Advances in decision support to aid participatory Colorado River Basin water management
The Colorado River Basin (CRB) is a vitally important resource for Western US water supply, agriculture, and hydropower. ÌýAlthough the 2007 Interim Guidelines (IG) set up a system of water shortages that were linked to reservoir storage elevations, the IG and subsequent drought management plans were not enough to protect system storage given continued drought. These regulations are set to expire in 2026, with a new management plan currently being negotiated. In support of this effort, the US Bureau of Reclamation has sponsored research on Decision Making Under Deep Uncertainty (DMDU) methods at the University of Colorado Boulder’s Center for Advanced Decision Support for Water and Environmental Systems (CADSWES). Outcomes of this research resulted in Reclamation creating a publicly available DMDU web tool (https://www.crbpost2026dmdu.org/), that allows anyone to create management plans (operating policies) and evaluate their performance under a wide array of possibilities of future water supply and demand for multiple system performance objectives. This presentation will discuss how research advances in DMDU methods have aided participatory decision support in the CRB. DMDU seeks to address challenges including conflicting goals of multiple stakeholders (preserving storage versus preventing shortages), divergent potential future conditions (a range of drier and wetter hydrologic inputs), and complicated relationships between decisions and outcomes. An initial research project demonstrated how simulation-based optimization using the Borg Multiobjective Evolutionary Algorithm (MOEA) and the CRSS model can discover promising management policies. A subsequent project created a framework to visually navigate tradeoffs among robustness metrics. Recent work has used the Self Organizing Map (SOM) to intelligently organize management policies and facilitate better understanding of the relationship between uncertain input scenarios and possible system performance outcomes. The ultimate goal of this work is to help Reclamation and Basin stakeholders navigate potential post-2026 management policies and maintain flexibility when future conditions become more severe than originally anticipated, as is currently happening in the CRB.