Collaborative Research: CAS-Climate: Reservoir dead pool in the western United States: probability and consequences of a novel extreme event

In 2021, 645 MW of power from Oroville Dam (California) were unavailable to the electric grid for five months due to drought conditions that resulted in “dead pool”—the condition at which reservoir elevations are too low to produce power. Projections of dead pool at Glen Canyon Dam (Colorado) in 2022 prompted major water resources operational changes to avoid this event. Yet there is currently no answer for the question: In a warming climate, what is the probability that large quantities of power production capacity in the western U.S. will go offline due to dead pool? The answer to this question has fundamental consequences for a decarbonizing grid, as hydropower is a low-emissions, dispatchable energy source whose operational flexibility facilitates the use of variable renewable energy, such as wind and solar. This project will evaluate the probability of synchronous dead pool conditions across multiple reservoirs in the western U.S. and produce estimates of the power capacity reduction, duration, and frequency of dead pool events. The project will evaluate the impacts of such events on reliability failures, electricity costs and air pollution emissions. The project will investigate how dam operators respond to dead pool risk, and evaluate the impacts of these adaptations. Policy-relevant research results will be disseminated through peer-reviewed journal publications, iterative feedback with dam operators, and ongoing collaboration with a stakeholder advisory committee to engage water and energy managers and policy-makers. The proposed research will specifically evaluate: (1) the probability of widespread dead pool events in future climates, (2) the consequences of these events for decarbonizing electric grids, and (3) the potential for reservoir management modifications to reduce the frequency of dead pool events. These research products will be coupled with ongoing collaboration with dam operators and energy-water system stakeholders to co-produce scientific results and enhance their utilization by water and energy managers. To achieve these research objectives, the project will apply a process-based modeling toolchain that incorporates extant downscaled climate data from the sixth coupled model intercomparison (CMIP6), land surface hydrology, and river routing and data-driven reservoir management with electric grid models that simulate capacity expansion and hourly production, along with qualitative interviews with dam operators to allow simulation of management adaptations. This project is co-funded by the Hydrologic Sciences, Environmental Sustainability, and Human-Environmental & Geographical Sciences programs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.