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FS9905-CS 990712Federal Emergency Management Agency Washington, D.C. 20472 JUL 12 1999 CERTIFIED MAIL RETURN RECF. H~T REQUESTED IN REPLY REFER TO: Case No.: 99-06-1535R The Honorable Candy Sheehan Mayor, City of Coppell 255 Parkway Boulevard Coppell, TX 75019 Community: City of Coppell, Texas Community No.: 480170 104 Dear Mayor Sheehan: This responds to a request that the Federal Emergency IVhnngement Agency (FEMA) comment on the effects that a proposed project would have on the effective Rood Ins~ Rate Map (FIRM) for your community in accordance with Part 65 of the National Flood Insurance Program (NFIP) regulations. In a letter dated June 23, 1999, Mr. Ronald W. Morrison, P.E., C.F.M., Morrison Hydrology Engineering, Inc., requested that FEMA evaluate the effects that proposed piacement of fill along Elm Fork of Trinity River (Elm Fork) and proposed excavation associated with proposed constniction of the River Chase Elementary Schcol would have on the flood hazard information shown on the effective FIRM and Flood Insurance Study CFIS) report. The proposed fill will be placed appwximately 2,300 feet south of Sandy Lake Road and approximately 800 feet east of Macarthur Boulevard, and the proposed excavation will occur approximately 1,800 feet south of Sandy Lake Road and from approximately 300 feet east to approximately 700 feet east of Macarthur Boulevard. All data required to complete our review of this request for a Conditional Letter of Map Revision (CLOIV!R) were submitted with letters from Mr. Morrison. We have completed our review of the submiued data, the flood data used m prepare the effective FIRM, and data submiRed to reflect existing conditions in support of a CLOMR dated June 7, 1999, for your community. The submitted existing conditions HEC-2 hydraulic computer model, dated April 24, 1999, 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 "River Chase Elementary School, Proposed 100 year Floodplain," contained in the report entitled "Flood Study in support of a Conditional Letter of Map Revision for River Chase Elementary School, City of Coppell, Texas," prepared by Morrison Hydrology Engineering, Inc., dated June 15, 1999, and the data listed below are received, a revision to the FIRM would be warranted. As a result of the more detailed topographic information, the elevations of the flood having a 1-percent chance of being equaled and exceeded in any given year (base flood) and the width of the Special Flood Hazard Area (SFtIA), the area that would be inundated by the base flood, along Elm Fork decreased in the vicinity of the proposed project compared to the effective base flood elevations (EFEs) and SFHA width. Because the proposed placemere of fill and excavation along Elm Fork will occur largely within the floodplain of the flood having a 0.2-porcent chance of being equaled or exceeded in any given year, the proposed project will not affect the existing conditions BFEs. The widths of the SFHA and the regulatory floodway along Elm Fork will not change as a result of the proposed project. Upon completion of the project, your community may submit the d=t~ listed below and request that we make a final determination on revising the effective FIg report and FIRM. Effective March 1, 1999, FEMA revised the fee schedule for reviewing anti processing requests for conditional and final modifications to published flood information and maps. In accordance with this schedule, th~ fee for your rnnp revision request will be $3,400 and must be received before we can begin processing your request. 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 ln,~rance Program, or by credit card. The payment must be forwarded to the following address: Federal Emergency Management Agency Fee-Collection System Administrator P.O. Box 3173 Merri~eld, VA 22116-3173 As-bulk plans, certified by a registered professional engineer, of all proposed pwject elements · Community acknowledgment of the map revision request Certification that all fill placed in the currently effective base floodplain and below the proposed BFE is compacted to 95 percent of the maximum density obtainable with the Standard Proctor Test method issued by the American Society for Testing and Materials (ASTM Standard D-698) or an acceptable equivalent mathod for all areas to be removed from the base floodplain This CLOMR is based on minimum ~oodphin management criteria established under the NFIP. Your community is responsible for approvin~ all floodplain development, and for ensuring all ~ pennits required by Federal or State law have been received. State, county, and community o~icla|~ 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 conunity has adopted more restrictive or comprehensive floodplain management criteria, these criteria take precedence over the minimum NPIF 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 commu.nity. Information on the CCO for your community may be obtained by contacting the Director, Mitigation Division of FEMA in Denton, Texas, at (940) 898-5127. If you have any technical questions regarding this CLOMR, 3 please contact Mr. Alan Johnson of our staff in Washington, DC, either by telephone at (202) 64(>-3403 or by facsimile at (202) 6464596. Sincerely, Alan A. Johnson, P.E., Project Engineer Hazards Study Branch ~ Mitigation Directorate Enclosure(s) CC: Mr. Kenneth M. Griffin, P.E. Director of Engineering and Public Works City of Coppert Matthew B. Miller, P.E., Chief H, 7~rds Study Branch Mitigation Directorate