California reservoir race: Which reservoir filled up first?

It’s official, at least one of California’s reservoirs is now at capacity for the first time in years, according to data from the California Department of Water Resources. High reservoir levels are a welcomed relief after years of drought.

Wet weather has poured into the Golden State over the past several months, and reservoirs started to swell. The three that were poised to head over the top with a bit more moisture included San Luis, Cachuma and Castaic reservoirs. But which one took the win this week?

Cachuma Reservoir reached 100% of its capacity, or 193,305 AF, on Wednesday. AF stands for acre-feet, the measurement commonly used for water. One acre-foot equals about 326,000 gallons, according to the Water Education Foundation.

Cachuma is located on the Santa Ynez River, 25 miles northwest of the city of Santa Barbara. Water in this reservoir is also sent through the Santa Ynez mountains to supply residents in the South Coast region, including Montecito, Summerland and Carpinteria.

San Luis Reservoir has been sitting at the 99% of capacity mark for weeks. The quick growth of the reservoir over the past several months made it seem a likely winner in the reservoir race.

Castaic Reservoir in Southern California has been hovering around 95% to 96% of its capacity for the past two weeks. Castaic is about 45 miles outside of Los Angeles, and it provided water to more than 4.8 million Californians in 2021 alone.

DWR has been maintaining scheduled releases from Lake Oroville into the Feather River for fish planting operations. This caused the Feather River to swell for a period, but the levels quickly returned to normal. The Oroville reservoir water levels has been steady at an 85-89% capacity with the releases.

The wet weather has certainly benefitted the state, as some areas have climbed out of the drought. However, the rain and storms have also had challenging impacts including flooding, downed trees and even feet of heavy snow in mountainous areas. As the now record-breaking snowpack begins to melt with warmer temperatures, many in Central California could be at risk from further flooding.