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The Los Angeles Aqueduct Is Wild

practical.engineering

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Re: The Los Angeles Aqueduct Is Wild

#201

Post by 01100011 »

notepad0x90 wrote: post #118

Looking at what Tehran is facing (not related to the war, water shortage), I'm wondering why california isn't investing in more desalination for SoCal, especially for LA. I see some here: https://lynceans.org/all-posts/status-of-desalination-plants... But there are only a few in SoCal and they're for smaller communities like carlsbad or santa barbara. So it is there and it is working for some, why not more? naturally…

The US needs a national water grid.

It would pay for itself after a few flooding events where were are able to redistribute the water more quickly. It also provides clean energy storage.

I've posted about it before with links to the studies but it usually just starts an argument by people worried the rest of the country is going to steal their water...

Re: The Los Angeles Aqueduct Is Wild

#202

Post by notepad0x90 »

dubyah wrote: post #187
notepad0x90 wrote: post #118

Looking at what Tehran is facing (not related to the war, water shortage), I'm wondering why california isn't investing in more desalination for SoCal, especially for LA. I see some here: https://lynceans.org/all-posts/status-of-desalination-plants... But there are only a few in SoCal and they're for smaller communities like carlsbad or santa barbara. So it is there and it is working for some, why not more? naturally…

Because the economics of desalination require locking in long term purchase/production rates at prices that dwarf current and other sources of water. SD's Poseidon desal is projected at ~$3.7k per acre ft for 2026 whereas SDCWA SWP water is ~$1.5-1.9k acre ft. Leak fixes, groundwater recharge, local aquifers, water banking, potable reuse, etc. are all more economical means of bolstering water supply. A big factor in…

that's very insightful. But if I can dive a bit deeper, why can't desalination be made at a grander scale? why aren't desalination plants trying to fill up artificial lakes for example, where those lakes are also being topped-up with reused potables. Would it help if there were much larger nuclear powerplants in the desert that take in salt water via an aqueduct from the sea and send back fresh water to artificial lakes, depositing the waste into the desert? Salton sea might be a good enough spot in socal for example, where it is already toxic and salty.

The few times I've been to the Salton area, I was amazed at the agriculture in the middle of the desert, including things like citrus plants, despite smelling the stench of salton from there. There are various lakes that dry up all the time like big bear, what would it take to keep such basins capable of sustaining fresh watter topped up with desalinated fresh water, instead of directly consuming it? In other words, making desalination an upstream element, with the goal of resisting drought overall, not just immediate fresh water supply.

I've ever wondered about places like death valley, if the elevation there is so low, is it easier to build geothermal plants that could desalinate at a greater rate there?

And since I'm asking dumb questions already, if an aqueduct to LA is possible at a 4 hour driving distance, then I know it would be costly, but is it that impractical to build an aqueduct from the great lakes, which have no shortage of fresh water, and evaporation loss could easily be recouped by the sheer volume of available fresh water supply.

Re: The Los Angeles Aqueduct Is Wild

#203

Post by clickety_clack »

01100011 wrote: post #201
notepad0x90 wrote: post #118

Looking at what Tehran is facing (not related to the war, water shortage), I'm wondering why california isn't investing in more desalination for SoCal, especially for LA. I see some here: https://lynceans.org/all-posts/status-of-desalination-plants... But there are only a few in SoCal and they're for smaller communities like carlsbad or santa barbara. So it is there and it is working for some, why not more? naturally…

The US needs a national water grid. It would pay for itself after a few flooding events where were are able to redistribute the water more quickly. It also provides clean energy storage. I've posted about it before with links to the studies but it usually just starts an argument by people worried the rest of the country is going to steal their water...

It seems like the least efficient way to solve the problem. Theres lots of water in many places in the US, if water is just allowed to be priced by how scarce it is in California, maybe people will move to a place where it’s not such a big deal.

Re: The Los Angeles Aqueduct Is Wild

#204

Post by derekdahmer »

notepad0x90 wrote: post #202
dubyah wrote: post #187

Earlier quoted context omitted.

Because the economics of desalination require locking in long term purchase/production rates at prices that dwarf current and other sources of water. SD's Poseidon desal is projected at ~$3.7k per acre ft for 2026 whereas SDCWA SWP water is ~$1.5-1.9k acre ft. Leak fixes, groundwater recharge, local aquifers, water banking, potable reuse, etc. are all more economical means of bolstering water supply. A big factor in…

that's very insightful. But if I can dive a bit deeper, why can't desalination be made at a grander scale? why aren't desalination plants trying to fill up artificial lakes for example, where those lakes are also being topped-up with reused potables. Would it help if there were much larger nuclear powerplants in the desert that take in salt water via an aqueduct from the sea and send back fresh water to artificial la…

The Owens River source for LA is so good because it’s basically a continuous gradual decline from the source to the city, requiring no pumps.

Pumping is very energy intensive. At around 2000-3000 ft the energy needed to pump fresh water starts to equal the energy needed to desalinate the same amount of salt water.

Even if it’s just going up then back down again like the Tehachapi Mountains only like 1/3rd of the energy can be reclaimed.

Re: The Los Angeles Aqueduct Is Wild

#206

Post by rayiner »

ashdksnndck wrote: post #134
paradox460 wrote: post #112

Earlier quoted context omitted.

Much easier to tell Joe homeowner he's not allowed to have a lawn than to close down the country club. Where would the rich relax then?

The country club is also negligible compared to agriculture. Farmers are politically not an attractive punching bag though.

It’s funny how the above comment reveals exactly why the problem is politically intractable.

Re: The Los Angeles Aqueduct Is Wild

#207

Post by kjkjadksj »

bronson wrote: post #145
kjkjadksj wrote: post #109

Earlier quoted context omitted.

It isn’t dried up, they maintain a certain water level in the various lakes.

The lake is completely dried up. https://en.wikipedia.org/wiki/Owens_Lake And other lakes in the area are in really bad shape.

I disagree I drive through there every winter and the lakes are very large. The ecology of the valley is dry but nowhere near as dry as say the mojave just to the south.

Re: The Los Angeles Aqueduct Is Wild

#208

Post by bronson »

kjkjadksj wrote: post #207
bronson wrote: post #145

Earlier quoted context omitted.

The lake is completely dried up. https://en.wikipedia.org/wiki/Owens_Lake And other lakes in the area are in really bad shape.

I disagree I drive through there every winter and the lakes are very large. The ecology of the valley is dry but nowhere near as dry as say the mojave just to the south.

Mojave was a desert. Owens Lake was huge. Your comparison doesn't make sense

What natural lakes in the region are still "very large"?

Re: The Los Angeles Aqueduct Is Wild

#209

Post by 01100011 »

clickety_clack wrote: post #203
01100011 wrote: post #201

Earlier quoted context omitted.

The US needs a national water grid. It would pay for itself after a few flooding events where were are able to redistribute the water more quickly. It also provides clean energy storage. I've posted about it before with links to the studies but it usually just starts an argument by people worried the rest of the country is going to steal their water...

It seems like the least efficient way to solve the problem. Theres lots of water in many places in the US, if water is just allowed to be priced by how scarce it is in California, maybe people will move to a place where it’s not such a big deal.

This is the sort of low quality reply that made me think twice about commenting. Every time I mention it it's another set of poor quality, no thought, drive by responses and downvotes.

https://www.osti.gov/biblio/963122

Why do you think it's good to let the productive agricultural land of CA lay fallow? Why do you want areas in the east to go without proper flood control? Why do you think national food security is not a priority? I could go on... Read up on it if you like, or don't. Whatever.

Re: The Los Angeles Aqueduct Is Wild

#210

Post by clickety_clack »

01100011 wrote: post #209
clickety_clack wrote: post #203

Earlier quoted context omitted.

It seems like the least efficient way to solve the problem. Theres lots of water in many places in the US, if water is just allowed to be priced by how scarce it is in California, maybe people will move to a place where it’s not such a big deal.

This is the sort of low quality reply that made me think twice about commenting. Every time I mention it it's another set of poor quality, no thought, drive by responses and downvotes. https://www.osti.gov/biblio/963122 Why do you think it's good to let the productive agricultural land of CA lay fallow? Why do you want areas in the east to go without proper flood control? Why do you think national food security is no…

I’m not a fan of people who say a comment is low quality because someone disagrees with them. I’m not going to engage any further with this discussion.
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