The water distribution system uses a precise geometric structure to ensure each village receives exactly one-third of the spring's volume.
The water temperature remains steady at 10 degrees Celsius throughout all four seasons.
The spring is designated as one of the '100 Famous Waters of Japan' by the Ministry of the Environment.
The name 'Sanbuichi' translates literally to 'one-third', referencing the specific historical water allocation method.
The current structure combines a functional historical landmark with a traditional Japanese restaurant.
The Sanbuichi Yusui Building is a restaurant and regional site centered around a historic water-splitting facility known as the Sanbuichi Yusui. The water originates from Mount Yatsugatake and is traditionally divided into three equal shares—hence the name 'Sanbuichi'—to irrigate the surrounding rice fields. The site features a wooden water-distribution apparatus designed by a local feudal lord during the Edo period to resolve water rights disputes among downstream villages. Visitors can view the clear, cold spring water flowing through the channel year-round at a constant temperature of 10 degrees Celsius. The building serves handmade soba noodles, utilizing the local spring water in the preparation of both the noodles and the broth. The facility provides views of the surrounding rural landscape and the Yatsugatake mountain range.
The wooden footbridge overlooking the point where the spring water splits into three distinct streams.
Sit at the tables near the window to view the water channel while dining.
Visit on a clear day to see the unobstructed views of the Yatsugatake mountains.
Try the cold soba noodles to best appreciate the quality of the spring water used in the process.
Do not attempt to touch or obstruct the water flow in the historic channel, as it remains an active irrigation site.
Closed on certain weekdays, typically mid-week; subject to seasonal adjustments.
Remove shoes when entering the tatami-style seating areas.
