Pond Boss Forums POND CONSTRUCTION Soil questions dam leaking

I built my pond 3 years ago and it developed a leak above the 8 inch drain pipe that runs thru the dam. Directly above the 8 inch pipe about half way down the back side of the dam is where the leak is. I am sure the water has found a path along the 8 inch pipe. I no that the contractor did not use a collar. The leak is minimal about a gallon a minute due to the inflow it does not cause a problem. I want to patch the problem. I dont want to drain the lake. The area continues to wash out leaving a hole about 4 ft in diameter. I am thinking about digging the dirt out and filling with #5 rock about the size of golf balls and smaller. I am thinking that the water will filter thru the rock and that the rock will not wash creating yet another hole. I would place dirt back on the upper surface and re-seed.
Has anyone had a similar problem and if so what did you do. I would appreciate any comments back.

Thanks, Jake

Jake,
Dig out the hole, backfill with good clay, packed solid with a tamp. Be sure to install an anti-seep collar around your pipe.
I wouldn't use rocks. They aren't as structurally sound as solid packed clay.