13. Appendix I - Integrated Water Mangement Plan

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



              RAFTS Catchments

 Catchment          Total Area      Percentage Impervious         Vectored Slope       Catchment Manning’s 'n'
 ID                    (ha)                  (%)                       (%)                  Perv/Imperv

 1                     2.31                      95                    2.96                   0.045/0.015
 2                     0.77                      95                    5.10                   0.045/0.015
 3                     0.60                      95                    5.20                   0.045/0.015
 4                     0.69                      95                    3.36                   0.045/0.015
 5                     1.17                      50                    3.39                   0.045/0.015
 6                     0.34                        0                   1.81                   0.045/0.015
 7                     0.18                        0                   1.22                   0.045/0.015
 8                     1.15                      95                    1.34                   0.045/0.015
 9                     0.46                      95                    1.56                   0.045/0.015
 10                    0.88                      50                    1.41                   0.045/0.015
 11                    0.09                      50                    0.31                   0.045/0.015
 12                    0.06                      95                    0.84                   0.045/0.015
 13                    0.14                        5                   1.86                   0.045/0.015
 14                    0.53                        5                   2.07                   0.045/0.015
 15                    0.54                        0                   0.78                   0.045/0.015
 16                    0.16                        5                   0.09                   0.045/0.015
 17                    0.45                        0                   2.48                   0.045/0.015
 18                    0.17                      35                    3.58                   0.045/0.015
 19                    0.14                        0                   1.52                   0.045/0.015
 20                    0.42                        5                   1.28                   0.045/0.015
 21                    1.53                      95                    0.92                   0.045/0.015

Table 3-2     Initial and Continuing Losses for RAFTS Modelling
 AEP Event      Initial and Continuing Losses
 1%             0mm IL/2mm/h CL
 2%             5mm IL/2mm/h CL
 5%             5mm IL/2mm/h CL
 10%            10mm IL/2mm/h CL
 20%            10mm IL/2mm/h CL
 39%            10mm IL/2mm/h CL

A range of design storms were modelled with 10 differing temporal patterns and multiple durations as per ARR
2016. The maximum median storm was then used as the peak design flow.

3.2.4       Rational Method Verification
The peak flows determined using RAFTS were compared with peak flows determined using the Rational
Method. Catchments 2 and 3 were chosen for this comparison due to having clearly defined drainage lines
and catchment boundaries. C10 values were sourced using Table 4.5.3 of the Queensland Urban Drainage
Manual 2017. The results of this verification are shown in Table 3-3 below for the 1% AEP event. It was found
that the RAFTS model produced higher peak flows than the Rational Method for Catchments 2 and 3. The
RAFTS flows were therefore considered acceptable.




V190428 | 15 May 2019 | Commercial in Confidence                                                                     8