Public Relation

The Landmarks of Tokyo Waterworks

Water Conservation Forests

Water Conservation Forest

 The Tama River, Tokyo’s own water resource, originates in Yamanashi Prefecture, crosses the city, and flows out to Tokyo Bay.  We, TMBW have been managing the Water Conservation Forests that spread over the upper catchment area of Tama River since 1901 to secure a stable amount of river flow of this Tama River, and to conserve the Ogouchi Reservoir (Lake Okutama).
 The Forests extend across Okutama Town, Tokyo to Kosuge Village, Tabayama Village, and Koshu City in Yamanashi Prefecture. The area is approximately 23,000ha 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 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 Forests hands-on.
We have 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, we are taking measures to cultivate healthy lush green forests that can prevent sediment discharge and store abundance of water. We have been purchasing and appropriately managing the private owned forests abandoned by their owners.
1 “Mizuhi” means “Deadend of a Creek”, and it is the spot where the first drop of Tama River 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 Forests.

General Information

Name Water Conservation Forests
Location Access
(Main Walking Spots)
Suigenchi Fureai No Michi
●Mizuhi Zone (Headwater trail)
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 Pass Zone ( Beech Tree Trail)
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

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