Approved Plans - RAL21/0033

      EXECUTIVE SUMMARY
      PEAKURBAN Pty Ltd have been engaged by Mark Bain to prepare a Flood Investigation in
      support of a development application to Noosa Shire Council (NSC) over land located at 60
      60 Glenridge Drive, Cooroibah (Lot 47 RP 860577). This development application seeks a
      development permit for a Reconfiguration a Lot (ROL) to create 8 rural residential lots.
      The site is influenced by two unnamed tributaries of the Noosa River. Both catchments extend
      upstream across McKinnon Drive to the west and join at the eastern boundary of the site. The
      total catchment of both tributaries is 130ha. The catchment is characterised by steep upper
      catchment and flattens out along the lower part of the flood plain. Elevations on site range
      from 10 to 44m AHD.

      Suitable flood immunity is achievable for future dwellings on the site, with the recommended
      minimum building envelope / finished floor level (FFL) for each lot has been taken as the
      greater of the DFE + freeboard (0.3m) or the PMF (refer Table 4-5). Each lot will be have a
      place to refuge above Probable Maximum Flood within the future dwelling.
      The investigation has found that there is a no off-site impacts, reduction in peak flows and
      increase in flood storage provided. As such, any further formal on-site detention is not
      recommended as development has been designed to achieve the outcome of non-
      worsening.
      A flood risk assessment was completed which identified that the use of the building envelope
      as a flood refuge should a flood event greater than the 1% AEP occur.
      The new internal road will achieve flood immunity in the 10% AEP and remain trafficable in the
      1% AEP event. A 9 x 1200 (w) x 600 (h) box culverts are proposed under the road crossing.




21-0288-FS001-V5 | Flood Investigation | 60 Glenridge Drive, Cooroibah                                 |i