Hallwood Floodplain and Side Channel Restoration Project - Snorkel Surveys on the Yuba River in Yuba County, 2014-2025

Cramer Fish Sciences (CFS), Verdantas, 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) and Yuba Water Agency, teamed to plan, design, monitor, and 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 enhanced 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 focused 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 included 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. The purpose of snorkel surveys was to document changes in juvenile salmonid densities and fish communities before and after restoration in restored and unrestored reaches. This dataset includes snorkel survey data collected between 2014 – 2025.