Global urbanization and urban water: Can sustainability be afforded?

Urbanization is definitely one of the most characteristic global changes of today and of the coming few decades. Whereas the world population grows with almost one billion per decade, around four fifths of this growth is in urban areas. The challenges due to the development of urban centers, especially great urban agglomerations in developing countries in a sustainable way are huge. Water is one of the key figures in this equation. It has many roles; this paper discusses sustainable urban water infrastructure. First, solutions and experiences from the industrialized countries are summarized, and possibilities and difficulties to adapt them to large urban areas of the Third World are discussed. A particular focus in the affordability issue is taken. Various development indicators and their applicability are discussed. A summary and discussion on technical, economical, financial, and institutional alternatives follows.