The extended drought in the Colorado River Basin and growing demands of water supply have resulted in a declining reservoir system. This has highlighted the importance of planning for a drier future with the help of objective scientific knowledge and modern technology.

Building from our long-standing partnership with Arizona State University’s (ASU) Center for Hydrologic Innovations), ASU applied for and received a three-year, $1 million grant from NASA’s Earth Science Division in 2022 to identify short-term hydrologic indicators and improve CAP’s long-range scenario planning capabilities to inform decision-making for the Colorado River.

As part of this research, ASU uses cutting-edge data from NASA’s Earth-observing satellites. They combine this with predictions about future climate and land-use changes to project how much water will be available. ASU conducts regional hydrologic simulations in the Colorado River system using a computer model called the Variable Infiltration Capacity (VIC) model. ASU has improved the model to include better ways to account for snow-rainfall partitioning and model calibration. This detailed modeling, combined with satellite data, allows researchers to monitor and track changes in the Colorado River at various scales, from individual counties to the entire river system.

The ASU team works closely with CAP staff members to ensure the satellite data and modeling system are directly useful to plan, adapt and reduce the impact of this unprecedented drought. CAP staff members also help identify relevant project efforts.

Current research priorities include:

• Impact of deep soil moisture: Evaluating how deep soil moisture impacts how efficiently water flows into streams (streamflow efficiency)
• Evaluating climate forecasts: Comparing seasonal climate predictions to the index sequential method
• Developing new climate change projections: Incorporating climate change projections from CMIP5 and CMIP6 into VIC
• Supporting policy decisions: Using additional CRSS modeling at ASU to explore policy options for the Colorado River

Data from these research efforts is being used to analyze how streamflow efficiency in the Upper Colorado River Basin is impacted by spring temperatures, spring precipitation and deep soil moisture.

In collaboration with CAP, ASU disseminates project progress and results with a wide range of basin stakeholders, through the Colorado River Basin Climate and Hydrology Work Group, to ensure the research is relevant and widely understood.