◆Stone-Paved Mountain-side◆

  The summit of Hachibuse -yama is about 10 kilometers southwestward away from Mtsumoto Castle. Its altitude is 1929 meters. Utsukushigahara Highlands are rucshing up to it across a deep ravine carved by Susukigawa river.
  The waters from the west side of its long ridge-line running from south to north form Ushinusegawa river. It flows into urban area of Matsumotob City to get together to make Naraigawa. Thereafter it confluences with Saigawa.
  Ushinusegawa as a branch flows only for nine kilometers. But because of the landform and climate there, the river had flooded out to bring some heavy landslide, thus to ditroy fields and villages in downstream -areas. The sudden heavy rains had brought severe disasters. The mountain consists of fragile rocks and huge gaps called a belt of Gofukuji Faults runs along Ushibuse ravine.
  In the head- and upstream zone of Ushibusegawa they made stone pavement on every slope and streamside under altitude 1600 meters.

◆Stone Pavement on Slopes◆

  To avoid landslide by heavy rainfall, the all slopes is covered with stones on the mountain -side. But on most parts the stone-works are covered with soil.
  They paved stones on so steep slopes rhat it is very difficult to climeb and thereafter covered them with earth to plant trees and grass. Thus they reconstructed the ecology system as a whole.
  They accumulated earth to make thick soil on which many plants have grown. However under it huge lots of stones are paved. Deeply impressed to think how hard they worked on such steep slopes how they are intelligent.
  As there are slight gaps among stones, some deal of water penetrate into the eath. Waters on the stone pavement get together on hollows to form small-shallow streams. They often flows down as falls somewhere.

◆Streams and Landform◆

▲Stair-strems don't save water and let them fall along stone-works not to accumulate potential energy but to release it.

  However near the end of steep headstreams, flows get together to widen and deepen the stream. Inclination changes and also structure of the stream. It became a brooks, furthermore a river at the bottom of the ravine around Suginosawa dam.
  It flows down on the waterway guarded with stone-walled banks on its both sides by the cottage called Matsukengoya. And confluences with Dorosawa stream.

▲The waterway of middle inclination has the wider bottom and the higher banks to endure the flow velocity and depth.

  The landform of the ravine-bottom gets so gentle under the fourth dam that the stream flows calmly like a murmur brook. But before long it meets a steep landform again to change itself into a fall sustained by stone-walled dam.
  The stream form itself a gentle brook on the flat places. But on the steep slope between them it change into an artificial fall to lose its potentiial energy.