5179Flood Report_REV_3

                                                                                                                           Callaghan & Toth




CONTENTS
1.0    INTRODUCTION .................................................................................................................... 4
Figure 1.2 Existing Site Topography And Relevant Catchment Boundaries ............................. 5
Figure 1.3 Proposed Development Layout And Relevant Catchment Boundaries ..................... 5
2.0    FLOOD IMMUNITY ................................................................................................................. 6
3.0 STORMWATER DETENTION REQUIREMENT ............................................................ 7
3.1 Broad-Brush Estimate Of Required Detention Volume ....................................................... 7
3.2 Hydrologic Model Set Up .................................................................................................... 7
Table 1 Predicted Peak Outflow Rates (m3/sec) – Sanity Check................................................ 8
3.3 Model Determination Of The Required Detention Volume ................................................. 9
Table 2: Required Detention Volumes ....................................................................................... 9
3.4 Provision of Required Detention Volume ............................................................................ 9
     Table 3 Required Detention Water Levels.......................................................................... 9
4.0    SUMMARY ........................................................................................................................... 11
APPENDIX 1     - Reconfiguration of a Lot Layout plans .................................................................... A
APPENDIX 2     - FLOOD CALCULATIONS ..................................................................................... D



LIST OF FIGURES

Figure 1.1                      Site Location Plan……………………………………………………………..........4
Figure 3.1                      URBS Model of the Pre-Development Catchment Condition……….………….7
Figure 3.2                      URBS Model Of the Post-Development Catchment Condition……….……......8
Figure 3.3                      Proposed Stormwater Detention Facilities………………………………..…......10




LIST OF TABLES

Table 1              Predicted Peak Outflow Rates……………………..……………. …………………………8
Table 2              Required Detention Volumes …………………….……………. …………………………..9




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2035 2 Pearsons Road – Flood Study – Revision 3                                                                    April 2021