Southeast Asia, with most of its area receiving an annual rainfall of more than 2000 mm, is a region of positive water balance. It is also an area where unfulfilled demand for water is not unknown. Such a contradiction happens at times in its towns and cities. Several Malaysian urban settlements, for example, suffer occasionally from water shortage in a country with an average annual rainfall of about 3000 mm. Kuala Lumpur went through a prolonged period of water shortage in 1998 (Hamirdin 1998) in spite of large allocations made earlier in various five-year plans towards developing water supply infrastructure. Such shortages are common during long dry periods associated with El Niño. Regional water shortages may become more common in future, especially with the rising population and economic expansion. The shortages are the result of an inability to meet the rising demand of water in cities driven by both increasing population and progressive prosperity. Serious shortage occurs in large cities such as Jakarta, Bangkok, and Manila where a significant proportion of their population has no immediate access to municipal potable water. Even where piped connection exists, supplies are not available round the clock and often do not meet the required water quality standards. In many cities the local sources are inadequate and water has to be brought in from rural areas. The demand for water in a city has to be met on both quantitative and qualitative terms. For example, drinking water supplied to households by a municipal administration has to meet a given standard (WHO 1993). Ideally a city should have enough water to drink, to meet industrial demand, and to be able to store an adequate volume under pressure for firefighting and street cleansing. Supplying a city with water requires water sources, a treatment system, a distribution system, and arrangements for treating waste water and its disposal. In this chapter we review the current status of water supply in urban Southeast Asia and the sources that are available, concentrating on the major cities. We indicate the success stories as well as the shortcomings.
The current status of Zika virus in Southeast Asia
