The Trinity River Restoration Program is working on two Trinity River channel rehabilitation projects in 2025; Phase II of the Upper Conner Creek Rehabilitation Project located in Junction City, CA and Phase I of the Sawmill Gravel Processing Site Rehabilitation Project located in Lewiston, CA.

Upper Conner Creek – Phase II

Sawmill Gravel Processing Site

Environmental Assessments

The Trinity River Restoration Program’s Sediment and Wood Augmentation Environmental Assessment is complete. In addition to multiple existing sites and based on site-specific annual recommendations from the The Trinity River Restoration Program’s Physical Workgroup and Riparian and Aquatic Workgroup, the Environmental Assessment establishes new augmentation sites and allows for sediment and wood placement to address the a shortage of those key ingredients of riverine habitat upstream of Indian Creek. 

The new augmentation sites are in the upper reaches of the Trinity River downstream of Lewiston Dam and include Dark Gulch, Trinity House Gulch, Steel Bridge, and Vitzthum Gulch. River corridors which periodically mobilize sediment and large wood perform diverse physical and ecological functions. Contributions to the disturbance regime disperse organisms and provide refugia during baseflow periods and during floodplain inundation events. The Sediment and Wood Augmentation Environmental Assessment is available by clicking below.

In partnership with the US Forest Service’s Shasta-Trinity National Forest and BLM’s Redding Field Office, TRRP is finalizing a Programmatic Environmental Assessment (PEA) to evaluate aquatic habitat restoration activities in the Trinity River watershed. The Watershed PEA analysis will focus on restoration activities that improve the quality and quantity of accessible cold-water aquatic habitat. As a programmatic analysis, watershed restoration projects would be implemented within the Trinity River watershed, in Trinity and Humboldt counties, with site specific surveys and compliance for individual projects tiered to the PEA.

Watershed Grantees

In 2025, the following watershed projects are slated to be implemented.

Salt Creek Floodplain Restoration – The Watershed Research and Training Center

This project aims to improve 2,000 feet of heavily degraded salmonid habitat along Salt Creek, a South Fork Trinity River tributary, by reconnecting the creek to its historic floodplain using engineered and process-based restoration techniques. The project will increase aquifer recharge and storage for slow release to temper a thermal barrier for salmonids, restore geomorphic functions that will improve salmonid spawning gravels, create pools for summer cool water refugia, increase habitat heterogeneity for winter flow high-velocity refugia, and improve native riparian flora, all of which will increase the resilience of aquatic species from the impacts of climate change. Implementation is scheduled for summer 2025 and summer 2026

Upper Hayfork Creek Assessment and Planning Study – The Watershed Research and Training Center

This project will assess over 17 stream miles and 700 floodplain acres within the upper Hayfork Creek watershed, a major tributary to the South Fork Trinity River, to identify restoration opportunities to improve salmonid habitat quality and quantity. The project
will utilize GIS and LiDAR analyses, field measurements of salmonid presence and habitat characterization, and a comparison of ecological flow needs with water availability to produce one Restoration Assessment and Planning document with a priority list of restoration projects and one restoration design to advance toward implementation.

Water Resiliency in the Greater River Trinity Watershed for Aquatic Ecosystem and Human Domestic Needs – The Watershed Research and Training Center

The organization is tasked to plan and implement four storage tank arrays and establish long-term forbearance agreements to reduce annual water withdrawals from key tributaries to the Trinity River during the summer low-flow period. The project will increase the quality and quantity of natural habitats crucial to the survival of anadromous fishes and aquatic organisms in the Trinity River Watershed. Implementation is scheduled for spring 2025.

Weaver Creek Habitat Restoration Implementation – The Yurok Tribe Fisheries Department

The Yurok Tribe Fisheries Department will create instream habitat and develop new floodplain areas along the upper section of Weaver Creek, a tributary to the Trinity River. The project will control the spread of invasive plant species, establish habitat connectivity during summertime baseflow conditions, and support populations of threatened Coho Salmon. The Tribe will construct new habitat features including 4.96 acres of floodplain, 1.23 acres of overflow channels, 0.94 acres of constructed riffles, 0.37 acres of channel fill, and 0.36 acres of low flow channels. These enhancements will increase the structural complexity of the project reach and mitigate the impacts of low flows, which can lead to dry channel conditions on Weaver Creek. The project area is identified in the state and Federal recovery plans for Coho Salmon, which encourage floodplain reconnection and streambed restoration in Weaver Creek. The Yurok Tribe is collaborating with the Nor Rel Muk Wintu Nation, Federal land managers, the Weaverville Sanitary District, and adjacent landowners for this restoration project. Implementation is may be implemented as soon as summer 2025.

The Upper Conner Creek Rehabilitation Project is set to mobilize Phase 1 construction early next week. The site is located approximately one river mile downstream from the Dutch Creek Bridge in Junction City. After mobilization, phase 1 rehab will focus primarily on the upstream portion of the area and consists of lowering the riparian floodplain, adding riffle enhancements, placing large wood to slow water and create habitat and planting of riparian vegetation. Crews began mobilizing equipment and staging areas Monday.

The largest feature of this portion is the R1 floodplain.  This 5.7 acre broadly lowered surface and pilot channel on river left targets inundation at levels from 500 to 3,500 cfs.  Given that this reach of the Trinity’s average winter flow is 771 cfs, this feature should remain wetted for much of the fall winter and spring, providing low velocity salmonid refugia and opportunity for riparian recruitment.   

Supporting this floodplain/pilot channel feature, phase 1 will also see the construction of a riffle (IC-1 ) and the structured log jam (SLJ-1). The riffle (IC-1) is a 160ft long riffle that will raise the water surface elevation to encourage flows onto the new floodplain feature and has the added benefit of providing habitat for benthic macroinvertebrates, which are an important food source for salmonids.  In between the main stem Trinity and the new pilot channel is a placed log jam (SLJ-1) which primary purpose is to provide temporary protection to the pilot channel, until riparian vegetation has an opportunity to establish.  It is expected that this feature will eventually succumb to the forces of the river, but will provide low velocity salmonid refugia along the channel margins until then.  Once revegetation commences this fall, the construction area will receive a compliment of cottonwoods, mixed willows, and a variety of sedges and rushes.  The revegetation effort improves the aquatic habitat, helps prevent less desirable plants from taking hold, and generally speeds the healing of the river. 

Junction City residents should expect to see increased traffic and activity along Red Hill Rd in the vicinity of the Smith Pit.  Hours of operation on site are from 7am to 7pm, Monday thru Friday (with an allowance for Saturday if deemed necessary).  Civil construction and revegetation of phase 1 should be completed by years end.   

If you’d like to read more about the Upper Conner Creek Rehabilitation Project, please click here.

While it has not been a focus of the TRRP for many years, infrastructure improvement was one of the foundational tasks that was laid out in the 2000 Trinity River Mainstem Fishery Restoration Record of Decision. Years of low, predictable flows had led riparian property owners to develop very close to the river’s edge. In order to implement restoration releases, the TRRP has worked with willing property owners to upgrade or remove infrastructure that could be damaged by restoration flow releases as guided by the “maximum fisheries flow” boundary.

The maximum fisheries flow is an 11,000 cubic feet per second release from Lewiston Dam (the highest the program can target for restoration objectives) that coincides with a major spring storm event. In the program’s first decade, there was a big push to address permitted infrastructure to clear the floodplain for fisheries releases; we moved roads, replaced several bridges, upgraded dozens of septic and water intake systems, and relocated a house in Douglas City. Another house (391 River Acres Rd in Junction City) was identified as being inside of the maximum fisheries flow boundary, but the owners were not interested in improving or selling their home at that time.

The circumstances changed in the late 2010’s when the house sold to a new owner who used it as a fishing cabin and was very interested in finding a mutual solution that would benefit Trinity River fisheries. Together with engineers and architects the landowner and TRRP explored moving the house, building a levee, and elevating the living area with a flow-through bottom story. In the end, none of those solutions proved feasible due to flood concerns with adjoining properties and other constraints. The situation led the homeowner to decide to sell the house to the Bureau of Reclamation, who acquired the property in 2023.

In March of 2024, Cal Inc., a certified small business located in Vacaville, California was awarded the contract to demolish the 391 River Acres structures. Cal, Inc., specializes in general construction, abatement and remediation services, and environmental and safety training, and it took their professional staff only a few weeks to gather intel, test for lead and asbestos, and mobilize machinery, crew and subcontractors to begin the demolition.

Over the course of the week many of the neighbors wandered over and reminisced about those who had called the River Acres house home (or home away from home) over the years.  They were understandably sad about losing a piece of River Acres history but were excited about the open space for their dogs and grandchildren to run and play in. We appreciate their tolerance of the noise, construction and extra visits these past few months. The project will be considered complete once the bare areas have been mulched and seeded, likely to be fully complete by the first of May.