SUPERSEDED Decision Notice OPW25 0042 · OPW25/0042

                                       b)   From all disturbed areas of the site to sediment basin(s) without causing
                                            erosion
                      c.      Minimise sediment released from the site.
                              i.       Prior to each rainfall event ensure concentrated stormwater flow paths are
                                       provided with capacity in accordance with IECA (2008) Table 4.3.1 and are
                                       structurally stable in all rainfall events for the following sources:
                                       a)   Each basin is sized and operated in accordance with either a Type-A or
                                            Type-B sediment basin as documented in IECA (2008) Appendix B (June
                                            2018).
                                       b)   Each basin is to be provided with an automated system of flocculent dosing
                                            and a suitable supply of flocculent/coagulant, with the type of
                                            flocculent/coagulant determined based on Chemical Coagulants and
                                            Flocculants Fact Sheet (IECA, 2018).
                                       c)   Markers are provided within each basin indicating the maximum sediment
                                            storage level and any additional water storage capacity for water reuse.
                                       d)   During discharge from the primary outlet system, the concentration of total
                                            suspended solids (“TSS”) discharged does not exceed 50mg/L and that pH
                                            is within the range of 6.5-8.5 unless entering a naturally acidic environment.
                              ii.      Install and maintain additional sediment control measures within the site, as
                                       necessary to maximise sediment capture.
                              iii.     Minimise the tracking of dirt from the site onto roadways. Ensure that all dirt on
                                       roadways caused by vehicles leaving the site is removed without causing water
                                       contamination, prior to rainfall and at least at the end of each work day.
               40.    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% AEP (1 in 100 year ARI) event.
               41.    Drainage paths must be regularly inspected to ensure the sediment fences/measures are not
                      being bypassed as a result of sediment build up. Sediment laden runoff must be prevented
                      from leaving the subject site and entering neighbouring properties and/or stormwater
                      systems.
               42.    Soil exposure must be limited on the site to a distance of no more than 2m beyond the extent
                      of earthworks shown on the approved plans except where the exposed soil is effectively
                      stabilised without delay and prior to rainfall occurring.
               43.    A log book for the Erosion and Sediment Control measures and inspections must be
                      maintained by the site manager and made readily available to Council when requested. The
                      supervising engineer must verify and endorsed the E&SC measures upon their installation,
                      and periodically check these measures and the log book during construction and the
                      stabilisation stages. Any defects in erosion and sediment control devices, such as sediment
                      fences, are to be inspected and documented. Upon Inspection, the contractor is to determine
                      whether the device should be replaced or repaired. Documentation is to include how the
                      damage was caused and what measures can be implemented to reduce the possibility of
                      repeat occurrences. Any damage to either permanent or temporary water quality control
                      structures or devices is to be immediately rectified at the contractor’s expense.
                      The effectiveness of the erosion and sediment control devices must be monitored. All ESC
                      measures are to be inspected:
                      a.      at least daily (when work is occurring on site) or weekly (when work is not occurring on
                              site); or
                      b.      within 24 hours of expected rain; or




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Document Set ID: 24023937
Version: 2, Version Date: 12/08/2025