Pond Boss Forums POND CONSTRUCTION Creating habitat how deep to prevent winterkill

Barbara - You will probably get numerous opinions about this question. 8ft - 10 ft deep along the entire bottom is probably adequate IF as Theo suggests and Wood strongly testifies to, you religously remove snow from the ice esp when snow cover is greater than 3"-4" deep. This may be an unacceptable task for your situation. In that case then the rule of thumb from me is, the deeper the pond is the less likely a winter kill will occur. 20-22 ft deep is not too deep in your situation with trout.

At 2:1 down slope of the sides and in a pond 50 ft WIDE the maximum depth feasable will be 12 ft deep. Example it will take 24 linear feet of distance to dig down 12 ft deep using a slope of 2' out and one ft down. Excavating side slopes steeper than 2:1 are possible but it usually cannot be done with a bulldozer. In cases of steeper slopes than 2:1 a track hoe with a bucket will have to do the digging. If that happens the chance of the pond leaking is always a big risk. Soil types primarily determine the amount of this leakage risk from just digging a hole in the ground as compared to pond basin that is compacted with equipment driving over the sides and bottom.

PS - Have your trout been dying from winter kill or summer kill?. Are you sure your trout survive your summers? The High muck buildup on the pond bottom no doubt causes a big disolved oxygen sag or depletion in the winter. Trout will be really stressed when the dissolved oxygen drops below 5 ppm (mg/L) whereas warm water fish will easily live at 3ppm.