Appendix C - Engineering Report

6.4   Water Quality Management Plan


An assessment has been undertaken to determine whether the proposed development is
subject to State Planning Policy (SPP) water quality objectives. Trigger Questions have
been applied to the development to determine if SPP compliance is required. Refer to
Table 6.4a for details.


               Table 6.4a -State Planning Policy Trigger Questions
 SPP Trigger                                                    Response
 REC with Land Area >2500m² and >6 Lots                              No
 OPW with Disturbed Area >2500m²                                     No


The intended land use (low density residential plus balance rural allotment) is considered
low impact with respect to pollutant load generation when compared to typical urban
developments. The target pollutants for water quality management in new developments
are typically organics (phosphorous and nitrogen), suspended solids (sediment) and gross
pollutants (litter). A large percentage of these pollutants are released to downstream
waterways as a result of land disturbance associated with earthworks and building
operations. The proposed development works will include erosion and sediment control
measures during the construction phase and minimal pollutant load generation during
the operational phase.


Proposed new pavement areas will be directed to a vegetated swale drain (>100m) long
which will provide primary and tertiary water quality treatment prior to discharge at the
existing waterway. The high overall percentages of pervious surfaces within the site will
disconnect impervious areas and promote infiltration of stormwater runoff.




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