Stormwater Mgmt Plan

SC-8407 – 45 Maple Street, Cooroy                                                                                                               iii




                                                 TABLE OF CONTENTS
1.0       Introduction ................................................................................................................. 1
   1.1        Background ...............................................................................................................1
   1.2        Scope ........................................................................................................................1
   1.3        Existing Topography .................................................................................................1
   1.4        Proposed Development ............................................................................................1
2.0       Existing Drainage Regime .......................................................................................... 3
   2.1        Subject Site ...............................................................................................................3
3.0       Stormwater Quality Management .............................................................................. 4
   3.1        Background ...............................................................................................................4
   3.2        Construction Phase ..................................................................................................4
   3.3        Operational Phase ....................................................................................................6
      3.3.1       Water Quality Objectives ......................................................................................6
4.0       Stormwater Quantity Management ............................................................................ 7
      4.1         Background ..........................................................................................................7
      4.2         Methodology .........................................................................................................7
      4.3.2       Catchment Areas ..................................................................................................8
      4.3.3       Roughness Coefficients .......................................................................................8
      4.3.4       Storm Events ........................................................................................................8
      4.3.5       Outlet Condition ....................................................................................................9
      4.3.6       On-Site Detention .................................................................................................9
   4.4        Modelling Results ...................................................................................................10
5.0       Flood Hazard Overlay and External Catchment ..................................................... 11
6.0       Conclusions ............................................................................................................... 11
APPENDIX A – CONCEPT STORMWATER MANAGEMENT PLAN AND ........................... 12
DETAIL & CONTOUR SURVEY ............................................................................................. 12
APPENDIX B – XP STORM MODELLING RESULTS ............................................................ 13