Hydraulic Assessment 29 August 2024

  3.1.1       Modelling Parameters
A hydrologic analysis of the Site and contributing catchments has been undertaken to determine the pre- and post-development peak
discharges. Key hydrologic model details are provided in Table 3.2.

TABLE 3.2: KEY MODELLING PARAMETERS – HYDROLOGY


 Parameter                            Details                                         Basis / Comments

 Software                             WBNM                                            -

 Approach                             ARR 2019 Methodology                            -

 Pervious Initial and Continuing
                                      51mm and 3mm/hr                                 ARR Data Hub
 Losses
                                                                                      Lat: -26.383
 Temporal Patterns                    East Coast North (ECNorth)                      Long: 152.839
                                                                                      Median pre-burst depths have been subtracted
 Pre-Burst                            Median                                          from the total storm initial loss.

                                                                                      BOM Rainfall IFD Data System
 IFD                                  -                                               Lat: -26.383
                                                                                      Long: 152.839


  3.1.2       Rational Method Validation
The peak flow estimates from the hydrologic model were validated using the Rational Method at the catchment outlet. The difference
between peak flows was 0.1m³/s (3%), indicating that the WBNM model is suitable for use and there are no gross errors. As such the model
is considered suitable for this assessment.

TABLE 3.3: PEAK DISCHARGE COMPARISON – EXISTING CASE RATIONAL METHOD & WBNM


                                                                                1% AEP

 WBNM (m3/s)                                                                    3.7

 Rational (m3/s)                                                                3.6

 Difference (m3/s)                                                              0.1

 Difference (%)                                                                 3




38 BARINA COURT, POMONA I BBNE00000_0020-REP-001-0                                                                                    7