Colorado River Basin – Protecting the Flows

Drainage basin map of the Colorado River | Wikimedia Commons

One of our nation’s, and the world’s, greatest natural treasures, the Colorado River carves a spectacular course through the heart of the American southwest. The management history of the Colorado River and its tributaries is a complex one, and as the age-old Western expression says, “Whiskey is for drinking. Water is for fighting.” 

From its headwaters in northern Colorado, the river meanders through the desert southwest before crossing the border into Mexico. Along its way, it creates habitats for a remarkable spectrum of wildlife, over 1500 plant species, and, historically, 49 species of native fish. The river’s delta supports well over 300 species of birds, and is a major refuge for migratory species in particular.

Until 1998, the Colorado River stretched all the way from its source in the Rockies to Sea of Cortez. Now, it dries up in the Sonoran Desert miles before it reaches the sea. The Colorado River is the lifeline of the west, fueling economies in seven states where people use the river’s water for their material sustenance; millions more use the river itself for recreation. 

Thirty-six million people, from Denver to Los Angeles depend on Colorado River water. Under the Colorado River Compact, an interstate agreement signed in 1922, water from the Colorado is divided among the seven basin states. As a result, booming population centers like Los Angeles, Denver, Phoenix and Las Vegas have blossomed in the arid desert-region, dependent on the river to quench their thirst.

The Colorado River irrigates nearly 4 million acres of land, which grow 15% of the nation’s crops. Of the Colorado’s annual flow  78% is diverted for agricultural use.  By drawing water from the river, we have raised thousands of acres of crops in the desert, creating lush green fields where little would have grown naturally.

Millions of tourists flock to the banks of the River and its tributaries each year for boating, fishing, birding, hunting, and hiking which adds up to a $26 billion dollar recreation economy. The businesses and communities along the river are integral pieces of this economy, and many livelihoods depend on the health of the Colorado and its tributaries.

Four federally listed endangered species of fish still cling to existence in the river; its water and wetlands provide habitat for migrating birds from the top of the basin all the way to the bottom; and bighorn sheep, elk, mule deer, bear, and mountain lion prowl its banks.

Several multipurpose projects on the Colorado River system include power plants which generate electricity distributed throughout the West. The power is marketed by the Western Area Power Administration (Western) of the U.S. Department of Energy and is sold to “preference” customers – public entities such as municipalities or rural electric cooperatives. These hydro plants have a total generating capacity of 4.1 bn kilowatts (kW). These large dams have impacts on natural and cultural resources in Dinosaur National Monument, Black Canyon of the Gunnison National Park, Canyonlands National Park, Glen Canyon National Recreation Area, and Grand Canyon National Park.

The Colorado River is often called one of the most controlled and plumbed rivers on the planet and more dams, and diversions are planned, especially in the upper basin in Colorado. Currently multiple projects are being proposed along the Front Range of Colorado that would remove over 300,000 acre feet of new water from the Colorado River and its tributaries – all of this would be removed even before the river reaches Lakes Powell and Mead.

Additionally, climate change will likely have profound impacts on the Colorado River basin. Warmer weather, less snow, a reduction in stream runoff, and changed timing of spring runoff are all likely impacts. Climate Change is expected to reduce Colorado River flow by 10%-30% by 2050. Currently scheduled water deliveries from the Colorado system are not sustainable in the future if anthropogenic climate change reduces runoff even by as little as 10%. A recent federal study looking at water supply options for the Colorado River Basin recognizes that climate change is making status quo management regime of the river untenable, and underscored the need for optimizing existing water infrastructure, and increasing conservation and efficiency measures.

Stressed by a changing climate, impeded by six massive dams, diverted, stored, and desalinated to meet the requirements of water users, the Colorado now shows the strain of human overconsumption. While this outlook may seem less than bright, American Rivers and our partners are working to improve water management in the basin, promote water conservation and efficiency, and protect the river’s flows to ensure a healthy sustainable river for the benefit of people reliant on the river as well as the resiliency of the Colorado Basin ecosystem.