hattoku bridge was constructed upstream. with improved techniques and equipment, fill for the dam was laid at a pace of per year, enabling the dam to be constructed in 26 months. sediment from the yokoyama dam's reservoir was used as fill as well. in september 2006 initial filling of the reservoir behind the tokuyama dam began and by june 2008, the dam was complete. filling was complete in september. in october of the same year, j-power passed oversight of the power station construction to chubu. the first generator, unit 1, was commissioned on 15 may 2014. unit 2 should be commissioned by june 2015.