States dependent on the Colorado River are underutilizing treated municipal wastewater, according to a report from UCLA and the Natural Resources Defense Council. The report reveals that only 26% of wastewater in seven states reliant on the overdrawn river is being reused. Researchers highlight the stark contrast with Nevada and Arizona, which recycle over half of their wastewater, while other states like California, Colorado, Utah, New Mexico, and Wyoming remain below 22%.
Author Noah Garrison of UCLA’s Institute of the Environment and Sustainability emphasized the need to enhance water recycling to ensure a “sustainable, resilient water supply for the Colorado Basin.” The report finds that increasing wastewater reuse to 40% could yield an additional 900,000 acre-feet of water annually, sufficient to support almost 2 million homes.
Analysis of 2022 data from wastewater treatment facilities indicated substantial disparities among the states. Nevada leads with 85% reuse, followed by Arizona’s 52%. California, despite its regulations and goals, recycles 22%, while Utah lags with less than 1%.
“This is a striking divide,” noted Mark Gold, director of Water Scarcity Solutions at the Natural Resources Defense Council. He remarked on the river’s over-allocation, pointing out the need for significant federal and state investments to support water recycling efforts.
A lack of consistent data on wastewater reuse poses a major hurdle, with researchers describing a “data desert” that complicates understanding recycling efforts. Garrison noted the absence of robust reporting systems, making the expansion of recycled water use challenging.
No national standards for wastewater reuse currently exist. The report advocates for federal and state action to enhance data collection and establish reuse ordinances. Recommendations include developing federal model state reuse ordinances and expanding funding through programs like the Bureau of Reclamation’s Alternative Water Source grants.
“Water reuse won’t solve the Colorado River crisis alone,” said Garrison, but it remains a scalable solution for the long-term water scarcity problem.
The report arrives as the U.S. Bureau of Reclamation negotiates new river operating guidelines for the period after 2026. Without decisive action on wastewater recycling, the report warns of continued uncertainty for the basin’s future.
Garrison expressed concern over states’ limited knowledge regarding wastewater use but also recognized the significant potential for securing a stable future water supply. The report “Can Water Reuse Save the Colorado?” is publicly accessible online.
