It's common. I've opened up my keezer to 3 inches of water before. I'm guessing yours is in a garage or basement. Mine is in my garage. I only get water in the summer.
It means there is an air leak somewhere. I 've caulked every seam in my keezer, sealed the collar, added dehumidifier, added a fan, and added additional weather stripping, but I still get a little water. It's a lot better than it used to be though.
One of the biggest culprits is opening and closing the freezer top. If you do this a lot, you'll never get rid of the condensation issues.