Laura Bliss is CityLab’s West Coast bureau chief. She also writes MapLab, a biweekly newsletter about maps (subscribe here). Her work has appeared in The New York Times, The Atlantic, Sierra, GOOD, Los Angeles, and elsewhere, including in the book The Future of Transportation.
Drought isn’t just about supply—it’s also about demand.
It’s not just summer’s slow news cycle generating premature coverage. Knowing in advance the likelihood and severity of El Niño precipitation can give officials time to take preparatory measures for bridges and roads. And in the West, city officials, farmers, and lawn enthusiasts alike all want to know when they’ll have their water back.
But the question of how much water will “end” the drought isn’t really the right one to ask. (I tip my hat to Brett Walton, who makes this point beautifully on the water-news site Circle of Blue.)
There have been attempts at calculations, most recently by the executive directors of the environmental design organization Arid Lands Institute. Based on a statewide groundwater deficit of 63 trillion gallons (a conservative figure, based on 2013-2014 satellite measurements), Hadley and Peter Arnold estimate that the state needs at least eight or nine very large storms, each as potent as the system that dumped 10 trillion gallons on the state over 10 days last December.
The trouble is, defining drought isn’t as simple as how much groundwater has been lost, or how low reservoirs are. It’s a matter of supply and demand. When we cross our fingers for El Niño’s rainy redemption, we’re only only focusing on supply, and only one source of supply. When we talk about what it’ll take to “end the drought,” we need to talk about human demand, too.
The Arnolds recognize this, to an extent, by basing their math off of the groundwater deficit, to which humans contribute mightily. But any form of calculation implies that we’re solving for some water-secure constant. In fact, a lot of research implies that drought is the new normal for California, and much of the Western U.S. That’s because climate conditions are changing. In some places, it might also be because demand has overreached supply. Particularly as California’s population grows, it’s almost impossible to imagine a day where cities, farms, and individuals no longer have to adapt to nature’s fluctuations and to each others’ needs.
“We should take steps to include the human aspects of drought,” Anne F. Van Loon, a hydrologist and lecturer at the University of Birmingham, told Walton. “We can have a drought in a relatively wet situation.”
That’s not to say that a strong El Niño wouldn’t help the situation California’s facing now. But it’s an important point to keep in mind as we navigate this season’s El Niño speculation. That, and the fact that we really won’t know what to expect until at least late fall.