Shadowridge P4/FP-CS 890803GINN, INC.
CONSULTING ENGINEERS
August 3, 1989
Mr. Russell Doyle, P.E.
City of Coppell
P.O. Box 478
Coppell, TX 75019
Re:
Shadow Woods Estates
Construction Plans Review
Dear Mr. Doyle:
We have reviewed the above referenced project for conformance to
City standards and offer the following comments:
Provisions for future extension of Freeport Parkway (M6D)
110' right-of-way, in the vicinity of Lot #13, Block A,
needs to be addressed.
The required escrow for construction of Coppell Road should
be addressed if it has not already.
If not already done, the floodplain study needs to be
reviewed by th City's Floodplain Administrator.
Provide "note" or some means to indicate that no structures
or fences of any kind will be allowed to be built within the
floodway on Lots 13-24, Block A.
The sight easements along Coppell Road should be 45'x45' as
per ordinance, not 35'x35' as shown.
The variance to allow maximum street grades of 8% should not
be allowed. Subdivision ordinance allows 5% maximum.
®
Suggest additional "DRAINAGE EASEMENTS" be provided on creek
Lots 13-23, Block A, not just where storm pipe occurs.
For the streets connecting to Coppell Road, minimum curb
radius shall be 25' minimum, not 20' as shown.
Provide information as to base material under asphalt
transitions.
10.
Show future 45' pavement on Coppell ROad and connections to
Halifax, Greenwich and Edinburgh Lanes.
17103'Preston Road · Suite 100 · LB 118 · Dallas, Texas 75248 · Phone 214/248-4900
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
In the past, City has had problems (fire, address, etc.)
when two streets change names in cul-de-sac, such as
Edinburgh and Halifax. Please address.
On profile sheets, grades of 7.5%, 8.0%, 6.9% and 6% for
streets or alleys are too steep. These should be addressed.
The steep street/alley steep slopes are conducive to
allowing storm water to flow past inlets, thereby rendering
them useless. The storm water flows usually end up in sump
area where inlets are located, where they quickly exceed the
inlet capacity thereby causing flooding situations.
Provisions for positive overflow, should a situation such as
this occur, should be maintained at all times.
After viewing similar drainage conditions in other parts of
the City, in our opinion the inlets and storm sewer system
in the area of Edinburgh and Greenwich will be adequate
enough to handle only the minor storms that occur. Storms
of greater duration or larger flows will greatly burden the
system.
Have engineer provide information as to disposition of
offsite drainage south of alley of Block A, Lots 5 through
11.
The requested variance of the open ditch along Coppell Road
should be addressed as to maintenance, provisions for future
improvements, and construction to City standards. Provide a
section of proposed ditch. Take into account future 45'
wide pavement edge, side slopes, concrete ditch bottom, and
larger radii from three streets connecting to Coppell Road.
Address high velocities and potential erosion problems on
ditch along Coppell Road.
Provide detail of concrete rip-rap, north of Edinburg Lane.
Note on storm sewer plan indicates "contractor shall provide
diversion channel, if necessary, during construction". We
suggest that any alteration to the existing Cottonwood
Branch floodway should be addressed through the proper
channels prior to allowing contractor to beg~n construction.
What provisions are made to prevent erosion at headwalls
along Cottonwood Branch?
On alley "C" and Greenwich Lane, the inlets at the end of
steep slopes, and in addition to the way alleys and gutters
are constructed, will only intercept a very minor amount of
stormwater.
Line A-1 ~a~.~i~ Lat. A-t.a~e~qessive in slope.
23.
On Line "B" storm sewer plan/profile, the relation of the
proposed finished floor elevation and the curb elevation
lends itself to contributing to potential flooding
situations. This should be addressed.
24.
We would strongly urge that no curves in sanitary sewer
lines be allowed.
25.
Are any provisions being made to bring top of manhole (Line
"A") to be raised above 100-yr flood elevation?
26.
On the grading plan, there are discrepancies with the
finished floor elevations indicated.
27.
The railroad tie walls must not infringe on the floodway
limits. Additionally it may have to be designed by a
structural engineer and approved by the building inspection
department. Provide a detail on the "slope" from the
floodway limits, as shown on the grading plan.
28. Provide side slopes indication on "swale" sections.
29.
Coordinate any comments or suggestions by M.U.D. No. 1
District Engineer. Please have tM engineer return the
"marked-up"set of plans whenever they address the above
items.
Should you have any questions, please contact us.
Sincerely,
Gabe Favre
GF/dsp
cc: Benjamin dela Cruz
Mike Daniels, P.E.
Taryon Bowman
H. Wayne Ginn, P.E.
~ John C. Karlsruher, P.E.
'!~'~"i~'~' 89305