Storm Water management plan · MCU12/0133.03

Noosa Council documents


                  Bligh Tanner Consulting Engineers                                                                                                   Page ii
                  Noosa Flexi Learning Centre Stormwater Management Plan
                  August 2012



                  TABLE OF CONTENTS

                  EXECUTIVE SUMMARY ...................................................................................................... IV
                  GLOSSARY .......................................................................................................................... V
                  1 INTRODUCTION ............................................................................................................. 1
                   1.1 Locality Plan ............................................................................................................ 2
                   1.2 Site Characteristics................................................................................................. 2
                   1.3 Proposed Land Uses .............................................................................................. 3
                   1.4 Location Conditions ............................................................................................... 3
                   1.5 Rainfall zone ............................................................................................................ 3
                   1.6 Soil Category ........................................................................................................... 3
                  2 DESIGN OBJECTIVES ................................................................................................... 5
                   2.1 Stormwater Treatment Objectives ......................................................................... 5
                   2.2 Hydrologic Objectives ............................................................................................ 6
                   2.3 Water Savings Targets ........................................................................................... 6
                   2.4 Construction Phase Objectives ............................................................................. 7
                     Erosion Hazard Assessment ........................................................................................... 7
                  3 STRATEGY DESCRIPTION AND PLAN ........................................................................ 8
                   3.1 Erosion and Sediment Control Strategy................................................................ 9
                   3.2 Stormwater Treatment Strategy ............................................................................. 9
                  4 STORMWATER QUALITY ASSESSMENT................................................................... 11
                  5 HYDROLOGIC ASSESSMENT ..................................................................................... 14
                   5.1 Flooding of the site ............................................................................................... 14
                   5.2 Flooding impacts downstream of the site ........................................................... 14
                   5.3 Frequent flow impacts downstream of the site ................................................... 16
                  6 IMPLEMENTATION ...................................................................................................... 17
                   6.1 Construction.......................................................................................................... 17
                  7 CONCLUSION .............................................................................................................. 18
                  8 REFERENCES .............................................................................................................. 19

                  List of Figures
                  Figure 1 Locality Plan showing the site in relation to relevant receiving environments ........... 2
                  Figure 2 Site plan showing relevant features of the stormwater strategy .............................. 10
                  Figure 3 MUSIC model schematic........................................................................................ 12
                  Figure 4: Comparison of runoff volumes and pollutant loads, which shows that the mitigated
                  pollutant loads are close to existing levels and well below a conventional ‘best-practice’
                  approach (note logarithmic scale). Actual values are presented in Table 6. ........................ 12
                  Figure 5 Catchment boundary and overland flow paths ....................................................... 14
                  Figure 6 Comparison of pre and post developed peak flows (without mitigation). The increase
                  in peak flow for the Q100 is about 140 litres per second. ..................................................... 15
                  Figure 7: Comparison of pre and post development flow frequency showing that the
                  proposed development avoids increasing the wetness of the downstream ecosystem......... 16

                  List of Tables
                  Table 1 Key site information.................................................................................................. 1
                  Table 2: Soil Properties estimated using the Atlas of Australian Soils .................................... 3
                  Table 3 How the proposal responds to the Noosa Plan.......................................................... 5
                  Table 4 Values used in erosion hazard estimation ................................................................. 7



                                                                                                                                Print Date: 2 March 2020, 2:19 PM