Although China has a large water resource in absolute terms, it’s availability is low on a per capita basis and unevenly distributed both geographically and seasonally. Overall China has about one quarter of the world’s average water per capita, but this falls to one tenth in northern and western areas. In almost all areas of China, water courses, lakes and groundwater are severely polluted due to agricultural pollution, and industrial and household discharges. Severe over utilisation and pollution have resulted in scarcity, inequitable distribution and degradation of aquatic ecosystems that have constrained economic development in addition to posing a major threat to the health and livelihoods of the population. In using 70% of abstracted water and returning less than a third of this water to watercourses, agriculture places by far the greatest stress on water resources.