Multiple breaks in water lines under the streets of Emeryville and Berkeley caused flooding Wednesday evening and left at least 300 customers without water overnight, according to East Bay water officials.
Christopher Tritto, a spokesman for East Bay Municipal Utility District, said an EBMUD operator "may have over-pressurized the system." In response to the leaks, Tritto said, EBMUD shut off water on some lines while it investigated and repaired the breaks.
Breaks also occurred in North Oakland and Albany, an EBMUD spokesman said, adding there were as many as 15 pipes being repaired.
Tritto said the utility expected to restore water service to all affected customers by 5 p.m. Thursday. He had no estimate of how much water had been lost and could not pinpoint where the breaks occurred.
The age and material used for the affected pipes are unknown. Tritto said operators constantly adjust pressure in water pipes in response to changes in demand during the day or night, and a valve used to adjust that pressure malfunctioned.
The Emeryville Police Department said in a statement that there appeared to be just one break in that city, near the intersection of Ocean Avenue and Hollis Street just south of 65th Street, and part of Hollis was closed while repairs were in progress.
The Berkeley Fire Department reported in a statement and on Twitter that there appeared to be breaks near four intersections: Pardee and Eighth streets, Dwight Way and Sacramento Street, Channing Way and Fourth Street and Sacramento south of Addison Street. The fire department said Sacramento Street would be closed between Addison and Allston streets for "several hours."
Twitter users posted photos of streets with standing water several inches deep, and Berkeley Fire Department urged drivers to be cautious when traveling on affected streets, which are in West Berkeley and near downtown.
Tritto noted that EBMUD manages more than 4,200 miles of water mains and smaller pipelines across the East Bay.
Customers will soon find information about the outage on the utility's website alert page here, Tritto said. Customers can call 866-403-2683 to report problems or obtain information.