What Happens To SoCal Water If The Big One Hits?

Feb 12, 2019

KVCR's Benjamin Purper and Lillian Vasquez take a tour of the Sterling Pump Station given by Craig Miller, General Manager of Western Municipal Water District.
Credit Lynne Butler / Western Municipal Water District

Southern California gets much of its water supply from Northern California - so what will happen if the "Big One" - a major earthquake - cuts that supply off?  KVCR's Benjamin Purper finds out in  this report.

I’m touring a construction site near Western Municipal Water District’s headquarters in Riverside. The water district is expanding a facility called the Arlington Desalter, which could provide fresh water to customers in the event of a large earthquake.

Craig Miller, General Manager of the water district, says desalters like this pump up water from the ground and desalinate it.

Miller: “So you take an area of a groundwater basin that was maybe too salty to directly pump out and deliver to customers, so no one would want to touch that, so now we walk in and we say well we'll build a desalter. Which is basically like a sea-water de-salter that people are familiar with when you hear people talk about ocean de-sal. It's the same technology, but the beginning quality of the water is much less salty than ocean water, so we can do a lot cheaper than ocean de-sal.”

Once expanded, the Arlington desalter will provide 6.4 million gallons per day of water for the region. But the desalter doesn’t just provide another water source.

Miller: It also helps clean up that groundwater basin. So someday our grandkids are going to be appreciative of the fact that we started taking the salty water out of the ground, it gets replaced by better quality water. So someday you may be able to turn off these de-salters and your cost of water would actually go down.”

Miller says that Southern California relies on imported water from Northern California to get all the water it needs.

Miller: “I think the customers lose track of the fact that they live in a desert. And the reason they're able to live that lifestyle and use water the way they use it is because of the success of the water agencies. And our ability to import water into the area and maximize the use of groundwater. That's expensive. And there's a price to pay to live that lifestyle and to live where you live.”

Miller says if that water supply from the North gets cut by a major earthquake, it will be important to have groundwater resources like this one.

Miller:None of us know what the Big One's gonna be, and where exactly it's going to hit. We need that insurance policy of another source. Cause if that water went off for two months, we have to have enough water to survive without it.”

But Western isn’t the only district preparing for the Big One. While Western Municipal Water District covers parts of Riverside County including Temecula and Corona, Metropolitan Water District covers most of the rest of Southern California. They serve water to Ventura, Los Angeles, Orange, San Bernardino, and Riverside Counties.

Brent Yamasaki is the Assistant Group Manager of System Operations for the Metropolitan Water District. He says it’s hard to know what will happen when the Big One hits, but that the water district does have some contingency plans in place.

Yamasaki: “So if an earthquake were to cut us off from Northern California water supplies, we have other options including our own aqueduct that we own and operate from the Colorado River. And that supplies roughly about a quarter of all the water that's used every year in Southern California.”

Yamasaki says the Metropolitan Water District’s back-up sources could provide most of Southern California with a six-month supply of water.

Yamasaki: “Our storage policy is that we always maintain an emergency storage amount of six months of supply. So that amount that's in our storage reservoirs in addition to groundwater that's already here in the ground locally would be able to supply customers for six months at a minimum.”