Why concrete + rain = flash floods

Britain's front gardens are being paved for parking while back gardens become patios. But in Canada and the US, the Depave movement is tearing up hard surfacesIn towns and cities, flash floods are a growing problem. The concrete jungle can't soak up rainwater, so in heavy downpours it has nowhere to go except into drains, overloading them and setting off flash floods. A movement in Canada and the US called Depave is tearing up concrete and asphalt in local neighbourhoods and replacing it with gardens to soak up rainwater and help prevent flooding. And although Depave is largely unknown in Britain, there's a growing need for similar action here. Continue reading...