I almost forgot. I have a very bad beaver problem. Over the past two years the beavers had made two dams. (One on the overflow tube and one on the inflow) I recently had those dug out with a backhoe, and was wondering if it was just a matter of time before they damed it up again. What is the best way to get rid of the beavers? Also the pond is now taken over by cattails. In some places it extends off shore 20 feet! How do I get rid of cattails?