Why is it

Why is it that this time of the year we seem to see all these water main breaks on the news? Blamed on the freezing temperatures? I don't get it? Huge volume of water, moving, buried...... Why would it be effected by freezing? Is it just typical of any time of the year but the press doesn't cover it other than freezing times?

ground shifts with heating and cooling. That is what causes most of the mains to break. At least that is what they told us in the classes I had

Dramatic changes in the moisture content of soil around old buried water pipes causes portions of the pipes to shift, and sometimes that shift is near a section of pipe that isn't moving. The result is a "break." It does not take ice to do the damage, and in fact, ice is seldom the first culprit.

This time of year, soil statewide has generally dried out as much as it is going to so when rain (or any other precip) lands, it will immediately be absorbed in the top soil layers causing uneven expansion. Only the clueless at you local news station actually think "ice" did the damage.

Yep...on a similar note, notice you tend to see a lot more broken down vehicles on the roadside when it get THIS cold? Same thing. Certain materials expand and retract to specs out of the norm.

Depends on a variety of factors, as a plumber who worked in New England freezing temps can cause problems. How deep the main was buried, the material the main was made of, the soil placed around the main, and one more is sloppy workmanship. When temperature gets cold, things constrict, if just for making things easy, one ton of soil is on and around the main. If there is a large rock, or the ground freezes quickly, that one ton will constrict and place pressure on the main. If it was back filled with rocky soil, those rocks can cause extreme pressure on a main, especially clay or iron pipe and cause it to snap. If you have ever used a pipe snapper on iron pipe, you’re slowly adding pressure around the pipe to make it snap, that’s one factor. Sloppy craftsmanship can cause it as well, if pipe isn’t seated properly at the joints and it was rushed, there could be voids allowing seepage, when freezing temps come, the joint starts to freeze then can cause a crack. Remember, if it’s under a road, how many vehicles are adding to the pressure as well. I’m not the guy who knows it all, but I’ve worked on main breaks and the variables I listed were usually the root cause... and yes, roots can cause a break too.