Featured News, Siskiyou

Klamath River Dams – KRRC’s Sediment Plan – A Ticking Time Bomb?

cover image courtesy Bieke Lieckens – KRRC contractors dumping hundreds of tons of polluting sediments into Jenny Creek, which empties into the Klamath River.

The Klamath River Renewal Corporation (‘KRRC’) has been misinforming everyone! And when anything goes terribly wrong, they claim it’s ‘as planned’.

The 15-million cubic yards of remaining toxic lake bottom sediments pose a very real and significant threat to the ongoing health and recovery of the Klamath River.

Genuine advocates for River restoration might actually be interested in WHY the foregoing is true.  And when dam removal advocates learn the scientifically supported truth, they should be very alarmed and upset with Klamath River Renewal Corporation and its staff.

There is already arguable evidence that KRRC likely knew that there were toxins and heavy metals in the sediments that would impact human health, safety and welfare as well as the lifeforms in the Klamath River. 

As a result of the sediments dumped into the main-stem of the Klamath River by KRRC, the Siskiyou County Heath Department has had to issue a press release warning people to stay out of the Klamath River!

First off, in order to actually understand the exigent threat that remaining sediments present to the proper restoration of the Klamath River, we need to truly understand the nature and the quantity of the sediments remaining in the now exposed canyon lake bottoms of the lakes that existed behind Iron Gate Dam, Copco 1 Dam and Boyle Dam.

According to the published 2006 study of the lake bottom sediments behind the Klamath River dams by GATHARD ENGINEERING CONSULTING of Seattle, Washington, Section 7, item 1 on page 94 reads: 

“Approximately 20.4 million cubic yards of sediment is trapped in the four lower most reservoirs of the Klamath River Project. Most of the sediment, 78% of the total for all dams, is smaller than silt sized material”.

(Note for clarity, sediment particles in ascending size are classified as: clay, silt, sand and gravel)

In the foregoing quoted statement, we see subtle, yet important wordsmithing! It’s fact that sediment particles smaller than silt areclay’. The authors don’t want to use that term (‘clay’) because, as a suspended sediment, clay is arguably the most harmful to all aquatic life. 

The Dirty Truth – Impacts of Fine Sediments on Fish Habits

“Imagine yourself stuck in traffic with the inability to move.  You’re tired and hungry, but unable to get to your house, restaurants, or stores.  Now imagine yourself on clear streets with easy access to anything you need close by.  Similarly, fish thrive in waterways where they can move freely and food, shelter, spawning grounds, and rearing habitat are readily available.  In rocky streams, channel complexity involves having abundant pools and riffles, logs offering shelter, clean gravels, streambank growth, and side-channel habitat.  Excessive fine sediment (clays, silts, and sand < 1 mm diameter) threatens this complexity, limiting habitat.  In fact, the US EPA classifies excessive fine sediment as a pollutant and streams identified as having excessive sediment are listed for remediation. [1]”

Figure 1. Fish are happier with greater channel complexity.

Soil Erosion and Sediment Pollution

“Although sediment is a part of the natural environment, human activities sometimes increase the amount that ends up in our streams. These sediments are usually fine grained sands, silts and clays that can cover up coarser sediments and the spaces between rocks and cobbles that provide habit for aquatic life.

Responsible construction practices and landscaping can greatly reduce the amount of sediments entering our streams.

Excess eroded sediment degrades habitat

• Suspended sediment decreases the penetration of light into the water. This affects fish feeding and schooling practices, and can lead to reduced survival.

• Sediment reduces the amount of light penetrating the water, depriving the plants of light needed for photosynthesis.

• Sediment particles absorb warmth from the sun and thus increase water temperature. This can stress some species of fish.

• Settling sediment can bury and suffocate fish eggs and bury the gravel nests they rest in.

• Suspended sediment in high concentrations can dislodge plants, invertebrates, and insects in the stream bed. This affects the food source of fish, and can result in smaller and fewer fish.

The stream-bottom sediments on the left provide spaces for fish to lay eggs and for invertebrates to live and hide. Excess erosion has deposited fine grained sediments on the stream bottom to the right. There are no spaces available for fish spawning or for invertebrate habitat.

• Excess sediment from eroding soils contains organic matter that contributes to oxygen depletion in the water as it is decomposed.

• Eroding soils also contribute the nutrients nitrogen, and especially phosphorus. In low nutrient streams and recovering waters such as Duluth’s streams and Lake Superior, these can contribute to algal growth and oxygen depletion.

• Suspended sediment in high concentrations irritates the gills of fish, and can cause death.

• Sediment can destroy the protective mucous covering the eyes and scales of fish, making them more susceptible to infection and disease.

• Sediment may carry toxic agricultural and industrial compounds such as heavy metals and pesticides. If these are released in the habitat they can cause abnormalities or death in the fish.

• Sediment loads in our waterways often result in further increased erosion and instability of stream banks, causing stream channels to become wider and shallower, which leads to warmer water temperature.”

At the February 13, 2024 Special meeting of Siskiyou County Board of Supervisors held at Copco Community Center, Mr. Mark Bransom, the CEO of KRRC, represented the total lake bottom sediment quantity as “17-20 million metric yards”.  

During the Feb. 13th meeting, which was about 3-weeks after the Iron Gate Dam tunnel was opened and the massive dump of water and polluted sediment was unleashed, Mr. Bransom stated they had sent about 5-7 million metric yards (assumed to be cubic meters) of sediments down the Klamath River. He further stated, that amount was equivalent to the normal amount sediment transported down the entre river annually. 

As the resulting ecological disaster proved, adding an entire year’s worth of fine sediment in a matter of just a few days killed billions of life forms, including native fishes, a well-documented fact via hundreds of photos and videos.

For more than a year, Mark Bransom and/or Ren Brownell had shown a visual presentation that contained a slide depicting the schedule for de-watering the lakes. ‘The plan’..

That schedule, which was presented to the public over and over, and socialized for more than a year, showed that the lakes would be de-watered slowly over the course of about two months. 

Without any warning, dialog or input to or from the Siskiyou County Board of Supervisors or the communities living on and around the lakes and the Klamath River below the dams, KRRC went off-plan and dumped the water and sediments out of the lakes via the tunnel at Iron Gate Dam over the period of just a few days, instead of months!

That single act devastated the entire Klamath River aquatic ecosystem, killing billions of lifeforms, including native species organisms and fish, and adversely impacted the terrestrial wildlife along the entire river. There are also numerous reports of crustaceans (crabs, etc.) washing up dead or dying on the coastline around the mouth of the Klamath River.

That act also adversely impacted water quality for humans, pets, livestock and wildlife.

That dumping process began on January 23rd 2024, just one week before the USGS sediment and water survey was publicly released on January 31, 2024.  Coincidence or something else?

The interesting thing about the USGS sediment and water survey, which was conducted from 2018-2022, is that no sampling was made of lake bottom sediments. However, by scientific deduction, and empirical experience with EPA and DEQ settling ponds, it’s no stretch to come to the logical conclusion that; the relatively high background levels of heavy metals found and being transported by the Klamath River waters and sediments above the lakes would be highly concentrated over time in the lake sediments. The lakes behind the Klamath River dams act exactly in the same manner as a ‘settling pond’, only the lakes are more efficient due to size and current reduction. It’s a fact that the lakes were remediating the toxins being carried by the River.

“Heavy metals in stormwater are primarily removed by sedimentation in structural BMPs. These sediments may be toxic to benthic invertebrates and aquatic microorganisms”

~EPA publication.

“Empirical evidence is information acquired by observation or experimentation. Scientists record and analyze this data. The process is a central part of the scientific method, leading to the proving or disproving of a hypothesis and our better understanding of the world as a result.”

 ~ LIVE SCIENCE – Empirical Evidence – A Definition

It’s a plain fact that just the 5-7 million yards of sediment dumped into the Klamath River on January 23, 2024 over the course of the next few days killed the Klamath River! 

If we are truly engaged in this phenomenally expensive experiment to restore a fishery in the Klamath River, does it make any sense whatsoever to keep sending the same deadly polluting sediment down the Klamath River? 

It’s a fact that there is at least another 3-times as much sediment (~15-million cubic yards) remaining in the exposed lake beds as was initially allowed into the Klamath River, which killed the River!

What happens when another 5-7 million cubic yards (of 15-million) or more of the remaining toxic sediments comes down the Klamath River during a small flood?  

Many people are aware that even floods over wide flat valleys will strip-off cover-crops and the underlying soils, move boulders and dislodge trees.

Is anyone foolish enough to believe that seeding some plants and grasses on the 15-million cubic yards of exposed lake-bottom clay sediment beds will stop the erosive power of a torrent of flood water rushing through the narrow Copco and Iron Gate canyons?   Well, that’s the fairy tale that KRRC and their contractor Resource Environmental Services, LLC (‘RES’) wants to sell you.  

The answer is now well known… Any more sediment events may result in the permanent Death of the Klamath River. And any restoration of the fishery or river that has been accomplished between now and the next flood will be wiped-out, costing taxpayers hundreds of $-millions more!

How many times can you send toxic sediments down a river before you kill it forever?  Do we need more insanely expensive experiments to learn that answer too?

Leaving those sediments in the line of the next flood is a ticking time bomb.

As responsible citizens who care about the health of the Klamath River and its recovery from a horrific experiment, we must now demand that KRRC remove ALL remaining polluted sediments as soon as possible. 


  • Lane, E. W.  (1955) The importance of fluvial morphology in hydraulic engineering. Proceedings, American Society of Civil Engineers, No. 745, July.
  • Rosgen, D. (1996).  Applied River Morphology.  Wildland Hydrology, Lakewood, Colorado. 
  • 2009-2011 sediment analysis by CDM Smith and Stillwater Sciences


  1. Paula Wigell

    Shame on the Klamath River Renewal Corporation and the California government officials who approved the KRRC’s actions. How intensely short-sighted, and illogical their decisions have been. Animals have died senseless, painful deaths from the toxins released and families have lost their livelihoods by this AVOIDABLE disaster.

  2. Michele Willis

    What can “we,” as concerned individuals do to help mitigate the removal of the toxic sediments from the lake bottoms? Can you please provide the addresses and contact information for letters to be written to request this work to be done? Or does this request need to be in the form of a petition?

  3. Fom the CDM-Stillwater report you cite:

    “The results of this evaluation suggest the Klamath Reservoir sediments can be
    considered relatively clean, with no chemicals present at levels that would preclude their release
    into downstream or marine environments. Accordingly Klamath Reservoir sediments are
    expected to pose no adverse effects, limited effects, or minor effects under the five exposure
    pathways under the Proposed Action and No Action alternatives.”

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