The Ashio Dam is located at the junction of the Matuki River, the Nitamoto River and KuzoRiver.
Before the dam was completed, during a period of heavy rain, much earth and sand flowed causing floods downstream if it continues raining like that. The dam was built in 1955. Since then, the dam has prevented many floods, giving relief to those who live in the area.
In 1996, "The Akagane Waterside Park" was built downstream of the dam, and the "Ashio Environmental Learning Center" was constructed. The park and this center are good places to learn about history and nature of Ashio.
