US data centers tripled annual water consumption to 17B gallons • Hacker News Board

Re: US data centers tripled annual water consumption to 17B gallons

#21

Post by myrmidon » Tue, Aug 25, 2026, 1:47 PM UTC

bell-cot wrote: post #2

Context: 1 acre-foot, a usual unit of measure for agricultural water, is a bit under 1/3 of a million gallons. 17B gallons is about 52k acre-feet. Vs. just the state of Arizona's historic water allocation, from just the Colorado River system, is over 2M acre-feet. Which, if you're familiar, has created a whole industry of growing extremely water-hungry but rather low-value crops in the desert . The latest Federal pla…

Completely agree. Specifically:

If you are anti-datacenter, then the water argument might look appealing to you, but its NOT a good argument, and it makes not only look you like an innumerate idiot, it also negatively impacts adjacent environmental movements/concerns.

So don't push it.

Re: US data centers tripled annual water consumption to 17B gallons

#22

Post by dgellow » Tue, Aug 25, 2026, 1:47 PM UTC

zug_zug wrote: post #12

whycome wrote: post #3

What does it mean to be consumed in this context? After used for cooling isn’t it clean enough for drink and other uses? Can’t it go back into other systems? Can’t it be used for agriculture?

"consumed" means it was used for evaporated cooling and let off into the atmosphere. It's obviously a resource that replenishes, but wells replenish at a limited rate [and can run dry] so it's not a negligible issue. Feel free to google this yourself, or ironically ask an AI, it'll happily confirm it's a real issue.

There is also the issue that evaporated water doesn’t necessarily go back to the original water source

Re: US data centers tripled annual water consumption to 17B gallons

#23

Post by sokoloff » Tue, Aug 25, 2026, 1:47 PM UTC

avalys wrote: post #6

This is a manufactured propaganda issue by dishonest and/or innumerate people. However, can’t data centers just use closed-loop cooling and avoid this whole thing? With all the money going into AI, it’s hard to imagine it being prohibitively costly.

With regards to evaporative cooled DCs (either primarily cooled that way or assisted some of the time): Imagine an air conditioner that instead of requiring energy to drive the compressor to make the phase change work, all the phase change was provided by taking in liquid water and evaporating it off as vapor, taking the latent heat of vaporization (2257 kJ/kg or 970 BTU/lb) with it.

Re: US data centers tripled annual water consumption to 17B gallons

#24

Post by quickthrowman » Tue, Aug 25, 2026, 1:48 PM UTC

zug_zug wrote: post #12

whycome wrote: post #3

What does it mean to be consumed in this context? After used for cooling isn’t it clean enough for drink and other uses? Can’t it go back into other systems? Can’t it be used for agriculture?

"consumed" means it was used for evaporated cooling and let off into the atmosphere. It's obviously a resource that replenishes, but wells replenish at a limited rate [and can run dry] so it's not a negligible issue. Feel free to google this yourself, or ironically ask an AI, it'll happily confirm it's a real issue.

What if it’s in an area where there is abundant surface water and 40” of precipitation per year? Not every data center pumps groundwater.

Re: US data centers tripled annual water consumption to 17B gallons

#25

Post by paxys » Tue, Aug 25, 2026, 1:48 PM UTC

thevinter wrote: post #13

Irrespective of how this number is calculated, whether is blue/green water etc here is some comparison data for context, since I personally think that hearing big numbers without any point of reference is pointless. Annual withdrawals (2015) - Thermoelectric power: ~48.5 trillion gal - Irrigation: ~43.1 trillion gal - Public supply: ~14.2 trillion gal - Self-supplied industrial: ~5.4 trillion gal - Aquaculture: ~2.76…

Almond farming - ~1.5 trillion gal (1.1 gal per almond)

Re: US data centers tripled annual water consumption to 17B gallons

#26

Post by bryanlarsen » Tue, Aug 25, 2026, 1:49 PM UTC

zug_zug wrote: post #12

whycome wrote: post #3

What does it mean to be consumed in this context? After used for cooling isn’t it clean enough for drink and other uses? Can’t it go back into other systems? Can’t it be used for agriculture?

"consumed" means it was used for evaporated cooling and let off into the atmosphere. It's obviously a resource that replenishes, but wells replenish at a limited rate [and can run dry] so it's not a negligible issue. Feel free to google this yourself, or ironically ask an AI, it'll happily confirm it's a real issue.

That's a small portion of the consumption. According to the article, the vast majority of the water is for electricity generation, and the vast majority of that water is from hydroelectric power generation. Hydroelectric generation does not evaporate the water, it releases it downstream in a clean, usable form.

Re: US data centers tripled annual water consumption to 17B gallons

#27

Post by elil17 » Tue, Aug 25, 2026, 1:49 PM UTC

avalys wrote: post #6

This is a manufactured propaganda issue by dishonest and/or innumerate people. However, can’t data centers just use closed-loop cooling and avoid this whole thing? With all the money going into AI, it’s hard to imagine it being prohibitively costly.

People have always used a closed loop to move heat in and out of the data hall - but something has to keep that closed loop cool. That's often a cooling tower which uses evaporating water to reject heat into the air in a way that's very energy efficient.

Additionally, the power plants which supply electricity to the data centers have the same cooling problem. They also typically use cooling towers.

It's not dishonest at all. Datacenters and fossil fuel power plants are absolutely evaporating fresh water for cooling. The piece that's missing from that discussion is that it helps them use less electricity.

Re: US data centers tripled annual water consumption to 17B gallons

#28

Post by dgellow » Tue, Aug 25, 2026, 1:51 PM UTC

myrmidon wrote: post #21

bell-cot wrote: post #2

Context: 1 acre-foot, a usual unit of measure for agricultural water, is a bit under 1/3 of a million gallons. 17B gallons is about 52k acre-feet. Vs. just the state of Arizona's historic water allocation, from just the Colorado River system, is over 2M acre-feet. Which, if you're familiar, has created a whole industry of growing extremely water-hungry but rather low-value crops in the desert . The latest Federal pla…

Completely agree. Specifically: If you are anti-datacenter, then the water argument might look appealing to you , but its NOT a good argument, and it makes not only look you like an innumerate idiot, it also negatively impacts adjacent environmental movements/concerns. So don't push it.

It’s more nuanced, the water consumption can be a real local problem. The evaporated water doesn’t necessarily come back to the original source, and if the water supply was already stressed you’re adding even more pressure to it. You have to look about the actual details, like all arguments about resource consumption

Re: US data centers tripled annual water consumption to 17B gallons

#29

Post by shimman » Tue, Aug 25, 2026, 1:52 PM UTC

paxys wrote: post #25

thevinter wrote: post #13

Irrespective of how this number is calculated, whether is blue/green water etc here is some comparison data for context, since I personally think that hearing big numbers without any point of reference is pointless. Annual withdrawals (2015) - Thermoelectric power: ~48.5 trillion gal - Irrigation: ~43.1 trillion gal - Public supply: ~14.2 trillion gal - Self-supplied industrial: ~5.4 trillion gal - Aquaculture: ~2.76…

Almond farming - ~1.5 trillion gal (1.1 gal per almond)

I value almonds more than LLM slop.

Re: US data centers tripled annual water consumption to 17B gallons

#30

Post by otterley » Tue, Aug 25, 2026, 1:52 PM UTC

zug_zug wrote: post #20

RajT88 wrote: post #7

Earlier quoted context omitted.

Most of those partisans have no idea what other sources of water consumption are by magnitude. They seem to quote any number as if it is a lot. A billion gallons is a lot. 500000 gallons is not a lot.

Each datacenter uses as much water as 1,000 homes. You're welcome to put such resource constraints in your own local community if you don't care about the increased demand.

On the other hand, many homes could mothballing a misplaced farm provide water for?

As far as I know, there's not a single place in the world where someone went without water to cook, drink, or bathe because a data center consumed it.