Reducing the Water and Waste Footprints of Megacities

The United Nations estimates that the number of megacities with a population of more than 10 million will triple from 20 in 2003 to 61 in 2015. It is estimated that more than nine tenths of urban growth will occur in developing nations, with four fifths of urban growth occurring in Asia and Africa.

Mega-urban societies are constantly challenged by complex problems, leading to the emergence of new and multifaceted social, economic and political organizational forms. Even without the anticipated growth, cities are facing problems with the provision of essential services, such as accessible and affordable water supply and waste management, leading to risks of negative health and environmental outcomes. But while the water and waste footprints of cities are enormous, they also offer potential for providing resources through recycling.

How can the water footprint of cities be reduced through efficient water use, capture and use of urban run-off and the safe reuse of water in agriculture? What are the opportunities to recover scarce resources (for example, phosphorus) and reuse waste water?

Deficient service provision in developing and emerging countries has led to the development of vibrant informal economies around water provision and waste recycling. How can service structures be changed without negatively affecting people who are dependent on these markets for their livelihoods? Can informal providers be integrated into public service delivery? How can the governability of the informal sector be increased?

Financial constraints make emulation of Western models difficult and infrastructural solutions such as water-borne sanitation systems are questioned for their environmental and economic viability. What are feasible options for financing improvements in water and waste management? Can public-private partnerships contribute to a solution of waste and water problems? What is the role of international organizations in this context? Is linking emissions trading to financing improvements in water and waste management a promising approach?