In the face of predicted water shortages and their rather over-hyped corollary–twenty-first century wars over water resources–the solutions of integrated management sometimes seem outweighed by the size of the difficulties to be overcome, if only because of the problems of putting into practice solutions which must be agreed between a number of countries with varied interests. Managing the needs of several countries, and often of several competing sectors in each one, on the scale of a catchment area, is no small undertaking, especially if there is a history of mistrust between the different governments. Modern civil engineering techniques prompt a fresh look at the possibility of diverting very large volumes of water originating far from centres of consumption over great distances.