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[Oroville Dam] Please Stop Raining

AegisAegis Not Quite TorontoRegistered User regular
edited February 2017 in Debate and/or Discourse
0AAln92.jpg
(Helpful overview of the Dam and its geographic relation in Califnornia by Vox)

Oroville Dam is the tallest dam in the United States, measuring 770 ft tall (44 ft taller than the Hoover Dam) and containing a water supply (Lake Orville) of over 3.5 million acre-feet (4.4 km3). In addition to providing hydroelectric power, the resevoir of Lake Orville provides water for over 25 million people and is a key component of the Central Valley Project. Conceived of during the New Deal era, the CVP is a federal water management program to provide irrigation to California's Central Valley. The Dam itself was started in 1961 with work completing and the dam coming into operation in 1968.

Now, normal operation of the Oroville Dam includes the operation of a spillway, a mechanism by which water can be released from the resevoir to lower the level of the Dam and ensure it doesn't overfill during periods of lots of precipitation. This is what the spillway should look like when in operation:

maxresdefault.jpg

This, meanwhile, is the current state of the spillway (as of Friday or this weekend):
LHp1eoE.jpg

There should not be a gigantic sinkhole there.

However, the Dam does have a backup plan in case the main spillway has a problem. That would be the Emergency Spillway, which is basically a fancy way of saying "letting the Dam overflow a part a little ways up from the regular spillway and flow down the hillside until it eventually hits the Feather River." For the first time in the history of the Oroville Dam, the California Department of Water Resources used the Emergency Spillway this weekend:



Unfortunately, they put a stop to this not long after using it. Turns out, there were concerns regarding erosion at the base of the earth near the Emergency Spillway and they did not want to run the risk that the retaining wall that makes up said Emergency Spillway would erode and collapse, releasing a metric fuckton of water at once down the hill. Because of this new problem to an already serious issue facing the main Spillway, an evacuation order was issued for 188,000 people downstream:
Immediate evacuation from the low levels of Oroville areas downstream is ordered. From Oroville to Gridley...low level areas around the feather river will experience rapid river rises.This is not a Drill. This is not a Drill. Repeat this is not a drill................Move to higher ground now. Act quickly to protect your life.

As of Monday's press conference, this evacuation order is still in effect and with rain still projected for the coming week, it's unknown as of yet when they can return.

This would all be problematic, and not necessarily be a crisis, except for the fact that it will not stop raining in California. Here are the current resevoir levels throughout California:
AVlLU2q.jpg

So, Lake Orville's been sitting at 150% of historical average and bobbing between 95 and 101% capacity. Current weather expectations for the upcoming week: more rain. What this means for the situation is that notwithstanding said hole in the spillway, the Dam itself can't not run water down the spillway. Officials need to run water down the damaged spillway in order to reduce the Lake's current capacity not only because it is historically overfull, but also to make room for future rain that just won't stop falling. This, naturally makes the sinkhole problem worse, as water continues to extend the size of the hole (which when it first appeared, only covered half of the spillway and not an entire chunk as well as half the hill on either side that you see in the picture above). Edit: Here's a nice side-by-side comparison of what's happening as they have to run water over it:
lIgWh3n.jpg

In terms of what could be done, the press conference that was held today (an update on the evacuation and the current status of the Dam and situation in general) had multiple reporters asking questions of whether officials knew about a 2005 request by environmental groups, including the Sierra Club, that suggested the spillway be armoured with Concrete over fears of its integrity. Given the current massive sinkhole spreading across the spillway, expect to hear more of this report as the crisis develops, and in general of the potential problems with critical infrastructure this old not receiving sufficient maintenance attention.

Useful articles on the matter:
http://www.vox.com/science-and-health/2017/2/13/14598042/oroville-dam-flood-evacuation
http://www.forbes.com/sites/marshallshepherd/2017/02/13/the-science-behind-why-the-u-ss-tallest-dam-is-causing-major-evacuations/#665d24d54fac

We'll see how long this blog lasts
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  • JragghenJragghen Registered User regular
    Reddit live has a thread going for this for people who want up to date info

    https://www.reddit.com/live/yfixu0gbq4ub/



    Yesterday's 10 day precipitation model starting Thursday.

    Haven't read the details yet, but this thread has impressive pictures of the erosion.

    AegisshrykeUnlucky
  • SleepSleep Registered User regular
    Just so I've got this straight, California went from totally drought ridden, trying to figure out how to protect what little water they have, to completely over stocked with water to a destructive degree?

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  • FeralFeral MEMETICHARIZARD along with you if I get drunk well I know I'm gonna be gonna be the man whoRegistered User regular
    edited February 2017
    "Waaaaahhhhh we're in a drought!"
    "Waaaaahhhhhhhh please stop raining!"

    You Californians are never happy.

    (I'm kidding BTW, I lost most of my childhood to the Tuolumne River flood in 1997. I know how awful they can be.)

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  • dispatch.odispatch.o Registered User regular
    edited February 2017
    I'm from Chico. My mom still lives there. This is pretty intense stuff. She has friends in Oroville and still works there. Silver Dollar Fairgrounds seems to be the triage/shelter area for evacuees according to her and the news.

    Northern California has its own issues, but I really hope they devote some funds to an area other than Sacramento, San Francisco and LA sometime for infrastructure.


    Edit: There have been a handful of floods in my lifetime in the area. People always laugh about how the stupid Californians always have a drought and then mudslides and apocalypse stage rains. The state is very large and while central and southern California need the water, the north and mountain range areas are the places that have to deal with all of the storage and capture of that water. The reservoirs can only capture and hold so much water at a time. Lake Shasta still looks (as of a few months ago) like a mud puddle, just because torrential rains fall and destroy things every few years, doesn't mean that the Sacramento River and Los Angeles County wont be in a drought again in a year.

    They've been talking about investing in the states ability to capture and maintain water stores since I was a little kid. I guess water isn't a sexy thing to spend money on?

    dispatch.o on
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  • AegisAegis Not Quite TorontoRegistered User regular
    edited February 2017
    Jragghen's thread link does provide some more context to the issue facing the damn:

    Influx into the resevoir (Feb 9th): 130,000 cfps (cubic feet per second)
    When the spillway failed and the hole appeared: 50,000 cfps (outflow)
    When they were running the spillway even with the hole: ~100,000 cfps

    The press conference today noted that at one point they were running the spillway at 150,000 cfps to bring the 130,000 cfps influx under control (it's dropped from that to 80,000), and that the maximum design for the spillway was around 160,000 cfps. I believe since this past weekend, influx has calmed down slightly (until it rains starting Wednesday), but this is the issue they're facing: there's too much water coming into the resevoir and now they really don't want to run the Spillway at remotely close to what they need to because it's making that hole problem so much worse.

    Edit: The hydroelectric plant and the "fish bypass" also collectively add another ~20,000 cfps outflow.

    Aegis on
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  • FeralFeral MEMETICHARIZARD along with you if I get drunk well I know I'm gonna be gonna be the man whoRegistered User regular
    Sleep wrote: »
    Just so I've got this straight, California went from totally drought ridden, trying to figure out how to protect what little water they have, to completely over stocked with water to a destructive degree?

    Kind of.

    The problem is three-fold, and it's really mostly #3:

    1) Northern California finally got a good rainy season! Yay!
    2) The main spillway (which is where excess water gets routed) developed a crater. Boo! Well, these things happen, which is why we have an auxiliary spillway...
    3)... but in this case, not only has the auxiliary spillway never been used before in the entire history of the dam, but it's barely been inspected. So now the auxiliary spillway has failed, largely due to neglect.

    every person who doesn't like an acquired taste always seems to think everyone who likes it is faking it. it should be an official fallacy.
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  • shrykeshryke Member of the Beast Registered User regular
    Sleep wrote: »
    Just so I've got this straight, California went from totally drought ridden, trying to figure out how to protect what little water they have, to completely over stocked with water to a destructive degree?

    Someone passed California that fucking monkey's paw that's been going around.

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  • dispatch.odispatch.o Registered User regular
    Also as a note, what would be considered a city of substantial size in other states is considered barely a town in California. Chico, CA has almost 90,000 people living in it. Butte County is around 220,000.

    Just under half the population of all of Wyoming lives in one small county in California. This is a big deal.

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  • AegisAegis Not Quite TorontoRegistered User regular
    Here's also some perspective on just how big the sinkhole is that's in the Spillway:

    wbycJQN.jpg

    We'll see how long this blog lasts
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  • JragghenJragghen Registered User regular
    This should be a general wake up call for infrastructure the country over.

    It won't be. :-(

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  • DarkPrimusDarkPrimus premium Registered User regular
    Jragghen wrote: »
    This should be a general wake up call for infrastructure the country over.

    It won't be. :-(

    Trump said he wanted to be all about infrastructure projects!

    Buuuut then he found out that infrastructure projects cost money...

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  • SleepSleep Registered User regular
    dispatch.o wrote: »
    I'm from Chico. My mom still lives there. This is pretty intense stuff. She has friends in Oroville and still works there. Silver Dollar Fairgrounds seems to be the triage/shelter area for evacuees according to her and the news.

    Northern California has its own issues, but I really hope they devote some funds to an area other than Sacramento, San Francisco and LA sometime for infrastructure.


    Edit: There have been a handful of floods in my lifetime in the area. People always laugh about how the stupid Californians always have a drought and then mudslides and apocalypse stage rains. The state is very large and while central and southern California need the water, the north and mountain range areas are the places that have to deal with all of the storage and capture of that water. The reservoirs can only capture and hold so much water at a time. Lake Shasta still looks (as of a few months ago) like a mud puddle, just because torrential rains fall and destroy things every few years, doesn't mean that the Sacramento River and Los Angeles County wont be in a drought again in a year.

    They've been talking about investing in the states ability to capture and maintain water stores since I was a little kid. I guess water isn't a sexy thing to spend money on?

    Infrastructure never is

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  • spool32spool32 Contrary Library Registered User regular
    Why hasn't the hole been fixed?

    I feel like if you built the whole dam in 7 years, a hole ought not take all that long.

    Doodmann
  • dispatch.odispatch.o Registered User regular
    spool32 wrote: »
    Why hasn't the hole been fixed?

    I feel like if you built the whole dam in 7 years, a hole ought not take all that long.

    I can only guess, but they've been forced to use the spillway even with the hole in it because it was the only way to prevent failure of the dam. This isn't a long running problem that has been ignored, it's an... oh wow, there's suddenly a sinkhole in the middle of our dam spillway where there wasn't one before.

    I mean yes, it's probably a larger issue of being ignored and neglected over the past 20 years, but that's something every piece of our infrastructure is seeing.

    ShadowhopeSpoitZilla360Giggles_Funsworth
  • SavantSavant Registered User regular
    edited February 2017
    spool32 wrote: »
    Why hasn't the hole been fixed?

    I feel like if you built the whole dam in 7 years, a hole ought not take all that long.

    Someone on a comment thread somewhere said that that spot on the main spillway had been patched up a bit several years ago, but the underlying problem was probably serious enough that they needed to do a major replacement instead of what they did.

    They can't exactly fix it now, as they have too much water in the reservoir that needs to be drained in the short term and the rainy season isn't over yet. This went to full on crisis pretty quickly with the massive amount of rain that region of California has gotten recently.

    Savant on
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  • AegisAegis Not Quite TorontoRegistered User regular
    As of the 10th, the hole in the main spillway was 300 feet wide, 500 feet long, and 45 feet deep. It's grown since then as they've had to run the spillway even with the damage in order to reduce the level of the water behind the dam. Initial estimates on the repair put it at least $100 million.

    For a comparison, the construction of a spillway for the Folsom Dam cost between $900 million and $1 billion, for a modern spillway with twice as much outflow capacity.

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  • PellaeonPellaeon Registered User regular
    edited February 2017
    A few things here. First of all the emergency spillway is passive, essentially the lake gets too full, some starts to spill over the side. So the state didn't start or stop using it per se, it's dictated by the water level in the reservoir. It started releasing water because they didn't release water fast enough via the regular spillway in an attempt to mitigate damage to the hole. Once it started releasing they noted NEW erosion on the emergency spillway side, said "oh shit this thing might give, everyone gtfo." They increased the water from the regular spillway, sinkhole be damned, and now they've gotten the lake below the alternative spillway level, which is why it's "stopped" being used. But if it rains enough and the lake reaches that level again it's going to start going over that emergency spillway again and they won't be able to stop it.

    As to spool32's question, the hole on the main spillway literally appeared within the last week (or so), but as mentioned above they've kept running the main spillway to keep the lake down. Now that there are erosion concerns on the alternative spillway they want to try and drop the lake like 50 feet before the next storms (Wednesday night), so there's been literally no time to fix the main spillway problem. They can work on the emergency spillway right now (current plan: helicopter giant bags of rocks to fill the erosion holes) but even though it's sunny they can't stop water going down the regular spillway if they want to make room in the lake.

    Pellaeon on
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  • MrMisterMrMister Please demonstrate your enthusiasm for e-marking and/or e-assessment with examplesRegistered User regular
    That makes it sound pretty fucked. Just to get a sense of things that I don't otherwise have, and even though it's crass--is there anything like a reasonable over under on avoiding a catastrophic break?

  • AegisAegis Not Quite TorontoRegistered User regular
    There's no threat to the dam itself from what's currently happening. The main evacuation threat centered (and still centres given the amount of work they're doing to drop rocks and shore up) around erosion concerns of the emergency spillway and if that failed, then you'd have a release of a 30 ft depth of resevoir (ie- the height of the emergency spillway), which is hundreds of thousands of acre-feet worth of water that would be released.

    The hole on the main spillway also has been growing, although water's been running clear for a while from what I've seen, meaning most of the erosion of the surrounding hills just around the spillway already hit bedrock.

    We'll see how long this blog lasts
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  • PellaeonPellaeon Registered User regular
    My understanding is the dam itself is fine, the issue is that they've never used the emergency spillway in the history of the dam, and now that they have they have erosion on the outide of the spillway. The emergency spillway is (more or less) a 30 foot wall of concrete at that point. If you erode enough earth in front of the concrete wall there won't be enough force to hold the wall up, and it gives out and 30 feet of water head downstream.

    So, as long as they prevent any further erosion and/or reinforce things on the emergency spillway side then you won't have catastrophic failure. Still have the issue on the main spillway which will need to be addressed but that's not a catastrophic failure level.

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  • JragghenJragghen Registered User regular
    MrMister wrote: »
    That makes it sound pretty fucked. Just to get a sense of things that I don't otherwise have, and even though it's crass--is there anything like a reasonable over under on avoiding a catastrophic break?

    As things stand right now, the dam itself isn't in danger. If the emergency spillway breaches, my understanding is that it would be ~30 feet of water (which is a ton, but small potatoes compared to the rest).

    FeralshrykeGiggles_Funsworth
  • PellaeonPellaeon Registered User regular
    As to the over under on whether they'll be able to fix it there's no way for the layperson to know. They have geotech and soil engineers looking at the current situation and determining what their options are.

    Obviously at the rate of erosion they saw yesterday they thought it was eroding enough to possibly fail "within the hour." A later press conference said it appeared to begin eroding at a slower rate than earlier. With the water not spilling over right now they can see how much erosion they really suffered and how much support they think they currently have, or can add. But we're not going to get that info. For now evacuation is still in effect so they feel there's still a risk of failure.

  • VishNubVishNub Registered User regular
    This thread, on another site has a very good discussion.

    https://www.metabunk.org/oroville-dam-spillway-failure.t8381/page-6

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  • MrMisterMrMister Please demonstrate your enthusiasm for e-marking and/or e-assessment with examplesRegistered User regular
    Thanks guys

  • AthenorAthenor Battle Hardened Optimist The Skies of HiigaraRegistered User regular
    Man, there has to be something they can do to help divert water. I know it's heavy as fuck and this isn't a movie ("Volcano" springs to mind), but if you could divert the water away from the sinkhole, perhaps using air or even water bags, then you should be able to up the outflow. Having it just pour into the sinkhole as it looks like they are doing in those pics just.. ugh. That is not good.

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  • DoodmannDoodmann Registered User regular
    Just for larger scope when is the last time a large damn failed in America? This seems like something we as a nation should be completely ashamed of.

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  • SavantSavant Registered User regular
    Athenor wrote: »
    Man, there has to be something they can do to help divert water. I know it's heavy as fuck and this isn't a movie ("Volcano" springs to mind), but if you could divert the water away from the sinkhole, perhaps using air or even water bags, then you should be able to up the outflow. Having it just pour into the sinkhole as it looks like they are doing in those pics just.. ugh. That is not good.

    The water flow is strong enough to tear quite a bit of that hillside down to bare bedrock. Aside from dropping in the boulders like they are doing for the emergency spillway, I'm not sure how much they can do until they get enough of a breather from the weather to start rebuilding the thing.

    Zilla360Giggles_Funsworth
  • PellaeonPellaeon Registered User regular
    edited February 2017
    Doodmann wrote: »
    Just for larger scope when is the last time a large damn failed in America? This seems like something we as a nation should be completely ashamed of.

    https://www.google.com/amp/www.sfgate.com/news/amp/Biggest-dam-failures-in-U-S-history-10928774.php?client=ms-android-hms-tmobile-us

    Looks like 1972 was a surprise twofer, otherwise it mostly seems to be the late 1800s or early 1900s

    Edit: Also, first hit on my search was from RT, with video, so good to see the motherland is taking notice

    Pellaeon on
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  • shrykeshryke Member of the Beast Registered User regular
    The most amazing thing I've learned from this thread is that your fucking weirdo imperial system has a unit called "acre-feet".

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  • JragghenJragghen Registered User regular
    shryke wrote: »
    The most amazing thing I've learned from this thread is that your fucking weirdo imperial system has a unit called "acre-feet".

    It's 1.25 Megaliters, roughly.

  • JragghenJragghen Registered User regular
    Sleep wrote: »
    Just so I've got this straight, California went from totally drought ridden, trying to figure out how to protect what little water they have, to completely over stocked with water to a destructive degree?

    Going to blow your mind right now.

    Half the state is still in a drought. Like literal "water on the ground" drought, not the long-term "depleted aquifer" drought (which, frankly, the whole state probably still is).

    DoodmannZilla360Giggles_Funsworth
  • ElJeffeElJeffe Moderator, ClubPA mod
    edited February 2017
    Doodmann wrote: »
    Just for larger scope when is the last time a large damn failed in America? This seems like something we as a nation should be completely ashamed of.

    220px-Hard_rain_ver3.jpg

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  • The EnderThe Ender Registered User regular
    I am going to go ahead and ask the stupid question:

    Why can't they just send water down the spillway with the sinkhole in it? Won't the water just fill the sinkhole and then continue down the spillway as normal?

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  • GoumindongGoumindong Registered User regular
    The Ender wrote: »
    I am going to go ahead and ask the stupid question:

    Why can't they just send water down the spillway with the sinkhole in it? Won't the water just fill the sinkhole and then continue down the spillway as normal?

    They are. that is why the hole is getting bigger. The 100,000 cubit feet of water they're running down the spillway per second is eroding the dirt on it.

    If it erodes too much, there might not be enough dirt holding the lake up, and then the dam (effectively) fails.

    wbBv3fj.png
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  • HonkHonk Honk is this poster. Registered User, __BANNED USERS regular
    This seems like a bad situation in the sense that it seems like what's required to solve it solely rests on the rain seizing.

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  • VishNubVishNub Registered User regular
    The main dam is not in danger of failing.

    Current worst case scenario is that the main spillway deteriorates to an unusable state, forcing use of the emergency overflow which is uncontrolled and untested.

    This weekend that occurred and alarming erosion of that structure was observed, suggesting that the aux spillway could fail. That structure has a height of 30ft (assuming it just vanished). More likely some cross section fails and uncontrolled releases in the millions of cfs occur. Levees downstream probably would not be able to cope with that release.

    Which is very bad, but not the nightmare of the main dam failing.

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  • TL DRTL DR Not at all confident in his reflexive opinions of thingsRegistered User regular
    shryke wrote: »
    The most amazing thing I've learned from this thread is that your fucking weirdo imperial system has a unit called "acre-feet".

    Same, and I use that weirdo system every day.

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  • TraceTrace GNU Terry Pratchett; GNU Gus; GNU Carrie Fisher; GNU Adam We Registered User regular
    edited February 2017
    The amount of water that is flowing would quickly erode the ground on which the spillway is built making the hole bigger and the release of the water even more uncontrollable than it already is. The Emergency Overflow has basically the same problem, with the amount of water flowing out eroding the ground quickly enough to cause the structure to become unstable.

    I'm also going to be worried about the general stability of the dam itself because at the moment everything surrounding the dam seems to have a problem or two and generally these sorts of problems don't just spring up out of nowhere. If everything really -does- go tits up and the auxiliary spillway fails there's no telling what -that- does to the structure of the main dam itself.

    Trace on
  • GoumindongGoumindong Registered User regular
    VishNub wrote: »
    The main dam is not in danger of failing.

    Current worst case scenario is that the main spillway deteriorates to an unusable state, forcing use of the emergency overflow which is uncontrolled and untested.

    This weekend that occurred and alarming erosion of that structure was observed, suggesting that the aux spillway could fail. That structure has a height of 30ft (assuming it just vanished). More likely some cross section fails and uncontrolled releases in the millions of cfs occur. Levees downstream probably would not be able to cope with that release.

    Which is very bad, but not the nightmare of the main dam failing.

    The spillways have heights of somewhere in the range of 770 feet. They have to by mathematical necessity because they must connect the overflow point (somewhere around the top of the dam) to the outflow river (at the bottom). (Unless the outflow river flows about 740 feet up hill)

    The immediate portion of the spillway at the top is only 30 feet. But if that goes the same process that caused it to fail is now acting on the immediate portion below it; except uncontrolled and with millions of gallons of water running over it at high speed.

    To wit; the spillway doesn't just "become unusable" it becomes unusable because the hill on which it resides begins to fail from the water flow.

    wbBv3fj.png
    Trace
  • HakkekageHakkekage Space Whore Academy summa cum laudeRegistered User regular
    Trace wrote: »
    The amount of water that is flowing would quickly erode the ground on which the spillway is built making the hole bigger and the release of the water even more uncontrollable than it already is. The Emergency Overflow has basically the same problem, with the amount of water flowing out eroding the ground quickly enough to cause the structure to become unstable.

    I'm also going to be worried about the general stability of the dam itself because at the moment everything surrounding the dam seems to have a problem or two and generally these sorts of problems don't just spring up out of nowhere. If everything really -does- go tits up and the auxiliary spillway fails there's no telling what -that- does to the structure of the main dam itself.

    It's almost like upfront infrastructure maintenance spending saves money by preventing the likelihood of catastrophes like an overflowing dam wiping out a dense residential town and causing hundreds of millions in damage and lost property on top of astronomical repair costs

    Anyway I heard on NPR that environmental groups had raised concerns about the emergency spillway in 2005. I assume it is routine to ignore environmental groups, but did they actually identify the problem and in the intervening 12 years was any effort made at all to even bother checking it now out? What authority is in charge of maintaining/repairing this kind of infrastructure?

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