Parks Coppell FS-CS 860212 HAWRYLAK & ASSOCIATES, INC.
P.O. BOX 13574 AI:IL.I~GTON, TEXAS 76013 (817)467-07
February 12, !786
Cty of Coppeil
P.O. Box 478
Coppeil, Texas 75019
Attn.: Hr. Ed Powell
Ref.: Cottonwood Branch Channel Improvements
Dear Hr. Po;,~ell,
~e have reviewed the letter sent from us by Ginn Inc. and would
i Ke to address the items mentioned over the Cottonwood Branch
Channe! Improvenments in the Northport Business ParK.
i. As mentioned to Ginn inc., it is our understanding that the
city would accept maintainance of the channel after con-
struction. That is the reason for acceptance anO inspection
by the city. if it is to be maintained by the owner, our
clients feels that their should be no inspection fee. ih
addition to this, the client has spent a large sum of money
for slope protection and soil erosion protection to insure a
quality earth channel ,.vith a minimum of ma ntenance.
~. As per our meeting with G~nn !nc., we were re!uctanct to
p~o,ide. ~ a drainage area mad mainly,., because of the ~ize_ of
the drainage water shed (approximatiy 2,000 acres), in ad-
dition to this, a copy of this map ~as provided in the
report by Caffey & Horrison.
3.a.Since it is required by F.E.H.A. that the velocities remain
within a specified level (dependant on the exisiting soil
conditions) which and within ~ 0.001 of a foot, we fee safe
in assuring you that the building of this channel will not
create an erosion problem either up or downstream. See item
D, page !? of report for additional commen s.
b. See item a. above and item C-8, page !8 of report.
c.The channel is designed to contain the entire ultimate and
existing designs within the banks of the channel. Th~s
means that both the flood plain and flood way of the channel
w~!! be contained for a !007 flood. These changes wil be
made by F.E.H.A. after construction and submission of~-s
builts plans. See ~tems = page !3 and C-& pane 18. of
· . . ~, . , . _
report for additional comments to this item.
d.The ex sting area inwhich we are proposing construction is a
creek channel and will still be as such when we are finish
with little or no impact on the enviroment.
City of Coppeli
Page 2
e.We will provide you with approval by Grapevine as soon as we
recieve it. They in turn would like the same letter from
YOU,
4. Our plans wi!! be change to shot~ the 6" thick channel as
requested.
5. As mentioned above, our channel is designed to carry both
the existing and ultimate design totally within the banks of
the channell. Since the channel ~vas designed for business
and industial sites upstream, we are confident that there
will be no additional water at any time. We have have how-
ever, an average of 4-4.5 feet of freeboarO above the
existing waterline.
We will send be sending you and Ginn !nc. an updated set o~
plans showing primarely the F.E.M.A. stations and O's for both ulti-
mate and existing flows.
i hope we have addressed any questions you m;ght have had. i
you have any other questions, or if we can be of any further assis-
tance to you, please fee! free to call.
Sincerely,
Steve Mason
Project Engineer
cc: Ginn !nc.