how to empty detention pond thru gravity if outfall is higher elevation

[delagina]

how to empty detention pond thru gravity if outfall is at higher elevation?

 

[peter246]

basically, you cannot do this by gravity (unless you could set up a siphon situation, which would be tricky to engineer/justify). even a siphon would probably not meet regulatory requirements.

pipe through the berm is the most common way, typically with a concrete structure within the pond to control the flow from the different design storms (i.e. 1-yr, 10-yr, 100-yr storms). what jurisdiction (country/state) is the project located?

 

[cvg]

pump

 

[Spartan5]

If you need to drain it temporarily, you can set up a siphon.