SACRAMENTO REGION, CA (MPG) - Beginning next month, parts of the American River will change to benefit salmon and steelhead migration.

Sacramento Water Forum programs will add nearly 42,000 cubic yards of gravel to Lower Sailor Bar and Nimbus Basin. The projects – continuing habitat restoration undertaken by the agency since 2008 – are geared to improve breeding opportunity for diminished chinook salmon and steelhead populations.

Man-made river alterations have threatened these species since gold rush excavations. More recently, Folsom and Nimbus dams blocked spawning paths; dams also barred natural gravel movement to lower river reaches.

“Some salmon and steelhead return to their home water and can’t find a place to spawn,” explained Water Forum Habitat Manager Erica Bishop. “Though the Nimbus Hatchery has a role in juvenile fish production, the Water Forum’s focus is to help salmonids complete life cycles naturally.

“Steelhead and salmon once had 200 miles of the American River watershed for spawning as they returned from the ocean,” Bishop noted. “We’ve limited this to about 12 miles. Fish can’t build nests among boulders. They need moveable gravel to make their redds (nests). The lower American River is gravel starved. We need to do everything we can to allow these fish to maintain their species.”

Lower Sailor Bar work begins August 1; the Nimbus Basin project starts August 27. In preparation, tons of Lake Natoma stones have been graded to suitable size. This gravel will be trucked to Nimbus and Sailor Bar for redistribution.

Habitat restoration includes nursery inlets to accommodate growing juvenile fish before their migration to the Pacific Ocean. Planting of native vegetation around inlets will engineer shade and bring insects to feed small fry.

In a larger 2021 project, 16,000 cubic yards of gravel were bulldozed into shallows near Ancil Hoffman Park. Working against the clock, the project restored habitat for the fall salmon migration. Soon after, steelhead spawned in the same gravel beds.  

“We have a narrow work window, as specified by the Endangered Species Act,” Bishop said. “Our work is targeted over time frames least likely to affect migrating fish.”

Project success is evident. 2019 restoration above Sailor Bar resulted in 1,000 new chinook nests. The augmented Ancil Hoffman site last winter housed 30% of all American River steelhead spawning.

“Results are immediate,” Bishop noted. “We see salmon beginning to spawn as we finish our projects. We know our restored habitats work.

“Although the ongoing drought can make river conditions challenging for fish, our projects focus on long-term improvement of river health.”

Habitat restorations have been completed at River Bend Park, Sacramento Bar and in stretches of the American River along Sunrise Road. Lower Sailor Bar and Nimbus projects will wrap by early October. Though staging areas will be fenced during construction, river access and rafter use will not be restricted. In-river work will pause to enable weekend and Labor Day recreation.

Water forum projects are supported by the Bureau of Reclamation, CA Prop 68 funding, Sacramento City and County and signatory water agencies.

Learn about the water forum at www.waterforum.org.