Over a billion people – almost a fifth of the world’s population – still do not have access to a safe and convenient source of water. All over the developing world, women and girls spend hours every day on the drudgery of hauling water for their families from distant sources. And in urban slums, many poor people are forced to pay exorbitant prices for water from vendors. Water from these sources is often contaminated, and rarely enough to meet the needs of households.

Poor quality water causes disease and death (see the Water Quality page) , but not enough water is even more dangerous. Without a sufficient quantity of water basic hygiene is impossible and the result is a host of hygiene-related diseases, notably diarrhoea and acute respiratory infection (ARI), the two greatest killers of children.

Studies show that when water sources are more than 30 minutes away from their homes, people – and especially children – are highly vulnerable to hygiene-related diseases. But many people live further away from their water: UNICEF surveys from sub-Saharan Africa, for example, show that over 40 percent of households are at least this far from the nearest water source. In some areas the situation is getting worse. Environmental degradation, over-pumping and now global warming is further diminishing already scarce freshwater resources.