Appendix D- Stormwater Management Plan · MCU23/0078

CONTENTS

1.     INTRODUCTION ............................................................................................................................................................................. 1

2.     SITE CHARACTERISTICS ................................................................................................................................................................ 1
2.1 LOCATION AND EXISTING FEATURES ........................................................................................................................................ 1
2.2 PROPOSED DEVELOPMENT .......................................................................................................................................................... 2
2.3 TOPOGRAPHY AND CATCHMENT CHARACTERISTICS ............................................................................................................ 3
       2.3.1         Site A – Western Lot....................................................................................................................................................... 3
       2.3.2         Site B – Eastern Lot......................................................................................................................................................... 3
2.4 EXISTING FLOODING CONDITIONS ............................................................................................................................................ 3

3.     EXISTING AND PROPOSED STORMWATER INFRASTRUCTURE .............................................................................................. 4
3.1 EXISTING INFRASTRUCTURE ....................................................................................................................................................... 4
3.2 PROPOSED STORMWATER DRAINAGE ...................................................................................................................................... 5

4.     STORMWATER QUANTITY ANALYSIS ........................................................................................................................................ 5
4.1 DETAILED HYDRAULIC MODELLING – XP STORM .................................................................................................................... 5
       4.1.1         Existing Scenario Model ................................................................................................................................................ 6
       4.1.2         Results for Existing Scenario ........................................................................................................................................ 6
       4.1.3         XP Storm and Rational Method Comparison ............................................................................................................. 7
       4.1.4         Developed Scenario Model ........................................................................................................................................... 8
       4.1.5         Detention Basin Design ................................................................................................................................................. 9
       4.1.6         Results for Developed Scenario ................................................................................................................................... 9
       4.1.7         Hydraulic Impacts on Downstream Waterway Corridor .........................................................................................11

5.     STORMWATER QUALITY ............................................................................................................................................................12
5.1 CONSTRUCTION PHASE .............................................................................................................................................................12
5.2 OPERATIONAL PHASE.................................................................................................................................................................12
       5.2.1         Pollutants of Concern ..................................................................................................................................................12
       5.2.2         Modelling/Assessment Approach ..............................................................................................................................12
       5.2.3         Meteorological Data ....................................................................................................................................................12
       5.2.4         Source Nodes ................................................................................................................................................................13
       5.2.5         Treatment Methodology .............................................................................................................................................13
       5.2.6         Treatment Nodes .........................................................................................................................................................13
       5.2.7         Proposed Treatment Train - SPEL ..............................................................................................................................15
       5.2.8         Results - SPEL ................................................................................................................................................................15
       5.2.9         Proposed Treatment Train – OceanProtect ..............................................................................................................16
       5.2.10        Results – OceanProtect ................................................................................................................................................17

6.     NOOSA SHIRE COUNCIL CODES ................................................................................................................................................17

7.     SUMMARY ....................................................................................................................................................................................18




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