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The Los Angeles Aqueduct Is Wild

practical.engineering

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Re: The Los Angeles Aqueduct Is Wild

#111

Post by jimbokun »

schlauerfox wrote: post #76
strongpigeon wrote: post #16

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.

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

And when did that project start and how much has it cost and how far can you ride on what they've completed up until now?

Re: The Los Angeles Aqueduct Is Wild

#112

Post by paradox460 »

kenhwang wrote: post #93
vondur wrote: post #90

Earlier quoted context omitted.

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 wa…

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?

Re: The Los Angeles Aqueduct Is Wild

#113

Post by UltraSane »

gorfian_robot wrote: post #11

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.

Odd. Most places use water towers to provide water pressure and have backup generators for the pumps that fill them.

Re: The Los Angeles Aqueduct Is Wild

#114

Post by markdown »

ceejayoz wrote: post #62
simtel20 wrote: post #41

Earlier quoted context omitted.

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

https://www.nycfoodpolicy.org/10-facts-you-may-not-know-abou... > 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/…

Treatment is usually just the addition of chlorine and in some countries, fluoride.

Filtration isn't common.

Re: The Los Angeles Aqueduct Is Wild

#115

Post by markdown »

jmalicki wrote: post #51
mikestew wrote: post #46

Earlier quoted context omitted.

I know NYC doesn't treat their water at all… 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? 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."

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. https://newsfeed.time.com/2010/08/31/drink-up-nyc-meet-the-t...

There's no way the water is untreated. Like just about everywhere else on earth, they will add chlorine when necessary.

Re: The Los Angeles Aqueduct Is Wild

#116

Post by Melatonic »

jsLavaGoat wrote: post #107
jedberg wrote: post #45

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 (b…

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. Physician, heal thyself.

Crystal Springs isnt anywhere near Yosemite if that is what you are referencing. That being said it supposedly was gorgeous and almost as amazing before being filled with water

Re: The Los Angeles Aqueduct Is Wild

#117

Post by bombcar »

rtkwe wrote: post #92
bombcar wrote: post #87

Earlier quoted context omitted.

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…

Farm use is by far the biggest, but "taking" water from the inland empire and dragging it to LA is also a cost.

But all of this is firmly in the "we could do it if we really wanted/needed to" not "needs more energy than the sun will produce in its lifetime".

Re: The Los Angeles Aqueduct Is Wild

#118

Post by notepad0x90 »

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 i assume it's because everything costs more at the coast.

Re: The Los Angeles Aqueduct Is Wild

#119

Post by dclowd9901 »

com2kid wrote: post #28
strongpigeon wrote: post #16

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.

Seattle just got done building light rail tracks over a floating bridge. It is an insane engineering achievement. A train literally running on tracks on a road that is floating on water!

I get that it is neat but it's hardly the Hoover dam is it?

Re: The Los Angeles Aqueduct Is Wild

#120

Post by dclowd9901 »

hamdingers wrote: post #38
z3ugma wrote: post #17

"Well There's Your Problem" on the collapse of the St Francis Dam, mentioned in Grady's video https://www.youtube.com/watch?v=hxLgM1vnuUA 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

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 internationa…

In Arizona we grow alfalfa as well -- it's mind boggling to me that in places where water is so scarce we use so much of it on such a low value crop.
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