See Why There’s No Drilling Our Way Out Of the Drought

Groundwater, streams, rivers, and lakes are all interconnected.
Jul 20, 2015·
Willy Blackmore is TakePart’s Food editor.

There was record rainfall in California in May, with parts of the state getting more than an inch and a half in just 90 minutes. But that wasn’t the rain that relieved some short-term concerns over the availability of water in the parched state, which is suffering from its worst drought in 1,200 years. Rather, it was storms in the Rocky Mountains that dumped “rain that was unprecedented in the modern historical record,” as the Los Angeles Times put it, that helped slightly refill the reservoirs that supply water to California and other arid Western states.

It’s only a slight silver lining, but it helps illustrate the complex nature of the water supply system that is the Colorado River, which supports 40 million people across the southwest. The river, and its mismanagement, has been the subject of a series from ProPublica and Matter called “Killing the Colorado.”

With water deliveries being cut in irrigation districts supplied by the Colorado and other watersheds, including the Sacramento–San Joaquin River Delta, farmers (and cities) are increasingly turning to groundwater supplies. But as a new video from the series released Friday shows, thinking of rainfall and subterranean reservoirs as separate entities is a grand mistake.

“These underground supplies are often connected to the rivers and lakes above. Drawing from one source can deplete the other,” the voiceover explains. “If we keep managing water this way, we put the whole system at risk.”

Scientists may understand the interconnectedness of the water system—that wells and streams can draw from the same source “is accepted as a basic principle of hydrogeology,” according to ProPublic. But the cause and effect isn’t taken into account when it comes to water policy and water rights.

In California, for example, surface water rights are controlled by a century-old system. Groundwater? The first law regulating it was passed last year—and it doesn’t require “groundwater sustainability” until 2040.

And the disconnect can be seen in California’s water deficit both below and above ground: As NASA hydrologist Jay Famiglietti told Capital Public Radio, “we need to replace about 12 trillion gallons of water in storage, in snow, in groundwater, in our reservoirs,” or three very wet years’ worth of rain.

As for groundwater alone? The state’s underground reservoirs have an 11 trillion gallon deficit of their own that needs to be replenished.