Portland Water Bureau crews are working to repair a main break on SW Vista Avenue between SW Elm Street and SW Spring Street.

Just after midnight, an eight-inch cast iron main installed in 1927 ruptured, causing water to flow into the street. At this time, water to the broken pipe has been shutdown.

No flooding damage has been reported. However, water pressure is affected in the immediate area.

SW Vista Avenue, a residential street, between SW Elm Street and SW Spring Street is closed except to local residents. Traffic will be detoured around the work zone.

Crews will be on-scene until work is completed.

The Water Bureau's Maintenance & Construction crews are called out at all hours day and night to repair broken water mains, an average of 200 times a year.

In Portland, cast iron water mains tend to break during the colder times of the year. Cold water can cause pipes to become more brittle. Adding cold air temperatures at or below freezing can cause the ground above a pipe to freeze, thereby increasing external stress on a pipe. Temperature can be just one factor in causing a main break; the age of the pipe, soil conditions, pipe corrosion and ground movement can cause a main to weaken over time and break.