Revised Stormwater Management Plan

                              STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust                                Location: Taylor Court, Cooroy

As the results in Table 6 demonstrates, the stormwater quality management strategies proposed
for the proposed Highway Service Station far exceed the target reduction rates required by the
NSC and the State Planning Policy (2014). The pollutant reduction rates exceed those required by
NSC and SPP to ensure the concentration of pollutants discharging from the site are close to the
WQOs for freshwater within the Lake Macdonald catchment as per Table 2. Table 7 below
indicates the daily concentrations of pollutants determined to potentially leave the site identified
through MUSIC modelling.
                                       Table 7 Daily Pollutant loads

                           Pollutant          WQOs                 MUSIC Model
                             TSS                    6                  18
                             (mg/l)
                              TP                 50                    42.1
                             (µg/l)
                              TN                500                    525
                             (µg/l)


5.0 MAINTENANCE PERIOD
5.1 Bioretention Basin

The proposed bioretention basin will require consideration and management during both the
construction and operational phases of the development. In order to establish vegetation and
treatment functions in the bioretention system, the filter media must be protected from pollutants
commonly generated in the construction phases. During the operational phase, regular
maintenance of bioretention system is required to ensure comprehensive vegetation
establishment, a critical component in stormwater pollutant uptake. Below are details on the
general maintenance periods and requirements for the construction and operational periods.

5.1.1 Maintenance During ‘Construction Phase’

Erosion and sediment control devices will be installed at the commencement of all the staged
works to capture and treat runoff during construction works. The sediment control devices should
be cleaned out as required and at the end of the works. During the construction stage, all sediment
control devices are to be inspected weekly, after runoff generating rain events and prior and after
prolonged site shut downs (e.g. holiday periods).

Following construction of the roadways and buildings on site the basin will be constructed to the
final design and filter media layers and plants will be installed. Leaving the completion of the
bioretention basin until after construction is completed will prevent any potential clogging of the
system during the construction period.

5.2 Rainwater Tank and Stormsacks

Maintenance for the proposed rainwater tank and Stormsacks will follow manufacturers guidelines
and recommendations to maintain the products lifespan.




Covey Associates Pty Ltd                        7                                     Project No: 161968
Consulting Engineers                                                                     100415 Rpt Iss B