Strategic Flood Risk Assessment - South Worcestershire ...

SUDS and the development site:SUDS TypeSource ControlInfiltrationDetentionFiltrationConveyancePotentialSuitabilityCommentsAll forms of source control are likely to be suitableMapping suggests the underlying soil type may hinder theperformance of such devices and therefore would not be viableMapping suggests that the site slopes are suitable for all forms ofdetentionMapping suggests that filtrations would be suitable but require a formof liner to prevent ingress of groundwater into the SUDS systemAll forms of conveyance are likely to be suitableFlood Defences:None.This site is located within a flooding hotspot so all efforts should be made tominimise the rate and volume of runoff leaving the site.The site is not located within a groundwater source protection zone.Residential and commercial developments should provide at least two independentSUDS features in series to provide a suitable level of water quality treatment.Effects of Climate Change:Increased rainfall intensity. Increased flood risk from the River Avon.Flood Risk Implications for Development:All development should be located within Flood Zone 1.A detailed site-specific flood risk assessment, including hazard mapping, will berequired for any development in Flood Zone 2, or for sites greater than 1ha in FloodZone 1.Flood Zone 2 should be used as public open space with the potential for a buffer.Resilience measures will be required if buildings are situated in the flood risk area.Green infrastructure should be considered within the mitigation measures for surfacewater runoff from potential development.Assessment for runoff should include allowance for climate change effectsNew or re-development should adopt exemplar source control SUDS techniques toreduce the risk of frequent low impact flooding due to post-development runoff.Onsite attenuation schemes would need to be tested against the hydrograph of thereceiving watercourse to ensure flows are not exacerbated downstream within thecatchment.The main access roads; A4184 Abbey Road, Abbey Lane and Boat Lane are at riskof fluvial flooding and \ or surface water. Suitable alternative access arrangementsaway from the floodplain will need to be investigated further.Demonstration that development at this location can be made safe.2012s5947 S Worcestershire Level 2 SFRA Update FINAL Report v1.0.doc 48