Surface water flooding happens when the ground, rivers and drains cannot absorb heavy rainfall.
Typically this type of flooding is localised and happens very quickly after the rain has fallen, making it difficult to give any flood warning. It is therefore important to identify areas where measures need to be taken to protect properties and critical infrastructure from surface water flooding.
Surface water flooding is a general term which is used to cover flooding from:
- Runoff of rainwater from impermeable surfaces, such as roofs, roads, driveways, patios and car parks
- Groundwater in areas where water has percolated into the soil on high ground and then emerges in lower areas
- Flooding from small streams, drainage ditches, drains or sewers
As Lead Local Flood Authority, Norfolk County Council is responsible for looking at the causes of surface water flooding and its consequences, in order to learn lessons and help predict potential future flooding and minimise its effects.
We do this through our Surface Water Management Plans (SWMP) which utilise historical flood records and detailed models of potential future floods.
SWMPs are used to help identify areas that are at risk from surface water flooding during heavy rainfall events; these areas will be prioritised for further detailed study and work.
This work can involve a number of solutions, ranging from engineering work to reduce the risk of flooding to advising residents and businesses how to protect their properties from flooding.
Currently we have produced a number of detailed SWMPs, which you can view by clicking the links below.