ECM_22343539_v1_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




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Document Set ID: 22343539
Version: 1, Version Date: 16/03/2023