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Big water cutbacks ordered amid Colorado River shortage

latimes.com

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Re: Big water cutbacks ordered amid Colorado River shortage

#21

Post by Syonyk »

no_wizard wrote: post #3

Could we feasibly just run desalination stations from the coasts and pipe the water - like oil - to fill up these reservoirs? Setting cost aside for a second, is there any reason not to do something like this?

I mean, if you don't care in the slightest about cost of the plants, the energy required, the land needed to run the giant tunnels... maybe? It's probably technically possible within the constraints of "I have a full country's resources available and can demand they be used to satisfy my absurd requirements and won't face huge blowback for using resources this way."

But you can pencil it out. Cuts next year are 2-4 million acre feet of water. What would it take to bring that in?

An acre foot is 325,851 gallons, give or take. So, four of those is ~1.3e12 gallons of water for a year. A year has 31,536,000 seconds, so you're looking at a mere 41,000 gallons per second, or about 6500 cu*ft/s. Which is a good sized river's flow.

It's also 155 m^3 of water per second, or about 3.5 billion gallons a day.

I'm seeing [0] a plant in San Diego running 50M gallons a day on 35MW, so you'd need ~70 of those plants (or about 2.5GW) to manage your water supply. California's purring away at 33GW right now, so the energy required, while massive, is feasible.

Trying to figure out how to move 40k gallons a second a distance of 1000 miles exceeds my physics skills, but you could probably figure it out with the right calculators or CFD handwaves. But it's not going to be cheap.

Seems... somewhat easier to reduce demand, though.

[0]: https://www.energy.gov/sites/default/files/2019/09/f66/73355...

Re: Big water cutbacks ordered amid Colorado River shortage

#22

Post by MengerSponge »

no_wizard wrote: post #3

Could we feasibly just run desalination stations from the coasts and pipe the water - like oil - to fill up these reservoirs? Setting cost aside for a second, is there any reason not to do something like this?

It would require a tremendous amount of energy. Lake Powell is more than 1km above sea level, which means each liter of water would require 10kJ just in gravitational potential energy.

The reclamation effort is 1 maf (million acre-feet) of water over a year, which if supplied continuously from sea level with perfectly efficient pumping and transport corresponds to ~10 GW of power. A typical nuclear power plant generates 1GW, so without any transport losses, you'd need 10 new plants running full-time just to move the water up the hill.

Add in the desalination challenges and transport losses, and you're talking what, 20-40 new nuke plants?

Re: Big water cutbacks ordered amid Colorado River shortage

#23

Post by [deleted] »

pm90 wrote: post #20
ar813 wrote: post #10

The answer to this problem lies here: “Entsminger pointed out that roughly 80% of the river’s flow is used for agriculture, and most of that for thirsty crops like alfalfa, which is mainly grown for cattle, both in the U.S. and overseas.” The simple solution would be to raise prices on water such that it disincentivizes growing water hungry crops than alfalfa for example. The west’s water crisis is less about cities…

The reason this doesn’t happen is that farmers/farming lobbies have a lot of political power, especially in rural districts and no politician wants to be painted as anti-farming interests.

[deleted]

Re: Big water cutbacks ordered amid Colorado River shortage

#24

Post by bushbaba »

no_wizard wrote: post #3

Could we feasibly just run desalination stations from the coasts and pipe the water - like oil - to fill up these reservoirs? Setting cost aside for a second, is there any reason not to do something like this?

Why not pipe the water from the pacific northwest, similar to what was done with the Colorado river.

Re: Big water cutbacks ordered amid Colorado River shortage

#26

Post by bushbaba »

no_wizard wrote: post #8
2OEH8eoCRo0 wrote: post #4

Earlier quoted context omitted.

Setting cost aside? No. It costs a lot because it requires lots of energy which probably means lots of fossil fuels burning.

There’s other ways to mitigate that cost. Israel for instance runs many desalination plants from if I recall correctly solar power. We could do the same with solar and wind. Never the less, yes, because I believe cost can be managed and figured out over time, where as I don’t know what other mitigating factors would be the consequence of such a choice

Israel also recycles 90% of it's water. It first goes to urban use, then it's recycled for agriculture. California could do the same. https://www.waterworld.com/wastewater/article/16202781/israe...

Re: Big water cutbacks ordered amid Colorado River shortage

#27

Post by wolverine876 »

ar813 wrote: post #10

The answer to this problem lies here: “Entsminger pointed out that roughly 80% of the river’s flow is used for agriculture, and most of that for thirsty crops like alfalfa, which is mainly grown for cattle, both in the U.S. and overseas.” The simple solution would be to raise prices on water such that it disincentivizes growing water hungry crops than alfalfa for example. The west’s water crisis is less about cities…

Yes, market prices on water and beef (incorporating what are now climate externalities) would seem to solve these problems. Why isn't that being considered? Remember when conservatives, neo-liberals, and libertarians supported the market as a solution for everything?

Of course, we would need a reasonable amount of water available to consumers at below-market rates.

Re: Big water cutbacks ordered amid Colorado River shortage

#28

Post by joshuaheard »

Too bad the California Coastal Commission just denied the permit for a desalinization plant in Huntington Beach at the site of a decommissioned steam plant and reusing some of its infrastructure. It would have provided water to several Southern California cities.

https://californiaglobe.com/articles/california-coastal-comm...

Re: Big water cutbacks ordered amid Colorado River shortage

#29

Post by swatcoder »

ar813 wrote: post #10

The answer to this problem lies here: “Entsminger pointed out that roughly 80% of the river’s flow is used for agriculture, and most of that for thirsty crops like alfalfa, which is mainly grown for cattle, both in the U.S. and overseas.” The simple solution would be to raise prices on water such that it disincentivizes growing water hungry crops than alfalfa for example. The west’s water crisis is less about cities…

> The simple solution > The obvious answer

This community seems like its at its best when it expresses humble curiosity and its worst when it shuts the door on learning by oversimplifying deeply complex matters as though nobody else had the sense to look straight at them.

Water rights carry a legacy of centuries of personal and political history and thousands of competing interests. The levers with which to control price and set incentives the way you suggest don’t exist.

There are real problems looming, but there are no “simple solutions” or “obvious answers” being missed.

Whatever comes will involve great compromise and very few will think it was the right solution. I guess maybe you’re just joining that chorus early.

Re: Big water cutbacks ordered amid Colorado River shortage

#30

Post by [deleted] »

MengerSponge wrote: post #22
no_wizard wrote: post #3

Could we feasibly just run desalination stations from the coasts and pipe the water - like oil - to fill up these reservoirs? Setting cost aside for a second, is there any reason not to do something like this?

It would require a tremendous amount of energy. Lake Powell is more than 1km above sea level, which means each liter of water would require 10kJ just in gravitational potential energy. The reclamation effort is 1 maf (million acre-feet) of water over a year, which if supplied continuously from sea level with perfectly efficient pumping and transport corresponds to ~10 GW of power. A typical nuclear power plant genera…

[deleted]
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