HEAD IN RESERVOIRS

[martin888888]

Hello,
I have two reservoirs being created in an extensive erosion control design. One sits with maximum water elevation of 200' while the other sits downhill with a maximum water elevation of 185'. They both discharge into the same pipeline which connects into an existing 12" at an elevation of 130'. The discharge pipe for the reservoirs lays flat and has a reverse slope in some spots, so we need to count on head to push water through.

Quaetion is would the head from the upstream pond at elevation of 200' have a tendency to try to back stormwater from the pipe into the 185' pond?

 

[77JQX]

You've provided insufficient information. It depends the hydraulic grade at the junction point common to the two reservoirs. It's possible they will both flow to the outfall, or it's possible the higher reservoir will overflow the lower. The higher will certainly overflow the lower if the common 12" discharge pipeline silts up or otherwise plugs.