trategic decisions made in the past. Hence these systems are "path dependent". Fundamental strategic choices have been made in the past without proper critical evaluation, but dictate paradigms of delivery for long periods (Juuti and Katko, 2005). Current approaches to water supply and sanitation, developed over the past 150 years, are time-consuming to install and expensive, and generate environmental problems such as traffic congestion, dirt and noise. But there is actually no need to rely entirely on these traditional solutions, due to the fact that scientific developments have paved the way for alternatives as effective, reliable and robust as the traditional solutions, but less costly and less time- consuming to install and operate (WSSTP, 2005). Technological change presents the opportunity to challenge some but not all of the ways in which water services are provided. The key question is the extent to which technology can bring about the closing of the water cycle such that the requirement for the input of new resources is minimised. It must do INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 © OECD 2006 5. THE IMPACTS OF CHANGE ON THE LONG-TERM FUTURE DEMAND FOR WATER SECTOR INFRASTRUCTURE SO in a way that is cost-effective, appropriate for those who must use it, and capable of widespread adoption. There will be technological requirements to enable localised cycles to be closed, and at the same time technological needs to manage the wider systems within which the localised systems are embedded. This may be supported by enhanced techniques for desalination in the near future, benefiting arid countries in particular. There will be increasing requirements for real-time monitoring and control at every point in the water cycle. For developing countries, small-scale decentralised systems need to be better developed; that will require a range of new technological innovations, including new ICT systems that can ensure the secure operation and continuous monitoring of the