121 BP Phase 1-CS 810518Graham Associates, Inc.
CONSULTING ENGINEERS& PLANNERS
ARLINGTON 520 Avenue H East/76011/(817) 640-8535
DALLAS 17130 Dallas Parkway/75248/(214) 931-7141
FT. WORTH 6737 Brentwood Stair Rd./76112/{817) 654-2271
Ma.y 18, 1981
Mr. Jim Elium
City Manager
City of Coppell
Coppell, Texas
RE:
Jim:
Channelization of Cottonwood Branch
within Airport Business Park
This letter follows up my telephone conversation with you on May 12,
1981 and our previous Engineering Submittal of March 16, 1981. Our
client, Airport Business Park, wishes to make certain channel improve-
ments on their property located along the Cottonwood Branch of Denton
Creek. As detailed in our Engineering Data Submittal, March 16, 1981,
the channel will be an earthen section with a 30-foot bottom and 4 to
1 side slopes. The drainage area that is served by this section of the
branch is 2536 acres of land. Using the Coppell design criteria for
storm water analysis within a channel, the maximum lO0-year flow equals
6500 CFS. The proposed improved channel will provide for this volume
of water while maintaining a minimum of 2 feet of freeboard. The informa-
tion outlined above is provided as supplemental information to our
original submittal.
If you have any questions concerning this information please call us.
However, if this information and our clients' proposed improvememts to
the channel are acceptable by the City of Coppell, please indicate by
signing in the appropriate location below and return to us.
Sincerely, A~~VED:
Don Peebles, P.E.
/ ~ty Manager,'City'of Coppell, Texas
DP/sm