Megacities, Development and Water

The world's population growth is dominated by urban growth, particularly in Asia and Africa. Urbanization is seen most dramatically as the growth of large urban agglomerations, which are mushrooming in all developing regions of the world. This demographic change is bigger than any other change that human history has recorded. Whereas in 1975, only 190 million people lived in cities with more than 5 million people, the figure had gone up to 394 million by the year 2000. The UN forecast tells that in 2015, over 600 million people are expected to have their home in a megacity. This paper summarises global demographic trends and prospects and relates them to the water sector challenges of large urban agglomerations in developing countries. Nine case cities are under particular focus. They are Dhaka, Jakarta, Bangkok, Riyadh, Singapore, Johannesburg, Istanbul, São Paulo and Mexico City. Whereas the approach and level of success is different in each case, no city can escape massive technical investment, institutional development and strong political will in managing their water and related environmental challenges in a sustainable way.