There are any number of reasons to argue against the current infrastructure build-out and the eventual draw on resources that may, or may not, be better used elsewhere but the water issues, except for draining aquifers, don't really matter.
Draining aquifers for pretty much anything other than drinking water is dumb. Draining aquifers for agriculture is insanity. And we do so much of it that the result can actually be measured as a contributor to sea level rise.*
From Andy Masley's substack, October 11, 2025:
AI data centers use water. Like any other industry that uses water, they require careful planning. If an electric car factory opens near you, that factory may use just as much water as a data center. The factory also requires careful planning. But the idea that either the factory or AI is using an inordinate amount of water that merits any kind of boycott or national attention as a unique serious environmental issue is innumerate. Individual data centers can sometimes stress local water systems in the way other industries do, but when you use AI, you are not contributing to a significant problem for water management compared to most other things you do in your day to day life. On the national, local, and personal level, AI is barely using any water, and unless it grows 50 times faster than forecasts predict, this won’t change. I’m writing from an American context and don’t know as much about other countries. But at least in America, the numbers are clear and decisive.
The idea that AI’s water usage is a serious national emergency caught on for three reasons:
People get upset at the idea of a physical resource like water being spent on a digital product, especially one they don’t see value in, and don’t factor in just how often this happens everywhere.
People haven’t internalized how many other people are using AI. AI’s water use looks ridiculous if you think of it as a small marginal new thing. It looks tiny when you divide it by the hundreds of millions of people using AI every day.
People are easily alarmed by contextless large numbers, like the number of gallons of water a data center is using. They compare these large numbers to other regular things they do, not to other normal industries and processes in society. They aren’t aware of how much water society uses on other normal industries.
Together, these create the impression that AI water use is a problem. It is not. Regardless of whether you love or hate AI, it is not possible to actually look at the numbers involved without coming to the conclusion that this is a fake problem. This problem’s hyped up for clicks by a lot of scary articles that completely fall apart when you look at the simple easy-to-access facts on the ground. These articles have contributed to establishing fake “common wisdom” among everyday people that AI uses a lot of water.
This post is not at all about other issues related to AI, especially the very real problems with electricity use. I want to give you a complete picture of the issue. I think AI and the national water system are both so wildly interesting that they can be really fun to read about even if you’re not invested in the problem.
Importantly, I am not saying that it’s impossible for data centers to ever cause any problems with water. They require careful planning in the same ways other large industrial buildings do. What I am saying is that right now no reasonable forecasts imply that data centers will rise to become a significant problem for water access in the US. Almost all complaints about their national water use are basically just saying “We should not have a new large industry in America using water.” The tax revenue per gallon from data centers is just so high that in many places they are among the best new buildings possible to benefit a community experiencing water scarcity, because any other industries using the same amount of water would generate way less tax revenue. Critics of data centers need to carefully weigh their water costs against the massive amounts of revenue they can bring in for everyday people, not just look at the water costs alone. The debate about building data centers should involve reasonable conversations between ecologists, economists, and city officials, not everyday voters shouting down local meetings with misleading statistics.
Contents
AI water use isn’t an issue on the national, local, or personal level
How big of a deal is it that data centers use potable water?
Using AI can save way more water than is used in data centers
The social value or harm of a tool isn’t the final word on how harmful it is to the environment
What about all those news stories about AI harming local water access?
A few important definitions
Suppose I take a cup of water from a lake, and then immediately dump it back in. That doesn’t seem bad. Now I take a cup from the lake, and this time I evaporate it. That seems worse. Now I take a cup and spend some resources on making it drinkable. These all have very different costs and effects on the water system. We need words to describe it.
Water is complicated, but not too complicated. There are a few key definitions to understand. First:
Consumptive use removes water from a local system. Taking the cup of water and evaporating it is consumptive use. Evaporated water mostly does not return to its original source.
Non-consumptive use temporarily takes water from a local system, and returns it later unaffected. Taking the cup of water from the stream and pouring it back in is non-consumptive use.
Growing food is an example of consumptive use. Some of the water becomes part of the food itself. When the food is shipped away, the water leaves the local system.
Many data centers rely on evaporative cooling. This is the way water is consumptively used in data centers. They do not immediately evaporate all the water they are using. Most of it circulates through the cooling system repeatedly before evaporation.
Many reports on AI’s water use do not only include water in data centers, they also include the water consumed by the power plants data centers draw from. This leads to a second important distinction....
....MUCH MORE
HT: UnDark's "How Much Water Do AI Data Centers Really Use?", December 18.
And the aquifers? Last seen in May 2024's "Over a third of urban Chinese live in sinking cities":
....In fact people are depleting aquifers at such a rate that the H₂O that moves through the water cycle actually ends up in the oceans, raising sea levels. Not huge but measurable.
From the U.S. Geological Survey:
...Estimated global groundwater depletion during 1900–2008 totals ~4,500 km3, equivalent to a sea-level rise of 12.6 mm (>6% of the total). Furthermore, the rate of groundwater depletion has increased markedly since about 1950, with maximum rates occurring during the most recent period (2000–2008), when it averaged ~145 km3/yr (equivalent to 0.40 mm/yr of sea-level rise, or 13% of the reported rate of 3.1 mm/yr during this recent period)....
We pay pretty close attention to water and in the decade since we started pitching Nvidia we've had only two "water and AI" posts
August 2025 - "AI Data Centers in Texas Used 463 Million Gallons of Water, Residents Told to Take Shorter Showers"
And October 2025 - "Opportunity: "Next-Gen AI Needs Liquid Cooling" which has such tidbits as:
....“The average power density in a rack was around 8 kW,” says Josh Claman, CEO of the startup Accelsius. “For AI, that’s growing to 100 kW per rack. That’s an order of magnitude. It’s really AI adoption that’s creating this real urgency” to figure out a better way to cool data centers.
Specifically, the urgency is to move away from fans and toward some sort of liquid cooling. For example, water has roughly four times the specific heat of air and is about 800 times as dense, meaning it can absorb around 3,200 times as much heat as a comparable volume of air can. What’s more, the thermal conductivity of water is 23.5 times as high as that of air, meaning that heat transfers to water much more readily.
“You can stick your hand into a hot oven and you won’t get burned. You stick your hand into a pot of boiling water and you can instantly get third-degree burns,” says Seamus Egan, general manager of immersion cooling at Airedale by Modine. “That’s because the liquid transfers heat much, much, much, much more quickly.”....
On the other hand we have dozens of posts on H2O.
From trying to figure out various bets on water to: September 2019's - Water and Its Mysteries:
There are very few things that modern science does not understand. One of them is consciousness; the other is water.1 In the case of consciousness, the hard problem is designing good experiments; in the case of water, finding a theory that explains its properties.*Archive.org: The Left Hand of the Electron - Isaac Asimov
Thermodynamic theories assume that any substance may be characterized by its internal energy U(S,V), where S and V are extensive variables, S is a measure of the number of accessible quantum states at a given temperature T, and V is a measure of the spatial extension of the system at a given pressure p. By the first law of thermodynamics dU(S,V) = T·dS – p·dV. Every substance has an equation of state (EoS) p = kBT·[1/V + B2(T)/V2 + …], where kB = 0.0138 zJ·K–1 is a universal constant. B2(T) is negative at low temperature and positive at high temperatures. At B2(T) = 0, attractive and repulsive forces are in balance. For an ideal gas, B2(T) = 0; for a system of hard spheres of diameter σ, B2(T) = 2π·σ3/3; for a van der Waals gas, B2(T) = b – a/kBT, with b and a measuring the repulsive and attractive forces between molecules.
Let MW designate molecular weight. The substance displaying the greatest ratio TB/MW = 80(8) K·Da–1 is water (H2O), followed by hydrogen fluoride (HF), and ammonia (NH3). TB/MW thus corresponds to the density of cohesive energy. The fact that water is an elixir for life is perfectly justified from a thermodynamic point of view. In chemistry, such high densities are usually associated with abnormally high ebullition points.
A phase diagram in the plane represents the domains where a substance may exist as a solid, liquid, or gas. Domain boundaries are marked by coexistence lines. It is there that two phases coexist. Substances undergo first-order transitions at coexistence lines; the system absorbs or releases energy, giving rise to discontinuous changes in volume and density. The sublimation line is the locus of points where a solid coexists with a gas and may extend from zero to the triple-point temperature T3. In the case of water, this triple point is observed at T3 = 0.01°C = 273.16 K and p3 = 611 Pa = 0.006 atm. The melting line is the locus of points from T3 to an infinite temperature. These phases have different symmetries. Full rotational invariance in the liquid phase turns into discrete symmetries in the crystal phase. The condensation line is the locus of points where a gas coexists with a liquid and extends from T3 to a critical point C. Above C, only a single-phase homogenous system exists. In the case of water, this critical point is observed at TC = 373.946°C = 647.096 K and pC = 22.06 MPa = 217.7 atm. This critical point occurs as soon as two phases share the same symmetry group.....MUCH MORE
Regarding Asimov, though he made his money writing science fiction he was a trained chemist: PhD, Columbia, post doc, taught biochem at Boston Uni's Med school etc.
And he was fascinated by water. See after the jump.
That's from December 30, 2020's "Hydrogen Storage: A New Form Of Ice" which has this outro:
One of Asimov's riffs on water, "Not as We Know it: The Chemistry of Life" he uses this little paragraph as a jumping-off point:
Water is an amazing substance with a whole set of unusual properties which are ideal for life-as-we-know-it. So well fitted for life is it, in fact, that some people have seen in the nature of water a sure sign of Divine providence. This, however, is a false argument, since life has evolved to fit the watery medium in which it developed. Life fits water, rather than the reverse.
In his book "The Left Hand Of the Electron" Dr. A gathers essays he had written over the years:
- The Thalassogens
-
Subject: common liquids
First Published In: Dec-70, The Magazine of Fantasy and Science Fiction
Collection(s):
- 1972 The Left Hand of the Electron
Cold Water-
Subject: freezing of water
First Published In: Feb-71, The Magazine of Fantasy and Science Fiction
Collection(s):
- 1972 The Left Hand of the Electron
Hot Water-
Subject: boiling points
First Published In: Jan-71, The Magazine of Fantasy and Science Fiction
Collection(s):
- 1972 The Left Hand of the Electron
If interested, here's the book at Archive.org. I did a quick search and saw 114 hits for 'water'.
So yeah, we pay attention to water.
