Arakawa River (Kantō) Arakawa River (Kantō) The is a long river that flows through Saitama Prefecture and Tokyo. It originates on Mount Kobushi in Saitama Prefecture, and empties into Tokyo Bay. It has a total catchment area of . The river is one of Tokyo's major sources of tap water, and together with the Tone River, accounts for around 80% of Tokyo's water supply. Attempts to control flooding of the Arakawa River have been made since the area that is now Tokyo became the de facto capital of Japan during the Edo period. Following a major flood in 1910 that damaged a large
Arakawa River (Fukushima) The name Arakawa comes from the river long being known as an , meaning a river that floods often. Due these floodings, the Arakawa River has changed its course multiple times. The Ōmori River, now a tributary of the Arakawa River, currently flows in the former main riverbed of the Arakawa River. The Arakawa River's steep descent in the Tsuchiyu Onsen area formerly caused multiple earth and rock slides. To prevent further damage, in 1900 Fukushima Prefecture began flood control construction on the river, and in 1936 the country took over and began construction of the . The construction proved