Kurokawa dam is the biggest power generation with pumped-up water place in the country where I call an official name "Okutataragi power plant" and have 6 generators in the mountains.
Power generation with pumped-up water is something to draw water in the upper part dam using electricity in the time when supply of electric power has night to spare relatively, drop much the water on the lower part dam the daytime using electricity and generate electricity, and it's connected with Tataragi dam in the base. (Than Kansai Electric Power HP, part excerpt)
The looks of the Phil Locke dam of the height 98m onto which you loaded a stone are highlights.