I hate woodchucks even more than squirrels. I used to live alongside a riverbank in North Dakota. Got a call from a neighbor early one morning that water was coming in through a hole in the dike. Fortunately, I got it patched up in time, but it turned out to be a woodchuck hole. Went on a hunting expedition for a couple of months afterward. Any that I didn't get with my .22 got caught in a live trap and drowned in the water trough-- if they didn't expire from heat exhaustion before I found them.
Woodchucks, I learned, have an irresistible taste for apples and very poor heat tolerance. I highly recommend live traps which open at both ends.