Harnessing the power of moving water to generate electricity, known as hydroelectric power or hydropower, is one of the oldest sources of energy. Hydropower was once one of the most popular sources of electricity in the United States. However, the popularity of hydropower has declined over time. For example, 40 percent of all electricity that was generated in the early twentieth century was generated by hydropower. In contrast, as of 2022, hydropower only accounted for about 7 percent of all...