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
Japanese gunboat Sumida (1939) Japanese gunboat Sumida (1939) "Sumida" was the second of two vessels in the river gunboats authorized under the 3rd Naval Armaments Supplement Programme of 1937. "Sumida" had a hull with an overall length of and width of , with a normal displacement of 338 tons and draft of . She was propelled by two Kampon steam turbine engines with two boilers driving two shafts, producing and had a top speed of 17 knots. The ship was armed with one /28 cal. gun and one 25mm machine gun. " Sumida" was laid down on 13 April 1939 and launched 30 October