Port Waterways Water Quality Improvement Plan Port Waterways Water Quality Improvement Plan Port Waterways Water Quality Improvement Plan Author: Peter Pfennig Acknowledgements: Eco Management Services: Paul Manning EPA: Peter Christy, Sam Gaylard, Dr Clive Jenkins, Dr Shaun Thomas, Bettina Venner Flinders Ports: Greg Pearce, Terry Vickery Water Data Services: Bruce Nicholson SA Water: Tim Kildae Department of Water, Land and Biodiversity: Tim Bradford Department of Transport, Energy and Infrastructure: Roger Galbraith Some of the materials in this report is drawn from a project by Arup Pty Ltd and Eco Management Services Pty Ltd. Funding and resources for this project were provided by the Australian Government Coastal Catchment Initiative. For further information please contact: Information Officer Environment Protection Authority GPO Box 2607 Adelaide SA 5001 Telephone: (08) 8204 2004 Facsimile: (08) 8124 4670 Free call (country): 1800 623 445 Website: <www.epa.sa.gov.au> E-mail: <[email protected]> ISBN 978-1-921125-66-9 May 2008 Disclaimer The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment, Water, Heritage and the Arts. While all reasonable efforts have been made to ensure that the contents of this publication are factually correct, the Commonwealth does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication. © Environment Protection Authority This document may be reproduced in whole or part for the purpose of study or training, subject to the inclusion of an acknowledgment of the source and to its not being used for commercial purposes or sale. Reproduction for purposes other than those given above requires the prior written permission of the Environment Protection Authority. Printed on recycled paper TABLE OF CONTENTS Summary 1 1 Introduction 9 1.1 The Port waterways and its catchment 9 1.2 Nutrients and the ecological condition of the Port waterways 9 1.3 The Water Quality Improvement Plan 9 1.4 Environmental values of the Port waterways 13 1.5 Nutrient reduction to date 13 1.6 Environmental flow management in the Port waterways 14 1.7 Consultation processes used in developing the plan 14 1.8 Ongoing involvement with the Adelaide and Mount Lofty Ranges Natural Resources Management Board 15 1.9 Ongoing involvement with the Adelaide Dolphin Sanctuary 15 2 Water quality—nutrient objectives and loads 17 2.1 Summary of key water quality issues 17 2.2 Environmental values of the Port waterways 21 2.3 General water quality status prior to the WQIP 25 2.4 Water quality objectives (nutrients) 25 2.5 Existing programs resulting in nitrogen and phosphorus load reduction improvements to date 29 2.6 Nutrient load reduction required to achieve the water quality objectives 31 2.7 Load reduction targets/load allocations 38 2.8 Margin of safety 39 3 Implementation and research—management measures and control actions 41 3.1 Current nutrient load reduction programs and actions 41 3.2 River flow objectives 59 3.3 Growth management and addressing impacts of climate change 59 3.4 Use of market-based instruments 61 3.5 Institutional and organisational reforms 61 3.6 Regulatory reforms to support improved water quality and environmental flows 62 3.7 Priority WQIP research and development activities 62 3.8 Adaptive management for the Port Waterways WQIP 63 4 Monitoring the WQIP implementation 69 4.1 Introduction 69 4.2 Water quality modelling strategy 69 4.3 Water quality monitoring programs 70 4.4 Monitoring implementation of the WQIP 70 5 Reporting and review 72 5.1 Introduction 72 5.2 WQIP reporting and review process 72 References 75 Glossary 76 Appendix A: Statutory capacity to implement the Port Waterways Water Quality Improvement Plan 80 Appendix B: Programs and funding for the implementation of the Port Waterways Water Quality Improvement Plan 89 Appendix C: Reasonable assurance statement for the Port Waterways Water Quality Improvement Plan 96 Appendix D: WQIP for Port Adelaide’s waterway 102 Appendix E: Water flows 112 Appendix F: Model output of nutrient load reductions for the Port waterways 126 Appendix G: Nutrient Reduction Options Discussion Paper, November 2005 187 iv LIST OF FIGURES Figure 1.1 Port waterways location and catchments 10 Figure 1.2 Summary of the water quality management framework 11 Figure 2.1 Key water quality issues in the Port waterways study area 18 Figure 2.2 Main features and segments for protection of water quality 22 Figure 2.3 Water quality classification 24 Figure 2.4 Combined summer (Nov to Mar) Nutrient Loads from Port Adelaide & Bolivar WWTPs 30 Figure 2.5 Bolivar peak monthly nutrient marine loads 30 Figure 2.6 Modelled Port waterways chlorophyll a concentrations 1998 and 2004 34 Figure 2.7 Modelled Port waterways total nitrogen concentrations 1998 and 2004 35 Figure 2.8 Modelled Port waterways ammonia concentrations 1998 and 2004 36 Figure 2.9 Modelled winter chlorophyll a concentrations adjacent to Swan Alley as nutrients in the Port Waterways reduce 37 Figure 2.10 Modelled winter chlorophyll a concentrations at the North Arm as nutrients in the Port Waterways reduce 37 Figure 3.1 Comparison of annual TN and TP loads 1995–2015 57 Figure 3.2 Comparison of annual TN loads from major sources 1995–2015 57 Figure 3.3 Comparison of annual TN loads from small sources 1995–2010 58 Figure 3.4 Comparison of annual TP loads from major sources 1995–2015 58 Figure 3.5 Comparison of annual TP loads from small sources 2005–2010 59 Figure 3.6 Adaptive management framework as it applies to nutrients in the Port waterways 65 Figure 4.1 EPA ambient water quality monitoring program locations in the Port waterways 71 Figure E1 Watercress model layout 118 Figure E2 Present day non-urbanised flows (ML/year) 120 Figure E3 Pre-European flows (ML/year) 121 Figure E4 Estimated pre-European annual flows to Barker Inlet 124 Figure E5 % time exceedence for estimated pre-European daily flows to Barker Inlet 125 Figure F1 Differences in modelled total phosphorus at three sites along the Port River following reductions in nutrient discharges between 1998 and 2004 131 Figure F2 Differences in modelled total ammonium at three sites along the Port River following reductions in nutrient discharges between 1998 and 2004 132 Figure F3 Differences in modelled total nitrogen at three sites in central Barker inlet following reductions in nutrient discharges between 1998 and 2004 133 Figure F4 Differences in modelled total ammonium at three sites in central Barker inlet following reductions in nutrient discharges between 1998 and 2004 134 Figure F5 Differences in modelled total phosphorus at three sites in central Barker inlet following reductions in nutrient discharges between 1998 and 2004 135 Figure F6 Differences in modelled total phosphorus at three sites in the region of northern Barker inlet following reductions in nutrient discharges between 1998 and 2004 136 Figure F7 Differences in modelled total nitrogen at three sites in the region of northern Barker inlet following reductions in nutrient discharges between 1998 and 2004 137 v Figure F8 Differences in modelled total ammonium at three sites in the region of northern Barker inlet following reductions in nutrient discharges between 1998 and 2004 138 Figure F9 Distribution of total phosphorus in the Port waterways during a spring high tide— normal 2004 discharges of nutrients from the Penrice facility and the Bolivar WWTP 139 Figure F10 Distribution of total phosphorus in the Port waterways during a spring low tide— normal 2004 discharges of nutrients from the Penrice facility and the Bolivar WWTP 140 Figure F11 Distribution of total phosphorus in the Port waterways during a neap ebbing tide— normal 2004 discharges of nutrients from the Penrice facility and the Bolivar WWTP 141 Figure F12 Distribution of total phosphorus in the Port waterways influenced by a north wind— normal 2004 discharges of nutrients from the Penrice facility and the Bolivar WWTP 142 Figure F13 Distribution of total nitrogen in the Port waterways during a neap ebbing tide—based on 1998 discharges of nutrients from the Penrice facility, and the Bolivar and Port Adelaide WWTPs 143 Figure F14 Distribution of total nitrogen in the Port waterways during a neap ebbing tide—normal 2004 discharges of nutrients from the Penrice facility and the Bolivar WWTP 144 Figure F15 Distribution of total ammonium in the Port waterways during a neap ebbing tide— based on 1998 discharges of nutrients from the Penrice facility, and the Bolivar and Port Adelaide WWTPs 145 Figure F16 Distribution of total ammonium in the Port waterways during a neap ebbing tide— normal 2004 discharges of nutrients from the Penrice facility and the Bolivar WWTP 146 Figure F17 Distribution of total phosphorus in the Port waterways during a neap ebbing tide— based on 1998 discharges of nutrients from the Penrice facility, and the Bolivar and Port Adelaide WWTPs 147 Figure F18 Distribution of chlorophyll a in the Port waterways during a neap ebbing tide—based on 1998 discharges of nutrients from the Penrice facility, and the Bolivar and Port Adelaide WWTPs 148 Figure F19 Distribution of chlorophyll a in the Port waterways during a neap ebbing tide—normal 2004 discharges of nutrients from the Penrice facility and the Bolivar WWTP 149 Figure