Stormwater Management Report · MCU22/0087.01

                      Table 0.1 Existing and proposed site peak discharge rates (unmitigated)

          A.E.P      Qy Pre (m3/s)     Qy Post (m3/s)     Qchange (m3/s) Qchange (%)
           63.2% AEP             0.013              0.013          0.000                              0%
             50% AEP             0.019              0.019          0.000                              0%
             20% AEP             0.023              0.023          0.000                              0%
             10% AEP             0.030              0.030          0.000                              0%
              5% AEP             0.034              0.034          0.000                              0%
              2% AEP             0.039              0.039          0.000                              0%
              1% AEP             0.042              0.043          0.001                              2%



Based on the modelling, the minor increase to impervious area from the proposed development will only result in
an increase of 1L/s for the 1% storm AEP event, being a change of only 2% The pre-post comparison found that
under all other storm events up to the 1% AEP analysed not resulting in an increase of the peak flows. As such, the
proposed development is considered to not impact the downstream receiving environment in a manner that will
alter the catchment hydrology or result in nuisance run-off that may impact downstream properties.

As peak outflows from the development are typically as per existing conditions, no stormwater attenuation is
required to control outflows from the proposed development.




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