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Alexander Ct-CS080114 Page 1 of 1 Ken Griffin - Fwd: FEMA letter rec'd today From: To: Date: Subject: CC: Ken Griffin john.hawkins @tx.rr.com 1/14/2008 4:14 PM Fwd: FEMA letter rec'd today cadkins@toase.com; Clay Phillips; David Dodd; dritter@toase.com; Marcie Diamond; Mike Boyd National Flood Insurance Program.pdf Attachments: Mr. Hawkins I'm unsure if you have spoken with Mike Boyd, but the City received this letter from FEMA on Friday January 11 tho I noticed you were not copied on it, so I'm forwarding it to you. It seems FEMA is requesting additional information. I spoke with Mr. Boyd on Friday but he had not seen the letter yet so he couldn't comment on the items requested. Ken Griffin >>> Rhonda Adloo 1/11/2008 10:24 AM >>> RE: Alexander Court Flood Study file://C:\Documents and Settings\rbrother\Local Settings\Temp\XPgrpwise\478B8A56City... 1/15/2008 NATIONAL FLOOD INSURANCE PROGRAM FEMA NATIONAL SERVICE PROVIDER January 7,2008 Mr. Michael H. Boyd, P.E. Executive V ice President Nathan D. Maier Consulting Engineers, Inc. 8080 Park Lane, Suite 600 Dallas, TX 75231 IN REPLY REFER TO: Case No.: 07-06-2203P Community. City of Coppell, TX Community No.: 480170 316-AD Dear Mr. Boyd: This is in regard to your submittal dated November 14,2007, concerning a July 26,2007, request that the Department ofHomeJand Security's Federal Emergency Management Agency (FEMA) issue a revision to the Flood Insurance Rate Map (FIRM) for the Dallas County, Texas and Incorporated Areas. Pertinent infonnation about the request is listed below. Identifier. Grapevine Creek Flooding Source: Grapevine Creek FIRM Panel(s) Affected: 48113C0155 J The data required to complete our review, which must be submitted within 90 days of the date of this letter, are listed on the enclosed summary. If we do not receive the required data within 90 days, we will suspend our processing of your request. Any data submitted after 90 days will be treated as an original submittal and will be subject to all submittal/payment procedures, including the flat review and processing fee for requests of this type established by the current fee schedule. A copy of the notice summarizing the current fee schedule, which was published in the Federal Register, is enclosed for your information. FEMA receives a very large volume of requests and cannot maintain inactive requests for an indefinite period of time. Therefore, we are unable to grant extensions for the submission of required data for revision requests. If a requester is informed by letter that additional data are required to complete our review of a request, the data/fee must be submitted within 90 days of the date of the letter. Any fees already paid will be forfeited for any request for which the requested data are not received within 90 days. If you have general questions about your request, FEM A policy, or the National Flood Insurance Program, please call the FEMA Map Assistance Center, toll free, at 1-877-FEMA MAP (1-877-336-2627). If you have specific questions concerning your request, please contact your case reviewer, Mr. KathirveJ Arumugam. bye-mail at kathirvel.arumugam@mapmodteam.com or by telephone at 38111 Eisenhower Avenue. Alexandria, VA 223D4-#UZ5 PH:1-471-FEMA MAP FX: 70J.tI6O.8125 The Mapping on Demand Team, under contract with the Federal Emergency Management Agenc::y Is the National Service Provider for the National Flood Insurance Program . 2 (703) 960-8800, extension 3026. You may also contact the Revisions Coordinator for your State, M. Saleem Ashraf, Ph.D., P.E., bye-mail at saleem.ashraf@mapmodteam.com or by telephone at (703) 317-6225. Sincerely, ~ @4W1 Syed Qayum, CFM National LOMR Technical Manager Michael Baker Jr., Inc. Enclosures cc; Mr. Ken Griffin, P.E. Director of Engineering Department ofPubJic Works City of Coppell NATIONAL FLOOD INSURANCE PROGRAM FEMA NATIONAL SERVICE PROVIDER Summary of Additional Data Required to Support a Letter of Map Revision Case No.: 07-06-2203P Requester: Mr. Michael H. Boyd, P.E. Community: City of Coppell, TX Community No.: 480170 The issues listed below must be addressed before we can continue the review of your request. I . Please submit a copy of the individual legal notice sent to all property owners affected by any widening and/or shifting of the Special Flood Hazard Area, the area that would be inundated by the base (I -percent annual-chance) flood, and/or any increases in the Base Flood Elevation (BFE). The notice must include a descriptive explanation of these changes. Please follow the template for this letter on page I 7 of the instructions for the MT - 2 Application/Certification forms, which may be accessed at http://www.fema.gov/pdflthm/mt-2.pdf 2. Paragraph 65.6(a)(2) of the National Flood Insurance Program regulations states that to avoid discontinuities between revised and unrevised flood data, hydraulic analyses must have a logical transition between revised BFEs and those developed previously for areas not affected by the revision. Our review revealed that the submitted post-project conditions hydraulic model for Grapevine Creek does not tie into the effective hydraulic analysis within 0.5 foot at the upstream end of the revised reach. Please provide a revised hydraulic model for Grapevine Creek that ties into the effective hydraulic analysis within 0.5 foot, or within 0.0 feet if practical. 3. Please address the following comments regarding the submitted post-project conditions HEC-RAS hydraulic models, or provide an explanation for each. a. Our review revealed that the contraction and expansion loss coefficients at Cross Sections 25550 and 27620, which were 0.1 and 0.3, respectively, do not reflect modeling practices generally accepted in HEC-RAS. Contraction and expansion loss coefficients of 0.3 and 0.5, respectively, may be more appropriate. b. Please revise the post-project conditions hydraulic model so that the left and right encroachment stations at Cross Sections 23900,27400, and 27900 are located at the left or right channel bank stations or in the tloodway funge, the area between the channel bank station and the limits of the base floodplain. 4. The submitted work map entitled, "Sheet I, Floodplain Wolk Map," dated November 2007, prepared by your firm, does not include the flow line, flood way and floodplain delineations between Cross Sections 27900 and 30130. Please submit a revised topographic work map, certified by a registered professional engineer, using an appropriate scale, that reflects any changes resulting from Items 2 and 3 above, and contains all applicable items listed in Section C of Application/Certification Form 2, entitled "Riverine Hydrology & Hydraulics Form," including the following: a. The effective boundary delineations of the regulatory tloodway, base floodplain, and 0.2-percent-annual-chance floodplain and how they tie into the post-project conditions boundary delineations at the upstream and downstream limits of the revision area; 3601 ElHllIIoww AlIWlUll, Alexandria, VA 22~ PH:1.JT7-FEMA MAP FX: 703'-.'125 The Mapping on Demand Team, under contract with the Federal Emergency Management Agency, is the National Service Provider for the National Flood Insurance Program 2 b. The topographic information, with labeled contour lines. used for the floodway and floodplain boundary delineations; c. The locations and alignments of the cross sections used in the hydraulic analysis; d. A north arrow. the scale, and the vertical datum; and e. The flow line used in the hydraulic model. If digital data are submitted, please include any supporting documentation or metadata with the data submittal, including relevant projection infonnation. Current mapping standards use the Universal Transverse Mercator (UTM) projection and State Plane Coordinate System. in accordance with Federal Emergency Management Agency mapping specifications. Data not submitted in ESRI mapping fonnat can be submitted in any supported data format, which includes AutoCAD. Microstation, and MapInfo. 5. Please submit a copy of a certified, annotated Flood Insurance Rate Map (FIRM), at the scale of the effective FIRM, which reflects any revisions made to the floodway and floodplain boundary delineations as a result ofItems 2 through 4. Please send the required data directly to us at the address shown at the bottom of the first page. For identification purposes. pleasc include the case number referenced above on all correspondence.