Lake Nacimiento in the northern reaches of San Luis Obispo County has seen its banks nearly burst from the winter rainstorms.
The lake gained more than 89 billion gallons since Dec. 1, 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 recent high of 334,235 acre-feet, according to Monterey County. One acre-foot of water is equal to 325,851 gallons.
That’s 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.
The huge gains caused the reservoir’s water level to rise more than 76 feet from Dec. 1, burying shorelines that had long been uncovered during the drought. The rainstorms also ripped some docks away from shore and caused lots of debris to flow into the lake.
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.
“It is healthy for the system to release small amounts of water now, versus waiting and having to release larger amounts of water later,” said Monterey County District 3 Supervisor Chris Lopez in a news release on Jan. 13.
The lake is now 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.
“We want to conserve as much water as possible but still leave room for any upcoming rain events, which usually go into March,” wrote Monterey County communications coordinator Maia Carroll in an email to The Tribune.