Att8 - SWMP

Table 5.2 Catchment C1 Modelling Results

                                                                                 Catchment C1
              A.E.P                                                                                                                                                Qchange (%)
                                            Qexisting (m³/s)                      Qproposed (m³/s)                       Qchange (m³/s)
                             1EY                          2.69                                 2.69                                                 0                               0.0%
                             50%                                  3.06                                  3.11                                   0.05                                 1.6%
                        0.2 EY                                    5.69                                  5.70                                   0.01                                 0.2%
                             10%                                  6.98                                  7.01                                   0.03                                 0.4%
                              5%                                  8.56                                  8.55                                 -0.01                                 -0.1%
                              2%                                  9.99                                  9.98                                 -0.01                                 -0.1%
                              1%                               11.15                                  11.14                                  -0.01                                 -0.1%


As shown above, modelling of the pre and post development conditions for peak flows arising under each storm
event has found that the development will modify peak flow rates from the site to a maximum of 1.6% increase upon
the existing levels when considering only the catchment within the site. When including the upstream catchments
being conveyed through the drainage path, the maximum increase is reduced to only 1.1% beyond the existing.
Within the rural context of the site, this increase is insignificant and on site attenuation is not considered necessary.


      5.2. Rainwater reuse assessment
The development will rely on rainwater capture from roof areas to provide for the water demands of the camp
during operation. Rainwater will need to be treated to an adequate standard using UV sterilisation and media
filtration, and potentially chlorine dosing to ensure it is suitable for potable water uses and food preparation. While
rainwater may also be used for non-potable reuse demands, the existing dams and bore water supplies would be
preferable to minimise unnecessary drawdown of potable water supplies

An assessment of the required demand produced by the facility has been carried out using average rainfall at the
closest BOM site at the Tewantin RSL Park (ID:040908). Average day demands for potable and non-potable water
has been based on the SEQ WS&S D&C Code - Design Criteria (SEQ Code).

From Section 5.2 of the Noosa CYC Campsite Master Planning report (Planning Report), a total of 160 Equivalent
Person (EP) has been used as the basis for 100% occupancy, with these equivalent persons distributed between
each village as follows:

      •       Village 1 – 140 person – 75 EP
      •       Village 2 – 100 person – 53 EP
      •       Village 3 – 60 person – 32 EP

Based on the average rainfall across the year compared to the daily demands, there will be insufficient supply from
rainwater inflow for the total demand value when considering an occupancy rate of 100% capacity of the facility
across the year and water will need to be imported by tankers to supply the shortfall as shown in Figure 5-1.

BOM - Site ID 040908                          Jan          Feb          Mar          Apr          May          Jun           Jul         Aug          Sep          Oct          Nov          Dec
Average days/month                             31           28           31           30           31           30           31           31           30           31           30           31
Mean rainfall (mm) for years 1996 to 2022       146.4        162.6        176.7        128.6        126.2        100.6           58.2        26.4         29.2         82.1         78.3       133.0
Generated RO/month                        1,038,837.93 1,153,791.30 1,253,843.32 912,531.13 895,501.00 713,846.28 412,980.65          187,331.43   207,199.91 582,572.36 555,607.99 943,753.04
Demand/month                              1,537,600.00 1,388,800.00 1,537,600.00 1,488,000.00 1,537,600.00 1,488,000.00 1,537,600.00 1,537,600.00 1,488,000.00 1,537,600.00 1,488,000.00 1,537,600.00
Surplus/deficient                         -498,762.07 -235,008.70 -283,756.68 -575,468.87 -642,099.00 -774,153.72 -1,124,619.35 -1,350,268.57 -1,280,800.09 -955,027.64 -932,392.01 -593,846.96
Storage
Surplus/deficient

DWG ID                                  Area (m2)
Village 1                                2372.19987
Village 2                                3092.70257
Village 3                                1630.98504
Communal dining hall                     3233.31311

                                          10,329.20

No. EP                                           160
Drinking water AD/ day                          36.8
Non-drinking water AD/ day                      12.8
Water Demand (kL) / day                         49.6

Figure 5-1 - Potable and non-potable water demands at 100% Occupancy

Project number 20220146                                                                                                                                                            Page 14 of 20
File RECOR Stormwater Management Plan- 20220146.docx, 2022-09-06 Revision 0

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