Arakawa, Tokyo Arakawa, Tokyo Arakawa has sister-city relationships with Donaustadt in Vienna, Austria, and with Corvallis, Oregon, U.S. Domestically, it has similar relationships with nine cities, towns and villages. As of May 1, 2015, the ward has an estimated population of 208,763, and a population density of about 20,550 persons per km². The total area is 10.16 km². Arakawa is in the northeastern part of Tokyo. The shape is long and narrow, stretching from west to east. The Sumida River forms the northern boundary. The ward is surrounded by five other special wards. To the north lies Adachi; to the west, Kita;
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