Matilija Dam, photo by Patrick Maloney

DAM REMOVAL UPDATE: Klamath Dams, Matilija Dam, and the Potter Valley Project

The California Advisory Committee on Salmon and Steelhead Trout (CAC) was re-established by the Legislature in 1983 in response to public concern about declining populations of salmon and steelhead.   The role of the public committee is to advise the Director of Fish and Wildlife and the Legislature, via the Joint Committee on Fisheries and Aquaculture (JCFA,) on salmon and steelhead issues within California that are of concern to the public.  The CAC consists of eleven members who are appointed by the Joint Committee on Fisheries and Aquaculture.

At the July meeting, committee members received an update on the Klamath Dams, Matilija Dam, and the Potter Valley Project dam removal projects.


Joe Croteau is a program manager for the Department of Fish and Wildlife in the northern region who is working to implement elements of the Klamath Hydroelectric Settlement Agreement.  He provided a general overview of what they are trying to accomplish, noting that he is not a member of the Executive Team and so there may be some questions he won’t be able to answer.

Brief project history

The Klamath Hydroelectric Settlement Agreement (or KHSA) is a multi-party agreement signed in 2010 and amended in 2016 to remove the four hydroelectric dams on the Klamath River.  The signatories of the KHSA formed the Klamath River Renewal Corporation, a non-profit entity designed to remove the dams. 

There four hydroelectric dams are owned by PacfiCorp.  The FERC license for those dams expired in 2006, and so PacifiCorp sought to relicense the dams.  As a condition for relicensing, FERC required two major conditions: construction and operation of fish passage facilities at the dams and to obtain a Clean Water Act certification.  This made the dams no longer economically viable for PacifiCorp so they instead started looking into other options, ultimately signing the KHSA.

Before the dams can be taken down, the license must be transferred and then surrendered.  On July 16, FERC approved a co-license transfer between PacifiCorp and KRRC.  If that is agreeable to everybody, then KRRC and PacifiCorp will need to apply for a license surrender to FERC and FERC needs to approve the license surrender.

There are four dams to be removed:  Iron Gate Dam is the furthest downstream and is about ten miles east of Interstate 5; then there are the Copco Dams, and then in Oregon is the JC Boyle Dam.

By removing these dams, we’ll be opening up about 400 miles of anadromy in the Klamath River and its tributaries, which would be huge,” Mr. Croteau said.  “Also, Iron Gate Dam was built primarily to manage flows coming from Copco 1 and Copco 2 and because those are hydropower facilities, they drive the system for most parts of the day for most of the year.  So Iron Gate was built to maintain flows, and then we put a hatchery in below that to supplement fish production.”

The Klamath River Renewal Corporation was stood up in 2016 shortly after the Klamath Hydroelectric Settlement Agreement was signed.  It has engaged Kiewit, the largest construction company in water resources in the country, as the progressive design-build contractor.  The Corporation is being advised on liability protection by Aeon, the world’s largest insurance advisor, and they’ve engaged Resource Environmental Solutions out of Houston, Texas to provide an indemnification package that will benefit the states and PacifiCorp, as well as affected counties and private property owners.  There is a team that will carry out the hatchery design to completion, restoration and permit implementation.

In May of 2020, the project received a new 401 certification.  “We got that done on time,” said Mr. Croteau. “Kudos to the State Water Board for doing that, it was a huge undertaking and a major part of this removal project.”

The license transfer was anticipated about the first quarter, late spring of 2020.  The FERC order in July 2020 required that PacifiCorp remain on the project as a co-licensee; they had sought to transfer the license entirely to KRRC, so the project is paused until the signatories can figure out what the next best step is. 

The co-licensee transfer is something that has to be well vetted and agreed to by especially PacifiCorp,” said Mr. Croteau.

California’s role in dam removal

Parcel B lands: “The KHSA says we’re going to be getting those lands post dam removal, so we have to figure out how we’re going to manage those lands when this goes through,” he said.  There are about 31 parcels ranging various sizes that total 7000 acres of ‘Parcel B’ lands currently under water.  Within those parcels, there are three or four recreation sites that they will try to retain post-dam removal.  There are other sites that will be high grounded and contemplated later. 

Post-dam recreation plan: The next task is to develop a post-dam recreation plan.  “There’s a lot of recreation that happens on that stretch of river,” he said.  “The recreators are well unified and organized and we’re going to be working with them on post dam recreation.”

Yreka water diversion: The City of Yreka has a water diversion on the Klamath that connects to a 15 mile diversion tunnel that stretches from one of the tributaries down to Yreka.  “We’re going be opening up anadromy to them so they are pursuing either an HCP or a response from the agency saying they don’t need an HCP.”

Post-dam removal hatchery design and production:  Mr. Croteau said this has been the biggest topic of discussion for the past eight months, trying to make sure all the issues out there with the agencies, tribes, and commercial fishermen, and the private sector are addressed.  In June, a 50% design was completed for the Fall Creek Facility, which is upstream of Iron Gate.  “The holding capacity is for about 100 coho salmon adults and 200 chinook salmon adults to ideally spawn at Fall Creek.  We’re targeting to produce 75,000 coho yearlings each year – or ten fish per pound.  That’s how engineers think – in fish per pound.  So up to about 3 million chinook subyearlings at about 90 fish per pound.  And then we’re going to hold about 115,000 chinook yearlings and release them at 10 fish per pound to mimic some of the life history that chinook exhibit in this system.”

Post-dam removal monitoring:  They will be expanding the monitoring program from below Iron Gate up to the Oregon border, such as adding weirs and screw traps.  Mr. Croteau noted that there is already substantial restoration monitoring of the salmonids from Iron Gate to the ocean.  “We work with other agencies, tribes, and stakeholders to monitor juvenile and adult traps in the Klamath and many of its tributaries,” he said.  “We’ve put millions of FRTP dollars into habitat improvements like removing barriers, upgrading fish screens, building side channels.”

Permitting:  There is a lot of permitting to be done under both the California Endangered Species Act and Lakebed and Streambed Alteration Agreements.  There are also listed species other than fish and they have to comply with all of the state regulations to be successful.

Integrated Fisheries Restoration Monitoring Plan

In anticipation of dam removal and increased restoration momentum, the Integrated Fisheries Restoration Monitoring Plan was put into motion.  The IFRMP is currently a work in progress; it is facilitated by Environmental Social Systems Analysis or ESSA.

The IFRMP is being developed and supported by the federal, state, and local governments.  When completed, the IFRMP will provide a unified framework for planning the restoration and recovery of native fish species from the headwaters of the Klamath Basin to the Pacific Ocean while improving flows, water quality, habitat, and ecosystem processes.  The IFRMP can serve as a blueprint that describes the highest priority watershed restoration actions and provide a strategy to recover the Klamath Basin after dam removal.

This program is what we’re focusing on for post dam world restoration from the California border all the way down to the ocean,” said Mr. Croteau.

July 16 FERC Order

The July 16th FERC order approved the a license transfer contingent upon PacifiCorp remaining as a co-licensee.  PacifiCorp had sought to transfer the license completely to KRRC as a way to avoid liability, so the Department of Fish and Wildlife and other policymakers are meeting with PacifiCorp and other signatories to evaluate the different scenarios and next steps, he said. 

The transfer order was a little later than hoped and a little bit different than expected, but from Mr. Croteau’s point of view, it’s something they can work with.  “The KHSA supports flexibility in the transfer order so long as the conditions are mutually agreeable, so if PacifiCorp agrees to being a colicensee and a coapplicant for surrender, then we can move forward without amending the KHSA.”

Click here to read/download the FERC order.

Lessons learned

Lastly, Mr. Croteau gave his lessons learned so far.

A general approach is that there’s no time, money, or patience for a do-over,” he said.  “We preach over and over again that failure is not an option at this point.  We can’t go back.  We feel like this is our best opportunity to make this happen.  And so, we’re in a place where we’re trying to be nimble, and CDFW continues to work on its assigned tasks, such as Parcel B, etc.”

Another lesson learned is you need to be nimble and prepared for the unexpected.  There’s always things that happen that you’re not prepared for so you can’t give up and you have to be creative and circle the wagons every time something new comes up.”

One thing I’m learning a lot is that people need to communicate early and often,” Mr. Croteau continued.  “There’s a lot of social engineering that goes on with this project.  I’ve gotten to a place now where I have put a few of the tribes and recreators together to talk about coexisting and I’ve heard from them both that they wish those conversations were started two or three years ago.  Another thing I’m experiencing is changes to agency staff, KRRC, staff, contractors, and policies, so the more you can minimize change in a project like this, the better.

The last thing here is that no one person or entity is bigger than the project itself,” he said.  “There’s been a lot of people that have helped with this project but if anybody thinks they can do this by themselves or one entity can do this by themselves, it’s going to fail because it’s way bigger than anyone can really imagine by themselves.  So before I end, I want to acknowledge there are many folks on this call and hundreds of others that have been working on this project.  It’s an interesting and complex project, and I hope those efforts are rewarded.”


Prior to the construction of Matilija dam, Matilija Canyon was an actively used recreation area with a productive steelhead fishery.  Construction began in 1946 and was completed in 1947; the reservoir began to fill up the next year.


The dam was originally 198 feet tall with a reservoir capacity of 700,000 acre-feet.  In the 1960s the dam was notched, and in the 1970s it was notched a second time.  Currently, there is about 8 million cubic yards of sediment behind the dam, and of the 700,000 acre-feet, only about 400 acre-feet is estimated to be left.

Rich Burg, Environmental Program Manager at California Department Fish and Wildlife then gave a brief update on the efforts so far:

Final design plans funded

The Wildlife Conservation Board funded the final design plans in May at approximately $5 million.  They are continuing to work on the sediment modeling and they are at 10% now.  They expect to be at 30% design by around December.

Two bridges will need to be rebuilt:

The Camino Cielo bridge which is immediately downstream.  They are looking to acquire property for that and are waiting for the DGS to approve the appraisal.  There are preliminary design plans, but they are waiting to see whether or not properties can be acquired to decide what design may or may not happen.

The Santa Ana bridge which is further downstream.  The property has been acquired and funding for the designs has been in place and it should be out to bid this August for the actual construction which is likely to start sometime early 2021.

Downstream levees:

They are working on alternative facings for the Minor Oaks, Live Oaks, and Casitas Springs levees.  The funding has already been acquired and it is in the preliminary to intermediate design phases right now.

Other issues:

They are looking at options for the Robles Diversion for alternatives for that water supply.

In early July, Ventura County Public Works opened a 12” release valve on Matilija on the behest of the California Division of Dam Safety because they had concerns. 

The water is being drained right now.  We had staff up there a couple weeks ago, it had very limited capacity to begin with.  The pictures I saw a few weeks ago, you could see the sediment pretty much up to the rim of the dam, so really it’s time to remove this dam.”

Q&A highlights

Darren Mierau asked about the levee design.  Is that installation or removal of levees?  Mr. Burg said it’s for a combination of both, for flood protection of housing downstream and a couple of communities.  There was another question about why there is so much emphasis on downstream improvement of structures for flood when Matilija doesn’t have any flood control capacity.  Mr. Burg said that he didn’t know the specifics, except that a couple of the local communities got involved once they knew the dam was going to be removed; their concern was extreme rain events causing high flows.

A fellow I can only identify as Ethan said, “It’s my understanding it has something to do with the increased deposition that’s being predicted, so ith increased deposition at some of the infrastructure, there’s a concern that will increase just the water surface height during those flood events and increase the risk of flooding.”

As it sits now, that’s due to the current bridges downstream which narrows the river channels which is one of the reasons once they expand the bridge, based on the new design, especially the Santa Ana bridge, there may be flooding impacts downstream in that area,” added Mr. Burg.


Lastly, Darren Mierau, North Coast Director with California Trout discussed the Potter Valley Project.  Cal Trout is one of the five planning agreement parties involved in pursuing the license from PG&E. 

Project background

The Potter Valley Project is located in the headwaters of the Eel River watershed and extends down to the southern end of the watershed where it borders the Russian River. 

The map on the right shows the footprint in the headwaters of the Eel River outlined in a lighter color white with the Russian River watershed in the orange color to the south.  The map on the left shows more detail about the project itself and the watershed above it.

There are two parts to the Potter Valley Project.  One is the PG&E licensed hydropower project and the other is the water project delivering water to the Russian River that’s currently used for agricultural water, for irrigation and domestic water supply.

We’re obviously focused on the hydropower project and the relicensing of that by PG&E, but in the mix is the implication of the relicensing or not relicensing of the project for this water supply,” Mr. Mierau. 

Scott Dam forms Lake Pillsbury and stores about 75,000 acre-feet of water collected from winter and spring snowmelt and runoff.  The water flows downstream about 12 miles to the next downstream dam which is Cape Horn, which is primarily a diversion facility with very little storage capacity.  At Cape Horn Dam, the water enters the hydropower tunnel and then transfers into the Russian River basin, coming out the powerhouse at the foot of the flume to generate hydropower. 

After the hydropower is produced, the water is abandoned and then basically received by the downstream water users, both in the Potter Valley itself and then a little bit farther downstream it flows into Lake Mendocino where it becomes part of the operations for the Sonoma Water.

FERC Relicensing decision

The FERC license for the Potter Valley Project is set to expire in 2022, so in 2017, PG&E initiated its integrated licensing process for relicensing the project, but then in 2018, withdrew the application.  With that withdrawal of the application, there are two different pathways: either they proceed down a surrender and decommissioning pathway that would be overseen by FERC, or as is happening now, several entities have stepped in to try to provide a pathway to maintain that license and some of the benefits it provides, Mr. Mierau said.

He noted that Scott Dam currently is impassable to salmonids, so one of the key considerations is providing fish passage over that dam is to the upstream habitat.  “We have estimated several hundred miles of habitat for chinook salmon and steelhead, and potentially for summer steelhead recolonization as well,” he said.

Alongside the process of relicensing, Congressman Jared Huffman initiated an ad hoc committee that brought most of the parties together that were involved in overseeing the relicensing, but in a separate process to begin a constructive conversation about the project itself and the relicensing process.  Then partway through that, PG&E announced that they were withdrawing their license application so the parties had to contend with that and decide what to do.

Two Basin Partnership emerges

As a result, Humboldt County, Sonoma Water, Mendocino County Inland Water and Power Commission, the Round Valley Indian Tribe, and Cal Trout formed the Two Basin Partnership.  A planning agreement was developed which was submitted in May of 2019 to FERC that recommended they consider the partnership entity as a viable solution to taking over the license in the long-term and modifying the project, but maintaining the license itself, power production, and the water supply delivery to the Russian River.

The FERC filing in 2019 set in motion the planning agreement partnership process to conduct a feasibility study to determine if it was feasible to meet the planning agreement objectives.  There are several different phases to the feasibility study.  The first phase was completed about March of this year which resulted in a feasibility study report that was filed with FERC in May of 2020, in which the partnership proposed a project plan.

The second phase of that feasibility study is currently ongoing.  Cal Trout applied for on behalf of several of the planning agreement partners for funding to the Department of Fish and Wildlife from the Cannabis Program and received that funding to continue that feasibility study.  The second phase is continuing to understand the implications of the project plan that has been proposed.

The project plan

Currently, the project plan involves the removal of Scott Dam as the best viable pathway to achieve fish passage into the upper watershed for listed threatened salmonids. 

They have proposed to ‘modify’ Cape Horn Dam; Mr. Mierau noted that they settled on that term ‘modification’ to encompass either removal of Cape Horn Dam or some kind of modification of the fish passage facilities because if a better water diversion facility infrastructure cannot be determined to replace the current Cape Horn Dam infrastructure, they will leave Cape Horn Dam in place and instead likely make significant upgrades to the fish passage facilities to enable passage of salmonids, lamprey, and other fish. 

With respect to water supply, they propose to continue water diversions from the Eel River to the Russian River at approximately the same volume of water that occurs now, which is about 65,000 acre-feet per year, but instead shift the season of diversion from storage and delivery in the summertime to a winter run of the river diversion. 

We have modeling results that indicate this is feasible not only for the diversion volume but also for maintenance of Lake Mendocino water supply that is important for operations and downstream releases, so we have some solid feasibility level analysis that that will work,” said Mr. Mierau.

Similar to the Klamath dam removal project, they are looking to establish a new regional entity that would eventually hold the FERC license.  They have a committee focusing on that; it may entail legislation in the future, but they haven’t proposed that yet.

The last major piece of the project plan right now is an extensive Eel River and fisheries restoration program.  “Once the Scott Dam facility and reservoir are removed, we’ll have to treat the sediments that’s currently stored in that reservoir and restore river channels, riparian vegetation, and so forth,” he said.  “So we’ll be proposing a broader Eel River restoration plan as part of our project.”

Next steps

Mr. Mierau said the work is pretty much ongoing right now.  With the PG&E bankruptcy settlement, they can now initiate discussions with PG&E over several different aspects of the project, including funding of FERC studies that will be required by our license application as well as some kind of settlement with them related to infrastructure transfer to the regional entity. 

We’ll be continuing to look at options for establishing a regional entity, whether it’s through state legislation and so forth,” he said.  “As our feasibility study is ongoing, we’ll continue to gain new information to refine our project plan.  One of the activities that’s going on right now is development of our FERC studies that will be major activity over the next six months, coming forward with those proposed FERC studies, seeking public input on what those studies will be and then looking to FERC to approve some level of FERC studies to be implemented.”

He acknowledged it would be an expensive endeavor, so they are developing a financial plan that will enable removal of Scott Dam and treatment of sediments as needed, either stored onsite or released downstream of Scott Dam and what balance of those two options would be best for the river. 

We’ll be looking at Cape Horn Dam modifications, including upgrades to the power house and relicensing studies.  We need to finance that, and then as part of our Two Basin Solution Commitments to the Potter Valley Irrigation District and the Potter Valley irrigators, we will be looking at ways to achieve water supply reliability for those entities that currently receive water from the Potter Valley Project.  Our best estimates to date right now are from $100-400 million for this project as a whole.  We’ll be refining that as we go forward.”

There is a website with more information and documents at .

The role of the Department of Fish and Wildlife

Allan Renger is a Senior Environmental Scientist Supervisor at California Department of Fish and Wildlife. The Department has been engaged on the Potter Valley Project in a regulatory way for quite some time; Mr. Renger has been assigned to the project for the last ten years.  The current license and the administration of that for the benefit of salmon and steelhead has been a significant effort and focus of the Department, he said.

There are two department employees assigned to the Potter Valley Project: Allan Renger and Matt Myers, the FERC coordinator and the two of them comprise the team for the project relicensing.  The project is coordinated with the Department’s Conservation and Engineering Branch, who have provided significant technical expertise to fish passage and the various alternatives for passage that have been vetted. 

Besides Region 1, Region 3 which encompasses Sonoma County and the water issues associated with the Potter Valley Project affects fisheries of the Russian River greatly.  Scott Dam is located in Region 2, and has a warm water fishery associated with that lake; they also provided significant comments regarding Elk herds.  They are coordinating with these other regions as well as the fisheries branch, he said.

The Eel River is California’s third largest watershed, and the recovery potential for salmonid species is significant in the Eel River in comparison to some of the rest of California,” said Mr. Renger.  “There are water issues that exist but they are not insurmountable, and they are being addressed through a number of venues, including this relicensing.  There’s a significant amount of restoration occurring from the estuary to these headwaters, and the estuary itself is, in comparison to other places in California, relatively less developed.”

Fish passage

Scott Dam, the upper dam, is 168 miles from the mouth of the Eel River and has no provisions for fish passage.  Cape Horn Dam, the more downstream of the two dams, does have a fish passage facility.  The dam was built in 1908 and the first passage facilities went in shortly after that. 

Fish ladder at Cape Horn Dam; photo by Natalie HG

The passage facilities, when you stand beside them you can see vestiges of every passage attempt that’s been made here, and it’s really interesting archeologically just to look at,” Mr. Renger said.  “But the consequence of that is a passage facility that does have limitations.  It is inundated by gravel under higher flow events and they have to close the passage facility.  It was closed for a significant portion of the steelhead run three years ago, and that happens periodically in the larger flow events.

We have some recent telemetry regarding passage efficiency even when it is open that we historically didn’t have,” he continued.  “Some steelhead are entering that ladder and taking a significant amount of time to make it through the ladder – more than several days.  Some fish are passing easily and some fish are passing over several days, so then the passage efficiency of Cape Horn is also something that needs to be looked at.”

There is a small hydropower facility at Cape Horn Dam that provides power to the City of Ukiah, but he noted it’s relatively small and hasn’t produced its potential in many years, he said.


There have been a couple analyses of habitat associated upstream of Scott Dam, Mr. Renger said.  There are two significant forks of the river that occur above the dam, and then a large number of smaller tributaries, so it’s anywhere 55 to several hundred miles of habitat associated with above the dam, depending on which analysis, but it is significant and in the hundreds of miles, he said.

Annually at Cape Horn Dam, there are steelhead and chinook passing, and Mr. Renger said they believe that some of this habitat has a need to provide summer steelhead habitat.  He noted that the Middle Fork of the Eel River lying just to the north here has similar elevations providing summer steelhead habitat, and so that’s a significant aspect of what this habitat provides that is not provided at other locations in the main stem Eel River.

There was a pilot project to pass lamprey at Cape Horn Dam installed four years ago; it’s an innovative technique involving a tube whereby lamprey bypass the ladder and pass the dam via the tube.  There were 11,000 lamprey that passed through the tube two years ago, but there seems to be wide variations in the number of lamprey passing this location. 

I believe it’s slightly less than a hundred this year – 90 to 11,000 lamprey passing this in the four years that we’ve been studying this,” he said.

The Department weighs in

The Department of Fish and Wildlife were members of the ad hoc committee and participated in a fish passage analysis of options on the Eel River both at Scott Dam and Cape Horn Dams. The results of that initial analysis indicated much higher viability of recovery potential for the upper Eel River steelhead and upper Eel River chinook populations with removal of Scott Dam,” Mr. Renger said.  “It removes the issues associated with juveniles navigating the lake, the different lake levels that occur under different times of the year that fish would need to pass it, and predatory fish that are currently occupying the lake associated with Scott Dam.”

In May of 2020, the Department of Fish and Wildlife submitted a letter to the planning parties that preferred fish passage alternative for the project would be one that includes Scott Dam removal and as well as significant improvement to Cape Horn Dam or removal of Cape Horn Dam.  In May 2020, the relicensing parties shortly afterwards submitted their feasibility study and that did include a feasibility study of a proposal to remove Scott Dam and a hard look at Cape Horn Dam to figure out what passage alternative was feasible and provided the best recovery potential for salmonids at Cape Horn Dam.

Mr. Renger noted that in June, the Department as well as many other agencies and interested parties submitted comments on the relicensing study.

Q&A highlights

A question was asked about the water that’s diverted from the Eel to the Russian.  If the FERC project goes away, since that water is foreign water, does the right to that water go away, too?  Would Sonoma Water Agency just be out of luck? 

First of all, Sonoma Water doesn’t have a water right to any of the water,” said Darren Mierau.  “They receive it as it is abandoned from the project but it’s not under a water right. The Potter Valley Irrigation District does have a water right, but it is associated with the project, so if the project goes away and the means for diverting the water goes away, then obviously the water right would go away as well.  That’s one of the underlying factors bringing the parties together to work together is that we have what we call regional control over the fate of that water and ability to control restoration of fish passage into the watershed, as opposed to not doing what we’re doing, allowing FERC to take direction, and to potentially recommend or order decommissioning but with some uncertainty about what that would entail.  So we’re being proactive to try to maintain control over those aspects instead of defaulting to FERC.

I’ve been on this Potter Valley advisory group of Huffman’s for a few years,” said Committee member Vivian Helliwell.  “I think it’s great that the five parties are going forward with their attempt to get relicensing.  They’ve decided to focus on winter-only diversions, because really the only way they can get water to Potter Valley is to get a power license because otherwise they lose the diversion completely.”

Now it seems the power plant is a real money loser,” she continued.  “It doesn’t produce much at all and it’s far from the grid.  But the water has developed an economy around it for a hundred years.  So the water would not be coming through in the summer but only the winter, and then it would have to be pumped back up to Lake Mendocino ten miles to Potter Valley in the summer, which is separate from the project licensing.  It’s good progress going forward with these negotiations.  Lake County is very concerned about it because they are losing Lake Pillsbury which they see as their main money source in a poor county.  They are also at the advisory table but not the application table.

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