Fighting over water in Australia, and turning cities into sponges in China. Phil Mercer reports on growing tensions over water management in Australia, a country used to dealing with drought. And Ed Butler hears how engineers and architects are turning Chinese cities into water sponges to manage the big fluctuations between drought and flood. He speaks to Kongjian Yu, dean of the Graduate School of Landscape Architecture at Peking University, and Jack Qian, head of Chinese operations of McGregor Coxall, an Australian landscape architects. (Photo: A flood in Wuhan in the Hubei Province of China, Credit: Getty Images)