Flood Risk Assessment
Whenever new buildings or home are put forward for construction the local planning authority have to do a flood risk assessment by law (according to PPG25 - Planning Policy Guidance Note 25). This assessment is necessary to assess how likely it is for the area to be flooded or to have flooding related problems. It may also involve the Environment Agency as necessary.
In recent years the UK has experienced a lot more flooding of a higher intensity than in the past due, as many people believe, to the eradication of flood plains due to an increase in building. Flooding can be harmful to properties and can be dangerous for the people living in a flooded area so it is important for planning departments to try to avoid problems wherever possible.
There are various ways that floods are assessed. A planning authority, for example, will look at potential sources of floods and any historical incidences of flooding or related problems in the area. They may also undertake a process known as river modelling if the land in question is close to a river or water source. They key thing here is to work out how building on a site may also cause flooding if it takes away flood plain land or alters natural and man made drainage systems.