Retirement of US Fossil Fuel-Fired Power Plants Increases Water Availability

United States fossil fuel-fired power plants are aging, with over 70% of capacity expected to reach a typical fuel- and prime mover-specific lifespan by 2035. While the closure of fossil fuel-fired power plants will help advance decarbonization goals, the cessation of water use for fossil fuel-fired power plant cooling - the largest water use in the U.S. - will also impact the nation’s water resources. We assess when, where, and how much water will be made available upon the expected retirement of the nation’s nearly one thousand fossil fuel-fired power plants by combining a lifespan-based model of fossil fuel-fired generator retirements for the US fossil fuel-fired electricity generation fleet with a national-scale hydrologic model. We show that water withdrawals and consumption of fossil fuel-fired power generators will be significantly curtailed (85.2% and 68.2% reduction, respectively) by 2035 if these generators follow their typical retirement timeline. Most rivers with fossil fuel-fired power plants diverting or discharging water will have a net increase in annual streamflow, with the most pronounced increases occurring in the summer months. The retirement of these power generators can produce noticeable impacts on streamflow volumes up to hundreds of kilometers downstream. By the retirement of the last fossil fuel-fired power generator in 2066, 2.6 billion m3 of water that was once consumed by these power plants could be made available for other uses. Economic and regulatory headwinds centered on making electricity more affordable and less carbon intensive will have the incidental impact of making the electricity sector less water dependent, which will benefit other water users and the environment.