Public Relation

Tokyo Water Attractive Spots

Water Conservation Forest

Water Conservation Forest

Tokyo’s water resource, the Tama River originates in Yamanashi Prefecture, crosses the city, and flows out to the Tokyo Bay.
Tokyo Waterworks Bureau has been managing the Water Conservation Forest that spreads across the upper basins of the Tama River since 1901 to secure a stable amount of river flow discharge from this Tama River, and to conserve the Ogouchi Reservoir (Lake Okutama).
The Water Conservation Forest extends across Okutama Town in Tokyo to Kosuge Village, Tabayama Village, and Koshu City in Yamanashi Prefecture. The area is approximately 24,000ha with approximately 30.9km east and west, and approximately 19.5km north and south. This is equivalent to about one tenth of the entire area of Tokyo, and it is the largest forest in the country owned by any water supply utility.
There are climbing courses where you can enjoy “Mizuhi”※1 the headwater of the Tama River, as well as hiking courses in the mountains of natural forests mainly composed of hardwood trees such as beech and oak. You can experience the nature of the lush green Water Conservation Forest hands-on.
Tokyo Waterworks Bureau has performed steady conservations such as thinning and pruning to move ahead with the plan to expand the multilayered forest, where multiple generations of planted trees can coexist. Also, the Bureau is taking measures to cultivate healthy lush green forest that can prevent sediment discharge and store abundance of water. We have purchased and appropriately managed the private owned forests abandoned by their owners because they are not able to be well-maintained.
※1 “Mizuhi” means “Deadend of a Creek”, and it is the spot where the first drop of the Tama seeps out. From here, the long journey of approximately 138km to Tokyo Bay begins.

Please check below for more information about the Conservation Activities at the Water Conservation Forest

General Information

Name Water Conservation Forest
Location Access
(Main Walking Spots)
Suigenchi Fureai No Michi
●Mizuhi Zone (Genryuno Michi)
Surrounding area of Kasatori-Yama, Koshu City, Yamanashi Prefecture
60 min taxi ride from JR Chuo Line Limited Express ,“Enzan Station”
Appox. 40km from Katsunuma Interchange
●Yanagisawa Toge (pass) Zone (Road of Buna)
Surrounding area of Yanagisawa Toge, Koshu City, Yamanashi Prefecture
40 min taxi ride from JR Chuo Line Limited Express,“Enzan Station”
Appox. 30km from Katsunuma Interchange