Bay Area braces for own water main emergency

Byby Elissa Harrington KGO logo
Thursday, July 31, 2014
Bay Area braces for own water main accident
Construction on the Bay Area's aging water infrastructure.

EAST PALO ALTO, Calif. (KGO) -- A leaking pipe from the Bay Area's aging water infrastructure has been leaking fresh water into the bay for four years now near the Dumbarton Bridge.

It's leaking at a rate of 25 gallons per minute.

It is just one of the many old, deteriorating pipelines in the Bay Area in desperate need of a fix.

In 2011, a water main broke in South San Francisco sending a geyser 60 feet in the air. People had to be rescued from their homes.

In 2012, a 78-year-old pipe split in Daly City, dumping thousands of gallons of water into a neighborhood.

In June, water rushed downhill in Potrero Hill. It broke during pressure testing.

Tyrone Jue, spokesman for the San Francisco Public Utilities Commission says some pipelines in the Bay Area date back to the 1920s.

"So, any sort of, you know, major shock to it could just cause a separation and a break," he said.

Utility crews are on track to repair 15 miles of aging pipeline each year. One of the biggest jobs is the Bay Tunnel Project near the Dumbarton Bridge. Tunnels will pump Hetch Hetchy water to the Peninsula and San Francisco.

"It's unfortunate because you never want to have a leak, especially during a drought, but in this case we're waiting for the bigger fix to take place," said Jue.

Jue says there's no quick off switch.

"You can't close the valve right away because you get a water hammer effect. What a water hammer effect is, you snap off the flow of water immediately. The water hits an immoveable object and then reverberates back through the system, causing shockwaves, essentially, to blow other connections," he said.

The key is to gradually decrease pressure. Jue wouldn't speculate if crews here could respond faster, but did say they are on standby 24 hours a day.