The norcal/socal divide caused by the river is funny to me. I grew up in LA, then moved to the Bay Area for college. In LA we never really talked about where our water comes from. But we were always 'in a drought' and always taught to conserve water.
My wife grew up in the Bay Area, and was told the same.
But her family is from Sacramento. Up until about 15 years ago, everyone in Sacramento paid the same for water (based on square footage of your home). There were no water meters. So they didn't conserve. They ran the sprinklers in 100 degree heat for hours, they washed sidewalks with water instead sweeping, and all the other things.
But when the meters came, her Uncle blamed SoCal for "stealing his water". He complained every month when the bill came about how he has to pay more now because of SoCal.
Owens valley, where LA "steals" water from, is on the eastern side of the Sierras.
NorCal, including Sacramento, is on the western side of the Sierras.
So unless they planned on pumping the water over/under the mountain range that surrounds it in every direction except for towards LA, that water was never available for any NorCal city to use.
The California Aqueduct delivers water from the western Sierras through the Central Valley and to Los Angeles. This is likely what NorCal refers to when they say SoCal is 'stealing our water'.
SoCal does, yes; about half the water going through the SWP from NorCal, or ~75% if you include Bakersfield/Kern as part of SoCal (though most would consider it Central Valley).
But SoCal isn't only LA. LA itself gets a bit less than half of their water from MWP, which manages the water from the SWP and the Colorado. About the same amount it gets from the the eastern Sierras. These are supposed to drop to ~10% of LA's water supply as recapture/recycling projects complete.
Or computed the other way around, LA only has rights to ~20% of the water managed by MWD. Of course water supply, distribution, and rights are all blended and traded around all the time, but generally speaking it's not "LA" using up that water from NorCal, the consumption is significantly more from the cities and farms that came after.
tl;dr: Urban water use is tiny. In NorCal, the vast majority of the water flows unimpeded to the sea. In the Central Valley, most water is used for agriculture. Agricultural water use in any one of the 3 major basins in the Central Valley is more than all urban areas in California combined. Unsurprisingly, urban use is the primary one in the SF and LA areas, but the absolute totals are very small compared to total CA water supplies.
Owens valley is basically dried up from the water that LA takes. It's interesting as you drive in the towns in the Valley and you see all the LA Department of Water and Power offices over 200 miles from Los Angeles. The courts had to force the LA DWP to quit taking too much water from the streams that feed Mono Lake as it was in danger of drying out.
Yep, Owens valley is basically an environmental disaster created by LA. So in the grand scheme of things, buying water from NorCal is better than stealing from the Owens valley through antiquated water rights.
But really, California (and really the entire Western US) needs a water rights governance overhaul. Right now the focus is all on urban water use, which is practically negligible compared to the agricultural water rights usage.
they are saying that LA takes water from sources which would otherwise drain into the sacramento and san joaquin river delta. The video from this post mentions the California State Water Project which takes water from the Feather River (Oroville Dam) and distributes it along the Western edge of the central valley South to Bakersfield where it is then pumped over the mountains both towards Los Angeles and further East to San Bernardino and Riverside. It provides way more water to SoCal than the two Los Angeles-specific aqueducts from the Owens Valley on the Eastern side of the Sierras.
Yes, Norcal spent decades wagging fingers at SoCal about this. There were books like Cadillac Desert.
Meanwhile, San Francisco drinks clean glacier water that a valley in Yosemite was destroyed to provide this and they refuse to repurpose a downstream damn that has enough capacity to do it.
Being from LA, I am used to a water system that works without needing power. I think most of CA is like that. It was a surprise to lose the water back east when the power went out during a storm.
The only places I've heard of losing water during power outages are houses that use a private well (no power, no well pump), which would be the case anywhere. Municipal water systems may or may not use power to provide pressure, but are going to have generator power outside of the most severe outages.
I wonder if this was in an apartment building. We owned a condo in a 5 story (4+1) apartment building and because it was taller than the San Jose water system was built for, our building needed (electric) pumps to provide water pressure to the building (there were tanks on the roof). If we lost power, then we lost water.
Now that we have moved to a 2 floor detached home (also in San Jose) we do not have that issue, and everything is gravity fed.
Usually these relatively low height kinds of top-tank systems lose water for the entire apartment building, because there's one pump to raise the water to the tank, which then passively provides the pressure (usually through pressure regulators at each floor if I remember right).
Larger buildings tend to have multiple independent systems
We happened to live on the top floor, so I don't have personal experience for the lower floors, but the communication on the (non official) group chat for the building always hinted that any water outages (we had a few non-power issues with the pumps as well) applied to to the whole building. But thinking back that could be an unfounded assumption.
I know NYC doesn't treat their water at all, but LA doesn't either?
My city runs on surface water, so we have treatment and then pump to storage tanks. You would have to be out for quite a while to run the city out of water, though - the tanks are large.
LA definitely treats the water. Both the surface water before consumption (I'd be surprised if any city doesn't do this) and the wastewater, for reclamation for nonportable use like irrigation, and for recycling back into the general clean water supply.
The aqueduct water is specifically purified by the Los Angeles Aqueduct Filtration Plant. That plant is gravity fed, but it doesn't operate without power.
LA just has the advantage of having mountains in the city, so it's cheaper building more elevated water storage so the capacity lasts longer during power interruptions (which are also not as common or extended as they are in the east). They will still eventually run out if they're not replenished by powered pumps.
Where did you get that idea about NYC water being untreated? NYC treats its water. Chlorine is added if and when needed. Testing stations exist to evaluate water quality all around the boroughs, etc.
You can't have a city of millions of people and have the water be potable from the tap without testing and treatment
> New York City’s water (including drinking water) is unfiltered, making it the largest unfiltered water system in the country. Were New York to begin filtering its water, it would cost the city approximately 1 million dollars per day to operate the filtration plant.
They have hundreds of sampling stations to check daily.
He was talking about the drinking water that comes from the faucet, not the sewage.
The untreated NYC water has tiny crustaceans in it, which make it not Kosher, which is why thee bagels from a Jewish deli in NYC are so good. Go figure.
Sometimes it feels like the US has lost its appetite for grand structural projects like that. Maybe it’s just that I’m unaware of them and that impression is the result of survival bias, but given how impossibly hard it is to just build anything where I live (Seattle), I’m not so sure.
Fair. Maybe I'm too much if the weeds of this because all I can think of is how much of a fight it was to pass ST2 and ST3 and how we haven't even started on the Ballard line despite voting for it in 2016 (10 years ago!) and how it might be delayed forever.
No, it's not an insane engineering achievement. It's just a normal one, because nobody else has floating bridges, nobody else needed it. It's also years late and costs 10x more than it should.
It's also the wrong stupid technology. The trains are constrained on space because of the low-floor bullshit. It's the longest light rail in the country, it's too fucking long and slow. Even if we fully built out ST3 it can't handle more than ~20% of commuters. It can't be expanded with express tracks because it's built deep underground, so the commute is so much slower than the equivalent in other countries and will NEVER compete with the automobile except during peak rush hour. The northern stations are next to the freeway so over half the land that could be transit-oriented development can't be, and then what's left is devoted to parking anyway. Complete, total waste of a once-in-a-lifetime opportunity, built and planned by people who don't and won't ever use transit.
That 10x cost directly makes it so we can't build out our system properly and we keep building out car infrastructure because people would rather have a car and save 2 hours a day commuting.
> No, it's not an insane engineering achievement. It's just a normal one, because nobody else has floating bridges, nobody else needed it. It's also years late and costs 10x more than it should.
Your other points aside -
Doing something no one else has ever done is the definition of an engineering achievement.
There isn't a set of best practices. There aren't a bunch of off the shelf parts, there aren't any contractors who can help you out because they've done it a dozen times before. It is an original engineering challenge.
Pulling it off is by definition an achievement.
That said, 100% agree about the station placement. Heck the stations that are well placed were poorly designed, they should be profitable by including commercial real estate and residences, with the revenue from both going to Sound Transit to pay for the system.
But no, we didn't do that and I can't even get a cup of coffee, in Seattle, at our light rail stations.
I don't think you're wrong. Every time someone says we can't do high speed rail it makes me very sad. And as far as Seattle goes... my commute is substantially affected by the I-5 closures. It's somewhat shocking to me that we allow infrastructure to decay as much as we do.
I'd be happy about the light rail expansion if they weren't talking about delaying the Ballard line indefinitely. :(
The commute is slow because the light rail is slow. It's the wrong technology for commuter rail and there are too many stops. (I'm assuming you live north).
Can't do highspeed rail because it's too impractical and expensive, while we're spending a west coast highspeed rail network worth of money on the least popular war in US history.
California is spending the money and what they're building is useless (oh big passenger demand from Merced to Bakersfield, fuck right off with that) and costs 10x what China, France, Japan, etc pay.
We're literally right now building a huge high speed rail project that is planned to link san diego to san francisco through LA, bakersfield and fresno. Progress is made on it daily. https://www.youtube.com/CAHighSpeedRail
If you watch the OP, you'll see that the construction of this aqueduct caused billions of dollars worth of environmental devastation. Rail all you want against regulations, but when an argument boils down to "I wish we didn't have to internalize all these costs and could just push them off on someone else", I'm not especially sympathetic.
LA has paid billions to remediate, but the actual cost is incalculable. Not sure who is "railing against regulations" but there are obviously downsides to heavy environmental regulations. Debatable if CA is striking the right balance.
Certainly that’s part of it, but also just NIMBYism. Los Angeles were able to defeat the Owen’s Valley farmers back then, I don’t think they would be now.
It’s too complicated to corruptly make money off of a large project like that. It’s much easier to just buy a bunch of drugs and needles and give it to the methheads, or spend money on homeless while building zero homes.
There's a poem carved into the stonework of Washington Union Station, part of the art installation The Progress of Railroading from c. 1909:
the old mechanic arts / controlling new forces / build new highways / for goods and men / override the ocean / and make the very ether / carry human thought
the desert shall rejoice / and blossom as the rose
There is no water scarcity in California, only misallocation. The vast majority of our water is heavily subsidized and used for agriculture, and a substantial amount of those crops are grown for export, yet agricultural exports makes up an insignificant part of California's economy.
We could end all California water scarcity talk today, with no impact to food availability for Americans, by curtailing the international export of just two California crops: almonds and alfalfa.
Anecdotally, my friend's grandma was an almond farmer. As they drove past a river in the Central Valley, she exclaimed "Why is there water in that river?! Those could be watering my almond trees!"
So why hasn’t that been done? Have some representatives and senators set limits on almond exports. Surely they wouldn’t be voted out in the next election given how farmers are outnumbered.
Almonds are climate-appropriate product and valuable. Alfalfa can cheaply be grown off rainwater in the Midwest and it alone frees up sufficient water.
The problem is alfalfa is expensive to transport (heavy due to desired moisture content). So while it can be cheaply grown in the Midwest, it can't be cheaply transported from the Midwest to where buyers of alfalfa are (typically overseas).
Alfalfa is also a staple for crop rotation, so any farming operation will still grow some alfalfa to maintain rotation for good soil health (or during bad condition seasons since it's hardier to poor conditions and not a permanent crop).
If alfalfa cannot be exported (through policy or economic conditions), the low price attracts more livestock production in-state (which would be even worse for water use).
Those things makes it a hard crop to target for sustainability and export.
I was surprised to find out it was largely uncovered, though I guess it probably makes it much cheaper to construct. I usually think of aqueducts as pipes or tunnels, like Persian qanāts. I wonder how much water is lost due to evaporation.
There's some testing to see how covering open irrigation canals with solar panels which would reduce evaporation and generate power
> Their analysis found that putting solar panels over the 4,000 miles of California’s open canals could save up to 63 billion gallons of water annually
> could save up to 63 billion gallons of water annually
To put it into perspective, 63 billion gallons is 193340 acre-feet, which is 0.5% of california's water use (a bit under 40 millions acre-feet). That's a tenth the water consumption of lawns, which is 1/15th the water consumption of agriculture.
Thanks! I forgot that article, but now I remember that I read or skimmed it when it made the rounds last year. It's actually where I first learned that the aqueducts were uncovered!
Correct it's massively energy intensive to filter the salt out the newest best ideas still use ~2 KWh/m3 of water and that's a lab system in perdue that batches the process instead of having it run continuously which is why current RO desalination systems require so much energy.
Which to scale back up and complete the comparison to the state of the art in lab "batch reverse osmosis" systems I was originally talking about that's ~12.7 kWh/m3.
California pays other states to take its excess solar energy. Power for a project like this isn't the issue, actually building the system is the issue.
They wouldn't if you switched just Urban water use from natural sources to desalination. To do that you need to replace the ~5 million acre feet of water, ~6,167,400,000 m3, that goes into the Urban bucket which is all of the water used to keep people alive, clean, and all industrial uses of water. [0] That comes to ~ 12BkWh of energy needed to scale up batched reverse osmosis to take over just the life and job required water needs which is about 25% of the total solar power generated in all of 2025 via grid-scale solar farms. CA does export some during the day due to excess solar but is still a net importer of power.
Those are the numbers I was looking for - that means that (ignoring build-out costs) total desalination for CA would be on the order of 10% of the 3 gorges dam yearly output (max).
Using a system that's currently in a lab scale only and ignoring other energy costs like moving the water to the plant, mixing the briny output back down to acceptable levels, and then pressurizing the system to replace the gravity fed design it currently uses.
For a rough estimate for replacing agricultural uses too ~6x that urban figure at least then weep at the amount of pumps you'd need to bring that water up and inland to the farm lands from the coast. At least for replacing urban use most of the population lives on/near the coast where the water would be produced.
For usage where the water mostly returns as sewage, is treated and then returned to the ocean, you can just dilute the brine with the treated discharge and then it returns at basically the original salinity.
Growing up in LA, I was fascinated as a kid watching the water flow down this aqueduct. Anytime we drove by it on the way to Magic Mountain, I'd hope that it would be a water-on day.
Came here to post this. Dam good book on the shifty maneuvering that resulted in the Owens Valley Diversion and ultimately the population center that is LA.
My wife grew up in the Bay Area, and was told the same.
But her family is from Sacramento. Up until about 15 years ago, everyone in Sacramento paid the same for water (based on square footage of your home). There were no water meters. So they didn't conserve. They ran the sprinklers in 100 degree heat for hours, they washed sidewalks with water instead sweeping, and all the other things.
But when the meters came, her Uncle blamed SoCal for "stealing his water". He complained every month when the bill came about how he has to pay more now because of SoCal.
NorCal, including Sacramento, is on the western side of the Sierras.
So unless they planned on pumping the water over/under the mountain range that surrounds it in every direction except for towards LA, that water was never available for any NorCal city to use.
https://en.wikipedia.org/wiki/California_Aqueduct
Would be interesting to see the relative amounts of use by LA and by agriculture in the Central Valley though.
But SoCal isn't only LA. LA itself gets a bit less than half of their water from MWP, which manages the water from the SWP and the Colorado. About the same amount it gets from the the eastern Sierras. These are supposed to drop to ~10% of LA's water supply as recapture/recycling projects complete.
Or computed the other way around, LA only has rights to ~20% of the water managed by MWD. Of course water supply, distribution, and rights are all blended and traded around all the time, but generally speaking it's not "LA" using up that water from NorCal, the consumption is significantly more from the cities and farms that came after.
https://www.ppic.org/publication/water-use-in-california/
tl;dr: Urban water use is tiny. In NorCal, the vast majority of the water flows unimpeded to the sea. In the Central Valley, most water is used for agriculture. Agricultural water use in any one of the 3 major basins in the Central Valley is more than all urban areas in California combined. Unsurprisingly, urban use is the primary one in the SF and LA areas, but the absolute totals are very small compared to total CA water supplies.
But really, California (and really the entire Western US) needs a water rights governance overhaul. Right now the focus is all on urban water use, which is practically negligible compared to the agricultural water rights usage.
Meanwhile, San Francisco drinks clean glacier water that a valley in Yosemite was destroyed to provide this and they refuse to repurpose a downstream damn that has enough capacity to do it.
Physician, heal thyself.
Now that we have moved to a 2 floor detached home (also in San Jose) we do not have that issue, and everything is gravity fed.
Larger buildings tend to have multiple independent systems
My city runs on surface water, so we have treatment and then pump to storage tanks. You would have to be out for quite a while to run the city out of water, though - the tanks are large.
The aqueduct water is specifically purified by the Los Angeles Aqueduct Filtration Plant. That plant is gravity fed, but it doesn't operate without power.
LA just has the advantage of having mountains in the city, so it's cheaper building more elevated water storage so the capacity lasts longer during power interruptions (which are also not as common or extended as they are in the east). They will still eventually run out if they're not replenished by powered pumps.
You can't have a city of millions of people and have the water be potable from the tap without testing and treatment
> New York City’s water (including drinking water) is unfiltered, making it the largest unfiltered water system in the country. Were New York to begin filtering its water, it would cost the city approximately 1 million dollars per day to operate the filtration plant.
They have hundreds of sampling stations to check daily.
https://www.nytimes.com/2025/05/01/nyregion/nyc-tap-water-qu...
This causes some issues for observant Jews, because the water technically might not be kosher.
https://oukosher.org/blog/consumer-news/nyc-water/
https://www.nytimes.com/2004/11/07/nyregion/the-waters-fine-...
EDIT: I'm a dork an grabbed the wrong URL. Changed URL to a PDF for lack of better.
A major metro doesn’t treat its tap water? Where on earth did you get that crazy idea?
<old URL deleted>
https://www.nyc.gov/assets/dep/downloads/pdf/water/drinking-...
I'll save some digging: "Even without filtration, the water is carefully treated to reduce the risk of harmful microorganisms."
The untreated NYC water has tiny crustaceans in it, which make it not Kosher, which is why thee bagels from a Jewish deli in NYC are so good. Go figure.
https://newsfeed.time.com/2010/08/31/drink-up-nyc-meet-the-t...
Tap water is treated (UV and chloride disinfecting), but is largely not filtered: https://en.wikipedia.org/wiki/New_York_City_water_supply_sys...
https://images.nebula.tv/5ba7e541-f57c-44cc-a91d-6a89bad158d...
It is an insane engineering achievement. A train literally running on tracks on a road that is floating on water!
It's also the wrong stupid technology. The trains are constrained on space because of the low-floor bullshit. It's the longest light rail in the country, it's too fucking long and slow. Even if we fully built out ST3 it can't handle more than ~20% of commuters. It can't be expanded with express tracks because it's built deep underground, so the commute is so much slower than the equivalent in other countries and will NEVER compete with the automobile except during peak rush hour. The northern stations are next to the freeway so over half the land that could be transit-oriented development can't be, and then what's left is devoted to parking anyway. Complete, total waste of a once-in-a-lifetime opportunity, built and planned by people who don't and won't ever use transit.
That 10x cost directly makes it so we can't build out our system properly and we keep building out car infrastructure because people would rather have a car and save 2 hours a day commuting.
Your other points aside -
Doing something no one else has ever done is the definition of an engineering achievement.
There isn't a set of best practices. There aren't a bunch of off the shelf parts, there aren't any contractors who can help you out because they've done it a dozen times before. It is an original engineering challenge.
Pulling it off is by definition an achievement.
That said, 100% agree about the station placement. Heck the stations that are well placed were poorly designed, they should be profitable by including commercial real estate and residences, with the revenue from both going to Sound Transit to pay for the system.
But no, we didn't do that and I can't even get a cup of coffee, in Seattle, at our light rail stations.
I'd be happy about the light rail expansion if they weren't talking about delaying the Ballard line indefinitely. :(
(more details: https://news.ycombinator.com/item?id=47457884)
the old mechanic arts / controlling new forces / build new highways / for goods and men / override the ocean / and make the very ether / carry human thought
the desert shall rejoice / and blossom as the rose
Or, rewritten for the Los Angeles Aqueduct:
the desert shall wither / and blossom in a plume of dust [1]
[1] https://www.latimes.com/environment/story/2025-06-19/owens-v...
Also I love when they refer to it as the "_First_ California Water Wars" in a grim realization of the future of water scarcity in the West
We could end all California water scarcity talk today, with no impact to food availability for Americans, by curtailing the international export of just two California crops: almonds and alfalfa.
Alfalfa is also a staple for crop rotation, so any farming operation will still grow some alfalfa to maintain rotation for good soil health (or during bad condition seasons since it's hardier to poor conditions and not a permanent crop).
If alfalfa cannot be exported (through policy or economic conditions), the low price attracts more livestock production in-state (which would be even worse for water use).
Those things makes it a hard crop to target for sustainability and export.
> Their analysis found that putting solar panels over the 4,000 miles of California’s open canals could save up to 63 billion gallons of water annually
https://www.universityofcalifornia.edu/news/solar-panel-cove...
To put it into perspective, 63 billion gallons is 193340 acre-feet, which is 0.5% of california's water use (a bit under 40 millions acre-feet). That's a tenth the water consumption of lawns, which is 1/15th the water consumption of agriculture.
Most of the video content has the correct coloring, from my experience observing the aqueduct.
Desalination is dominated by operating costs.
The most efficient commercial desalinator for boats is 32 Watts a gallon.
[0] p2 of https://cwc.ca.gov/-/media/CWC-Website/Files/Documents/2019/...
For a rough estimate for replacing agricultural uses too ~6x that urban figure at least then weep at the amount of pumps you'd need to bring that water up and inland to the farm lands from the coast. At least for replacing urban use most of the population lives on/near the coast where the water would be produced.
Intermittently. Essential services like water (with expensive fixed costs) aren’t a good fit for absorbing variable supply.
> Power for a project like this isn't the issue
California has the country’s most expensive power [1] in part due to policymakers constantly assuming it’s free.
[1] https://www.electricchoice.com/electricity-prices-by-state/
Something along the lines of "we fought tooth and nail to save LA from development"?
https://www.imdb.com/title/tt0071315/?ref_=nv_sr_srsg_0_tt_8...
(Chinatown)