In hot water: Looming water shortages in the American Southwest

In the West, it has been another terrible year for snowpack, with record low levels up and down the mountain ranges that sustain flow in rivers during the dry summers that characterize the region.  For instance, the Sierra Nevadas and Cascades are experiencing record low snowpack levels.  Snowpack at Crater Lake National Park is 80% below average, almost 7 feet less snow than the long term levels.  Though the total amount of precipitation is at normal levels, it is increasingly falling as rain rather than snow, greatly affecting water availabilty in the summer season.  The multi-year drought continues in California and other parts of the Southwest, as well as parts of Oregon and Washington.

The Colorado River near Moab, Utah. Photo credit: Angela Strecker

Nowhere is the conflict for water more intense than in the Colorado River Basin, which is also experiencing a prolonged drought.  The Colorado River is one of the most highly allocated rivers in the world, with >30 million people dependent on it’s flows.  However, a large part of the river’s water goes to irrigate agriculture, leaving little for large and growing urban population centers like Phoenix, Las Vegas, and Los Angeles, which all depend on water from the river.  Flows from the Colorado River were allocated to states in the upper basin (Colorado, Utah, Wyoming, New Mexico) and the lower basin (Arizona, Nevada, California) in a period of abnormally high flows, meaning that in many years, the river falls short.

The desert sucker, a fish native to the Lower Colorado River Basin. Photo credit: Thomas Pool

The fate of native fishes is intertwined with this water conflict: dams, reservoirs, and canals have greatly altered the timing and magnitude of flows in the river.  These changes, as well as the introduction of over 100 non-native fish species to the basin, have precipitated the demise of this unique fish community.  Over half of the fish species native to the Lower Colorado Basin are listed as either endangered or threatened under the federal Endangered Species Act, with an additional 15% of species being species of concern or candidates proposed for listing.  Conservation actions for these species will be met with a number of significant challenges, not the least of which is deciding how to balance water needs for fish versus water needs for people.

Writer Brandon Loomis explores some of these ideas in a new series for the Arizona Republic, “As the River Runs Dry“, shedding light on an important conflict between humans and their environment.

The Colorado River in Grand Canyon National Park. Photo credit: Angela Strecker