It was useful to read your article on the needs in certain countries for improved engineering works to conserve water (NCE last week). As a tropical agriculturist, I felt however insufficient emphasis was given to the growing efficiency in the demand side of the water equation.
Israel's farmers get some 60% of their water needs from the recycling of wastewater. There is also significant use of 'grey water' systems for urban and industrial uses, together with aquifer recharge.
By balancing both supply and demand, stabilising river basin management and user volumes will curb the rather emotive talk of water wars. Effective legislation, practical teaching at all user levels and high class engineering will all play a part in reducing this growing source of political tension in arid lands.
Richard I Smith Summersbury, Chichester Road, Midhurst, West Sussex, GU29 9PS