Abstract: A modular component dam. The dam may be configured for pairing with another dam in the form of a closed loop pumped storage hydropower plant. One or both of the dams may be constructed of buttress frames made up of prefabricated modules of predetermined varying dimensions which allow for rapid construction over a period of less than about a year. The modules may be transported to dam sites by standard transportation units such as 18 wheelers. This is facilitated by the modules occupying no more than about 14 feet in vertical height above a surface of a roadway during transport and no more than about 11 feet in horizontal width across the roadway during transport.