The Age of Aridification on the Mighty Colorado River

The Colorado River is in crisis. Warm temperatures this spring meant that most of this year’s snowpack did not turn into water for river. Over the past two decades, the Colorado River Basin has withstood some of the driest years ever recorded, record-setting heat, continued declines in river flows, and catastrophic fires. This is aridification. Aridification is the long-term impact of climate warming in the arid West. It’s different than drought, which is temporary. Aridification is here to stay.

Aridification means there will be less water in the Colorado River for people and for nature, including birds. Everyone and everything that uses water is going to have less of it. One study shows rising temperatures are projected to reduce the Colorado River water supply by 20% at mid-century (as compared to the 20^th century average) and 35% by the end of the century (Udall and Overpeck 2017).

Drastic changes are needed to match the scale and urgency of the water crisis in the Southwest. While the state and federal governments that share the Colorado River consider new shortage rules to protect the Colorado River’s reservoirs, it will also be important to help water users adapt to the diminished water supply. There’s an urgent need to consider investments in projects and practices that improve the resilience of the Colorado River Basin to aridification.

Audubon contributed to a new report outlining a variety of approaches to adaptation and resilience, including some already well understood as well as new ideas. There are no silver bullets in these solutions, but together, they comprise a broad portfolio that could help increase supplies and reduce demands while improving habitat, reducing risk of wildfire, and helping rural and urban economies. In addition to exploring each of these solutions in depth, the report discusses how to increase (or in some cases initiate) them, calling for both pilot projects and large-scale investments, supportive financing, and action-oriented research.

Climate change presents an unprecedented challenge to the Colorado River Basin, and while policymakers debate how to mitigate carbon in the atmosphere, this report shows us that here on the ground we can start working on solutions within our grasp.

Aridification of the Colorado River Basin is a sobering challenge, as are climate impacts throughout the continent. Audubon’s climate report, Survival by Degrees shows that 64 percent (389 out of 604) of North American bird species are at risk of extinction from climate change. The good news is that some of the strategies that can help mitigate the impacts of aridification in Colorado River Basin can also help birds. One example is “natural distributed storage,” which is another way to say restoration of wetlands and high elevation meadows. These habitats are crucial for birds in the arid West, and also function as a way to store water high in the watershed where it can supply downstream uses over time.

Another strategy is forest management and restoration. It should come as no surprise that western forests are one of the habitats with the most threatened bird species in warming scenarios. As temperatures increase, drought, extreme heat, and fire will become more intense, more widespread, and more devastating across the West. Large-scale investment in forest management and restoration has implications for water quality and watershed health that affect both birds and people.

Climate change—and the aridification of the Colorado River Basin—is occurring at a scale and pace that threatens the security of water supplies and demands broader intervention than traditional water conservation efforts. The people and birds who rely on the Colorado River Basin require it. To learn more about the Ten Strategies, visit: www.tenstrategies.net