Despite the laudable aims and achievements of the Rio Declaration and subsequent developments, 10 years on there remain 5 main areas for concern with respect to the sustainable management of water resources:

1. International basins and aquifers
2. Controlling demand
3. Maintaining and improving water quality
4. Environmental impacts
5. Climate change

International basins and aquifers 
Very little progress has been made in solving or, indeed, laying the legislative foundations for sound management of international basins and aquifers. Like population control, this is clearly a ?political hot potato? that is continually skirted around. Certainly some progress has been made in individual cases, like the Mekong (1994), with UN help, the bilateral agreement between India and Bangladesh (1996), or the Southern African Development Community accord (1995). Yet there is continuing discord and unsustainable management in many parts of the Middle East and Africa, and there seems little hope of real progress without a sound legislative framework agreed at the UN and internationally enforceable.

Controlling demand
Controlling demand and limiting wastage are being taken increasingly seriously by most countries of the ‘North’, but still more could be done. There is still a predominant culture throughout the world which relies on engineering solutions to expand the resource to meet the demand. Whilst such solutions are frequently necessary, they should be considered more often in the context of increased efficiency – including more efficient irrigation methods, dry technologies, recycling, and metered tariffs – than is currently the case.

Maintaining and improving water quality
Many countries, especially in Europe and North America have adopted the Principles of Polluter Pays and Prevention, including groundwater protection zones and integrated surface and groundwater protection zones, some extending to complete river basins. The International Council for the Rhine is an excellent example of coordinated international effort to improve water quality. Nevertheless, many rivers even in the Developed Countries are still heavily polluted, especially from non-point sources, notably agriculture. Having tackled point discharges, non-point sources are now the essential – and the more difficult – focus of attention. The Developing Countries and many former communist countries have barely begun to tackle their legacy of pollution – which often extends to polluted floodplain sediments that continue to be re-entrained during flood flows ? and, particularly in the case of Southeast Asia, rising pollution from uncontrolled industries and booming urban population.

Environmental impacts
Despite active promotion of Integrated Water Resource Management by the UN, fragmented institutional responsibilities, piecemeal developments, and especially a lack of concern for environmental impact continue to be all too common. The route forward is slow, especially in countries where ?environmental protection? is seen as a luxury and of far lower priority than increasing the GDP. It is time for a concerted effort to build and encourage international agreements on environmental protection within the framework of water resource development similar to those proposed for climate change. Above all, there is a need to convince the nations that the husbandry of water and land need to be planned together: that (1) water should be managed in such a way as to minimize the interference with nature and to maximize the benefits for nature, and (2) the environment should be managed in such a way as to minimize adverse impacts on and maximize benefits for water resources or flood hazard.

Climate change
The impacts of climate change on water resources were hardly beginning to be addressed 10 years ago. The 1992 Framework Convention on Climate Change marked the beginning of a series of attempts to reach international agreement on atmospheric emissions, which have not been particularly successful in global terms. As for water resources, scientific research into the regional and global impact of global warming on hydrological regimes is still in its infancy. This is even more so for mitigation strategies designed to cope with a changing water environment. Yet the evidence for substantial impacts is far more established now, and both the science of hydrological impacts and the methods of mitigation must count as priorities for water resources management.