Time Line

1590

Tokyo

Legend has it, flood control expert Ōkubo Tōgorō selects drinking water sources by order of shogun Tokugawa Ieyasu.

 Edo period (1603-1868) 

Water supply from natural watercourses

1653

Tokyo

Completion of the Hamura Shusuiseki dam.

1654

Tokyo

Tamagawa brothers build the Tamagawa Jōsui Aqueduct

1859

Yokohama

Opening of Yokohama Port

The population of the town, up until then a village of about 100 families, grew dramatically and ensuring safe drinking water became a major challenge.

 Meiji era (1868-1912) 

Japanese tradition meets the West

1868

Tokyo

With the Meiji Restoration, Edo is renamed Tokyo and the water supply becomes the responsibility of the city's prefecture.

1883

Kyoto

Completion of the topographical survey between the cities of Ōtsu and Kyoto.

An application to begin construction of the Lake Biwa Canal is submitted to the government.

1885

Yokohama

Appointment of British engineer Henry Spencer Palmer as consultant for the start of construction of Japan's first modern water supply system.

Kyoto

Construction begins on the Lake Biwa Canal.

1886

Tokyo

Great cholera epidemic 

The population criticizes the conditions of the water supply system, which had remained unchanged since the Edo period, pushing for the implementation of a modern supply.

1887

Yokohama

Inauguration of the country's modern water supply system, with flow from the Nogeyama Reservoir towards central Yokohama.

1888

Tokyo

The study of the project begins to improve the water supply system.

1889

Yokohama

The city of Yokohama is founded with the ratification of the municipal system.

Kyoto

The city of Kyoto is founded with the ratification of the municipal system.

Plan is developed for the water supply system of the city of Kyoto.

1890

Tokyo

Passage of the first Japanese law regarding water supply services (Suidou Jōrei).

Kyoto

The first stretch of the Lake Biwa Canal is completed.

1898

Tokyo

The Yodobashi Jōsuijō Water Treatment Plant opens and drinking water begins to be distributed.

1901

Tokyo

Forest management begins in water source regions.

1902

Kyoto

The city of Kyoto submits the project for the second stretch of the Lake Biwa Canal to the provincial government.

1908

Kyoto

Construction begins on the second stretch of the Lake Biwa Canal.

1909

Kyoto

Construction begins on the first Water Treatment Plant in Kyoto (Keage Jōsuijō).

 Taisho era (1912-1926) 

Urbanization and modern water supply systems

1912

Kyoto

Opening of the second stretch of the Lake Biwa Canal. 

Completion and start of operations of the Keage Jōsuijō Water Treatment Plant, a pioneer in Japan for adopting the rapid filtration method.

1923

Tokyo

The Great Kantō Earthquake

The water infrastructure suffers extensive damage.

Yokohama

The Great Kantō Earthquake causes catastrophic damage to the Nogeyama Jōsuijō Water Treatment Plant and other facilities in the region.

 Shōwa era (1926-1989) 

Post-disaster reconstruction and the modern water supply system

1957

Tokyo

Completion of the Ogouchi Dam

1964

Tokyo

The Great Tama River Drought: the loss of up to 50% in supply led this critical situation to become known as the “Tokyo Desert.”

The largest water crisis the metropolis ever faced was aggravated by intense demographic and industrial concentration during the era of rapid economic growth.

1965

Tokyo

Deactivation of the Yodobashi Jōsuijō Water Treatment Plant.

 Heisei era (1989-2019) 

The constant evolution of water supply in the contemporary era

1992

Tokyo

The Kanamachi Jōsuijō Water Treatment Plant is completed as the first advanced purification facility (phase 1). Afterwards, similar facilities were progressively implemented at all Tone-gawa River treatment plants.

1996

Kyoto

Facilities related to the Lake Biwa Canal are designated as National Historic Landmarks.

2001

Tokyo

100-year anniversary of forest management in water source regions.

Yokohama

The Miyagase Dam begins operating at full capacity. 

The city now counts on a water infrastructure and springs that guarantee a stable supply for the city's future.

2003

Tokyo

The Tamagawa Jōsui Aqueduct is designated a National Historic Landmark.

2013

Tokyo

The advanced purification system is completely implemented throughout the Tone-gawa River hydrographic network.

2014

Yokohama

Renovation of the Kawai Jōsuijō Water Treatment Plant, the oldest still in operation in the city of Yokohama. 

It becomes the largest membrane filtration plant in the country that uses renewable energy.

2018

Kyoto

Navigation on the Lake Biwa Canal resumes.

Reiwa era (2019-) 

The quest for a future of sustainable water

2019

Tokyo

December 1 is declared Water Day in Tokyo.

2020

Kyoto

The Lake Biwa Canal is recognized as a Heritage Site in Japan.