Effect of building development on the risk of flooding under extreme rainfall

There is clear evidence to show that climate change is happening. According to the UK Climate Projections (UKCP09) we can expect warmer and wetter winters, hotter and drier summers, rising sea levels and more extreme weather events. These extreme weather events in the UK are likely to increase with rising temperatures, causing among others heavier rainfall events with increased risk of flooding. Flooding is currently identified as one of the greatest threats to the UK posed by the climate change. In the UK there is a continuous need for new housing. The UK government has set a goal of 1,000,000 new homes by 2020 in order to cover the country’s housing needs. This study examines the effect of building development on the risk of flooding under extreme rainfall, for an area that has a very low chance of flooding. Two different scenarios of building development were modelled using XP SWMM software. Results show that building development increases the maximum water depth and that the new built houses will flood under extreme rainfall.