Oakbend Addn-CS 900918 Kimley, Horn i~!~ __
Kimley-Horn and Associates, Inc.
ENGINEERS · PLANNERS * SURVEYORS
12660 Coit Road, Suite 200 Dallas, Texas 75251 214 386-7007 Facsimile 214 2,'
September 18, 1990
Ms. Shohre Daneshmand
Engineer
City of Coppell
Post Office Box 478
Coppell, Texas 75019
Re:
Review of a Floodplain Determination
for Oakbend Addition along Cottonwood Creek in Coppell, Texas
Dear Ms. Daneshmand:
We have completed a review of the subject report, and offer the following comments:
The purpose of this report is to determine the location of the floodplain and
floodway by including extra cross sections from a previous study 'Shadow Woods
Estates.'
2. This study does not intend to reclaim any of the floodway or floodplain. The
intent is simply to establish it's location.
The computer run used in this study as existing condition is not the correct model.
The latest existing condition model as completed for the City of Coppell contains
information from the Shadow Woods Estates existing-condition cross-sections.
The result is that there are significant differences between the extended model
presented in this study and the current City model. It is fortunate that the model
used for this study resulted in higher flood elevations than those contained in the
City model; which means that the floodline shown is conservative.
4. The final plat accompanying the subject study incorrectly labels the floodplain
line as a floodway line.
The plat should show the minimum lowest floor elevation for each lot; which
should be the 100-year existing condition elevation plus two feet or the ultimate
condition 100-year elevation plus one foot, whichever is higher.
Anaheim * Charlotte · Dallas · Fort Lauderdale * Fort Myers * Nashville * Orlando · Phoenix
Raleigh * San Diego · Stuart * Tampa * Vero Beach * Virginia Beach · West Palm Beach
Building client relationships since 1967
C 9-90~CoplBend.rwm\9191.15
Ms. Shohre Daneshmand
2
September 18, 1990
Since the flood limits determined for the subject study are higher than those in the current
City study, and higher than those computed for the current Master Drainage Plan presently
under review, we have no problem with the layout of the subdivision as long as the correct
flood elevations are presented on the plat.
We do not recommend approval of this study or plat until the suggested corrections are made.
Please let me know if you need additional information or clarification regarding this
discussion.
Sincerely,
KIMLEY-HORN AND ASSOCIATES, INC.
Ronald W. Morrison, P.E.
Senior Hydrologist
pw
C 9-90~CoplBend.rwm\9191.15