WaterAid and waterAround the world, 663 million people face a daily struggle to access enough good quality water. Having no choice but to drink dirty water, and lacking enough for washing, cooking, cleaning and food production, they get sick and their education and livelihoods suffer. Two things are critical for water security: good quality, well managed water resources and effective water supply services. Water resources cannot be easily accessed without pumps, pipes, taps, tanks and skilled people to manage them as part of a service. Similarly, water supply services alone are of little use without water resources. If either is unavailable or unreliable, people will not be water secure. All of the fresh water resources we depend on come from the natural environment. Rain flows in rivers and is stored in lakes, the soil or vast underground layers of rock called aquifers. The quantity and quality of available water can vary over time because of changes in the natural environment or through the influence of human activity. Natural disasters also have an impact on the quantity and quality of available water as well as the continuity of services. A number of factors can combine to threaten water security: Natural climate variability Human induced climate change Population increases and migration Settlement of hazard-prone land Poor service provision Uncontrolled discharge of pollutants into water Exclusion because of caste, race, social status or political affiliation Many of these threats can be managed to ensure that their impact is minimal, but often the political will and institutional capacity does not exist to do so. As a result, hundreds of millions of people remain without access to this basic human right.