13. Appendix I - Integrated Water Mangement Plan

                                                                                                      Integrated Water Management Plan
                                                                                              Noosa Marketplace : 2-20 HOFMANN DRIVE



6.4.4         Impacts of Development
The impacts to peak flood levels at the reporting points are summarised in Table 6.3. As outlined above, the
proposed development forms a partial blockage of the flow path and hence increases the peak flood levels
North of the development area within the Eenie Creek Road reserve. The flood level increases do not extend
beyond the site boundary to the west of the site.
To the north of the site, increases in flood level in the order of 600 mm extend beyond the site boundary.
However, these increases occur only within the road reserve in a bush land area that is inaccessible to the
public. Water levels remain approximately 800 mm below the level of the road pavement in the 1% AEP event.
In the existing case, flood depths of up to 1 metre already exist at this location with the existing topography
acting as a detention basin. Therefore, the proposed development further enhances this natural function with
no actionable nuisance.
Due to the enhancement of the natural detention basin by the development, reductions in peak flood levels
during the 1% AEP event are indicated along a significant section of Hofmann Drive, as shown in Figure B13
App B. Flood impact mapping for all events modelled is shown in Appendix B with all results indicating a
reduction in peak flood levels along Hofmann Drive.
Table 6-3       Flooding Impacts (m)
                                                        Flooding Impacts (m)
    Location            39% AEP            20% AEP             10% AEP              5% AEP                2% AEP         1% AEP
        P1                -0.14               -0.01               0.08                0.10                 0.18            0.23
        P2                 0.11                0.23               0.24                0.27                 0.33            0.36
        P3                 0.00                0.00               0.00                0.00                 0.00            0.00
        P4                 0.14                0.25               0.28                0.32                 0.37            0.41
        P5                 N/A                 N/A                 N/A                 N/A                 N/A             N/A
        P6                 0.00               -0.04               -0.03               -0.02                -0.02          -0.02
        P7                -0.03               -0.04               -0.06               -0.06                -0.08          -0.13
        P8                -0.03               -0.04               -0.05               -0.05                -0.07          -0.09
        P9                 0.00               -0.02               -0.01               -0.01                -0.01          -0.02
        P10                N/A                 N/A                 N/A                 N/A                 N/A             N/A

*N/A meaning that the point of interest is out of the flood waters or located on a development building




V190428 | 15 May 2019 | Commercial in Confidence                                                                                   23