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Ecosystem restoration and habitat improvement
The Folsom Dam Raise Project includes ecosystem restoration and habitat improvements. The Lower American River flood plain has significant natural ecosystem assets that have become increasingly valued in California. The ecosystem restoration feature of the Folsom Dam Raise provides opportunities to improve riparian woodlands, wetlands, and flood plain grasslands along the Lower American River. Ecosystem restoration involves planting native riparian, upland, wetland, and woodland vegetation; terracing riverbanks; and controlling non-native plants at two sites totaling about 620 acres.

Habitat improvement involves mechanization of the temperature control shutters at Folsom Dam to better control the water temperature in the river for salmon and steelhead.

Woodlake Restoration Site
The Woodlake site consists of 283 acres of previously-farmed land located adjacent to the American River and down river from the Cal Expo facilities. The restoration efforts will reconnect the river to the historic floodplain, and re-establish various riverine habitats through exotic species control and revegetation. These habitats will include riparian forest, oak woodlands and savanna, and grassland areas.

Bushy Lake Restoration Site
The The Bushy Lake site is located between the Cal Expo facilities and the American River, and consists of 337 acres of mixed vegetation and habitats. The restoration plan will connect the river to the existing Bushy Lake and create additional wetlands, floodplain areas, drainage channels, and water control and delivery structures. Valued habitats will be re-established by controlling exotic species and planting and managing native vegetation for riparian forest, wetlands, oak woodland and savanna, and grasslands.

Automated temperature shutters
Construction of Folsom Dam restricted salmon and steelhead to the 23-mile Lower American River. Recent biological monitoring indicates that water temperatures in the Lower American River tend to exceed the temperatures necessary to sustain the existing salmon and steelhead populations. Maintenance of optimal water temperatures for spawning and rearing depends on the ability of dam operators to deliver
cold-water releases to the Lower American River at critical times of the year.

Currently, dam operators must adjust the temperature shutters manually. This manual operation does not allow for the flexibility and timeliness needed to optimize the coldwater releases. Automating the temperature shutters will reduce this problem by allowing for the greatest flexibility and responsiveness to the fishery needs year-round.



Dam raise reduces flood risk

Enlarger L. L. Anderson Dam Spillway

Mooney Ridge infrequent inundation

One project element of the Raise Project is to modify the temperature control shutters at Folsom Dam. Through physical and operational improvements, flood control capacity would be increased in Folsom Lake. In addition, the temperature control shutters would be reconfigured and mechanized to improve water temperature regulation, a critical factor in the survival of fall-run Chinook salmon and Central Valley steelhead.

Fall-run Chinook Salmon
Oncorhynchus tschawytscha
Status: Federal Candidate
Habitat: Suitable water temperature, water quality, flow, and substrate needed for successful spawning and incubation.
Behavior: Spawns in upper 8 miles of American River below Nimbus Dam. Juveniles emigrate as fry and return as adults.

Central Valley Steelhead
Oncorhynchus tschawytscha
Status: Federal Threatened; California Species of Special Concern
Habitat: Suitable water temperature, water quality, flow, and substrate needed for successful spawning and incubation.
Behavior: Spawns in American River above River Mile 16. Young typically emigrate to ocean after first year. Some adults may spawn several times.