MANKATO — Occasionally, a big one breaks and wreaks havoc.
In Minneapolis, a 3-foot water main broke Thursday and flooded downtown. Businesses closed. Buses were rerouted. Entertainment events were canceled.
A break like that is no easy repair. And this time of year, you never know if and where one might occur.
“It’s always a concern, especially the larger pipes,” said Tony Talamantez, Mankato Public Works Department infrastructure supervisor.
Talamantez said water main breaks can occur any time of year. But more happen during the winter. Just this week a break closed a section of Devonshire Place between Monks and Welcome avenues in Mankato.
Currently, conditions are favorable for such breaks to occur due to the lack of snow cover. Talamantez said often breaks occur when frost seeps into the ground and causes the ground to shift.
“When we don’t have a lot of snow cover, the frost can go down a bit deeper,” he said.
Talamantez said typical breaks to 6-inch cast iron pipes take four to six hours to repair. But larger breaks can take much longer.
A 12-inch water main break at Cherry and South Front streets last May took days to repair, causing the busy intersection to be closed. Water flooded the area, as well as the basement of at least one business.
About 13 feet of a 10-inch water pipe had to be replaced, Talamantez said. He suspected acidic soil weakened the pipe and water pressure blew a hole through it.
Talamantez said the city averages between 30 and 50 water main breaks per year.
The city collects about $12 million per year from water and wastewater revenues. That funding, which pays for operating the city’s water and sewer system, also is used to build a reserve to be used for water main repairs.