Figure 4: Global irrigation efficiencies, c. 2000
The world is on track to reach the Millennium Development Goal (MDG) on access to safe drinking water, but not that of sanitation – 2.6 billion people still lack access to basic sanitation – and some progress has been made in meeting water efficiency goals. Despite the progress, there are concerns that the limit of sustainability of water resources, both surface- and ground-water, has already been reached or surpassed in many regions, that demand of water continues to increase and that water-related stress on both people and biodiversity is escalating rapidly. Global water withdrawals have tripled over the last 50 years; aquifers, watersheds and wetlands are increasingly at risk yet are often poorly monitored and managed. The rate at which global groundwater stocks are decreasing more than doubled between 1960 and 2000. Today, 80 per cent of the world’s population lives in areas with high levels of threat to water security, with the most severe threat category affecting 3.4 billion people, almost all in developing countries. By 2015, some 800 million people are expected still to lack access to an improved water supply, even though improving the drinking water supply and sanitation is still a cost-effective way of reducing water-related disease and death. In many countries, data collection, monitoring and assessment of hydrology, water availability and water quality, which are critical to integrated water resource management and sustainable development, are lacking and must be improved.