A large amount of rearing and spawning habitat was lost in areas upstream of Central Valley dams following dam construction. Large amounts of rearing side channels and floodplain habitats downstream of the dams have also been lost to dikes, levees, drainage, and conversion to agricultural lands or other development.
Soon after hatching, when flows increase, juvenile salmon often move downstream due to a lack of suitable rearing areas in the upper river. Much of the main river channel is devoid of food and shelter necessary for fry rearing; however, side channels can provide lots of both if restored to their original condition. In some cases, this is as easy as removing gravel plugs at the upstream end of the channels.
In addition to Sacramento, the Feather River has several locations where rearing side channels and floodplains can be reopened, with significant benefits for salmon in that watershed.
This project would create up to 13 new rearing side channels at multiple locations in the upper Sacramento River basin and several additional ones on the Feather River. Restored side channels on these rivers are expected to improve both growth and predation survival for both listed and non-listed salmon runs.
In addition, some historic floodplain habitat still exists, separated from the rivers by levees. Restoration of some of this is as simple as breaching the levees and allowing the lands to flood again when the rivers rise. This provides a high-quality rearing and feeding habitat for juvenile salmon.