The 21st century is called “the century of the environment.” It is also referred to as “the century of water.” Water is one of the few substances on this planet that cannot be replaced by another. We greatly benefit from water that comes in the form of rain as a natural resource. It is a grace we receive from Mother Nature, but it is a highly unpredictable one as its availability varies considerably from region to region, and precipitation fluctuates tremendously from season to season and year to year. Demands for water resources have grown steadily in tandem with social development, and ensuring stable supply of water is becoming fundamental national policies in many countries in the world. When it comes to achieving a balance between supply and demand of water, it is important to keep its demand at a low level by reducing wasteful water use and to increase its supply. Because of regional and seasonal limitations inherent in natural water resources, hitherto untapped sources such as rainwater and underground water, recycled drainage water, seawater, desalinated seawater have been put to practical use. In addition to development and popularization of water-saving apparatuses, water-saving activities on the part of users plays a crucial role in reducing the demand for water. The water-saving activities must ensure convenience and amenity as well as sanitation in keeping with the existing water supply, hot water supply and drainage systems.
6L toilet, a symbolic representative of modern water-saving apparatus, was created in America in an effort to reduce flushing water in toilet from 20 litters down to 1.6 gal. Prompted from the viewpoint of conservation of water resources and stipulated in Energy Policy Act (1992), this shift represented a turning point in the water-saving movement. It has become a worldwide standard since. In Japan we had traditionally pursued our efforts at water saving through improvement of sanitary fixtures and water-related home electric appliances. But the introduction of 6L toilet has accelerated the nation’s water saving momentum further, and toilets with even less water for flushing are now being developed and marketed.
On the other hand, in the field of architecture, we have concentrated our effort at reducing environmental burdens through reinforcement of energy saving. When we use water in buildings, CO2 is emitted as a result of energy consumption in various stages of water flow including purification, conveyance and treatment. Water saving can be an effective means to reduce CO2. As far as reduction of CO2 in homes is concerned, Japan falls behind other nations, but a simulation study postulated that it is possible to reduce the total CO2 emission in Japan down to 1 % of the 1990 level (equivalent to 25% of all CO2 emission from kitchen, bathroom and toilet) by 2020 if we control the emission through popularization of water-saving apparatuses. This study made various organizations both in public and private sectors aware of the importance of building a society based on the concept of water saving, and as a result various policy-making processes have started. In addition, these activity fit in well with the Green Building orientation.
Since the prediction and estimation techniques used in the study can be applied to the whole Asian region, feasibility studies into the use of carbon credits in water saving have started in line with Ministry of the Environment’s “Feasibility Study Programme on New Mechanism” (MOEJ/GEC) and CDM in 2011. We expect that proposing this scenario for creating society based on the concept of water saving become a common key theme for sustainable development of Asian countries.
It is imperative that we take to heart the significance implied by the promotion of water-saving buildings in Asian countries: CO2 reduction, potentials for preserving water resources; and that we share this theme with researchers, policy makers and all others who are involved in the fields of water, environment and construction in Asian countries to establish scenarios for reducing environmental burdens and making a powerful shift to society geared to water saving. In view of this, we founded “Asian Saving Water Council” as a consortium for research organizations in China, Korea, Taiwan, Hong Kong and Japan to provide them with a common ground.
With this objective in mind, the first meeting of “Asian Saving Water Council Symposium” will be held at Meiji University in Tokyo. Talks and presentations will focus on such topics as Japan’s water saving endeavour and policies surrounding water resources; scenarios for creating society based on the concept of water-saving; issues surrounding water use, current status of water-saving, and development of water-saving apparatuses in China, Korea, Taiwan, and Hong Kong. We would like to make the arguments surrounding these issues open to the public and contribute to the realization of society built on the water-saving concept in Asian countries.