That's exactly the same situation here but way bigger levees. We also have the beaver issues here. Nothing like having to dig a dam out of a 4-6' diameter culvert in a drainage canal by hand while inside the culvert! From what I've been told by the old timers when badgers move in to an area the woodchucks move out!
I feel for you, Man. All the while you're digging out the dam, the beavers are already working to put it back together. They probably don't even wait for you to leave, do they ? I think that's probably true about the badgers running the woodchucks out. They just have a really mean disposition, and a woodchuck is a pretty docile animal. It's probably about like how the foxes go away when the coyotes show up on the scene. They either scare them away or they eat them.
The only time I ever even heard of a woodchuck in the 25 years I hunted deer up there with those guys was when my buddy had one set up camp in one of his grain bins. It was making an awful mess, digging up the foundation. He was telling me about it over coffee as I was getting ready to leave after one of our annual deer hunts. He had tried the Havahart trap, with no luck. He asked me how to get it out of there, and told him I only know of one way to deal with a woodchuck. So, he came back with the 22, ready to go. I told him that he had better shoot him in the head, or it would go back in the hole and die in there. Then the grain bin is going to stink like a rotting carcass. If you want him dead right now, so you can get rid of the carcass, something a little bigger might be advisable. He also had one of those short-legged beach chairs, and was all ready to wait this one out. I asked him if he had some free time, because this one isn't going to be seen again until about April. The look on his face was priceless. He said "April ??? I'll be frozen stiff as a board by then." ( It was mid-November when we were having the conversation about it.)
So, he made a plan to park himself in the empty grain bin, and wait for as long as it took to let the air out of that little digger that was causing so much trouble. I had told him how they like apples, and he called me up in late March and said that the ones he had left out had been munched on. Time for our hunt. I asked him what weapon he had chosen, and he said that he was going to use …...… his slug gun. "WHAT ??? For a ten-pound rodent ? Don't you have something a little smaller ?" "Geez," he said. "There's just no pleasing you, is there. I told you I have a 22." Well, I guess that he had never read Goldilocks and the three bears as a kid, and had no concept of "just right." I also asked him if he had some ear plugs, since when you shoot that big gun inside a grain bin you aren't going to be able to hear anything for about a week. He said that would be OK, since his wife was getting kinda cranky from being stuck inside with him all winter, and maybe if he got a little relief from her constant badgering it would be good for him. "Shucks," he said. "Why do you think I've been looking forward to going out and sitting in my grain bin so much ? She's been downright hostile for about a month already."
So, he went out and did the job on Mr. Woodchuck, which didn't take as long as we had thought it would. One thermos of coffee was enough to get the job done. His buddy's 22 magnum was the perfect tool for the job, and all was well in the end. He sent me a picture, and I responded "Yup. That's a woodchuck, all right. Nice job." It was about twice as big as any I had ever seen before, so I guess life in the grain bin had been good to him. My buddy did have to move the grain bin, but he had kinda wanted to do that anyway. He now knows everything he had ever wanted to know about woodchucks, and the boys down at the grain elevator are still talking about it at their morning coffee breaks, when all the farmers show up to reconnoiter for a bit. Those guys are a bunch of characters anyway, and stuff like this gives them something to mull over in their slack time.