Hydropower generation in the U.S. West plunged to a 22-year low last year — dropping 11 percent from the year before, according to a new federal data analysis. The total amount produced in the region amounted to 141.5 million megawatt-hours, or about 60 percent of the country’s total hydroelectricity output in the 2022-23 “water year,” per the data published by the U.S. Energy Information Administration (EIA).