Lewiston, Ca. – The in-river work period begins on July 15 for the restoration project at Sawmill. Crews will be focused on access, wood instillation, excavation and fill.
During rehabilitation, the river does experience short-term impacts. To mitigate impacts to salmon and other wildlife, the Program and contractors implement mitigations to monitor and minimize those effects. These mitigations include:
- Excavators that work in the river use vegetable oil based hydraulic fluid, and all vehicles are inspected for leaks before entering the river.
- Turbidity is monitored to stay below certain thresholds known to be sustainable for fish populations. If exceedance happens (which typically still remains under the sustainable threshold), work stops until readings reduce.
- In-river work is done when there are fewer fish in the river and is performed prior to typical spawning times.
- Work sometimes extends into the beginning of the spawning season. If that occurs, additional conservation measures are triggered. For example, river crossings are covered with materials that prevent fish from building redds in them, and monitors check for spawning fish in the vicinity of the crossing.
Proposed Project Timeline
Rehabilitation to improve rearing habitat for young salmon and steelhead began June 22. Work includes reshaping floodplain surfaces, addressing the long-term processing area and, staging material for future restoration efforts. Neighbors may notice temporary truck traffic and construction noise during work hours.
Disturbances will be limited to active construction periods, Mon.– Fri., 7a.m. to 7p.m. Crews are authorized to work on Saturdays, but are as necessary and Saturday work will likely be infrequent.
Implementation Dates: June through mid-October. Please contact us with any questions: (530) 623-1800
Public Scoping: December 4, 2023 – December 17, 2023 (complete)
Draft EA for Public Comment (30 day period): May 2 – May 31, 2024 (complete)
Final EA and Decision: July 24, 2024 (complete)
Proposed Implementation: Summer 2025 – Fall 2026
Project Summary
Located in Lewiston between river miles 108 and 110 is the location of the proposed Sawmill Gravel Processing Site Rehabilitation Project. The proposed project area boundary encompasses 75.5 acres of land, of which 62.5 are controlled by the Bureau of Land Management, six acres owned by the State of California, and the remaining seven acres are comprised of nine private parcels. This location was the site of a previous rehabilitation project in 2009 and has continued to be utilized as a sediment processing site for the Program due to its large supply of dredger tailings. Sediment processed at this site is used for channel rehabilitation and sediment augmentation.
By 2019 many of the site’s tailings piles have largely been processed down to a point that the surfaces could potentially be reconnected to the river. The major access routes for the project site will be Rush Creek Rd. on river right and Goose Ranch Rd. on river left.
- The current design models an increase in fry capacity summed over the range of frequent winter flows (300 to 1,000 cfs) by 91% over existing conditions. Presmolt Capacity summed over that range of discharge is modeled to increase by 85%.
- Between the most common baseflows between 300 to 450 cfs, fry and presmolt capacity is modeled to increase by 132% and 125%, respectively
- A large proportion of the material excavated during construction of this project will be staged for future processing to produce gravel and other geologic materials needed for rehabilitation activities elsewhere along the Trinity River.
- Estimated cut volume is 94,135 yd3 and the fill volume is 95,345 yd3
The figure below shows the proposed Sawmill project activity areas.
Sawmill Project Goals and Objectives
A primary driver of rehabilitation work in the Sawmill area is the need to partially decommission a long-term gravel processing site in a way that leaves it in an ecologically beneficial state. In keeping with the general programmatic goals of the TRRP, this means that the project design should strive to:
- Increase the quality and availability of rearing habitat for juvenile salmonids over a wide range of discharges.
- Increase the extent and frequency of floodplain inundation.
- Promote fluvial processes such as cut and fill alluviation.
- Maintain and improve existing adult holding habitat, particularly at Burner Hole.
- Promote the development of healthy, diverse riparian vegetation.
- Increase the supply of large wood available to the river.
Possible Local Disturbances
- Highway-legal haul trucks would make deliveries of equipment, large wood, plants, and other needed materials during work hours using existing roads. This may cause road delays.
- Nearby residents may experience noise commensurate with the use of haul trucks and heavy construction equipment, such as bulldozers and excavators during business hours.