The Planning System and Flood Risk Management - Offaly County ...

• Whether it will increase flood risk elsewhere;• Whether there are appropriate measures to deal with these effects andrisks; and• Whether the risks will be reduced to an acceptable level to enable thepassing of the Justification test if this is appropriate.65In some instances improvements to existing flood defences may be requiredto manage residual flood risks. Where such flood defence works are considered,the SFRA should include an appraisal of the extent of any works required toprovide or raise the flood defence to an appropriate standard.Site-Specific Flood Risk AssessmentsThe key outputs from a site-specific FRA and the key steps in their deliveryare:Plans• A location plan that includes geographical features, street names andidentifies the catchment, watercourses or other bodies of water in thevicinity;• A plan of the site showing:- Existing site- Development proposals;• Identification of any structures, which may influence local hydraulics.This will include bridges, pipes/ducts crossing the watercourse, culverts,screens, embankments, walls, outfalls and condition of channel.Surveys• Site levels related to Ordnance Datum, both existing and proposed;• Appropriate cross-section(s) of the site showing finished floor levels orroad levels, or other relevant levels relative to the source of flooding,and anticipated water levels and associated probabilities.Assessments• Consideration of the flood zone in which the site falls and demonstrationthat development meets the vulnerability criteria set out in this Guidance;• Flood alleviation measures already in place, their state of maintenanceand their performance;• Information about all potential sources of flooding that may affect thesite – from rivers and the sea, streams, surface water run-off, sewers,groundwater, reservoirs, canals and other artificial sources or anycombination of these;Planning Guidelines