Part twenty-three

Sustainability Speak   

Water Resources

• The amount of water in the world is finite.
• World population is growing fast, and the use of water is growing even faster.
• A third of the world’s population lives in water-stressed countries now, and by 2025 this is expected to rise to two-thirds (with the world’s population predicted to reach 8.9 billion by 2050).
• The UN recommends that people need a minimum of 50 litres (11 gallons) of water per day for drinking, washing, cooking and sanitation.
• The ‘average European’ uses between 250 and 350 litres per day (55 and 79 gallons), and the ‘average American’ 600 litres per day (132 gallons). World Water Council.
• Theoretically, there is more than enough water available in total in the world to meet everyone’s basic (minimum) needs, provided it is used efficiently.
• Pollution seriously reduces the quantity of useable water available, and – through waterborne diseases – causes the deaths of more than 5 million people each year.
• 70% of the water used currently worldwide is used for agriculture (14% in the UK).
• Water is an essential resources for successful economic development to generate funds to tackle water problems in poor countries, and so it’s a vicious circle or an unsustainable situation.
• In reality, the UK has become the 6^th largest net importer of water in the world, with every consumer indirectly responsible for the use of 1000s of litres each day – so called ‘virtual water’ used in the production of imported food, textiles and other goods.
• Average household water use for washing, drinking and sanitation in the UK is approximately 150 litres (33 gallons) a person daily, but we consume about 30 times as much in ‘virtual water’ i.e. 4,645 litres (1022 gallons) a day per person.
• Only 38% of the UK’s total water use, including ‘virtual water’, comes from its own resources with the rest coming from the water system of other countries – some of which are already facing serious water shortages but have to keep exporting.
• The WWF has introduced the concept of the ‘water footprint’ and is working with some of the UK’s major companies (and particularly supermarkets) to encourage them to evaluate their ‘water footprints’ and to promote sustainable water use where water is scarce.
• In the UK we have, as part of our physical assets of water infrastructure, 1,000 reservoirs, over 2,500 water treatment works, 9,000 sewage treatment works and more than 700,000 kilometres of water mains and sewers.
• Direct leakage from the physical infrastructure is estimated to be 145 litres (32 gallons) per property per day, or 3,609 million litres per day (enough for 72 million people’s daily minimum needs, according to the UN).
• Through repairs and renewals, the UK’s 23 water companies are managing to reduce overall leakage by about 1%, or 40million litres (8.8 million gallons), each year.
• The UK’s water industry generated approximately 5 million tonnes of greenhouse gases through the supply and treatment parts of the ‘supply-use-treatment’ cycle, about 0.8% of the UK’s total greenhouse gas production in 2006/7.
• The use of domestic hot water generates some 35 million tonnes of greenhouse gases each year, i.e. approximately 7 times that for the overall ‘supply-use-treatment’ cycle.

One of the ‘Construction Commitments’ (Strategic Forum) is to reduce water usage in the manufacturing and construction phase by 20% compared to 2008 usage. (Strategy for Sustainable Construction).