 already happening, with industry in OECD countries such as Australia, Japan, the United States and Europe leading the way. However, this has been on the back of existing technology and systems configuration. For this approach to make any impact there has to be a step change in the intensity with which water can be reused. For that to happen, not only will new technologies that address problems of pollution and pollutant removal have to become widely available but physical infrastructure will also have to be adapted. While demand-side management offers the possibility of making a unit of water work harder, in a global context water for urban and rural domestic consumption as well as that for industry will constitute only some 40% of total demand. Agriculture represents the biggest potential area for improving resource availability, in terms of both quantity and quality. The greatest impact could be felt in the area of biotechnology - with the possibility of engineering more water-efficient cultures - and ICT, which would bring about more effective water use in agriculture. Improvement could also come from a greater acknowledgement of the need to better manage the role of "virtual water" (water used to produce products), with changing crop production (in developing countries) and import patterns (in developed countries) (New Scientist, 2006). (Global estimated use of virtual water is some .000 km³ per year.) It is also expected that new "water trading" initiatives will emerge, in which cities will be able to acquire agricultural allocations much more cheaply than new sources, expensive desalination or other systems (e.g. WSAA, 2005). Environmental pollution brought about by economic activity will continue to be a problem, more especially in the developing and rapidly industrialising/ 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 urbanising economies. It is unlikely, gi