Revised Stormwater Management Plan

                              STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust                 Location: Taylor Court, Cooroy

                                       CONTENTS

1.0 INTRODUCTION                                                                       1

2.0 SITE DESCRIPTION                                                                   1

    2.1    Site Location                                                               1

    2.2    Previous Land-use, Topography and Drainage                                  2

    2.3    Proposed Land-use                                                           2

3.0 WATER QUALITY AND TREATMENT OBJECTIVES                                             2

    3.1    Water Quality Objectives                                                    3

    3.2    Area of Treatment                                                           3

    3.3    Non-treatment Areas                                                         3

4.0 WATER QUALITY MODELLING ASSESSMENT/APPROACH                                        4

    4.1    Scenario Methodology                                                        4

    4.2    MUSIC Model Parameters                                                      5

    4.3    Land Use/Source Node Areas.                                                 5

    4.4    Proposed Stormwater Treatment Train                                         6

    4.5    Pollutant Reduction Results                                                 6

5.0 MAINTENANCE PERIOD                                                                 7

    5.1 Bioretention Basin                                                             7
   5.1.1 Maintenance During ‘Construction Phase’                                       7

6.0 STORMWATER QUANTITY                                                                8

    6.1    Stormwater Quantity Management                                              8

    6.2    Hydrology (XP-RAFTS)                                                        8

    6.3 XP-RAFTS Data                                                                  8
   6.3.1 Model Scenarios                                                               8
   6.3.2    Rainfall Intensities                                                       8
   6.3.3    Existing and Proposed Development Areas                                    9
   6.3.4    Initial and Continuing Losses                                              9
   6.3.5    Pervious and Impervious Areas                                              9
   6.3.6    Manning’s Values                                                          10
   6.3.7    Catchment Slope                                                           10
   6.3.8    Storm Durations                                                           10