Jeff, if you don't want to partially drain, dig out the drain pipe and replace with proper compaction, don't mess around; get in touch with TJ asap.
I'd hate for you to come out one weekend and see a large gap where the drain pipe was, and have it all wadded up on the neighbors property, with a large chunk of the dam washed there too, along with the fish and water....
The cost of doing either fix is MUCH less then if you have to repair a washed out dam. Think of it as a cheap insurance policy. In my opinion, the longer the leak is there, the more fine dirt is washed out, making the leak worse. I think that's why you are seeing it getting larger.....
Compared to the money that has already been spent, protect your investment. Need I bring up the fish feeder?
