This spring, Magdalena, New Mexico, ran out of water. The same thing happened in the West Texas town of Barnhart, where on top of a long-lasting drought, oil and gas drilling operations have sucked the local supply dry. By late June, more than 40 percent of the lower 48 states were suffering from moderate to severe drought.

The world's supply of freshwater is limited—and trickling away. More than two-thirds of it is tucked inside rapidly melting glaciers. Another 30 percent is hidden in underground aquifers, many of which are being depleted by the demands of agriculture, which accounts for 70 percent of worldwide freshwater use. Only half of 1 percent of the planet's freshwater is found in lakes, rivers, and streams.