I understand. I have seen farm ponds in which the beavers and muskrats undermined the spillway race causing a huge erosion problem. Also seen where they repeatedly filled overflow pipes with debris. Definitely a major headache.

But in this case I don't want to save a pond, I want to destroy it. So I'm thinking that installing pipes might be the best long-term solution.

Though the Caddyshack solution is looking increasingly tempting.