The end of the big dam era is approaching. Numerous recently published reports reflect this planet-altering fact. One study, conducted by scholars at the United Nations University’s Institute for Water, Environment and Health, found that construction of large dams globally fell from a late-1970s peak of about 1,500 a year to around 50 a year in 2020. “There will not be another ‘dam revolution’ to match the scale of the high-intensity dam construction experienced in the early to middle 20th century,” the 2021 study concluded. Data compiled by the International Renewable Energy Agency (IRENA), an intergovernmental organization that promotes renewable energy, including hydropower, show that in the 21st century, newly installed hydropower capacity peaked in 2013 at 45,000 megawatts a year and then dropped every year but one through 2021, when it reached only 18,900 megawatts.