Pine Beetle Infestation Threatens Water Source for U.S. Southwest

The destruction of 2.5 million acres of Rocky Mountain forest because of a pine beetle infestation could threaten the water supplies of 33 million people, according to the U.S. Forest Service. Rick Cables, chief forester for the Rocky Mountain region, told a congressional committee that the dead and dying forest at the headwaters of the Colorado River could burn extensively and reduce water supplies to residents in Los Angeles, San Diego, Phoenix, and Tucson, Ariz. Roughly 25 percent of the water piped to these cities originates in national forests in the Rockies that have suffered extensive damage from infestations of pine bark beetles, Cables said. He said that the loss of the trees and subsequent wildfires would “literally bake the soil” and lead to excessive runoff and rapid snowmelt, both of which reduce flow to the Colorado River. The fires also could destroy reservoirs, pipes, and other infrastructure, Cables said. Outbreaks of pine beetles — which scientists attribute to warmer winters that fail to kill beetle larvae — have destroyed 8 million acres of trees in the western U.S. and 22 million acres in Canada.

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