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FIRM Case#92-06-006P-911115o� FILE GOP. Federal Emergency Managemen Washington, D.C. 20472 CERTIFIED MAIL RETURN RECEIPT REQUESTED Mr. M. Shohre Daneshmand, P.E. Acting City Engineer 255 Parkway Boulevard P.O. Box 478 Coppell, Texas 75019 Dear Mr. Daneshmand: NOV i 110 encv ey: Engineering (202) 646 -3403 F XC : Jew.., tt- C'1 IN REPLY REFER TO: 65 -PRE Date: November 15, 1991 Case Number: 92- 06 -006P Re: Grapevine Creek, Southwestern Boulevard to Interstate 635 Community: City of Coppell, Texas This is in regard to your request for a revision to the Flood Insurance Rate Map and /or Flood Boundary and Floodway Map for the referenced community. Our preacceptance review indicates that we do not have the minimum data we need to begin our evaluation of your request. The required data are described on the enclosed checklist and must be submitted to the following address before we can accept your request: Michael Baker Jr., Inc. 1420 King Street, Sixth Floor Alexandria, Virginia 22314 -2788 Attention: Mr. David P. Preusch, P.E. Unless otherwise directed by you in writing, we will keep the submitted data in our files. We will not begin a detailed review of the submitted data until we receive the requested data. When you write to us about your request, please include the case number (shown above) in your letter. If you have any questions about the requested data, please call Michael Baker, Jr., Inc., our Technical Evaluation Contractor, at (703) 838 -0400, and ask for the Revisions Coordinator for your state. Sincerely, William R. Locke Chief, Risk Studies Division Federal Insurance Administration Enclosure cc: The Honorable Mark Wolfe Mayor, City of Coppell `V�G��Y Mgn,9C� Federal Emergency Management Agency a Washington, D.C. 20472 O O DATA REQUEST CHECKLIST FOR REVISION TO FLOOD INSURANCE STUDY (FIS) /FLOOD INSURANCE RATE MAP (FIRM) BY LETTER OF MAP REVISION (LOMR) OR PHYSICAL MAP REVISION Date: November 15, 1991 Requestor: Mr. M. Shohre Daneshmand, P.E. Community: City of Coppell, Texas Re: Grapevine Creek, Southwestern Case Number: 92- 06 -006P Boulevard to Interstate 635 The data identified below as "Required" must be submitted for our review. The data identified as "Received" should not be resubmitted. References to the sections of the National Flood Insurance Program (NFIP) regulations that establish specific requirements for supporting data are included as appropriate in the checklist entries. All analyses submitted must be certified by a registered professional engineer. All topographic data submitted must be certified by a registered professional engineer or licensed land surveyor. The meaning of "certification" as it applies to the types of required supporting data is given in Paragraph 65.2(b) of the NFIP regulations. The required data should be submitted to the following address: Michael Baker Jr., Inc. 1420 King Street, Sixth Floor Alexandria, Virginia 22314 -2788 Attention: Mr. David P. Preusch, P.E. 1. 2. 3. Description of Data A concise description of the nature and extent of the requested revision. Evidence that the Chief Executive Officer (CEO) of the affected community, or an official designated by the CEO, was asked to submit the revision request. (See Section 65.4 of the NFIP regulations.) A general description of the changed hydrologic Required Received X X conditions on which the revision request is based. (See Paragraph 65.6(c)(1)(i) of the NFIP regulations.) N/A 4. A general description of the changed hydraulic conditions, including channel modifications or other projects, on which the revision request is based. (See Paragraph 65.6(c)(2)(i) of the NFIP regulations.) X 5. New hydrologic analysis, including a brief description of the methodology used, for the -year flood(s) for (See Paragraph 65.6(a)(7) of the NFIP regulations.) N/A 6. Evidence that the appropriate local, State, or Federal agency (i.e., ) has approved the new hydrologic analysis, including the resulting peak discharge values. X 7. Printouts (including full input and output listings) from a calibration model, produced by the requestor, that duplicates the hydraulic computer model used to determine the 10 -, 50 -, 100 -, and 500 -year water- surface elevations shown for Grapevine Creek in the effective FIS report and on the effective FIRM. (See Paragraph 65.6(a)(8) of the NFIP regulations.) The calibration model may be either the FIS Model, reproduced on the requestor's equipment, or a model that yields computed water- surface profiles that duplicate the flood profiles shown for Grapevine Creek in the effective FIS report. X Description of Data Required (Received 8. Printouts (including full input and output listings) from a calibration model, produced by the requestor, that duplicates the hydraulic computer model used to determine the limits of the 100 -year floodway shown for Grapevine Creek on the effective Flood Boundary and Floodway Map (FBFM) /FIRM. (See Paragraph 65.6(a)(8) of the NFIP regulations.) The calibration model may be either the FIS floodway model, reproduced on the requestor's equipment, or a model that yields the computed floodway widths and water- surface elevations presented in the Floodway Data Table for Grapevine Creek in the effective FIS report. 9. Printouts (including full input and output listings) from a revised hydraulic model for the 10 -, 50 -, 100 -, and 500 -year water- surface elevations on Grapevine Creek. The revised model must be created from the calibration model (Item 7) and must meet the requirement(s) listed below. X The model must be based on the same peak discharge values used in the calibration model (Item 7). The model must be based on the peak discharge values determined in the new hydrologic analysis (Item 5). X The model must account for the effects of the changed hydraulic conditions on which the revision request is based. In addition, the revised model must account for the effects of any encroachments that have occurred in the 100 -year floodplain since the FIS hydraulic model was developed and must cover a sufficient Length of Grapevine Creek so that the water- surface elevations computed at cross sections upstream and downstream of the revised reach will match those shown at the same cross sections on the Flood Profiles in the effective FIS report within approximately 0.5 foot. All changes to the input data in the calibration model (Item 7) must be highlighted on the printouts. (See Paragraph 65.6(a)(8) of the NFIP regulations.) X KI Description of Data Required 10. A hydraulic analysis, including a brief description of the methodology used, for the 100 - year flood on Grapevine Creek. (See Paragraph 65.6(a)(9) of the NFIP regulations.) 11. Printouts (including full input and output listings) from a revised hydraulic model for the 100 -year floodway on Grapevine Creek. The revised model must be created from the calibration model (I em 8) and must meet the requirements listed below. X The model must be based on the 100 -year peak discharge value(s) used in the calibration model (Item 8). The model must be based on the 100 -year peak discharge value(s) determined in the new hydrologic analysis (Item 5). X The model must account for the effects of the changed hydraulic conditions on which the revision request is based. In addition, the revised model must account for the effects of any encroachments that have occurred in the 100 -year floodplain since the FIS floodway model was developed and must cover a sufficient length of Grapevine Creek so that the water- surface elevations and floodway widths computed at cross sections upstream and downstream of the revised reach will match those shown at the same cross sections on the Flood Profiles and Floodway Data Table in the effective FIS report. The revised model must be based on the equal conveyance reduction method unless agreements have been made with affected property owners that an alternative method would be used. The net effect of the changed hydraulic conditions, the encroachments that have occurred since the FIS floodway model was developed, and the revised floodway limits must not increase the computed 100 -year water- surface elevations by more than 1.0 foot above those computed in the calibration model (Item 7) or those computed in the revised model (Item 9), whichever are lower. (See Paragraph 65.7(b)(4) of the NFIP regulations.) Received M F;1 Description of Data Required (Received 12. Documentation, as shown below, concerning the approval of the revised floodway. (See Paragraphs 65.7(b)(1), (2), and (3) of the NFIP regulations.) Copy of the public notice distributed by the community stating the community's intent to revise the floodway or a statement by the community that it has notified all affected property owners and affected adjacent jurisdictions. Copy of a letter notifying the appropriate State agency of the floodway revision. Documentation of the approval of the revised floodway by the appropriate State agency. N/A 13. Corporate limit map and /or annexation ordinances that reflect the current community boundaries. N/A 14. A topographic map that shows the revised 100 -year floodplain and floodway boundaries, the locations and alignments of all cross sections used in the revised hydraulic models (Items 9 and 11), stream alignments, road alignments, and the community boundaries. The revised 100 -year floodplain and floodway boundaries must tie into those shown on the effective FIRM and FBFM upstream and downstream of the revised reach. The scale and topographic definition of the map must be sufficient to provide reasonable accuracy, and the map must be certified by a registered professional engineer. (See Paragraphs 65.6(a)(11) and 65.7(b)(5) of the NFIP regulations.) 15. "As- built" plans, certified by a registered professional engineer, for all project elements, specifically channel realignment and channel drop structure. X the City With A Beautiful Future P.O. Box 478 Coppell, Texas 75019 214 - 462 - 0022 1UL) FACSIMILE NO. 214/393 -0948 FAX MAIL COVER PAGE PLEASE DELIVER THE FOLLOWING PAGES TO: NAME: Z�Z— —e I C4ZSe—�:7 P1 FIRM: b'0- r 4- � i, Y i" FAR r0: -7 E%TENTION: < TRANSMITTED BY: OUR FAX NO.:214/393 -0948 NUMBER OF PAGES (INCLUDING COVER SHEET:) - REMARKS Y YOU DO THANK YOU. ALL SOOK AS SF.1�IW THIS