Vlgs of C P2/FP-CS 840813GINN, INC. CON.S tI.TING ENGINEERS
TO:
FROM:
DATE:
SUBJECT:
Mr. Mark Sweeney
Coppell, Texas
GINN, INC., City Engineer
August 13, 1984
Coppell Village
Drainage Ditch Improvements Only
We have reviewed the above referenced project for compliance with the City
of Coppell standards and offer the following comments.
Type "Y" inlet at STA. 1+52 is presently undersized for a 72"
diameter pipe connection. A minimum 9' x 9' outside wall
dimensions are recommended.
2. Show construction details for type "Y" and "S" inlets and also for
the Junction box.
3. Locate Junction box directly eastward from existing box culvert
and make tie-in. Keep grate inlet at low point and tie into system.
4. Base flows on Q50 not Q25 (Technical Paper #40).
5. Keep velocity in 18" diameter RCP Lateral 12.5 fps or less (if
possible).
6. New Property ditch line - add note - "grade to drain," showing flow
arrows.
If you have any questions concerning any of the above, please contact
Kevin Peiffer at GINN, INC., 386-6611.
H. Wayne Ginn, P.E.
KP/HWG/sr
cc: Steve Goram
PSA Engineers
16135 Preston Road · Suite 106 · Dallas, Texas 75248 · Phone 214/386-6611