ST8402-CS 880819Jerry Parche' Consulting Engineers fi~Ill ~ .... ~'~ ~'
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Arlington, Texas 76016 __~..~...~Z~/.
Re. Requested Water Services and M~~~~~h~/ ~or ABQ
Development; Denton Tap Road Improvements fro~andy Lake
Rd. to Denton Creek, Coppell, Texas
Dear Mr. Parche':
As per our telephone conversation\of Thursday, August 18, 1988,
concerning the above, we are respohding to your letter of July 8,
1988. We have reviewed your request on behalf of ABQ Development
for three 8" water services from the existing 16" water main
located along the east side of Denton Tap Road, across from the
ABQ property; as well as the extension of the same 16" water main
west across Denton Tap Road along the north side of Parkway Blvd.
We have prepared drawings showing the abovementioned 8" water
services and 16" water main extension, and their impact on the
proposed Denton Tap Road Improvements which are currently under
construction. These drawings are attached for your use.
In light of the abovementioned review, it appears to be feasible
and necessary to construct the 16" water main extension as a part
of the Denton Tap Road Improvements as Change Order No. 1,
providing that the City Council of the City of Coppell approves
this action. It appears that this extension can be accomplished
at the expense of the City of Coppell,.now, with reimbursement of
part of the cost by ABQ in accordance with the attached excerpt
from the Subdivision Ordinance at the time of platting of the
first of their properties which will be served by the water main.
Also, as discussed yesterday, the future developments which occur
to the west along Parkway Blvd. will be able to tie their on site
water mains to the 16" water main as it is extended to the west.
The 16" water line in Denton Tap is planned to extend north from
Parkway as shown on the plans you viewed at Jack R. Davis
Consulting Engineers. We expect that Magnolia Properties may be
required to extend the 16" water line north from Parkway,
crossing Denton Creek to serve their future developments. The
one ABQ tract north of Parkway Blvd. adjacent to and west of
Denton Tap Road may have to be served from this northward
extension of the 16" water line in which case some prorata cost
would have to be paid by ABQ. If, by chance, ABQ should develop
first, they may be required to extend the 16" water line north as
far as their northern property line, which will make them
eligible to recover a reimbursement for the additional cost over
17103 Preston Road · Suite 100 · I,B 118 · l)allas, Tcxas 75248 · I'hone 214/248-4900
first, they may be required to extend the 16" water line north as
far as their northern property line, which will make them
eligible to recover a reimbursement for the additional cost over
and above a 10" line for the oversize main. The oversize
reimbursement will be in accordance with the attached excerpt
from the Subdivision Ordinance.
The 8" water services requested at Denton Tap Road Improvements
Project Stations 182+30, 186+70, and 195+00 have been evaluated
as shown on the attached sketches. As you can see, the proposed
8" services will be under the proposed new pavement for most of
their length, as well as being relatively deep where they cross
under the proposed storm sewer box culverts. In addition to
aforementioned, these services will have to cross the Dallas
Water Utilities 30" water transmission line to Flower Mound. In
summary, these services will be comprised of an unusual number of
fittings and may be difficult to maintain. Of course, none of
the foregoing is obvious until one actually gets into the design
of the services.
We have prepared Exhibits "A", "B" and "C" in anticipation of
proposed Change Order No. 2 to the Denton Tap Road Improvements
project if the City of Coppell chooses to instruct us to
accomplish the work shown thereon. However, since we have had
the opportunity to prepare the attached sketches, we do not think
that it is appropriate to pursue constructing the services, but
recommend instead that a future 8" water main be constructed by
developers in a~10 foot utility easement west of and immediately
adjacent to the west Right-Of-Way line of Denton Tap Road
connecting to the proposed 16" water main extension in Parkway
Blvd. and the proposed 12" water main proposed in Mills Lane,
which is already included in this project. The reasons for this
recommendation are:
An 8" water main along the front of the properties on
the west side of Denton Tap would provide a looped
system providing more flexibility for future service
connections, and better reliability with lower
maintenance requirements than the three individual
services mentioned above; and
e
In the event of a leak sections of the looped parallel
main will be readily accessible to isolate and repair,
providing flow from two directions, whereas the services
extended across Denton Tap Road would be difficult to
repair and isolation of the line with the leak may
totally cut off water service to a future development;
and
Repair of a leak in one of the water services proposed
by ABQ may entail closing traffic lanes and removing the
proposed new 8" concrete pavement surface of Denton Tap
Road. The possibility of having to close traffic lanes
or remove pavement for repairs is minimized by
constructing a parallel water main on the west side of
Denton Tap Road.
We are transmitting both proposed Change Order No. 1 and No. 2 to
L. H. Lacy for pricing and will be happy to notify you and the
City of Coppell when we have received their response. The City
of Coppell will make the decision of whether or not either or
both Change Order proposals will be accepted. We thank you for
your patience in this matter. Please call me if you have
questions.
Sincerely,
Karlsruher, P. E.
cc:
H. Wayne Ginn, P.E.
Alan D. Ratliff, City Manager
Russell Doyle (w/attachments)
Steve Goram (w/attachments)