 The new company, in part through foreign aid loans from the United Nations, began work on a new dam in 1952, based on plans which had begun as early as 1921.The main contractor for the project was Hazama Corporation, and construction was completed in 1956.Construction was facilitated by the steep V-shaped walls of the site, and its proximity to the Iida Line train (several stations of which had to be relocated once the reservoir began to fill.