Cambridge Phase 1-CS 930913 Kimley-Horn and Associates, Inc.
ENGI~JEER lk.G. PLANN NG..~ND r-NV RONr. IENTAL COIqSLILTAN-S
:2660 CO,t Road Su;'.e 300 DaiSes. Texas 75251 214-386-7007 Fax 2;4-239-3820
September 13, 1993
Mr. Kenneth M. Griffin, P.E. ~~~O? .,,~
City of Coppell
255 Parkway Boulevard ~' __L,~
Coppell, Texas 75019
Re: Floodplain review for property adjacent to Denton Creek
and north of DeForest Road
Dear Ken:
Belo~re our review comments for the hydraulic models on the subject floodplain reclamation. Appendix A. The FEMA forms should be included.
As an overall comment, the holes punched in the computer runs eliminated some of the numbers.
The storage runs in the report do not correctly define volume storage. Ineffective flow cards (X3) were
used to block out ineffective flow, they also block out storage which is actually there. Consideration
should be given to the use of X5 cards and removing the X3 cards.
The roughness values (NC) for the added cross sections were generally higher than previous cross
sections for the existing condition. This must be justified since it has a direct effect on elevations and
storage.
/.~ The added cross sections were only plotted for the proposed condition, please plot in the existine
condition as well.
.~ Please supply the field survey data for the additional cross sections.
/..~TY. ..... This hydraulic modelling must be done in accordance with the City of Coppell Ordinance and the
Corridor Development Certificate (CDC) process. Please address the CDC process in the text of your
next report.
Please revise the attached report and re-submit for review. If there are any questions, please contact me.
VeD: truly yours,
KIMLEY-HORN AND ASSOCIATES, INC.
~iore. P.E., RPLS
Civil Division Manager
Attachment
Gharlolte . Da las ~ Fort Lauderdale ., Fort Myers · Las Vegas . Orange . Orlando
P~oep.x . Ra'eigh * Sarasota · Stuart · Taml~a · Veto Beach · V.rgmia Beach., West Palm Beach
Build ~' g client r eiati o n sl~i D s s~q c e 1967
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