I met with our pond guy this morning. We are going to try to do a new core or "cutoff wall" of clay on the back side of the dam at about full pool level using a dozer and full sized backhoe. He thinks the problem is likely the rotting roots from trees and trumpet vines that were on the dam at the time of renovation. At the time, the back side toe of the dam was inaccessible due to brush, an old woven wire fence and the previous neighboring owner. The brush and fence have since been cleared, the line established, and the property changed hands to a friendly owner.