Category Archives: Northern California

Klamath Dam Removal is Complete – How well did it go?

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The final steps in Klamath River dam removal are complete, and the first salmon has migrated upstream into the dam-removal reach in over 100 years.  The four reservoirs were drained last winter and the dams removed this summer.  The river is now free in its natural channel. Two dams remain up at Klamath Lake (Keno and Link dams – not part of the project), but the lower four hydroelectric project dams – three in Oregon and one in California – are gone.  With the demolition of the last of these lower four dams this summer, the Klamath is running free from its headwaters in southeastern Oregon to its mouth in the Pacific Ocean on Yurok tribal lands in northwestern California.  Hundreds of miles of spawning grounds are open to Chinook salmon, Coho salmon, and steelhead for the first time in more than a century.

The dam-removal process was not without problems, although these problems were generally foreseen in planning and permitting.  First was the reservoir draining process this past winter, when the reservoirs were drained, from mid-January to mid-February.  In the four-dam reach and in the Klamath River downstream, high suspended fine sediment and low dissolved oxygen were problems, though determined of limited risk to the few salmon and steelhead in the river at that time.  However, the Assisted Sediment Evacuation project element (Figure 1) continued past its prescribed end date of March 15 into early April, extending the presence of lethal levels of suspended sediment into the early juvenile salmon and steelhead emigration season from tributaries, a season that includes March.  Lethal levels of suspended sediment extended downstream over 100 miles as far as Orleans (Figures 2 and 3).

Subsequently, during the summer, dam infrastructure was removed to provide full salmon passage past the dam sites.  Low flows necessary to access the dam sites for material removal, and high summer air temperatures, resulted in very warm water temperatures beginning in July.  Removal of coffer dams and further Assistant Sediment Evacuation at the dam sites (Figure 4) led to the return of lethal sediment levels in the river below Iron Gate (see Figure 2).  On three days, dissolved oxygen below Iron Gate reached zero. 

Though approved by the project technical team, the high suspended sediment level through September likely hindered a major portion of the fall-run Chinook salmon run up the Klamath River (Figure 5).  Only 60 adult salmon were reported at the Shasta River trap as of early October, by which time daily numbers are usually in the hundreds.  Numbers at other traps at other tributaries were even lower, which perhaps explains why only one salmon has been seen at the new sonar station above the Iron Gate Dam site.

With the cessation of Assisted Sediment Evacuation at the end of September, the hope is that suspended sediment levels will return to the low pre-summer levels and fall-run Chinook salmon will recommence their migration upriver.  The river should be clear for late fall and winter runs of coho salmon and steelhead. 

The use of Assisted Sediment Evacuation in winter and early spring, and then again in late summer, will remain controversial, if only in that it was applied under an extended time frame from the original planning and permitting documents.  The summer application was certainly a surprise to local stakeholders,1 who were shocked by the extent and duration of the muddy and smelly river conditions.  A condition of zero dissolved oxygen for 50 miles below Iron Gate dam for two days in September was not approved under the permits issued by the state or federal governments.

In my opinion, the initial and final evacuation of muddy sediment should not have been implemented by using excavators to dump sediment directly into the river.  A better option would have been natural removal by winter storm events that would have provided a much higher dilution factor and would have had a better chance for a non-lethal concentration of suspended sediment.  Furthermore, more of the sediment should have been removed or stored in upper terraces and not allowed to enter the river.

The NOAA Fisheries final assessment of the dam removal effort failed to acknowledge the problems and potential consequences of the spring or summer events. 

“Heavy equipment removed the final obstacle separating the Klamath River from the Pacific Ocean on Tuesday. The reconnected river was turbid but remained safe for fish after crews took steps to avoid erosion and impacts to water quality.”  The river was not safe for salmon or steelhead for over 100 miles downstream.

“Crews used a strategy of releasing sediment and organic material that muddied the river but avoided a decline in dissolved oxygen that could have otherwise harmed fish.”  Untrue.  Both dissolved oxygen and suspended sediment levels were lethal.  Hopefully, many fish were able to avoid these conditions.

Figure 1.  Photo of Assisted Sediment Evacuation process from Iron Gate Reservoir in March 2024.  (KRRC video screengrab)
Figure 2.  Turbidity (as measured in FNUs) in lower Klamath River in 2024.  (Karuk water quality data). See Figure 3 for locations.  Red line is approximate lethal concentration for salmon.
Figure 3.  Lower Klamath River USGS water quality sampling stations.  (source: USGS)
Figure 4.  Assisted Sediment Evacuation associated with the removal of Copco No. 1 Dam cofferdam on August 14, 2024.  The mainstem Klamath flow is coming from bypass tunnel in upper center of photo. 
Figure 5.  Timing of fall-run salmon return (daily counts) to the lower Shasta River weir-trap in years 2017-2020.  (CDFW data)
  1. See Facebook (Klamath River & Dam Removals) ↩

Park Fire – Spring-Run Salmon’s Worst Nightmare

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The fire that started on July 24 has burned most of the lower foothill and middle reaches of the affected streams as of August 8th.  It is now actively encroaching on the mountain spawning reaches of Mill and Deer creeks on the south slopes of Mt Lassen, the two most important of the affected spawning streams (see maps below).  It will likely slow only when it reaches the boundary of the 2021 Dixie Fire and its lower levels of fuels.

Map of Park Fire in northeast Sacramento Valley dated 8/3/2024.  Red arrows indicate further fire growth as of 8/6, mainly in the upper Mill and Deer creeks watersheds.  Green stripes indicate spring-run salmon summer holding and fall spawning reaches.

Spring-run salmon populations in the Central Valley, including the core Battle, Mill, Deer, and Butte Creeks populations, are at recent historic lows.  It is essential to rehabilitate previously burned watersheds as soon as possible.  The California Department of Fish and Wildlife should expand the Deer Creek Spring-Run Conservation Hatchery Program begun in 2023 at UC Davis to include the other spring-run salmon streams in the Sacramento Valley. 

At the same time, it is important to attack the causes of poor survival of juveniles migrating to the ocean and poor survival of adults returning to the spawning grounds.  In this regard, comments on the Environmental Impact Statement for the Long-Term Operations of the Central Valley  Project and the State Water Project are due on September 9.  Operations of these water projects play a major role in the survival of Central Valley salmon to and from the ocean.  With the acceleration of climate change, it is important to re-evaluate the present and future effects of these water projects and potential operational changes to protect salmon under this new climate change baseline.

For more on Mill and Deer creek salmon see:  https://www.facebook.com/CaliforniaDFW/videos/spring-run-chinook- salmon/306327998810027/

Park Fire active zone moving northeast in the upper Mill Creek watershed on August 8th, 2024.  CALFIRE hopes to stop the Park Fire advance at highways 32/36 and the boundary of 2021 Dixie Fire (see next map).

Park Fire active zone moving northeast in the upper Mill Creek watershed on August 8th, 2024.  CALFIRE hopes to stop the Park Fire advance at highways 32/36 and the boundary of 2021 Dixie Fire (see next map).

Western boundary (extent) of Dixie Fire in summer 2021.

Klamath River Update – July 2024

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It is the first summer without the reservoirs on the Klamath River.  Upper river flows at Iron Gate are now at summer lows (900 cfs, Figure 1).   The flow, water temperature, and turbidity in the river without the reservoirs (the dams have not all been removed) is shown in the following figures.  Two major concerns are sporadic turbidity events from dropping flows and higher water temperatures that are a consequence of unshaded former reservoir reaches and loss of cold-water dam releases.

Extensive gaging data are available for the lower Klamath River from the USGS and Karuk Tribe (Figure 2).  The focus here is on the reach below the four-dam-removal project where the dams were drained in early 2024, leaving the river free-flowing.

Late spring and early summer gage data show the upper reaches below Iron Gate had the warmest water in 2024 (Figures 3-5).  Water temperatures reached 25oC/77oF, lethal to salmonids.  Further downstream, water temperatures were gradually cooler as the river progressed toward the mouth, generally remaining in the 68-70oF maximum range after receiving cool tributary water and cooler air temperatures.  Further upstream above Iron Gate, water temperatures were similar those immediately below Iron Gate (Figure 6).

Prior to dam removal, the upper reaches below Iron Gate had the lowest water temperatures in 2022 and 2023 (Figure 7 and 8), reflecting the release of cold water from the bottom of Iron Gate Reservoir.  Without this source of cold water, the upper reaches are now significantly warmer in late spring and summer. 

Because the water temperatures were similar in 2024 above and below the former Iron Gate Reservoir (see Figures 4 and 6), there seems to be little warming in the unforested former Iron Gate reservoir reach.  The upper reach of river below Iron Gate Dam now generally reflects historic warm water characteristics of the 6-dam project reach between Klamath Lake and Iron Gate Dam.  Future riparian forest restoration of the three former reservoir reaches may lead to some cooling of the upper river in the future.

Finally, the drop in river flow in early July 2024 (see Figure 1) appears to have caused additional reservoir-footprint erosion and scouring, leading to high turbidity levels below Iron Gate (Figure 9).  Such turbidities like the warm water are generally lethal to salmonids.

Figure 1.  Upper Klamath River flow at Iron Gate gage in June and early July 2024.

Figure 2.  Lower Klamath River gauging stations from Klamath Lake downstream to mouth.  Blue marker denotes gage below JCBoyle Dam.  Numbers in green and yellow circles denote multiple gage locations.

Figure 3.  Water temperatures in lower Klamath River in June 2024.  Iron Gate Dam is uppermost location and Turwar Gage is lower-most location near mouth.  Note greatest water temperatures were recorded from the two uppermost reaches:  Iron Gate and Walker Bridge.

Figure 4.  Water temperature recorded at Iron Gate gage 6/15-7/7 2024.

Figure 5.  Water temperature recorded at Walker Bridge gage 5/20-7/7 2024.

Figure 6.  Water temperature recorded at Fall Creek gage 6/1-7/7 2024.

Figure 7.  Water temperatures in lower Klamath River in June-July 2022.  Iron Gate Dam is uppermost location and Turwar Gage is lower-most location near mouth.  Note lowest water temperatures were recorded from the two uppermost reaches:  Iron Gate and Walker Bridge.

Figure 8.  Water temperatures in lower Klamath River in June-July 2023.  Iron Gate Dam is uppermost location and Turwar Gage is lower-most location near mouth.  Note lowest water temperatures were recorded from uppermost reach: below Iron Gate.

Figure 9.  Turbidity (suspended sediment) concentrations measured at Iron Gate Gage in 2024.  Note original reservoir drawdown and subsequent reservoir sediment deposit erosion January-

Klamath River Salmon and Steelhead Recovery – The Future

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After dam removal, the plan for recovering Klamath River salmon and steelhead is relatively straightforward.

Oregon is going to focus on watching to see how steelhead repopulate the upper watershed and on having a more active role in developing spring-run Chinook salmon populations.  Without an existing spring-run stock, Oregon will try establishing one by out-planting stock from California’s Trinity River Hatchery.

California will focus on recovery of existing lower river spring-run Chinook and fall-run Chinook, Coho, and steelhead stocks.  The new Fall Creek Hatchery will sustain the fall-run Chinook, Coho, and steelhead stocks formerly produced at the now-closed Iron Gate Hatchery.  Lower and middle river wild spring–run and fall-run Chinook, Coho, and mainstem and tributary steelhead stocks should expand with improved water quality and access to new habitat.  Historical tributaries offer great potential as does the spring-fed reach of the mainstem near the Oregon border.

In the decades ahead, as the populations and habitat recover, state, federal, tribal, and stakeholder groups will work together toward Klamath salmon and steelhead recovery.

There will be a need to coordinate management of the three H’s:  hatcheries, harvest, and habitat.  Existing hatchery programs should be converted to a single conservation hatchery program focused on salmon and steelhead recovery.  Such a program will need a new hatchery to support the recovery of Klamath spring-run Chinook, as in the San Joaquin River Restoration Program.  The Pacific Fishery Management Council and the two states will have to protect the recovering populations with strict harvest regulations.  Considerable funding will be needed to restore fire-damaged and drought-damaged watersheds, former reservoir footprints, mainstem and tributary fish passage, and spawning and rearing habitat.

Water supply management will remain contested and challenging.  Adequate funding, cooperative efforts, and adaptive management will bring success.

Klamath Dam Removal Update – April 6, 2024

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Video Screen Grab of lower Jenny Creek ASSISTED SEDIMENT EVACUATION PROJECT

In a March 20 post, I related events in the Jan-Feb 2024 period of the Klamath Dam Removal Project.  The initial four-reservoir drawdown in January led to abrupt increases in streamflow, suspended sediment, and low dissolved oxygen levels above and below Iron Gate Reservoir (the lower reservoir).  This was followed by lower stable streamflow, high dissolved oxygen, and declining suspended sediment.  Streamflow pulses from upstream Klamath Lake in late February and early March resulted in (short-term) elevated suspended sediment from exposed sediment erosion in the four reservoir reaches.  These circumstances were expected as part of the four Dam Removal Project.

In March, the Assisted Sediment Evacuation Project began in the Jenny Creek floodplain of the Iron Gate Reservoir footprint.   That project has led to lethal doses of suspended sediment (turbidity) in the lower Klamath River below the Iron Gate Dam site (Figures 1-3).  Project approvals, such as the National Marine Fisheries Service’s (NMFS) biological opinion quoted below, included provisions to stabilize sediments after the January drawdown, but not to flush sediments into creeks and the Klamath River.

Post drawdown and dam removal, crews will be working to actively restore the exposed reservoir footprints and tributary mouths that flow into the former reservoirs. To reduce elevated suspended sediment concentrations (SSCs), the Renewal Corporation will take active measures to flush sediment from the reservoirs during drawdown and then immediately begin stabilizing remaining sediment after drawdown has been completed. Revegetation, channel construction, and placement of habitat features such as logs and boulders will minimize erosion and allow passable channels to form in preparation of fish presence. (NMFS Biological Opinion p. 14)

The origin of the high suspended sediment levels was likely from the exposed bed of Iron Gate Reservoir (particularly the Jenny Creek arm), not upstream reservoir erosion during the Klamath Lake flow pulses.  Sediment levels below Iron Gate Dam were low during the flow pulse that diluted the high sediment loads from Iron Gate Reservoir (Figure 1).  Gages below Copco and JC Boyle reservoirs were lower, generally below lethal levels (Figure 4).

Chinook salmon fry are abundant and most prevalent in the lower Klamath River below Iron Gate Dam in late winter (February-March).  Coho and steelhead fry are more abundant later during spring.

The Assisted Sediment Evacuation Project is slated to end on April 15.  I recommend that it cease immediately, with efforts shifted to “stabilizing remaining sediment,” in order to minimize impacts of the project on Klamath River salmon and steelhead.

Figure 1. Turbidity and streamflow in the Klamath River below Iron Gate Dam (rm 193) in January to March 2024. Note turbidity of 300-500 SBU is roughly 1000-2000 mg/l total suspended sediment (TSS). Such levels are considered lethal for juvenile salmon and steelhead.

Figure 2. Turbidity and streamflow in the Klamath River near Seiad Valley below the mouth of the Scott River (rm 145) in March 2024.

Figure 3. Turbidity and streamflow in the Klamath River near Seiad Valley about ten miles upstream from the mouth of the Scott River (rm 145) in March 2024.

Figure 4. Turbidity and streamflow in the Klamath River just upstream of Iron Gate Reservoir and below Copco dams in March 2024.