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
Yamanote and Shitamachi certain "conflation" of the two terms, and those born in Shitamachi are typically considered true Edokko, children of Edo. This conflation is evident in the Edo period habit of saying "I am going to Edo" to mean going from the area around Fukagawa in Kōtō ward to anywhere east of the Sumida river. While the Yamanote grew west on the Musashino Plateau, in time the Shitamachi expanded east beyond the Arakawa river, and now includes the Chūō, Kōtō(Fukagawa), Sumida, and Taitō wards, plus part of Chiyoda ward. The center of Ueno in Taitō lies at the heart of the old