EAS also produced a Flood Risk Assessment and SuDS Report for the outline application. Following NPPF guidance, although the site was in Flood Zone 1 as the site area exceeded 1ha a Flood Risk Assessment was completed. EAS evaluated all sources of flooding and concluded the risk from all sources was low. As a result, EAS were able to inform the project team that no specific mitigation measures were required.
Initial review of the site topographic survey, British Geology Survey records and local sewer mapping highlighted the need to further explore surface water drainage options at the site. A site visit confirmed the absence of a suitable watercourse to outfall to. Following the SuDS hierarchy, EAS liaised with Anglian Water to achieve an agreement in principle to outfall to a nearby foul sewer. Due to the proximity of the site to London Stansted Airport and the risk posed by bird strikes, the use of above ground SuDS features like ponds is prohibited. Nonetheless, EAS designed a SuDS scheme comprised of permeable paving and swales, exceeding the water quality requirements set out in the CIRIA SuDS Manual C753.
As is now commonly the case, the demands of SuDs affect the site layout and in this instance the access position and associated visibility splays. Having both sets of expertise ‘in-house’, EAS were able to efficiently find solutions allowing the various elements to work together.