Attachment 7- Site Based Stormwater Management Plan

Stockpiles

Stockpile locations should be identified before the commencement of works. Ideally, they
should be located in a flat area at least 15m from any water body or stormwater inlet.
Sediment fences should be installed downslope of all erodible stockpiles, and upslope
protection measures should be used (i.e. sandbags or sediment fence) to divert runoff in
the event of rain. At the end of each working day stockpiles should be covered with geofabric
if rain or high winds are forecast.

Street Sweeping

Ensure that local roads are swept as required. This will minimise the potential for sediment
tracked onto the road to be washed into the stormwater system. If a large quantity of
sediment is being tracked onto the surrounding streets the stabilised entry/exit point may
need to be raked or reinforced with rock to provide more effective sediment removal for
vehicles.

Erosion Control Matting and Permanent Stabilisation

Exposed areas onsite should be permanently stabilised (i.e. with turf) as the construction
works progress. Erosion control matting or mulching should be used as a temporary
measure to stabilize exposed areas before permanent stabilisation can be undertaken.

Monitoring

Monitoring and recording of the performance of the drainage control devices including are
to be undertaken in accordance with local government requirements. It is further
recommended that the proposed construction works are undertaken during periods of dry
weather to reduce the potential for sediment to be transported off site during construction.



4.2 OPERATIONAL PHASE

The internal drainage system has been designed to include SQIDs in the water quality
treatment train for the proposed development. Refer to the conceptual drainage plans in
Appendix A for details.


4.2.1 Bioretention Basin

Bioretention basins are densely vegetated filtration devices, where runoff (for small/frequent
storm events) enters the basin and is filtered through a filter media layer (e.g. sandy loam)
as it percolates downwards. Bioretention basins often have an extended detention volume
above the filter media which increases the volume of runoff treated through the system.
The runoff is treated as it passes through the system through fine filtration, absorption, and
Site Based Stormwater Management Plan                                             Page 7 of 20
1856-SBSMP-01_Version 2.0 (April 2019)