To Dam or Un-Dam California? Now That’s a Complicated Question.

While some dams are old and nearly useless, major dams like Shasta provide flood control and water storage for millions of California residents

If you feel the need to plunge a stick into a hornets nest, try bringing up the subject of dam removal in California. Wherever you find arguments pro and con, you’re inevitably going to stumble over the oft-used quote, “Whiskey is for drinking; water is for fighting over,” often attributed to Mark Twain. The topic is so contentious that people even like to fight about the quote, since there is no evidence whatsoever that Twain ever wrote or said it. 

There are well over 1,000 dams in California, some more than a century old. Most dams were erected to establish critical water supply, but also for hydroelectric power generation and flood control. If Shasta and Keswick Dams in Shasta County were removed, towns like Redding could literally be washed away during spring flooding season. But there are still plenty of old dams, structures that no longer serve their original purposes, that could be removed to give wild salmon and steelhead access to ancestral spawning habitat.

Illustration: Dams Out, CalTrout

California Trout (CalTrout) is currently promoting the removal of a list of dams that they say have outlived their usefulness; four are in northern California and one just over the border in Oregon. None of these aging structures are part of the vital State Water Project or Central Valley Project. CalTrout is in business for “Ensuring resilient wild fish thrive in healthy waters for a better California.”

Scott Dam

Scott Dam. Photo: PG&E

By the time Scott Dam on the Eel River is up for relicensing in 2022, the structure will be 99 years old. It was built to provide hydroelectric power for the growing city of Ukiah, and it forms Lake Pillsbury. Before the dam was installed, the Eel hosted some of the most dramatic salmon and steelhead runs in California. The few remaining fish are now listed as threatened under the Federal Endangered Species Act. Because the dam prevents the normal, seasonal flushing of sediments in the river, the water is considered “impaired” under the Clean Water Act. 

According to CalTrout, “The Eel represents perhaps the greatest opportunity in California to restore a watershed to its former abundance of wild salmonids.”

When old dams come due for relicensing, they are required to meet 21st century standards for fish passage. Upgrading these ancient structures comes with enormous cost, so much so that it is often cheaper to just remove the dams entirely. While the environmental benefits of dam removal are quickly realized, it nevertheless presents real challenges to landowners and water users. In the case of Scott Dam, a significant amount of Eel River water is piped over to the Russian River where farmers and winemakers depend on these flows. Northern California struggles with semi-chronic drought scenarios, so dam removal often includes agreements to compensate agricultural interests when there is not enough water to meet their needs.

While the removal of Scott Dam is not yet a certainty, CalTrout describes the likelihood of success as “a distinct possibility.”

Klamath River Dams

Copco Dam on the Klamath River. Photo: California Trout

Four Dams on the Klamath River, three in California and one in southern Oregon have been identified for removal as soon as 2021 at a cost of $450 million. Iron Gate, Copco #1, Copco #2 and J. C. Boyle Dams make up the Klamath River Hydroelectric Project, and removing them will be the largest dam removal project in the world. It will also open up hundreds of miles of salmon and steelhead spawning habitat. COPCO is an acronym for the original builder of the project, California Oregon Power Company. After merging with Pacific Power and Light in 1961, the company rebranded itself as Pacificorp. 

For years Pacificorp refused to consider removing the dams. It was only after they looked ahead and began to contemplate what it would cost to upgrade the dams for fish passage. Long story short, it didn’t pencil out. It became obvious that it would be cheaper to just remove them.

Thousands of salmon died on the Klamath River in 2002. Photo: Northcoast Environment Center.

According to CalTrout, “A non-profit organization, the Klamath River Renewal Corporation (KRRC), was formed in 2016 to take ownership of four PacifiCorp-owned dams (Copco #1, Copco #2, Iron Gate and JC Boyle), for the purpose of overseeing the dam removal process. That work will include restoring formerly inundated lands and implementing required mitigation measures in compliance with all applicable federal, state, and local regulations. PacifiCorp will continue to operate the dams until FERC approves a license transfer to KRRC.” (The 2019 Report, Top 5 California Dams Out)

Iron Gate Dam is located northeast of Hornbrook, CA and is the first barrier to endangered salmon and steelhead in the Klamath River. It also forms Iron Gate Reservoir. 

Copco Dam on the Klamath River. Photo: California Trout

Copco #1 and #2 Dams are just east of Iron Gate. Copco #1 forms Copco Lake, while Copco #2 (just below Copco #1) diverts nearly all of the Klamath River flows (2,500cfs) 1.5 miles downstream to the powerhouse at the head of Iron Gate Reservoir. The canyon section of Klamath River that is all but dewatered by Copco #2 was historically a set of steep rapids. Today the project leaves barely a trickle of water in the canyon (10 cfs).

J. C. Boyle Dam is the uppermost structure slated for removal. It is about 12 miles over the Oregon border just west of the community of Keno,OR. 

The Science Behind Dams

Oroville Dam. Photo: Department of Water Resources

Dams degrade water quality. They also block the rich nutrients brought into the habitat by spawning anadromous fish. The salmon and steelhead using our rivers for spawning have traveled and fed in thousands of miles of ocean water from as far away as Canada, Alaska or even Russia. When they die after spawning these exotic nutrients supercharge the ecosystem benefiting all forms of life. The reservoirs behind dams warm and broaden the river corridor often providing warm water habitat for destructive non-native species. Even though many dams provide fish ladders allowing passage over the dams, they are largely statistical failures. For reasons known only to the fish, many fish will not use them. This creates a large pod of fish below the dams that will never spawn. The dams also give piscivorous species (fish that eat other fish) like pikeminnows a terrific opportunity to dine on salmon and steelhead smolts that will never make it to the ocean.

Dam removal is about much more than restoring endangered fish populations. If you consider the fact that everything in an ecosystem is connected, you realize you cannot alter one aspect of a river without impacting everything else. Once streams are returned to their natural states, they are able to cleanse themselves, wash out all the sediments that smother aquatic plants, insects and fish. Improved water quality also impacts everything from associated wetlands (and the life sustained there) to coastal beaches and estuaries. 

So, you think California has a dam problem? We are far from alone. According the the US Army Corps of Engineers, there are over 80,000 dams three feet or greater in this country. California is on the cutting edge of a national movement for dam removal where the benefits outweigh the costs for retrofitting century-old structures built in an age where we thought we had an endless supply of good habitat. 

As communities strive to wrestle with all of the complex economic and environmental hurdles involved in dam removal, more are deciding the benefits outweigh the costs. Not all dams are good candidates for removal, but enough of them are to feed a growing national movement to come up with win-win scenarios for fish, ecosystems and human beings. It’s nearly everyone’s dam business.

Chip O'Brien

Chip O'Brien is a regular contributor to California Fly Fisher and Northwest Fly Fishing magazines, and author of River Journal, Sacramento River and California's Best Fly Fishing: Premier Streams and Rivers from Northern California to the Eastern Sierra. He lived in Redding, California, for eighteen years, where he was a guide, teacher, and regional manager for CalTrout.


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