Over at the Columnist Manifesto, Oscar Madison casually used a word for something I didn't have a word for: It's the (sometimes massive) row of snow that a plow leaves blocking your driveway. He called it a berm, and in fact 'snow berm' gets a lot of g-hits, including from municipal websites stating policies about this. People usually call the big piles along the side of the road a snow bank, but that's awkward when it's a relatively small amount. (Bank doesn't work for 6 or 8 inches of snow, only big amounts!) I had learned the phrase to be plowed in for driveways years ago, but lacked a noun for the situation.
Image from this Forest Service website. (I would have happily called that a snow bank.)