We were appointed to undertake the civil engineering works associated with this major re-generation scheme in Woking. This complex project involves the demolition of existing dwellings and the construction of up to 1,200 new homes with associated highway, drainage and landscaping infrastructure. A leisure centre including external playing pitches was also part of the overall development proposals.
Our work included a detailed Flood Risk Assessment (FRA) and Sustainable Drainage System (SuDS) design for the 30ha site. Existing flood modelling has shown extensive overland flows entering the site from off-site. To protect the development from possible flood risk, the new park area has been designed as a temporary detention area for flood waters during storm flood events. This has been agreed with the Environment Agency and Lead Local Flood Authority (LLFA) as part of early discussions and negotiations.
Strict restrictions on allowable outflows from the site were imposed by the LLFA which required extensive attenuation on site. SuDS systems such as permeable paving, rain gardens and below ground attenuation tanks were specified to address the site constraints, which included a high groundwater table and shallow outfall.
A new wetland which would act as an attenuation basin during rain events was also proposed in the new park area which added to the biodiversity and amenity value of the site.
Our work also included an extensive cut and fill model of the site to quantify earthworks volumes which fed into the site viability model.