People use water in hugely varying quantities. China, India and the United States are the top three users of water – and they are also the countries with the greatest population sizes. In the UK the average person uses about 50 litres of water per day to flush a toilet (depending on type of toilet – some use 12 litres of water per flush compared to more modern ones using between 4-6 litres per flush) more than 10 times the total water available to people lacking access to improved water sources in much of rural Sub-Saharan Africa. In Phoenix Arizona, a desert city in the US, water usage is more than 1,000 litres per person per day – in Mozambique it is less than 10 litres. Even bottled water – the US consumes 25 billion litres of mineral water and the Italians and Germans between them consume enough mineral water to cover the basic needs of more than 3 million people in Burkina Faso for cooking, washing and other domestic purposes.

Contrast this with the 1.1 billion people in the world who live more than 1 kilometre away from their nearest water source and who use less than 5 litres of water a day – barely enough to survive. The World Health Organisation (WHO) and the UN estimate (for monitoring purposes) that an individual needs a basic survival minimum of between 2-4 litres per person per day of clean water just for drinking and for very basic personal hygiene – that’s less than one-tenth of the average daily amount used in rich countries to flush toilets. This individual minimum increases to an estimated basic minimum of 20-50 litres from an improved water source within a 1 kilometre of the household when considering the protection of community health – health and hygiene promotion (sanitation, bathing, laundry, etc). Imagine this minimum requirement in a densely populated squatter community with over 100,000 inhabitants? Many urban water supplies (where supplied) in low-income countries are unreliable, irregular and of poor quality. Many inhabitants are forced to buy water at inflated prices from street water vendors. Shared toilets and pit latrines are grossly inadequate in high density urban areas – often badly maintained and rarely (if ever) cleaned. Children and women find it difficult to use these public places and the costs to a poor family is often prohibitive. As a result, urban dwellers may be forced to resort to open defecation or defecating in a bag/wrapping, which is then dumped.

Source: DFID

The above table gives examples of water required per unit of major food products, including livestock, which consume the most water per unit. Cereals, oil crops and pulses, roots and tubers consume far less water.

Source: www.water.org/waterpartners.aspx?pgID=907