Opening of modern waterworks

Fig. 2.1 Developments in Tokyo's water service, 1900-1995 (Source: Bureau of Waterworks, 1994)

Along with the opening of the country, the Japanese government imported advanced waterworks technologies developed in Western Europe. Beginning in 1887, modern waterworks were constructed under the supervision of William Palmer, an Englishman, in Yokohama, which had a large settlement of foreigners. The Yodobashi Purification Plant started operating in 1898. At the beginning, it was capable of supplying only 166,800 m³ of water per day to 80,000 people. However, as the population increased and the potable water service spread, the waterworks kept on growing. Private sector systems and nearby villages and towns were absorbed. Developments in Tokyo's water service are shown in figure 2.1; the growth in the average daily water supply is shown in figure 2.2.

These figures demonstrate the remarkable expansion of the water supply system. The process of expansion was not smooth, however. Some of the difficulties were the Kanto earthquake on 1 September 1923, World War II, and in particular the destruction of waterworks by air raids towards the end of the war, and then slow recovery. Furthermore, serious water shortages in the Tama River in 1940, flood damage in the eastern areas of Tokyo caused by Typhoon Katherine in 1947, and another serious water shortage caused by low precipitation on the Tama River Upper Basin in the summer of 1964 affected the management of the Tokyo water service.

The reconstruction of the water service facilities that had been completely destroyed by the earthquake of 1923 not only employed earthquake-resistant structures, but also involved the construction of new reserve water systems, changing from steam pumps to electric pumps at the Yodobashi Purification Plant, the carrying out of land readjustment for urban renewal, and major modifications to and expansion of water service networks. As a result of the unusual water shortages in the Tama River in 1940, water supply sources were reinforced, new wells were constructed, neighbouring water systems were connected, and emergency measures for water supply were completed.

Fig. 2.2 Growth in the average daily water supply volume, 1900-1995 (Source: Bureau of Waterworks, 1994)