Mountfield Park, South Canterbury
|Key Personnel||Agnes Gannon, Fiona de Mauny, Guy Laister|
|Skillset||Flood Risk Assessment, Site drainage strategy using SuDS, foul drainage strategy|
|Project type||Urban extension of Canterbury city for 4,000 new homes along with a new district centre, schools and associated infrastructure including playing fields, public ridge park, roads and SuDS corridor.|
|Status||Resolution to grant Planning Permission 2016 subject to S106|
Water Environment Limited was commissioned in 2012 to advise the client and assist the masterplanners with a 4,000 house residential-led urban extension of Canterbury City on 232ha of agricultural land. A hybrid planning application was submitted to Canterbury City Council (CCC) in 2016 including detailed planning for the first phase of 140 houses and outline planning for the remainder of the development. Our scope included a Flood Risk Assessment and Sustainable Drainage System (SuDS) assessment for the proposed masterplan as well as more detailed assessments for the first phase. This required an integrated design approach. The masterplanners spearheaded a multi-disciplinary team of Planners, Architects, Environmental Engineers, Ecologists, Highways Engineers and Landscape Architects who effectively communicated the requirements of each discipline to converge on an appropriate solution for the large site area, with sufficient development of design to enable CCC to agree to resolution to grant Planning Permission.
The masterplan includes allowance for sustainable drainage throughout including a ‘SuDS corridor’ which will be constructed in the primary valley as part of a public woodland open space. New swales and watercourses will be constructed to convey surface water from the new development. The superficial geology varies across the site meaning infiltration devices are only likely to be effective in part. Water storage will primarily be provided in open attenuation basins and ponds with outfalls to existing ditches. Where land falls towards an existing sewer system, alternative solutions are being used such as green roofs and permeable paving as Southern Water do not accept surface water from open attenuation facilities.
The surface water drainage strategy was negotiated and agreed with Kent County Council (KCC), the Lead Local Flood Authority (LLFA) and drainage engineers at CCC such that there was no objection to the development. The drainage strategy was derived through the implementation of the SuDS Hierarchy alongside extensive knowledge of KCC and CCC preferred solutions based on past experience. Due to the size of the development, Southern Water were consulted prior to submission of the hybrid planning application. They advised that there is insufficient capacity in the public foul sewer system to accommodate the development. An exhaustive list of solutions was proposed, which resulted in the negotiation of a S98 requisition with Southern Water to provide a new sewer for the development direct to Sturry Road Waste Water Treatment Works (WWTW).
The planning committee at CCC resolved to grant planning permission in December 2016.