Klamath Dams – Is the Iron Gate Dam Diversion Tunnel Damaged?

An April letter from the Federal Energy Regulatory Commission suggests that if the Iron Gate Dam diversion tunnel is damaged or becomes blocked, the dam removal project grows in complexity and potential risk cover image credit: George Moss Driscoll; Klamath River & Dam Removals FB page

An ‘Open Letter’ discussing the situation sheds light on recent developments at Iron Gate Yurok X tweet

TO:  Siskiyou County California Board of Supervisors

CC: Concerned Citizens

RE:  Federal Energy Regulatory Commission (FERC) Letter Dated 4-9-24 (attached)

Via Email Only – April 18, 2024 – OPEN LETTER – Public

3 attachements

Dear Chairman Kobseff – Honorable Supervisors :

I am writing you due to a very serious concern that stems directly from a logical review the Letter from FERC dated April 9, 2024, to Mark Bransom/KRRC, Shannon Davis and Tony Meyers (See Attached). 

The final EIR and Plan for the Decommissioning of the Klamath River Dams, and specifically, Iron Gate Dam were supposedly reviewed and approved by numerous parties and engineers, as well as KRRC and Mr. Bransom. And they have reminded us that over and over; it’s all as planned.

However, as we have all witnessed, KRRC has gone ‘off-plan’ in the past, and item #1 in FERC’s letter alludes to that in regard to Iron Gate Dam. 

Of course we all saw the numerous photos by fishing guides of the  massive native fish kill when FERC went ‘off plan’ and drained the Lakes in a matter of days, instead of months, as detailed in their public presentation. 

We now learn that ‘exploratory drilling’ by Kiewit was suddenly halted, as discussed in the correspondence between KRRC and FERC. Some correspondence (data) is not being released for public examination-consideration because KRRC alleges it’s protected as part of National Security, which is related to the energy grid. Are they hiding something the public should know for their own risk mitigation?

However, Iron Gate Dam no longer has any equipment present related to electrifying the grid, and as such is no longer part of the grid. 

A logical person might wonder why a non-applicable national security caveat is arguably being used to withhold information to the public as to recent events regarding Kiewit at Iron Gate Dam, which is a publicly-funded project. 

That withheld information might be critical to potentially taking measures, and/or informing citizens of evolving risks and mitigating risks, in order to protect the health, safety and welfare of the Citizens living below Iron Gate Dam.

Furthermore, we also know for a fact that the special anti-cavitation pipe that was installed and anchored with steel anchors inside to the walls of the diversion tunnel failed, and that massive pipe blew out of the diversion tunnel during the dewatering process and broke into pieces. 

As a result, the diversion tunnel, which is handling the entire flow of the Klamath River, no longer has the engineered protection to prevent cavitation resonance and erosion in the tunnel, which has the potential to cause the tunnel failure if the volume and pressure of water passing through the tunnel reaches the point where it starts cavitation resonance. 

There is a body of engineering science that warns of tunnel failure that can result from Cavitation Resonance. In the FERC Letter, item # 5 discusses a diversion tunnel failure. 
See attached engineering review; ‘

Cavitation damage and the Tarbela Tunnel collapse of 1974′ by M.J.KENN & A. D. GARROD

Clearly the Regional Engineer from FERC, Mr. Douglas Johnson understands this potentially catastrophic diversion tunnel failure issue and has concerns.

According to earthen dam engineer, Stephen Koshy’s letter (attached), the deconstruction (‘breach’) of a clay-core dam like Iron Gate Dam is considered a very risky deconstruction process. Furthermore, Dr. Paul Houser, former Science Integrity Officer for the Department of Interior (DOI) cited Stephen Koshy’s concerns in his list to concerns to the DOI in regard to Iron Gate Dam.

Obviously, Kiewit stopped exploratory drilling according to FERC’s letter. WHY? 

Did Kiewit run into something of concern to them? And if so, don’t citizens and their elected officials have a right to know what, exactly, in detail is going on? 

The FERC letter stated: “…Kiewit has aborted the Iron Gate Development drilling program in its entirety…”Arguably, as a result of some concerns related to recent events, FERC’s Regional Engineer concluded his Letter by saying:

“We cannot authorize the Iron Gate Dam removal at this time based on the above comments.”

KRRC has made the ridiculous statement that these posits are “inaccurate”. 

However, these posits all stem from FERC’s own letter!  

Is KRRC and Mark Bransom claiming that FERC is somehow misrepresenting the situation?

Considering the FERC Letter in concert with the attached engineering reports, and in light of the diversion tunnel’s failed anti-cavitation pipe (ripped out of the tunnel), the potential for escalating problems of a devastating nature are now firmly in the realm of possibility. 

And the It’s quite clear that the FERC letter is requesting answers to their ‘what if’ questions! 

Is it fear mongering when the United States Coast Guard asks a boat captain if the vessel has proper life jackets and life-raft? Does it suggest that boat could sink? Absolutely. 

And the County deserves to ask and get answers to important questions designed to assure the health, safety and welfare of citizens living down-river below the Iron Gate Dam! 

Important Questions:

Are there devices that monitor dam movement and evolving dam failure? Are there sirens that would be triggered if there was an impending dam collapse?  

Some people seem to forget that just because the lake is mostly drained, the clay in the core of the dam is like heavy mud (see Koshy Letter), and if it loses containment, it will come oozing out and move down river potentially knocking homes off their foundations, etc.  

There is the potential for loss of life and severe property damage should the clay core lose containment, according to engineer Stephen Koshy. 

Quotes from FERC’s Letter (attached in original form)

“We (FERC) have reviewed the information provided and have the following comments: 

1. We note that the removal methods and/or timelines have changed for various features at all three remaining developments (e.g., Copco No. 1 spillway gates, Iron Gate embankment dam). Please provide an updated schedule for our records. 

2. We concur with the comments provided by the BOC. We note that KRRC’s response to BOC Comment 2 states that a prefabricated headwall and wingwall attachment will be utilized to ensure a watertight transition between the spillway approach channel and the penstock inlet. Please provide the proposed design for the headwall and wingwall and a detailed description of how they will be installed as a supplement to Attachment B of the subject submittal. In addition, please have the BOC review the headwall/wingwall design and address any comments that they may have. 

3. Provide additional documents and drawings which include a detailed description of the penstock intake tower removal procedure, timing, and sequence (with particular attention to the transition from passing emergency flows through the intake structure to passing them via the emergency spillway channel). 

4. The BOC’s review did not include a review of the early breach contingency plan (Attachment E of the subject submittal). Please provide their review and address any comments that they may have. 

5. The early breach contingency plan discusses the possibility of performing an early breach of the dam if a diversion tunnel blockage occurs or forecasts indicate increased flows and a rise in reservoir level (see Steps 5 and 6 of the plan). If the diversion tunnel is blocked, the embankment has been excavated below the invert of the emergency spillway channel inlet, and there is water against the breach plug (i.e. a scenario where the reservoir cannot be lowered and inflows are anticipated that could submerge the breach plug), explain how the breach plug will be removed to the final river channel grade without excavation equipment being submerged and/or washed away (e.g. the excavator boom can reach the final river channel grade without having to work in wet conditions; the breach can be achieved by other means; or justify that this scenario is not plausible). 

6. According to Mr. Sean Iiams’ March 27, 2024 email to Ms. Elisabeth Jacquot-Matt of this office, Kiewit has aborted the Iron Gate Development drilling program in its entirety negating the requirement for the DPP. Therefore, we will not provide comments on the DPP. We remind you that you may not proceed with exploratory drilling in any of the project embankments without prior authorization from this office. 

We cannot authorize the Iron Gate Dam removal at this time based on the above comments. Within 60 days of the date of this letter, please provide responses to or a plan and schedule addressing the comments above. File your submittal using the Commission’s eFiling system at When eFiling, select Hydro: Dam Safety and Portland Regional Office from the eFiling menu. The cover page of the filing must indicate that the material was eFiled. For assistance with eFiling, contact FERC Online Support at [email protected], (866) 208-3676 (toll free), or (202) 502-8659 (TTY). Thank you for your continued cooperation and interest in dam safety. If you have any questions, please contact Ms. Jacquot-Matt at (503) 552-2712. 

Douglas L. Johnson, P.E. 
Regional Engineer”

FERC-LETTER-TO-KRRC-4-9-24 Cavitation-damage-and-the-Tarbela-Tunnel-collapse-of-1974 KoshyLetter032812toGuarino-1

Respectfully Submitted,
William E. Simpson II – rancher – citizen

One Comment

  1. Joshua Israel

    Great article once again William! You are the one courageous gentleman that is writing on these topics concerning the Klamath River. You are writing on the topics that no other “so called journalist” is addressing. You are the one beacon in the desert. I hope the river recovers in the years to come. I grew up in Klamath County and know this river well. My one hope now is that KRRC compensates the brave and noble patriots of the once glorious COPCO Lake and the brave residents themselves! We are in your debt Mr. Simpson!!! Keep reporting on the subjects that aren’t being addressed or covered up.

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