Level 2 Strategic Flood Risk Assessment (.pdf ... - Wigan Council

EA comment:Supplementary design guidance including minimum floor levels, access and egress, sitelayout recommendations in relation to vulnerability, building materials and flood resilientconstruction,The SFRA mapping provides graduated depths of flooding for the entire borough.However, as previously discussed this is often based on strategic mapping techniques asthe EA could not provide significant elements of detailed modelling data. This mappingprovides the user with an indication of the design levels, allows identification of accessissues, identifies (in accordance with the recommendations) those areas of each site thatare at greatest risk and were open space and water compatible uses would be mostappropriate.Again the implied level of detail is not commensurate with the accuracy and detailprovided by a high level strategic study. For instance, if a developer comes forward withproposals that avoid high risk areas, then predefining “site layout recommendations inrelation to vulnerability, building materials and flood resilient construction” would clearlybe inappropriate.EA comment:Overall site-by-site summary guidance suitable for issuing to potential developers.As previously explained we have produced a succinct SFRA. We do not intend to try andsummarise the information further as key messages will invariable become diluted.EA comment:Mitigation options, and potential delivery mechanisms should be presented as part of theLevel 2 SFRA.Other EA regions have recognised, more fully, the link between the SFRA, PFRA andSWMP. Opportunities for large scale mitigation have been identified in the SFRAmapping. However, the suitability or these potential locations will be primarily dependenton the outcomes and recommendations in the SWMP.We would also like to reiterate that the EA have not provided any detail of the RiverDouglas FRM strategy. It is understood that this scheme will reduce further flood risk tosites within the Wigan catchment.EA comment:Wigan SFRA User GuideParagraph 4.7.1 Allowable Discharge RatesPlease advise further?2009s0578-S-L007-1.doc 6/710 December 2010www.jbaconsulting.co.uk