Bridgewater sits on flat ground where the Town River wanders, and a storm parked over it can drop snow steadily for a day without much wind to move it around. Brian Healey Contractor Inc plows and clears through those hours, opening driveways and lots from Central Square out to the long country roads past the bogs. Depth is one problem and the plow bank at the end of the drive is another; both get dealt with before morning. Walks and entries are shoveled, and salt goes down where shade keeps ice alive past noon. What people want is simple — to back out and go — and that is what the night is for.