Pond Boss Forums POND CONSTRUCTION Building a dam cutoff trench, or core trench after the fact

This is my renovated pond (done Aug 2015). It's only about 18 feet from the toe of the dam to the property line on the south and west sides. I would need to get permission from the neighbor to the south to have the dozer temporarily move over the edge of his land...it's swampy anyway from my pond leak. The dam is all original except for the east side. That part was moved and extended about 30 feet eastward during the renovation process. The highest part of the dam is only about 5 feet above the original soil.

Here's a picture. The property line is the faint purple line on the south and west sides. North is at the top. This was taken Feb 2017, before the new pond filled. It's the excavation on the NE of the pond in question.