John Timmer, writing for Ars Technica:
In the US, the loss of landscape and wildlife to hydropower has made the installation of major new dams very unlikely; in fact, the government is seriously considering removing a number of existing ones, and has recently dismantled some smaller ones. But two reports by the Department of the Interior suggest that this doesn’t mean the end of new hydropower in the states. The DOI has gone through its catalog and identified existing dams and canals that could be fitted with generators, and found the potential for up to 1.5 million megawatt-hours annually.