The ,
Geography
The source of the Tone River is at () () in the
Echigo Mountains, which straddle the border between
Gunma Prefecture and Niigata Prefectures in Jōshin'etsu Kōgen National Park.
The Tone gathers
Tributary and pours into the
Pacific Ocean at Cape Inubō, Choshi in
Chiba Prefecture.
Tributaries
Major tributaries of the Tone River include the
Agatsuma River,
Watarase River,
Kinu River,
Omoi River, and the . The
Edo River branches away from the river and flows into
Tokyo Bay.
History
The Tone River was once known for its uncontrollable nature, and its route changed whenever floods occurred. It is hard to trace its ancient route, but it originally flowed into
Tokyo Bay along the route of the present-day
Edo River, and tributaries like the
Watarase River and
Kinu River had independent river systems. For the sake of water transportation and flood control, extensive construction began in the 17th century during the Tokugawa shogunate, when the Kantō region became the political center of Japan.
The course of the river was significantly changed, and the present route of the river was determined during the
Meiji period,
with the assistance of Dutch civil engineer Anthonie Rouwenhorst Mulder.
Its vast watershed is thus largely artificial.
Two ships of the Imperial Japanese Navy were named after the river, one of World War I vintage and another from World War II, the lead ship of its class. A third modern JS Tone currently in service with the Japan Maritime Self-Defense Force is also named after the river.
Fukushima Daiichi nuclear disaster
As a result of the Fukushima Daiichi nuclear disaster radioactive cesium concentrations of 110 becquerels per kilogram were found in
Silver carp caught in the Tone River in April 2012. The river is from the Fukushima Daiichi Plant. Six fishery cooperatives and 10 towns along the river were asked to stop all shipments of fish caught in the Tone.
[JAIF (26 April 2012) Earthquake Report 412: Cesium contaminated fish found in Tone river ]
Use
The Tone River was an indispensable inland water link between the capitol at
Edo, and later Tokyo, to the Pacific Ocean. It carried not only local products like
soy sauce from Choshi, but also products from the Tōhoku region, in order to save time and to avoid risk in the open sea. With the advent of the
railway in the 19th century major shipping on the Tone quickly declined, and inland ports such as Noda, Sekiyado, now part of Noda, Nagareyama, and Sawara, now part of Katori diminished in importance.
Today the river has several
that supply water for more than 30 million inhabitants of metropolitan
Tokyo and large-scale industrial areas such as the Keiyō Industrial Zone.
Rafting and kayaking
The Minakami
onsen area in Gunma Prefecture is near the source for the Tone River and during the spring snow melt period, April–June, the river provides consistent grade 4 rapids (on the International Scale of River Difficulty) over a stretch. The river provides some of the best white water
rafting and
kayaking in Japan. The snow melt swells the river to grade 4 in spring; in the summer it is a gentle grade 2. The Momijikyo section has 7 grade 3-4 rapids for and is long in total.
[ Minakami Rafting]
Cycling
The Tone River is home to Japan's longest car free cycling path. At over 220km long the Tone River Cycling Road 利根川サイクリングロード starts in Shibukawa City, Gunma and runs all the way to Choshi City, Chiba. The total route is over 230km but the final 10km or so into Choshi is on a road. The remaining 220km is on detached cycling paths high up on the river bank with great views of mountains while in Gunma and large rice fields and agriculture as you approach the ocean.
==Image gallery==
External links
