Alford Media-CS 970805 214654012~
ee/e5/1997 eg:5i 214654eC SPIARS AND DEO~ PAGE
To: Mike M~rtin, P.E.
IRe: Flood PI.in Revi.iona
Date 8/05/97
Fax #: (972) 304 -3570
Pages: I
DUNAWAY ASSOCIATES, INC.
ENGINEERS · PLANNERS
LAND,~:APE ARCHITECTS * SURVEYORS
DALLAS · FORT WORTH
FAX MEMORANDUM
~-.--I~m writing in response to your co~ drive. being in the floodplain on our
Preliminary Plat submittal for the~roject.
The 1(30 yr. floodplain reaches to the top of the existing culverts. The existing roadway
is not in the floodplain. We will widen the roadway and lengthen the culverts, but this
will have no impact on the floodplain for Cottonwood Branch.
The floodplain area mentioned is where Cottonwood Branch backs up into a small ditch
and is not part of the c~eek's conveyance area. Since the backwater models developed
for creeks such as this do not recognize "backup areas" it is not possible to study or
determine the impacts of such changes made to them.
We feet that the only engineering information pertinent to this ditch would relate to the
adequacy of the proposed culverts to handle water in the ditch coming from the south.
We will be prepareing a drinage area map to size these culverts in the final design.
If you have any questions, feel free to call me or we will discuss this at the DRC
meeting on Thursday.
Thanks.
From tyre desk of ..,
Paul Lee, P.E.
2351 W. Northwest Hwy., Suite 3280
Dallas, Texas 75220
(2f4)-e54-0123