Stormwater Management Report

          Issue             Desired Outcomes




 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).


Table 3 – SPP Appendix 2: Part 2 Construction Phase – Stormwater Management Design Objectives
for Temporary Drainage Works

 Temporary Drainage Works                       Anticipated Operation Design Life and Minimum
                                                             Design Storm Event


                                                 <12 Months          12-24 Months          >24 Months

 Drainage Structure                              1 in 2 year          1 in 5 year          1 in 10 year
                                                ARI/39% AEP          ARI/18% AEP          ARI/10% AEP




                                                                                                           4