Strategic Flood Risk Assessment - South Worcestershire ...

Sources of Flood Risk:Primary flood risk to the site is fluvial, resulting from overtopping of the unnamedtributaries of the River Severn, to isolated areas the west of the site and south-westcorner. The south-west corner of the site falls within Flood Zone 2, with a very slightencroachment of Flood Zone 3 to the central-west edge of the site. The centralwesternportion of site falls within the Blue Zone of the Policy Maps.Photographic evidence provided by Claines Flood Action Group from 2007 showhistoric flooding to part of the site – this is supported by the 2007 historic flood mapwhich is to be incorporated into the EA’s Flood Zone 2.Surface water presents a very low risk to the site. Further development and creationof impermeable surfaces may result in an increase of surface water flood risk. Thesouthern arm of the Northwick Road, the main access road to the site, falls within anarea of surface water though the northern arm is shown not to be at risk on themapping.Surface Water Drainage:As an indication of requirements to manage surface water runoff at the development site anassessment of the soil types, greenfield runoff rate and attenuation storage volume is includedbelow. Storage volumes displayed are calculated with an assumption that 75% of the site will bedeveloped impermeable ground. A 25% increase in rainfall depths has been included torepresent predicted future climate change effects.PLEASE NOTE: This assessment has been carried out using broad-scale datasets and aims toprovide an indication of the likely opportunities and constraints for this development site. Adetailed drainage assessment based on site-specific conditions should be carried out by asuitably qualified professional and submitted with any planning application. The values belowshould not be used for design purposes.2012s5947 S Worcestershire Level 2 SFRA Update FINAL Report v1.0.doc 75