AI Water Usage and Orders of Magnitude

I was well prepared for this, having read Simon's rollup of the AI water issue is fake, and sure enough not an hour has passed before I came across AI-related data centres use vast amounts of water. But gauging how much is a murky business from our friends at the CBC.

It would be less murky with some actual data!

Highlighting: Kathryn is concerned about a data centre planned to go into Nanaimo, British Columbia. She says that "similar-sized facilities can churn through 70,000 litres of potable water a day."

And that sounds like a lot! I know this because I told my 12 year old and his eyes went really wide. But let's look at some Nanaimo stats:

Area population (2021): 115,459
Water usage by individuals (2024): 179 litres per person per day
Total water usage (population times usage): 20,667,161 litres per day.

That's 295 times the amount of water Kathryn suspects the data centre will use, or about 0.3%.

Put another way, if 391 people moved into the area, it'd have equivalent impact. Interestingly, 10,523 people moved into the area between 2016 and 2021.

This is not a perfect comparison, and some uses of water are recaptured and some aren't. One can also make the point that we should look at all uses of scarce resources and restrict additions to this total whenever possible.

But reporting in the style of "oh no, big number is big" doesn't help anything without establishing a relative scale.