Stratford Manor-CS 960213 1 ~ Kimley-Horn
~'l ........... . Inc.
and Associates.
En~ineedng
Piann:ng
anO
Environmental
Consultants ·
S,~ite 300
~.2660 Co; Road
Dahas. Texas
75251
February 13, 1996
Mr. Kenneth M. Griffin, P.E.
Assistant City Manager / City Engineer
City, of Coppell
P. O. Box 478
Coppell, Texas 75019
Re: Floodplain Review for Estates of DeForest
Dear Mr. Griffin:
Attached is our review, performed by Ron Morrison, of thc Floodplain Study of
Denton Creek for Creekside Estates Development, located north of DeForest
Road at Lake Forest Drive.
Although this review was completed some time ago, I had interpreted your
message wrong about using Ron for this purpose. I apologize for this
misunderstanding and delay.
Very truly yours,
KIMLEY-HORN AND ASSOCIATES, INC.
Roy L. Wilshire, P.E.
Senior Vice President
jc
L :'..C I V I L',2-96'.GRIFFIN WPD
·
TEL 214 770 1300
FAX 2',4 239 3820
Morrison Hydrology/Engineering, Inc.
210 Arnold · Arlington, Texas 76010 o Metro (817) 461-0321
October 25, 1995
Mr. Roy Wllshire, P.E.
Klmley Horn and Associates, Inc.
12660 Colt Road
Suite 300
Dallas, Texas 75251
Ret Review of Floodplain Study of Denton Creek
Creekside Estates Development Project
Located North of Deforest Road at Lake
Forest Drive in the City of Coppell, Dallas
Denton Counties, Texas
Dated August 1995
by TIpton Engineering, Inc.
Dear Mr. Wilshire~
Having reviewed the subject report, we offer the following comments=
1. HEC2 Duplication of FEMA Existina 100 Year Floodway
It 18 assumed that this model is a duplication of the currently
effective FEMAmodel. However, comparison of the model results with the
FEMA Floodway Data Table found in the Flood Insurance Study (FIS) dated
April 15, 1994 (attached) shows that the models do not match. If this
model was obtained from another source approved by FEMA, it should be
cited so that the basis of the study model can be confirmed.
2. HEC2 Existino Condition Model
An existing condition model was not provided. It is assumed that the
report uses the "duplication models' as existing condition.
The following information is needed for the existing condition (or
duplication)~
a. Full plots of cross sections
b. Water Surface Profile plots
c. Existing Condition Floodplain and Floodway Delineation
Page -2-
HEC2. Proposed Condition Model
The basis of the proposed condition is that ineffective flow currently
exists beyond the channel banks, so whatever fill is completed has no
impact. This may or may not be true; however, it should be established
that this flo~ is ineffective. It could be split or divided flow. It
is not possible to determine from the information presented in this
report.
4~ Storaoe Reauirement s
There are no references to storage losses in this report, according to
the Corridor Development Certificate (CDC) Requirements.
5. FEMA Forms
The FEMA forms request is for a Letter of Map Revision (LOMR) and yet
the project is not built. This request must be for a Conditional Letter
of Map Revision (CLOMR).
We do not recommend approval pending more information.
Sincerely,
NO~tX~ON BX~I)ROZ,OG~'/~I'GXIEI~qXNG; XNC.
d W. Morrison, P. E.
Senior Hydrologist
FLOODING SOURCE FLOODWAY WATER 'SURFACE E~m"'~AT%ON~,~
Denton Creek
A 21,140~' 329 5,316 3.9 452.4 452.4 453.4 1.0
B 23,3701 325 * * 453.0 453.0 453.5 0.5
C 26,2201 571 3,677 5.8 456.7 454.7 455.1 0.4
D 29,280~ 1,136 8,383 2.5 45613 656.3 657.0 0.7
E 36,866~ 931 7,271 2.1 466.7 666.7 667.6 0.7 )
F 39,200~ 499 3,526 2.9 468.8 468.8 469.6 0.8
Old Denton Creek
A 1,100z 90 * * 453.0 453.0 A53.6 0.6
Cottonwood Branch
A 3.850~ 356 1,780 4.1 463,7 463.7 &64.5 0.8 ~
B 6,710z 587 2,554 2.9 470.1 470.1 471.1 1.0
C 11,335~ 270 2,156 3.1 487.4 487.4 488.1 0.7
D 14,705z 223 1,411 4..0 495.1 495.1 495.8 0.7
ZFeec above confluence with Elm Fork of Trinity River
zFeeC above confluence with Denton Creek
*Data ncc available
'-'1 FEDERAL EMERGENCY MANAGEMENT AGENCY
FLOODWAY DATA
m CITY OF COPPELL, TX
rn (DALLAS & DENTON COS.) DENTON CREEK - OLD DENTON CREEK - COTTONWOOD BRANCH
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