Sediment and Wood Augmentation along the Trinity River Restoration Reach

Sediment and Wood Augmentation along the Trinity River Restoration Reach

The Proposed Action would allow for wood placement to occur at the proposed winter-spring augmentation sites and at the existing augmentation sites to enhance the efficacy of sediment augmentation activities and improve aquatic resources, during the winter-spring augmentation period, which would generally occur between December 1 and May 1, to coincide with synchronized flow releases (October 15 – February 15) and winter elevated baseflow releases (February 16 – April 15). Winter-spring augmentation activities may occur as early as November 1 during extremely wet precipitation periods. These four proposed sediment and wood augmentation sites are located within the channel rehabilitation project environmental study limits (ESLs) at Dark Gulch, Trinity House Gulch, Steel Bridge, and Vitzthum Gulch and are referred to as the proposed winter-spring augmentation sites. The proposed project is needed to enhance existing habitat and provide new salmon and steelhead spawning and rearing habitat in the Trinity River below Lewiston Dam. The purpose of the project is to add suitable-sized sediment and wood through manual augmentation at up to four new potential sites. Sediment and wood augmentation would: Provide sediment and wood to the river that would help create natural bar, riffle, and pool sequences; Promote scour and fill processes that form bars and pools in the river channel; Provide juvenile rearing habitat in the active channel, including refugia from predators, as opposed to floodplain rearing habitat that is only available during high flows; Create and maintain areas suitable for adult salmon to lay eggs (also known as spawning beds for redd construction); Increase the topographic complexity of the river channel; Increase habitat for salmon prey, including macroinvertebrates associated with in-channel wood; Address the deficit of woody material in the Trinity River, which would increase the availability of organic matter in the channel and floodplain, help to develop and support diverse habitat; and Increase total natural occurring salmon population within the targe restoration reach.

Trinity

Unincorporated

California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Northern and Eureka Region 1 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of Resources Recycling and Recovery, California Department of State Parks, Division of Boating and Waterways, California Department of Transportation, District 2 (DOT), California Department of Water Resources (DWR), California Governor's Office of Emergency Services (OES), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, North Coast Region 1 (RWQCB), California State Lands Commission (SLC), Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Division of Water Quality, State Water Resources Control Board, Division of Water Rights

Other (River restoration)

River restoration

Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cultural Resources, Energy, Geology/Soils, Greenhouse Gas Emissions, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mandatory Findings of Significance, Mineral Resources, Noise, Population/Housing, Public Services, Recreation, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Wildfire