Decoupling consumption
Southwestern cities shrink their water footprint even as they grow

When we think about the Colorado River water shortage, it’s natural to blame it on the booming desert population in cities like Phoenix, Las Vegas and Los Angeles. Too many people are sucking up too much water to keep their lawns green and swimming pools full. And as more people move to these cities, overall water consumption increases proportionately. 

This pattern held true for eight decades after the 1922 signing of the Colorado River Compact. People relying on the river shot up from less than 1 million to nearly 40 million, and overall water consumption climbed as well, peaking at just under 20 billion cubic meters in 2000.

But then, according to a new study in the Journal of Water Resources Planning and Management by Brian Richter, the pattern was broken. Even as the population continued to shoot up, consumption of Colorado River water actually dropped and then plateaued. That is to say, water use and population growth were decoupled.  

Although the finding is counterintuitive, it won’t come as a surprise to those who have been paying attention. The crisis is rooted in an already overtaxed river diminished by the most severe drought in the last 1,800 years.

Richter’s study not only confirms that but also shows how, when faced with hard limits, we can reduce consumption without compromising quality of life. 

Richter evaluated water use by 28 municipalities that collectively serve about 23 million people. More than half had reduced per capita water use enough to decrease total water deliveries by 18%, even as populations grew by 24%. Albuquerque, Fort Collins, Phoenix, Los Angeles and San Diego all followed the trend. Perhaps the most impressive was the least expected: Las Vegas added nearly 1 million residents between 2000-20, yet water deliveries dropped by more than 10%, during that same time. In other words, the land of conspicuous overconsumption cut water consumption in half. 

So does this mean Las Vegans are suffering from perpetual dehydration? Have the golf courses turned to sand? Have the Bellagio fountains gone dry? Nope, (at least not yet). I’d bet most Las Vegans don’t even notice the difference in their own water use, though they might have sensed the gradual disappearance of ornamental turf around the city. Same goes for other cities with big savings. 

That’s because they are realizing these consumption cuts not by rationing water, but by implementing system-wide efficiencies and incentives. New ornamental turf is banned in many places, and folks are paid to remove existing turf. Same goes for switching to more efficient appliances. Most Las Vegas golf courses are irrigated with treated wastewater, and high-tech leak-detection systems save hundreds of millions of gallons per year.

One of the reasons Las Vegas and other cities were able to make such big gains is because there was so much waste to begin with. Much of the low-hanging fruit has been plucked, but some still remains: Las Vegas’ top residential water users – ultra-wealthy mansion owners – still use tens of thousands of gallons per day; water pricing structures are not adequately progressive; and Nevada’s accounting system disincentivizes indoor water conservation.

Here are some interesting numbers:

• 1.3 million gallons: Daily water use by the Venetian Resort in Las Vegas, the metro’s largest commercial user.

• 35,646 gallons: Daily water use by Trophy Hills, the Las Vegas mansion owned by the late Sheldon Adelson. 

• 25,682 gallons: Daily water use by the 75,000-square-foot Henderson, Nev., mansion of EBay founder Pierre Omidyar. 

• 112 gallons: Average total daily per capita water use in Las Vegas (includes residential, commercial industrial)

• 30 million gallons: Daily water loss to evaporation at Lake Powell in July. 

So even Las Vegas still has ample room for cuts. Meanwhile, some cities remain ridiculously wasteful — we’re looking at you, Farmington, St. George and Scottsdale. The good news is that if these smaller cities follow the larger metros’ leads, they could realize significant cuts. The bad news is that it still won’t be nearly enough to save the Colorado River on which so many depend. 

And even if population and water consumption have been partially decoupled, they aren’t completely divorced. Las Vegas, Phoenix and L.A. eventually will hit a limit of per capita cuts, at which point a growing population will again cause overall consumption to increase. Thing is, there is no extra water in the system to sustain it, and the old practice of cities “buying and drying” farms and transferring water rights to new housing development is untenable. Any agricultural water saved through efficiency, fallowing or crop changes must go back to the river, not to new subdivisions. 

For the past century, the Southwestern Growth Machine – fueled by greed, cheap and dirty power, and the mirage of abundant water – has churned away relentlessly. Now it’s time to shut it down and practice not only water consumption-control, but also growth control – decoupling or not.

The Land Desk is a newsletter from Jonathan P. Thompson, longtime journalist. To subscribe, go to landdesk.org ?