Official

Let's go up the Sumida River flowing through Chuo-ku upstream. At Shimo, Kita-ku, you will arrive at the point where Arakawa and Sumida River are separated. From here, Arakawa heads to the sea with a thick river width, but do you know that this Arakawa is an "artificial river"?
Before the Meiji era, Arakawa was flowing along the current flow path of the Sumida River. A record flood occurred in Meiji 43 (1910), causing severe damage to Tokyo. This triggered the excavation of the Arakawa Floodway, and was completed in 1930 (1930).
Iwabuchi sluice gate is set up in the Sumida River, which is divided from Arakawa. Reiwamoto (October 2019) In Typhoon No. 19, the Iwabuchi sluice gate was closed with the rise of the water level in Arakawa, protecting the Sumida River from the flood of Arakawa.
There are many kinds of bridges in the Sumida River. Why don't you take a walk from Chuo-ku to the beginning of the Sumida River while watching the bridge?
In addition, the Shingashi River flowing from Saitama flows into the Sumida River.
By the way, this spring, I spent two days walking along Arakawa from Iwabuchi Suimon to near the mouth of the river. It's sunburned!