Aimata Dam

The Aimata Dam is a 67-meter concrete structure that spans the Akaya River and creates a lake at an elevation of 556 meters above sea level. The gravity dam uses its own weight to hold back water and powers two hydroelectric plants in the area.

Construction began after the devastating Typhoon Kathleen in 1947, and the structure was completed in 1959 after resolving bedrock leakage issues. This dam became part of broader efforts to protect the region from future floods and secure water supplies.

The creation of the dam led to the relocation and preservation of the Sarugakyou hot springs, which now operate as a resort area near the lake.

The location is set in the mountains and is best accessed during dry weather, with paths around the lake offering good views of the structure. Visitors should expect varying elevations and steep sections, especially if they want to explore how water flows from the lake.

The artificial lake formed by the dam was recognized in 2005 as one of Japan's Selected 100 Dam Lakes, drawing attention to this less visited corner of the region. This designation made the water body a notable destination for those seeking to combine engineering achievement with natural scenery.

Location: Minakami

Inception: 1959

Elevation above the sea: 556 m

Height: 67 m

Part of: 利根川上流ダム群

Website: https://ktr.mlit.go.jp/tonedamu/tonedamu_index001.html

GPS coordinates: 36.71250,138.89278

Latest update: December 9, 2025 18:43