John Fitzgerald - What are you calling a sump? Just a deep well type holding hole? What's the benefit in collecting it that way rather than pushing it over the dam the first time? Just gathering info.
ALSO - " Make sure all disturbed areas are well compacted during the completion phase, especially the cut in the dam. I am still dealing with excessive seepage due to poor compaction and failure to take out all tree roots" this is kind of what I am renovating for. Core is leaking through stumps grown on the backside of the damn..and I believe muskrat holes. Combine that with a 50-60 year pond...and the decay is extensive.
The direction the muck needed to be pushed was over a solid, non compromised part of the dam. What I am calling a "sump" was a big round hole.
The dozer couldn't push the muck uphill that far without losing both traction and some of the muck. We dug that big round hole with the large Case backhoe to make the lip of the hole even with the bottom of the pond. The dozer pushed the muck into the hole, and the backhoe dipped it out. After the muck was out of the pond, the hole was filled with good clay. I had trees on the backside of the pond and on the dam.
The roots were not removed, only the upper root ball was pushed out from the trees on the dam, so I have extensive seeping starting when the pond is within about 30 inches of full pool. The two large elm trees and one locust behind the dam died from flooding the roots, and they had to be cut.
I suspect those roots, plus roots from some trumpet vines that used to be there, are causing the seeps.
