Historic low water levels at Lake Oroville will not impact the Santa Clarita Valley’s water supply this year, according to the Santa Clarita Valley Water Agency.

Dirk Marks, director of water resources for the agency, said that the water from Oroville, located in Northern California, represented 5% of the water the agency is contracted to receive from the State Water Project.

SWP sites include Oroville, Castaic Lake and many other locations and facilities in between that help transport water from Northern California to Southern California.

Last week, the State Water Resources Control Board issued an emergency order giving it the power to curtail water holder rights in the Sacramento-San Joaquin Delta.

Though SCV Water doesn’t have water rights in the Delta, its water supply from the State Water Project comes from Lake Oroville, through the Delta, according to Kathie Martin, spokeswoman for SCV Water.

“We are relying a lot of banked water supplies and other sources that we have,” said Marks, noting that SCV Water receives between 55% to 60% of its SWP allocation during average rainfall years. “We’ve made up the difference because we have a very diversified water supply portfolio.”

In addition to the water imported from Northern California, SCV Water receives water from Buena Vista and Rosedale Rio Bravo water storage districts in Kern County.

Marks said the water from the districts in Kern are more expensive than the water from the SWP.

“To the extent that our customers are enabled to conserve water, that means there’s less of this expensive water supply that we’ll be accessing,” he said.

The agency also uses local groundwater sources, some recycled water and groundwater banking, which involves “storing available SWP surface water supplies during wet years in groundwater basins,” according to SCV Water’s 2020 Urban Water Management Plan.

The historic low water elevation at Lake Oroville has implications for 2022 as well, Marks said.

“The hydrologists are telling us that if we have normal or average perception in 2022, that that would probably still only result in a 20% allocation (from the SWP), as opposed to the 60% we would normally anticipate,” he said.

Watersheds are so dry, Marks said, that rainfall in 2022 will be absorbed by the soil. And with 2022 likely being another dry year, SCV Water will need to pull from its groundwater banks again.

“The benefit of conserving water now is that leaves additional water in 2022, 2023 and 2024,” said Marks.

Martin said customers could learn more about conserving water online at droughtreadyscv.com.

Castaic Lake drawdown

The California Department of Water Resources announced last week that construction started on the Castaic Dam tower access bridge.

The improvements will strengthen the bridge “to reduce seismic risks during a major earthquake,” according to a DWR news release.

Advance work on the 500-foot-long bridge required a “temporary drawdown” in May that reduced the water level of Castaic Lake, a manmade body of water completed in 1974, by more than 100 feet.

“Castaic Dam’s intake tower access bridge work is expected to continue until spring 2022, then Castaic Lake will return to normal operations with water levels based on available hydrologic conditions at that time,” stated DWR’s statement.

DWR also urged recreational users of the lake to follow advisory signs, and be aware that boating capacity could be limited during the drawdown.

SCV Water has rights to 3% of the water in Castaic Lake.