To repair a farm pond leak, pour a slurry of bentonite clay over the surface of the pond. If the clay, which expands and fills in cracks, does not fix the leak, drain the pond, and determine if major repairs are necessary.
- Use bentonite clay
You need 1 pound of clay for every square foot of surface area. If your pond is deep or the soil is very porous, you need to double this amount, using 2 pounds of clay for each square foot. To make a slurry, mix the bentonite clay with water. Spread the slurry over the surface of the water. The clay sinks to the bottom of the pond and fills in the crack as it expands in size.
- Drain the pond
If the drain pipe is damaged or the bentonite slurry did not help the leak, drain the pond, and inspect it.
- Make major repairs, if necessary
If you see leaking near the area of the drain pipe, the pipe may be damaged or misaligned. If needed, reinstall or replace the drain pipe with an antiseep collar. Bentonite can repair some dam leaks, but if the damage is extensive, the dam may need to be rebuilt or replaced. If the ground is the source of the leaks, applying clay, manure or chemical dispersant to the surface can cure and seal the soil.