For the past five years, water has been seeping out of the ground beneath parts of Nouakchott, undermining foundations and transforming some areas of the Mauritanian capital into uninhabitable marshes. Recent studies by the government suggest that nearly 80 per cent of the overall surface area of Nouakchott could be submerged in less than a decade - in 20 years at most. One scenario predicts the disappearance of the city by around 2050.