2 Overview of Hydropower Regulation
With very few exceptions, FERC regulates all operating non-federal dams that generate electrical energy anywhere in the U.S. Its jurisdiction extends to each dam that meets at least one of the following tests: (1) occupancy of federal public land, (2) regulation of a navigable stream, (3) use of surplus water or water power from a federal dam, or (4) if constructed after August 26, 1935, any effect on interstate commerce, including linkage of the project to the grid. This jurisdiction includes any dam that, in addition to electrical generation, also serves other functions, such as water supply or flood control.
 See 16 U.S.C. § 797.