I have 80 acres and two ponds. Next year I plan on expanding/reworking these two ponds, plus adding another dozen ponds. The two existing dams use culverts to carry the water across the dam. On both dams, the culverts have lots of problems. On the upper pond, the culvert is high and frost heaves in the winter move it. Two winters ago the culvert was heaved so that the intake was higher than the dam and water ran over the top of the dam. Plus water finds its way around the culvert and is starting to erode the dam. On the lower pond, water is finding its way around the culvert and is starting to erode the dam. In the summer, the amount of water flow here is very small. So small, that the water tends to go underground in many places. The water running into the upper pond is pretty good. The runoff from that pond eventually ends up at the lower pond where the water running into that pond is zero. Without fresh water, the water becomes warm and oxygen becomes too low, making aquaculture projects difficult if not impossible. I'm thinking that the solution is to make series of ponds with the runoff from any pond running into something water tight and carrying the water to the next pond. Either a poly pipe (which wouldn't be enough for the spring flow, but enough for summer) or a series of cement/tufa catch basins/troughs. Each of these ideas has problems, not to mention expense. Any suggestions?