PPS 15 Planning and Flood Risk (Revised)·Page 51·A4
Non-Climate Change Factors Affecting Flood Risk
Urban expansion increases flood risk independent of climate change, as impermeable surfaces replacing natural ground increase surface run-off into watercourses during heavy rainfall.
Flood risk is also driven by non-climate change factors. In this context the ongoing expansion of urban areas will increase flood risk as the loss of natural permeable ground and its replacement with impermeable surfaces leads to faster surface run-off into watercourses in the event of heavy rainfall.
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