FIRM-890726Kimley -Horn and Associates, Inc. 12660 Coit Road, Suite 200, Dallas, Texas 75251 . (214) 386 -7007
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July 26, 1989 West Palm Beach, Tampa, Orlando, Ft. Lauderdale, Vero Beach, Ft. Myers, Stuart
Mr. Russel Doyle, P.E.
City Engineer
City of Coppell
P. O. Box 478
Coppell, Texas 75019
Re: FEMA Response to the City Review of the FEMA Restudy of the City of
Coppell Flood Insurance Study
Dear Mr. Doyle:
We have recieved a copy of the FEMA
Flood Insurance Study for the City.
follows:
response to our review of their revised
FEMA wants four additional items as
1. FEMA asked that we provide information
floodplain. These floodplains were not
because it was our understanding that FEMA
determination concept. This is the only
return frequencies would be required.
for the 10 and 50 -year
determined in our study
was abandoning the zone
reason that these extra
2. FEMA pointed out that our study did not include all of the Moore Road
Bridge cross sections developed in the study for the Moore Road
Bridge revision. This was an oversight on our part, and will be
corrected.
3. In determining the starting conditions for Grapevine and Denton Creek
we used a conservative approach that would produce higher flood
elevations. Our approach assumed that the peak discharge for Denton
and Grapevine Creek would occur coincidentally. FEMA suggests
that another approach would be more appropriate. They suggest the
use of the slope area method to determine starting conditions.
4. FEMA requires that we resolve the study differences between our study
and that prepared by Jerry Parche' for Parkway Blvd.
Building client relationships since 1967
EiiiL�or�
Coppell
Page -TWO-
We are considering each of these comments by FEMA and will discuss them
with you when we have had a chance to assess their impact. We will provide
you with the results of our analysis next week.
If we can provide further information please call me.
Sincerely,
KIMLEY -HORN AND ASSOCIATES, INC.
Ronald W. Morrison, P.E.
Senior Hydrologist