Using Forecast Informed Reservoir Operations To Optimize The Tradeoffs Between Water Supply and Flood Risk

As a part of the WaterSMART Basin Study Program, Precision Water Resources Engineering (PWRE) worked on the Truckee Basin Water Management Options Pilot Study to develop flexible reservoir flood control operational criteria without increasing downstream flood risk. The study evaluated Forecast Informed Reservoir Operations, flexible rule curves, and changes to downstream regulation goals. This study is in the process of being documented in a Viability Assessment document and will be provided to the United States Army Corps of Engineers (USACE) for a potential subsequent update to the Water Control Manual. To evaluate methodologies to implement Forecast Informed Reservoir operations, the team used a Multiple Objective Evolutionary Algorithm (MOEA) to optimize the parameterization of the computation of required flood space based on the California-Nevada River Forecast Center ensemble forecasts. The MOEA provided an efficient tool to identify trade-offs between various basin objectives including flood risk, water supply, and environmental concerns such as health of threatened and endangered species. Ultimately, the MOEA informed a proposed revision to the Water Control Manual criteria that is based on the latest available runoff forecasts, adaptable to the changes in downstream regulation and flood improvement projects, and flexible in operations for water supply during dry periods.