Copperstone FS-CS 940602DOWDI:Y, ANDERSON AND ASSOCIA1 ~S, INC.
CIVIL ENGINEERS
16250 DALLAS PARK'VV^Y SUITE 100
DALLAS, TEXAS 75248
(214) 931-0694 FAX (214) 931-9538
June 2, 1994
Mr. Kenneth Griffin, P.E.
City Engineer
City of Coppell
255 Parkway Boulevard
Coppell, Texas 75019
Re:
Cottonwood Branch and Denton Creek
Flood Study
Dear Ken:
I appreciate your comments regarding the above referenced study.
The Manual used to analyze the creek was per HEC-2 Water Surface
Profiles, September 1990.
Your questions on page 4 of the report regarding the floodway using
encroachment Method 4 has been changed to reflect more clearly
which method was ultimately used.
Your question on page 5 of the report in "D. Floodway Analysis of
Denton Creek" regarding the increase of 0.01 ft. has been
corrected. The floodway elevation does not increase.
The typographical error on Table 2 has been corrected. At Section
34850, the Duplicate Effective Model, has been changed from 468.55
to 462.55.
On the application in Appendix A, the page 2 of 4, "Revision
Requested and Community Official Form". Our intent is to meet the
condition of the CLOMR with the exception that the previous Models,
Parche' had variations in cross-sectional data.
Mr. Ken Griffin, P.E.
Page 2
June 2, 1994
When Encroachment Method 4 was used the floodway limits would be
south of the improvements however, our intention is to only fill
the area denoted in Copperstone Addition. Our client desires to
reserve all remaining floodway capacity (conveyance) for the
Coppell Independent School District area, the property owner to the
south.
These are the issues that you wished to be explained.
any additional questions, please contact me.
If you have
Very truly yours,/~
William A. Anderson, P. E.
WAA; j rb