FIRM-911218G�NGY M'�N
w
o o
Federal Emergency Management Agency
Washington, D.C. 20472
CERTIFIED MAIL
RETURN RECEIPT REQUESTED
The Honorable Mark Wolfe
Mayor of the City of Coppell
P.O. Box 478
Coppell, Texas 75019
DEC 18 1991
(100)
RE: Flood Insurance Study for the City of Coppell, Dallas and Denton Counties, TX
Dear Mayor Wolfe:
Please find enclosed two preliminary copies of the revised areas of the Flood
Insurance Study for the above referenced community. We have completed our
technical evaluation of the available data and have incorporated the appropriate -
changes into the enclosed copies. A description of the change with the
corresponding affected portion of the Flood Insurance Study is attached for your
information and review.
If you have any comments that might justify modifying our results, please use one
copy of the enclosed map(s) to identify the area of concern and return it to us
within 30 calendar days from the date of this letter. If you are in agreement
with our findings, please respond with a letter stating that you have reviewed
the accompanying material. If we do not receive any comments within 30 days, we
will continue processing.
In the near future, we will publish a notice of proposed Base (100 -year) Flood
Elevation (BFE) determinations in your local newspaper. This notice will
initiate a 90 -day period during which your community may submit appeals or
comments on the proposed BFEs reflected in the revised Flood Insurance Study for
your community. Following the 90 -day appeal period and the resolution of any
appeals, we will finalize the proposed BFEs and establish an effective date for
the revised study.
If you have any questions, please contact the Chief, Natural and Technological
Hazards Division of the Federal Emergency Management Agency in Denton, Texas
at (817) 898 -5127.
Sincerely,
William R. Locke
Chief, Risk Studies Division
Enclosures Federal Insurance Administration
cc: State Coordinating Agency ,�
Mr. Ronald W. Morrison, P.E., Senior Hydrologist I .3'
Mr. Ery A. Meyer, Nathan D. Maier Consulting Engineers, Inc.
Mr., William A. Anderson, P.E., Dan M. Dowdey & AssociaEe,s'
FEMA Regional Chief, Region VI '
Ms. M. Shohre Daneshmapd, Acting City Engineer -
Russell R. Doyle, P.E., City Engineer, Floodplain Administrator
City of Coppell, Dallas and Denton Counties, Texas
The Flood Insurance Study (FIS) and Flood Insurance Rate Map (FIRM) for the
City of Coppell have been revised to reflect updated hydrologic and hydraulic
analyses for Elm Fork of Trinity River and updated hydraulic analyses for
Grapevine Creek, Denton Creek, and Cottonwood Branch. These analyses were
prepared for the City of Coppell by Kimley -Horn and Associates, Inc., and
Morrison Hydrology /Engineering, Inc. Additional updated hydraulic analyses
for Denton Creek from the divergence of Old Denton Creek to Denton Tap Road
were prepared by Dan M. Dowdey & Associates, to reflect the completed Lake
Park Addition.
In addition, detailed flood hazard information was prepared for Tributary G -1
of Grapevine Creek. The hydrologic and hydraulic analyses for Tributary G -1
of Grapevine Creek were prepared by Goodwin and Marshall, Inc.
The following is a summary of the changes to the FIRM and FIS Report:
FIRM number 480170. panel 0010
The 100- and 500 -year floodplain boundaries, Base (100 -year) Flood Elevations
(BFEs), and the Federal Emergency Management Agency (FEMA)- designated floodway
for Elm Fork of Trinity River, Denton Creek, and Cottonwood Branch have been
modified for their entire length within the community, and Grapevine Creek has
been modified from its confluence with Elm Fork of Trinity River to approxi-
mately 125 feet upstream of Southwestern Boulevard. In addition, a FEMA-
designated floodway has been added for the Old Denton Creek channel just south
of the levee on Denton Creek. Corporate limits have been revised in the
northwest portion of the city to reflect recent deannexations.
For Tributary G -1 of Grapevine Creek, the 500 -year floodplain was changed to
100 -year floodplain, and BFEs and a FEMA- designated floodway were added from
the confluence with Grapevine Creek to approximately 0.6 mile upstream of
Bethel School Road. An approximate 100 -year (Zone A) floodplain has been
determined for the remaining portion of Tributary G -1 of Grapevine Creek.
FIS Report
The FIS Report, including Tables 1 and 2 (Summary of Discharges and Floodway
Data) and Flood Profiles 01P -05P, 07P -09P, and IIP -14P have been revised to
reflect the aforementioned updated flood hazard information. In addition,
flood profiles 06P and 10P have been added to reflect the new detailed flood
information for Tributary G -1 of Grapevine Creek and Old Denton Creek,
respectively.