SWMP change reps

Potential Causes

         •      Leaks from parked vehicles within the completed development.
         •      Washing of vehicles within the completed development.

Mitigating Measures

         •      Fall driveways and parking areas towards adjacent landscaped strips, vegetated swales
                and the bioretention bed.

Nutrient Runoff:

Nutrients such as Nitrogen and Phosphorus can be mobilised and transported in Stormwater runoff from
the site. This can compromise Water Quality Objectives.

Potential Causes

         •      Runoff from hard surfaces within the site.
         •      Detergents used in car washing and similar activities.
         •      Fertilisers used in propagation of landscaped areas.
         •      Embodied nutrients contained in silt (topsoil) runoff.
         •      Embodied nutrients contained in runoff.



Mitigating Measures

         •      Fall vehicles pavement areas towards landscaping areas and the bioretention bed.
         •      Implement management plan for landscaping propagation. Use stable organically bound
                fertilizers cultivated immediately prior to turf placement. Mulch over areas of exposed
                topsoil.
         •      Construction of silt fences during construction and maintained beyond completion of
                landscaping.
         •      Drain stormwater runoff through the Bio Basin.
         •      Capture roof runoff and store for re-use.

5.3.3    Proposed Treatment Measures
Implementing the water quality objectives for the site as mentioned above and to ensure that on-site
stormwater management facilities can be economically maintained, it was deemed the most appropriate
method for treatment is the inclusion of small grass swales and bio-retention basins. Roof and surface
runoff will be collected via an internal drainage network and directed to the on-site bio retention basins
prior to the lawful point of discharge.

SCG Consulting Engineers                    Page 12                           SCG Ref: 33132(SWMP).RevC