Biologists Maeghen Wedgeworth (left) and Matt Ziemer join Water Forum Manager Erica Bishop and biologist Jamie Sweeney during surveys of fish-nesting habitats on the Lower American River. The survey follows recent gravel bed restoration by the Sacramento Water Forum.

SACRAMENTO, CA (MPG) - Within weeks following completion of a $1.7-million Water Forum project in October, giant Chinook were spawning in new gravel beds. The 2024 effort to aid the endangered species centered on River Bend Park (Rancho Cordova) and William B. Pond Park (Carmichael).

The work augmented salmon breeding habitat with thousands of tons of clean gravel. A deepened and reconnected side channel also created rearing havens for baby salmonids.

Following similar projects over 16 years, the latest restoration impacted eight American River acres.

At the peak of the recent salmon run, biologists counted almost 40 new redds (nests) in previously unhospitable areas. Female salmon were using muscular tails to dig cradles when this reporter joined survey biologists. Following the Chinook migration, steelhead and Pacific lamprey will reproduce in the same spots.

“Monitoring is important,” explained Kirsten Sellheim, senior scientist for Cramer Fish Sciences. “We bring what we learn into future projects. In spring, we’ll learn how juvenile fish are using new side channels.”

River Bend and William B. Pond Park are further downstream from previous Water Forum projects. Spawning areas get crowded closer to Nimbus Dam; congestion reduces embryo survival. By continuous restoration, the Water Forum has spread opportunities over many miles. Greater reproduction success seems to have resulted.

For millions of years, salmonids maintained their species unaided. The American River and its tributaries once offered 200 miles of spawning sites. Gold Rush excavation greatly altered the riverbeds. Later, dams blocked migrations and barred natural gravel movement.

“The lower part of the American River has become gravel-starved,” said Water Forum habitat manager Erica Bishop. “Some fish reach home waters and can’t find a place with the right conditions for spawning.”

Though the Nimbus Hatchery has a role in fish reproduction, the Water Forum focus is to help fish complete life cycles naturally. Habitat restoration continues federal and state-funded efforts to aid salmonids. At the end of their lifecycles, adults must have movable stones and oxygenated water for nesting.

Biologists Maeghen Wedgeworth (left) and Matt Ziemer locate and measure new Chinook nests in a reconnected back channel near River Bend.

Last summer, 6,800 cubic yards of pre-sized gravel were trucked from mine tailings at Mississippi Bar (Orangevale). The loads were bulldozed into riffles and shallows. The 2024 project also reconnected a side channel where hatchlings will feed and grow in spring.

Bulldozing wrapped just as the first Chinook reached Arden and Carmichael waters in October. Results appeared immediately. As early runners got down to business, more than 1,800 newly-planted willows and sedge plants took root. This vegetation will shelter baby fish from storms and predators. By spring, thousands of native wildflower and grass seeds will have germinated and bloomed. Small fry will feed on insects attracted by this vegetation.

A Water Forum project supported a third of in-river steelhead reproduction for the 2021 season. 

“Fish begin to spawn as soon as heavy machinery leaves the water,” said Water Forum manager Erica Bishop. “We know the habitats we create meet their needs.”

Water Forum projects are supported by the Bureau of Reclamation, U.S. Fish and Wildlife Service, Sacramento city and county and signatory water agencies. Learn about the Water Forum at www.waterforum.org.