Mokelumne salmon set record return

Salmon are jumping and records are breaking at EBMUD’s Mokelumne River Hatchery at the base of Camanche Dam. This year’s fall run of spawning Chinook salmon crossed the 20,000 mark for the first time since data collection began on the Mokelumne in 1940, surpassing the previous record of 19,962 set in 2017.

The Mokelumne is EBMUD’s primary water source, and protecting the river’s health is key to responsibly managing the natural resources with which we are entrusted. Our salmon program, focused on both natural reproduction and hatchery fish, is designed to make up for damming the river and impeding fish access to historical spawning grounds farther upstream.

Salmon returns are counted every year during the fall spawning season, with the bulk of the action occurring from mid-October through December. Chinook return to their home waters to reproduce after spending two to five years maturing in the Pacific Ocean. This season’s Mokelumne numbers have been off the charts. On October 29 alone we tallied the passage of 1,941 salmon, the largest one-day fish count in at least 30 years.

EBMUD Manager of Fisheries and Wildlife Michelle Workman says our robust programs are showing great results: “We have worked for decades to improve the Mokelumne’s natural habitat, strategically manage pulse flows from Camanche Reservoir, fertilize and incubate additional salmon eggs in partnership with the California Department of Fish and Wildlife at the hatchery, and protect the river’s ecological health.”

A cancelled commercial salmon fishing season, declared to take pressure off California’s stressed Chinook population, also boosted this year’s numbers. But EBMUD’s work still stands out as returns on other Central Valley rivers continue to struggle. Though the Mokelumne only contributes about three percent of the freshwater flow into the Sacramento-San Joaquin Delta, its thriving salmon population makes up roughly 50 percent of the commercial catch off the coast of California. That’s a statistic we share with pride. Learn more about EBMUD’s work on the Mokelumne River at