Snow Metrics and Decision-Making in the Colorado River headwaters

The Colorado River supplies water to over 40 million people in seven U.S. states and Mexico, running through the arid southwest of North America (U.S. Bureau of Reclamation, 2025). 70- 90% of the river’s water originates as snowpack high in the Rocky Mountains (Sprenger et al., 2024). This snowpack-dominated hydrology subjects the Colorado River Basin to large seasonal and year-to-year fluctuations in streamflow as determined by seasonal snowfall (Christensen et al., 2004; Li et al., 2017). As a result, several metrics and strategies for measuring snowpack and streamflow are used to quantify the expected runoff on an annual basis, yet the use of this information varies widely based on location and decision maker need. The goal of this project was to explore which snow and streamflow-related datasets, metrics, and information data users employ in the decision-making processes within the state of Colorado’s Colorado River headwaters and its associated trans-basin diversion regions (the Upper South Platte, Arkansas, and Rio Grande Basins). This work aimed to explore gaps in relevant flow-related measurements and how data, information, use cases, and data needs could be better translated between data users and providers. This report summarizes information from 39 semi-structured expert-elicitation interviews with data users (municipalities, recreation, watershed planning, ecosystem services, engineering services, and dam operations) focused on how, when, and why different snow and streamflow-related datasets are useful for decision-making processes in the Upper Colorado River Basin.

Suggested citation:

Fant, D., Kinsman, C., Stein, R., Petach., T., Vano, J. (2026). Snow Metrics and Decision-Making in the Colorado River headwaters. Aspen Global Change Institute. https://doi.org/10.69925/RUZU7996