Stormwater Management Report · MCU19/0008

               Issue          Desired Outcomes




 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 6 – 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

 Where located immediately up-slope of an                       1 in 10 year ARI/10% AEP
 occupied property that would be adversely
 affected by the failure or overtopping of the
 structure

 Culvert Crossing                                                1 in 1 year ARI/63% AEP


Table 7 – SPP Appendix 2: Part 3 Construction Phase – Stormwater Management Design Objectives
for Emergency Spillways on Temporary Sediment Basins

                Drainage Structure                 Anticipated Operation Design Life and Minimum
                                                                Design Storm Event


                                                    <3 Months           3-12 Months        >12 Months

 Emergency spillways         on      temporary     1 in 10 year         1 in 20 year       1 in 50 year
 sediment basins                                  ARI/10% AEP           ARI/5% AEP         ARI/2% AEP

Best practice erosion and sediment controls must be installed to minimise the discharge of sediment
laden runoff during construction and to achieve the objectives outlined in Tables 15-17. This is
discussed in the following section.



4 April 2019                             Stormwater Management Report                                   12
S18-030                                     22 Arakoon Crescent,