Based on national mapping provided by the Environment Agency, DEFRA identified that a significant number of properties in the Borough of Epsom & Ewell would be susceptible to surface water flooding. Subsequently we have prepared a Surface Water Management Plan (SWMP) for the Borough.
Surface water flooding can be caused by intense rainfall before it enters a watercourse or sewer, overland flow resulting from high groundwater levels, exceedance of the capacity of the sewer network and 'out of bank flow' from small watercourses which are not designated as an Environment Agency Main River. In addition to damage to properties, roads and other infrastructure, the onset of surface water flooding can be relatively sudden and can lead to both high velocity flows in steep areas and deep ponding of flood water.
The purpose of the SWMP is to identify sustainable responses to manage surface water flooding and to prepare an Action Plan. The Action Plan provides an evidence base upon which future decisions and funding applications for putting the recommendations into practice can be put forward. Preparation of the Action Plan has followed the latest DEFRA guidance.
The overall philosophy supported throughout the SWMP study is for incremental change which takes advantage of opportunities as they arise. These cumulatively have the effect of better managing flood risk. The SWMP has identified and mapped the natural drainage routes that future development should respect. This information will be used when determining planning applications to ensure that development 'avoids increasing the risk of or from flooding' (in line with Core Strategy policy CS6).
Development that falls within an area of surface water flood risk should consider whether a) the layout could be modified to better respect the natural drainage routes and b) if Sustainable Drainage Systems (SUDS) could be incorporated into the development to reduce/mitigate the impact of the development.
Epsom & Ewell Surface Water Management Plan 2011 (pdf - 3.4mb)
Surface Water Drainage Areas Map (pdf - 1.58mb)
SUDS Suitability Map (pdf - 7.92mb)
Note on appropriate SUDS (pdf - 118kb)
Note on the maintenance of SUD (pdf - 193kb)