Central Coast lake spills for first time in 12 years. It’s now at 99.7% of capacity

Water was spilling over Bradbury Dam at Lake Cachuma on Wednesday, for the first time in a dozen years.

The flow down the spillway is the most obvious sign of the huge transformation that has taken place at a reservoir that two months ago was less than a third full.

The U.S. Bureau of Reclamation, which operates the lake and dam, said in a tweet that the water releases into the Santa Ynez River were being done “to allow for incoming flows.”

Two of the dam’s four gates were opened to let water out of the lake, which is within inches of being full.

Maximum flow from the releases, which were scheduled from 10 a.m. to 4 p.m., was 4,100 cubic feet per second, according to the Bureau of Reclamation.

The bureau in recent days has been releasing water from Lake Cachuma through an outlet at the base of the dam, but this is the first time the reservoir has spilled since 2011.

Cachuma, which was 99.7% full Wednesday afternoon, is a major water source for Santa Barbara County, mainly South Coast communities including Santa Barbara, Goleta, Montecito and Carpinteria.

“The Bureau of Reclamation essentially is testing their gates as part of their standard operating procedures,” Lael Wageneck, public information officer for the Santa Barbara County Public Works Department, told Noozhawk.

Rain storm lifted water levels at Lake Cachuma

Runoff from the major rain storm that slammed the county on Jan. 9 pushed Cachuma’s level up 36 feet in just over a day, while the level overall has risen more than 60 feet.

With the lake now essentially full, water purveyors that get part of their supply from Cachuma are expected to get their full allocations this year.

The full reservoir also means that the county — which, like most of California and the West, has been enduring a multi-year drought — now has several years of reliable water supply to buffer against future drought shortages.

For the latest updates on Lake Cachuma, go to rain.cosbpw.net.

Lake Nacimiento sees major gains after storm

Lake Cachuma wasn’t the only Central Coast lake to see major gains following heavy rainfall.

Lake Nacimiento in the northern reaches of San Luis Obispo County gained more than 89 billion gallons since Dec. 1, lifting the water level more than 76 feet, according to data from the Monterey County Water Resources Agency.

On Dec. 1, the lake held 60,285 acre-feet of water.

By Jan. 11, Lake Nacimiento had risen to 275,060 acre-feet. The water has continued to stream into the reservoir, and by Jan. 17 it hit a high of 334,235 acre-feet, according to Monterey County. One acre-foot of water is equal to 325,851 gallons.

That was an increase of more than 450% in about six weeks.

As of Jan. 17, Lake Nacimiento’s surface area covered more than 5,200 acres, and it was at about 87% capacity, according to the county’s data.

On Jan. 13, Monterey County officials began carefully releasing water from the reservoir into the Salinas River to prevent the lake from overflowing. Lake Nacimiento spills when it hits 377,900 acre-feet.

As of Feb. 5, the lake was being held at about 86% capacity with 324,000 acre-feet of water within its banks and 350 cubic feet of water being released per second into the Salinas River, according to the county’s data.

This story was originally published February 9, 2023 at 1:47 PM.