Att8 - SWMP

 STORMWATER QUALITY MANAGEMENT

     4.1. Operational Stormwater Management
The site is a large rural catchment with only a relatively small area of the site proposed for development resulting in
insignificant changes to the overall impervious area of the site. In accordance with the State Planning Policy Appendix
2 Table B, the stormwater development objectives would be applicable for:

1) A Material Change of Use for an urban purpose that involves premises 2500 metres2 or greater in size and:

     a) will result in six or more dwellings; or

     b) an impervious area greater than 25 per cent of the net developable area.

2) Reconfiguring a lot for urban purposes that involves premises 2500 metres2 or greater in size and will result in
   six or more lots.

As a rural development maintaining a typically pervious characteristics (approximately 97.8% pervious), the
development is not required to achieve the operational targets for stormwater quality, with the impacts to water
quality more likely to occur during construction and earthworks phase of the development.

To ensure minimal impacts on downstream waterways and receiving environments, a number of water quality best
practice strategies will be implemented to reduce stormwater sediments and pollutants being discharged from the
development. These main strategies are:

1) Stormwater run-off from impervious surfaces will be graded as overland sheet flows across the vegetated areas
   to provide:

     a) groundwater replenishment through infiltration;

     b) filtration and treatment of pollutants through grassed buffers providing nutrient uptake; and

     c) minimise risk of erosion and maintain existing flow paths by ensuring run-off discharges as sheet flows along
        the natural contours of the site

2) Rainwater reuse tanks to be provided to each residential village which will:

     a) Reduce sediments and nutrients being discharged from the site; and

     b) Achieve water conservation by providing reuse for potable demands.


     4.2. Construction Stormwater Management

          4.2.1 Erosion and Sediment Control Measures
During construction, earthworks may result in large areas of exposed soils that are vulnerable to sediment transport
and potential contamination of downstream waterways. A range of best practice sediment and erosion controls will
be implemented within the development to mitigate any negative impacts to the downstream receiving
environment. The erosion and sediment control strategy should be based on the following key principles

     •    Minimise the disturbed area – The clearing of land should be limited to areas actively under construction or
          those that will be in the near future (3 to 6 months)

     •    Treatment of disturbed areas – where significant areas of soils are exposed, sediment basins shall be
          provided downstream with cut-off drains used to ensure all run-off from the exposed areas is diverted to the
          basin for treatment prior to release from the work zone.



Project number 20220146                                                                                    Page 10 of 20
File RECOR Stormwater Management Plan- 20220146.docx, 2022-09-06 Revision 0

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