Thanks everyone for your responses.
Swearingen and JedClampett: I think you're both agreeing that the hydrostatic force will be the trapezoidal pressure diagram equal to the height of the fence but based on the total depth of water. See the attached calculation.
Sam74: my dissipator is at the...
I am designing a debris fence to be constructed across a channel at the downstream end of a rock energy dissipator. The fence is to be constructed with chain link fabric on heavy steel pipe posts. The fence will be 3 feet high to catch the first flush debris during a 5-yr to 10-yr storms and...