MCU16/0012 Attach B Engineering report & SMP

                                              3 Garnet Street Cooroy, QLD 4563
                                              State Planning Policy December 2014 - Healthy Waters (DERM)
                                                 Performance Outcome Criteria and Acceptable Outcomes


                  Performance outcomes                                Acceptable outcomes                                         Solution
                                                        bonds, headworks charges or levies.




    Table A: Construction phase—stormwater management design objectives
    Application
    Applies to all climatic regions.


         Issue                                                                        Design Objectives
                           Temporary                     1. Design life and design storm for temporary drainage works:
Drainage Control
                           drainage                      • Disturbed area open for <12 months—1 in 2-year ARI event
                           works                         • Disturbed area open for 12–24 months—1 in 5-year ARI event
                                                         • Disturbed area open for > 24 months—1 in 10-year ARI event
                                                         2. Design capacity excludes minimum 150 mm freeboard
                                                         3. Temporary culvert crossing—minimum 1 in 1-year ARI hydraulic capacity
                           Erosion                       1. Minimise exposure of disturbed soils at any time
Erosion Control
                           control measures              2. Divert water run-off from undisturbed areas around disturbed areas
                                                         3. Determine the erosion risk rating using local rainfall erosivity, rainfall depth, soil-loss rate or
                                                         other acceptable methods
                                                         4. Implement erosion control methods corresponding to identified erosion risk rating
                           Sediment control              1. Determine appropriate sediment control measures using:
Sediment Control
                           measures                      • potential soil loss rate, or
                                                         • monthly erosivity, or
                                                         • average monthly rainfall
                                                         2. Collect and drain stormwater from disturbed soils to sediment basin for design storm event:
                                                         • design storm for sediment basin sizing is 80th% five-day event or similar
                           Design storm for              3. Site discharge during sediment basin dewatering:
                           sediment                      • TSS < 50 mg/L TSS, and