FERC issued a preliminary permit for a proposed 17.7-MW project on the Mississippi River in Missouri and Illinois. The project would use an existing Corps of Engineers dam.

From the order (docket P-12724):

The proposed project would use the existing U.S. Army Corps of Engineers' Mississippi Lock and Dam No. 21, and consist of:  (1) a proposed powerhouse containing 16 generating units with an installed capacity of 17.70 megawatts; (2) a proposed 12-mile-long, 69-kilovolt, or a proposed 1/4-mile-long, 34.5-kilovolt, or a proposed 3⁄4-mile-long, 138-kilovolt transmission line; and (3) appurtenant facilities.  The average annual generation is estimated to be 69,185 megawatt hours.