simulates light downwind conditions in all directions to ensure conservative assessments. The predicted noise levels represent only the contribution of the proposed compressor station operations and do not include ambient noise or noise from other facilities. Actual field sound level measurements may vary from the modeled noise levels due to other noise sources such as traffic, other facilities, other human activity, or environmental factors. The equipment sound level data used in the proposed Bayou Compressor Station modeling was sourced from equipment manufacturer data and archived file data. If equipment specifications were not available or provided, data from similar or typical equipment was utilized. The modeling results predicted are dependent on equipment and mitigation orientation as indicated in this report. Figure 4-1 shows the proposed Bayou Compressor Station plot plan and mechanical equipment layouts utilized in the study. Table 4-1 lists the equipment included in the modeling based on project designs current to the writing of this report. Table 4-1 Equipment Modeled for Proposed Bayou Compressor Station Quantity Equipment Type Proposed Equipment Data Source 4 4 4 4 1 1 Compressor Engine Compressor Engine Exhaust Cooler Fan Inlet Cooler Fan Out take VRU Combustor Waukesha L7044GS1 Waukesha L7044GSI with Typical Silencer AXH 132F2 AXH 132F2 CAT G3306NA Combustor Manufacturer Data Manufacturer Data Archived Data Archived Data Manufacturer Data Archived Data Source Sound Power Level (Lw dBA) 115.2 99.0 102.1 92.1 102.2 74.6 4.2 Noise Sensitive Receptors The noise sensitive receptors have been chosen to be consistent with the requirements of the CRS 25-12-103 noise standards. The standards indicate that "sound levels of noise radiating from a property line at a distance of twenty- five feet or more therefrom in excess of the dB(A) established for the following time periods and zones shall constitute prima facie evidence that such noise is a public nuisance." As such, receptor locations were chosen at 25 feet from the property boundary of the Wells Ranch Compressor Station to represent potential regulatory measurement points. Figure 4-1 indicates the dBA noise sensitive receptor locations. Figure 4-2 shows the site layout of the proposed Bayou compressor station. Proposed Bayou Compressor Station Noise Modeling 5 Behrens and Associates, Inc. Environmental Noise Control dl3.\ Compliance Assessment Locations Proposed Bayou Compressor Station Site Figure 4-1 Noise Sensitive Receptor Locations (dBA) Proposed Bayou Compressor Station Noise Modeling 6 Behrens and Associates, Inc. Environmental Noise Control Figure 4-2 Proposed Bayou Compressor Station Layout (Drawing No. 601101-001-1000 Rev. C, Date 08/13/19) Proposed Bayou Compressor Station Noise Modeling Behrens and Associates, Inc. Environmental Noise Control 4.3 Noise Modeling Results wit 1 A noise model was created to represent the site operations. The results of the noise modeling are presented in Table 4-2. The locations in the tables correspond to the receptor locations identified in Figure 4-1. The results of the noise modeling are also shown as noise contour maps. Figure 4-3 shows the Noise Contour Map in dBA. The noise contours are provided in 5 dB increments with the color scale indicating the sound level of each contour. The noise modeling included compressors housed in building with an STC rating of 32 and cooler fans located outside building. Receptor Location 1 Location 2 Location 3 Location 4 Table 4-2 Noise Modeling Results (dBA) Location Description Northern Property Line Eastern Property Line Southern Property Line Western Property Line Predicted Operational Noise Level (dBA) 37.9 36.3 37.2 35.5 CRS Allowable Residential Zone Noise Level 55 Day / 50 Night CRS Allowable Commercial Zone Noise Level 60 Day / 55 Night CRS Allowable Light Industrial Zone Noise Level 70 Day / 65 Night Weld County Allowable Noise Level of Residential and Commercial Property 5.5 Day / 50 Night Weld County Allowable Noise Level of Industrial and Construction Property 80 Day / 75 Night The numerical and graphical noise modeling results indicate that the operational noise levels of the proposed Bayou Compressor Station are predicted to comply with the Weld County Code and Colorado Revised Statute noise limits at all receptors. No additional mitigation is required. Proposed Bayou Compressor Station Noise Modeling 8 Behrens and Associates, Inc. Environmental Noise Control Figure 4-3 Operational Noise Contour Map (dBA) Proposed Bayou Compressor Station Noise Modeling Noise Level, dBA = 30 = 35 = 40 = 45 = 50 = 55 = 60 = 65 = 70 = 75 = 80 = 85 = 90 0 700 1400 2100 feet 9 Behrens and Associates, Inc. Environmental Noise Control 5. Conclusion wf 1 N _ A predictive noise model was created to represent the proposed operations at the proposed Bayou Compressor Station operated by Outrigger Energy. The numerical and graphical noise modeling results indicate that the operational noise levels of the proposed Bayou Compressor Station are predicted to comply with the CRS and Weld County code noise limits at all receptor locations. Conclusio Behrens and Associates, Inc. Environmental Noise Control i\AI iv _ Appendix A Glossary of Acoustical Terms Glossary of Acoustical Terms 11 Behrens and Associates, Inc. Environmental Noise Control N _ Ambient Noise The all -encompassing noise associated with a given environment at a specified time, usually a composite of sound from many sources both near and far. Average Sound Level See Equivalent -Continuous Sound Level A -Weighted Decibel Scale The human ear is more sensitive to some sound frequencies than others. It is therefore common practice to apply a filter to measured sound levels to approximate the frequency sensitivity of the human ear. One such filter is called the A -weighted decibel scale which emphasizes sounds between 1,000 and 5,000 Hertz by discounting the frequencies outside of this range. As the human ear is less sensitive to low frequency noise, the A -weighted decibel scale begins to increasingly discount noise below 500 Hertz. Measurements conducted utilizing the A -weighted decibel scale are denoted with an "(A)" or "A" after the decibel abbreviation (dB(A) or dBA). The A -weighted scale is nearly universally used when assessing noise impact on humans. C -Weighted Decibel Scale High level low frequency noise can propagate large distances from its source. Although not always audible, high levels of low frequency noise can induce vibrations in objects or structures which could become evident in ways that might be annoying to humans (e.g., rattling of windows). The C -weighted decibel scale, which was developed to estimate human ear sensitivity to high noise levels, is a flatter filter that does not discount low frequency noise as much as the A -weighted decibel scale. As a result, a C -weighted decibel measurement could be significantly higher than an A -weighted decibel measurement if the noise being measured contains a heavy low frequency content. Measurements conducted utilizing the C -weighted decibel scale are denoted with an "(C)" or "C" after the decibel abbreviation (dB(C) or dBC). C -weighted noise level limits are sometimes included in noise regulations as a way to address low frequency environmental noise issues. Community Noise Equivalent Level (CNEL) A 24 -hour A -weighted average sound level which takes into account the fact that a given level of noise may be more or less tolerable depending on when it occurs. The CNEL measure of noise exposure weights average hourly noise levels by 5 dB for the evening hours (between 7:00 pm and 10:00 pm), and 10 dB between 10:00 pm and 7:00 am, then combines the results with the daytime levels to produce the final CNEL value. It is measured in decibels, dbs. Day -Night Average Sound Level (Ldn) A measure of noise exposure level that is similar to CNEL except that there is no weighting applied to the evening hours of 7:00 pm to 10:00 pm. It is measured in decibels, dB. Glossary of Acoustical Terms 12 Behrens and Associates, Inc. Environmental Noise Control Daytime Average Sound Level The time -averaged A -weighted sound level measured between the hours of 7:00 am to 7:00 pm. It is measured in decibels, dB. Decay Rate The time taken for the sound pressure level at a given frequency to decrease in a room. It is measured in decibels per second, dB/s. Decibel (dB) The basic unit of measurement for sound level. Direct Sound Sound that reaches a given location in a direct line from the source without any reflections. Divergence The spreading of sound waves from a source in a free field, resulting in a reduction in sound pressure level with increasing distance from the source. Energy Basis This refers to the procedure of summing or averaging sound pressure levels on the basis of their squared pressures. This method involves the conversion of decibels to pressures, then performing the necessary arithmetic calculations, and finally changing the pressure back to decibels. Equivalent -Continuous Sound Level (Leq) The average sound level measured over a specified time period. It is a single -number measure of time - varying noise over a specified time period. It is the level of a steady sound that, in a stated time period and at a stated location, has the same A -Weighted sound energy as the time -varying sound. For example, a person who experiences an Leq of 60 dB(A) for a period of 10 minutes standing next to a busy street is exposed to the same amount of sound energy as if he had experienced a constant noise level of 60 dB(A) for 10 minutes rather than the time -varying traffic noise level. It is measured in decibels, dB. Fast Response A setting on the sound level meter that determines how sound levels are averaged over time. A fast sound level is always more strongly influenced by recent sounds, and less influenced by sounds occurring in the distant past, than the corresponding slow sound level. For the same non -steady sound, the maximum fast sound level is generally greater than the corresponding maximum slow sound level. Fast response is typically used to measure impact sound levels. Field Impact Insulation Class (FIIC) A single number rating similar to the impact insulation class except that the impact sound pressure levels are measured in the field. Glossary of Acoustical Terms 13 Behrens and Associates, Inc. Environmental Noise Control v\f Field Sound Transmission Class (FSTC) A single number rating similar to sound transmission class except that the transmission loss values used to derive this class are measured in the field. Flanking Sound Transmission The transmission of sound from a room in which a source is located to an adjacent receiving room by paths other than through the common partition. Also, the diffraction of noise around the ends of a barrier. Frequency The number of oscillations per second of a sound wave Hourly Average Sound Level (HNL) The equivalent -continuous sound level, Leq, over a 1 -hour period. Impact Insulation Class (IIC) A single number rating used to compare the effectiveness of floor/ceiling assemblies in providing reduction of impact -generated sound such as the sound of a person's walking across the upstairs floor. Impact Noise The noise that results when two objects collide. I in pulse Noise Noise of a transient nature due to the sudden impulse of pressure like that created by a gunshot or balloon bursting. Insertion Loss The decrease in sound power level measured at the location of the receiver when an element (e.g., a noise barrier) is inserted in the transmission path between the sound source and the receiver. Inverse Square Law A rule by which the sound intensity varies inversely with the square of the distance from the source. This results in a 6dB decrease in sound pressure level for each doubling of distance from the source. Ln Percentile Sound Level The noise level exceeded for n% of the measurement period where n is between 0.01% and 99.99%. Usually includes a descriptor i.e. A -weighting. Common Ln values include LA 10, LA50, and LA90 levels. LA 10 would represent the A -weighted sound level that is exceeded for 10% of the measurement period. Masking The process by which the threshold of hearing for one sound is raised by the presence of another sound. Maximum Sound Level (Lmax) The greatest sound level measured on a sound level meter during a designated time interval or event. Glossary of Acoustical Terms 14 Behrens and Associates, Inc. Environmental Noise Control NC Curves (Noise Criterion Curves) A system for rating the noisiness of an occupied indoor space. An actual octave -band spectrum is compared with a set of standard NC curves to determine the NC level of the space. Noise Isolation Class (NIC) A single number rating derived from the measured values of noise reduction between two enclosed spaces that are connected by one or more partitions. Unlike STC or NNIC, this rating is not adjusted or normalized to a measured or standard reverberation time. Noise Reduction The difference in sound pressure level between any two points. Noise Reduction Coefficient (NRC) A single number rating of the sound absorption properties of a material. It is the average of the sound absorption coefficients at 250, 500, 1000, and 2000 Hz, rounded to the nearest multiple of 0.05. Normalized Noise Isolation Class (NNIC) A single number rating similar to the noise isolation class except that the measured noise reduction values are normalized to a reverberation time of 0.5 seconds. Octave The frequency interval between two sounds whose frequency ratio is 2. For example, the frequency interval between 500 Hz and 1,000 Hz is one octave. Octave -Band Sound Level For an octave frequency band, the sound pressure level of the sound contained within that band. One -Third Octave The frequency interval between two sounds whose frequency ratio is 2^(1/3). For example, the frequency interval between 200 Hz and 250 Hz is one-third octave. One -Third -Octave -Band Sound Level For a one -third -octave frequency band, the sound pressure level of the sound contained within that band. Outdoor -Indoor Transmission Class (OITC) A single number rating used to compare the sound insulation properties of building fa�ade elements. This rating is designed to correlate with subjective impressions of the ability of facade elements to reduce the overall loudness of ground and air transportation noise. Peak Sound Level (Lpk) The maximum instantaneous sound level during a stated time period or event. Pink Noise Glossary of Acoustical Terms 15 Behrens and Associates, Inc. Environmental Noise Control Noise that has approximately equal intensities at each octave or one -third -octave band. Point Source A source that radiates sound as if from a single point. RC Curves (Room Criterion Curves) A system for rating the noisiness of an occupied indoor space. An actual octave -band spectrum is compared with a set of standard RC curves to determine the RC level of the space. Real -Time Analyzer (RTA) An instrument for the determination of a sound spectrum. Receiver A person (or persons) or equipment which is affected by noise. Reflected Sound Sound that persists in an enclosed space as a result of repeated reflections or scattering. It does not include sound that travels directly from the source without reflections. Reverberation The persistence of a sound in an enclosed or partially enclosed space after the source of the sound has stopped, due to the repeated reflection of the sound waves. Room Absorption The total absorption within a room due to all objects, surfaces and air absorption within the room. It is measured in Sabins or metric Sabins. Slow Response A setting on the sound level meter that determines how measured sound levels are averaged over time. A slow sound level is more influenced by sounds occurring in the distant past that the corresponding fast sound level. Sound A physical disturbance in a medium (e.g., air) that is capable of being detected by the human ear. Sound Absorption Coefficient A measure of the sound -absorptive property of a material. Sound Insulation The capacity of a structure or element to prevent sound from reaching a receiver room either by absorption or reflection. Sound Level Meter (SLM) An instrument used for the measurement of sound level, with a standard frequency -weighting and standard exponentially weighted time averaging. Glossary of Acoustical Terms 16 Behrens and Associates, Inc. Environmental Noise Control Sound Power Level A physical measure of the amount of power a sound source radiates into the surrounding air. It is measured in decibels. Sound Pressure Level A physical measure of the magnitude of a sound. It is related to the sound's energy. The terms sound pressure level and sound level are often used interchangeably. Sound Transmission Class. (STC) A single number rating used to compare the sound insulation properties of walls, floors, ceilings, windows, or doors. This rating is designed to correlate with subjective impressions of the ability of building elements to reduce the overall loudness of speech, radio, television, and similar noise sources in offices and buildings. Source Room A room that contains a noise source or sources Spectrum The spectrum of a sound wave is a description of its resolution into components, each of different frequency and usually different amplitude. Tapping Machine A device used in rating different floor constructions against impacts. It produces a series of impacts on the floor under test. 10 times per second. Tone A sound with a distinct pitch Transmission Loss (TL) A property of a material or structure describing its ability to reduce the transmission of sound at a particular frequency from one space to another. The higher the TL value the more effective the material or structure is in reducing sound between two spaces. It is measured in decibels. White Noise Noise that has approximately equal intensities at all frequencies. Windscreen A porous covering for a microphone, designed to reduce the noise generated by the passage of wind over the microphone. Glossary of Acoustical Terms 17 Behrens and Associates, Inc. Environmental Noise Control Appendix B Typical Exhaust Silencer Attenuation Typical Exhaust Silencer Attenuation 18 Behrens and Associates, Inc. Environmental Noise Control C 0 Attenuation for Hospital Plus Chamber Type Silencer: Altt ii; ntioii (dB) r3 60 5) 4) 3? 21.3 10 1) 31 a 63 125 250 507 1033 2000 40)O 8COD Octave Band Center Frequency (hz) 12 18" Typical Exhaust Silencer Attenuation 19 Behrens and Associates, Inc. Environmental Noise Control August 23, 2019 Outrigger Energy 1200 Seventeenth Street Suite 900 Denver, CO 80202 Attention: Will Sullivan Subject: Ambient Sound Level Report Re: Bayou Compressor Station Dear Mr. Sullivan: Per your request, an ambient sound level survey was performed for the proposed Bayou Compressor Station in Grover, Colorado from Friday, August 16 to Monday, August 19, 2019 to measure and document the ambient sound levels near the site. The following report documents our findings. Ambient Sound Level Survey An ambient survey, including A -weighted dB(A) and C -weighted dB(C) sound pressure level data, was performed for the proposed Bayou Compressor Station to measure and document ambient sound levels for hourly, 15 -minute and daytime/nighttime averages. Per ASTM E1014- 84 7.1 No measurements shall be made when steady wind speeds exceed 20 km/h (12 mph). The daytime and nighttime sound level averages in Table 1 omit the data collected where the wind speed exceeded 12 miles per hour. Attachments 2 through 5 include all the unfiltered data. Sound Measurement Instrumentation The instrumentation used for the monitoring location was a Svantek Model 971 integrating and logging sound level meter, which was calibrated prior to deployment. The metering system was approximately 4 feet above ground level per ASTM E1014-84 8.1.7 guidelines and in a locked box for security. Attachment 1 shows an aerial view of the monitoring locations while Attachment 2 shows the location of the deployed monitor. The measured noise levels are presented graphically in Attachments 3 & 4 and in tabulated form in Attachment 5. The ambient noise levels were used to determine the typical daytime (7am to 7pm) and nighttime (7pm to 7am) averages at the monitored location. The daytime and nighttime logarithm le averages were calculated using the 15 -Minute noise levels measured at the location. The calculated ambient average daytime and nighttime noise levels are summarized in Table 1. Corporate Office: Hawthorne, California Carson, California - Aledo, Texas - Napa, California -- Longmont, Colorado -- McDonald, Pennsylvania - Calgary, Canada Phone 800-679-8633 — Fax 310-331-1538 www.environmental-noise-control.com — www.drillingnoisecontrol.com Behrens and Associates, Inc. Environmental Noise Control Table 1 Average Daytime and Nighttime Ambient Noise Levels Outrigger Energy - Bayou Compressor Station Day " Daytime Leq Ambient Noise Levels Nighttime Leq Ambient Noise Levels dBA dBC dBA dBC 1* 66.0 83.6 54.0 72.7 2 59.4 83.0 55.7 79.2 3 58.1 79.9 55.7 66.7 4** 61.6 82.3 Overall Lcq 62.4 82.4 55.2 75.5 *Day 1 Daytime is an Leq (logarithmic average) from 12pm until 7pm. *Day 4 Daytime is an Leq (logarithmic average) from 7am until 12pm. Best regards. Colin M. Drolshagen Lead Acoustical Technician Corporate Office: Hawthorne. California Carson, California - Aledo, Texas - Napa. California - Longmont, Colorado - McDonald. Pennsylvania - Calgary, Canada Phone 800-679-8633 — Fax 310-331-1538 www.environmental-noise-control.com www.drillingnoisecontrol.com Behrens and Associates, Inc. Environmental Noise Control Sound Level (1 -hour Leq) 110 105 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 2 a a 0 9 N N a a a 0 0 0 d eD 00 S C. 0 0 C e4 Outrigger Energy Bayou Compressor Station Ambient Sound Level Survey 2 2 2 0 S S S N t.0 00 2 2 2 Q a a 0 00 0 00 ai N N el el 2 0- a 0 0 00 00 e -e C S 0 N 2 a Q 0 g 0 d eD Oo 2 a August 16 - August 19, 2019 Attachment 3 Q a QQ. a a. FL 0 9 9 0 0 0 O N Al 4 kD CO e l e"1 2 a O O dBC dBA Wind eto th C O S 2 2 2 0 8 8 8 N Q 40 00 Behrens and Associates, Inc. Environmental Noise Control Sound Level (15 -minute Leg) 110 105 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Outrigger Energy Bayou Compressor Station Ambient Sound Level Survey a a a a a a a a Q Q C Q Q Q Q Q a a a a Cl- a a Cl- 4 Q Q Q Q Q Q Q 0- g o 0 00 0$ O en O Oo r 8 8 8 M e ran o M o Mom $ 8 M$ Ian o M N r-1 M 4 �D f� Q1 O N N M Cft CD GO Q1 rl N N M Lf1 ti 00 Cr; r 1 N N M t!1 iD 00 Q1 c-•1 N - e-i '-i el rl r-) el rl 1" 1 August 16 - August 19, 2019 Attachment 4 1! 2 2 2 2 a a a a 8 rn o cf1 tD 00 G Q O dBC dBA Wind 2 2 2 2 2 2 < < < < a a 8 8 8 M M • ►r▪ 1cia0 Q1 50 45 U. 30 20 15 10 c) 0 G a 0 Behrens and Associates, Inc. Environmental Noise Control w\I 1 N _ Outrigger Energy - Bayou Compressor Station Hourly Leg Time dBA dBC lime dBA dBC 12.00 PM 60 1 73 I Sun 18 -Aug 59 6 75 4 1 :00 PM 58.2 76 8 1:00 AM 57 9 815 2.00 PM 60.5 78.9 2.00 AM 55.3 82.0 3:00 PM 55 8 70 3 3:00 AM 57 5 79.6 4-00 PM 56 7 82 I 4.00 AM 55 3 72.0 5.00 PM 73 8 90 5 5.00 AM 43 1 57.5 6:00 PM 55.3 81.5 6 00 AM 30 3 52.3 7:00 PM 57 6 70.4 7.00 AM 56.5 69.9 8:00 PM 57 0 77 7 8 00 AM 60 6 74.8 9:00 PM 57 7 80 6 9.00 AM 58.5 76.4 10:00 PM 52.5 71 6 1O00 AM 56.2 78.4 1 1 :00 PM 55.9 64.8 1 1 :00 AM 57.8 80.7 Sat I7 -Aug 47.4 58.2 12:00 PM 60.2 82.3 1:00 AM 53 8 64 6 1.00 PM 59 9 84.0 200 AM 523 616 2.00 PM 602 83.2 3:00 AM 540 639 300 PM 589 81.5 4:00 AM 48.9 68 7 4.00 PM 55 I 75.4 5 00 AM 41 2 68 4 5.00 PM 51 7 76.8 6-00 AM 39 6 57 9 6.00 PM 50 9 76.3 7.00 AM 578 71 I 700 PM 578 69.3 8:00 AM 59.6 80.0 8:00 PM 57 4 66.5 9:00 AM 56.0 80.4 9:00 PM 50.4 60.4 10:00 AM 58.8 837 10,00 PM 335 593 1 1 00 AM 62 7 85 7 1 1 :00 PM 60 4 71.3 12:00 PM 68.4 94 1 Mon 19 -Aug 55 2 66.6 1 :00 PM 68.4 93.1 I :00 AM 56.1 65.5 2:00 PM 71 7 96.8 2.00 AM 56 2 67.7 300 PM 787 1017 300 AM 588 690 4:00 PM 71 8 96.2 4:00 AM 47 1 61 .9 5:00 PM 59.2 87.5 5:00 AM 29.8 58.5 6.00 PM 804 1026 600 AM 523 647 7:00 PM 67 7 93.0 7.00 AM 60 3 74 8 8.00 PM 54 3 82.9 8.00 AM 62 5 79.0 9:00 PM 57 8 78 7 9.00 AM 58 6 85.9 10:00 PM 53.4 79.5 10:00 AM 60.5 86.1 11.00 PM 53.6 789 11:00 AM 638 81.6 Attachment 5 Pawnee Fire Protection District PO Box 66 Grover, Colorado 80729 To Whom It May Concern, Sept 5t", 2019 I am contacting Pawnee Volunteer Fire Department on behalf of my client, Outrigger DJ Operating, to give notification that they are in the process of permitting a compressor station in the Pawnee Fire Protection District area. The location of this station is approximately one half mile north of CR 130 and approximately 1,000 feet west of CR 57. See enclosed map. This compressor station is being permitted according to Weld County USR regulations. One of these regulations is to notify the local fire department. I respectfully request a response to this letter, acknowledging that it was received. If the Pawnee Volunteer Fire Department has any questions or needs additional information, please let me know. I have included my mailing address, email address, phone number and fax number. Please communicate by whichever means is the most convenient. Thank you, Tammy Zimbelman Project Manager ZAP Engineering 333 S. Allison Parkway Lakewood, CO 80226 zimbelmant@zapecs.com Phone #303-656-4806 Fax #720-529-4437 EMERGENCY ACTION PLAN OUTRIGGER DJ OPERATING LLC / BAYOU COMPRESSOR STATION 720-361-2580 AUGUST 30, 2019 BAYOU COMPRESSOR STATION- S10 T11N R64W Emergency Action Plan OUTRIGGER 0 ENERGY T Topic: Emergency Planning & Response Rev. No.: 0 Date: August 30, 2019 Page 1 of 2 FACILITY OVERVIEW The Bayou Compressor Station is a 25 MMSCFD unmanned gas compressor station. Incoming gas and liquids will be separated in the inlet slug catcher. The low pressure liquids will be sent to API tanks and trucked off site. The gas will be routed to compression and then to a dehydration unit. The treated gas is metered and discharged from the facility into a pipeline. Water is removed from the compressed gas during the treating process. The removed water is sent to API tanks and trucked off -site for disposal. Flammable gases and liquified -petroleum -gases (LPGs) are the primary chemical hazards associated with the compressor station. 1. Outrigger DJ Operating LLC - Bayou Compressor Station 2. Location: 510, T11N, R64W; GPS Coordinates: Lat: 40°56'12.22"N, Long: 104°31'48.73"W 3. Emergency Telephone Numbers: *CALL 911 in case of emergency 3.1. Facility Primary, Andrew Perdue 3.2. Facility Secondary, Trent Taylor 3.3. Alternate, Will Sullivan 720-361-2580 720-361-2575 720-361-2571 Cell: 720-244-0456 Cell: 469-387-4014 Cell: 406-498-5522 Fire District: Pawnee Fire Department 970-895-2237 Ambulance Service: 970-663-6025 Thompson Valley EMS North Colorado Medical Center: 970-810-4121 4. Agency Notification Non -Emergency 4.1. Pawnee Fire Department 4.2. Law Enforcement — Sheriff 4.3. Colorado State Patrol 970-895-2237 970-356-4015 970-506-4999 5. Surrounding Occupancies & Land Use — parcel is surrounded by farm land and natural grasses, there is an unmanned well pad site approximately a 1/2 mile north 6. Personal Protective Equipment Available — When the facility is operational, all personnel on site will be required to wear hard hats, FR clothing, steel toed boots, and eye protection. Hearing protection may be required in certain areas. 7. Location of Emergency Equipment & Supplies — Fire extinguishers will be placed strategically throughout the site, buildings will have gas detection and fire eyes, a first aid kit will be in the office. 1 Emergency Action Plan OUTRIGGER ENERGY Topic: Emergency Planning & Response Rev. No.: 0 Date: August 30, 2019 Page 2 of 2 8. Location & Types of Water Supplies - This will be an unmanned site with no permanent water supply. 9. Transportation Routes — Access to the site will be from the south, CR 128, with traffic heading north on CR 57 to the entrance of the station. 10. Action Items and Response 10.1. Emergency Response — Remote shutdown of the facility is the response for any emergency requiring a shutdown or isolation of incoming gas. These emergencies may be detected by instrumentation/alarms or Outrigger Energy personnel. 10.2. Large Liquid Release — The emergency response to a spill of one of these liquids would be to first stop the flow if possible. Try to control the liquids which were spilled such as using dirt to dike the area in front of the spill. If the spill is condensate or LPG do not do anything which might cause a spark. Use pumps or a vacuum truck to remove as much liquid as possible. Remediate the soil as soon as possible to prevent the liquids from going any deeper in the soil. In case of exposure to any of these liquids see the proper Safety Data Sheet (SDS) for health effects and emergency procedures. Safety Data Sheets (SDS) for all materials located in the Facility can be found in the SDS manual, located at the Outrigger Energy Bayou Compressor Station Office. 10.3. Large Gas Release - For large gas releases not associated with normal operations, call 911, isolate the area in question and blow down the pressure. Record all details pertaining to the incident. Notifications should proceed as in any other emergency. 10.4. Fire - At the scene of a fire, Outrigger Energy employee shall take every corrective action necessary to protect life first and then property from danger. The employee shall assess the danger to public, surrounding building occupants, and property by use of visual observance, leak detectors, pressure gauges, etc. Call 911. Evacuate or assist all persons to safety. Blockade area if necessary and maintain communication with fire, police and other public officials that are on the scene. 11. Coordination with First Responder Agencies: When at the scene of an emergency, the most senior Outrigger Energy representative shall develop a tentative course of action. Actions should be directed toward protecting people first, then property. First responders at the scene will want to help Outrigger Energy personnel in coping with the situation they are in. However, during all circumstances, first responders are to remain outside of the facility limits until approved to enter by an Outrigger supervisor on scene. 12. Safety and Training Review: Outrigger employees are trained for emergency response upon hiring and annually thereafter. Outrigger will conduct annual emergency shutdown tests at the Bayou Compressor Station. 2 COLORADO Department of Public Health b Environment Facility Activity : Disturbed Acres: Facility Located at: CERTIFICATION TO DISCHARGE UNDER CDPS GENERAL PERMIT COR400000 STORMWATER ASSOCIATED WITH CONSTRUCTION ACTIVITIES Certification Number: COR403414 This Certification to Discharge specifically authorizes: Owner Outrigger DJ Operating LLC Operator Outrigger DJ Operating LLC to discharge stormwater from the facility identified as Outrigger DJ Operating Project To the waters of the State of Colorado, including, but not limited to: to Crow Creek to South Platte River Pipeline and utilities 50000 acres CR 95 and CR 96 Briggsdale CO 80611 Weld County Latitude 40.68352 Longitude -104.13011 Specific Information Covering North Central Weld County (if applicable): Certification is issued 4/1 /2019 Certification is effective 4/1/2019 Expiration date of general permit : 3/31/2024 This certification under the permit requires that specific actions be performed at designated times. The certification holder is legally obligated to comply with all terms and conditions of the permit. This certification was approved by: Meg Parish, Unit Manager Permits Section Water Quality Control Division 4300 Cherry Creek Drive South, Denver, CO 80246 303-692-3500 www.colorado.gov/cdphe/wgcd COLORADO Department of Public Health & Environment Dedicated to protecting and improving the health and environment of the people of Colorado Owner Andrew Perdue, Sr PM Outrigger DJ Operating LLC 1200 17 St Ste 900 Denver, Denver 80202 Operator Andrew Perdue, Sr PM Outrigger DJ Operating LLC 1200 17 St Ste 900 Denver, CO 80202 DATE: 3/18/2019 MEMO RE: Renewal of Construction Stormwater Certification, Colorado Discharge Permit System Permit No., COR400000, Certification Number: COR403414 formerly COR03T543 DIVISION CONTACTS: Joseph Sturgeon, 303-691-4019, Joseph.Sturgeon@state.co.us ATTACHMENTS: Certification COR403414, COR400000 General Permit The Water Quality Control Division (the Division) has reviewed the application submitted for the Outrigger DJ Operating Project facility and determined that it qualifies for coverage under the CDPS General Permit for Stormwater Discharges Associated with Construction Activities (the permit). Enclosed please find a copy of the permit certification, which was issued under the Colorado Water Quality Control Act. FEE INFORMATION: 50000 acres Beginning July 1, 2019 an annual fee of S 540 category 7, subcat II -K Stormwater Construction 540 per CRS 25-8-502] will be assessed and invoiced every July for as tong as the permit certification is in effect. It is the responsibility of the permittee to submit a termination application when the permit is no longer needed. Fees are assessed and invoiced for every permit that is active July 1 of the fiscal year. Permits for which termination applications are received by June 30 of the current fiscal year will not be invoiced for the new fiscal year. CERTIFICATION RECORDS INFORMATION: The following information is what the Division records show for this certification. For any changes to Contacts - Owner, Operator, Facility, or Billing - a "Notice of Change of Contacts form" must be managed through the Division's new platform called the Colorado Environmental Online Services (CEOS). The Notice of Change of Contacts form must be electronically signed by both the owner and the operator. Facility: Outrigger DJ Operating Project WeldCounty Construction Activities Pipeline and utilities Owner and Operator (receives all legal documentation pertaining to the permit certification): Andrew Perdue, Sr PM Phone number: 720-361-2580 Outrigger DJ Operating LLC Email: aperdue@outriggerenergy.com 1200 17 St Ste 900 Denver, Denver 80202 Facility Contact (contacted for general inquiries regarding the facility): Cody Kerrigan,Engr Mgr Phone number: 720-361-2551 Outrigger DJ Operating LLC Email: ckerrigan@outriggerenergy.com 1200 17 St Ste 900 Denver, CO 80202 Billing Contact (receives the invoice pertaining to the permit certification): Marshall Olson, VP Accounting Phone number: 720-368-7309 Outrigger DJ Operating LLC Email: molson@outriggerenergy.com 1200 17 St Ste 900 Denver, CO 80202 4300 Cherry Creek Drive South, Denver, CO 80246 303-6923500 www.colorado.gov/cdphe/wgcd Registration Number Status :tile Number Owner Name Latitude/Longitude Structure City/State Overall Height Abe 1025891 ::ob4? 122211,12g 1306537 litter I A !sea% rein . N CorwauWoltcna Conwassion Constructed Corstruct 41031245 2,1102168 CCATT LLC held County Government Constructed 40759310 tndustrial7bwn and Winless, tic Granted antenna Structure Registration 41102171 Weld County Government 40-44.29.3N 103.59.25.1W GROVER.CO 40-54-47.0N 104.05-24.0W weld county. CO 40-51-51.014 104-13-42.9W 40.54-47.0N 101.05-23.8W Grover (Downtown), CO Grover, CO 129.5 SO 55)4 56.9 ; ur-'.Jr•- I Lc, -IQ •.,'..rat I tQ.1M-i9Trrs I !;ni' i\L i'ii i? t SC • fl •al •• X31 sn,c. %SR-GIS k UKA 'omit El' &et JP IQ Rt:._a © CR 130 intr. Ita IYMI, a IN t • te.. ' 'IJ OW" Or Iy (Oat, IA.:I :..w', IS 1M Sawa Map Salellhe _vrae Towers located near Grover, Colorado. I a n. 9 tOM'.e rCtI • •n..M. VP •1: !a\., p.._ 9 L 1 It NO ••••'• it lie (J._ 4e Industrial tower.•.'„. & Wireless, LLC 0 Compressor station site is approximately % mile west of CR 57 from approximately %2 mile north of CR 130. Display- Bat< vs... • Registration Number I 1025892 Status Constructed rile Plumber Owner Name 41031244 2 1:32914 Cr, -tiled 40332629 Granted 40583721 La Fames Broadcasting. tLC 4 326:'44 G'4rteC 40591863 S 1261745 Granted AOS83860 lA FAMILIA BROADCASTING,LLC. 6 41068960 3 1261725 CCATT LLC Tone'Coen West Coast. LLC La Farndia Broadcasting, ILC 1242941 Cancelled xcel Energy Services Inc- latitude/longitude Structure City/State Overall Height Above Ground (Act) 40-52.18,1N 104.46.42.3W 40 54.25.2N 104-55-S4 9W 40.49.59.0N 104-48.00.0W 40.49.59.0N 1C4.47.55.0W 40.49•S9.ON 104-47-50.0W 4059-52.2N 104.48-38.1W CA RR. CO 126.5 Cart CO crr CO CARR. CO 118.0 1:8 U CARR CO 118.0 Cart CO 45� Antenna Structure Registration ASR-GIS tl!asa In In In I AC rStreet Map 11 (9-nTr •t. Satellite Terrain Towers located near Carr, Colorado. CCATT, LLC Compressor station site is approximately 1/4 mile west of CR 57 from approximately 1/2 mile north of CR 130. O CR 130 teMte ID Vr 10/11/2019 Google Maps Go gle Maps Imagery ©2019 Google, Imagery ©2019 TerraMetrics, Map data ©2019 2 mi Measure distance Total distance: 13.73 mi (22.09 km) https //www.google.com/maps/@40.902945,-104.629002,19337m/data=!3m1 !1e3 1/1 Google Maps 10/11/2019 Imagery ©2019 Google, Imagery ©2019 TerraMetrics, Map data ©2019 2 nil Go, gle Maps Tower near Grover WYOMING cm ORADO Measure distance Total distance: 16.58 mi (26.68 km) https://www.google.com/maps/©40.9024603,-104.281811,27133m/data=!3m1 !1 e3 1/1 TRAFFIC CONTROL PLAN ♦ = Existing Access A= Proposed Access T N NON-EXISTANT) U, Description of Work or Reason for Permit - An access permit will be applied for in order to access the Bayou Compressor Station. WCR 132 (UNMAINTAINED) 0 NON-EXISTANT SITE WCR 130 - NON-EXISTANT WEST OF CR 57 J U, cc V 3 2500' from intersection to access point WCR 130 - MAINTAINED EAST OF CR 57 WCR 128 - Access to site will be from the west side of CR 57, approximately 2500' north of CR 130 - 100% of the traffic will be traveling north on CR 57 from CR 128. - ROAD WORK AHEAD signs will be used during construction of the access point Secretary of State Wyoming Secretary of State 2020 Carey Avenue Suite 700 Cheyenne, WY 82002-0020 Ph. 307-777-7311 For Office Use Only Ed Murray, WY Secretary of State FILED: Jan 18 2017 9:15AM Original ID: 2017-000739364 Limited Liability Company Articles of Organization I. The name of the limited liability company is: Salt Ranch LLC II. The name and physical address of the registered agent of the limited liability company is: BAILEY I STOCK I HARMON I COTTAM P.C. 221 E 21st St Cheyenne, WY 82001 III. The mailing address of the limited liability company is: 4945 Black Mountain Rd. Wickenburg, AZ 85390 IV. The principal office address of the limited liability company is: 4945 Black Mountain Rd. Wickenburg, AZ 85390 V. The organizer of the limited liability company is: Bailey I Stock I Harmon I Cottam P.C. 221 E. 21st Street. Cheyenne. WY 82001 Signature: Print Name: Title: Email: Daytime Phone #: Ronald J. Lopez Ronald J. Lopez Shareholder rjl@bshclawgroup.com (307) 638-7745 Date: 01/18/2017 Page 1 of 4 Secretary of State Wyoming Secretary of State 2020 Carey Avenue Suite 700 Cheyenne, WY 82002-0020 Ph. 307-777-7311 Eg I am the person whose signature appears on the filing; that I am authorized to file these documents on behalf of the business entity to which they pertain; and that the information I am submitting is true and correct to the best of my knowledge. I am filing in accordance with the provisions of the Wyoming Limited Liability Company Act, (W.S. 17-29-101 through 17-29-1105) and Registered Offices and Agents Act (W.S. 17-28-101 through 17-28-111). I understand that the information submitted electronically by me will be used to generate Articles of Organization that will be filed with the Wyoming Secretary of State. I intend and agree that the electronic submission of the information set forth herein constitutes my signature for this filing. I have conducted the appropriate name searches to ensure compliance with W.S. 17-16-401. Notice Regarding False Filings: Filing a false document could result in criminal penalty and prosecution pursuant to W.S. 6-5-308. W.S. 6-5-308. Penalty for filing false document. (a) A person commits a felony punishable by imprisonment for not more than two (2) years, a fine of not more than two thousand dollars ($2,000.00), or both, if he files with the secretary of state and willfully or knowingly: (i) Falsifies, conceals or covers up by any trick, scheme or device a material fact; (ii) Makes any materially false, fictitious or fraudulent statement or representation; or (iii) Makes or uses any false writing or document knowing the same to contain any materially false, fictitious or fraudulent statement or entry. I acknowledge having read W.S. 6-5-308. Filer is: ❑ An Individual I An Organization The Wyoming Secretary of State requires a natural person to sign on behalf of a business entity acting as an incorporator or organizer. The following individual is signing on behalf of all Organizers or Incorporators. Filer Information: By submitting this form I agree and accept this electronic filing as legal submission of my Articles of Organization. Signature: Ronald J. Lopez Print Name: Ronald J. Lopez Title: Shareholder Email: rjl@bshclawgroup.com Daytime Phone #: (307) 638-7745 Date: 01/18/2017 Page 2 of 4 Secretary of State Wyoming Secretary of State 2020 Carey Avenue Suite 700 Cheyenne, WY 82002-0020 Ph. 307-777-7311 Consent to Appointment by Registered Agent BAILEY I STOCK I HARMON I COTTAM P.C.. whose registered office is located at 221 E 21st St, Cheyenne, WY 82001, voluntarily consented to serve as the registered agent for Salt Ranch LLC and has certified they are in compliance with the requirements of W.S. 17-28-101 through W.S. 17-28-111. I have obtained a signed and dated statement by the registered agent in which they voluntarily consent to appointment for this entity. Signature: Print Name: Title: Email: Daytime Phone #: Ronald J. Lopez Ronald J. Lopez Shareholder rjl@bshclawgroup.com (307) 638-7745 Date: 01/18/2017 Page 3 of 4 Filed Date: 01/18/2017 STATE OF WYOMING Office of the Secretary of State I, ED MURRAY, Secretary of State of the State of Wyoming, do hereby certify that the filing requirements for the issuance of this certificate have been fulfilled. CERTIFICATE OF ORGANIZATION Salt Ranch LLC I have affixed hereto the Great Seal of the State of Wyoming and duly executed this official certificate at Cheyenne. Wyoming on this 18th day of January, 2017 at 9:15 AM. Remainder intentionally left blank. Filed Online By: Ronald J. Lopez on 01/18/2017 Page 4of4 Hello