CEDAR RAPIDS, Iowa - The drought is one potential cause for an increase in water main breaks in Cedar Rapids, officials said.

The cause of multiple water main breaks Thursday afternoon in southwest Cedar Rapids that left about 150 residents without water, has yet to be determined. Officials are investigating several potential causes, such as a power disturbance at a water plant, 761 J Avenue NE around 2:30 p.m. which can trigger a water hammer, or a "mini-tsunami in the pipe." As well as the history of the area the water main breaks occurred, since some of the pipes are from the post World War II era and have created problems in the past, officials said. Officials are also looking into drought related causes.

"Certainly the drought this past summer has a role in the number of breaks that we have seen so far this year," Utilities Environmental Manager Steve Hershner said. According to officials, Cedar Rapids had 15 water main breaks or leaks currently in October, the highest in at least six years. Last October, Cedar Rapids had 10 water main breaks or leaks, and four in 2010.

We are already looking at a pretty big year, Hershner added.

City of Cedar Rapids Communications and Educator Director Megan Murphy said the City of Cedar Rapids is experiencing about the same number of main breaks that occur in the middle of winter. "Colder weather typically gives you freeze/thaw conditions, which causes expansion and contraction that can affect even some buried pipes," Hershner said. "Drought conditions can cause drying and settling, which can have similar expansion and contraction effects on water system piping."

During the drought, specifically in June 2012, average maximum temperatures increased by almost 10 degrees Celsius with half the amount of greatest rainfall in a 24 hour period than in June 2011, according to the National Weather Service. Officials reported 21 water main breaks or leaks in June 2012, surpassing June 2011 and 2010 that reported only four.

Crews spent roughly 10 hours Thursday investigating and repairing the four broken water mains near Wilson Avenue from 18th Street to Hughes Drive SW. Water was restored to most residents around midnight, with an exception to the 8th Avenue SW water main that didn't restore water until about 1:30 a.m. Crews had to dig about six feet underground to locate the water line that is buried deep to protect it from frost to discover what was needed in terms of repair.

"Last night each repair required the pipe to be cut and replaced," Murphy said. "When this repair is needed they cut out the damaged section of pipe, put a new section of pipe in and two sleeves over each joint." The sleeves are epoxy coated steel with stainless steel bolts to resist corrosion. "These repairs are designed to last until the water main is replaced. In general, the City expects to get 100 years of service out of a water main." Murphy said.

After a pipe is repaired, the section is then flushed to remove any sediment and the hole is filled. Murphy added if any streets or driveways were damaged in this process they will be repaired or replaced by the Cedar Rapids Water Division. Officials also examine the history of the area of the main break to see how frequent breaks are occurring.

"If we are starting to see an increased number of breaks on a particular main, it is scheduled for replacement as a Capital Improvement Project," Murphy said. "We then coordinate with other city utilities: sewer, streets, to see if these services also need repair or replacement." Coordinating the projects will ideally save time, money and limit inconvenience for the neighborhood.

"We are still reviewing these areas to determine if these particular mains are experiencing enough breaks to warrant replacement of the entire pipe," Hershner said.

The incident remains under investigation.