RFI - updated flood investigation report

      Further to this, a driveway has been included in the model to provide access that is immune
      in the 39% AEP. A 300mm RCP culvert is placed under the driveway within the existing swale
      drain.




      Figure 1-3: Existing 1% (2100) AEP flood levels in relation to Lot 1.


               Response to Information Request
      An Information Request was received on 21 January, 2022 as part of Reconfiguration of Lot
      Application No: RAL21/0033. Items 22 to 25 relate to Flooding, with response to each item
      detailed below:
      Issue: Flooding
      The Flood investigation:
          i.    includes comments regarding the impacts of “blockage of stormwater culverts” but
                does not indicate the impacts (depth, velocity) of “blockage” on the proposed new
                road, and
         ii.    does not include any comment regarding the probable maximum flood (PMF)
        iii.    does not include sufficient detail to demonstrate that the development (access and
                all lots) achieve compliance with The Flood Hazard Overlay Code – Performance
                Outcome PO4
        iv.     the investigation recommends that the floor levels be a minimum of 500mm above
                the flood level while the planning scheme requires 300mm.
      Information Request:
      22.     Provide additional detail on the impacts (depth, velocity, safety) of 100% blockage of
      the stormwater culverts on the proposed new road




21-0288-FS001-V3 | Flood Investigation | 60 Glenridge Drive, Cooroibah                                 |4