Strategic Flood Risk Assessment - South Worcestershire ...

Sources of Flood Risk:Primary flood risk is fluvial resulting from overtopping of an unnamed watercourse tothe north of the development site. The site is fully within the historic flood map(Flood Zone 2). Note: the 2007 historic flood map in this location has beenquestioned by council drainage officers and is in the process of being investigatedby the Environment Agency. This could potentially mean this area may be removedfrom future EA Flood Zone mapping.Surface water may present a risk to the site. Further development and creation ofimpermeable surfaces may result in an increase of surface water flood risk.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.Soil TypeGreenfield Runoff Rate (l/s/ha)Unknown – More PermeableEstimated Attenuation Storage Volume (m 3 ) 251.3 – 351.41 in 2 year 8.41 in 100 year (plus climate change) 32.02012s5947 S Worcestershire Level 2 SFRA Update FINAL Report v1.0.doc 53