River Riffle Newsletter – August

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River Riffle Newsletter – August

Cover photo provided by photographer Joel Patton and the 2023 Trinity River Photo Contest held last February.


  • Trinity River: Current Conditions
  • Watershed Restoration: Weaver Creek Restoration Planning Project
  • Featured Article: Temperature Ecology
  • Trinity River Watershed Plant Spotlight: California Buckeye
  • Upcoming Meetings and Events

Trinity River

Current Conditions: August

River flows continue to be released from Lewiston Dam at the summer base flow of 450 cubic feet per second. Upper and lower river temperatures have continued to trend lower than 2022 and remain “optimal” (50F-65F) for spring salmonids holding in the river. Numbers of fish trapped in the JC weir have gone on a downward trend indicating that spring run steelhead and salmon are working their way up river and the fall run are holding.

River enthusiasts will see a rise in flows due to tribal trust agreements between the Hoopa Valley Tribe and the Bureau of Reclamation. Beginning Aug. 18 flows will gradually increase from the summer base flow of 450 cfs and are expected to reach a peak flow of 2,000 cfs on Aug. 20 before gradually returning to summer base flows later in the week. The Bureau’s official press release ….

Photo: Trinity River in the Hoopa Valley August 11, 2023 [Kiana Abel, Reclamation/TRRP]

Watershed Restoration

Weaver Creek Restoration Planning Project

Weaver Creek is recognized in the CA Coho Recovery Strategy for California Coho Salmon (CDFGW, 2004) as being among the highest priority watersheds for restoration in California. The federal SONCC Coho Recovery Plan (NMFS 2014) also identifies Weaver Creek, and several of its tributaries, as having some of the highest potential for coho salmon habitat within the upper Trinity River basin.

Partially funded by the Restoration Program through our watershed grantee program, the Weaver Creek Restoration Planning Project is to complete project design to address degraded stream conditions and complete the environmental compliance process for a fish habitat restoration project on Weaver Creek. The Weaver Creek Restoration Project represents an initial effort to begin development of a fish habitat enhancement effort on Weaver Creek and its two primary tributaries, West Weaver and East Weaver Creeks. 

The general process of project development includes the following steps for the grantees; Nor Rel Muk Wintu Nation, Yurok Tribal Fisheries Department and Trinity County’s Environmental Department:

  • Collect existing conditions data for the project study area
  • Perform technical modeling for existing site conditions
  • Develop a draft project design for the project area
  • Complete a 30%, 60%, and 90% design report for the project
  • Complete the NEPA, CEQA, and local environmental planning processes for the project
  • Conduct public outreach for the project
  • Obtain environmental permits for the project

The grantees also plan to present the project to the Trinity River Watershed Council, Weaverville Sewer District, and the Weaverville Community Forest Steering Committee. For more information please contact, Patrick Flynn, Environmental Compliance Specialist at pflynn@trinitycounty.org or by calling 530-623-1351.

Featured Article

Thermal Ecology of the Trinity River

Temperature is one of the most important environmental influences on salmon biology (Carter 2008). Temperature influences growth, migration, spawning, disease and the availability of food and affects salmonids differently by system, season and life stage. Over the years, messaging and management focused on the benefits of cold waters, because it was widely thought to be true that cooler temperatures did not harm salmon. However, we are witnessing a paradigm shift, especially with the emergence of new studies regarding temperature needs of young Trinity River fish in the height of their growth stage while migrating to the ocean.

Photo provided by: Aaron Martin, YTFD

Trinity River Watershed: Plant Spotlight

California Buckeye

(Aesculus californica)

California buckeye (Aesculus californica) is a fast-growing species that grows below 4000 feet in dry slopes, canyons, and stream edges. Various species of buckeye grow throughout the world, but this is the only species that grows in California. Here in Trinity County, it seems to prefer the cooler and wetter parts of the region, mostly growing downriver towards Willow Creek or along moist riverbanks.

In the Hupa language, the word for buckeye is la:whe’, and the seeds are believed to be a food of the pre-human immortals (k’ixinay). With significant preparation (including repetitive leaching, boiling, and pounding), the seeds become edible as flour or meal, similarly to acorns.

Upcoming Meetings and Events

For a full list of events, click to view the TRRP Calendar.


August 16, 4-7pm – Weaverville Farmers Market

We’ll have a booth at the Weaverville Farmers Market on August 16. Come see us, sign up for our outreach opportunities and ask us questions about restoration activities.

August 18 – Hoopa Ceremonial Flows

The Hoopa Valley Tribe has requested the Bureau of Reclamation to increase releases from Lewiston Dam to the Trinity River in support of the Tribe’s biennial Boat Dance Ceremony in late August, 2023.

Beginning in the evening of Aug. 18, Lewiston Dam releases are scheduled to gradually increase from the summer base flow of 450 cubic feet per second and are expected to reach a peak flow of 2,000 cfs on Aug. 20 before gradually returning to summer base flows later in the week.

The ceremonial flows are separate from the Trinity River restoration flows. To watch an ABC10 video about the biennial Hoopa Ceremonial Dances please click here.

August 23, 6pm – Science on the River

Lewiston Dance Hall

This month, we are taking Science on Tap ON THE ROAD!! Join us August 23 for Science on the River in Lewiston at the Lewiston Hotel Bar and Grill. Our speaker for the evening is John H. Bair, Senior Riparian Ecologist at McBain Associates-Applied River Sciences, who will present on “Rehabilitating Riparian Vegetation in the Upper Trinity River.” With 30 years of experience improving riparian function, John’s presentation will delve into the background, past, and current riparian vegetation restoration techniques used on the Trinity River, highlighting what has proven effective and the lessons we’ve learned.

Science on the River Photo

September 6 @ 6pm – Science on the River

Indian Creek Lodge – 59741 Hwy 299 West

Winter Flow Variability – What we’ve learned about the influence of flow on river ecology

Join Trinity River Restoration Program’s Flow Work Group Coordinator Ken Lindke, CDFW, for a presentation covering flow management, past and present. The presentation will cover a history of flow management, preliminary results from Water Year (WY) ’23 and recommendations for WY’24. The event will be held outdoors at the Indian Creek Lodge in Douglas City. Seating will be limited so please bring a lawn chair or blanket. Refreshments will be available for purchase during the event.

Photo provided by: Aaron Martin, YTFD


September 9, 9am Trinity River Clean up

Join your Trinity County neighbors for a day of removing waste from the Wild and Scenic Trinity River, recreation areas, and tributaries!


September 12, 1pm-3pm – WIIN Act Quarterly Update Meeting

Virtual: Teams meeting call-in info TBD

Reclamation’s Bay Delta Office will hold a quarterly meeting to provide an update on the development of the Biological Assessment for the 2021 Reinitiation of Consultation on the Long-Term Operation of the Central Valley Project and State Water Project, pursuant to the Water Infrastructure Improvements for the Nation (WIIN) Act. The meeting will be held virtually on Microsoft Teams.

TMC Partnership Ring

September 13-14, All Day – Quarterly TMC Meeting

In Person: Weitchpec, CA Virtual: Teams meeting call-in info TBD

Contact Us

Call Us: 530-623-1800 Email Us: info@trrp.net