While cold weather poses a threat to the water pipes in your home, city water systems are also susceptible to the cold weather. Several Iowa communities have experienced water main breaks in recent days. Randy Beavers of the Des Moines Water Works says frost is the culprit. He says the frost causes the ground to shift well below the ground where water pipes are buried. He says mains that have rust are most susceptible to breaks. A system as big as Des Moines’ has problems throughout the winter, but Beavers says it gets worse with the subzero temps we’ve had recently. He says they average one to two breaks a day during a normal winter, and that increases with colder weather. Beavers says Thursday they had 10 water main breaks during the frigid temperatures. Beavers says older pipes can cause more problems.He says the industry standard prior to 1970 was some type of iron. Beavers says they’re hoping a new material that’s replacing the metal pipes will hold up better.He says they now use plastic pipe and hope it will be the answer to cutting back on the breaks. But Beavers says most communities replace the metal pipe with plastic as it breaks. The tiny town of Alburnette reported four water main breaks within the last several days, shutting off water to parts of the community over that period.