🗺️ Baiwan Water Dam Fishway Management Building白丸ダム　魚道管理棟

The "fishway" is a specially designed waterway for fish to prevent dams or weirs from blocking river water, which would make it impossible for fish to swim upstream. Fish species such as sweetfish (香魚), cherry salmon (櫻鱒), and rainbow trout (虹鱒) swim upstream to spawn, and they cannot pass through artificial barriers in rivers. Therefore, gently sloped small waterways are specially constructed to allow fish to reach upstream. The Shiramaru Dam fishway, located in Okutama, Tokyo, is the largest fishway in Japan. This waterway, which is approximately 330 meters long and has a height difference of 27 meters, is open for internal visits on weekends, national holidays, and during summer vacation. By walking along a giant spiral staircase from the ground to the underground, visitors can closely observe the fishway within the tunnel. Walking through the tunnel lined with inorganic cement, while listening to the roaring sound of the river, feels like transforming into an explorer. Finally, one can gaze from the top of the dam at the entrance of the fishway. It’s worth taking a closer look at this uniquely designed feature created with the intention of achieving coexistence with nature.

You can view Japan's largest fishway, designed to help fish swim upstream, up close. It is open for free visits on weekends, public holidays, and during the summer vacation period. Walk into the fishway through the giant spiral staircase that leads into the tunnel.