The city’s history of flooding is partly due to inadequate and ageing infrastructure and its low-lying geography. DAR ES SALAAM, Tanzania: People have been moving to Tanzania’s commercial hub in droves, drawn by its booming economy. But the rapidly expanding population has put the infrastructure of Dar es Salaam under strain, and it is now buckling under poor urban planning. Africa’s fastest-growing city was initially designed for just 300,000 people. By 2030, its population of 7 million is