The existing dam is the second structure to be called the American Falls Dam. Core samples taken in the early 1960s of the concrete of the original structure revealed deterioration resulting in impaired durability and strength caused by a chemical reaction between components of the concrete. The solution was to replace the original dam with a second dam built downstream in 1978. Replacement of the original dam was authorized by a congressional act of December 28, 1973 (87 Stat. 904, Public Law 93-206). In 1976, the Idaho Power Company built the dam's current power plant which consists of three generators with a capacity to produce 112,420 kilowatts (112 MW) of hydroelectricity.