Appeal 26-042 - Lodgement Documents · MCU10/2113.03

                                34.5.3.    Temporary vehicular crossings of waterways must be designed and
                                           constructed to convey flows and remain stable for all rainfall events up
                                           to the 1 in 10-year average recurrence interval (ARI) event of critical
                                           duration.
                        34.6. Ensure clean stormwater is diverted or managed around or through the site without
                              increasing the concentration of total suspended solids or other contaminants in
                              the flow and without causing erosion (on site or off site). If it is not feasible to divert
                              all areas discharging clean stormwater around or through the site, manage the
                              clean stormwater runoff as for contaminated stormwater runoff, and ensure that
                              sediment basins are sized to accommodate the additional volume of runoff (See
                              E&SC Advice Note 3);
                        34.7. Ensure sheet flows of stormwater are managed such that sheet and rill erosion is
                              prevented or minimised.
                        34.8. Ensure that all concentrated stormwater flows including drainage lines, diversion
                              drains, channels and batter chutes are managed onto, through, and at release
                              points from the site in all rain events up to and including the average recurrence
                              interval (ARI) event of 1 in 2 year ARI without causing water contamination, sheet,
                              rill or gully erosion, sedimentation, or damage to structures or property.
                        34.9. Ensure measures have been implemented such that the runoff from all disturbed
                              areas flows to a sediment basin or basins. Where it is not feasible to divert runoff
                              from small disturbed areas of the site to a sediment basin, implement
                              compensatory erosion and sediment controls (See E&SC Advice Note 4).
                        34.10. Ensure each sediment basin has the capacity to treat flows to current best
                               practice standards (see E&SC Advice Note 5) and as a minimum to contain all
                               the stormwater runoff from the 80th percentile 5 day rainfall depth and store 2
                               months sediment from the receiving catchment, as determined using the Revised
                               Universal Soil Loss Equation.
                        34.11. Ensure sediment basins are maintained with sufficient storage capacity to
                               capture and treat the runoff for the design rainfall depth or event. Where
                               sediment basins are proposed to be oversized for storage of captured water for
                               re-use, install survey markers in each such basin to indicate the level that water
                               within the basin must be lowered to, in order to meet the storage capacity
                               specified in the above requirement.
                        34.12. Ensure sediment basins are dewatered as soon as practicable after each rainfall
                               event.
                        34.13. Ensure stormwater captured in sediment basins is treated prior to discharge to
                               minimise the volume and concentration of contaminants released from site,
                               having due regard to forecast rainfall (See E&SC Advice Note 6).
                        34.14. Ensure sediment basins and associated structures such as inlets, outlets and
                               spillways are structurally sound for 10 year ARI rainfall event, under normal
                               circumstances and for 100 year ARI rainfall event, if failure of the basin poses a
                               threat to downstream dwellings or public safety.
                        34.15. Ensure accumulated sediment from basins and other controls is removed and
                               disposed of appropriately without causing water contamination.
                        34.16. Ensure sediment does not leave the site on the tyres of vehicles.
                        General
                 35.    A suitably qualified Registered Professional Engineer must prepare engineering
                        drawings and specifications for all engineering works, which must be submitted in
                        conjunction with an application for a Development Permit for Operational Works.



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Document Set ID: 24928702
Version: 6, Version Date: 09/07/2026