Oakbend Addn-CS 921214December 14, 1992
Mr. Ken Griffin, P.E.
City Engineer
City of C~pell
255 Parkw~ay Boulevard
Coppell, Texas 75019
RE: Oakbend Pedestrian Bridge
Dear Ken:
As we discussed, I have re-mn the HEC-2 program for the tributary channel in Oakbend. The mn
now contains information conforming with the Albert H. Halff study. The following changes were made:
1)
2)
3)
4)
Starting water surface elevation revised to elevation 497.50
Q revised to 850 cfs (representing 100 year ultimate flow)
Old proposed box culvert removed from mn
Cross section at proposed bridge location added (section 4.1)
As you can see by the results, the water surface elevation in the area of the proposed bridge is at
about elevation 497.50. The bridge will allow the required amount of freeboard and will fully span the
channel. The evidence indicates that the bridge has no impact on the water surface elevation in this
channel. It is obvious that there is also no upstream impact on water surfaces as the box culvert at State
Road serves as a controlling point. We hope that you can approve this bridge quickly as we are under
a great amount of pressure by the homeowners in the subdivision to begin work.
If you have any further questions conceming this information, please call.
Sincerely,
CENTEX REAL ESTATE CORPORATION
Derek E. Earle, P.E.
Land Development Manager
Dallas North Division
Attachments
DEE/s
1660 S. Stemmons Frwy., Suite 150 / Lewisville, Texas 75067 / 214-221-5556