IOWA CITY — The communities of Iowa City and Cedar Rapids have seen a historic or near historic number of water mains break this January, officials say, and the month isn't even over.
The extreme variations in weather, which has swung 59 degrees this month, is taking its toll on the pipes, some say.
"Just like Cedar Rapids, we are in the century club," Ed Moreno, Iowa City water division superintendent, said referring to problems due to old pipes.
Iowa City has had 26 water main breaks since Jan. 1, including a break on F Street and Summit Street on Thursday, according records. That's near the record high of 28 in 1994, well above the average of nine breaks each January in the past decade, Moreno said.
Cedar Rapids has had a record high 40 water main breaks since the beginning of January, which is up from a January average of 16, according to a KCRG report on Thursday.
Moreno said a concentration of the problems are with cast iron pipes laid from post World War II until the 1970s. Cast iron pipes older than that era were thicker, and newer pipes made out of ductile iron and most recently, PVC, have generally withstood the changing conditions, he said.
Moreno said crews are on call day and night for repairs, which can take three to six hours. Because it's so cold, the escaping water can freeze around the pipes, complicating the fix and adding an element of danger to the job, he said.
Thus far the breaks have cost the city $35,000 and the total will increase when the jobs are completed in the spring.
Dave Claman, a governor for the South Dakota/Iowa chapter of the American Society of Civil Engineers and also a design section leader for the Iowa Department of Transportation, agrees the shifting ground due to temperature changes are to blame.
Claman said the extreme cold, which has bottomed out at minus 17 on January 7, according to the KCRG-TV9 First Alert Storm Team, pushes frost deeper into the ground. The frozen ground adds pressure on the pipes, which are already pressurized to deliver water. When the cold snap breaks — we've had two days that have hit 42, according to KCRG records — the pressure drops causing the ground around the pipe to shift, he said.
"If it's always cold or always warm it would be OK, but when it keeps switching from frozen to non-frozen, the ground moves causing the pipes to break," said Claman, noting the similarity to the spike in potholes in the spring.
Hiawatha has also seen an uptick with five breaks this month, compared to two or three in a typical winter season, said Sara Ries, with the Hiawatha Water Department.
Officials in Marion, Coralville and North Liberty, which are younger communities, report minimal or below average breaks. In Marion, there's been nine breaks down from 13 in January 2013; Coralville reports two burst water main all winter season well below the January average of six to nine breaks, and North Liberty has had zero breaks."We are pretty fortunate, even our older stuff is plastic," said Greg Metternich, water superintendent in North Liberty. "Relatively speaking, the oldest parts of the system were put in in the 1970s."