Hennepin Island P-2056

The hydropower facility includes a transition wall extending from the Corps’ lock structure; a horseshoe dam, spillway and roll dam located across the river and several earthen and concrete dams at various locations to control water flows; a main powerhouse located on Hennepin Island; two underground transmission lines connected to the Main Street substation; and several abandoned hydropower structures that are still listed on the license. The powerhouse includes five turbines with a total capacity of 12.4 megawatts, which is enough to provide power to 10,800 households.

The original hydropower license was granted on September 6, 1951, to the St. Anthony Falls Water Power Company. The license was transferred shortly thereafter to Northern States Power Company. The original license included a 16-megawatt Lower Falls. In 1956, a 12.4-megawatt Upper Development hydropower facility at Upper St. Anthony Falls was added to the license. In 1987, the Lower Development hydropower plant failed and has since been removed from the license. The license was reissued on March 8, 2004, for a period of 30 years and only includes the 12.4-megawatt upper development.

In December 2003, FERC, the Advisory Council on Historic Preservation, and the Minnesota State Historic Preservation Officer signed a programmatic agreement for managing the historic properties affected by the hydropower license.

Source: USACE