Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? Pond is in baaaaad shape

Welcome Eggroll! To expound on what Rex said, you will have to excavate both directions from where the levee (or dam) washed out until you reach the properly compacted clay core. That's what you have to tie together with good clay that you'll compact with a jumping jack tamper, in no more than 6" lifts. If you don't find a good clay core in your dam (levee) then you've got a bigger job ahead of you.

I'm assuming that the 12" culvert wasn't big enough to handle the amount of rain and runoff that you got, and the dam washed out in the emergency spillway area. If that's the case, then as long as the water is down, I'd remove the existing culvert and install a larger one, properly compacting the clay around it, and also installing anti-seep collars on it. That will take some pressure off of your emergency spillway.