Lake Mead at "inactive pool" - Hoover Dam and climate change

[Broomstick]

Hoover Dam Hydroelectric is off-line

The video rambles quite a bit, so feel free to skip ahead if you want to. 18:09 is where they get to the big damn and take a look at the turbine intakes. If you don't feel like watching a video skip down to the text below it.

https://youtu.be/gND12rp0IDM

Measurements are given in Imperial because that's what's used over here. To some extent the exact units used don't matter, but if you must, remember dividing feet by three gives you a rough number in meters.

The lake water level is measured in feet above sea level (MSL). 1050 MSL is the lowest point of the turbine intakes. As of yesterday, the lake is down to 1046 MSL, or roughly a meter below the lowest intake. Water no longer flows to the turbines, which presumably no longer turn and thus Hoover Dam, once the world's largest hydroelectric power plant, no longer generates power.

I can't for the life of me understand why this is NOT in the news.

Of course, the lights didn't instantly go out in Las Vegas because Hoover isn't the only power plant but, holy crap, it's 1/3 of the electricity going to Vegas and 10% of what goes to Los Angeles, maybe more. And every other hydro plant in the west is facing the exact same problem: dropping water levels. This is climate change. This is real. This is happening now.

In addition - the reservoir is a V shape as it is a river canyon. When full, it contains a massive, massive amount of water. As you go deeper, because the width narrows, there is a small mass of water for each unit of measure. The deeper you go, the faster the water goes down. Not sure I'm explaining this well, but the upshot is that the water level drops faster the deeper into the valley you go. Meaning dropping water levels are accelerating.

After "inactive pool" - the level at which the dam can no longer generate electricity, 1050 feet above sea level - the next stop is "dead pool". That's 895 MSL. At that point water no longer goes past the damn at all. Lake Mead becomes a stagnant pool of water (one that may continue to evaporate). At that point the Colorado River stops flowing. The river below Hoover dries up. Completely. Sure, it's not instant, it will take a little time for the remnant moisture to evaporate, but that's where we would be.

There are two and only two ways to "fix" that. One, you somehow get more water into Lake Mead, raising the water level above dead pool. Well, if we had a firm handle on that perhaps the we wouldn't now be at inactive pool. Two, blow the dam. Which, literally, means blast/drill/whatever a hole into the dam. Which, of course, doesn't do the dam structure much good.

I am not predicting where we go from here, or how long it would take. Suffice to say, though, that losing the Colorado River would have dire consequences.

On a related note, here is a short (4:23 minutes) video about what the government is trying to do about water supply on the Colorado.

https://youtu.be/3kvVmXdnSb4

[bilateralrope]

Putting hole into the dam seems like a temporary solution at best. If the water level is going down, it's going to keep going down until it's below the level of the hole or some other upstream obstruction. Assuming the dead pool level is currently above the bottom of the reservoir, which is something I don't know.

[Broomstick]

The deepest point of the reservoir is about 200 feet (60 or so meters) below the dead pool level, but keeping in mind that the floor of Lake Mead is a natural river valley and not a smooth, uniform, man made structure that floor is probably pretty rough, probably silted up in some spots, the lowest outflow is probably based on being high enough to not get clogged with sludge and debris on a regular basis.

You're correct, poking a hole in the base of the dam would, at best, be a temporary solution. The problem is that there is less water. Period.

[LadyTevar]

Holy....

I'm guessing they're not talking about it to not panic people.

Now, it's 1/3 of the power to Vegas, but what of the smaller towns nearby?

[muse]

Many millions of people living in the desert, plus extensive farming of rice, almonds, and other water intensive crops.
What could possibly go wrong?

[EnterpriseSovereign]

I'd been aware of the water level dropping for some years now and knew at some point it would drop below the level of the intakes at the dam, I'd have thought they'd have gotten a handle on things before that could happen. My understanding was that it's not actually Las Vegas consumption that's responsible for the dropping water levels but steadily increasing demand from all the other towns and villages that draw water from Lake Mead as they grow. An article from this time last year: Lake Mead: The devastating impact of a 22-year drought on America's largest reservoir as water levels fall to record low.

Nature has a way of telling its story in a more powerful way than any words.

The watermark around Lake Mead is a graphic illustration of just how much has changed in America’s largest reservoir.

Huge white bands, as high as 10 double decker buses, mark its craggy sides.

The 50-metre ring line shows where the water level was and how far it has fallen.

The reservoir is at just 35% capacity, the historic Hoover Dam it powers is producing 25% less output, and scorching summer temperatures are nudging the mercury to record levels.

But don’t call this a crisis to those managing water and power in Nevada.

It’s a concern, yes, but apparently not a catastrophe in the making. Talk of Hoover Dam being rendered obsolete within eight years is dismissed as folly.

The historic Hoover Dam it powers is producing 25% less output.
However, things are changing in America’s West as a two decade mega-drought and environmental change are compounded by temperatures which are extreme even for this part of the world.

It was 43 Celsius (111 Fahrenheit) in Las Vegas at the weekend.

As a result the authorities are on the verge of declaring a historic water shortage in the Colorado Basin.

That means the water supply will be reduced in Nevada, California and Arizona. Because Arizona has more farmland it is likely to take a cut of up to 18%.

Twenty five million people rely on Lake Mead for water, eight million take power from the Hoover Dam.

Strikingly, the drain is not so much from the excess of Las Vegas’ strip which conserves and recycles most of the water it needs, but agriculture and the local community.

The pressure is now on farmers to find different ways to irrigate and residents to be water-wise.

While the local and federal government manage the big picture, locals are being urged to do their bit.

Twenty five million people rely on Lake Mead for water.
Across Las Vegas, day and night, water waste investigators are busy at work.

Their job is to find those flouting water laws, to educate them, and if that fails, to force change through fines.

It might sound like a small part of a big problem, but in a few hours on the road with them you realise how much water is wasted.

Whether it’s a sprinkler spewing water across the street or a broken faucet pumping water down the drain, it’s all water that is disappearing from a system under strain.

Their motto is every drop counts and it’s increasingly clear it does - especially when those drops run into millions of gallons.

Every system has its breaking point but those managing this one believe they have appropriate checks and balances in place to protect those who rely on it despite the environment serving a curve ball that came faster than they expected.

The reality is everyone is going to have to do more with less - whether on the Strip, in the water hungry fields or in homes across the region.

The message is very clear, everyone’s world needs everyone’s help and the responsibility is not someone else’s.

As an aside:
Lake Mead: More human remains found days after body in barrel discovered.

More human remains have been discovered in Lake Mead less than a week after a barrel containing a body was found in the drought-struck Nevada reservoir.

Human skeletal remains were uncovered at Callville Bay on Saturday May 7 at around 2pm, according to the National Park Service.

Park rangers set up a perimeter around the scene and recovered the remains, while the Clark County Medical Examiner was contacted to determine the cause of death.

The investigation is ongoing.

It follows the launch of a murder investigation after a body was discovered in a barrel on Sunday May 1.

It is believed the victim died from a gunshot wound and was likely killed between the mid-1970s and early 1980s based on the shoes the victim was wearing, Las Vegas Metropolitan Police Department (LVMPD) said in a statement.

Police are reportedly not going to “rule out” the possibility the killing may have been Mafia-related given mob-connected casinos ruled the Las Vegas Strip in the 80s.

The barrel was discovered as an ongoing drought caused the USA’s largest reservoir’s water level to drop.

According to the Southern Nevada Water Authority, the water level of Lake Mead dropped by nearly 150 feet since 2000 due to “drought and climate change”.

“It’s really odd in the sense that had the lake never receded, we would never have discovered the body,” Lt. Ray Spencer told the New York Times.
The victim’s identity will be released by the Clark County Coroner’s Office once it becomes available.

[Broomstick]

Found this site that gives the water level of Lake Mead.

Wednesday it was down to 1046 feet above sea level

Thursday evening it was 1043. That's three feet. One meter. In one day.

The 26th largest lake in the US dropped 1 meter in 1 day. Think about that.

Did, finally, see a sound bite on the morning TV news about it. Mentioned the low levels and that the lake/dam were in danger of "dead pool" but nothing about the power generation. Did have reassurances about drinking water still being supplied (which it is, and that's a good thing).

We're about 50 meters (give or take) from dead pool. The math is... simple, but alarming.

If it does hit dead pool late summer/fall that doesn't mean it will stay there - there's the option of increasing the flow from dams upstream (although that has side effects) and there will be additional input from melting snow next spring, but it's an understatement to say the situation is not good.

[Zaune]

This would probably be a good time for a temporary ban on lawn sprinklers. Think the Republicans would go for it, or would that be socialism?

[Broomstick]

The wealthy and privileged will prioritize their lawn sprinklers over growing food - which is insane, but human.

There are reports of blackouts and rolling blackouts in the Southwest. Sure, that happens during heat waves (and one is currently in progress) but I can't help but think that diminished hydro capacity is part of that, too.

[Tribble]

This would probably be a good time for a temporary ban on lawn sprinklers. Think the Republicans would go for it, or would that be socialism?

Republicans will keep using their lawn sprinklers as much as they damn please… while blaming Biden, his Godless Socialism, the Great Replacement and LGBT for the shortage.

[Esquire]

I'm curious; what percentage of the relevant area's water use do you think lawn sprinklers account for?

[Jub]

It makes far more sense to kill water to the vegas water shows, water-intensive cash crops, and other purely capitalist wastes of a precious resource even if lawns, personal swimming pools, etc. are also wasteful.

[J]

It makes far more sense to kill water to the vegas water shows, water-intensive cash crops, and other purely capitalist wastes of a precious resource even if lawns, personal swimming pools, etc. are also wasteful.

You might want to think that one through to really understand what you're asking for...

[NecronLord]

You might want to think that one through to really understand what you're asking for...

Someone thinks farmers and their labourers growing cash crops are doing it for a hobby and are 'independently wealthy.'

[Jub]

It makes far more sense to kill water to the vegas water shows, water-intensive cash crops, and other purely capitalist wastes of a precious resource even if lawns, personal swimming pools, etc. are also wasteful.

You might want to think that one through to really understand what you're asking for...

You might want to think that one through to really understand what you're asking for...

Someone thinks farmers and their labourers growing cash crops are doing it for a hobby and are 'independently wealthy.'

I understand that precisely.

Fuck growing water-hungry cash crops in a water-starved region. Nobody should be growing almonds, rice, or soy in a dessert unless they're able to supply their own water.

Subsidize the farmers and support a shift to crops that don't guzzle down water that no longer exists.

[madd0c0t0r2]

You might want to think that one through to really understand what you're asking for...

Someone thinks farmers and their labourers growing cash crops are doing it for a hobby and are 'independently wealthy.'

It might be cheaper to just buy a farmer's annual crop now on the condition they turn the sprinklers off, then try to do some sort of emergency pumping and water redistribution. Especially if the farmer isn't sure they will actually have anything to harvest if supplies completely run out. Almond growers won't have that felxibility, but annuals like rice, maize or cotton will.


But is there no concept of a hosepipe ban or a staged drought cutback process there? They are common and well understood in the UK.

[Zaune]

I'm curious; what percentage of the relevant area's water use do you think lawn sprinklers account for?

Probably not that high compared to agricultural irrigation etc, but they're definitely a completely unnecessary use of the public water supply. Growing certain crops might be an unsustainably water-intensive way to make a living in the surrounding area but at least that serves some sort of practical purpose in a way that watering a lawn does not.

And I would also endorse a temporary ban on refilling artificial ponds, fountains etc as well as private swimming pools until water levels improved. Those tend not to come up as much when the water companies impose emergency restrictions on hosepipes and sprinklers in my country.

[NecronLord]

I understand that precisely.

Fuck growing water-hungry cash crops in a water-starved region. Nobody should be growing almonds, rice, or soy in a dessert unless they're able to supply their own water.

Subsidize the farmers and support a shift to crops that don't guzzle down water that no longer exists.

I suspect that will take time, particularly if you're *not* just willing to pay them to have fields stand empty, compared to saying 'no private swimming pools' though.

[Jub]

I understand that precisely.

Fuck growing water-hungry cash crops in a water-starved region. Nobody should be growing almonds, rice, or soy in a dessert unless they're able to supply their own water.

Subsidize the farmers and support a shift to crops that don't guzzle down water that no longer exists.

I suspect that will take time, particularly if you're *not* just willing to pay them to have fields stand empty, compared to saying 'no private swimming pools' though.

At this point, you have to pay them to let fields stand fallow. The current use of water in the US South West is unsustainable and the crops are a large part of the problem.

[EnterpriseSovereign]

Besides, H2O in the water shows is re-used anyway, it's not like they pour it down the drains. If anything, it's the energy expenditure needed to run them that you should be worried about.

[Jub]

Besides, H2O in the water shows is re-used anyway, it's not like they pour it down the drains. If anything, it's the energy expenditure needed to run them that you should be worried about.

The Bellagio apparently runs from a private well which is good because it burns 12 million gallons of water yearly.

[Ralin]

I vaguely remember reading that water parks/shows in places like Vegas use some sort of workaround to recycle the water they use that makes it surprisingly efficient and a lot less wasteful than you'd think.

[Esquire]

I'm curious; what percentage of the relevant area's water use do you think lawn sprinklers account for?

Probably not that high compared to agricultural irrigation etc, but they're definitely a completely unnecessary use of the public water supply. Growing certain crops might be an unsustainably water-intensive way to make a living in the surrounding area but at least that serves some sort of practical purpose in a way that watering a lawn does not.

And I would also endorse a temporary ban on refilling artificial ponds, fountains etc as well as private swimming pools until water levels improved. Those tend not to come up as much when the water companies impose emergency restrictions on hosepipes and sprinklers in my country.

Just to humor me, would you mind taking a stab at a numerical estimate? We can roll up all outdoor residential use if you like, that's probably easier to get data on.

[Jub]

I found this article from last year:

https://www.nevadacurrent.com/2021/07/1 ... -pandemic/

Some relevant quotes are:

"Looking at water billing and usage from the Henderson Water District covering all users, the study identified a number of trends and shifts in habits around water usage, including that the average Southern Nevada household used up to 3% more water monthly during the COVID stay at home orders. This led to an extra 491 million gallons of water used a month during the first five months of the lockdown compared to pre-pandemic levels. "

"Commercial usage in contrast decreased by up to 36% while schools fell by up to 66%. However, those decreases were not enough to make up for the increase in residential water use, leading to a net increase in overall water usage. Residential users comprise 98% of the water district’s user base, according to the study."

This is for Southern Nevada and doesn't really delve into indoor and outdoor residential water usage but it does show one factor in the current situation. If that 3% number is accurate, then during the pandemic residential use in Southern Nevada used 196 billion gallons of water. Meanwhile, Almonds alone used 6.9 trillion gallons of water.

If the extra 5.9 billion gallons of water used during the pandemic is an issue, how is greater than 1000 times more water used on almonds not a larger issue?

[Zaune]

Just to humor me, would you mind taking a stab at a numerical estimate? We can roll up all outdoor residential use if you like, that's probably easier to get data on.

I think Jub did a better job of this than I could have.