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HomeMy WebLinkAbout20232863.tiffCode Change. MEMORANDUM To Weld County Planning Commission From Diana Aungst, Planner III Subject ORD2023-12, Floodplain Management Ordinance Date September 5, 2023 Weld County is required by the Colorado Conservation Water Board (CWCB) and Federal Emergency Management Agency (FEMA) to adopt code language that accepts the new floodplain maps that will be effective on November 30, 2023 The Code that adopts these new floodplain maps are required to have an effective date prior to November 30, 2023, which is shown as a change in Section 23-11-230 of the attached draft resolution Other changes in the resolution include a revision to the allow septic systems in the floodplain under when no other options are available Chapter 23 Floodplain Management Ordinance now references Chapter 30 (Weld County Department of Public Health and Environment On -Site Wastewater Treatment System Regulations) The remainder of these code changes are housekeeping items to clean up and add clarification to the code Recommendation. Staff recommends adoption of the proposed ordinance Background: The 2013 flood event 'caused widespread damage and changes along the rivers throughout the County as well as other areas in the state In response, the State of Colorado funded the Colorado Hazard Mapping Program (CHAMP) that updated regulatory floodplain maps for the most affected rivers The purpose of CHAMP is to study the flooding sources in the state and revise, if necessary, the floodplains associated with these flooding sources The primary flooding sources in Weld County are the major rivers Big Thompson, Little Thompson, Saint Vrain, Boulder Creek, South Platte Meetings with CWCB and CH2MHill started in 2015 These meeting on the various rivers continued periodically to keep Weld County up to date on the studies In 2018 Weld County hosted public outreach meetings in order to contact all affected property owners The first outreach meeting was held on May 10, 2018 These meetings, hosted by Weld County, provided the opportunity for affected property owners to ask questions about how the change to the floodplain boundaries would affect their land and structures including insurance on said structures Weld County hosted nine (9) of these outreach meetings in various places depending on the river being studied i e for those who own property along the Cache la Poudre River the meetings were held 2023-2863 Page 2 of 2 ORD2023-12 Floodplam Management Ordinance at the Administration Building, for those who own property along the South Platte River meetings were held in Longmont at the South West Service Center, Fort Lupton's Recreational Center, Kersey's Recreational Center, and the Administration Building in Greeley The first Preliminary Maps were issued September 17, 2020, and the County has been utilizing the floodplain boundaries as shown on the Preliminary Maps as Best Available Information in review of all floodplain permits to ensure that any structures built will meet floodplain requirements in the future Before the Weld County, Colorado, Planning Commission Resolution of Recommendation to the Board of County Commissioners Moved by Skip Holland, that the following resolution be introduced for passage by the Weld County Planning Commission Be it resolved by the Weld County Planning Commission that the application for Case Number Presented by Request Ordinance 2023-12 Tom Parko/Diana Aungst In the Matter of Repealing and Reenacting, with Amendments, Chapter 23 Zoning of the Weld County Code (Floodplain Regulations) be recommended favorably to the Board of County Commissioners Motion seconded by Pamela Edens VOTE For Passage Elijah Hatch Skip Holland Pamela Edens Michael Wailes Michael Palizzi Shana Morgan Virginia Gudegahn Barney Hammond Against Passage Absent Butch White The Chair declared the resolution passed and ordered that a certified copy be forwarded with the file of this case to the Board of County Commissioners for further proceedings Certification of Copy I, Kristine Ranslem, Recording Secretary for the Weld County Planning Commission, do hereby certify that the above and foregoing resolution is a true copy of the resolution of the Planning Commission of Weld County, Colorado, adopted on September 5, 2023 Dated the 5th of September, 2023 6,(-6 ini 'fen, Kristine Ranslem Secretary CHAPTER 23 - Zoning ARTICLE I General Provisions Sec. 23-1-90. Definitions. The following specific words and phrases, when appearing in this Chapter in uppercase letters, shall have the meanings stated in this Section: BASE FLOOD: The FLOOD having a one percent (1%) chance of being equaled or exceeded in any given year. This term is used in the NFIP to indicate the minimum level of flooding to be used by a community in its floodplain management regulations. CODE OF FEDERAL REGULATIONS (CFR): The codification of the general and permanent Rules published in the Federal Register by the executive departments and agencies of the Federal Government. It is divided into 50 titles that represent broad areas subject to Federal regulation. DEVELOPMENT: The placement, construction, erection, reconstruction, movement and/or alteration of BUILDINGS and/or other STRUCTURES, the placement of paved areas, drainage improvements or alterations on the historic flow of drainage patterns or amounts, and the placement of lighting and/or other appurtenances related to any and all USES exckiding Olt AND GAS FACILITIES. Includes any man-made change to improved or unimproved real estate, including but not limited to BUILDINGS or other STRUCTURES, MINING, dredging, filling, grading, paving, excavation or drilling operations or storage of equipment or materials. DFIRM DATABASE: Database (usually spreadsheets containing data and analyses that accompany DFIRMs). The FEMA Mapping Specifications and Guidelines outline requirements for the development and maintenance of DFIRM databases. DIGITAL FLOOD INSURANCE RATE MAP (DFIRM): FEMA digital floodplain map. These digital maps serve as -regulatory floodplain maps" for insurance and floodplain management purposes. ELEVATED BUILDING: A BUILDING without a BASEMENT and: a. Built, in the case of a BUILDING in Zones A, A1-30, AE, A. A99, AO. AH, and AO, B7---C-X and D, to have the top of the ELEVATED floor above the ground level by means of pilings, columns (posts and piers) or shear walls parallel to the floor of the water; and [b.- no change] In the case of Zones A, A1-30, AE, A, A99, AO, AH, and AO B, C, X and D, ELEVATED BUILDING also includes a BUILDING ELEVATED by means of FILL or solid foundation perimeter walls with openings sufficient to facilitate the unimpeded movement of FLOOD waters. FLOOD BOUNDARY AND FL A Y MAP (FB-FM): The official map on which FEMA has delineated SPECIAL FLOOD HAZARD- AREAS, FL YS and the risk premium zones applicable to the COUNTY. FLOOD HAZARD BOUNDARY MAP (FHBM): FLOOD map of the COUNTY issued by FEMA, where the boundaries of the FLOOD, mudflow and related erosion areas having special hazards have been designated. FLOOD -VENTED STRUCTURES: an orifice in an enclosed STRUCTURE intended to allow the free passage of water between the interior and exterior to reduce potential damage to BUILDINGS ELEVATED on CRAWLSPACES. FLOOD ZONES: The FEMA designated FLOOD ZONES are as follows: a. Zone A (Approximate 100 -YEAR FLOODPLAIN) is a SFHA with a one percent (1%) or greater chance of FLOODING each year and where, in most cases, BFEs and FLOOD hazard factors have not been determined by FEMA. b. Zones A1 -A30 and AE (100 -YEAR FLOODPLAIN and FLOODWAY) are SFHAs with a one percent (1%) or greater chance of FLOODING each year and where BFEs and FLOOD hazard factors have been determined by FEMA. c. Zone AO is a SFHA with a one percent (1%) or greater chance of shallow FLOODING each year, usually in the form of sheet flow with an average depth between one (1) and three (3) feet. d. Zone AH is a SFHA with a one percent (1%) or greater chance of shallow FLOODING each year usually in the form of a pond, with an average depth between one (1) and three (3) feet and BFES are shown. e. Zone B and Zone X (shaded) are areas that are between the limits of the 100 -YEAR FLOODPLAIN and the 500 -YEAR FLOODPLAIN. f. Zone C and Zone X (unshaded) are areas with a minimal risk of FLOODING. g Zone D is an area with possible but undetermined FLOOD hazards. FLOODPLAIN or FLOOD -PRONE AREA: Any land area susceptible to being inundated as a result of a FLOOD, including the area of land over which floodwater would flow from the spillway of a reservoir. The FEMA-mapped FLOODPLAINS are shown on FEMA's DFIRM, FIRM and FHBM FBFM maps. FLOODPROOF or FLOODPROOFING: Any combination of structural and nonstructural designs, changes or adjustments to STRUCTURES, with the exception of steel rings surrounding oil and gas storage vessels, which reduce or eliminate FLOOD damage to real estate, improved real property, water and sanitary sewer facilities, and STRUCTURES and their contents. FLOODWAY (REGULATORY FLOODWAY): The CHANNEL of a river or other WATERCOURSE and the ADJACENT land areas that must be reserved in order to discharge the BASE FLOOD without cumulatively increasing the WATER SURFACE ELEVATION more than a designated height. The statewide standard for the designated height to be used for all newly studied reaches shall be one-half (%) foot (six [6] inches). Holders of valid LETTERS OF MAP REVISION to existing FLOODWAY delineations may continue to use the FLOODWAY criteria in place at the time of the existing FLOODWAY delineation by FEMA. FEMA's mapped FLOODVVAYS are shown on the FIRM and FHBM FBFM maps. FREEBOARD: The vertical distance in feet above a predicted WATER SURFACE ELEVATION intended to provide a margin of safety to compensate for unknown factors that could contribute to FLOOD heights greater than the height calculated for a selected size FLOOD such as debris blockage of bridge openings and the increased runoff due to urbanization of the watershed. LETTER OF MAP AMENDMENT (LOMA): A letter from FEMA officially revising the effective FIRM and FEMA's acknowledgment that a STRUCTURE and/or property is not located in a SPECIAL FLOOD HAZARD AREA SFHA. MODEL -BACKED APPROXIMATE FLOOD ELEVATION: The 100 -YEAR -FLOOD water surface elevation resulting from a hydraul c model used to determine an Approximate Floodplain. NATIONAL FLOOD INSURANCE PROGRAM (NFIP): FEMA's program of FLOOD insurance coverage and national FLOODPLAIN MANAGEMENT administered in conjunction with the Robert T. Stafford Disaster Relief and Emergency Assistance Act. The NFIP has applicable federal regulations promulgated in CFR Title 44. The U.S. Congress established the NFIP with the passage of the National Flood Insurance Act of 1968. NO -RISE CERTIFICATION: A record of the results of an engineering analysis conducted to determine whether a project will increase FLOOD heights in a FLOODWAY. A NO -RISE CERTIFICATION shall be supported by technical data and signed by a registered Colorado professional engineer. The supporting technical data should be based on the computer program model used to develop the 100 -YEAR FLOODWAY shown on the FIRM or FHBM FBFM. SPECIAL FLOOD HAZARD AREA (SFHA): The land in the 100 -YEAR FLOODPLAIN within the COUNTY subject to a one percent (1%) or greater chance of FLOODING in any given year. The area may be designated as Zone A, A1-30, AE, AH, and AO or Al A99 on the FIRM or FHBM. SPECIAL FLOOD HAZARD AREAS are periodically amended by FEMA via a LETTER OF MAP CHANGE. The designated SPECIAL FLOOD HAZARD ZONE AREAS are as follows: ELEVAT ONS anc FLOOD HAZARD factors have not been determined by FEMA. are between one (1) and three (3} feet and BASE FLOOD ELEVATIONS are shown but no FLOOD HAZARD factors lave been determined by FEMA. c Zone AO is a SPECIAL FLOOD HAZARD AREA where shallow FLOODING occurs and flood no FLOOD HAZARD factors have been determined by FEMA. d. Zones AE and Al -A30 are SPECIAL FLOOD HAZARD AREAS where BASE FLOOD =VA ONS anc _OOD HAZARD -actors have been determined by FEMA. c. Zone B and Zone X (shaded) are SPECIAL FLOOD HAZARD AREAS that are between the limits of the 100 -YEAR and the 500 YEAR FLOODS. f Zone C and Zone X (unshaded) are SPECIAL FLOOD HAZARD AREAS that are at minimal risk of FLOODING. ARTICLE XI Floodplain Management Ordinance Division 1 General Provisions Sec. 23-11-230. Statement of purpose. [A. and B. — No changes] C. It is also the purpose of this ORDINANCE to ensure that the COUNTY'S requirements meet the minimum requirements of the Federal Emergency Management Agency's ('•FEMA") Flood Insurance Program NATIONAL FLOOD INSURANCE PROGRAM (NFIP) Regulations [found at 44 CFR Parts 59, 60, 65 and 70 {2010) and referred to herein to each individual section or collectively as the "Federal Flood Insurance Program Regulations"] and the Colorado Water Conservation Board ("CWCB") "Rules and Regulations for Regulatory Floodplains in Colorado' (referred to herein as "CWCB FLOODPLAIN Rules ), adopted in effect as of January 14, 2011 2022 (found at 2 CCR 408-1). As such, the National FLOOD Insurance Program NFIP regulations and the CWCB FLOODPLAIN Rules are incorporated herein by reference. In the event this ORDINANCE conflicts with federal or state laws and/or regulations, the more restrictive law or regulation will control. Sec. 23-11-250. Basis for establishing SPECIAL FLOOD HAZARD AREA (SFHA). Special Flood Hazard Area The SPECIAL FLOOD HAZARD AREA identified by FEMA in a scientific and engineering report entitled, "The Flood Insurance Study for Weld County, Colorado, and Incorporated Areas," dated January 20, 2016 November 30, 2023, with accompanying Flood Insurance Rate Maps FLOOD INSURANCE RATE MAPs (FIRM) and FHBM FBFM and any revisions thereto, are hereby adopted by reference and declared to be part of this ORDINANCE. These SPECIAL FLOOD HAZARD AREAS identified by the FIS and attendant mapping are the minimum area of applicability of this ORDINANCE and may be supplemented by studies designated and approved by the Board of County Commissioners, CWCB and FEMA. The FLOODPLAIN ADMINISTRATOR shall keep a copy of the AS, FIRMs and/or FHBMs FBFMs on file and available for public inspection. Division 3 Floodplain Development Permit Procedures Sec. 23-11-350. Permit procedures. [A. and B. — No changes] C. Per 44 CFR 60.3(a), FLOODPLAIN DEVELOPMENT PERMIT applications submitted for review shall include, at a minimum, the following information. Applications containing less than the specified requirements shall not be accepted for review unless the applicant has submitted to and had approved by the FLOODPLAIN ADMINISTRATOR written justification as to why a particular requirement does not pertain to the proposed DEVELOPMENT. [1. and 2. - No changes] 3. A map which accurately displays the following information: [a. through d. — No changes] e. WATER SURFACE ELEVATIONS of the BASE FLOOD ELEVATION BFE at the BUILDING site. If the WATER SURFACE ELEVATIONS are not shown on the FBFM or FIRM or FHBM the applicant's engineer shall use acceptable methodology to determine the WATER SURFACE ELEVATIONS and show them on the map; [Remainder of Section — No changes] Division 4 Standards Sec. 23-11-360. General standards. In all SPECIAL FLOOD HAZARD AREAS, the following provisions are required for all DEVELOPMENT, NEW CONSTRUCTION and SUBSTANTIAL IMPROVEMENTS: A. Prior to the START OF CONSTRUCTION or commencement of DEVELOPMENT. a FLOODPLAIN DEVELOPMENT PERMIT shall be obtained. [B. through H. — No changes] I. Per 44 CFR 60.3(a), all new or replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of FLOOD waters into the system and discharge from the system into FLOOD waters. On -site waste d-isposal wastewater treatment systems (OWTS) shall be located to avoid impairment to them or contamination from them during FLOODING. OWTS shall comply with Section 30-8-100 of the Weld County Code Chapter 30 and Colorado Department of Public Health and Environment regulations, no new or expanded individual sewage disposal system can be placed in a FLOODWAY. Per Colorado Department of Public Health and Environment regulations, if a FLOODWAY has not been designated, the FLOODWAY location and elevation shall be engineer. J. Per CWCB FLOODPLAIN Rule 11, a FLOODPLAIN DEVELOPMENT PERMIT shall not be issued for the construction of a new STRUCTURE or ADDITION to an existing STRUCTURE on a property removed from the FLOODPLAIN by the issuance of a FEMA LOMR-F, if the LOWEST FLOOR ELEVATION, including the BASEMENT, is less than one (1) foot (twelve [12] inches) above the BASE FLOOD ELEVATION BFE or MODEL -BACKED APPROXIMATE FLOOD that existed prior to the placement of FILL. ELEVATION K. Per CWCB FLOODPLAIN Rule 12 and 44 CFR 60.3(b), any USE or DEVELOPMENT which causes or results in an ALTERATION OR RELOCATION OF A WATERCOURSE shall comply with the requirements listed below. The applicant shall provide evidence that: [1. and 2. — No changes] 3. Any ALTERATION OR RELOCATION OF A WATERCOURSE shall be designed and sealed by a registered Colorado professional engineer or certified profess-ional hydrologist. [4. Through 10. — No changes] [L. — No change] M Barns with no habitable living spaces or sanitary systems, toilets, loafing sheds, detached garages with no habitable living spaces, boathouses/boat docks with no habitable living spaces and storage sheds may be FLOODPROOFED by the FLOOD-VENTINGventing measures described below: 1. FLOOD-VENTEDvented STRUCTURES shall be anchored to resist flotation, collapse and lateral movement; 2. FLOOD-VENTEDvented STRUCTURES shall be constructed using FLOOD -resistant materials below the BASE FLOOD ELEVATION, plus one (1) foot: 3. All utility equipment in a FLOOD-VENTEDvented STRUCTURE shall be elevated or made WATERTIGHT to prevent the accumulation of FLOOD water in the components; [Remainder of subsection — No changes] N. All OIL AND GAS PRODUCTION FACILITIES including TANK BATTERIES, shall be anchored to resist flotation, collapse or lateral movement. OIL AND GAS PRODUCTION FACILITIES and OIL AND GAS STORAGE FACILITIES shall be ELEVATED, FLOODPROOFED or FLOOD-VENTEDvented, as appropriate. and OIL AND GAS STORAGE FACILITIES [Remainder of Section — No changes] Sec. 23-11-370. Specific standards for Approximate Floodplains (Zone A). In addition to the general standards in Section 23-11-360 above, the following provisions are required for all DEVELOPMENT, NEW CONSTRUCTION and SUBSTANTIAL IMPROVEMENTS that are located in SPECIAL FLOOD HAZARD AREAS designated as Zone A (Approximate Floodplain): [Remainder of Section — No changes] Sec. 23-11-380. Specific standards for Floodplains FLOODPLAINS with Base Flood Elevations BASE FLOOD ELEVATIONS or determined depths (Zones A1 -A30, AE, AH, and AO and AE). In addition to the general standards in Section 23-11-360 above and specific standards for Approximate Floodplains in Section 23-11-370 above, the following provisions are required for all NEW CONSTRUCTION AND SUBSTANTIAL IMPROVEMENTS that are located in SPECIAL FLOOD HAZARD AREAS designated as Zones A1 -A30, AH, and AO and AE: DEVELOPMENT, [Remainder of Section — No changes] Sec. 23-11-390. Specific standards for Floodplains AE, FLOODPLAINS with Floodways FLOODWAYS. FLOODWAYS are administrative limits and tools used to regulate existing and future FLOODPLAIN DEVELOPMENT. The State has adopted FLOODWAY standards that are more stringent than the FEMA minimum standard. Located within the SPECIAL FLOOD HAZARD AREA are areas designated as FLOODWAY. Since the FLOODWAY is extremely hazardous due to the velocity of FLOOD waters which carry debris, potential projectiles and erosion potential, the following provisions, in addition to the provisions of the general standards in Section 23-11-360, specific standards for Approximate Floodplains in Section 23-11-370 and specific standards for FLOODPLAINS with BASE FLOOD ELEVATIONS in Section 23-11- 380, for all DEVELOPMENT, NEW CONSTRUCTION and SUBSTANTIAL IMPROVEMENTS that are located in FLOODWAYS shall apply: A. Per 44 CFR 60.3(d), encroachments within the REGULATORY FLOODWAY are prohibited, including FILL, NEW CONSTRUCTION, SUBSTANTIAL IMPROVEMENTS and other DEVELOPMENT, unless it has been demonstrated through hydrologic and hydraulic analyses performed by a licensed registered Colorado professional engineer and in accordance with standard engineering practices that the proposed encroachment would not result in any increase, as shown by a NO -RISE CERTIFICATION, in FLOOD levels within the COUNTY during the occurrence of the BASE FLOOD discharge. Per CWCB FLOODPLAIN Rule 7, FEMA Risk Mapping Assessment and Planning (Risk MAP) Technical References, Guidelines and Standards for Flood Risk Analysis and Mapping Activities, and associated resource documents any other FEMA accepted methodology are considered to be standard engineering practices standards for delineation of regulatory FLOODPLAIN information. [Remainder of Section — No changes] Sec. 23-11-400. Specific standards for Floodplain FLOODPLAIN studies. CWCB FLOODPLAIN Rules 7, 9 and 10 provide specific standards for conducting FLOODPLAIN studies. [A. through B. — No changes] C. Per CWCB FLOODPLAIN Rule 10.. the use of LEVEES for property protection, FLOOD control and FLOOD hazard mitigation is not encouraged unless other mitigation alternatives are not viable. [1. through 5. — No changes] 6. An operation and maintenance manual that ensures continuing proper function of the LEVEE shall be prepared and updated. The LEVEE shall be structurally sound and adequately maintained. Sedimentation effects shall be considered for all LEVEE projects. Certification from a federal or state agency or a Colorado registered professional engineer that the LEVEE meets the minimum FREEBOARD freeboard criteria stated above and that it appears, on visual inspection, to be structurally sound and adequately maintained shall be required on a three-year basis and provided to the CWCB. LEVEES that have obvious structural defects or that are obviously lacking in proper maintenance shall not be considered in the hydraulic analysis. [7. — No change] 8. A minimum LEVEE FREEBOARD freeboard of three (3) feet shall be necessary with an additional one (1) foot of FREEBOARD freeboard within one hundred (100) feet of either side of hydraulic structures within the LEVEE or wherever the flow is constricted, such as at bridges. An additional one-half (0.5) foot above this minimum is also required at the upstream end of the LEVEE. [9. — No change] 10. Evaluation of LEVEES shall not consider human intervention (e.g., capping of LEVEES by sandbagging, earth fill or flashboards) for the purpose of increasing a LEVEE'S design level of protection during an imminent FLOOD. Human intervention shall only be considered for the operation of closure structures (e.g., gates or stop logs) in a LEVEE SYSTEM designed to provide at least the level of BASE FLOOD protection, including adequate FREEBOARD freeboard as described above, provided that such human operation is specifically included in an emergency response plan adopted by the COUNTY. [11. — No change] Summary of the Weld County Planning Commission Meeting Tuesday, September 5, 2023 A regular meeting of the Weld County Planning Commission was held in the Weld County Administration Building, Hearing Room, 1150 O Street, Greeley, Colorado This meeting was called to order by Chair, Elijah Hatch, at 1 30 pm Roll Call Present Elijah Hatch, Skip Holland, Michael Wailes, Pamela Edens, Michael Palizzi, Shana Morgan, Virginia Guderjahn, Barney Hammond Absent Butch White Also Present Kim Ogle, Diana Aungst, and Tom Parko, Department of Planning Services, Lauren Light, Department of Health, Karin McDougal, County Attorney, and Kris Ranslem, Secretary Case Number Presented by Request Ordinance 2023-12 Tom Parko/Diana Aungst In the Matter of Repealing and Reenacting, with Amendments, Chapter 23 Zoning of the Weld County Code (Floodplain Regulations) Tom Parko, Planning Services, presented Ordinance 2023-12 Diana Aungst, Planning Services provided a brief summary of the proposed code changes relating to floodplain regulations Commissioner Holland asked if someone from the county has asked what impacts this has on future planning Mr Parko said that staff has looked at all the FIRM panels but didn't look at it from an engineering aspect He added that this would be a very costly endeavor for the county to do that because we would have to hire someone to refute FEMA on that Mr Parko said that there were several public meetings that they could walk the landowners through challenging it if they believe they were in the floodplain or not He added that Weld County does allow landowners to build in the floodplain or floodway with additional requirements, whereas there are several counties that do not The Chair asked if there was anyone in the audience who wished to speak for or against this Ordinance No one wished to speak Motion Forward Ordinance 2023-12 to the Board of County Commissioners along with the Planning Commission's recommendation of approval, Moved by Skip Holland, Seconded by Pamela Edens Motion carried unanimously Meeting adjourned at 4 47 pm Respectfully submitted, Kristine Ranslem Secretary 1 Hello