ST9401-CS 950804Morrison Hydrology/Engineering, Inc.
210 Arnold * Arlington, Texas 76010 · Metro (817) 461-0321
August 4, 1995
Mr. Ulys Lane, P.E.
Weir and Associates, Inc.
4300 Beltway Place
Suite 130
Arlington, Texas 76018
Rex Denton Tap Road, coppell, Texas
W & A No. 94093
Dear Mr. Lanes
This is an update on our progress with the subject bridge analysis and a
completion schedule.
As you are aware, the major time delay for this study has been because we
have not been able to obtain a copy of the Effective Flood Insurance Study
(FIe) model. The models provided by the City were not correct, and we were
unable to obtain the effective models from Dowdy Anderson.
We finally received the effective FIS model from FEMA last month in hard copy
format. We had to code this model into our computers and obtain a duplication.
This is now complete.
Kimley Horn and Associates developed an Ultimate condition model for the City.
We intend to use this model to obtain ultimate condition flows. These
ultimate flows will be input into the FEMA FIS model, and this will be our
design condition.
The following Is our schedule for completion of the bridge studyl
Schedule
~otion
Add survey data to
the FEMA FIS model to
obtain an existing condition
model.
Complettg~ Date
Aug. 9, 1995
O~AH NOSI~OW ~:~0 gI, II dBS
~! I 1[
Page -2-
2. Review the ultimate Aug. 9, 1995
condition HEC1 model
completed by Kimley Horn
and input results in the
existing condition HEC2
model to obtain an uZtimate
condition HEC2 model.
3. Input the proposed bridge Aug. 11, 1995
changes into the existing
condition model to determine
a proposed condition.
4. Modify the proposed condition Aug. 17, 1995
as necessary to obtain a
model that causes no increase in flood
levels at FEHA and ultimate conditions.
5. Develop existing and Aug 22, 1995
proposed condition Zloodways.
6. Print models Aug. 23, 1995
Plot water surface profiles
Plot cross sections and cross
section modifications
Delineate existing floodplain
and floodway
Delineate proposed floodplain
and floodway
7. Prepare a report that describes Aug. 29, 1995
methodology and results and provides
necessary documentation
This means that you will have information to design the bridge by no later
than Aug. 17, 1995.
Please let me know if this poses a problem. In the meantime we will try to
improve this schedule if possible.
Sincerely,
Morrison Hydrology/~ngineering, Inc.
Ronald W. Horrison, P.E.
Senior Hydrologist