Future Water Planning Enlarged Cotter Dam Fish Management
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FFUUTTUURREE WWAATTEERR PPLLAANNNNIINNGG EENNLLAARRGGEEDD CCOOTTTTEERR DDAAMM FFIISSHH MMAANNAAGGEEMMEENNTT PPLLAANN ((VVEERRSSIIOONN 11)) 1122 FFEEBBRRUUAARRYY 22000099 Prepared For: Prepared By: INFRASTRUCTURE DEVELOPMENT BRANCH WATER DIVISION 12 HOSKINS STREET MITCHELL ACT 2911 ActewAGL Distribution ABN 76 670 568 688 a partnership of ACTEW Distribution Ltd ABN 83 073 025 224 and AGL Gas Company (ACT) Pty Ltd ABN 24 008 552 663. CERTIFICATE OF APPROVAL FOR ISSUE OF DOCUMENTS File No: G07/2393 Document Status: Draft V5 Program No: 2601376 Date of Issue: 12 February 2009 Document No: 351347 Client: ACTEW Corporation Project Title: ENLARGED COTTER DAM FISH MANAGEMENT PLAN (VERSION 1) Description: Fish Management Plans for the planning, design, construction and operational phases of the Enlarged Cotter Dam Position Name Laslo Nagy, Lara Brunner, Kate Elliott and Prepared by: Mark Lintermans ACTEW Review by: Chris Webb Signature: Date: For further information on this document, contact: Chris Webb Program Manager Approvals Water Security – Major Projects ACTEW Corporation Phone: 02 6175 2443 Mobile: 0414 516 563 E-mail: [email protected] Document Revision Control Version Description of Revision Person Making Issue Date V1 Draft for stakeholder review Kate Elliott 04.04.2008 V2 Draft for peer review Laslo Nagy 30.05.2008 V2A Draft with (some) peer review comments Laslo Nagy 14.07.2008 V3 Draft with peer review comments Laslo Nagy 02.09.2008 V4 Final Draft 2008 Laslo Nagy 10.09.2008 V5 Final Draft 2009 Laslo Nagy 12.02.2009 © ActewAGL Distribution This publication is copyright and contains information that is the property of ActewAGL Distribution. It may be reproduced for the purposes of use while engaged on ActewAGL Distribution commissioned projects, but is not to be communicated in whole or in part to any third party without prior written consent. ENLARGED COTTER DAM FISH MANAGEMENT PLAN (VERSION 1) ii TABLE OF CONTENTS Abbreviations ................................................................................................................. v Executive Summary ....................................................................................................... vi 1. Introduction ............................................................................................................ 1 1.1. Background .................................................................................................... 1 1.2. Objective of report ......................................................................................... 2 1.3. Process for updating ECD Fish Management Plan ...................................... 3 2. Summary of Current Monitoring in the Cotter Catchment .................................... 5 2.1. Rainfall and river flow ................................................................................... 5 2.2. Water quality monitoring ............................................................................... 6 2.3. Fish population surveys and monitoring ....................................................... 7 2.4. River Health ................................................................................................... 7 2.5. Climate change observation and projections ................................................ 7 3. Summary of Current Knowledge and Projects to Address Knowledge Gaps ........ 9 3.1. Background .................................................................................................... 9 3.2. Location specific ecological impacts ........................................................... 17 3.3. Knowledge gaps ........................................................................................... 19 3.4. Associated Projects ...................................................................................... 39 3.5. Summary Risks ............................................................................................. 40 4. Legislative requirements ...................................................................................... 42 4.1. Commonwealth legislation ........................................................................... 42 4.2. Territory legislation ..................................................................................... 46 5. ECD and Intended Operational Regime .............................................................. 49 5.1. Introduction .................................................................................................. 49 5.2. Modelling and anticipated operational regime ........................................... 50 5.3. Implications for aquatic habitat and habitat mitigation measures .............. 51 6. Fish Management Plans ...................................................................................... 53 ENLARGED COTTER DAM FISH MANAGEMENT PLAN (VERSION 1) iii 6.1. Current System ............................................................................................. 53 6.2. Design Phase ............................................................................................... 56 6.3. Construction Phase ...................................................................................... 59 6.4. Filling and Operational Phases ................................................................... 63 6.5. Risk assessment process ............................................................................... 67 6.6. Risks and mitigation measures ..................................................................... 68 7. Process for Updating ECD Fish Management Plans .......................................... 81 8. Bibliography ........................................................................................................ 82 ENLARGED COTTER DAM FISH MANAGEMENT PLAN (VERSION 1) iv ABBREVIATIONS ACT Australian Capital Territory ACTEW ACTEW Corporation Ltd ActewAGL Public/private company operating ACT water supply under contract DO Dissolved Oxygen ECD Enlarged Cotter Dam EHN Epizootic Haematopoietic Necrosis EIS Environmental Impact Statement EMP Environmental Management Plans EPBC Act Environment Protection and Biodiversity Conservation Act 1999 (Commonwealth of Australia) FSL Full supply level FWO Future Water Options GL Gigalitre (1,000,000,000 litres) Kg Kilogram km Kilometre MDBC Murray-Darling Basin Commission ML Megalitre (1,000,000 litres) m metre mm millimetre MNES Matter of national environmental significance NC Act Nature Conservation Act 1980 (ACT) TAMS Territory and Municipal Services ºC degrees Celsius ENLARGED COTTER DAM FISH MANAGEMENT PLAN (VERSION 1) v EXECUTIVE SUMMARY Background In October 2007, ACTEW and the ACT Government announced the commencement of detailed planning and construction of the Enlarged Cotter Dam (ECD), thereby increasing its current capacity from 3.8 gigalitres (GL) to 78 GL. The ECD raises environmental issues regarding the management of the following four threatened fish or crayfish species: • Macquarie Perch (Macquaria australasica). • Trout Cod (Maccullochella macquariensis). • Two-spined Blackfish (Gadopsis bispinosus). • Murray River Crayfish (Euastacus armatus). The ECD triggers the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), due to the presence of Macquarie Perch and Trout Cod. Both these species are listed under the EPBC Act as “endangered” and thus enlargement requires the approval of the Commonwealth Minister for the Environment. The ECD also triggers the ACT Nature Conservation Act 1980 (NC Act), due to the presence of Macquarie Perch (endangered status), Trout Cod (endangered status), Two- spined Blackfish (vulnerable status) and Murray River Crayfish (vulnerable status). Under this Act, ACTEW will need to obtain a licence from the ACT Conservator of Flora and Fauna before proceeding with enlargement. The ECD poses a number of problems as well as opportunities for fish management in the Cotter River catchment (ACT Government, 2007a; Lintermans, 2005). To obtain the relevant licences and approvals in accordance with Commonwealth and ACT legislation, ACTEW will need to provide sufficient information on how it proposes to protect the threatened fish species during the construction, filling and operational phases of the ECD. Objective of this document The overarching objective of the ECD Fish Management Plan is to: • Ensure that the aquatic communities and habitats of the lower Cotter River are maintained or rehabilitated to support native fish and crayfish species. ENLARGED COTTER DAM FISH MANAGEMENT PLAN (VERSION 1) vi This overarching objective is based on the visions, goals, objectives, and actions developed by the ACT Aquatic Species and Riparian Zone Conservation Strategy (ACT Government, 2007a). The ECD Fish Management Plan needs to be: • Designed to prevent or mitigate risks to threatened aquatic fauna and their habitats. • Scientifically based, using adaptive management. • Robust in terms of stakeholder involvement, peer review and public transparency. • Timely, and developed as part of the overall requirements of the ECD. • Effective in terms of resources and personnel whilst at the same time protecting threatened species. Consequently, the ECD Fish Management Plan needs to make full use of existing relevant environmental information, but at the same time identify and address knowledge gaps. Knowledge gaps A number of projects have been identified to fill specific knowledge gaps. Some of these are completed or currently under investigation, whereas a number will still need