China backs dam plans

were " enduring one form or another of water scarcity ". In spite of water manufacturing capacity doubling between now and 2016, up to half the world's population will still be suffering shortage by the middle of the century, according to the GWI. The cost of desalination is falling as a result of technological development, increasing the demand, and the cost of reusing water from sewage can be cheaper still. New plants in Algeria are expected to deliver water for around 55 cents per cubic metre, and reuse from sewage can cost as little as 40–45 cents per cubic metre, considerably less than the cost of drinking water in the UK, but this includes piping it to taps, the GWI estimate. One of the ongoing concerns about desalination, however, is the energy cost but plants are increasingly looking to renewable energy sources. Plants that do not use fossil fuels are being developed in the UAE, the UK and other countries, like Australia. Europe's largest desalination plant on the River Thames in London uses biodiesel. Despite all these apparently sustainable water manufacturing developments, the Worldwide Fund for Nature remains concerned about building plants in often environmentally sensitive coastal and wetland areas and about the intake of seawater and discharge of the remaining concentrated brine, which can be contaminated with cleaning chemicals. " Desalination is, at best, a short-term solution. " And desalination can be of little help for some developing countries where growing demand for water occurs a long way from coastal or brackish supplies. Kenya's booming vegetable and flower growing businesses are centred inland and dependent on the river systems feeding Lake Naivasha. Environmentalists have raised concerns about the amount of water now being extracted, highlighting the fragility of supply in many regions. One of the most dramatic examples of overexploitation is that of the Aral Sea, between Kazakhstan and Uzbekistan, once the fourth largest inland sea. But years of extraction to irrigate crops in arid surrounding lands have seen it reduced to two remnants, less than 30 per cent of its former size. While World Bank funds are now helping to reclaim the northern remnant, the sea is unlikely ever to achieve its former size. And many more efforts are likely to be needed to protect environmentally important areas, while seeking to meet the inexorable rise in water demands around the world that water manufacture alone may not be …