ST9401WA-CS 960223MEMORANDUM
TO:
FROM:
DATE:
SUBJECT:
W&A NO.:
Ken Gdffin
Mike Martin
Ulys Lane
February 23, 1996
Denton Tap Road; Coppell, Texas
94093
Ron Morrison and I met with you yesterday to review the results of the Hydraulic studies
performed to confirm compliance with FEMA regulations. We also provided a study
based on more conservative assumptions for downstream conditions which resulted in
higher flood elevations downstream of Denton Tap Road. The proposed bddge
provided no rise in the upstsream 100 year FEMA and fully developed conditions with
the proposed bddge section. We reviewed the results of the studies and we
understand decisions were made as follows:
1. The bddge section as submitted which widens and increases section area at the
bridge location was desirable.
2. The low cord at the bridge was agreed to be set at elevation 463.
3. The elevations of the low points in the roadway north of the bridge was set at
elevation 462.3.
4. The drainage system discharging at the bridge will be routed to the downstream end
of the bridge. The tailwater to be used will be the ten year storm event since the steam
100 year storm is not coincidental to the drainage system 100 year storm. v
5. In the future when the sites west of the roadway and north of the creek are
constructed, the city will require a positive overT'low route through the development to
relieve the low points in the roadway in the event there is clogging of the system.
Please review the above and let us know if we misunderstood any decisions.
End of memo