redesigning small pond overflow - 05/18/22 08:27 PM
My 20+ year old pond is around 3/16 acre at max pool. Currently the overflow is just a 8foot long piece of 10 inch corrugated culvert pipe with the top at lawn level. The outlet from the pipe is a barely existent ditch that runs 200' to the county drain by the road. Currently there is around 18" of drop from the overflow to the road. The system is so old and overgrown that the pond gets too high and makes the banks and yard a quagmire. When it dries out enough to dig the ditch out without getting the tractor stuck I am going to try to lower the ditch a good foot maybe two at the road and dig out the rest to get some more aggressive fall. The part I'm not sure about is the overflow system. The culvert is fairly easy to block with leaves as I need a fairly tight screen to keep the fish from swimming downstream into the ditch and ultimately ending up dead in my front yard when the water level drops. Because of the marginal ditch currently during heavy rain events, the water in the ditch will actually flow back through the culvert into the pond and I want to prohibit that. I don't really want to have to dig out the bank to put in a reverse siphon pipe if I don't have to. I was thinking to try to make a spillway around 4feet wide with the idea that I can easily keep that clean and the overflowing water shouldn't be very deep over top of the spillway so maybe fish won't escape?