The Environment Agency’s flood map for planning shows the site to be located entirely within Flood Zone 1, land defined as having the lowest probability of river or sea flooding (less than a 1 in 1000 annual probability). The nearest flood zone is shown to be located approximately 550m north of the site, associated with the Footherley Brook.
There are however areas of surface water within the site, including a pluvial flow route present within the west of the site where built development will be avoided. A bespoke hydraulic modelling exercise is being undertaken to confirm the extent of surface water flow routes, making allowance for the impacts of future climate change. None of the potential surface water flood risk sources are thought to represent a potential barrier to development. This will be confirmed as part of a Flood Risk Assessment which will assess and set out the strategy to mitigate any identified risk.
The additional surface water runoff generated by the development will be managed through the implementation of a drainage strategy which will include Sustainable Drainage Systems (SuDS). This will ensure that surface water discharge rates do not exceed existing levels and runoff from the site is managed in accordance with local and national guidance.
Due to the topography of the site, and existing site constraints, the site will be split into several drainage catchments. This approach aims to treat and attenuate surface water runoff as close to its source as possible, with surface water runoff from each catchment being stored within infiltration basins. With appropriate planting, the proposed attenuation areas will also deliver amenity and biodiversity benefits through the provision of new habitats.
The site is entirely underlain by Chester Formation (Interbedded sandstone and conglomerate) and therefore soakaway testing has been undertaken which confirms infiltration is viable. Alternatively, a connection to the existing surface water sewer will be explored in liaison with Severn Trent Water.
Foul water will be directed to the local public sewers. Taylor Wimpey will work with Severn Trent Water (the operator) to ensure that any necessary upgrades to the local sewer network are delivered. It is expected that a foul pumping station may be required within the site and this would be located at the lowest point within the developable area and would require a 15m cordon sanitaire. The pumping station would have vehicular access appropriate for a tanker and be designed in accordance with the latest guidance.
A Sustainable Drainage System (SuDS) for the site will ensure that surface water discharge rates do not exceed existing levels, while providing new wetland habitat to enhance biodiversity.