Quarter my comment on the settlement pond wasn't necessarily dealing with the flow through issue. But to suggest a way to drop out the heaviest of sediment. A pump with a long pipe on the discharge could be used to stir up any muck in the deepest part of the pond during a flow through event. That would help keep your pond from filling in. That's what I do during a flow through event. It is much easier to remove the heaviest sediment from a small pond that either dries up or can be drained into the larger pond.
