These include high recycling rate of water; 80 - 90%, in the industries consuming the greatest amounts; and the high level of seawater use; 20 - 25%.
It is desirable that such resource-saving experiences where be applied in measures as regards water resources in China, where industrialization has speeded up recently, the industrial share of water consumption in Asia exceeds that in Japan.
As has been observed, industrial water consumption has relatively low elasticity in relation to increases in industrial output, and composition of the water consumption by sector has gone through a stable transition in recent years in Japan. Special efforts have been made to achieve this favorable trend, which I wish to detail. As far as the Public water supply is concerned, the proportional cost of industrial water consumption per output is far below that of households' water consumption. This is true even in the industries which are great water users. In contrast with the much lower efficiency in agricultural water consumption, which depends on natural water flows, notable further measures have been taken with regard to industrial water consumption. Recycling rates of the latter in Japan have been rising consistently since 1975. The ratio to the whole industrial water consumption exceeded 70% in 1977, and reached 77% in 1995, albeit with some variations between individual manufacturing sectors. Thanks to such water-saving measures, the amount of supplemental fresh-water used has tended to decrease on a long-term basis since 1975.
The factors contributing to the increase in the recycling rate are said to be (1) Constraints from tighter regulation on use of groundwater, (2) Consideration of draught water flow, (3) Effluent regulation, and so on. It should be appreciated that all measures taken to deal with these conditions have been in accordance with the basic strategy of efficient use of water resource, and made use of features of industrial technology.
In developing countries, the concept of "unit requirement" of water has not prevailed due to the relatively low cost of water. Examples can be raised from those great water consumers, the pulp and paper industries in Japan and China.
