Appendix F - Flood Study

                                                                                                         Flood Study
                                                                                               Noosa Care - Carramar




5                Results
5.1              Comparison with Previous Modelling
5.1.1            Peak Flows
The peak flows generated in the 2017 model match well with the 2006 study, as shown in Table 5-1.

Table 5-1        Flow Comparison
                                              1% AEP Peak Flow
      Flow Comparison                              (m3/s)
          Location
                                 2006 Flood Study                RORB
       Location A/
                                       10.0                       12.4
    Cooroy Noosa Road
        Location C /
                                      122.7                       122.8
      Golf Course Drive

5.1.2            Peak Water Levels
The peak water levels were compared to the results of the 2006 study, as shown in Table 5-2. The location
of the cross-sections is provided in Figure 2-2.
The site is located between cross-sections 3 and 4 on the East Tributary branch. The peak water levels match
well with the results of the original flood study, particularly for the area immediately around the site. At cross-
sections 4 and 6 a range of water levels from the 2D model has been provided as the water levels are variable
in these locations. Cross-section 4 is located around the dam outlet and cross-section 6 is located at the
confluence of the two streams.

Table 5-2        Flood Level Comparison
                                                            Water level
                  2006 Flood Study
                                                             (m AHD)              Difference
                                                                                      (m)
                                                    1% AEP           1% AEP
      Branch        Cross-section    Chainage
                                                     (2006)           (2017)
 Wooroi Creek             1            780           8.13                 8.35        0.22
 Wooroi Creek             2            540           7.10                 7.66        0.46
 East Tributary           3            900           8.45                 8.50        0.05
 East Tributary           4            700           7.45          7.11 to 8.06        -
 East Tributary           5a           520           7.42                 7.05       -0.37
 East Tributary           5            480           7.10                 7.02       -0.08
    Confluence            6            440           7.00          6.92 to 7.37        -
    Confluence            7            240           6.82                 6.97        0.15
    Confluence            8             0            6.53                 6.59        0.06


5.2              Climate Change
Since the original 2006 flood study was prepared, it is now required to consider the potential impacts of climate
change when defining the flood levels for a site. The 1 and 10% AEP climate change events were therefore
analysed. The resultant peak water levels at the original cross-section locations are provided in Table 5-3.




24 July 2017                                          Cardno                                                     11