ST1002-SY080221
Freese
und Nichols, Inc.
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Engineers
Environmental Scientists Architects
1701 North Market Street, Suite 500 LB 51 Dallas, TX 75202
214920-2500
214 920-2565 fax
www.freese.com
February 21, 2008
Frank Pagano
Director, FEMA Mitigation Division
800 N. Loop 288
Denton, TX 76209
RE: FEMA Map Modification for the City of Coppell
Tributary G-l
Dear Frank Pagano:
The City of Coppell (City) has retained the services of Freese and Nichols, Inc. (FNI) to evaluate the
DFIRM floodplain for Tributary G-l currently a Zone A. FNI compared the new FEMA mapping to the
existing FIRM and compared that delineation to recent hydrologic and hydraulic studies provided by the
City. Recent design of Coppell Road and Bethel Road has required developers to determine a 100-year
water surface elevation to reflect proposed changes. These studies were provided to FNI by the City and
were reviewed. It was detennined by FNI that these studies represent the most current hydrologic and
hydraulic infonnation.
Based on the hydraulic models provided, the existing 1 OO-year base flood elevation upstream Bethel Road
was 507.19 ft and approximately 504.93 upstream of Coppell Road and 504.23 downstream. FNI
obtained the City current 2-ft contours and delineated the existing 1 OO-year water surface. The
comparison between the three (3) sources, the FIRM, DFIRM and City provided data, is provided in the
attached Figure 1. FNI has also included the effective FIRM for your reference.
FNI has concluded that the recent studies in conjunction with current topography best represent the
existing 1 OO-year floodplain. The City protests the approval ofthis DFIRM and respectively requests a
meeting with a FEMA representative at the earliest convenience to discuss updates and concerns with the
new DFIRM. Please contact Mike Wayts to schedule a meeting at 214-217-2222.
Sincerely,
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Attachments
cc: Keith Marvin, P.E. - City ofCoppell
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Zone A Floodplain
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