Ellsworth Power House and Dam

The Ellsworth Power House and Dam is a hydroelectric power generation facility on the Union River in Ellsworth, Maine. The dam, located just north of downtown Ellsworth, is also known as the Union River Dam, and impounds the river to create Leonard Lake, named for project's engineer, James Leonard. The powerhouse is a Renaissance Revival building located at the western end of the dam. The power plant, built in 1907, was one of the first peaking power plants built in the state, and the hollow concrete dam is one of the highest hollow (or Ambursen-type) buttress dams ever built, having been described as "the highest power dam in New England" in 1928. The facility was nominated for the National Register of Historic Places in 1985, where it is currently listed.

Dam data from Wikidata (CC0) plus curated additions. Summary from Wikipedia (CC BY-SA).