Outlet pipe from detention basin will have tailwater....what to do?
Outlet pipe from detention basin will have tailwater....what to do?
(OP)
Hello everyone,
The detention basin has an outlet structure of a 3' x 3' box, with a V-notch weir on the entrance side and a 12" RCP stubbed into the opposite wall. I work with HEC-HMS. The pipe has a very flat slope (0.26%); it has tailwater. How would I figure the discharge going through the V-notch weir and over the top of the box - all before flowing into the pipe? Will HMS work? Or would you rather I use some other software or do hand calculations?
Thank you,
Bills Sis
The detention basin has an outlet structure of a 3' x 3' box, with a V-notch weir on the entrance side and a 12" RCP stubbed into the opposite wall. I work with HEC-HMS. The pipe has a very flat slope (0.26%); it has tailwater. How would I figure the discharge going through the V-notch weir and over the top of the box - all before flowing into the pipe? Will HMS work? Or would you rather I use some other software or do hand calculations?
Thank you,
Bills Sis





RE: Outlet pipe from detention basin will have tailwater....what to do?
RE: Outlet pipe from detention basin will have tailwater....what to do?
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: Outlet pipe from detention basin will have tailwater....what to do?
for a spillway or weir, it might be easiest to input an elevation-discharge curve
if you have tail-water on your v-notch, suggest that this is not the best design. v-notch's should be designed without tail-water. Unlikely that you will be able to predict the discharge coefficient for a v-notch weir with submerged nappe.
RE: Outlet pipe from detention basin will have tailwater....what to do?
Thanks again!
RE: Outlet pipe from detention basin will have tailwater....what to do?
Found this one: http://www.fs.fed.us/biology/nsaec/fishxing/fplibr...