SDL Offsets in the Lower Murray NSW: Locks 8 and 9 Weir Pool Manipulation Carrs, Capitts and Bunberoo Creeks Connectivity Frenchmans Creek Fish Passage at August 2015
Total Page:16
File Type:pdf, Size:1020Kb
DISCLAIMER: This is a preliminary business case, used to inform decision-making by the Murray- Darling Basin Ministerial Council and Basin Officials’ Committee on sustainable diversion limit adjustment mechanism projects. The document represents the Business case for SDL offsets in the Lower Murray NSW: Locks 8 and 9 weir pool manipulation Carrs, Capitts and Bunberoo Creeks connectivity Frenchmans Creek fish passage at August 2015. The NSW Department of Industry is currently developing project summary documents that will summarise project details, and will be progressively published on the Department of Industry website. Detailed costings and personal information has been redacted from the original business case to protect privacy and future tenders that will be undertaken to deliver these projects. Business case for SDL offsets in the Lower Murray NSW: Locks 8 and 9 weir pool manipulation Carrs, Capitts and Bunberoo Creeks connectivity Frenchmans Creek fish passage Final business case August 2015 Document review and authorisation Doc. Final/Draft Date Authors Reviewed by Quality check Release approved Issued to Copies Version by 1.0 Draft 30/03/15 1e 2.0 Draft 9/04/15 1e - for distribution to SC members 3.0 Final draft 17/04/15 1e 4.0 Final draft v2 4/06/15 1e Notes: * Ecological Associates ** Alluvium Published by the NSW Department of Primary Industries, DPI Water Business case for SDL offsets in the Lower Murray NSW: Locks 8 and 9 weir pool manipulation. Carrs, Capitts and Bunberoo Creeks connectivity. Frenchmans Creek fish passage. First published August 2015 ISBN number – get this by filling in a request to More information www.dpi.nsw.gov.au Acknowledgments This report has been prepared by RMCG, Alluvium and Ecological Associates. Front cover: Bunberoo Creek (James Val, NSW OEH) [Insert Reference number] © State of New South Wales through the Department of Trade and Investment, Regional Infrastructure and Services, 2015. You may copy, distribute and otherwise freely deal with this publication for any purpose, provided that you attribute the NSW Department of Primary Industries as the owner. Disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing (August 2015). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of the Department of Primary Industries or the user’s independent adviser. Business case for SDL offsets in the Lower Murray Final: August 2015 Contents Abbreviations 1 Executive Summary i ES1. The location ............................................................................................................................... i ES2. The proposal ..............................................................................................................................ii ES.3 Works and costs ....................................................................................................................... iii ES.4 Risk management ..................................................................................................................... v ES5. Governance ..............................................................................................................................vi 1 Introduction 1 1.1 Overview .................................................................................................................................... 1 1.2 Eligibility ..................................................................................................................................... 1 2 Project details 2 2.1 Locality ....................................................................................................................................... 2 2.2 Significance ............................................................................................................................... 3 2.3 Proposed works package .......................................................................................................... 4 2.3.1 Component 1: Locks 8 and 9 weir pool manipulation 4 2.3.2 Component 2: Carrs, Capitts and Bunberoo Creeks system connectivity 5 2.3.3 Component 3: Frenchmans Creek fish passage 5 2.3.4 Overview of site hydrology 6 2.4 Summary of costs and proposed schedule ............................................................................... 8 2.4.1 Project costs 8 2.4.2 Project schedule 8 2.5 Proponent and proposed implementing entity ........................................................................... 8 3 Values of the site 9 3.1 Ecological values overview ........................................................................................................ 9 3.2 Listed flora and fauna ................................................................................................................ 9 3.2.1 Flora 9 3.2.2 Fauna 9 3.3 Aquatic environments .............................................................................................................. 13 3.3.1 Overview of significant areas 13 3.3.2 Water dependent vegetation communities 14 3.3.3 Water regime classes 15 3.3.4 Ecosystem functions 17 3.4 Social and economic values .................................................................................................... 18 3.5 Cultural values ......................................................................................................................... 18 3.6 Threats to values ..................................................................................................................... 19 4 Ecological objectives and targets 21 4.1 Overarching goal ..................................................................................................................... 21 4.2 Ecological objectives and targets ............................................................................................ 21 NSW DPI Water, August 2015 Business case for SDL offsets in the Lower Murray Final: August 2015 4.2.1 Aquatic macrophytes 21 4.2.2 Floodplain vegetation 22 4.2.3 Organic matter processing and supply 23 4.2.4 Biofilms 23 4.2.5 Waterbird abundance and foraging 24 4.2.6 Small-bodied native fish 24 4.2.7 Large-bodied native fish 26 4.3 Summary ecological objectives and targets ............................................................................ 29 4.4 Interdependencies ................................................................................................................... 34 4.5 Contribution to Basin Plan objectives ...................................................................................... 37 5 Anticipated ecological outcomes 39 5.1 Current condition ..................................................................................................................... 39 5.2 Past water management activities ........................................................................................... 40 5.3 Expected benefits .................................................................................................................... 41 5.4 Monitoring, evaluation and reporting plans .............................................................................. 45 6 Potential adverse ecological impacts 46 6.1 Overview of risk assessment ................................................................................................... 46 6.1.1 Risk assessment methodology 46 6.2 Locks 8 and 9, weir pool manipulation ecological risks ........................................................... 47 6.3 CCB Creeks connectivity ecological risks ............................................................................... 49 6.4 Frenchmans Creek fish passage ecological risks ................................................................... 51 7 Current hydrology and proposed changes 53 7.1 Project area description ........................................................................................................... 53 7.1.1 New South Wales floodplain from Lock 10 to Frenchmans Creek 53 7.1.2 Darling Anabranch 54 7.1.3 Lake Victoria floodplain 54 7.1.4 Wallpolla Island 55 7.1.5 Mulcra Island and Big Paddock 56 7.2 Hydrological context ................................................................................................................ 57 7.3 Hydraulic effects of the weirs ................................................................................................... 59 7.3.1 Water level variability 59 7.3.2 Velocity 60 7.4 Proposed hydrology ................................................................................................................. 61 7.4.1 Locks 8 and 9 weir pools 61 7.4.2 Carrs, Capitts and Bunberoo Creeks connectivity 65 7.5 Water use ................................................................................................................................ 66 7.5.1 Locks 8 and 9 weir pools net water use 66 7.5.2 Carrs, Capitts and Bunberoo Creeks connectivity net water use 67 8 Environmental water requirements 69 8.1 Water requirements ................................................................................................................. 69 8.2 Hydrological gaps to be addressed ......................................................................................... 69 NSW DPI Water, August 2015 Business case for SDL offsets in the Lower Murray Final: August 2015 9 Operating regime 71 9.1 Overview .................................................................................................................................