Lower Yuba River Hallwood floodplain and side channel restoration snorkel surveys at the project and control reaches

Cramer Fish Sciences (CFS), cbec, inc. ecoengineering, and South
Yuba River Citizen’s League, funded and directed by the United
States Fish and Wildlife Service’s Anadromous Fish Restoration
Program (USFWS AFRP), teamed to plan, design, monitor, perform
regulatory compliance for the Hallwood Side Channel and Floodplain
Restoration Project (Project) on the Yuba River, California. The
Project is designed to restore and enhance ecosystem processes, with
a primary focus on improving productive juvenile salmonid rearing
habitat to increase natural production of fall and spring-run
Chinook Salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss)
in the Yuba River. The Project would enhance and/or create up to 157
acres of seasonally inundated riparian floodplain habitats, 1.7
miles of perennial side and alcove channels, and more than 6.1 miles
of seasonal side channels. The design approach focuses on removing
unnatural constraints (such as a mid-river training wall and very
coarse surface materials left from mining activities) in order to
allow natural river and floodplain processes to function.
Construction planning efforts include multi-year phasing to remove
about 3.2 million cubic yards of material from the site while
optimizing habitat establishment in early years and minimizing
disturbance to existing high quality riparian and aquatic habitat.  The Project included a robust monitoring program that measured the
effect of restoration on a range of ecological parameters thought to
influence salmonid habitat use and productivity and riparian
ecosystem function using a Before-After-Control-Impact study
framework. Specifically, we monitored salmonid and non-native
predator density, juvenile salmonid growth and residence time,
predation, invertebrate prey (drift) density and biomass, and
changes in acreage of a range of habitat types, including
terrestrial and aquatic vegetation. We also examined factors
influencing natural riparian tree recruitment following restoration.