Site Based Stormwater Managment Plan

                                                                                             20169 - SBSMP/2
                                                                                                          Page 2




                                           Table of Contents
1     INTRODUCTION ............................................................................................ 3
2     EXISTING SITE CONDITIONS .............................................................................. 4
  2.1    The Site ................................................................................................ 4
  2.2    Surrounding Area ...................................................................................... 4
3     PROPOSED DEVELOPMENT ............................................................................... 5
4     EXISTING DRAINAGE PATTERNS ......................................................................... 6
  4.1    Existing Infrastructure ............................................................................... 6
  4.2    Existing Drainage Patterns ........................................................................... 7
  4.3    Lawful Point of Discharge............................................................................ 7
5     STORMWATER QUANTITY................................................................................. 9
  5.1    Rational Method Assessment ........................................................................ 9
    5.1.1     Design Storms ....................................................................................9
    5.1.2     Rainfall Intensity ................................................................................9
    5.1.3     Times of Concentration .........................................................................9
    5.1.4     Runoff Coefficients ..............................................................................9
    5.1.5     Peak Flows ...................................................................................... 10
  5.2    Proposed Drainage Patterns ....................................................................... 10
  5.3    Downstream Pipe Infrastructure Considerations ............................................... 11
  5.4    XPSTORM Modelling ................................................................................. 11
    5.4.1     Intensity Frequency Distribution ............................................................ 11
    5.4.2     Initial and Continuing Losses ................................................................. 11
    5.4.3     On-site Detention .............................................................................. 12
    5.4.4     Comparison of Peak Flows at Lawful Point of Discharge ................................. 12
6     STORMWATER QUALITY ................................................................................ 14
  6.1    State Planning Policy Assessment ................................................................ 14
  6.2    Construction Phase ................................................................................. 14
  6.3    Operational Phase .................................................................................. 16
    6.3.1     Sources of Contaminants ..................................................................... 16
    6.3.2     Proposed Treatment Train ................................................................... 17
    6.3.3     Pollutant Export Modelling ................................................................... 17
    6.3.4     MUSIC Modelling Parameters ................................................................. 18
    6.3.5     MUSIC Modeling Results ....................................................................... 18
7     FLOODING ................................................................................................ 20
8     CONCLUSION ............................................................................................. 21
Appendix A DETAILED SITE SURVEY PLAN ................................................................. 22
Appendix B PROPOSED DEVELOPMENT PLANS ............................................................ 23
Appendix C NOOSA COUNCIL INTERACTIVE MAPPING DATA ............................................ 24
Appendix D NSC WATER QUALITY AND DRAINAGE CODE ................................................ 25
Appendix E STORMWATER QUANTITY CALCULATIONS................................................... 26
Appendix F CONCEPT SITE LEVELS AND DRAINAGE PLAN ............................................... 27
Appendix G BOM IFD DATA .................................................................................. 28
Appendix H XPSTORM PRE DEVELOPMENT RESULTS ..................................................... 29
Appendix I XPSTORM POST DEVELOPMENT RESULTS.................................................... 30
Appendix J XPSTORM POST DEVELOPMENT MITIGATED RESULTS ...................................... 31
Appendix K STORMWATER QUALITY AND MAINTENANCE GUIDELINES ................................. 32
Appendix L NSC FLOOD HAZARD OVERLAY MAP .......................................................... 33




Site Based Stormwater Management Plan
Proposed Townhouse Development at 99, 101 & 105 Eumundi Noosa Road, Noosaville