The River Sources of Tadewara
What makes the Tadewara Marsh so special is that it lies at a high altitude. Tadewara sits on the Handa Plateau at over 1,000 m above sea level. It was formed by waters from the mountain springs of Mt. Mimata and Mt. Yubi.
The streams of the Kuju area, fed by heavy rainfall in the region, cross the Handa Plateau. Annual rainfall of around 3,000 mm falls on the forests and grasslands of the area, flowing into the streams which in turn feed larger rivers such as the Naruko River that originates in Bogatsuru, and the highly-acidic Shiramizu River, which has its source high on Mt. Io.
Mt. Io, the only active volcano in the Kuju Mountain Range, releases sulfur into the Shiramizu River. This causes high acidity along and the whitish tint that gives the river its name. Almost no living creatures can survive in the inhospitable environment of the Shiramizu River. However, because the water source for the Tadewara Marsh is spring water, the marshland itself is home to a small fish called the Upstream fat minnow.