The Madison Water Utility said it recorded the most water main breaks last year since the agency began keeping records 33 years ago.
City water utility spokeswoman Amy Barrilleaux said crews repaired 306 main breaks in 2013, up from 221 in 2012. She said the spike in main breaks is due to a combination of extreme weather and aging water infrastructure.
Barrilleaux said many of Madison's water mains date back to post-World War II years and are made of a brittle material called spun-cast iron that tends to break. She said as the ground freezes and thaws, soil expands and contracts causing pressure to the pipes.
The pipes in service for more than six decades have reached the end of their useful life, according to the utility. The department has plans to replace about 400 miles of pipe over the next six years at a cost of more than $12.5 million.
Barrilleaux said the city spent $7.5 million in 2013 to replace mains.