Reference Documents - MCU23 0058 (As Published)

                 Figure 2-4: Flood free area and 1% AEP (2100) DFE velocity contouring



                 2.1.3.      Filling and hydraulic performance
                 Currently the eastern portion of the building is built upon fill to 109.23m AHD to set the floor level, as
                 described in Section 2.1.1 above. The existing fill at the site forms a sloped batter with maximum grade of 1
                 in 5 from RL109.23m AHD to approximately RL108.00m AHD. Refer to Figure 2-5 for the approximate
                 extent of fill at the site based upon LiDAR.

                 The proposal seeks to modify the fill to a series of terraced benches that are 450mm high by 1800mm wide.
                 The modification will widen fill around the building past the existing fill’s batter toe. It is estimated that the
                 proposal will result in an additional 360m2 fill. For details regarding modifications to fill onsite refer to
                 Figure 2-6.

                 Performance object P03 (table 8.2.6.3) of the Noosa Plan 2020 Flood Hazard Overlay states that “for
                 reconfiguring a lot or operational works, development is undertaken in a manner that ensures (a) natural
                 hydrological systems are protected from erosion, scour or flood damage on the premises or other premises; (b)
                 natural landforms and drainage lines are maintained to protect the hydraulic performance of waterways and
                 flood plain; and (c) development integrates with the natural landform rather than modifying the landform to suit
                 the development as far as practicable.”

                 The following performance solution is proposed to meet performance objective PO3:

                      •    Fill is provided to achieve minimum floor level of 109.230, satisfying performance objective PO1.
                      •    Terracing is stabilised with retaining walls to protect the proposed development from erosion,
                           scour or flood damage.
                      •    Existing swales that are impacted by the extent of proposed are re-established at the site as shown
                           in Figure 2-7 to maintain drainage lines at the site.
                      •    Extent of fill is minimised, balancing the need to meet other performance objectives described in
                           the flood hazard overlay. The proposed increase in fill footprint is approximately < 20% and is
                           minor in comparison to the overall floodplain area.




                 23-0102-SMP01-V1A | Preliminary Stormwater Management Plan | Cooroy Sportsground Preliminary SMP Page 6

Document Set ID: 22785418
Version: 1, Version Date: 29/01/2024