Dissolved oxygen estimates were generated to help understand how different alternative management scenarios may affect the likelihood of low dissolved oxygen in Glen Canyon Dam releases. The study aimed to examine the effects of different management alternatives on late summer and early fall dissolved oxygen concentrations in Glen Canyon Dam releases. The estimates represent estimates of dissolved oxygen concentration in Glen Canyon Dam releases between August and October of a given year. These estimates were generated using data collected in Lake Powell reservoir as part of a long-term inter-agency water quality monitoring program conducted by the Bureau of Reclamation, the National Park Service, and the U.S. Geological Survey. Specifically, the dissolved oxygen concentration in dam releases was modeled based on alternative hydrologies associated with alternatives under both the Near-term Colorado River Operations Supplemental Environmental Impact Statement (Interim Guidelines sEIS) and the Glen Canyon Dam Long-Term Experimental and Management Plan Supplemental Environmental Impact Statement (LTEMP sEIS). These estimates can be used to examine how different proposed alternative management strategies may affect oxygen concentrations in Glen Canyon Dam releases.

These data were compiled for/to modeling efforts for U.S. Bureau of Reclamation National Environmental Policy Act (NEPA) analyses for the Colorado River in Grand Canyon, Arizona. Objective(s) of our study were to create revised monthly Lake Powell elevations and outflows from Bureau of Reclamation Colorado River Mid-term Modeling System (CRMMS) traces that incorporate the alternatives in the sEIS documents and indicate when potential actions may occur and how that changes water movement and storage. These data represent monthly hydrologies for Lake Powell: inflow, outflow, and elevation forecasts for 2024-2027, as well as volumes of water in outflows for different water mangement strategies in NEPA supplemental environmental impact statement (sEIS) documents from the U.S. Bureau of Reclamation (USBOR). These data were collected in 2023 and 2024. These data were collected from the USBOR CRMMS and used by U.S. Geological Survey-Southwest Biological Science Center-Grand Canyon Monitoring & Research Center modeling. These data can be used to evaluate different water management strategy potential impacts to storage in Lake Powell.

These data were compiled to evaluate impacts of different reservoir management scenarios on sand exposure for aeolian landscape and cultural site resources. Objective of our study was to predict areas of dry, bare Colorado River sand as a function of different management alternative scenarios. These data represent predictions of dry, bare sand for the reach of the Colorado River between Glen Canyon Dam and Bright Angel Creek in Grand Canyon National Park. These data were created during 2023 by the U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center. These data can be used to understand how the area of sand available for windblown transport might be impacted different reservoir management alternatives and scenarios considered in the Near-term Colorado River Operations Supplemental Environmental Impact Statement (Interim Guidelines sEIS) and the Glen Canyon Dam Long-Term Experimental and Management Plan Supplemental Environmental Impact Statement (LTEMP sEIS).