Ancient aquifers are some of the most important, and delicate, water sources out West.

Communities that rely on the Colorado River are facing a water crisis. Lake Mead, the river’s largest reservoir, has fallen to levels not seen since it was created by the construction of the Hoover Dam roughly a century ago. Arizona and Nevada are facing their first-ever mandated water cuts, while water is being released from other reservoirs to keep the Colorado River’s hydropower plants running.

If even the mighty Colorado and its reservoirs are not immune to the heat and drought worsened by climate change, where will the West get its water?

There’s one hidden answer: underground.

Click here to read what Popular Science says about ancient groundwater

BY GRUNES ET AL./THE CONVERSATION |