Iowa City sees water pipes break in aging infrastructure


Iowa water infrastructure experts discuss the challenges of aging infrastructure and what is being done to fix the problem and reduce costs.

Larry Phan

A drain pipe is seen in Iowa City on Monday, Feb. 14, 2022.

Water main breaks in Iowa City are causing increased expense and labor to update decades-old infrastructure.

In Iowa City, 47 water pipes burst from November 2020 to March 2021, and another 20 broke this winter.

Water main repairs cost an average of $4,000 to $5,000 and typically require about six hours of labor from seven maintenance workers, said Michael Willis, a senior maintenance worker for the division. waters of the city of Iowa.

Willis said the number of breaks per year tends to move cyclically.

“We average 60 breaks a year,” Willis said. “We can be as high as 81 or 82. And if we have really good conditions and nice even temperatures, we could be as low as 30 or 40.”

Breaks during the winter are usually due to ground heaving, the movement of the ground caused by repeated thawing and freezing, which puts additional stress on water lines, Willis said.

Other contributing factors include pipe age, corrosion and pipe material, Willis said.

Some water lines in Iowa City date back to the late 1800s, he said. However, most recent breaks have occurred in those installed in the 1960s and 1970s.

“After World War II, there was a shortage of iron,” Willis said. “So they were looking for ways to make the water pipes thinner.”

Justin Clausen, public works operations manager for the town of Ames, said the shortage was further extended with the Korean War and, to some extent, the Vietnam War.

Ames averages about 32 major breaks per year, Clausen said, many of which occur in pipes installed after World War II from the 1950s through the 1970s.

“The water pipes of the 20s and 30s might not be what you want from a capacity or firefighting standpoint, because they are generally smaller water pipes,” said he declared. “…But structurally, they’re actually in better shape than some of the ones from the 50s and 60s.”

Clausen said weakened water pipes are also more vulnerable to ruptures from water hammer, the sudden stoppage of water movement, caused by a closed valve.

Willis said capital improvement projects allow the Iowa City Water Department to replace weaker parts of the tops of water pipes to prevent breaks.

“There are always more water pipes to replace than we have funding available,” Willis said.

The majority of the newly installed pipes are plastic and have had no problems with breaking, he said.

Greg Metternich, superintendent of water for the city of North Liberty, said that in his 26 years on the job, his city has experienced only three water main breaks, all caused by human error. He said North Liberty’s main water system is made mostly of plastic.

“[Plastic] is going to give you a bit more leeway when the ground starts to move,” Metternich said.

Metternich said the oldest parts of North Liberty’s water pipes were built in the late 1970s when plastic water pipes were coming into widespread use.

Clausen said Ames also installed plastic water pipes.

“Our percentage of plastic water pipes is probably close to 45%,” he said. “…and so far [it] turned out very well for us.


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