Water source of Yokohama City

There are five water sources in Yokohama: Doshi River, Sagamiko, Banyu River, Sakawa River, and Sagami River, a total of 1,955,700m3 a day.

Water source of Yokohama-shi (PDF: 1,327KB)

What is a corporate group?...
Some administrative unions established by four organizations: Kanagawa Prefecture, Yokohama City, Kawasaki City, and Yokosuka City for the purpose of avoiding duplicate investment in water supply facilities and efficiently arranging and managing facilities.

Abalone water intake

At the Aoyama Water Source Office (Abiko) water intake 1 km upstream of Aoyama Water Source Office (Aoyama, Tsukui-cho, Sagamihara City, Kanagawa Prefecture), water from the Doshi River is taken 172,800 m3 per day, via Aoyama Seiden Pond, and sent to Kawai Purification Plant.
To Michishi Village Office website (outside site)

Numamoto Dam

Sagami Dam

After being stored in Sagamiko and used for power generation, 394,000 m3 of water is taken at the Numamoto Dam downstream, and then sent to the Nishiya Water Purification Plant via Tsukui Watershed Pond, Sagamihara Sinkden Pond, and Kawai junction well.

Lake Tsukui and Shiroyama Dam

Samukawa Water Intake

The water stored in Lake Tsukui and the water from small and medium-sized rivers flowing into the Sagami River downstream are taken at the Samukawa Water Intake (7 km upstream from the mouth of the river) and sent to Kosuzume Purifiction Plant a daily amount of 284,700 m3 for Yokohama City.

Lake Tanzawa and Miho Dam

Iiizumi Water Intake

The water stored in Lake Tanzawa upstream of the Sakawa River is taken downstream by the Iiizumi water intake, and the Kanagawa Prefectural Wide Area Water Supply Corporation draws 1,564,300 m3 a day and sends it to each water purification plant in Kanagawa, Sagamihara and Nishi-Nagasawa. . The amount of water in Yokohama City is 605,200m3 per day.

Lake Miyagase and Miyagase Dam

Sagami Ozeki

With the completion of the Miyagase Dam upstream of Nakatsugawa, full-scale water receiving was started in 2001. The water stored in Lake Miyagase is taken by the Kanagawa Prefectural Wide Area Water Supply Corporation at Sagami Ozeki on the Sagami River and sent to Ayase Water Purification Plant.
The amount of water developed is 1,300,000 m3 per day, of which 499,000 m3 for Yokohama City.