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HomeMy WebLinkAbout2.0 Staff Report & Attachments 08.16.2016Director Decision 8/16/16 FDPA-04-16-8445 GH PROJECT INFORMATION AND STAFF COMMENTS TYPE OF REVIEW Administrative Review for a Flood Plain Development Permit APPLICANT (OWNER) CMH Homes Inc. REPRESENTATIVE Shawn Ruse and Steve Snyder, CMH Homes Inc. LOCATION PROPERTY SIZE ZONING Lots 8 and 9, Block 3, Rifle Village South First Filing, according to the Plat thereof, recorded on October 8, 1964, in Reception No. 227220 at the Office of the Clerk and Recorder, County of Garfield, State of Colorado. The property is located approximately 4 miles west of the Rifle City Limits by way of County Road 320, off of Remington Street. The property is also known by Assessor's Parcel No. 2217-202-05-053. 0.277 acres Residential Urban (RU) I. DESCRIPTION OF THE PROPOSAL The Applicant is requesting approval for a Flood Plain Development Permit to allow placement of a single family manufactured home on the property within the 100 year flood plain. The unit will be placed on a new lot that will combine Lots 8 and 9 into one lot. The Applicant has applied for an amended plat to merge the lots and has received a Director's Decision conditionally approving the proposed plat amendment. The site is currently a vacant residential lot, with generally level grades/topography, and surrounded by other residential lots and homes. The Applicant has proposed to place the unit on a permanent foundation, elevating it one foot above the 100 year flood plain, and anchoring the unit to the foundation. It will be centrally located on the new lot in compliance with all setback provisions. The Application includes general grading plans to address drainage issues around the proposed unit. 1 The Application includes a detailed engineering plan for the proposal along with responses to code sections on flood plain development standards and flood plain analysis. City of Rifle J VICINITY MAP i11,100 •a lir Subject j Parcel II. AUTHORITY A. The Land Use and Development Code Section 3-301 contains regulations and standards specific to development within a 100 year flood plain. Section 4-109 contains provisions related to the review process (Administrative) and the review criteria for development within a 100 year flood plain and permitting requirements. B. Section 4-203(0) contains a description of the requirements associated with a Floodplain Analysis. Table 4-201 contains submittal requirements for Development in a 100 Year Flood Plain. C. The Application is also subject to compliance with all zoning provisions including stream setback provisions contained in Article 7 of the Land Use and Development Code. III. STAFF ANALYSIS Referral — Public Comments 1. The Applicant has provided evidence of proper mailing of public notice for the Director's Decision in compliance with the Land Use and Development Code provisions. No public comments on the request have been received. Referral Comments received from various agencies and are attached and summarized as follows: 2. County Consulting Engineer, Michael Erion, Resource Engineering: • Review comments indicated Resource Engineering general concurs with the responses to the applicable code sections contained in the Applicant's engineering report prepared by CIVCO Engineering subject to conditions related to clarifying the anchoring system, grading and drainage details, compliance with crawl space opening requirements, and edits to the Elevation Certificate. The Resource referral letter is attached. 3. Army Corp of Engineers, City of Rifle, Garfield County Environmental Health, and Colorado River Fire Rescue: No comments were received. 1C',C SITE PLAN EXCE RPT I 11 III. STAFF ANALYSIS Section 4-109 (C) Review Criteria: The following comments address the review criteria contained in Section 4-109 (C) (1 — 10). Staff analyses are shown in bold. 1. The danger to life and property due to flooding or erosion damage; The Applicant proposes to install the unit in compliance with the County and FEMA requirements including elevation and anchoring. The site will be properly graded. A condition of approval is appropriate to address elevation certification and crawl space openings pursuant to FEMA requirements. Revegetation of the graded yard areas should also be required to minimize the potential for soil erosion. These requirements are intended to reduce the danger to life and property due to flooding and erosion damage. 2. The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner; Compliance with the Code and FEMA requirements noted above are intended to reduce the potential for damage due to flooding. The shallow flooding depth and velocities also help to reduce the potential for damage. The site is located in a Zone AO with a flood depth of 1 ft. and velocity of 4 fps(feet per second). EXCERPT OF FLOOD PLAIN MAPPING FROM THE SUBMITTALS Appmxjrrote project loca:.cr 19 ZONE ATIOMAE flI10 INSURANCE PROGRAM FIRM FLOOD INSURANCE RATE MAP GARFI[ LU COLA 11 COLORADO IAINIIN((l MP< IR STF1) MA 'Si PANEL 1353 OF 1900 r' COMMUNITYPANELNOMNEA 000205 1353 0 MAP REVISED: JANUARY 3, 1986 3. The danger that materials may be swept onto other lands to the injury of others; Anchoring the unit to the permanent foundation, compliance with crawl space openings, and landscaping/re-vegetation will reduce the potential of materials being swept off-site. 4. The compatibility of the proposed use with existing and anticipated development; The unit is proposed to be located within an existing residential subdivision, Rifle Village South. No additional development is anticipated on the site. 5. The safety of access to the property in times of flood for ordinary and emergency vehicles; Access to the property is by existing roadways. Based on the existing FEMA mapping depth of flood waters is modelled to be approximately 1 ft. deep. No formal comments from the Colorado River Fire and Rescue District were received. 6. The costs of providing governmental services during and after flood conditions, including maintenance and repair of streets and bridges, and public utilities and facilities such as sewer, gas, electrical, and water systems; The proposed unit will be served with central water and sewer services from the City of Rifle. Utility connections should be protected from infiltration by flood waters. Elevation of utility facilities and equipment (such as air conditioning units or swamp coolers) should be required. No additional impacts on governmental services are anticipated based on the proposed use. 7. The expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters and the effects of wave action, if applicable, expected at the site; The technical evaluations prepared by the Applicant's Engineer address characteristics of the shallow flooding anticipated on the site including anticipated depth and velocity. The shallow depth and slower velocities should limit impacts. 8. The necessity to the facility of a waterfront location, where applicable; The property is located in an existing residential subdivision and does not have a water front location. 9. The availability of alternative locations, not subject to flooding or erosion damage, for the proposed use; and The size of the property and location within an existing residential subdivision limit alternative locations. 10. The relationship of the proposed use to the Comprehensive Plan for that area. The Applicant's proposal is generally consistent with the Comprehensive Plan Future Land Use Designation of the existing residential subdivision within the Rifle Urban Growth area and with a flood plain overlay. The Application was referred to the City of Rifle with no comments received. The Application including the engineering and compliance with elevation and anchoring requirements is generally consistent with the Comprehensive Plan designations including the Section on Natural Resource Protection. Excerpts from the Garfield County Comprehensive Plan that address flood plain issues are noted below: Section 8 Natural Resources Goal #2: Preserve natural drainage patterns so the cumulative impact of public and private land use activities will not cause storm drainage and floodwater patterns to exceed the capacity of natural or constructed drainage ways, or to subject other areas to an increased potential for damage due to flooding, erosion or sedimentation or result in pollution to streams, rivers or other natural bodies of water. Section 8 Natural Resources Policies #2: Garfield County will encourage the protection of watersheds, flood plains, and riparian areas. IV. SUPPLEMENTAL ANALYSIS — ENGINEERING & DESIGN 1. Section 3-301 (B)(5) requires installation of manufactured homes to use methods and practices that minimize flood damage. The section specifically requires elevation and anchoring to resist floatation, collapse, or lateral movement. The Application addresses these standards as follows: a. Elevation of the lowest finished floor to one foot above the anticipated depth of food waters pursuant to the FEMA Flood Plain mapping. b. Anchoring the unit using over the top frame ties anchored to the permanent foundation. EXCERPT FROM ENGINEERING PLANS 41,11,047n Miggrrr o g 4 2. Section 3-301 (B)(6) & (7) require that all water supply systems and sanitary sewage systems be designed to minimize or eliminate infiltration of flood waters. The Applicant will be utilizing connection to City of Rifle water and sanitary sewer systems and has represented that all connections will be water tight or elevated above the depth of flood waters. 3. Section 3-301(C)(1) requires elevation of residential structures and provision of an elevation certificate completed by professional engineer, architect, or land surveyor. The Applicant has provided a preliminary certificate and will need to provide a final certificate once construction is completed. 4. Section 3-301 (C)(4) requires compliance with specific standards for placement of Manufactured Homes including anchoring, permanent foundations, and elevation. The Applicants submittals reflect compliance with these requirements. 5. Section 3-301 (E) requires that adequate drainage paths around structures be provided to guide flood waters around and away from proposed structures and that drainage shall not adversely impact adjacent properties. The Applicant's Engineer includes in his analysis information on grading around the proposed home, representations that there will be positive grading away from the structure, and that the historic pattern of drainage will be maintained. The Engineer's report should be supplemented with a determination that the proposed grading plan will not adversely affect any adjacent property owners. 6. The referral comments from Michael Erion with Resource Engineering include specific recommendations that will be addressed as conditions of approval. They include: a. The anchoring system is listed an over the top tie down in the CIVCO report, but the design drawings show a foundation system with tie straps to the floor joists. Both systems are acceptable, but the Applicant should clarify the design so that the flood plain permit and building permit are consistent for the project. b. The grading plan on sheet 2 of the CIVCO drawings calls out a high point on the west fence line with half the drainage flowing north and half flowing to the south. The existing topography does not appear to support this label. Resource agrees with the approach so as to not impact the property to the west. It is recommended that the drawing indicate specific elevations at the high point and at the northwest and southwest corners for the contractor to provide the intended drainage concept. c. The plans indicate a crawl space for the foundation system. The Applicant should address location, elevation and size of the openings and address compliance with enclosure opening if appropriate. Specifically, the east side of the structure foundation could be subject to flooding in the crawl space. d. The as -built Elevation Certificate should indicate one foot base flood depth rather than an elevation in Box 9. V. SUGGESTED FINDINGS The following suggested findings support an approval of the requested Flood Plain Development Permit 1. That proper public notice was provided as required for the Director's Decision. 2. Consideration of the Application was extensive and complete, that all pertinent facts, matters and issues were submitted and that all interested parties were given the opportunity to provide input prior to the Director's Decision. 3. That for the above stated and other reasons the proposed CMH Homes Inc. Flood Plain Development Permit is in the best interest of the health, safety, convenience, order, prosperity and welfare of the citizens of Garfield County. 4. That with the adoption of conditions, the application is in general conformance with the 2030 Comprehensive Plan, as amended. 5. That with the adoptions of conditions the application has adequately met the requirements of the Garfield County Land Use and Development Code, as amended. VI. RECOMMENDATION Staff supports a Director Decision approving the CMH Home Inc. Application for a Flood Plain Development Permit for an the installation of a manufactured home on Lots 8 & 9, Block 3, Rifle Village South, based on the above suggested findings and subject to the following conditions: 1. That the Applicant comply with all Federal Emergency Management Agency (FEMA) requirements and requirements of the Garfield County Land Use and Development Code applicable to the proposed residential development. 2. That all representations contained in the Application and in the Engineering Report completed by CIVCO Engineering Inc., dated May 4, 2016 shall be considered conditions of approval. Said representations include but are not limited to technical flood plain evaluations, plans for elevation of the structure, grading information, foundation plans, and plans for anchoring the structure. A copy of the Flood Plain Permit and the Engineering Report shall be required to be submitted with the Building Permit Application. 3. Prior to the issuance of the Flood Plain Development Permit the Applicant shall demonstrate compliance with the referral comments from the County's Consulting Engineer, Michael Erion with Resource Engineering as outlined below: a. The anchoring system is listed an over the top tie down in the CIVCO report, but the design drawings show a foundation system with tie straps to the floor joists. Both systems are acceptable, but the Applicant should clarify the design so that the flood plain permit and building permit are consistent for the project. b. The grading plan on sheet 2 of the CIVCO drawings calls out a high point on the west fence line with half the drainage flowing north and half flowing to the south. The existing topography does not appear to support this label. Resource agrees with the approach so as to not impact the property to the west. It is recommended that the drawing indicate specific elevations at the high point and at the northwest and southwest corners for the contractor to provide the intended drainage concept. c. The plans indicate a crawl space for the foundation system. The Applicant should address location, elevation and size of the openings and address compliance with enclosure opening if appropriate. Specifically, the east side of the structure foundation could be subject to flooding in the crawl space. d. The as -built Elevation Certificate should indicate one foot base flood depth rather than an elevation in Box 9. 4. Prior to the issuance of the Flood Plain Development Permit the Applicant shall provide an update or supplement to the Flood Plain Report which shall address the following: a. Confirmation that all utility connections are designed and protected from infiltration by flood waters and confirmation that all utility facilities and equipment such as air conditioning units will be elevated at least one foot above the FEMA anticipated level of flood waters. This information shall be provided with the building permit application. b. Plans for landscaping or re -vegetation of disturbed areas to minimize the potential for soil erosion in the event of a flood. Evidence of initial re -seeding shall be required prior to issuance of a certificate of occupancy. c. A determination that the proposed grading plan will not adversely affect any adjacent property owners. d. Specific plans for crawl space openings including size and location demonstrating compliance with FEMA requirements. 5. The Applicant shall survey the elevation of the foundation prior to construction to ensure the correct elevation for the finished floor will be achieved. The Applicant shall provide a completed Elevation Certificate utilizing the most current FEMA document confirming the required elevation of the structure prior to the issuance of a certificate of occupancy for the structure. 6. Prior to the issuance of the Flood Plain Development Permit the Applicant shall complete and record the amended plat for the property merging the two lots into a single developable lot. RESOURCE ENGINEERING I N C. Glenn Hartmann, Senior Planner Garfield County Community Development Department 108 8th Street, Suite 401 Glenwood Springs CO 81601 August 16, 2016 RE: Floodplain Development Permit Application Review, FDPA-04-16-8445, CMH Homes, Inc. - Chavez Residence Dear Glenn: At the request of Garfield County (GARCO), Resource Engineering, Inc. (RESOURCE) reviewed Floodplain Development Permit Application FDPA-04-16-8445 submitted by CMH Homes, Inc. for the Chavez residence. The application is for proposed new manufactured house to be located on Lots 8 & 9 of the Rifle Village South Subdivision. The property is located in within the 100 -Year Floodplain of Helmer Gulch designated as Zone AO Special Flood Hazard Area. Zone AO is defined as alluvial fan flooding area. The proposed project includes elevating the lowest finished floor to an elevation at least two feet higher than the adjacent ground (one foot above the flood depth). RESOURCE reviewed the submittal package including a letter report prepared by CIVCO Engineering, Inc. (CIVCO) dated May 4, 2016. RESOURCE's review comments are presented below. GENERAL BACKGROUND The proposed project is located within the alluvial fan of Helmer Gulch which has no permanent channel and flooding is therefore assumed to potentially occur anywhere on the fan area. This area has been analyzed and a flood depth of one foot with a velocity of 4 feet per second has been determined for the regulatory flood boundary. The effective map for the project is the FEMA Flood Insurance Rate Map Panel 080205-1353B dated January 3, 1986. Flood mitigation in this Zone is similar to a river floodplain, except that rather than elevating the lowest finished floor to one foot above a specific flood elevation, the criteria is one foot above a flood depth on the ground adjacent to the structure or adjacent to a fill pad that provides positive drainage away from the structure. REVIEW AND ANALYSIS RESOURCE reviewed the application for compliance with the applicable requirements in the 2013 GARCO Land Use and Development Code (amended July 21, 2014). These include Section 3-301 Floodplain Overlay Regulations, Section 4-109 Development in the 100 year Floodplain, and the general submittal requirement in Section 4-201 through 4- 203. RESOURCE generally concurs with the responses to each applicable section of the code provided in the CIVCO letter report, and such responses and proposed design meet the code requirements, except as noted below. 1. The anchoring system is listed as an over the top tie down in the CIVCO report, but the design drawings show a foundation system with tie straps to the floor joists. Consulting Engineers and Hydrologists 909 Colorado Avenue ■ Glenwood Springs, CO 81 601 Si (970) 945-8777 IN Fax (970)945-1137 Glenn Hartmann, Senior Planner June 17, 2016 Page 2 Both systems are acceptable, but the Applicant should clarify the design so that the floodplain permit and building permit are consistent for the project. 2. The grading plan on Sheet 2 of the CIVCO drawings calls out a high point on the west fence line with half the drainage flowing north and half flowing to the south. The existing topography does not appear to support this label. RESOURCE agrees with this approach so as to not impact the property to the west. It is recommended that the drawings indicate specific elevations at the high point and at the northwest and southwest corners for the contractor to provide the intended drainage concept. 3. The plans indicate a crawl space for the foundation system. The Applicant should address location, elevation and size of openings and address compliance with enclosure openings if appropriate. Specifically, the east side of the structure foundation could be subject to flooding in the crawl space. 4. The as -built Elevation Certificate should indicate one foot base flood depth rather than an elevation in Box B9.. Please call if you have any questions or need additional information. Sincerely, RESOURCE ENGINEERING, INC. Michael J. ion, P.E. Water Resources Engineer MJE/mmm 885-87.0 �iii3RESOURCE 13:Q