Coppell Cross L2-CS 990322Date:
FroI11:
To;
Proje~-t:
23:18
2i46540122
DUNAWAY ASSOC~ES
PAGE 82
3/22t99
Chris Lam
Micl~ael Martin, P.E.-Cily of Coppell
Coppe~l Crosmng 98566
Du away ssoc at s, Inc,
Engineers ' Planrmm · Landscape
ArChitects * Surveyors
Dallas, TX · Fo~t Wortfl · Roanoke, TX
MEMORANDUM
SUBJECT: Storm Drainage System
The purpose of this memo is to provide the drainage information per your requested; based on
our conversation on March 18, 1999, Our calculation for the eXisting (2)~36" RCP pipes show
that those pipes are under sized and does not have the capacity to handle, the amount of
discharge from the Hollows {~ Northlake Woodlands development. The calculations indicate
that we would have a surcharge above the top of our inlets. Our plans reflect part of the
surcharge applied to the existing storm drain system.
As we have discussed before, the detention area in the Dallas, Ught and Power Easement
would provide relief of the discharge into the (2)-36" RCP pipes and it is our understanding' that
Tipton Engineering inc. will calculate the detention system.
If you have. any questions or comments regarding the above memo, please contact, our office
at (214) 654-0123.
Thanks
., ·
Chris Lam
CC: File
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' ' ' ....... '" " '(21 0123 x FA~'(214).654-0122
2351 tV.. Northwest Hwy., Suite 3280 ~ De#as, Texas 75220 ~
1501 Merrfmec, Suite 100 ~ Fo~t Worth, Texas 76107 ~ (817).335.ff2f x FAX(BlT),.335-7437
215N. Oak Stni~, Suite B ). Roalx~e, TeXas 7~262 x (817)-491-0~2g ~, FAX (Sf7)..491-0640