Floods. The airport connection.

The flooding of the River Mole on the Surrey-Sussex border will no doubt cause a lot of inconvenience to a few people and give insurance companies something to think about but the media is assuring us that although the river runs in close proximity to Gatwick, the airport is not threatened at the moment. No mention however of the fact that the airport itself is a major contributing factor to the floods. Nothing aggravates flood conditions like urban runoff and airports with their acres of tarmac act as  huge rain catchments that run off into the nearest watercourses. If the streams and rivers can't handle the volume of water they burst their banks; sometimes with devastating results. The Mole runs through an area of comparatively low population density unlike West London's River Crane that is influenced by the runoff from Heathrow. Something that we don't hear much about when a third runway is being discussed.