15 million gallons of water lost in San Bruno main break

SAN BRUNO, Calif. (KGO) -- In this drought, you hate to see any water being wasted, but that is what happened on the Peninsula.

Millions of gallons of water were lost after a 54-inch regional transmission line broke Monday night in San Bruno. Crews finally shut it off Tuesday morning.

The water main break was discovered shortly after 9:30 p.m. at the Junipero Serra County Park in San Bruno.

"It appears that age is the cause of the break. This pipe was built around 1927," Deborah Chilvers, a spokesperson for the San Francisco Public Utilities Commission, said.

Crews were finally able to cap it 13 hours later after diverting the water, which comes from the Crystal Springs Reservoir.

You can fill 20,000 bath tubs with one million gallons of water; now imagine 15 million gallons. The amount lost represents 20 percent of the water that serves San Francisco in a day.

Still, the San Francisco Public Utilities Commission decided it would be much worse to shut the line down used in San Bruno, Pacifica and by the San Bruno jail.

"It would have depressurized the system all the way down the line, so all of the communities that were fed off this pipeline would no longer have had water and it's not only your home and drinking water, it's all of those hydrants on the corner of every street," Tyrone Jue, SFPUC spokesperson, said.

Keeping the system flowing is what helps keep the drinking water safe for residents.

"If the water gets depressurized then the system has to be chlorinated again, so you need that chlorine residual in the pipes to keep the water quality where it needs to be," Jue said.

Because the break occurred inside the park, the water was able to flow into an existing creek and eventually into a storm drain leading into the bay.

Customers should not expect a fee hike. These kinds are events are covered by the water agency's emergency fund.