Flooding from surface water

In November 2010 a new Flood Map for Surface Water was made available to Lead Local Flood Authorities, Local Resilience Forums and Local Planning Authorities.

Why does flooding from surface water happen and who is responsible for managing it?

Flooding from surface water happens when the local drainage system cannot cope with the rainfall.  It is extremely difficult to predict precisely where surface water flooding will happen as it is dependant on ground levels, rainfall, and the local drainage network.

Historically the split in responsibilities between local authorities and water companies has meant that there has not been a common approach to the management of drainage systems in urban areas.  This has been addressed in the Flood & Water Management Act (2010)  which has given Lead Local Flood Authorities responsibility for the management of local flood risk, which includes surface runoff, groundwater and flooding from ordinary watercourses (smaller rivers and streams).

Under the Flood Risk Regulations (2009) Lead Local Flood Authorities are also responsible for assessing, mapping and planning for local flood risk.  Water companies and Lead Local Flood Authorities will need to work in partnership to manage surface water flooding.

The Environment Agency has a Strategic Overview role in England and a Strategic Oversight role in Wales for all types of flooding.  In fulfilling this role we are working with local authorities to help them develop the knowledge and  understanding of the areas at risk of flooding from surface water.

New data is available to our partners

A new Flood Map for Surface Water is now available to Lead Local Flood Authorities, Local Resilience Forums, Regional Resilience Teams and Local Planning Authorities to help them to manage risk, respond to emergencies and assess planning applications.

Since July 2009, the original Areas Susceptible to Surface Water Flooding maps have been available to Local Resilience Forums and Local Planning Authorities.  This map was a good starting point in understanding the broad areas where surface water flooding is likely to cause problems.

The new Flood Map for Surface Water is currently the primary national source of information on the risk of surface water flooding as it contains a more realistic representation of the conditions that lead to surface water flooding. However, the original Areas Susceptible to Surface Water Flooding map will still be more appropriate in a few places.  As both of the maps are indicative,  they should not be used as the sole evidence for assessing risk or for any specific planning decision without further supporting studies or evidence, for example historic surface water records.