'On every roof something is possible': how sponge cities could change the way we handle rain

Amsterdam is home to 45,000 sq metres of 'blue-green' roofs, which absorb rainwater and allow it to be used by building residents to water plants and flush toiletsYou might visit Amsterdam for its canals, and who could blame you, really. But the truly interesting waterways aren't under your feet - they're above your head.Beautiful green roofs have popped up all over the world: specially selected plants growing on structures designed to manage the extra weight of biomass. Amsterdam has taken that one step further with blue-green roofs, specially designed to capture rainwater. One project, the resilience network of smart, innovative, climate-adaptive rooftops (Resilio), has covered more than 9,000 sq metres (100,000 sq ft) of Amsterdam's roofs, including 8,000 sq metres on social housing complexes. Citywide, the blue-green roof coverage is even bigger, estimated at more than 45,000 sq metres. Continue reading...