Stormwater Management Plan

Good Shepherd Lutheran College                                                                                                            Odyssey Consulting Group
Proposed Unit Development                                                                                                  Conceptual Stormwater Management Plan
Lot 30 on SP170751                                                                                                                               Project No: K4277
115 EUMUNDI NOOSA ROAD, NOOSAVILLE


TABLE OF CONTENTS
1.0     INTRODUCTION .................................................................................................................................................. 1
         1.1     Background ................................................................................................................................................ 1
         1.2     Scope .......................................................................................................................................................... 1
2.0     DESCRIPTION OF SUBJECT SITE ........................................................................................................................... 2
         2.1     Location...................................................................................................................................................... 2
                 2.1.1       Site Topography.......................................................................................................................... 2
                 2.1.2       Vegetation and Land Use ........................................................................................................... 2
         2.2     Proposed Development.............................................................................................................................. 3
3.0     SITE HYDROLOGY AND HYDRAULICS ................................................................................................................... 3
         3.1     Background ................................................................................................................................................ 3
         3.2     Predevelopment ......................................................................................................................................... 3
                 3.2.1       Catchment Definition and Lawful Point of Discharge ................................................................. 3
                 3.2.2       Coefficient of Runoff ................................................................................................................... 3
                 3.2.3       Time of Concentration ................................................................................................................ 4
                 3.2.4       Design Flow Rates ...................................................................................................................... 4
         3.3     Post Development ...................................................................................................................................... 5
                 3.3.1       Catchment Definition and Lawful Point of Discharge ................................................................. 5
                 3.3.2       Coefficient of Runoff ................................................................................................................... 5
                 3.3.3       Time of Concentration ................................................................................................................ 5
                 3.3.4       Design Flow Rates ...................................................................................................................... 5
         3.4     External Catchments .................................................................................................................................. 6
                 3.4.1       Catchment Definition.................................................................................................................. 6
                 3.4.2       Coefficient of Runoff ................................................................................................................... 6
                 3.4.3       Time of Concentration ................................................................................................................ 6
                 3.4.4       Design Flow Rates ...................................................................................................................... 7
                 3.4.5       External Catchment Channel Conveyance .................................................................................. 7
4.0     STORMWATER DETENTION ................................................................................................................................. 7
         4.1     Objective .................................................................................................................................................... 8
         4.2     Hydraulic Model ......................................................................................................................................... 8
         4.3     Detention Volume ...................................................................................................................................... 8
5.0     WATER QUALITY ASSESSMENT ..........................................................................................................................10
         5.1     Background .............................................................................................................................................. 10
         5.2     Water Quality Objectives ......................................................................................................................... 10
         5.3     Construction Phase .................................................................................................................................. 10
                 5.3.1       Common Pollutants .................................................................................................................. 10
                 5.3.2       Performance Criteria ................................................................................................................ 11
                 5.3.3       Sediment and Erosion Controls ................................................................................................. 11
                 5.3.4       Water Quality Monitoring and Inspections .............................................................................. 12
                 5.3.5       Reporting .................................................................................................................................. 12
         5.4     Operational Phase .................................................................................................................................... 12
                 5.4.1       Stormwater Quality Improvement Devices ............................................................................... 12
                 5.4.2       Design Parameters of the Stormwater Quality Improvement System ...................................... 13
                 5.4.3       Post Development Modelling Results - Mitigated .................................................................... 14
6.0     OPERATIONAL PHASE MAINTENANCE REQUIREMENTS ......................................................................................14
         6.1     Bio-retention Basin Maintenance ............................................................................................................ 14
         6.2     Permeable Pavement Maintenance ......................................................................................................... 15
7.0     CONCLUSIONS ...................................................................................................................................................16




K4277-0002                                                                   14 March 2018                                                                          Page ii of iii