The Imaichi Dam (今市ダム) is a concrete gravity dam on the Togawa River located 4 kilometres (2.5 mi) west of Nikkō in Tochigi Prefecture, Japan.

The power plant operates using the pumped storage hydroelectric method.

During periods of high electricity demand, water is sent from the upper Kuriyama Reservoir to the power plant which contains 3 x 350 megawatts (470,000 hp) Francis pump turbines.

Water discharged from the power plant then enters the Imaichi Reservoir.

When demand is low, the pump-generators reverse mode and pump water from the lower reservoir back up to the upper.