oviding new infrastructure. Maintaining, renovating and enhancing existing water and wastewater infrastructure networks in areas that already have them: Sustaining and enhancing the capabilities of these systems to deliver better quality services and improved performance (enhanced quality of supply and wastewater treatment, more efficient and cost effective, higher environmental standards and stakeholder engagement, leading to sustainable systems). Globally, a number of factors have been responsible for changes in the approach adopted to the provision of water services in developed countries in particular and increasingly elsewhere: the recognition of concepts of sustainability and sustainable development, growing awareness of climate change, other socioeconomic pressures, changes in industrial bases and globalisation, and the development and availability of new technologies. Technological developments now make appropriate service provision feasible at reasonable cost, although there are needs for smarter and more robust approaches (WSSTP, 2005). For example, emerging and more efficient desalination processes using membrane bioreactors (MBRs) have been hailed by many as the future way of satisfying water demand. However, these processes use high amounts of energy and discharge concentrated brine effluents that can impact adversely on ecosystems (Harding, 2006). Currently there are more than 7 500 such plants worldwide, 60% of them in the Middle East. Energy needs to run a plant for a medium-sized city, such as Santa Barbara (United States) are some 50 million kWh/yr (California Coastal Commission, 2006) and unit costs are of the order of USD 1 per m³ of water produced (Twort, Ratnayaka and Brandt, 2000), which is up to ten times the cost from other sources. Recently plans for a new desalination plant in Sydney, Australia were shelved on environmental grounds following public opposition; similar objections were also cited for the rejection of a proposed plant in London. It is difficult for water utilities to gener