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St Andrews Est-CS031003Evans Engineering 1417 W. Main Street, Suite 100B - Carrollton, Texas 75006 Mailing Address: P.O. Box 165539 - Irving, Texas 75016 Tel: 214-929-2763 Fax: 972-594-8263 October 3, 2003 Mr. Kenneth M. Griffin, P.E. Director of Engineering & Public Works City of Coppell 255 Parkway Blvd. Coppell, Texas 75019 Re: Request for a Conditional Letter of Map Revision (CLOMR) on Old Denton Creek for "St. Andrews Estates" Dear Mr. Griffin: Enclosed please find a report and CLOMR application regarding the proposed improvements along Denton Creek, specifically the channel designated as "Old Denton Creek." This report is submitted on behalf of St. Andrews Land Company Ltd. and contains the FEMA forms and requisite technical data for issuance of a Conditional Letter of Map Revision Based on Fill (CLOMR-F.) Please review the report, endorse the application by signing MT-1 Form 3 where indicated, and notify the undersigned that the documents may be forwarded to the FEMA contractor for Region VI (PBS&J) with the appropriate fee. A copy of the report is enclosed for your file. Included in this report are "hard copies" of output from the HEC-RAS hydraulic model, a disk containing input data files, and revised flood plain mapping. Application and Certification forms are included in Section I1. This submission is in support of the development application for the aforementioned project submitted to the City of Coppell in August 2003. The subject flood plain is delineated as shown in Community-Panel No. 480170-0010, as revised by LOMR No. 97-06-503P. The base hydraulic model and flood plain study for this portion of Old Denton Creek were those conducted by Nathan D. Maier Engineers, Inc. and approved by FEMA letter dated July 23, 1997. This effective base FIS model (HEC-2 data) was obtained from Ms. Teresa Turner, Department of Engineering and Public Works, City of Coppell. Please note that no changes to the creek's hydrology or the channel's floodway are proposed by the subject development. The only proposed fill is in a small part of the flood plain which extends along a minor tributary to Old Denton Creek. The model for the proposed fill in the flood plain indicates that no significant change in flood plain widths and no increase in 100-year base flood elevation will occur at off-site downstream or upstream locations. Therefore, a CLOMR-F application is submitted for a map revision to remove the flood plain proposed to be filled. If you have any technical questions on this report, please contact the undersigned at (214) 929-2763. Thank you for your consideration of this request. Sincerely, J. David Evans, P.E. Enclosure: Report: "Request for a Conditional Letter of Map Revision (CLOMR) for St. Andrew Estates," September 29, 2003 (with Attachments). cc: Mr. Peter Hennessey, P.E., Hennessey Engineering, Inc., Carrollton, Texas