This ongoing program was created to address habitat reduction and fisheries decline in the lower American River and fosters the design and installation of at least one salmonid habitat enhancement project annually. Program objectives consist of increasing the quantity and quality of spawning and juvenile rearing habitat for fall-run Chinook salmon (Oncorhynchus tshawytscha) and Central Valley Steelhead (O. mykiss). This ongoing effort is made possible by continued collaboration between the Water Forum, the U.S. Bureau of Reclamation, and the U.S. Fish & Wildlife Service (as part of their Central Valley Project Improvement Act Habitat Restoration Grant Program). Since its inception in 2010, this program has created more than 30 acres of spawning beds, 1.2 miles of side channels, and has placed 92,000 cubic yards of spawning gravel. Verdantas has provided planning, design, and construction monitoring for the program, resulting in 14 completed projects at eight sites. The latest constructed site, located at River Bend Park, was constructed in the fall of 2024, with designs in progress for an additional seven projects to be constructed over the next five years.
Past projects have included the placement of designed gravel features (i.e., spawning riffles, islands and bars), in-stream habitat features (i.e., boulder clusters and large wood installations), side channel creation, and in-channel material placement to increase the inundation frequency of existing side channels. To optimize habitat enhancement opportunities, multiple complementary elements are often used in combination for any given project. To support both design and post-project assessment, Verdantas provides physical monitoring services (including topographic and bathymetric surveys, installation and maintenance of continuous water surface elevation instrumentation, and velocity measurements via acoustic Doppler current profiler), two-dimensional numerical hydraulic modeling and habitat suitability modeling, and preparation of construction plan sets. Verdantas also participates in a multi-stakeholder technical advisory panel to develop the structure of the ongoing monitoring and adaptive management process.
Post-project monitoring has documented the incredible success of this effort with high spawning and rearing activity occurring after construction. At many sites little to no spawning or rearing activity was observed for several years prior to implementation. In general, annual utilization varies, but up to 40% of the total redds documented in a single year have been located in these project sites. To illustrate the success of the projects, in the following fall-run spawning season at the Upper Sailor Bar site, 1,614 redds (salmon "nests") were observed, as opposed to 0 the year before.
Solution
River and Flow-Related Solutions
Expertise
Natural Resources & Environmental Planning
Hydrology, Hydraulics, & Fluids
Market
Client
Water Forum
Location
Sacramento County, CA