FS9903-CS 950222Morrison Hydrology/Engineering, Inc.
520 Avenue H East · Suite 102 · Arlington, Texas 76011 · Metro (817) 640-4554
February 22,1995 ~ [ ~
Mr. Ken Griffin, P.E.
Assistant City Manager/City Engineer
P.O. Box 478
Coppell, Texas 75019
RE:
Fill Study/Northwest Corner of Riverchase at MacArthur Blvd., south of
Shady Lake Road
Dear Mr. Griffin:
Mr. Dayton Macatee of Macatee Engineering provided us with a copy of your
courtesy review (copy attached). After discussing it with him we suggest a
possible cure for your consideration. The problem with the proposed channel
is that a grasslined channel would not drain fast enough to prevent standing
water. We could take advantage of this by deepening the channel and creating a
permanent pool along the channel. If the pool could be maintained at
approximately five feet deep this could provide an aesthetic ammenity to the
area. In addition, this would address the standing water problem.
Regarding the flood level increase mentioned in your review, this increase was
only 0.02 feet or about one quarter inch. We felt this increase was
insignificant. However, with a pond as the channel bottom the roughness value
would be lowered sufficiently enough to eliminate this slight "increase".
We have not modified the report to use the pond concept because we want your
input first. Please let us know your thoughts. We will contact you by phone to
follow up.
Sincerely,
senior Hydrologist
1'4t~CQ[EE ENGINEERING, IN~., T.EL No. 21d 575 1~0 Feb 16,95 10:50 P,O1
The City With A Beautiful Future
P.O. Box 4?8
Coppall, Texas 75019
214-482-0022
January 2:3, 1995
Dayton Macate~
Macatee Engineering, Inc.
P.O. Box 12617
Dallas, TX 75225
Re: Fill Study/northwest corner of Riverchase at MacArthur Bivd., south of Sandy Lake Road
Dear Mr. Macatee:
In late 1994, a study was processed to the City of Copyell regarding fill and the construction of
a channel along property generally located. south of Sandy Lake and east of MacArthur Bivd.
Your submittal letter indicated that you 'were WOrking 'on. a "m~ss grading plan" and that it
would be submitted in a week or two. A's 6f/his dat~; the' City has not received any overall
grading plan for this proposed development. Obviously, that overall grading plan is critical in
determining the mount of fill to. be placed on thi.~ property along with other adjacent properties.
You may also recall that, w~ 'talked 'about the fact 'that this fill Operation would have to
transverse not only your provefly but property to the south to insure that the water has a place
to drain during flooding.
I have made a courtesy review of the study and note several areas of concern:
1. Your narrative of the study indicate that it will be a grass lined channel. Please note that
the City is curremly experiencing problems with grass lined channels within the City of
Coppelt and that problem could be even more !nagnlfied on this grass lined channel because
of the flatness of the slope. You are proposing a slope of 0.15%. The grass lined channel
on this slope will experience standing and stagnant water, Therefore, when homes arc built
that back up to it those citizens will be calling the City to fix the problem. We currently
have an identical situation of a grass lined channel behind homes on the west side of town.
That particular channel has a slope twice as steep as this proposed channel and the City is
in the process of exvending almost $100,000 to fix the problem, That said, you should
propose some means of permanently improving this Channel. so that it is not a maintenance
problem for the City of Coppoll in .the ~tu~e, That c0uldbe either copcrete lined or some
other type of permanent improvement.
2, Another concern is in Table' 'l Of ~our comparison between eXiSting"~nd proposed 100 year
flood levels in which you' 'are showing a r!se in the water su~ace at Section 8. Please
HRCR]EE ENGINEERING, INC. TEL No. 214 3?5 1180 Feb 16,95 10:51 F.uZ
re, evaluate this section. The City does not allow any rise in the water surface.
The cross sections provided with the flood study show a substantial smoum to fill on the
adjacent TU property. Has contact been made with TU and are they in agreement with
fillinS on their property? it's safe to assume that if they do not allow the filling then you
will have a greater area to convey. However, if they do not allow the filling you also will
not have a side of your channel to construct, thereby reducing your ability to construct a
permanent improvement in this area. The amount of fill placed on th~ TU property could
also affect the height of the TU wires and whether or not they maintain proper clearance
from the ground. This issue should be explored with TU. If you are unable to fill on TU's
property and in some cases cut on TU's property, then you may need to reevaluate your
strategy in the reclamation of this property.
Along with this letter I am returning your check in the amount of $200.00 which was for
processing the permit t~ PEMA. The reason I am not processing the permit is because part of
the permit process specifies that the City has reviewed the study and found it to be in compliance
with our floodplain management regulations. For the reasons stated above I cannot support this
proposal at this time. As we have discussed in the past, on the surface the proposal appears to
have potential to meet our floodplain mtuirements, however, as currently subntir, ed and
proposed the City is not in a pos!tion to support it at this time.
If you should have any additional questions please contact me or if you would like to meat and
redlscnss this issue please contact me.
Sincerely,
,E.
Assistant City Manager/City Engineer
~le/ka~ffm/macatee.