The built environment has grown rapidly over the last 50 years, resulting in large areas of land being paved over with impermeable materials. Over the same period of time the number of occasions that the UK experiences three, or more, consecutive days of heavy rainfall has increased by 50%.
With climate change predicted to lead to increasingly warmer and wetter weather conditions, rainfall is likely to continue to rise. As a result, many experts believe the kind of wide-scale flooding seen in 2007 and the winter of 2013/14 will become ever more frequent, unless dramatic action is taken now.