Will Hewes

Will Hewes is the Water Sustainability Lead at Amazon, and his job is the one most tech companies only started worrying about once their data centers got thirsty: making sure all the water those machines drink gets paid back. He runs the program behind AWS's commitment to be water positive by 2030, which simply means returning more water to the communities and watersheds Amazon operates in than its data centers withdraw. It is a big promise from one of the largest computing operators on the planet, and Hewes is the person who has to make the arithmetic add up.

Will Hewes did not come to that job through a corporate sustainability ladder, which is part of what makes him worth listening to. He started in river conservation, spending five years at the nonprofit American Rivers in Washington, then moved into water-infrastructure finance as a director at Table Rock Infrastructure Partners, with an MBA from Berkeley's Haas school in between. So when he talks about water, he is talking about something he has worked on from the policy side, the money side, and now the operator side, and that shows up as a refreshingly unglamorous way of framing the problem. As he put it on the show, the goal is not the best technology you could ever imagine, but what you can reliably implement today.

Will Hewes explains the AWS approach as efficiency first, offsets second. The data centers use a design called direct evaporative cooling, which mostly cools the building with outside air and only sips water on the hottest days, so little that in places like Northern Europe it runs less than 5% of the year. About 24 of Amazon's data centers already run on recycled water piped through what the industry calls purple pipe, a deliberately different-colored pipe so nobody confuses it with the drinking-water system. Only once a site is as lean as it can be does the program turn to replenishment, because, in his words, the company refuses to use replenishment as a way to give itself a pass.

Will Hewes treats replenishment as collaboration rather than a press release, which is the detail I found most telling. The program now runs about 24 replenishment projects that will deliver 7.6 billion liters of water once complete, from converting Chilean farmers from flood to drip irrigation with the climate-tech company Kilimo, to monitoring the results with a startup called Waterplan, to co-investing in an Ohio wetland alongside Google. He is candid that he does not see water as a competitive arena, talking openly with the stewardship teams at rival tech giants, and you can read the broader case for corporate water stewardship over on the Leviathan database that I keep on the sector.

Will Hewes grew up on the coast of Maine, where, in his telling, water was at the core of his childhood, and he has circled back to it: he now lives in Portland, Maine and sits on the board of trustees of the Portland Water District. Ask him where the real opportunity in water is and he points past the headline technologies to direct water reuse, a drought-proof resource we keep throwing away, and ask him what holds the sector back and he gives a one-word answer that has nothing to do with chemistry: inertia.

“Part of what I think about sustainability is not what's the best possible technology you could ever think of, but what can you reliably implement today.”

That instinct, paired with a career spent on every side of the water problem, is most of why Amazon's water-positive math has a real shot at adding up.