#Drought’s Spillover Effect in the American West — Circle of Blue #ColoradoRiver #COriver #aridification

Click the link to read the article on the Circle of Blue website (Brett Walton). Here’s an excerpt:

The American West has been plumbed into a series of “mega-watersheds.”

Because basins are connected by pipelines and canals, drought in one region affects distant watersheds.

A big Southern California water agency plans to draw more water from the Colorado River this year because of inadequate moisture in the Sierra Nevada.

On a map that might grace the walls of a high school classroom, the watersheds of the American West are distinct geographical features, hemmed in by foreboding plateaus and towering mountain ridges. Look closer and those natural boundaries are less rigid. A sprawling network of pipelines and canals pierce mountains and cross deserts, linking many of the mighty rivers and smaller streams of the West. These “mega-watersheds” have redrawn the map, helping cities and farms to grow large and productive, but also becoming political flashpoints with steep environmental costs…

Upstream on the Colorado River, there are more links. Tributary streams in Colorado are diverted through the San Juan-Chama Project into New Mexico, where the water enters the Rio Grande system and supplies Albuquerque and Santa Fe. The Central Utah Project pulls Colorado River water into the orbit of the fast-growing Wasatch Front, which is not in the basin.

In the headwaters state of Colorado, 11 major interbasin transfers unite rivers on both sides of the Rockies. The Moffat and Adams tunnels cut through the Continental Divide, a feat of engineering that brings Colorado River water into the South Platte River basin, where it is gulped by Denver and other Front Range cities.

The Moffat Tunnel, heading east. Photo: Brent Gardner-Smith/Aspen Journalism

Entrance to the Colorado-Big Thompson project. Photo: Brent Gardner-Smith/Aspen Journalism

For all the water supply flexibility they provide, these diversions are not risk-free. They have depleted water for native fish. Many of them — from the Owens River in California to the West Slope of Colorado — contend with legacies of acrimony and mistrust, feelings that arose decades ago due to the political imbalance between rural areas where water was extracted and urban areas that benefitted.