Household demand, particularly in urban areas, is rising rapidly, particularly among wealthy consumers, in developed and developing countries, with an abundance of household appliances and garden irrigation.
In the Delaware River basin, the competing demands of water supply for New York City and the maintenance of the salt water front position below water intakes in Philadelphia would be negatively affected by future global warming, although the former would be more affected by climatic changes than the latter. However, studies suggest that climate variability would exert greater effects than long term climate change and that adjustment in the water control policy could offset some of the problems expected.
Many cities are facing serious shortages of safe water as a result of over-exploitation of resources and pollution. Bangkok's water table, for example, has fallen 25 metres since the late 1950s and saltwater has penetrated its wells (WWF 1990). Daily demand for water in Beijing increased almost 100 times between 1950 and 1980 (WRI, UNEP and UNDP 1992). Urban demand for water in Latin America is likely to rise fivefold during the next four decades (WRI, UNEP and UNDP 1994).