Building a pond

I wish Riggs was still around. he had a nice set up. He isnt all that far from you Stu.....

Ryan Bahn (Riggs) ryanjbahn@gmail.com

My neighbor built a pond on his land that backs up on my land. The soil is sandy and he basically just made a dam across a ravine that came from my land. This ravine has moving water coming from two seasonal springs on my land about half the year. During a drought the spring flow stops, but during heavy rainfall the runoff coming through the ravine can 6"+ at times. I didn't think the pond would be deep enough for fish to survive, but it did. I would guess at full capacity the pond was initially 20' deep. He stocked it with all sorts of fish he caught, including rainbow trout. They survived and my son caught one on our side of the property line that was 18".

They took about 2 years to grow from about 10" to 18". Then we had a dry year and the water level dropped (with no spring flow, the water level was likely determined by groundwater level and the water level dropped in the summer to the point where everything died). When the water level was low a year ago he brought in a larger excavator and dug out the deepest spot in the pond even further and now at the low groundwater level it is likely that the pond is still 15' deep and at full capacity likely over 30' deep. He has an aerator that is running year round and I think fish should now survive even dry years. This fall I brought in a bulldozer and excavator to dig a wildlife pond on the other side of my land and while he was there I also had him dig out the area on my side of the fence from my neighbor's pond. This work should triple the amount of water on my side of the fence when the pond is full. When the pond is at full capacity I should have about 1/4 acre on my side of the fence in addition to the 1/2 acre on his side.

I think the most cost effective way to build a pond is to build a dam like my neighbor did since you have to move less dirt. The downside of that design is that you either need to have clay soils to hold the water or need a constant water flow to replenish what is lost via seepage or evaporation. Bulldozer and excavator time here is about $1000/day, and I would guess my neighbor has $25k into his pond. I'd say that pond would increase his property value by far more than that, so it's really not a bad idea.

The USFWS wanted to build a shallow wildlife pond on my Wisconsin property, but since it was in a wetland the DNR wouldn't approve it (even though they all agreed adding a pond there would be better, anything with an existing wetland was rejected). A beaver family then build a dam almost exactly where the fish and wildlife guy wanted a dam and it turned into a nice duck pond. My kids love catching frogs, minnows and turtles there, but it freezes solid every winter so only mud minnows can survive. I think ponds are a great addition to any property and I'm always trying to find a way to add another one.

I’d like to dig out a few ponds .. nothing huge, but in low spots that will hold water .

You guessed right

What size of a pond have you had experience with keeping fish alive? I’m assuming there is a perimeter and depth tradeoff to keep in mind, but is a 1/4 or 1/2 acre large enough for a consistent population?

1/4 acre would be more than large enough to support fish if it was deep enough to prevent winterkill.