Shane Coors, Katrina Grantz, Dan Bunk and Shana Tighi

Abstract: The Lower Colorado Region and the Upper Colorado Region of the Bureau of Reclamation in collaboration with Precision Water Resources Engineering and CADSWES have developed a RiverWare model of the Colorado River Basin called the “Mid-term Operations Model” (MTOM). The MTOM model is part of a system of components that are designed to process the Colorado Basin River Forecast Center’s (CBRFC) Ensemble Streamflow Prediction (ESP) forecast. The 28 sets of ESP forecasts are run through the MTOM model and the output is collected and analyzed statistically to provide estimates of uncertainty for critical basin conditions and thresholds, such as equalization between Lake Powell and Lake Mead, or the likelihood of shortage, etc. An overview of the methodology, system components, and the RiverWare model will be presented, as well as a sampling of initial results from the modeling system.