Stormwater Report

         Issue             Desired Outcomes



                           4. Provide emergency spillways for sediment basins to achieve the
                              construction phase stormwater management design objectives for
                              emergency spillways on temporary sediment basins (part 3).




Erosion Control            1. Stage clearing and construction works to minimise the area of exposed
                              soil at any one time.
                           2. Effectively cover or stabilise exposed soils prior to predicted rainfall.

                           3. Prior to completion of works for the development, and prior to removal
                              of sediment controls, all site surfaces must be effectively stabilised
                              using methods which will achieve effective short-term stabilisation.

Sediment Control           1. Direct runoff from exposed site soils to sediment controls that are
                              appropriate to the extent of disturbance and level of erosion risk.

                           2. All exposed areas greater than 2500 metres must be provided with
                              sediment controls which are designed, implemented and maintained
                              to a standard which would achieve at least 80% of the average annual
                              runoff volume of the contributing catchment treated (i.e. 80%
                              hydrological effectiveness) to 50mg/L Total Suspended Solids (TSS) or
                              less, and pH in the range (6.5–8.5).

Litter, Hydrocarbons and   1. Remove gross pollutants and litter.
other contaminants
                           2. Avoid the release of oil or visible sheen to released waters.

                           3. Dispose of waste containing contaminants at authorised facilities.

Waterway Stability and     1. Where measures are required to meet post-construction waterway
flood flow management         stability objectives, these are either installed prior to land disturbance
                              and are integrated with erosion and sediment controls, or equivalent
                              alternative measures are implemented during construction.

                           2. Earthworks and the implementation of erosion and sediment controls
                              are undertaken in ways which ensure flooding characteristics
                              (including stormwater quantity characteristics) external to the
                              development site are not worsened during construction for all events up
                              to and including the 1 in 100 year ARI (1% AEP).




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