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Billingsley-CS050525Federal Emergency Management Washington, D.C. 20472 MAY 2 5 2005 CERTIFIED MAll, P, ETURN RECEIPT REQUESTED IN REPLY REFER TO: Case No.: 04-06-A148R CITY MANAGER CITY OF COPPE~,I~, , Thc Honorable Doug Stovcr Mayor, City of Coppell 255 Parkway Boulevard Coppell, TX 75019 Cormnunity: City of Coppell, TX Community No.: 480170 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) and Flood Insurance Study (FIS) report/'or Dallas County, Texas and Incorporated Areas (the effective FIRM and FIS report lbr your community), in accordance with Part 65 of the National Flood Insurance Program (NFIP) regulations, lu a letter dated August 6. 2004, Mr. Walter E. Skipwith, P.E., Vice President, Halff Associates, Inc., requested that FEMA evaluate the effects that the proposed Billingsley Tract project along Grapevine Creek from approximately 2,100 feet upstreana of Beltline Road to approximately 300 feet upstream of MacArthur Boulevard would have on the flood hazard inlbnnation shown on tim effective FIRM and F1S report. The proposed project will include updated topographic information, placement of fill in the left overbank of Grapevine Creek, and creation of a swale along the filled bank to coxnpensate lbr thc conveyance loss caused by the landfill. All data requircd to complete our review of this request lbr a Conditional Letter of Map Revision (CLOMR) were submitted with letters from Mr. Russell P. Erskinc, ttydrologist, also with Halfl' Associates, Inc., and Mr. Skipwith. Because this revision request also affects thc Cities of Dallas and Irving, separate CLOMRs fbr those communities were issued on the same date as this CLOMR. We reviewed the submitted data and the data used to prepare thc effective FIRM tbr your community and determined that the proposed project meets the mininmm floodplain management criteria of the NFIP. Tile submitted existing conditions tfEC-RAS hydraulic computer model, dated June 2004, based on updated topographic inlbrmation, was used as the base conditions model in our review of the proposed conditions inodel lbr this CLOMR request. We believe that. if the proposed project is constructed as shown on the work map entitled "Floodplain and Floodway Delineations," prepared by HalffAssociates, Inc., dated April 14, 2005, and the data listed below are received, a revision to the FIRM would be warranted. ()ur comparison of existing conditions to the effective data revealed lhat as a result of the updated topographic inlbrulation, the elevations of the flood having a l-percent chance of being equaled or exceeded in any given year (base flood) increased and decreased along Grapevine Creek lbr the project area and your community. 'File maximum increase in Base Flood Elevation (BFE), 1.8 feet, occurred approximately 1,600 feet upstream of MacArthur Boulevard lbr the project area and your community. The maximum decrease in BFE, 2.4 feet, occurred approximately 150 feet upstream of Beltline Road for the project area and your community. As a result of the proposed project, the BFEs lbr Grapevine Creek will increase and decrease compared to the existing conditions BFEs lbr thc project area and your community. Thc maximum increase in BFE, 0.1 lbot, will occur approximately 120 feet upstream of Beltline Road for the project area and your community. Thc maximum decrease in BFE, 1.0 lbot, will occur approximately 1,700 feet downstream of l',eltlme Road for the project area and your commmfity. As a result of the proposed project, the BFEs lbr Grapevine Creek will increase and decrease conrpamd to the effective BFEs. The maximum increase ill BFE, 1.7 l~eet, will occur approximately 1,600 feet upstream of MacArthur Boulevard for the project area and your community. The maxinmm decrease in BFE, 2.5 feet, will occur approximately 150 fcet upstream of Beltline Road for the project area and your community. As a result of the proposed project, the width of the Special Flood Hazard Area (SFHA), the ama that would be inundated by the base flood, along Grapevine Creek will increase in some areas and decrease in nther areas compared to the effective SFHA width. The lnaximum increase in SHFA width for the project ama, approximately 120 feet, will occur approximately 2,000 feet downstream of Beltline Road. The maximum decrease in SHFA width lbr thc project area, approximately 830 feet. will occur approximately 2,600 feet downstream of Beltline Road. The ~naximum decrease in SHFA width lbr your community, approximately 700 feet, will occur approximately 1,100 feet upstream of MacArthur Boulevard. As a result of the proposed project, the width of the regulatory floodway will increase in some areas and decrease in other areas compared to the effective floodway width. Tile maximum increase in floodway width for the project area, approximately 1 I 0 feet, will occur approximately 1,400 feet downstream of Beltline Road. The maximum increase in floodway width for yx)ur community, approximately 60 l;eet, will occur approximately 1,400 feet downstream of Beltline Road. The maximum decrease in floodway width lbr the project area, approxiinately 360 teet, will occur just downstream of Beltline Road. The maximum decrease in floodway width for your community, approximately 300 feet, will occur just upstream of Beltline Road. Upon completion of thc project, your community may submit the data listed below and request that we make a final deterlnmation on revising the effective FIRM and FIS report. Detailed application and certification lbm~s, which were uscd in processing this request, must be used lbr requesting final revisions to thc nraps. Therefore, when the map revision request tbr tile area covered by this letter is submitted, Form 1, entitled "Overview & Concurrence Fonn," must be included. (A copy of this lbml is enclosed.) The detailed application aud ccrlification lbrms listed below may be requircd if as-built conditions differ l?om the conceptual plans. If required, pleasc submit ne~v tbm~s (copies of ~vhich are enclosed) or annotated copies of the previously submitted forms showing the revised information. Form 2, entitled "Riverme 1 lydrology & tlydraulics Foml" l:om~ 3. entitled "Riverine Structures Form" Hydraulic analyses, lbr as-built conditions, of the base flood; the floods having a 10-, 2-, and 0.2-percent chance of being equaled or exceeded in any given year; and the regulatory floodway, together with a topographic work map showing the revised floodplain and floodway boundaries, must be sub~nitted with Form 2. Eflkctive September 1, 2002, FEMA revised the lee schedule Ibr reviewing and processing requests lbr conditional and final modifications to published flood inlbnnation and maps. In accordance with this schedule, the current fcc for this map revision request is $3,800 and must be received betbre we can begin processing the request. Please note, however, that the tee schedule is subject to change, and requesters are required to submit the tee in effect at the time of the submittal. Payment of this lke shall be made iu the form of a check or money order, made payable in U.S. funds to the National Flood Insurance Program, or by credit card. The payment must be forwarded to the following address: Federal Emergency Management Agency Fee-Charge Syste~n Administrator P.O. Box 22787 Alexandria, VA 22304 · As-built plans, certified by a registered professional engineer, of all proposed project elements · Community acknuwledgtnent of the map revision request A copy of the public notice distributed by your community stating its intent to revise the regulatory floodway, or a statement by your community that it has notified all affected property owners and affected adjacent jurisdictions A certified annotated FIRM, at the scale of the effective FIRM, that shows tile revised base floodplain and floodway boundaries delineated ou the subnfitted work map Please subnfit documentation of individual legal notice sent to all property owners affected by any widening and/or shilling of the base floodplain tbr Grapevine Creek and/or increases in BFE. This notice must include an explanation of the effects of the proposed project. After receiving appropriate dncumentation to show that the project has been completed, FEMA will initiate a revision to the FIRM FIS reprat. Because the BFEs would change as a result of the project, a 90-day appeal period would bc initiated, during which comnmnity officials and interested persons may appeal thc revised BFEs based on scientific or technical data. This CLOMR is based on nfinimum floodplaiu managcmcnt criteria established under tile NFIP. Your comnmnity is responsible fbr approving all tloodplain 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 sal;cty, may set higher standards for construction in the SFItA. Il'the State, county, or community }las adopted more restrictive or comprehensive floodplain management criteria, these criteria take precedence over tile miuimum NFIP criteria. If you have any questions regarding fioodplain management regulations tbr your community or the NFIP in general, please contact thc Consultation Coordination Officer (CCO) lbr your community. Inlbnnation on the CCO for your community may be obtained by calling the Director, Federal Insurauce and Mitigation 4 Division of FEMA in Denton, Texas, at (940) 898-5127. If you have any questions regarding this CLOMR, please call our Map Assistance (?enter, toll l?ee, at 1-877-FEMA MAP (1-877-336-2627). Sincerely, Max H. Yuan, P.E., Project Engineer ttazard Identification Section Mitigation Division Emergency Preparedness and Response Directorate Enclosures CC: ]'he Honorable Laura Miller Mayor, City of Dallas The Honorable Joe Putnam Mayor City of Irving Mr. Ken Griffin, P.E. City Engineer City of Coppell Mr. Gary Fennell Floodplain Administrator City of hwing Mr. Steve Parker Floodplain Manager City of Dallas Mr. Walter E. Skipwith, ILl';. Vice President Halff Associates, lnc. Mr. Henry Billingsley Mr. Russell P. Erskinc f lydrologist l lalff Associates, Inc. For: Doug Bellomo, P.E., Chief Hazard Identification Section Mitigation Division Emergency Preparedness and Response Directorate