The bank estimated that per capita water availability in the region would fall by at least 50 per cent by 2050 and warned of serious social and economic consequences if countries failed to adapt their current water management practices, according to a report released in Cairo.
"We need to redouble our efforts to make sure that enough water of good quality is available to all of society now and will be available to our children and grandchildren," said the World Bank's vice-president, Daniela Gressani.
The region, which is 85 per cent desert, is one of the most arid on earth. It contains five per cent of the world's population, but only one per cent of the world's water.
According to the report, inefficient water management costs economies in the region approximately 1 to 3 per cent of gross domestic product every year.
Julie Bucknall, a leading natural resources specialist for the World Bank, said governments in the region actually spent a considerable amount of money on the water sector, but not in the most efficient manner.