The Sawmill Gravel Processing Site Channel Rehabilitation Project consists of a number of rehabilitation activities intended to improve salmonid habitat for all life stages by creating large areas with suitable flow depth, velocity and cover. The Sawmill rehabilitation actions would restore a dynamic floodplain and habitat while, on a smaller scale, facilitate the dynamic fluvial geomorphic processes that existed before Lewiston and Trinity dams were constructed. Project design objectives include physical, biological, and riparian outcomes. Physical (Geomorphic/Flow) - Promote dynamic fluvial river processes by removal of tailings piles from riverine valley bottom and recontouring of the river channel. Outcomes would include increased scour and deposition, lateral migration, sinuosity, and extent and frequency of floodplain inundation; Preserve alluvial potential of reach by removing and avoiding elements that restrict dynamic river processes, such as ballast material using cobble and boulders greater than 6 inches and large wood pilings; Promote fine sediment deposition on floodplain and low bench surfaces; Utilize mainstem, tributary and valley wall water sources and perched groundwater to reduce excavation and promote functional floodplains capable of natural riparian recruitment. This would benefit natural and constructed off-channel habitats; Reduce wood storage deficit by using dynamic wood structures; Reconnect and reinvigorate abandoned floodplains; and Preserve bed complexity resulting from bedrock connections. Biological - Increase and sustain fry rearing habitat area across a range of flows during January 1 – April 30; Create seasonal surface water connection to off-channel habitats. Outcomes would include increased lateral and longitudinal connectivity of fry and juvenile rearing habitat (January 1 – April 30) and pre-smolt/smolt habitat (April 1–June 30); Increase rearing habitat capacity across the range of frequent discharges during the period when juvenile salmon are present in the river (600–1,000 cubic feet per second [cfs]); Increase area of vegetated surfaces experiencing continuous inundation duration of ≥ 14 days during normal and wetter years for fry/juvenile rearing (January 1–April 30th); Increase area of vegetated surfaces experiencing continuous inundation duration of ≥ 14 days during Normal and wetter years for pre-smolt and smolt rearing (April 1st – May 31st); Enhance existing native amphibian habitat (facilitate local warming in channel margin habitats to improve existing populations and breeding use); Ensure that habitat availability continuously increases as discharge increases above baseflow; and Increase recruitment and production of spawning gravel within the aquatic ecosystem. Riparian - Preserve the matrix of existing multi-story riparian vegetation and cottonwoods within the floodplains; Increase surfaces providing greater than 21 days of moist soils within 0.85 ft of the ground surface during seed dispersal (April 1–June 30) in normal and wetter years surfaces for natural riparian regeneration, especially near local cottonwood seed sources. Surfaces meeting the flow duration criteria would inundate at flows ranging from approximately 2,200 cfs to 3,500 cfs; Revegetate constructed floodplains and benches with native woody riparian species, conifers, and understory species; Increase riparian vegetation biomass and abundance in the tree, shrub, and herb layers along design features; Increase the number of trees, especially cottonwood, which could supply logs over 24 inches in diameter to the river; and Increase native species richness and abundance.

The project involves stabilization of 190’ of Russian River bank erosion adjacent to two private residences at 15170 & 15150 Drake Rd., Guerneville. The purpose of the project is to prevent the loss of residential structures, a public sewer system operated by Sonoma Water, valuable land, and wildlife habitat. The project will reduce sedimentation into the Russian River. The project will also help to restore native vegetation to the site. Promoting the ecological integrity of the Russian river is an important project goal.
Construction is planned for summer 2025, and is expected to take approximately four weeks to complete.