Water, water everywhere, and not a drop to drink. With apologies to the English poet Samuel Taylor Coleridge, that was the warning facing politicians, scientists and campaigners as the World Water Forum opened on the shores of the Bosphorus in Istanbul. 120 nations are in Turkey to tackle what some say may provoke increasing conflict – water, and the growing needs of a booming worldwide population.Campaigners say governments must face up to the fact that with the global family expected to reach some nine billion by 2050, the need for clean water may become the prime source of international rivalry. In a supreme irony, Turkish police resorted to water cannon as passions boiled over outside the Forum. The United Nations says nearly half the world will be suffering acute water shortages within 20 years. Demonstrators accused the Istanbul meeting of being a platform for water privatisation, and said life is more important than profit.