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HomeMy WebLinkAbout2.0 BOCC Staff Report 09.06.2005BOCC 9-6-2005 RW PROJECT INFORMATION AND STAFF COMMENTS REQUEST Special Use Permit for work in the Floodplain — Bank Stabilization APPLICANT / OWNER Mark Gould LOCATION 0200 Oak Lane — Westbank Ranch Subdivision SITE DATA 2.25 Acres PARCEL ID NUMBER 2185-353-01-033 EXISTING ZONING RLSD — Residential Limited Suburban Density 1. SITE LOCATION AND DESCRPTION: Located in the Westbank Ranch Subdivision, South of Glenwood Springs access is from CR 109, Lot 21 of the subject subdivision. 2. DEVELOPMENT PROPOSAL: The applicant is proposing to construct adjudicated outlet features with bank stabilization. The work will involve construction of two stream channels that will route tailwater diverted from the Robertson Ditch. The diverted water from the historic return flow channel that flows through the subject property near the upstream property line will be put to use as water features on the site. The existing ditch water that currently flows into the river will be split and routed through the property in pipelines and lined open channel streams. The outfall locations of these streams at the river embankment will be above the mean high water line and constructed with select soil replacement matter and embedded rip rap. The site plan reflects only a very small portion of the outfall locations will be in the floodplain. All other proposed improvements will not be in the floodplain or the floodway. 3. APPLICABILITY: Any use to be developed in the floodplain shall be required to obtain a Special Use Permit, in accordance with the applicable regulations of Section 9 of this Zoning Resolution concerning the submission and processing of such permits. In addition to the determinations to be made by the Building Official under the provisions of said 1 Section 9, all applications for the Special Use Permit under this Regulation shall be reviewed by the Floodplain Administrator. 4. REVIEW AGENCY AND OTHER COMMENTS: This item has been referred to the US Army Corp of Engineers. Resource Engineering, outside review agency for Staff, has also reviewed the application. Below are the respective agency and outside review comments: US Army Corp of Engineers: No comments received. Resource Engineering: A 404 permit will not be required. Please see Exhibit H. 5. REVIEW CRITERIA §6.08.01 Special Use Permit Required (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.C. 1344. STAFF COMMENT: The applicant has stated that all proposed work will occur above the mean high water (MHW) line without any encroachment or disturbance below the MHW. There will be no placement of additional fill in the floodplain. All work conducted above the MHW requires no Federal or State Permits. Staff would conclude the applicant has submitted the proper material showing that no further permits will be required by Federal or State Agencies. (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. STAFF COMMENT: There are no structures proposed in the floodplain. The only work that will take place in the floodplain will be bank stabilization. (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. STAFF COMMENT: The applicant has submitted copies of the FEMA map showing that no structure, building, bank stabilization or work is proposed in the floodway. (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. 2 STAFF COMMENT: A copy of the application to the District Court Water Division 38 has been submitted, showing the applicant is applying for the tail water adjudication and esthetic feature of the Robertson Ditch. (5)To assure that the carrying capacity of the altered/relocated watercourse is maintained. (A. 85-211) .09 STAFF COMMENT: The proposed bank stabilization will not increase the carrying capacity of the Roaring Fork River, or affect the capacity of the Robertson Tailwater Ditch. 6. SPECIAL USES AND STANDARDS FOR CONSTRUCTION §6.09.02 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. STAFF COMMENT: The purpose of this application is to improve the discharge features of the river bank. By improving and stabilizing the bank, the amount of solid debris carried downstream will decrease. (B) The storage or processing of materials that in times of flooding is buoyant, flammable, explosive or otherwise potentially injurious to human, animal or plant life. STAFF COMMENT: There will be no storing or processing of materials in the floodplain. (C) The disposal of garbage or other solid waste materials. STAFF COMMENT: There will be no storage of garbage or solid waste. (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. STAFF COMMENT: The intent and purpose of this application is to mitigate any future problems in the floodplain outlet area. 3 (2) Permissible Uses. All Special Uses permitted in the Floodway, and all lawful uses permitted 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. STAFF COMMENT: The applicant has submitted plans showing the FEMA Floodway and the location of the proposed construction. No construction or work will be in the Floodway. (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. STAFF COMMENT: There are no residential structures proposed. (B) All new construction or substantial improvements shall be reasonably safe from flooding. STAFF COMMENT: The proposed bank stabilization is above the MHW mark and should 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 meets the standards as set forth herein. 4 STAFF COMMENT: No industrial or commercial uses are 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. STAFF COMMENT: It is assumed this standard is for habitable areas. The proposal is for rip rap bank stabilization that should mitigate some flood hazards. (E) All new construction or substantial improvements shall be designed and adequately anchored to prevent flotation, collapse or lateral movement, be constructed with materials and utility equipment resistant to flood damage, and be constructed by methods that minimize flood damage. STAFF COMMENT: The bank stabilization will increase the outlet feature's ability to resist flood damage. (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. STAFF COMMENT: No water supply or sewage systems are proposed. (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. STAFF COMMENT: No residential structures are proposed. (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 5 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) STAFF COMMENT: No manufactured homes are proposed. 7. SUGGESTED 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 for the above stated and other reasons, the proposed Special Use Permit is in the best interest of the health, safety, morals, convenience, order, prosperity and welfare of the citizens of Garfield County. 4. That the Special Use Permit application is in conformance to the Garfield County Zoning Resolution of 1978, as amended. 8. RECOMMENDATION Staff recommends APPROVAL with the following conditions: 1. 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 unless otherwise modified by the Board. 2. The Applicant shall meet all requirements of the Garfield County Zoning Resolution of 1978, as amended. 9. RECOMMENDED MOTION "I move to approve the Special Use Permit request for construction of two outlet features for bank stabilization in the Floodplain at 200 Oak Lane, Lot 21 of the Westbank Ranch Subdivision, Glenwood Springs, Colorado with the conditions proposed by Staff." 6 .....'RESOURCE . l.•.. ■ ■■.■ E N G I N E E R I N G I N C. Richard Wheeler ,` CIF] V 1 August 30, 2005 Garfield County Building and Planning dept 108 8th Street, Suite 201 AUG 3 0 2005 . Glenwood Springs CO 81601 GARFIELD COUNTY RE: Gould Floodplain Special Use Permit ReviewsUILDINC & PLANNING Dear Richard: At the request of Garfield County, Resource Engineering, Inc. (RESOURCE) has reviewed the Gould Floodplain Special Use Permit Application. The application submittal was prepared by Sopris Engineering, LLC and is dated May 2, 2005. Our comments are presented below. PROJECT SUMMARY The proposed project subject to the floodplain special use permit involves construction of water feature channels within the 100 year floodplain and the floodway. The channels will be excavated and partially backfilled with bedding material, a liner, and rock rip rap. The final grade will be below the existing grade. ANALYSIS SUMMARY The proposed activity is consistent with the allowed uses and activities and meets the standards for construction as outlined in Section 6.09 of the Garfield County floodplain regulations. Specifically, it is consistent with the applicable floodway encroachment provisions of Section 6.09.01(1)(A) and the floodplain hazard provisions of Section 6.09..02 (1)(A). In addition, we concur with the Sopris Engineering opinion that Section 404 permitting is not applicable since the project is not located on tributary water of the U.S., is not within wetland area, and is above the ordinary high water line of the Roaring Fork River (refer to Section 6.08.01(1 ))• Please call if you have any questions or need additional information. Sincerely, RESOURCE ING, INC. Michael J. Erb, , P.E. Water Reso fe Engineer MJ E/mmm 885-38.0 E:\Client1885\rwheeler gould flood plain 885.doc CC: Yancy Nichol, P.E., Sopris Engineering EXHIBIT Consulting Engineers and Hydrologists 909 Colorado Avenue • Glenwood Springs, CO 81 601 • (970) 945-6777 • Fax (970) 945-11 37