A number of years ago I totally re-plumbed the house I am currently living in. I also replaced the water line into the house from the street. I have been in the Northwest long enough to realize that the pipes are not buried deep enough for extreme temperature lows that do occur, so I buried the pipe three feet below ground. Subsequently the city put water meters in and started to bill based on usage instead of flat rate. The next winter we lost our water due to the water line freezing at the water meter. The city insulated the meter box with sawdust, a common practice used by cities in the Northwest. But prior to the freezing weather it had rained causing the sawdust to lose all its insulating powers. After thawing the pipes at the meter with a heat gun, I replaced the sawdust with non degradable packing pellets. It never froze again. If I had let a little water drip, I could have avoided the problem but it is hard to do that after spending so much time replacing leaking plumbing.