Water Levels at Lake Mead Trigger 2020 Water Reductions in Arizona, Nevada, and Mexico

Today, the Bureau of Reclamation (USBR), the United States agency tasked with managing Colorado River water, issued a study that sets its operational guidelines for 2020 and governs water releases. Given end-of-year projections for Lake Mead’s water level at (just) below 1090 feet above sea level, USBR will declare a Tier Zero shortage for 2020.

Tier Zero is a threshold, created under new rules from the Drought Contingency Plan (DCP) that mandates Arizona and Nevada modestly reduce the water they take from the Colorado River. Mexico will also reduce Colorado River water use, under similar provisions in Minute 323. This marks the first time a mandatory measure to reduce deliveries from Lake Mead is being implemented. The DCP’s unprecedented cutbacks protect all Colorado River water users from the risk of catastrophic water shortages that would be necessary if Lake Mead’s elevation plummets. Those severe shortages could damage urban and rural economies and harm hundreds of species of birds—some of them endangered—that rely on Colorado River habitats.

While the mandated cutbacks are a monumental change in Colorado River operations, it’s worth noting that for years, water users have been conserving water in volumes exceeding next year’s requirement. In 2018, the total volume of water saved by Arizona, Nevada, California, and Mexico was fifty percent more than what they must conserve next year.

This past winter saw record or near-record snowfall in much of the Colorado River basin. Colorado River reservoirs benefitted from a healthy spring runoff, which will increase the water stored in Lake Mead enough to ensure it is in Tier Zero. If Lake Mead had declined, a Tier 1 shortage would have been likely, requiring more aggressive cuts to water users.

One wet winter does not solve the Colorado River’s problems. System reservoirs are barely more than half full. There is a structural water deficit because the Colorado is over-allocated. Climate warming is projected to dry the basin, further reducing the water supply. Some 40 million people in urban and rural communities, and 400 species of birds, rely on this river—all are at risk if Colorado River management does not continue to adjust to meet their needs in the context of climate change impacts.

The rules that govern how much water Lower Colorado River users can take from Lake Mead, including the DCP, Minute 323, as well as shortage guidelines first adopted in 2007, are set to expire in 2026. Colorado River stakeholders, including the environmental community, now have some time to evaluate if these rules work, and how they may need to change in the future—especially as the West becomes increasingly arid.

Audubon helped with the adoption of Minute 323, and worked throughout the West to advocate for the DCP. In the coming months and years, we will continue our work to protect rivers, groundwater, and the West’s network of saline lakes—for the birds and the people that rely on healthy and sustainable water.

To learn more about what's next for Audubon’s Western Water team, visit: https://www.audubon.org/news/a-colorado-river-drought-contingency-plan-place-now-what.

Join Audubon in helping us make progress on the reliability of water supplies for communities and birds in places like the Lower Gila River in Arizona, where smart effluent management can be a boon for Western Yellow-billed Cuckoos and Southwestern Willow Flycatchers.