The present condition of the water service in Japan

4.Present Status of Water Resources

The raw water of water supply in Japan is now abstracted about 70.9 per cent from rivers and dams (Fig.5).

Fig.5 Water Sources of Public Water Supplies and Bulk Water Supplies(as of March,2002)

Fig.6 Composition of Water Sources Excluding Bulk Water Supplies by Size of Water Supply(as of March,2002)

It is necessary to secure a large amount of raw water for water supplies in large cities, so they depend on river and impounding reservoirs to meet almost entire portion of their demand. As a result, the total volume of the use of impounding reservoirs as a water resources in FY 2001 was brought up to some 40.6 per cent, an increase of 12 per cent compared with FY 1965 (Fig.6). The ratio of reliance on impounding reservoirs is increasing year by year.