| Dōzan River 銅山川 |
|
|---|---|
| Origin | Mount Kanmuri |
| Mouth | Yoshino River |
| Basin countries | Japan |
| Length | 55 km (34 mi) |
| Source elevation | 1,732 m (5,682 ft) |
| Avg. discharge | 500 m3/s (18,000 cu ft/s) at mouth |
| Basin area | 280 km2 (110 sq mi) |
The Dōzan River (銅山川 Dōzan-gawa) is the largest branch of the Yoshino River and flows through Ehime and Tokushima prefectures in Japan. Its name was derived from the Besshi copper mine that is now closed. In Tokushima Prefecture, it is called the Iyo River (伊予川 Iyo-gawa).
The rivers originates Mount Kanmuri on the borders of Ehime and Kōchi prefectures. It then flows through Shikokuchūō in Ehime Prefecture and Miyoshi in Tokushima Prefecture, before joinging with the Yoshino River.
In 1900, poisons from the various minerals excavated at the nearby copper mine seeped into the river, poisoning the local populations downstream.