Modeled sand transport, sandbar volumes, and reservoir operations for the Colorado River in Grand Canyon in support of resource impact analysis for Post-2026 reservoir operational alternatives (ver. 2.0, July 2026)

These data were compiled in support of the Post-2026 Operational Guidelines and Strategies for Lake Powell and Lake Mead (Post-2026) Environmental Impact Statement (EIS). These data were compiled to predict the impact of different proposed alternatives for Glen Canyon Dam operations on sand resources, including sand mass balance, sandbar volume, and frequency/duration of controlled floods (High Flow Experiments, or HFEs). These data were created for operations at Glen Canyon Dam for January 2027 through December 2060. These data were created by the U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center using numerical modeling methods.