Tamagawa

Overview

The Tamagawa is a first-class river flowing through Akita Prefecture, and it is the longest of all the tributaries of the Omono River. It also bears the alternate name Soikawa (or Soegawa). Because it gathers the strongly acidic water that pours from the Tamagawa Onsen upstream, its waters have long been known as Tamagawa dokusui, meaning the poison water of Tamagawa. Running roughly 103 kilometers, it nourishes the land of Akita and is deeply woven into local life and nature.

Highlights

• ●The longest of all the Omono River's tributaries
• ●The nickname poison water born of Tamagawa Onsen's acidity
• ●A historic river also called Soikawa
• ●A waterway of about 103 kilometers across inland Akita

History

The most distinctive feature of the Tamagawa is the powerfully acidic water that originates at Tamagawa Onsen upstream. Because this water affected agriculture and ecosystems, it long troubled people as poison water. Efforts to neutralize and manage this water quality intensified in the modern era, and the flood control and water improvement of the Tamagawa have been passed down as vital challenges of the basin. The river itself reflects a history of nature meeting human ingenuity.

Map

39.4850, 140.4417 · Wikidata

Suggested itinerary

1. 1Gaze at the current from a viewpoint along the Tamagawa
2. 2Reflect on the link between upstream Tamagawa Onsen and the water
3. 3Enjoy the riverside nature and scenery that shift with the seasons
4. 4Tour nearby sights and bridges after checking official information

Did you know?

💡 The pride of the Tamagawa is that it is the longest tributary of the Omono River. The upstream Tamagawa Onsen is famed as one of Japan's most strongly acidic hot springs, and because that water flows straight down the river, the distinctive name Tamagawa poison water was born. Knowing the story behind the name lets you sense the land's tale in every drop.

Nearby spots