Swmp

If the proposed development maintains pre-development flow conditions, the lawful points of discharge
for the subject site is into the existing inter-allotment stormwater drainage infrastructure within Lots
102, 107, and 108 SP 106085 and Starboard Avenue, east of the site, and the Headland Drive stormwater
infrastructure. The proposed lawful point of discharge is considered to be compliant with the criteria
outlined in QUDM 2017 see below: -

         1.     The proposed development stormwater discharge will not alter the existing site’s
                stormwater discharge characteristics.
         2.     The location of the proposed discharge point is under the lawful control of the local
                government.
         3.     Authority to discharge over affected properties will not be required as the proposed
                development will discharge as per existing drainage conditions.




5.0      STORMWATER QUALITY


In the absence of adequate controls, urban development can increase both stormwater runoff volumes
and peak discharge rates. In addition, this urban development has the potential for increased creek
erosion and the stressing of in-stream aquatic ecosystems. The use of stormwater detention or retention
systems aims at reducing these threats by limiting property flooding to acceptable levels and also
filtering stormwater runoff through a vegetated soils media layer, thus reducing the threats caused by
urban development.

The following factors have been identified as potential contributors which can adversely affect
stormwater quality draining from the site:-

         •      Silt and sediment erosion
         •      Gross Pollutants
         •      Hydrocarbon runoff
         •      Nutrient runoff



5.1      State Planning Policy and Water by Design Assessment
The proposed development has been assessed against the State Planning Policy 2017 and the Water By
Design (Stormwater Quality Deemed to Comply Solutions – 2010).

The proposed residential development involves a land area greater than the trigger value of 2500m2 for
stormwater quality measures as required in the State Planning Policy 2017 and the Water By Design -
SCG Consulting Engineers                    Page 8                           SCG Ref: 33132(SWMP).RevB