Officials reviewing options for Nimbus Hatchery fish passage
In 1955 the U.S. Bureau of Reclamation built the Nimbus Fish Hatchery at Gold River to mitigate the loss of spawning habitat for Chinook salmon and steelhead trout caused by construction of the Nimbus Dam. The hatchery is located on the south bank of the American River one-quarter mile downstream from Nimbus Dam.
The river near the hatchery has become increasingly popular for fishing and water recreation. It is next to the American River Parkway, providing a perfect rest stop for bicyclists and walkers.
Nimbus Fish Hatchery houses egg incubators and fish-rearing troughs. The eggs are raised in 12 ponds and hatch in 50 to 60 days. Around 4 million 6-month-old salmon, 4 to 5 inches long, are trucked and planted in the Delta estuary annually. Steelhead are usually planted as yearlings in January or February in the Sacramento River near Rio Vista.
The California Department of Fish and Game operates and maintains the hatchery. A weir spans the river next to the hatchery. The weir stops the upstream migration of fish and guides them to the entrance of the fish ladder. Salmon and steelhead jump over 20 steps to the top of the fish ladder; from there, the fish swim into a holding pond.
The aging weir is susceptible to damage from high water flows and requires annual flow reductions to conduct maintenance.
The U.S. Bureau of Reclamation and California Department of Fish and Game have formed a joint Nimbus Hatchery Fish Passage Project. The project is designed to accomplish four goals: 1) meet hatchery mitigation goals; 2) address damage and deterioration of the weir structure; 3) reduce operational impacts to sensitive species; 4) address worker and public safety concerns.
The project is in the public comment phase of the Environmental Impact Report/Environmental Impact Statement.
Four alternatives are under consideration:
- Alternative 1A calls for removal of the weir, modifying the fishway, and closing fishing within 250 feet of the new fishway structure.
- Alternative 1C calls for removal of the weir, modifying the fishway, and closing fishing from Nimbus Dam to the USGS cable downstream from the weir.
- Alternative 2 would replace the existing diversion weir.
- The No Action Alternative would continue existing conditions.
The Bureau is also considering three visitor management options for Nimbus Shoals, east of Hazel Avenue just below Nimbus Dam. The public access options can mix and match with the fish passage options.
Currently, visitors can walk or drive to Nimbus Shoals from 6 a.m. to 9 p.m. in the summer and from 7 a.m. to 7 p.m. in the winter. The options are:
- Public vehicle access with defined parking
- Walk-in only access
- No public access.
More information is on the Bureau’s website at www.usbr.gov/mp/ccao/hatchery.
Written comments from the public will be accepted until close of business on Tuesday, Nov. 30. Send comments to David Robinson, Bureau of Reclamation, Central California Area Office, 7794 Folsom Dam Road, Folsom, CA 95630, or e-mail to [email protected], or fax to (916) 989-7208.