Parkwood P1/FP-CS 830601I IOGAN & RASOR, ,nc.
Engineers · Planners - Consultants
June 1, 1983
Honorable Mayor and City Council
City of Coppell
616 S. Coppell Road
P.O. Box 478
Coppell, Texas 75019
Re: Subdivision Review Parkwood Section One
Coppell, Texas
Gentlemen and Mrs. Thompson:
As per the request of Mr. Scott Barnett, we have completed our review
of the above referenced subdivision to determine its compliance with
the existing Subdivision Ordinance, the requirements of the Texas
Department of Health, and do hereby offer the following:
The Preliminary Plat for the above referenced subdivision was neither
reviewed nor approved by this office.
Final Plat
1. Contours with intervals of 2 feet or less, need to be shown
on plat.
2. Engineers seal needs to be put on plat.
3. Location, type of material and approximate size of all
monuments need to be indicated on plat.
4. Designation of the proposed uses of land within the sub-
division needs to be indicated on plat.
Paving
A. Plate No. 2
1. The angle of centerline of street intersections needs
to be shown on the plan.
2. The curb return radius at all street and alley inter-
sections need to be shown on the plan.
3. Barrier free ramps shall be provided at all street and
alley intersections.
4. Concrete sidewalks having a width of not less than
four (4) feet and a thickness of not less than four (4)
inches shall be constructed of 2000 P.S.I. concrete on
both sides of all streets one (1) foot from the property
line and within the street right-of-way.
Suite 800 One (~alleria Tower
13355 Noel Road 214/392-4600 Dallas, Texaa 75240
Draina9e
A.
5. Show flow arrows on plan to indicate direction of
storm water flow.
B. Plate NoS. 3 and 4
1. Same as comments 1, 2, 3, 4 and 5 for Plate No. 2.
2. Provide 130 feet verticle curve at station 2+00.
Plate No. 4.
C. Plate No. 5
Same as comments 1, 2, 3, 4 and 5 for Plate No. 2.
Provide 140 foot verticle curve at station 3+00 Parr
Street and 120 foot verticle curve at station 3+00 Coats
Street.
D. Plate No. 6
1. Same as comments 1, 2, 3, 4 and 5 for Plate No. 2.
2. Provide 150 foot verticle curve at station 6+56.30.
E. Plate No. 7
Same as comments 1, 2, 3, 4. and 5 for Plate No. 2.
F. Plate No. 8
The angle of centerline of alley intersections need to be
shown on the plan.
The proposed centerline of alley grade between station
2+50 and 13+77.44 needs to be raised 6 inches in order to
match proposed invert of alley with proposed top of curb
on Willingham Drive.
G. Plate Nos. 9 and 10
Same as comment I and 2 for Plate No. 8.
H. Plate Nos. 11 and 12
1. Same as comment I for Plate No. 8.
2. Provide 100 foot verticle curve at centerline station
10+00 Plate No. 11.
3. Provide north arrow on plan part, ~late No. 11.
Plate No. 13
1. Need to show on drainage area map limits of drainage area
contributing run-off into subdivision.
2
2. Need to show arrows for direction of storm water flow.
3. The storm water carrying capacity of Alley's in Blocks
No. 1, 3, 4, 5 and 6 is exceeded. Provide storm sewer
system, or add curbs to increase carrying capacity of
alleys.
4. The drainage area map should be revised along alley in
Block No. 7 to correspond to proposed alley grades as
shown on Plate No. 12.
5. The storm water carrying capacity of Harwell Street at
Parr Street is exceeded. Extend storm sewer system
south to Parr Street.
6. A complete review of drainage area map can not be
accomplished until a solution to the storm water in the
alleys can be achieved. Once this is done, the amount
of storm water flowing into the proposed streets can
then be determined and the location of inlets placed
accordingly.
B. Plate No. 14
1. Hydraulic gradient line and elevations need to be shown
on profile, keeping in mind that hydraulic gradient
line must be at least 1.5 feet below proposed gutter
line.
2. Proposed storm sewer system in Harwell Street needs to
be extended to Parr Street.
C. Plate No. 15
1. Same as com~nent i for Plate No. 14.
2. Proposed drainage channel needs to be shown on plan.
D. Plate No. 16
1. Plan profile of proposed earth channel is incomplete.
Provide additional information.
2. The proposed earth channel slope of 0.10% grade is too
flat for an earth channel. Try at least a 0.30% slope
if possible.
3. Channel improvements beyond the limits of proposed sub-
division need to be shown on plan and profile. Also,
drainage easements need to be provided.
4. Storm drainage right-of-way and easements for proposed
earth channel shall have sufficient width to provide
for excavation of the open channel or proper width,
plus ten (10) feet on each side to permit ingress and
egress for maintenance.
Water and Sewer
A. Plate No. 17
1. The location of the proposed water and sanitary sewer main
in relation to either the centerline of street or right-of-
way needs to be indicated on the plan.
2. The fire hydrant coverage for lots 3, 4 and 20 in Block 7
appears to be inadequate. This needs to be checked to
insure required coverage.
3. The manhole spacing for Line "H" is too far apart. Pro-
vide additional manhole at approximate centerline station
3+65.
4. Additional water valves need to be provided as indicated
in red on the plan.
B. Plates No. 18 and 19
1. At all sanitary sewer manhold locations, provide a minimum
of 0.10 feet difference in flow line elevation between
the incoming pipe and the outgoing pipe.
2. Line "D" sanitary sewer main is too Shallow. Subdivision
regulations require a minimum of 5 to 6.5 feet deep to
invert.
Others
1. Plans do not include details for paving, storm sewer,
water or sanitary sewer improvements. These details
need to be a part of the plans.
2. The plan profile sheets for the paving improvements need
to show all the proposed or existing improvements on the
plan. Such as, water, sanitary sewer, and storm sewer
improvements.
3. Other comments have been noted on the plans.
We appreciate the opportunity to assist the City in this matter and
please advise us if we can assist you further.
Very truly yours,
HOGAN & RASOR, INC.
Eduardo H. Pe~a
4