Of course there are all kinds of ways to get rid of your Capybara. From vent systems to berms to drainage hose buried around the pond perimeter. My point for Spartamets is that if you're going to run your pond year-round in a cold climate that you don't really have any way of knowing what's going on in the pond when it's covered in ice. The water can still drain from the pond while leaving the ice cover intact, making you think that you've got a normal water level. Seen it. Fixed it. That's why I wear a Mustang full-flotation suit for winter pond work (when I'm around, that is).