FS8601-CS 860417GINN, INC.
CONSULTING ENGINEERS
April 17, 1986
J. E. Powell, P.E.
City Engineer, City of Coppell
Post Office Box 478
Coppell, Texas 75019
Re: Denton Creek Floodplain Study
Coppell, Texas
Dear Mr. Powell:
The purpose of this letter is to provide you with a summary of
the meeting held on Friday, April 11, 1986, at 2:00 PM in our
offices concerning the above mentioned study. Mr. Phil Deaton,
P.E., of Dannenbaum Engineering representing Lomas & Nettleton,
attended the meeting with myself and Mr. Carl Anderson, P.E.,
representing the City of Coppell. We discussed the impact of
the Denton County Levee Improvement District NO. 1 Channel
Improvements on the natural channel of Denton Creek in Coppell.
On behalf of the City of Coppell, Mr. Anderson and myself
voiced concern that construction of the channel improvements
in conformance with the information we currently have could
lead to irreversible environmental damage to the natural creek.
Mr. Deaton informed us that Dannenbaum Engineering has revised
the channel bottom elevations and is currently monitoring and
recording the water surface elevations daily at various points
in the natural creek channel. The water surface elevation data
can be correlated to the recorded flows at the USGS stream
gaging station at Highway 121 to establish the average low
flows over a short period of time. Dannenbaum will provide the
above stream flow data gathered to date as well as the current
revised and "as-built" channel information to Mr. Anderson as
soon as possible. Mr. Anderson will review and analyze the new
data and revise the HEC-2 computer model to reflect the current
data and include any changes in his findings in the final draft
of the subject study.
Mr. Anderson will also review the above mentioned current channel
data to determine the effect of the channel improvements on low
flows in the natural creek channel. If the new data indicates
that the proposed channel improvements will not allow the natural
creek channel to maintain enough minimum flow, in Mr. Anderson's
opinion, to preserve the natural environment, we intend to meet
with Dannenbaum Engineering again and request that the Denton
County Levee Improvement District No. 1 install some diversion
dikes to maintain the minimum required flow (as per Mr. Anderson)
in the natural creek channel.
16135 Preston Road · Suite 106 · Dallas, Texas 75248 · Phone 214/386-6611
J. E. Powell, P.E.
April 17, 1986
Page 2
Mr. Deaton did point out during our meeting that the proposed
Levee District Channel is designed to flow water continuously
This will be taken into account in further discussions and
investigations.
As mentioned above, Mr. Anderson will hold up printing the
Final Edition of the Denton Creek Floodplain Study until he
receives reviews and evaluates the new revised and "as-built"
channel information.
If you have any questions concerning the above, please call me.
Sincerely,
John C. Karlsruher, P.E.
/jc
cc:
Carl V. Anderson, P.E.
Phil Deaton, P.E.
H. Wayne Ginn, P.E.