Okubo water purification plant is a prefectural water purification plant located in Sakura-ku, Saitama City, Saitama Prefecture, Japan. The drinking water is supplied to about 3.8 million people in 15 cities and 1 town in the southern and western regions of Saitama prefecture. The maximum daily water supply capacity is 1.3 million cubic meters. Water is supplied to Saitama, Kawagoe, Kawaguchi, Tokorozawa, Hanno, Sayama, Warabi, Toda, Iruma City, Asaka, Shiki, Wako, Niiza, Fujimino, Fujimino, Miyoshi.