Eel River Dams License Surrender

Federal Energy Regulatory Commission
(Eel River Dams, called the Potter Valley Project is docket #P-77)
PG&E’s Potter Valley Project

Congressman Huffman’s Ad Hoc Committee.

Friends of the Eel River has been a participant in Congressman Huffman’s collaborative Ad Hoc process, helping develop locally supported recommendations for the Federal Energy Regulatory Commission.

Reasons to Remove the Eel River Dams

The Eel River is home to many wonderful flora and fauna, including three salmonid species listed under the federal and state Endangered Species Acts; California Coastal Chinook, Southern Oregon Northern California Coho, and Northern California Steelhead.
UPDATE: Read Friends of the Eel River's Sept 2018 press release about the results of geotechnical analysis conducted by Miller Pacific Engineering Group. Press release and accompanying technical memo here.

Miller Pacific engineers concluded “it is our professional opinion that the large landslide complex adjacent to, and possibly below, the left abutment presents a significant geological hazard to the dam that requires further investigation. Since the dam acts as a strut across the Eel River, the landslide mass may be applying a significant soil pressure to the dam. In addition, the preliminary calculated seismic displacements are enough to cause concern about uplift or damage to the dam from landslide movement during a strong seismic event.”
The original plan called for Scott Dam to be constructed in a straight line across the Eel River canyon, and to attach to a substantial rock outcropping on the south side of the canyon, originally believed to be bedrock. During construction, however, this feature, now called ‘the Knocker,’ began to move, revealing that it is in fact a very large boulder, and not bedrock at all (see these photos from 1920 that show 'the knocker' before and after it slid down). The design of the dam was changed to run in front of ‘the Knocker,’ as it does today. In the photo below, the 'the Knocker' is the purple blob directly behind the dam. Many dams are built on or nearly on fault lines because that's where a river channel is naturally most narrow. Scott dam is no exception. The image below is a geologic map of Gravelly Valley, where Scott Dam is located. Click here to read PG&E's entire report on geology and seismicity.
While there is no longer commercial fishing on the Eel River, salmon and steelhead from the Eel are a part of the commercial ocean fishery. Protecting these fish protects local economy.

Click here to read the Center for Environmental Economic Development's 2004 study, Economic Benefits to Mendocino and Lake Counties from Removing the Dams on the Eel River. Study authors Dr. Ihara and Marshall conclude that "nature-based tourism benefits to Mendocino and Lake Counties, counting both rafting and increased fishing, are estimated to exceed $2,000,000 annually".
The Eel River Dams generate very little energy. Their maximum generating capacity is 9.4 megawatts, but according to analysis by Dr. Rosenblum, the hydropower facility has operated at a maximum of 50% capacity over the last decade.

Click here to see Dr. Rosenblum's presentation that includes analysis of hydropower generation at the Eel River Dams (Potter Valley Project) and Coyote Dam in Mendocino, as well as analysis of replacing that energy with solar power. A five acre solar array would more than replace the energy generated by the Eel River Dams.


Potter Valley Project Studies

This paper by Alyssa FitzGerald, et al from National Marine Fisheries Service confirms previous research and traditional ecological knowledge that the upper basin habitat behind Scott dam is some of the best in the entire watershed. The habitat is notable for its cold water availability, even in the summer months of a dry year, and the physical characteristics that make it especially productive spawning and rearing habitat.

Click here to read the full paper.

This paper by Samantha Kannry, et al from UC Davis presents evidence that alleles for both anadromy and pre-mature migration (summer-run timing) are present in rainbow trout trapped in the upper basin behind Scott dam. It also documents the populations of Northern California summer steelhead elsewhere in the Eel watershed, in the north and middle forks, as well as the Van Duzen river.

Click here to read the paper.

Geosyntec conducted an assessment of sediments in Van Arsdale and Lake Pillsbury Reservoirs on behalf of the California State Coastal Commission.

This research by Emily Cooper from Humboldt State University presents estimates for potential habitat for both Chinook Salmon and steelhead trout.

"Using three fish passage scenarios, potential Chinook Salmon habitat was estimated between 89-127 km (55-79 mi) for spawning and rearing; potential steelhead trout habitat was estimated between 318-463 km (198-288 mi) for spawning and between 179-291 km (111-181 mi) for rearing."

Click here to read the paper

Click here for an interactive map of steelhead populations

Click here for additional documents and information from the Ad Hoc Committee

Pre-Application Document and Notice of Intent to file for new application
Submitted to FERC June 28, 2019

Feasibility Study Report
Submitted to FERC May 13, 2020

Mercury and Reservoirs Factsheet
September 2013