The Holyoke Dam, also referred to as the Hadley Falls Dam, or Hadley Falls Station is a granite dam built in tandem with the Holyoke Canal System at Hadley Falls on the Connecticut River, between Holyoke and South Hadley, Massachusetts. The water differential created by the dam produced mechanical hydropower for industrial uses in Holyoke, and …The Holyoke Dam, also referred to as the Hadley Falls Dam, or Hadley Falls Station is a granite dam built in tandem with the Holyoke Canal System at Hadley Falls on the Connecticut River, between Holyoke and South Hadley, Massachusetts. The water differential created by the dam produced mechanical hydropower for industrial uses in Holyoke, and later hydroelectric power.