Another California Water Crisis

It’s no secret that a vast amount of American infrastructure is in great need of upgrades, repairs or replacements. The repairs that are desperately needed will come, and they will come in one of two ways. Either proactive repairs can be made when problems are first discovered, or repairs can be made at considerably greater cost after catastrophic failures have occurred. As was the case with the I-35 bridge collapse in Minnesota, we often pay in lives as well. Part of the problem is that infrastructure isn’t very exciting or newsworthy to many people outside of the civil engineering community which leads to complacency and apathy. As a result, it’s likely that you may not have heard about the latest struggle currently playing out in California even though it involves the largest dam in the United States and its potential failure.

Surprisingly enough, the largest dam in the US isn’t the famous Hoover Dam but the Oroville Dam at the base of the Sierra Nevada mountain range in California. At 235 meters, it is almost 15 meters taller than the Hoover Dam. It can store over four cubic kilometers of water but whether or not it will keep storing that water into the future is currently under question. In February of this year during a flood control operation damage was observed on the dam’s spillway where a massive hole had formed which only got larger as the dam was forced to continue releasing water. The hole quickly grew, and the floodwaters eroded much of the lower half of the spillway embankment, forming a canyon.

Spillway damage as seen on 2/27/17 [via Dale Kolke/CA Dept. of Water Resources]
The greater threat to the dam itself wasn’t simply the damage to the main spillway, but the use of the dam’s emergency spillway. It was used for the first time after the main spillway had to be shut down, but once the water started flowing, the amount of erosion behind the emergency spillway was much higher than anticipated. It was thought at one point that the erosion might undermine the strength of the dam itself which would have let loose a 9-meter-high wall of water down the Feather River, destroying many communities in its path. An evacuation order was issued for residents of the area during these series of events, but luckily the main spillway stabilized (although heavily damaged) and was able to allow Lake Oroville to drain enough to alleviate concerns of a total dam failure. The snowmelt in the Sierra Nevada isn’t finished yet, however, so the dam and the engineers working on it aren’t quite out of the woods.

As of this writing, the damaged main spillway has just been reopened and is expected to handle 35,000 cubic feet per second for a few weeks. Engineers have made great strides to make sure that the spillway can handle the outflow and have been given some gifts from the surrounding topology to make that a reality. First, rather than the entire mountainside eroding beneath the damaged concrete spillway, a large “splash pool” formed that serves to dissipate much of the energy of the moving water before flowing through the newly-created canyon. This has helped keep erosion to a minimum. Oddly enough, increasing the amount of water flowing down the spillway decreases the amount of erosion (to a point) because it lands further down the mountainside, limiting erosion under the good section of spillway further up. The addition of shotcrete to this area has also helped to stabilize the spillway. Additionally, the erosion towards the bottom of the spillway formed a canyon after the water scoured the landscape down to bare bedrock. This rock is a lot less prone to erosion and has thus created a relatively working spillway that bypasses the bottom half of the man-made spillway.

Workers repair the massive hole that formed in the Glen Canyon Dam’s main spillway tunnel as a result of cavitation.

While the investigation as to the cause is ongoing, there have been a few other American dams that have had similar spillway issues that engineers have had to learn from. The most notable was at Glen Canyon Dam in Arizona where, in the early 1980s, cavitation issues in the main spillway tunnel led to the formation of a giant hole inside the tunnel that was rapidly eroding the canyon walls and threatening the integrity of the dam itself. Cavitation is a phenomenon where changing pressure in a liquid can create bubbles which later collapse under higher pressure and generate a damaging shockwave.

The Glen Canyon Dam was constructed between 1956 and 1966 before the invention of “air slots” that prevent damage caused by cavitation in high-velocity flows. The repairs to Glen Canyon Dam included these air slots and the dam has been operational since. Potential repairs to the Oroville main spillway include similar designs to mitigate cavitation, but further investigation is needed. This will likely not be completed anytime soon, though, as the main spillway is required to operate until the risk of flooding has passed after the spring snowmelt in the Sierra Nevada has stopped.

Future repairs include plans to reinforce the rear of the emergency spillway. During its first-ever use this year, erosion behind the emergency spillway was much more rapid than predicted, also raising concerns that the dam may fail. This risk has largely been mitigated for now, but it is something that will need to be addressed in the immediate future. Transmission lines that run across the emergency spillway will likely need to be repaired as they may have experienced foundation issues from the rapid erosion.

While repairs are ongoing, its likely that this dam will be on the radar for the foreseeable future. Unfortunately, this isn’t an isolated problem for dams or with infrastructure in general. Most of the big-ticket infrastructure items were built decades (or, almost a century) ago and have been minimally maintained in the interim. The future of this infrastructure, and the people who depend on it, rests on the shoulders of engineers willing to try new and innovative solutions to keep it all together.

You can keep up with the issues at Oroville Dam via the California Department of Water Resources, the organization responsible for the upkeep of the dam, or via some fantastic reporting by Juan Browne via YouTube. If there is another piece of infrastructure near you that isn’t receiving the attention it deserves, tell us about it in the comments or email the author directly at

Featured image by Dale Kolke / California Department of Water Resources (California Department of Water Resources) [Public domain], via Wikimedia Commons

69 thoughts on “Another California Water Crisis

  1. That’s a lot of water.

    In the main pic, it looks like the water is climbing quite high up the walls of the spillway in the in-tact section. Why is it doing that? You may have to zoom in to see it.

    1. Those are drain outlets in the side walls. Drainage pipes under the spillway angle out to the edges, then turn into the walls (still going downhill, but not as steep an angle as the spillway itself) and then drain back into the spillway.

      One or two of these drains being clogged probably had a significant role in the spillway failure. If you’re interested in the subject I suggest going back and watching all of the blancolirio (Juan Browne) videos on youtube

        1. So why do many your DOTs require it to be added to all new concrete roads, bridges etc? It saves money and lasts a whole lot longer. It is specially used in industries with high abrasive moving equipment in heavy industry yards.

        1. Your answer makes sense, the other one seems to be pushing the use of more concrete and is totally unconcerned by its environmental costs. I am glad I chose not to have any kids, the human populations will live miserable existences once environmental degradation progresses. The Global heating has now taken on a life of its own and can only be reversed by a nuclear war or by a major meteorite impact. We need a lot of dust in the upper atmosphere. Of cource that too is a problem think Silicoses.

  2. The biggest issues for infrastructure repairs are funding and bureaucracy. Certain people would rather have their tax dollars go to the EPA instead of funding the “power company” since that’s supporting the “1%” (Apparently people think that CEOs are the sole employees of large companies). The EPA then turns around and uses the money to push and enforce laws which make it a nightmare to make any changes, upgrades, or repairs to these facilities. This leaves facility operators (even those which are essentially government owned and operated) with no option but to cross fingers and hope for the best. Instead of saving the planet, maybe we should worry about the people living on it… Especially those downstream of dams. Note: I am talking about hydroelectric dams here, of which not all dams are, but it illustrates the point.

    1. Could you please clarify all that a little bit – maybe with some sources/references…

      While “power companies” may have an incentive to keep their hydroelectric dams properly maintained and working, they are still profit oriented aren’t they?
      I think they would only spend the required bare minimum to keep them working.

      I’m by no means knowledgeable on this topic (especially concerning the USA) but i still recommend this LWT YT-Video (if only for the comedy):

    2. If I remember my information correctly, the dam is owned by the State of California (not by any power company), and though there have been reports of damage and requests for funding repairs for years, CA has had a drought for many years too. Obviously, no politician is going to vote in favor of expensive repairs to a dam that doesn’t have any water behind it.

      1. Part of the problem is the classification of the Oroville dam was changed. Originally its primary purpose was flood control, with storage and power generation secondary. Thus it wasn’t kept more than around 50% full before spring.

        As California’s energy policies failed to allow for expansion and addition of more power generation, by any means other than “green” and erratic wind and solar, Oroville was reclassified as a primary storage dam. No problem – until a record precipitation year comes along and nobody makes the call to drain the reservoir to make room for the massive amount of water to come down from the mountains.

        Meanwhile, concerns raised about the condition of the rarely used main spillway, and never used emergency spillway fall on deaf ears in California’s government. Not even the very anti-dam Sierra Club’s lawsuit to get the State to make repairs raises any concern.

        President Trump asked all the Governors to have lists drawn up of their State’s most urgent infrastructure needs. California’s list did not include the Oroville dam.

        If they’d called up Line-X and said “Have we got a project for you.” and had it sprayed with a heavy coat of polyurethane truck bed liner, the spillway likely wouldn’t have failed. That stuff is used to prevent concrete walls from being shattered by bombs.

          1. The only way to test the emergency spillway is to allow the lake to fill so high that it overtops the dam. At that point you lose a lot of control over how much water you release into the lower river system.

            You would anger a lot of people testing an emergency spillway followed by the fast dumping of water to get the lake level back to safe levels.

            One of the big problems now faced by the downstream communities is that the main spillway cannot be “throttled” and can only operate between 35 and 40k cfs or at 0 cfs. The quick changes in flow on the lower Feather river have been causing massive failures of river embankments and lots of damage for farmers.

          2. @ThisGuy:
            Oh, so the emergency spillway is just there in case the lake is overfilled? I would’ve expected it to be of the same functionality as the primary spillway, to be used when there is an issue with said primary spillway.

          3. @Phrewfuf,

            The emergency spillway is really only there as a last resort spillway for when the main spillway fails, to stop water overtopping the dam which would cause it to fail. It’s a last resort without any gate mechanisms that can fail.

    3. Sure, it’s the EPA’s $8B budget to blame for this failure. If only those pesky hippies didn’t get any funding all the US infrastructure would be pristine.
      There’s a $4T dollar pie to slice up. No one program is at fault.

    4. I find it strange to blame mainly the EPA for the infrastructure problem. As a German I’m certainly not an expert on U.S. bureaucracy but to me the elephant in the room is infrastructure spending: Germany for instance spends roughly 3% of its GDP (and even we have to do better) while the U.S. is spending below 1%. As always, you get what you pay for (0% taxes= 0% public infrastructure).

      1. American politics, for the past 40 years, has relied on demonization of environmentalism to keep the taxpayers divided while the political and business classes loot the treasury of tax dollars.

        In reality, the least effective political group in the USA during that period has been environmentalists. They have literally accomplished nothing since the Clean Air and Water acts, and are blamed for all sorts of things they did not in any sense do, such as preventing the development of safe nuclear power and preventing the development of clean coal technology, along with many other ridiculous allegations.

        However, the German Green Party has provided an inspiration to the common people of the USA who almost universally understand that we can’t pump trillions of tons of pollution into the air and water and then pretend it won’t have any effect. We are opposed by every industry and every political party, but the regular folks are rising.

        1. lmao “clean coal” yeaaahhhhhh… That is a platform for liberal politicians to plead for votes from blue collar workers by keeping their jobs. Outside of Washington, no one believes that garbage.

      2. It is rarely as simple as the EPA. You would have federal EPA, California EPA, Fish and Wildlife, Army Corps of Engineers, The Nature Conservancy, Sierra Club, Farmers and local officials all at the table. It’s a lot of things to balance and everything has to go right. Everyone has good intentions but simple human nature can get in the way.

    5. Your right! We should totally disband the EPA because they don’t protect water. Or air or anything you actually NEED to survive but rather exacerbate first world problems by making them slighting more expensive so they don’t cost more lives.

      Or you could look at history and see that the Clean Air Act actually prevents your sewer company from dumping raw waste in your drinking water source!. Or prevents fine particles of soot from industry from clogging your lungs. You know those pesky environmentalists just trying to get in the way of a dollar.

      Go look at Iron Gate dam, an earth dam past its life expectancy, that creates a huge shallow pool of toxic green algae and has killed a number of animals because of all of the agricultural runoff that it captures. Not only that but since it now houses endangered species in that same water created by the dam, it’s now a nightmare to keep and to remove due to regulations on both sides of that equation. Scottish power purchased the dam only to sell it to Warren Buffett when they realized the total crap storm they had on their hands.

      Did you know FERC has yet to ever prevent an operator from renewing their license?

  3. “As of this writing, the damaged main spillway has just been reopened and is expected to handle 35,000 cubic feet per second for a few weeks”

    I’m guessing you started researching this piece a few weeks ago, because that’s when they started releasing at 35k cfs. As of today they’re at the minimal reservoir level where they can use the spillway (835ft) and will probably be shutting it off within the day, IMO. You can see live-ish data here:

    1. +1

      As a Northern California native that lives about an hour from the Dam, it’s easy to see the mud in this HaD article. But hey, this is the internet, factual data just wastes characters.

        1. Well Kevin, you are already spending more than everyone else combined, “to kill them”. So maybe, just maybe, some of this money could be spent on dams, hospitals and roads? And debt. And NASA, please.

          1. Well, since we are almost out of bombs in fighting ISIS, do you recommend that we just say “Sorry guys, we can’t bomb you any more. Go ahead and try to behead more innocent people.” as an alternative?

            I am not against considering reducing what we spend. You just gave the impression that we should not spend anything.

          2. out of bombs?

            whatever you are smoking, i want some, plenty of bombs left over from previous wars and yes those are used, any JDAM that is dropped is leftovers from yesteryear and that is just for starters.

        2. In an article about preventative maintenance Vs fixing it after it breaks, we could of couse NOT antagonised one third of of the occupants of the planet, then they might not want to kill us.
          It’s just a thought.

    1. The main problem with government funding for the LAST 40 YEARS is the simple fact that government bureaucracy and administration has become the single highest ‘muncher’ of our money. Yes, there is a load of ‘pork’ spending – but increased government agencies(Homeland, anyone?) and poor direction of the agencies we already had have increased government payroll and internal costs(office supplies anyone?) far beyond what we really need – IF the government was run efficiently(which is NASTY word to entrenched bureaucrats who more or less have a ‘tenure’ so long as they cause no problems at work).

  4. To this day, it still fascinates me how powerful can water erosion be…
    As equally fascinating is the level of neglect on operating something as important and potentially destructive as a dam. I’d understand powerlines, sewers or roads, because when that fails, there’s usually a way do deal with it until it’s repaired, but when a dam catastrophically fails, it’s armagedon for anything close downstream…

    1. Here is a good way to think of water erosion. Think about what can be done(destructive-wise) with a sand-blaster(if you have questions, consult youtube – there ARE videos). Water erosion is simply natures’ version of sandblasting, only done mega-sized. What it might take wind erosion millions of years to accomplish, water erosion can accomplish in hundreds(or thousands) of YEARS, depending on the water force and what is being eroded.
      Devil’s Tower(used in Close Encounters of the Third Kind) likely took millions of years to erode from the extinct volcano-mountain it once was to the simple form it now has of the volcano’s hidden ‘throat’. If it had been in the middle of the Grand Canyon during the Canyon’s really active days, the erosion likely would have taken around a thousand years or so – that’s one entire MOUNTAIN’S soil and loose rock coverage REMOVED.

      1. Consider a water cutter… put a hole through inch thick steel in a few seconds. Water (with sand), a frightfully erosive combination!

        Makes a sand-blaster look gentle enough to clean your teeth with.

  5. 25 years in the maintenance industry (commercial and industrial) taught me that management is usually to blame. To the bean counters, maintenance is just an expense to be reduced or removed entirely. They don’t understand that it’s actually an investment. I’ve worked in places where they literally tried to cut the maintenance budget by 20% every year. The results were predictably bad, which we in the maintenance department were then blamed for. What fun…

    1. You see the same thing in private industry. I did some work for long running successful heavy industry, player when a multinational took over and the instruction came down, no more maintenance, only patch jobs. Sure for the first couple of years the profits looked good. bosses got their bonuses and then the long term impact started.

      Its like paying a mechanic for spending as little as possible to maintain your car. Simple, don’t do any fluid or filter changes, make a killing, and leave the business before the chickens come home to roost.

      1. Back in the ’70’s I was a car washer for a Ford dealer. They took a trade-in with a 100,000+ miles. (a LOT of mileage for an American car back then) The car looked great, when the dealer called the owner regarding the previous oil change, he was told it had never been done!

      1. Bean counters (accountants) or management? It has been taught in Business courses for decades that maintenance and customer service are anti-profit as opposed to “value added”. True accountants know the value and depreciation of equipment and want to minimize losses over the long and short term.
        Full disclosure: I am not an accountant, but have 4 brothers and a brother-in-law who are.

    2. It’s not a public sector or private sector thing. It’s really not even a bureaucracy thing. It’s the fact that most people (especially the most ‘promotable’ people) tend to think and act to further short term interests while ignoring long term.

    3. How about “saving money” in the maintenance budget by not reducing the budget, but by not doing the maintenance? The money is there to use but by not using it, it makes the overall budget “balanced” and other money “free” to be spent on other things.

      The Meridian, ID school district did that once, accumulated over $2 million in their maintenance fund while letting the schools fall apart – then whined they just had to have more property tax levies to replace the buildings.

      Meanwhile, there are the “Ivy League” colleges and universities, and many schools in Europe that are in buildings a century or more old – and kept in good condition.

  6. For those interested in dam engineering (no pun intended) and the types of challenges facing the people that run them in this sort of situation, I recommend the fictional novel “Wet Desert” by Gary Hansen. It’s about a terrorist attack against the Glen Canyon dam and others on the Colorado River. The book is very well researched and makes it clear just how bad things can get when a major dam is breached.

    I have no affiliation with the author or anyone that created or distributes the novel, I just really like it (have read it twice).

  7. The question has been raised whether the main spillway at the Oroville dam was built to spec, or whether something happened like rebar being laid, inspected, then removed for reuse before the concrete was poured.

  8. Hoover Dam’s spillways have only been used twice. They were tested when the dam was completed in 1941. Cavitation tore chunks out of them. They were repaired.

    The 1983 flood required using them and again chunks got ripped out. They were relined with harder concrete, polished smooth. Flip buckets and aerators were added, reducing their capacity and hopefully fixing cavitation problems – but none of that has yet been tested. They’ll wait for another flood year to see if they fail for the 3rd time.

  9. I live in Yuba City. Sometimes work in Orville and did not evacuate. Also seriously, lived in mpls when the bridge collapsed. Please don’t get the wrong idea. Just pointing out. Also another bridge collapsed on hwy 1 recently.

  10. Why do we continue to try to contain nature then complain we’re f’ing up the planet? Let nature be, don’t build your house in a flood plain, don’t build your house under sea-level near the ocean, is it really that hard?

    1. Don’t drink the fresh water the dams prevent from flowing into the ocean, and don’t eat the food it allows us to grow.
      Are you willing to die to protect nature?
      What is needed is not killing most humans to protect nature but to increase our technology to the point where humans have less impact, fusion powered desalination and under ground hydroponics would solve the above problems without killing humans.

  11. this is what happens when your state has decided that its priorities are towards consumption and entitlement instead of infrastructure. Fed problems aside, the State has obtained, allocated, and reallocated funds for roads and infrastructure that always ended up somewhere “more important”.

    Dams don’t vote apparently. But Sanctuary City programs and official orders to deny cooperation with Federal officers in enforcement of long standing legal orders, well, it’s important to keep up the “dream”. Shunting over millions of ARRA money into social services programs and landscaping projects along highways instead of the highways themselves, well, our roads are simply the more visible signs of failure.

    But people who understand infrastructure and care about sacrificing short term personal gratification for long term functional capability are vastly outnumbered by those who care about themselves first and then move elsewhere when there’s nothing left, when it comes to the polls.

    Add to it people who think telecom is the only *resource* to care about because that’s where they make their gigadollars, and the State falls even farther downhill

  12. Interesting that they “had” to use the spillway – unless this photo has been doctored, the dam is SIGNIFICANTLY below holding capacity (the tideline is *way* above the water line), and yet the spillway is running fairly well, even though it is well below (its’ undamaged) capacity.


    1. They are lowering it as much as they can to allow time to make repairs. Ideally till November. There is still snow pack that will melt, and future rainstorms that will fill it back up. The power plant output may not be able to keep up with those inflows without the buffer the lowered reservoir allows.

  13. I laughed at Google’s recent “10 years of Google Earth” where they attempted to show the effects of human’s on the world.

    They showed all these areas around California where the lakes and water ways dried up, Brazilian rain forests cleared, etc.

    My amusement came from them acting like they had nothing to do with it.

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