ST9304-CS 870120REPLY TO
ATTI~NTION OF:
Planning Division
Mr. J. E. Powell, P.E.
City Engineer
City of Coppell
P. O. Box 478
Coppell, Texas 75019
DEPARTMENT Of THE ARMY
FORT WORTH DISTRICT, CORPS OF ENGINEERS
P. O. BOX 17300
FORT WORTH. TEXAS 76102-0300 January 20~ 1987
Dear Mr. Powell:
Thank you for your letter dated September 5, 1986 requesting a
review of the report, "Belt Line Road Analysi~ Elm Fork Trinity
River at Existing Belt Line Road Alignment" by Nathan D. Maier
Consulting Engineers, Inc.
Due to hydraulic complexities associated with the Belt Line Road
Bridge and funding limitations, a detailed review of the hydraulic
analyses presented in the subject report was not possible. A cursory
review of the results did reveal that velocities for the 100-year
frequency flood were 4.55 feet per second (fps), 8.01 fps and 6.83
fps for the left relief~ main channel and right relief Bridges at the
down stream side of Belt Line Road. This was for alternative 2 with
a 300, 260, and 300 feet long bridges for the left.relief, main
channel and right relief bridges. The velocities computed for the
main channel bridge could be slightly high.
It is our understanding that the proposed design currently being
prepared for Dallas County is recommending a 400 feet, 280 feet, and
320 feet long bridges for the left relief, main channel and right
relief bridges.
It is hoped that this information will satisfy your requirements.
Sincerely,
s C. Graham, P.E.
Chief, Flood Plain Management
Services Branch