Ōi Dam

The Ōi Dam is a concrete gravity structure that holds back the Kiso River, creating a large reservoir behind it. The thick walls support the weight of water while the impoundment extends along the valley, providing storage for the region.

Construction of the dam began in the 1920s as Japan pursued hydroelectric power expansion. The project represented early 20th-century engineering advances that brought reliable energy to the region.

The dam shaped the Kiso River valley and became part of the Tokai region's recreational spaces for local visitors. The reservoir area draws people who walk around the shoreline and enjoy the wooded surroundings.

Visitors can walk around the dam area and explore the shoreline of the reservoir from various viewpoints. The site is accessible year-round, though spring and autumn offer the most comfortable conditions for walking.

The dam showcases engineering techniques from Japan's early hydroelectric era and incorporates design elements typical of the 1920s construction methods. The structure reflects the industrial experimentation and material innovations of that time.

Location: Gifu Prefecture

Inception: 1922

Height: 53.4 m

GPS coordinates: 35.48139,137.39639

Latest update: December 8, 2025 19:54