Data centers are far from being California's worst water-guzzlers: Bloomberg View


California agricultural operations are huge and taxing to water supplies, especially during drought. In this file photo from January, farm workers tend to young almond trees near Firebaugh, in the San Joaquin Valley.

(Sacramento Bee/Tribune News Service)

By Justin Fox

The data centers that our world increasingly runs on need water to stay cool. How much? "A midsize 15-megawatt center uses between 80 million and 130 million gallons of water a year for cooling, according to industry estimates," Drew Fitzgerald reported last week in the Wall Street Journal. Water-starved California has about 800 of these places. Multiply 800 times 130 million, and you get 104 billion gallons a year.

That sounds like a lot of water! But pay close attention to the unit of measurement. As Alexis Madrigal wrote in The Atlantic last year: "An unofficial rule of California water politics holds that if you want to make an amount of water sound large, use gallons. If you'd like to make it sound small, set your units to acre-feet or even million acre-feet."

Let's make it sound small. A midsize 15-megawatt data center uses 245 to 400 acre-feet of water a year for cooling. The statewide estimate of 104 billion gallons a year converts to 319,000 acre-feet. This could also -- awkwardly but not incorrectly -- be expressed as 0.3 million acre-feet a year. Which is nothing, right?

Well, not nothing. Overall agricultural, industrial, commercial and residential water use in California totals 40 million to 45 million acre-feet of water a year; data centers use about 0.8 percent of that. For a category of water use that barely existed two decades ago, that's significant.

It's a lot more significant, for example, than the 2,164 acre-feet of California water that Nestle puts into bottles every year -- a source of controversy in recent months. It's vastly more than the 214 acre-feet of water used last in year in California in another controversial endeavor, fracking for oil and gas.

On the other hand, it's nowhere near the more than 10 million acre-feet used each year in the state to grow food for livestock, the annual 3 million to 4 million acre-feet needed to keep California's almond trees producing, or the 3 million acre-feet of water going to outdoor residential uses such as lawns and pools. It's at least in the same ballpark as the 800,000 acre-feet used for large- scale landscaping, such as watering golf courses and parks.

Californians and consumers of California products have been learning a lot this drought year about how much water it takes to grow, produce, cool or keep alive various things. These revelations are usually expressed in gallons and geared toward eliciting a reaction of "Wow, that's a lot of water!"

Raising awareness of how much fresh-water use modern life requires has to be good, right? But there are important questions that should be asked after that initial shock. I've come up with four.

1. Is that really a lot of water?

The Wall Street Journal article on data centers includes a graphic that shows some other things that use 100 million to 130 million gallons of water a year: a hospital, two golf courses, a 100-acre almond orchard. Interesting, but not all that informative. Venture capitalist Marc Andreessen, in a Twitter reaction to the Journal article, found another comparison-- newsprint production nationwide uses up about as much water as California's data centers do. His point was that as information delivered via those data centers drives people away from newspapers, we might be getting some offsetting water savings. But California appears to have no newsprint mills, so this is irrelevant to its water picture.

What seems most important in the context of California's drought is whether a particular water use is a significant drain on resources. Data-center water use appears to be big enough to pay attention to, if perhaps not obsess over. Frackers' water consumption seems as if it isn't even worth talking about. Nestle's bottling operations have no noticeable statewide impact, although they may be a big drain on local water systems. Swimming pools, while seemingly emblematic of water profligacy, are actually not huge water users. And agriculture, of course, is by far the biggest water user of all.

2. Is it used to produce something of economic value?

Residential outdoor water use often fails this test. Lush lawns are aesthetically pleasing, but less-thirsty landscaping can be, too. And while it should be up to homeowners to decide what pleases them most, it should also be up to them to pay through the nose for much-higher-than-average water use. A state appeals court ruling in April made it harder for California water providers to charge tiered rates; let's hope they can find a way around that and force those water wasters to shape up. Bottled water seems pointless in a country with mostly safe municipal water, but people do pay for it so the convenience must have some value. Many California farmers argue that water flows reserved for keeping fish alive are an economic waste (in part because they have failed to keep the fish alive), but that's a complex issue best saved for another day.

As for data centers, Peter Gleick of the Pacific Institute estimated that in 2001 the high-tech sector in California produced $950,000 of gross state product for every acre-foot of water used. I'm not sure data centers per se would score that high (they're not exactly big employers), but the tech industry as a whole is hugely important to the state, and dramatically more productive per acre-foot of water used than agriculture (which generated $893 per acre-foot in 2001, according to Gleick, with crops such as rice and alfalfa much lower).

3. Could you do it with less water?

This has been a big question for operators of data centers. James Hamilton, who oversees the design of Amazon Web Services' data centers, has called their water consumption "super embarrassing," and efforts have been underway for several years to cut back or use recycled water. (In general, treated wastewater is the single biggest potential new water supply on the horizon for California -- about 670,000 acre-feet were reused in 2010, and there's potential for another 1.2 million to 1.8 million acre-feet per year.) And residential landscaping could use much less water.

Agriculture is complicated -- you simply can't grow crops without lots and lots of water, and trying to nudge farmers toward conservation by raising the price of water can have unexpected consequences. Almond orchards are big water users on a per-acre basis, but California farmers have been planting more and more of them as water has become less plentiful (a million acres total in 2014, up from 640,000 a decade ago) because they also bring in more dollars per acre than other crops.

4. Could you do it somewhere else?

For data centers, the answer is "Yes, but ..." There has already been a shift toward locating them where the weather is cooler and the water and electricity cheaper, but there are limits to how far they can be removed from the users of the cloud services they host. As long as California is the tech industry headquarters, it will probably still need lots of data centers.

With bottled water, it's nice to be close to customers too, but Nestle may eventually decide to get its water elsewhere.

Agriculture is the big question. Occasional water-supply problems aside, California is a spectacular place to grow lots and lots of crops. It's got a gigantic, flat, fertile, sun-baked valley at its center, coastal valleys with mild climates that are perfect for berries and lots of other fruits and vegetables, desert valleys near the Mexican border where summer crops can be grown in the winter, and hillsides where some of the world's great wine grapes can be planted. Still, there are those who argue that maybe other, wetter parts of the country -- the Southeast in particular -- should take over some of California's crop production.

Put all that together, and California's data centers seem like a pretty reasonable use of water. Not that they shouldn't use less -- and I haven't even gotten into their electricity consumption. But in a state that needs to reduce its water use, there are far juicier targets.

(c) 2015, Bloomberg View
Justin Fox is a Bloomberg View columnist writing about business.