Billingsley-CS070312~4AAr,~~
Mr. Brandon A. Luedke, E.I.T.
}ialff Associates, Inc.
8616 Northwest Plaza Drive
Dallas, TX 75225
r
~
M
~ ~
~~l'~JVD S~GJiI
FEMA NATIONAL SERVICE PROVIDER
March 12, 2007
IN REPLY REFER TO:
Case No.: 06-06-BE95P
Communities: Cities of Coppell, Dallas,
and Irving, TX
Community Nos.: 480170, 480171, and 480180
316-AD
Dear Mr. Luedke:
This is in regard to your request dated July 10, 2006, that the Department of Homeland Security's Federal
Emergency Management Agency (FEMA) issue a revision to the Flood Insurance Rate Map (FIRM) for
Dallas County, Texas and Incorporated Areas. Pertinent information about the request is listed below.
Identifier:
Flooding Source:
FIRM Panel(s) Affected:
158.6-Acre Billingsley Tract
Grapevine Creek
4811300155 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
submittaUpayment 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 fees 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.
3601 Eisenhower Avenue, Alexandria, VA 22301-6425 PH:1-877-FEMA MAP FX: 703.960.9125
NATIONAL FLOOD INSURANCE PROGRAM
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
If you have general questions about your request, FEMA 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 call the Revisions Coordinator for your State,
M. Saleem Ashraf, Ph.D., P.E., who may be reached at (703) 960-8800, ext. 5229.
Sincerely,
Sheila M. Norlin, CFM
National LOMC Manager
Michael Baker Jr., Inc.
Enclosures
cc: Mr. Kenneth M. Griffin, P.E.
Director of Engineering and Public Works
Engineering Department
City of Coppell
Mr. Steve Parker
Floodplain Manager
City of Dallas
Mr. Garry Fennell
Senior Civil Engineer
City of Irving
Mr. Henry Billingsley
Partner
Billingsley & Co.
Mr. Walter E. Skipwith, P.E.
Vice-President
Halff Associates, Inc.
QNtry
°' NATIONAL FLOOD INSURANCE PROGRAM
so,,~ 4'.~ FEMA NATIONAL SERVICE PROVIDER
~~AND S~GJ
Summary of Additional Data Required to Support a
Letter of Map Revision
Case No.: 06-06-BE95P
Communities: Cities of Coppell, Dallas,
and Irving, TX
Requester: Mr. Brandon A. Luedke, E.I.T.
Community Nos.: 480170, 480171, and 480180
The issues listed below must be addressed before we can continue the review of your request.
Our review of the post-project conditions model revealed an increase in the elevation of the flood
having a 1-percent chance of being equaled or exceeded in any given year (base flood) at
Cross Sections 13339, 13620, 13829, and 14170 when compared to the pre-project conditions model.
The construction of a project in the effective regulatory floodway may not increase the Base Flood
Elevations by more than 0.00 foot, according to Paragraph 60.3(d)(3) of the National Flood Insurance
Program (NFIP) regulations. Please revise the pre-project conditions model so that there is no increase
at any cross section in the post-project conditions model.
Our detailed review of the post-project conditions hydraulic analysis for Grapevine Creek and the
submitted undated topographic work map entitled "Fooodplain Reclamation Project Grapevine Creek-
FIS," prepared by your firm, revealed that the base floodplain and floodway topwidths computed in the
post-project conditions hydraulic analysis at Cross Sections 11588, 12402, 12820, 13829, and 14170
do not match the approximate conditions floodplain and floodway topwidths shown on the topographic
map. Please revise the HEC-2 models accordingly, or provide explanations for the discrepancies.
3. Please submit an annotated Flood Insurance Rate Map (FIRM), at the scale of the effective FIRM, that
shows the revised conditions base floodplain and floodway boundary delineations, as shown on the
submitted work map, and how they tie into the base floodplain and floodway boundary delineations
shown on the effective FIRM at the downstream and upstream ends of the revised reach.
Please send the required data directly to us at the address shown at the bottom of this page. For
identification purposes, please include the case number referenced above on all correspondence.
3601 Eisenhower Avenue, Alexandria, VA 223046425 PH:1-877-FEMA MAP FX: 703.960.9125
The Mapping on Demand Team, under contract with the Federal Emergency Management Agency, is the
National Service Provider for the National Flood Insurance Program