The following is an op-ed composed by UC Davis-trained geologist Bob Schneider and UC Davis’s Senior Ecologist Dr. Chad Roberts. Remember, opinions expressed do not necessarily reflect that of MendoFever, nor have we checked the submission for accuracy:
The Pacific Gas & Electric Company (PG&E) is surrendering the Federal Energy Regulatory Commission (FERC) license for the Potter Valley Project (PVP). PG&E identifies this action as a business decision because of the project’s failure to produce revenues that offset its operating costs, even though PG&E customers pay higher rates for delivered energy than just about everywhere else in the Unted States. In our opinion, PG&E has determined to rid itself of the PVP for a different kind of economic consideration, after determining that the Scott Dam represents an economic liability that the company cannot afford. A key factor in this determination is the increased understanding of the seismic hazards represented by the Bartlett Springs Fault Zone (BSFZ), which runs through Lake Pillsbury approximately 5000 feet east of Scott Dam.
As part of the PVP relicensing process, FERC held an auction for potential alternative licensees for the PVP. No takers made offers to accept the ownership of and responsibility for this existing hydropower license, for the same reason that PG&E does not want the responsibility for these existing conditions: a recognition of the outstanding risk that the BSFZ represents for the PVP licensee.
The history of the PVP doesn’t need to be repeated here, but the scientific understanding of Earth sciences that has developed in the past century, which is critical in considering the best options for the future of the PVP, is less well-known. The geological framework represented by plate tectonics is particularly significant in understanding the circumstances presented for the PVP. The dynamics of plate tectonics were not understood in the early 1900s when the Cape Horn and Scott Dams were designed and constructed. Over this past century, the scientific understanding of plate tectonics (including the Bartlett Springs Fault Zone) has developed continuously, and most of our current understanding of how tectonic dynamics affect northwestern California has developed fully only in the most recent 30 years.
A short summary of western California’s geological history shows that until about 28 million years ago the western continental margin was a “subduction zone” with the Farallon Plate subducting beneath the western margin of the North American Plate. West of the Farallon Plate was another plate (the Pacific Plate), with a surface movement direction toward the northwest. When the margin between the Pacific Plate and the Farallon Plate reached the edge of the North American Plate, the relative dynamics of the plate boundary changed to become a “transform margin”, with the Pacific Plate moving northwest relative to the North American Plate. This margin is known today as the San Andreas Fault Zone (SAFZ).
The SAFZ is not just a line on a map, but a 50-mile-wide zone of fault activity on a number of collateral major faults in addition to the San Andreas Fault itself. The Bartlett Springs Fault Zone is the easternmost fault in the SAFZ. The BSFZ extends 50 miles from the Middle Fork of the Eel River southeast to Round Valley, past Lake Pillsbury and Bartlett Springs to just north of Cache Creek. Related faults in the same alignment system to the south include Wilson, Hunting Creek, and Green Valley faults.
Nobody we know can accurately predict when a seismic event might occur. However, based upon the length of the fault zone and other criteria geologists can estimate the potential magnitude of a major seismic event. Recent studies have identified the Bartlett Springs Fault as capable of producing an earthquake of Moment Magnitude between 6.7 and 7.2 (as documented by geological studies published by B.L. Melosh et al. 2024, V.E. Langenheim et al. 2023, and J.C. Lozos et al. 2015).
Earthquakes with magnitudes between 6.7 and 7.2 are major seismic events. Prior events within the memories of individuals living in northern California that fall within this magnitude range include the 1994 Northridge Earthquake (M6.7), the 1992 Cape Mendocino Triple Junction Earthquake (M7.2), the 1989 Loma Prieta Earthquake (M6.9), and the 1980 Eureka (Gorda Plate) Earthquake (M7.3).
The 1992 Mendocino Triple Junction event (M7.2) resulted in damage in Ferndale (in Humboldt County) very similar to the damage that occurred in Ferndale from the 1906 (M7.9) event in San Francisco. The 1980 Gorda Plate earthquake (M7.3) resulted in a collapsed Highway 101 overpass near Humboldt Bay. The 1989 Loma Prieta Earthquake (M6.9) was on an oblique fault very close to the San Andreas Fault in the Santa Cruz area, and may be more directly indicative of effects associated with the Bartlett Springs Fault at Lake Pillsbury. The event was memorialized on TV because it occurred at the start of a World Series game in San Francisco. Long sections of the I-580 freeway in Oakland collapsed during the quake, and a large part of the Marina District in San Francisco was damaged because of liquefaction in the poorly consolidated fill on which it was built.
An earthquake in this magnitude range on the Bartlett Springs Fault in the vicinity of Lake Pillsbury could result in an immediate failure of Scott Dam as a consequence of the seismic shaking per se. Moreover, the existing large landslide at the south end of the dam, on which the south abutment is based, would likely be mobilized (as occurred widely in northwestern California in 1992 with the Triple Junction event), leading to the destruction of the south end of the dam, and the rest of the structure would follow. This location was not then, and is not now, a safe location for a dam.
Dams do fail and while the specific dynamics are different, the St Francis Dam failure in Los Angeles County in 1928 is a relevant example. A common joke among geologists is that a sure way to find a new fault is to look for an older dam, an indication of how significant a risk geologists consider fault movement to be with respect to dam safety, particularly for older structures. Geological science clearly indicates that the BSFZ represents a significant risk of failure for Scott Dam. While we have yet to see the internal studies conducted by PG&E for the Scott Dam, we suspect that those studies say the same. We strongly believe that discussions among members of the public and their elected decision-makers about the future of the Potter Valley Project should include a greater appreciation of these geological realities.
I call BS. The dam has been there for more than 100 years and has survived many many large earthquakes. I’m sure that PG&E sought out specific geologist that would provide them with the opinion they desired. I doubt it was objective. I’m sure you could find just as many geologist that would agree the dam is stable. SAVE LAKE PILLSBURY. If the lake were to become part of the national Forest, the army core of engineers could retrofit the dam and add a fish ladder and it would cost significantly less than the $500 million that decommissioning will cost. Although the tribes will lose out on all that money for river restoration. This is a leftist political scheme. And dam removal is a regional catastrophe in waiting. The dam removal proposition makes me sick to my stomach. I can’t hardly stand to read about it anymore.
That is an uninformed WISH on your part. Go find a few geologists who who support your opinion and publish your argument. The dam is coming down and your whining is not going to save it.
This is a geologist and an ecologist. Neither are qualify to discuss the seismic resistance of a dam. You are not informing yourself by WISHING that the people with letters behind their names writing an opinion piece are correct instead of seeking the science and a broader picture.
Notice the use of the word “could.” “Could” is anything that is not impossible as a matter of physics. Ie, you COULD have a meteor come through your roof tonight and collapse your chest right where you are sleeping. It COULD happen. And therefore i suggest sleeping somewhere else! Staying in the same spot denies that risk of what COULD happen.
So sure, it is true that a fault zone capable of a 6.7-7.2 Moment Magnitude. Nice that they were able to narrow it down to a range of .5 on a logarithmic scale. Which means a doubling of energy.
As it is the fault hasn’t done anything higher than a 5.1 during recorded history. It’s a right lateral strike slip fault, meaning not a thrust fault.
Which are important considerations when considering the robustness of a dam design.
I WISH these two had used their collective educational attainment and intellectual genius to out out some data about what is LIKELY and to obtain some insight from an engineer or two.
You have zero idea what you’re babbling about. A geologist is exactly who understands this matter. This dam is coming down. The issue is a long history of Russian river water mismanagement, a horrible reengineering of the river in Healdsburg and beyond that dropped the water table and reduced riparian areas.
JC,
Seismology is a sub-discipline of geology.
Geologists are very well prepared to assess AND discuss earthquake risks to structures and the viability of the structure of soils to which human constructions are attached.
These are the key references that we utilized in preparing our Op-Ed. They are all publicly accessible and folks are welcome to download and study them.
References:
Langenheim, V.E., McLaughlin, R.J., and Melosh, B.L. 2024. Integrated geologic and geophysical modeling across the Bartlett Springs fault zone, northern California (USA): Implications for fault creep and regional structure. Geosphere 20(1):129–151. https://doi.org/10.1130/GES02684.1.
Lozos, J.C., Harris, R.A., Murray, J.R., and Lienkaemper, J.J. 2015. Dynamic rupture models of earthquakes on the Bartlett Springs Fault, Northern California. Geophysical Research Letters 42:4343–4349. https://doi.org/10.1002/2015GL063802.
McLaughlin, R.J., Moring, B.C., Hitchcock, C.S., and Valin, Z.C. 2018. Framework geologic map and structure sections along the Bartlett Springs Fault Zone and adjacent area from Round Valley to Wilbur Springs, northern Coast Ranges, California (ver. 1.1, September 2018). U.S. Geological Survey Scientific Investigations Map 3395, 60 p. https://doi.org/10.3133/sim3395.
Melosh, B.L., Bodtker, J.W., and Valin, Z.C. 2024. Geologic map and structure sections along the southern part of the Bartlett Springs Fault Zone and adjacent areas from Cache Creek to Lake Berryessa, northern Coast Ranges, California: U.S. Geological Survey Scientific Investigations Map 3514, 2 sheets, scale 1:24,000, 20 p. pamphlet. https://doi.org/10.3133/sim3514.
Ohlin, H.N., McLaughlin, R.J., Moring, B.C., and Sawyer, T.L. 2010. Geologic map of the Bartlett Springs Fault Zone in the vicinity of Lake Pillsbury and adjacent areas of Mendocino, Lake, and Glenn Counties, California. U.S. Geological Survey Open-File Report 2010–1301, scale 1:30,000. https://pubs.usgs.gov/of/2010/1301/.
This lake will survive. Just let the politics play out. A seismic shift is coming lol. Not one that will destroy the dam but a political shift.
I remember you Mr. West. Are you the retired biology instructor that I had at Mendocino College? The one that had a crush on my mom while she was in nursing school in the late 80’s? Sorry that may have been inappropriate.
Sorry Paul West. I had you mixed up with a different guy named West. My apologies.
Did you even read the article? The south end of the dam is anchored in a landslide, aka gravel for practical purposes in a major quake. The word “liquefaction” has meaning, in this case a potentially catastrophic one for everyone and everything downstream.
To your points: “The dam has been there for more than 100 years and has survived many many large earthquakes.” I will presume you mean earthquakes NOT on the Bartlett Springs Fault, which puts their relevance into question. Scott dam DID survive a 5.1 quake in 2016 on the BSF, but the important piece of data is that in the upper range of predicted possible quakes on the BSF, a 7.2 releases OVER A THOUSAND TIMES THE ENERGY of a 5.2. Also: one hundred years is less than a blink of an eye on a geologic timescale. Shit happens. The idea that “it can’t be true because I’ve never seen it” is ill informed at best.
Point 2: “I’m sure that PG&E sought out specific geologist that would provide them with the opinion they desired.” Yes, paid experts are a dime a dozen. IF the geologist in questions’ opinion is an outlier within his or her profession then you might have a valid point. IF.
Point 3: “the army core of engineers could retrofit the dam.” Negative. Scott dam would need to be removed in it’s entirety and be replaced with a wider more robust structure anchored in bedrock. Full stop.
Point 3: “This is a leftist political scheme.” Again, negative. It is a public safety issue, an environmental issue, and in the eyes of PGE, a corporate liability issue. I understand it’s all in vogue these days to politicize environmental concerns as “leftist schemes” but PGE’s shareholders don’t GAF about the environment and still want the dam to come down. Go figure.
Point 4: ” dam removal is a regional catastrophe in waiting.” If by that you mean “Regional water users, municipalities and farmers will have to alter the ways they allocate and consume a limited resource” then yeah, I agree with you. But if you mean “OUR AMERICAN WAY OF LIFE IS UNDER ASSAULT DAD GUMMIT!” well again, yeah, that was always going to happen. Welcome to the future.
I drive through Potter Valley 3 or 4 times a year out to the Eel River canyon. I’ll be a sad as anyone to see Potter shrivel up and blow away when the water’s gone. Those bright green hay fields are such a pretty a sight in June and July. I hope they find a way to keep the water flowing or at least some of it, but Scott Dam’s obituary is already written.
Even brilliant people may reject evidence when it threatens what they want to believe.
Remember, Bradley Beck has probably paid admission to the Creation Museum. He doesn’t believe in “geologic timescales”. Evolution is a liberal hoax and the Jurassic period is a liberal Hollywood plot to make money!
Not so. I have climbed across Scott dam as a kid. Swam at its base before 9-11-01 when they made public access almost impossible. That dam isn’t going anywhere. I’m not a geologist but I do have a geography degree. I understand plate tectonics and liquefaction. This dam has already stood the test of time. When a quake big enough comes along that can destroy the dam then we have much bigger problems on our hands. SAVE LAKE PILLSBURY.
Exactly! Save Lake Pillsbury and any other water storage these chuckleheads want to tear out!
They don’t depend on this water. We should be building more water storage.
In the event of an earthquake and dam failure, what damage would be expected to happen?
The lake everyone cares about would no longer be there and rebuilding the dam would cost too much. The result is the same no matter what. Earthquake or humans will take it out because it’s not supposed to be there. Potter Valley is supposed to be dry. It’s historically the driest valley in the county. Potter Valley’s historic dryness is NEVER brought up, because the steamy wetland that’s there now is so green and lush.
The Russian used to dry up completely in the heat of summer. That’s what is does. Has anyone ever thought that the fish aren’t there anymore cause we’ve created a constant unnatural flow? There’s build up and release in all systems, and that’s what’s messed up.
All that’s happened in PotterValley since those dams is the creation of entitlement at everyone else’s expense.
All true enough. But there were also many fewer people and towns along with big ag reliant on the water the current system now supplies. Maybe bringing it up to spec might be the best solution for our present reality. Plenty of public money goes into less worthy enterprises.
Big ag, like wine and weed
Supposed to be dry. But it’s not dry. And many generations have built ranches and farms in PV based on a water diversion that began around 1908. I repeat myself yet again. 600,000 people depend on this water diversion and the water flows all the way to Marin County. Lake Pillsbury must remain and I believe it will. Let’s call it a hunch. I don’t have a PhD behind my name, but I understand the basics because I have a BA degree in geography which included many geology classes that included plate tectonics. A previous comment stated that the largest earthquake in recorded history on that fault is 5.1. I don’t know if that is true. I wouldn’t know where to look it up. In the forest, they have tree sitters. When it comes time to destroy this dam I think I will camp out on a platform hanging from a rope on the face of the dam. Not a tree sitter but a dam sitter.
Mendocino County:
-Est 17,470 acres of vineyards
-200 acres of vineyards averages around 67 acre feet of water (AFW) annually
– Over 5800 AFW annually consumed just to the vineyards
-Cannabis water consumption is 1.4 AFW per acre of crop
-Mendocino has many more unlicensed farms than licensed farms, so lets say 7K acres of cannabis which I think is conservative. 7Kx 1.4 = 9.8K acre feet of water consumed
Vineyards and Cannabis water consumption annually is just shy of 16K AFW.
-City of Ukiah consumes about 3k AFW annually (ignoring the water recycling system which offsets 1k AFW)
-Willits, in 2020, consumed 718 AFW annually.
-Ukiah water serves around 22K people
-Willits water serves an unknown amount per internet research. (best guest maybe 5K people)
-27K people between Ukiah and Willits water utility use .14 AFW annually per person (ignoring the water recycling system) (with water recycling .10 AFW per person annually) (3718afw/27Kpop)&(2718afw/27kpop)
-Mendocino harbors around 350 Vineyard owners = 16.57 AFW consumed (per vineyard owner) 5800AFW/350pop
-Mendocino harbors 500 legal cannabis growers
-Mendocino harbors an unknown amount of black market growers but lets just say there are 2K black market growers. (some legal growers may also be commingled with black market grows, which is somewhat common) (9800afw/2500pop) = 3.92 acre feet of water per cannabis owner (this number is likely higher given some people may be over counted for doing both black and legal market cannabis)
Annual Use:
City of Ukiah and Willits Urban User: .14 AFW (ignoring recycled water) per person
Cannabis Farmer User: 3.92 AFW per owner
Vineyard Farmer User: 16.57 AFW per owner
Bradley, lets not group everyone together as if we are all equally going to be affected by this Dam decommissioning.
The 600,000 number are Sonoma County Water Agency customers – and that water could be said to come mostly from Lake Sonoma – completed in 1983 – now 40yrs of improved resiliency.
If you really wring water rights from SCWA then yes some of it comes, via 65+ miles of Russian River, through the Alexander Valley farming region from Lake Mendocino. SCWA customers are reducing their water usage, less waste and leakage – SCWA transmission last year was 44,530acre Feet and all the customers have ground water alternatives. Lake Sonoma water supply capacity is 245,000AF, Lake Mendocino water supply capacity is 122,500AF.
Now Cloverdale (9000people?) uses 1200AF, though can suck up a lot of water passing by on the Russian River / Big Sulfur Creek as it has pre-1914 water rights.
Similarly Ukiah (16,000people?) uses 3,030AF, and then looking at the local geology has a projected underground water storage estimated to be 400,000AF. (Ukiah Journal Sean White May 11, 2021) – compare that against Lake Pillsbury’s 80,600AF.
So looking at the local geology, its good to plan for water supply resiliency, storing it in the ground, ensuring the basins are well filled in good years by the winter rains. Yeah for the Ground Water Basin studies and monitoring, they can be part of a portfolio of long term storage that doesn’t evaporate!.
Yeah, I did read in one report that they are concerned because it could be a problem in a 600 (700? I can’t remember) year event earthquake. And if you drink too much water you can die. This is not a REALISTIC reason to be decommissioning the project. More BS excuses that those wanting to push it through make to justify destroying the established ecosystems that have developed since the dams and diversion were put into place.
Amen
Yes, it is an excuse to destroy the dam and our way of life: farming, tourism, the water we drink. One wonders why are they pushing this so hard? PG&E is one reason. Why are the politicians pushing for it?
Putting those who depend on water at serious risk of drought and no water.
This earth quake analogy clearly plays to the narrative for dam removal. Comparing the Loma Prieta quake that lies almost on top of the San Andreas to the Bartlett Springs which is on the fringe of the SF Zone intentionally misrepresents the likely hood of failure. There have been many earth quakes in the Lake Pillsbury region. In the 1970’s Scott Dam under went a massive dam stabilization project. There is more concrete poured below the dam than there is above connecting it to the main rock base footing. I also don’t believe you can build a dam in California that would not be threatened by an EARTH QUAKE! If in fact the dam needs more stabilization then so be it. Lets do it…… I agree the Dept. of Interior, USFS could be the answer. Send your letters to them, I have.
I agree with that 100%
This is trash news, we have not seen the pg&e study.
You can not trust PG&E studies at all. They are entirely driven by profit. Their “experts” are bought and paid for. They are paid to provide the answers that PG&E desires. To support their agenda. And profit margin. They want to tear this damn down because they can’t make money off it anymore. The excuse they are using is that it is seismically unsafe. That is a lie that the dam is unsafe. PG&E is bleeding money because of lawsuits and they’re just pinching pennies except this penny will cost a half $1 billion.
A major earthquake could also destroy Ukiah. Scare tactics and hyperbole by Congressman Huffman’s toadying sychophants.
Yes exactly. It’s Huffman leftist agenda. Just like the meteor analogy I could lay awake all night not sleeping worrying about dam failure and meteors crashing through my roof. Or I could have a heart attack or a stroke in the middle of the night. I sleep like a baby and don’t worry about these things. I’ve climbed all over that damn back in the 80s and 90s it’s massive and it’s thick and it has already stood the test of time. If an earthquake comes along strong enough to tear out Scot damn then Lake Mendocino will go also and so many other reservoirs. You cannot lay awake at night worrying about stuff like that. The geologist worrying about earthquakes. It’s just a red herring.
https://www.krisweb.com/biblio/russian_mcwa_chocholak_1992_russianhistory.pdf
Absolutely fascinating that our human actions have caused the river to entrench so much into the valley floor exactly because the dams have held back sediment. Lessening the Valley’s fertility and lowering the water table all in one.
Yep too bad we can’t pick up and move Ukiah somewhere else.
That’s amazing that the reason there aren’t a bunch of dumps around Ukiah is because a group of women got together and said enough of this garbage are ya’ll animals. And now we have low gap park. You’re welcome.
Praise women
Es sphincter says what
Pg and E doesn’t want the dam cause this could happen and they’re still paying us out from the last disaster they created ; the 2017 fires. Has everyone forgotten how they wouldn’t clear some simple branches away from their PotterValley power station? Hence a disaster they thought impossible happened. They’re not taking an even bigger chance with an old faulty and economically obsolete dam. They see a liability and they’re getting away.
You all got hooked on pg and e’s Pillsbury playground. Your nostalgia is for your childhoods, not the lake.
I grew up at Pillsbury, there was always alot of drunks in boats, cops showing up to the campground, bullet casings everywhere. One time we came up on a past hunting camp and there where at least 20 dear legs just left rotting around the fire. Ah yes, those were the days.
Take out the dam so humans can adjust on our own terms, not when a disaster strikes and we’re forced to!
Drink water not wine!!
I feel bad for farming families way of life, but they’re growing wine and buying more land with their money and hiring cheap immigrant labor in substandard housing!! They’re not supplying local non college bound kids with jobs or growing wheat and potatoes. When is the right wing gonna admit that about all farming in the US? It runs on the immigrants they’re claiming to want out.
That’s why this whole story is such hypocritical b.s on the farmers end. So much further than water. The farmers are stressing cause suddenly their heredity doesn’t matter, suddenly indigenous heredity matters. See, we’ve got to get past heredity and start thinking about what we’re passing on. This is the shift of our time.
The most poignant point. Amen
Huffman, FOER and Pg&E have saved the recent seismic bugaboo until now as part of a really well planned out scheme to get their way.
At least they have stopped claiming an imminent threat to Potter Valley itself from the flood that a Scott Dam failure would cause. That claim used to be part of their misinformation tactics.
Their way being not having to pay for an obsolete structure. When are people going to learn that instead of maintaining a dam we can maintain a river?