Hunterwood-CS 840813GINN, INC.
CONSULTING ENGINEERS
TO:
FRON:
DATE:
SUBJECT:
Hr. Hark S~eeney
Coppell, Texas
OINlq, ~NC., 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 coed,htS.
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 recon~nended.
2. Sho~ 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 (Technica~ Paper #&0).
5. Keep velocity in 18" diameter RCPLateral 12.5 fps or less (if
possible).
6. Ne~Property ditch line - add note - "grade to drain," sho~ns flow
arrow~.
If you have any questions concerning any of the above, please contact
Kevin Peiffer at GINN, iNC., 386-6611.
H. Wayne Oinn, P.E.
cc: Steve Corem
l~aA End,ne,rs
16135 Preston Road · Suite 106 · Dallas. Texas 75248 · Phone 214/386-6611