Hiyoshi Dam

In short

A multipurpose dam constructed on the Katsura River, part of the Yodo River system, in Hiyoshi-cho, Nantan City. It is a concrete gravity dam standing 67.4 meters high and spanning 438 meters in length; it took 37 years from the initial plan to completion, with management commencing in April 1998. It reduced flood damage downstream and made it possible to supply tap water for approximately one million people across Kyoto, Osaka, and Hyogo Prefectures.

• ​Info Gallery Walking Inside the Dam​​: Allowing visitors to tour inside the main dam body was the first such initiative in Japan. The dam's construction process is introduced through dioramas and actual materials, and at the innermost section, visitors can see the large floodgates used to release water during floods
• ​Lake Amawaka​​: The dam's reservoir covers an area about 70 times the size of Koshien Stadium. Its total storage capacity is the largest in Kyoto Prefecture, and it has been selected among Japan's Top 100 Dam Lakes
• ​Disaster Prevention Center (Visitor Center)​​: A facility where visitors can learn about the roles, functions, and dangers of water, featuring panels, videos, and scale models explaining Hiyoshi Dam

History and Highlights

​Hiyoshi Dam​ is a multipurpose dam constructed on the Katsura River, part of the Yodo River system, located in Hiyoshi-cho, Nantan City, Kyoto Prefecture. It is situated roughly in the middle section of the Katsura River, 55 kilometers upstream from the point where it merges with the Uji River and the Kizu River. It is a concrete gravity dam that supports water with the weight of the dam body itself, standing 67.4 meters high and spanning 438 meters in length.

The midstream area of the Katsura River features the narrow Hozukyo Gorge, and the upstream Kameoka Basin had repeatedly suffered inundation damage whenever floods occurred. Hiyoshi Dam was built to reduce flood damage downstream, maintain river water levels, and supply tap water for approximately one million people across Kyoto, Osaka, and Hyogo Prefectures. The project plan was first announced in 1961, when it was initially called Miyamura Dam. Built with the cooperation of the 201 households who relocated from the planned reservoir area, it took 37 years from the initial plan to completion, with management commencing in April 1998. In 1999, it received the Architectural Institute of Japan Prize.

The dam's reservoir, Lake Amawaka, covers an area about 70 times the size of Koshien Stadium and can store 66 million cubic meters of water. Its total storage capacity is the largest in Kyoto Prefecture and the largest among all dams connected to the Yodo River. Lake Amawaka has been selected among Japan's Top 100 Dam Lakes.

Viewing and Experience Highlights

• ​Info Gallery Walking Inside the Dam​​: In 1993, Hiyoshi Dam was designated as the very first "dam open to the local community." Allowing visitors to tour inside the main dam body was the first such initiative in Japan. In the Info Gallery, the dam's construction process is introduced through dioramas and actual materials, while its functions are explained using videos and panels; at the innermost section, visitors can see the large floodgates used to release water during floods.
• ​Disaster Prevention Center (Visitor Center)​​: A facility where visitors can learn about the roles, functions, and dangers of water, featuring panels, videos, and scale models explaining Hiyoshi Dam.
• ​Scenery of the Dam Lake and Mountains​​: The combination of Lake Amawaka and the surrounding verdant mountains is introduced by Nantan City as a superb view. Lawn plazas and cherry blossom viewing areas are also laid out around the dam.

Tips for Exploring

From Michi-no-Eki Springs Hiyoshi located directly below the dam, there is a walking route that passes through the lawn plaza and circles the crest of the dam, and you can also take a dip in hot springs after your walk. The dam crest can also be reached using the elevator in the Info Gallery. For a stroll in the woods, visiting Fumin-no-Mori Hiyoshi together, where you can experience nature, is also recommended. When the river water is rising, please avoid approaching the river. By train, it takes about 30 minutes on foot from JR San'in Main Line Hiyoshi Station, and buses are also available from the station.