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HomeMy WebLinkAbout2.0 BOCC Staff Report 12.17.2001o BOCC 12/17/01 PROJECT INFORMATION AND STAFF COMMENTS REQUEST: Review of a floodplain special use permit in Rifle Village South Subdivision APPLICANT: Brian & Taani Rust LOCATION: Parcel B, Rifle Village South Filing no. 1 ENGINEER: Colorado River Engineering I. Description of the Proposal and Background Information: The project site is about 8 1/2 acres in size and is located within the Rifle Village South 1 Subdivision/ This portion of the county is located within a delineated floodplain area and requires a floodplain special use permit. The property is gently sloped in a northwesterly direction without any defined drainage channels or watercourses. Village Drive provides access on the southern property boundary. The lot is;currentlY in an -un -improved State and is predominately covered by sagebrush. Planned improvementsincludea driveway,: single family residence, anda future .batn/garage/shofl ' The January 3, 1986 Flood Insurance Study of Unincorporated Garfield County, produced by FEMA identifies the site as Lying in Zone AO of the floodplain. The AO floodplain is an alluviat floodplain fan with a shallow (1 foot) flooding depth? The source of thefloodwater is d Helmer: Gulch! Alluvial fans do not have distinct watercourses and the path of flooding is unpredictable. The floodplain mapping conservatively assumes blanket coverage over the entire alluvial fan including Rifle Village South Subdivision. The existing ground elevatiorf at the proposed home location was surveyed at an elevation of 5,344.6''. The flood elevation is one foot above the ground elevation. The finished floor elevation must be constructed at 5,346.6 feet in order to be one foot above the floodplain elevation (no basement areto be constructed). II. Zoning R9ons a ?d'sta f Comments: Section 6.08 df the Zoning Resolution describes the administrative procedures to obtain a floodplain special use permit. Any floodplain special use permit application must fulfill the following criteria: (1) To assure that all necessary permits have been received from those governmental agencies from which approval is required by Federal or State Law, including Section 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.0 1344. 1 (2) To determine whether proposed building sites will be reasonably safe from flooding, and that the structure will be in compliance with the applicable provisions for uses and standards for construction set forth in this Resolution. (3) To determine if the proposed development is located in the floodway. If located in the floodway, assure that encroachment provisions of Section 6.09.01(1)(A) are met. (4) To assure that adjacent communities, the Colorado Water Conservation Board and Federal Emergency Management Agency have been notified of the proposed watercourse alteration or relocation. (5) To assure that the carrying capacity of the altered/relocated watercourse is maintained. (A. 85-211) The application addresses and fulfills all these criteria. A signed and stamped statement has been provided from a licensed engineer which states that all construction will be safe from flooding and that no additional permits are required from state or governmental agencies. The project is not located within a floodway and does not propose altering a watercourse, nor will it alter the capacity of the watercourse. Section 6.09.02 specifically addresses Flood Fringe/Flood Prone Areas: (1) Prohibited Uses and Activities. The following uses and activities are prohibited in the Flood Fringe/Flood Prone Areas: (A) The development, use, fill, construction, substantial improvement or alteration on or above any portion of the Flood Fringe or Flood Prone Areas which alone, or cumulatively with other activities, would cause or result in the danger of substantial solid debris being carried downstream by floodwaters. This project will not cause substantial debris being carried downstream by floodwaters. (B) The storage or processing of materials that in times of flooding are buoyant, flammable, explosive or otherwise potentially injurious to human, animal or plant life. This project will not result in the storage or processing of materials that would be injurious to humans in times of flooding. (C) The disposal of garbage or other solid waste materials. This project will not result in the disposal of garbage or other solid waste material. (D) Any obstruction which would adversely affect the efficiency of or restrict the flow capacity of a designated floodplain so as to cause foreseeable damage to others. This project will not cause an obstruction which would adversely affect the efficiency or restrict the flow capacity of a designated floodplain. (2) Permissible Uses. All Special Uses permitted in the Floodway, and all lawful uses permitted 2 by the underlying zoning, subject to Section 6.09.02(1) of this Regulation and the regulations concerning the Special Use Permit, are permitted in the Flood Fringe and Flood Prone Areas. A single family residence is a permissable use in the A/R/RD zone district. The building described as the barn/garage/shop is also a permissable use. Building permits will need to be obtained for both structures. A access permit must be obtained from the Road. and Bridge department prior to installation of the driveway 4fity, (3) Performance Standards. The following performance standards must be met for development in the Flood Fringe or Flood Prone Areas: (A) The lowest floor, including basement, of any new or substantially improved building designed for residential occupancy shall not be less than one (1) foot above the maximum water elevation of the 100 Year Flood All proposed building improvements have elevations one foot above the 100 year floodplain elevation. (B) All new construction or substantial improvements shall be reasonably safe from flooding. All proposed improvements will be reasonably safe from flooding. (C) Any new construction or substantial improvement designed for commercial or industrial uses shall either: (i)Elevate the lowest floor level, including basement, to not less than one (1) foot above the maximum water surface elevation of the 100 Year Flood; or (ii)Provide flood proofing improvements so that below an elevation of one (1) foot above the maximum water elevation of the 100 Year Flood, the structure, together with attendant utility and sanitary facilities, is water tight with walls substantially impermeable to the passage of water. Structural components shall be capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. Evidence shall be submitted and certified by a registered professional engineer or architect that the flood proofing meet the standards as set forth herein. This criteria is not applicable as no commercial or industrial uses are being proposed (D) Any proposed development shall be reviewed by the Floodplain Administrator to insure that the potential for flood damage by the 100 Year Flood is minimized, that all public utilities and facilities are located, designed and constructed so as to minimize damage by the 100 Year Flood and that adequate drainage is provided to reduce exposure to flood hazards. The potential for flood damage by the 100 Year Flood has been minimized by elevating the finished floor elevation of all structures to one foot above the 100 year floodplain. (E) All new construction or substantial improvements shall be designed and adequately anchored to prevent flotation, collapse or lateral movement, be constructed with materials 3 and utility equipment resistant to flood damage, and be constructed by methods that minimize flood damage. The application states that this criteria is not applicable since standard building code addresses these issues. All proposed construction shall be adequately anchored, whether addressed by building code or not. (F) New or replacement water supply systems and sanitary sewage systems shall be designed so as to minimize or eliminate infiltration of floodwaters. On-site individual sewage disposal systems shall be located so as to avoid impairment of them or contamination from them during a 100 Year Flood. The City of Rifle supplies water and wastewater services to the property. No new systems will be installed as part of this application. (G) Within any area subject to sheet flow (Zone "AO" on the Flood Insurance Rate Maps) all new construction and substantial improvements of residential structures shall have the lowest floor, including basement, elevated above the highest adjacent grade of the nearest street to or above the depth number specified on the Flood Maps. Any new construction or substantial improvements of nonresidential structures in areas identified as subject to sheet flow shall have the lowest floor, including basement, elevated above the highest adjacent grade to or above the depth number specified on the Flood Maps, or, together with attendant utility and sanitary facilities, be completely flood proofed to or above the elevation of the water surface as specified on the Flood Maps. The application states, "The depth on the flood maps is one (1) foot. It is our opinion that the finished floor of the home could be safely protected from flooding if constructed 1 -foot above the existing ground elevation as allowed by this section of code. However, this section of the code is in conflict with the above performance standard (A) that requires 2 -feet above the existing ground for this application. Our hydrological assessment of intent of this standard (G) is for sheet flow flood areas where Standard (A) is not applicable. Unfortunately, the language in the county code does not discuss the difference between these standards. This section of the county code is therefore no applicable since Standard (A) will always be more restrictive". (H) Require that all manufactured homes or those to be substantially improved to be placed within Zone A on a community's FEMA or FIRM shall be installed using methods and practices which minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse or lateral movement. Methods of anchoring may include, but are not limited to, use of over -the -top or frame ties to ground anchors. This requirement is in addition to applicable State and local anchoring requirements for resisting wind forces. A manufactured home should be elevated a minimum of one (1) foot above the base flood level and anchored to the elevated foundation. (A. 85-211; 89-057; 91-088) This section is not applicable as the property not located within Zone A. Staff finds that the application appears to completely and adequately address the above zoning 4 regulations. III. Recommended Findings: 1. That proper public notice was provided as required for the hearing before the Board of County Commissioners. 2, That the hearing before the Board of County Commissioners was extensive and complete, that all pertinent facts, matters and issues were submitted and that all interested parties were heard at that meeting. 3. That the application is in conformance with the Garfield County Zoning Resolution of 1978, as amended. 4. That for the above stated and other reasons, the proposed floodplain special use permit is in the best interest of the health, safety, morals, convenience, order, prosperity and welfare of the citizens of Garfield County. IV. Recommendation: Staff recommends the Board of County Commissioners appr.,ovetbe Rust floodplain special use permit application concerning proposed improvements with the following conditions: 1. That all representations of the applicant, either within the application or stated at the hearing before the Board of County Commissioners, shall be considered conditions of approval; 2. That the Garfield County Zoning Resolution of 1978, as amended, and any other applicable state or federal laws concerning the 100 yr. floodplain, be complied with; 3. That all State and Local health standards be complied with; 4. That a flood elevation certificate, signed and stamped by a licensed engineer or surveyor (in the state of Colorado), be submitted to the Garfield County Planning Department prior to issuance of a Certificate of Occupancy; 5. That all building improvements be installed consistent with the Garfield County Building Code and that the lowest floor elevation shall not be lower than 5,346.6 feet. (4t / '5 7- /"T l � M Gc—,-L(Yy�� u.s 5