Chuo-ku Tourism Association correspondent blog

The current Sumida River is downstream of the first-class river Arakawa, and is divided into the Arakawa Floodway at Iwabuchi near Akabane and pours into Tokyo Bay.
However, the flow of the river before the Edo period was completely different from now. The Tone River, which now flows into the Pacific Ocean in Choshi, used to be a river that flows to Tokyo Bay. A part of the flow of the Tone River at that time is the water surface of the "Kosumida River" that currently remains at the border between Adachi-ku and Katsushika-ku.
Since Ieyasu Tokugawa entered Edo in 1590, large-scale river replacement work has been carried out. Due to the eastern transition of the Tone River, the separation of Arakawa and Tone Rivers, and the excavation of the straight waterway of the Ayase River, the "Kosumida River" is no longer the main channel.
　
Many of the waterways stretched around Chuo-ku were reclaimed by the reconstruction of the earthquake, the reconstruction of the war, the Tokyo Olympics, etc., but the water surface of the Ko Sumida River is still preserved as a valuable waterside space in the city. . It is located a few minutes' walk from Tokyo Metro Ayase Station. It is impossible to imagine from the current scenery that this was once a large river, but the thoughts and hardships of many engineers in the past who struggled to rule the river and create a city where people can live easily, I think it should be passed on to future generations.