In Kuji, Kawasaki: a circular water diversion device known as 円筒分水 (entō bunsui) えんとうぶんすい . See: Splashing around Tokyo’s water infrastructure

See also: Ento bunsui 円筒分水: Shimokuzawa diversion pond

And also: Takatsu-ku ento-bunsui walking map (Kawasaki) 円筒分水と久地不動尊コース