Whereas in developing countries the proportion of the urban population with access to safe water supply rose from 67% in 1970 to 77% in 1975 and then declined slightly to 75% in 1980, although the proportion of rural people served by safe water supply increased from 14% in 1970 it had still reached only 29% in 1980. The waste water treatment situation was even less heartening. While a high proportion of the developed urban populations had adequate services, the proportion of developing country urban population served by sewers and other sanitary facilities declined during the decade, from 71% to 53%. In rural areas the numbers served were 11% in 1970 and little better (13%) in 1980.
The total water use in 1980 was in the order of 2,600 to 3,000 km3/year; this is projected to have reached 3,750 km3 in 1985 - about 8 to 10% of the average run-off in all continental river basins. The three major uses of water are: irrigation (73%), industry (21%) and domestic and recreational uses (6%). The 1970s saw further extension of irrigation (and improved drainage) to newly reclaimed lands, especially in arid regions. Industrial uses increased during the decade, but savings were also made through increased efficiency. In Japan, for example, total industrial withdrawals increased from about 50 million cubic metres in 1974, but by the mid-1970s two-thirds of this was recycled water compared with one-third in 1965. Total water demand for the year 2000 is predicted to be between two and four times that for 1970.