Pond Boss Forums INTRO Questions & Observations Mechanical Means to Stop Wild Fish Contamination

I would do something like what Mfitzs70 suggested but with these mods.

I would construct a concrete lined hopper at an elevation above the pond of highest elevation. In the bottom of hopper I lay a grid PVC pipe with 1/4" Perfs. This grid would be connected to an outflow pipe (like 2" or 3" polypipe) and this would drain to the pond of greatest elevation. The grid of perfed pipe would then be covered in tamped peagravel and then a layer of size frac sand. You need an arrangement where the water pumped in does not disturb the sand and move it around(maybe something like large rocks). The hopper should have a drain that allows over pump to be discharged( which, if properly designed, should only happen when you need to clean the filter). The position of the hopper needs to be such that spillover doesn't drain into your pond(s).

I presume that the watershed feeding the ponds wouldn't normally be able to sustain the surface acreage but this doesn't mean that they can't overflow in uncommon rain events. For any pond discharging into water that flow directly to the creek, having some free-board and a siphon that lifts the water at the end (so that it exits in an arc) a concrete splatter structure can be built to spread the water in a spray horizontal to the ground. The structure should be long enough to handle distance traveled at maximum freeboard. If the pond spills at the spillway, the siphon isn't adequately designed or maintained. But these should cover you at both ends.