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HFLP-CS110222 C4 Federal Emergency Management Agency ° � / 4 Washington, D.C. 20472 L AND Of- February February 22, 2011 CERTIFIED MAIL IN REPLY REFER TO: RETURN RECEIPT REQUESTED Case No.: 10- 06 -3452R The Honorable Doug Stover Community: City of Coppell, TX Mayor, City of Coppell Community No.: 480170 P.O. Box 9478 Coppell, TX 75019 104 Dear Mayor Stover: This responds to a request that the Department of Homeland Security's Federal Emergency Management Agency (FEMA) comment on the effects that a proposed project would have on the effective Flood Insurance Rate Map (FIRM) for Dallas County, Texas, and Incorporated Areas (the effective FIRM for your community), in accordance with Part 65 of the National Flood Insurance Program (NFIP) regulations. In a letter dated September 2, 2010, Mr. Glen A. Dixon, P.E., CFM, Cotter Associates, LLC, requested that FEMA evaluate the effects that the proposed CLOMR, located on the Elm Fork of Trinity River at River Station 867 +93, project would have on the flood hazard information shown on the effective FIRM. The proposed project will impact the Elm Fork of Trinity River from approximately 1,280 feet downstream of Belt Line Road to approximately 40 feet upstream of Belt Line Road. The proposed project will include placement of fill along Elm Fork of Trinity River from approximately 660 feet downstream of Belt Line Road to approximately 40 feet downstream of Belt Line Road. The area of the proposed project is shown on the Dallas County, Texas, and Incorporated Areas FIRM numbers 48113C0155 J and 48113C0160 J, dated August 23, 2001. All data required to complete our review of this request for a Conditional Letter of Map Revision (CLOMR) were submitted with letters from Mr. Dixon. A preliminary countywide study is being conducted for Dallas County, Texas, and Incorporated Areas. Revised preliminary copies of the countywide FIRM and Flood Insurance Study (FIS) report, which present information from the effective FIRMs and FIS reports for your community and other areas within Dallas County, were submitted to your community for review on September 28, 2010. We reviewed the submitted data and the data used to prepare the effective FIRM for your community and determined that the proposed project meets the minimum floodplain management criteria of the NFIP. The submitted existing conditions HEC -RAS hydraulic computer model, dated September 2, 2010, based on updated topographic information, was used as the base conditions model in our review of the proposed conditions model for this CLOMR request. We believe that, if the proposed project is constructed as shown on the topographic work map, entitled "Proposed Conditions Floodplain Work Map," prepared by Cotter Associates, LLC, dated December 8, 2010, and the data listed below are received, a revision to the FIRM would be warranted. Our comparison of existing conditions to the effective flood hazard information revealed that the Base (1- percent- annual- chance) Flood Elevations (BFEs) increased compared to the effective BFEs for Elm Fork of Trinity River. The maximum increase in the BFE, 0.1 foot, occurred approximately 590 feet downstream of Belt Line Road. 2 As a result of the proposed project, the BFEs will decrease compared to the existing conditions BFEs for Elm Fork of Trinity River. The maximum decrease in the BFE, 0.3 foot, will occur approximately 40 feet upstream of Belt Line Road. As a result of the proposed project and updated topographic information, the BFEs will decrease compared to the effective BFEs for Elm Fork of Trinity River. The maximum decrease in the BFE, 0.2 foot, will occur approximately 40 feet upstream of Belt Line Road. As a result of the proposed project and updated topographic information, the width of the Special Flood Hazard Area (SFHA), the area that would be inundated by the base flood, will decrease compared to the effective SFHA width along Elm Fork of Trinity River. The maximum decrease in the SFHA width, approximately 850 feet, will occur approximately 680 feet downstream of Belt Line Road. As a result of the proposed project and updated topographic information, the width of the regulatory floodway will not change compared to the effective floodway width along Elm Fork of Trinity River. Upon completion of the project, your community may submit the data listed below and request that we make a final determination on revising the effective FIRM. • Detailed application and certification forms must be used for requesting final revisions to the maps. Therefore, when the map revision request for the area covered by this letter is submitted, Form 1, entitled "Overview and Concurrence Form," must be included. • The detailed application and certification forms listed below may be required if as -built conditions differ from the preliminary plans. If required, please submit new forms or annotated copies of the previously submitted forms showing the revised information. Form 2, entitled "Riverine Hydrology and Hydraulics Form" Hydraulic analyses, for as -built conditions, of the base flood; the 10- percent -, 2- percent -, and 0.2- percent - annual- chance floods must be submitted with Form 2. • As -built plans certified by a registered Professional Engineer, of all proposed project elements. • A topographic work map showing the revised and effective floodplain boundaries. • A copy of the annotated FIRM, at the scale of the effective FIRM, showing the revised base floodplain boundary delineation. • A preliminary countywide study for Dallas County is currently under review. The ongoing preliminary countywide study encompasses portion of the reaches for which this CLOMR is being issued. Upon completion of the project for which this CLOMR is issued, please comply with one of the following alternative requirements: o If a Letter of Map Revision (LOMR) for this proposed project is requested before the preliminary countywide study becomes effective, then the BFEs and SFHA boundary delineations must tie into the currently effective information, as shown on FIRM Panel 3 48113C0155 J, dated August 23, 2001. Therefore, for the LOMR that follows this CLOMR, please submit hydraulic models in which the revised BFEs and SFHA boundary delineations tie into the effective BFEs and SFHA boundary delineations at the downstream and upstream ends of the revised reach. o If a LOMR submittal for this proposed project is received after the preliminary countywide study has become effective, then the BFEs and SFHA boundary delineations must tie into that new effective information. Effective January 13, 2010, FEMA revised the fee schedule for reviewing and processing requests for conditional and final modifications to published flood information and maps. In accordance with this schedule, the current fee for this map revision request is $5,000 and must be received before we can begin processing the request. Please note, however, that the fee schedule is subject to change, and requesters are required to submit the fee in effect at the time of the submittal. Payment of this fee shall be made in the form of a check or money order, made payable in U.S. funds to the National Flood Insurance Program, or by credit card (Visa or MasterCard only). The payment, along with the revision application, must be forwarded to the following address: FEMA LOMC Clearinghouse 7390 Coca Cola Drive, Suite 204 Hanover, MD 21076 After receiving appropriate documentation to show that the project has been completed, FEMA will initiate a revision to the FIRM. Since the BFE decreases are too small, the FIS report will not be revised. This CLOMR is based on minimum floodplain management criteria established under the NFIP. Your community is responsible for approving all floodplain development and for ensuring all necessary permits required by Federal or State law have been received. State, county, and community officials, based on knowledge of local conditions and in the interest of safety, may set higher standards for construction in the SFHA. If the State, county, or community has adopted more restrictive or comprehensive floodplain management criteria, these criteria take precedence over the minimum NFIP criteria. If you have any questions regarding floodplain management regulations for your community or the NFIP in general, please contact the Consultation Coordination Officer (CCO) for your community. Information on the CCO for your community may be obtained by calling the Director, Mitigation Division of FEMA in Denton, Texas, at (940) 898 -5127. If you have any questions regarding this CLOMR, please contact the FEMA Map Information eXchange (FMIX), toll free, at 1- 877 -FEMA MAP (1- 877 - 336 - 2627). Sincerely, ' / 0 /1— Michael J. McGinn, CFM, Program Specialist For: Luis Rodriguez, P.E., Chief Federal Insurance and Mitigation Administration Engineering Management Branch Federal Insurance and Mitigation Administration 4 Enclosures cc: Mr. Kenneth M. Griffin, P.E. Director of Engineering City of Coppell Mr. Cesar Molina, P.E. Director of Engineering City of Carrollton Mr. Steve Parker, P.E., CFM Floodplain Administrator City of Dallas Mr. Garry Fennell, P.E., CFM Senior Civil Engineer City of Irving Mr. Glen A. Dixon, P.E., CFM Cotter Associates, LLC 104