Urban Drainage & Flooding Brochure

The risk of flooding is defined as a function of both the probability of a flood happening and its impact. In urban areas, the impact can be very high because the areas affected are densely populated and contain vital infrastructure. The reason for increased flooding in urban areas is twofold. Firstly, increased urbanisation has resulted in developments encroaching on floodplains, obstructing floodways and the loss of natural flood storage. Secondly, increased urbanisation has resulted in increased impervious areas such as roads, roofs and paving which create more rainwater water run-off.