. Advancing the use of drought early warning systems in the Upper Colorado River Basin: A transdisciplinary project

Abstract
The largely rural Western Slope of Colorado encompasses much of the headwaters of the Colorado River, a critical regional water resource used to meet multiple demands across a landscape that is frequently subject to drought. Water managers and users in this region rely on snowpack as a form of seasonal water storage as well as an indicator of drought. Climate change projections indicate that the regional warming trend will continue, causing the snowpack to melt earlier and produce less runoff for the same precipitation input, and potentially reducing the utility of snowpack conditions as a drought indicator. We conducted a two-year project to explore two overarching questions: 1) Will the key snowpack-based indicators used by managers still be valid under a changing climate; and 2) How do water managers use drought “early warning” information currently, and what are the opportunities for further use of drought information? We will present some of the key results of this research including discoveries about the role of elevation in modulating the utility of snowpack in predicting seasonal streamflow, and insights on current information use and how smaller water systems of the Western Slope access new sources of information. This project was a successful collaboration between researchers and practitioners with diverse and complementary backgrounds (hydrology, climatology, social science, policy, civil engineering, and water resources management) and broad experience working on water and climate issues on the Western Slope.