Runoff from the weekend’s big storm continued pouring into Lake Cachuma on Monday, and officials say they expect the reservoir to fill to capacity later this week.

When that happens, it will mark the first time in nearly two decades that Cachuma has spilled in back-to-back years, according to Matthew Young, Water Agency manager for Santa Barbara County.

The last time that happened was 2005 and 2006, Young told Noozhawk.

At midday Monday, the lake was about a foot below spill level, and was 97% full, according to the county Public Works Department.

In anticipation of the big storm, reservoir operators have been releasing water from Cachuma since last Thursday. They started out sending about 1,000 cubic feet per second (cfs) down the spillway, but boosted that to more than 7,000 cfs on Monday.

Bradbury Dam at Lake Cachuma is operated by the U.S. Bureau of Reclamation in coordination with the county.

“The bureau will slowly let the lake come up to full later this week,” Young said.

Gibraltar Reservoir and Jameson Lake upstream on the Santa Ynez River are both full and spilling, so all the runoff from the watershed will flow down into Cachuma.

Officials will monitor the flow on the river and other creeks feeding into the lake to determine how long to continue releasing water downstream from Cachuma, Young said.

“We were at roughly 90% full at Cachuma ahead of this storm,” Young said. “It’s nice to be in early February and know we will be finishing the season with a full Cachuma.”

A full Cachuma means local water purveyors — primarily those on the county’s South Coast, including the city of Santa Barbara and the Goleta Water District — will be receiving their entire allocations of lake water this year.

It also provides a significant buffer for the future, after years of increasing concern about the persistent drought that has gripped the Central Coast region and the state as a whole.

According to the U.S. Drought Monitor map, Santa Barbara County, like virtually the entire state of California, is currently experiencing no drought impacts.

This year’s heavy rains, coming after last year’s very wet winter, are also good news for local groundwater basins, which have been drawn down by years of drought.

“Consecutive wet years are extremely important for groundwater basins,” Young said, noting that they take longer than reservoirs to refill and recharge.

“It’s extremely beneficial.”