Northlake WE P10B-CS 851031GINN, INC.
October 31, 1985
CONSULTING ENGINEERS
Don. A. Tipton, Inc.
6330 Belt Line Road, Suite C
Garland, TX 75043
Re: Northlake woodlands East - Phase 10
Final Plat
Gentlemen:
We have reviewed the above referenced project for conformance
to the City of Coppell Zoning Ordinance and Subdivision
Ordinance. Prior to placing on any agenda for approval, the
following items need to be addressed.
1. Street centerline alignment of Crane Circle and Crane
Drive, either side of Mockingbird Lane, is less than
125 feet. This is in conflict with the Subdivision
Ordinance. Please address.
A similar conflict Occurs with the centerline inter-
sections of Brant Circle and Mallard Drive.
2. The pavement shown on the plans, for the alleys, are not
in conformance with the City of Coppell standards.
Please address.
3. At Bethel School Road and Mockingbird Lane, the radius
should be 25', not 20' as shown.
4. A screening wall, in accordance with Zoning Ordinance
Section 32.1.7, shall be provided along MacArthur Boulevard.
5. Maximum allowable grade is 5%. Alleys No. 10 and NO. 11
have an 8% grade. Please address.
6. For I = 7.8 in/hr., Tc = 15 min., this reflects a 25 year
storm frequency based on TP-40; not a 100-year design
frequency as required by City of Coppell. For 100-year
design frequency and Tc = 15 min., I = 9.8 in/hr. Minimum
time of concentration should be 10 minutes, unless justi-
fied otherwise. In that case, I = 11.6 in/hr. Please
address.
Line "C" of storm drainage system, please provide cross
section of "grade to drain" ditch.
On Line "E" of storm sewer, with all the horizontal curves,
vertical breaks and pipe change sizes, is there any possi-
ble way this could be revised to provide for more "fluid"
design without interfering with other utilities?
16135 Preston Road · SuiTe 106 · Dallas, Texas 75248 · Phone 214/386-6611
Maximum spacing on sanitary sewer manholes shall be 500
feet. On Falcon Lane, Line "C-l" add a manhole as shown
on plans. Additional manholes as shown on plans shall be
provided. Provide manholes in lieu of cleanouts at ends
of lines greater than 200 feet from a manhole.
10. Minimum size sanitary sewer main shall be 8" diameter.
No 6" will be allowed by Subdivision Ordinance.
11. No horizontal curves in sanitary sewer are permitted.
This was addressed in our preliminary review comments.
12. Minimum water main size shall be 8" diameter, in accor-
dance with Subdivision Ordinance.
13. Sanitary sewer mains to be PVC, SDR 35.
14. Water mains to be PVC, Class 200, DR 14.
15. No jetting of backfill shall be allowed.
16. Embedment of backfill shall be as per minimum City
standards or better.
17. Maximum velocities or sanitary sewer lines is 10 f.p.s.
We will not recommend placing this on any agenda for approval
until the above items are addressed. If you feel we need to
discuss these items, please do not hesitate to contact us.
Sincerely,
Gabe Favre
/sr
cc: Vivyon Bowman
Steve Goram