Temperature swings impacting infrastructure
GREEN BAY (WLUK) -- The temperature roller coaster we'll see in the coming days isn't just a pain for people - it can impact infrastructure as well.
A water main in Oshkosh broke early Tuesday morning across the street from Jefferson Elementary. The school was closed for the day while repairs were made.
The cause of the break, may partially be because of the weather we've seen lately. City officials say it's tough to know for sure, since the main could have been at least 90 years old. Overall they say this winter hasn't been too tough on mains there.
In Green Bay, it was a different story as the cold weather set in a couple weeks ago.
"Usually after about three days after a major temperature change, the ground will shift; we will see a a influx of main breaks. I think we had like 25 over the Christmas holidays and New Year's because of that cold snap," said general manager of Green Bay Water Utility, Nancy Quirk.
In most years, many of the breaks happen when temperatures transition from warm to cold, and vice-versa. That's because of the stress added to pipes underground when frost begins to form.
As one example: A pipe running from under a bare street to snow-covered soil. Frost forms much more quickly below the street than under the snow-covered soil. As the soil freezes, it expands.
That expansion then can put pressure on the pipes below it, and if the pipe is old or made of thinner metal, it can cause a break.
The ground below the street will also thaw out more quickly as the weather warms up, so then there's another difference in forces acting on the pipes along a short distance. This can also cause a break.
Since we've only just come out of a deep freeze, Quirk says there weren't any issues in Green Bay Tuesday.
And in speaking with a few other cities, it seems it was relatively quiet overall.
But as the temperatures transition back from warm to cold again, it's possible that could trigger another batch of breaks.