REVIEW OF THE ACT WATER RESOURCES ENVIRONMENTAL FLOW GUIDELINES 2013 November 2017 Final Report to Environment, Planning and Sustainable Development Directorate. APPLIEDECOLOGY.EDU.AU ACT ENVIRONMENTAL FLOW GUIDELINES: REVIEW Prepared for: Environment, Planning and Sustainable Development Directorate, ACT Government Produced by: Institute for Applied Ecology appliedecology.edu.au University of Canberra, ACT 2601 Telephone: (02) 6201 2795 Facsimile: (02) 6201 5651 Authors: Dr. Adrian Dusting, Mr. Ben Broadhurst, Dr. Sue Nichols, Dr. Fiona Dyer This report should be cited as: Dusting,A., Broadhurst, B., Nichols, S. and Dyer, F. (2017) Review of the ACT Water Resources Environmental Flow Guidelines 2013. Final report to EPSDD, ACT Government. Institute for Applied Ecology, University of Canberra, Canberra. Inquiries regarding this document should be addressed to: Dr. Fiona Dyer Institute for Applied Ecology University of Canberra Canberra 2601 Telephone: (02) 6201 2452 Facsimile: (02) 6201 5651 Email: [email protected] Document history and status Version Date Issued Reviewed by Approved by Revision Type Draft 07/08/2017 IAE EFG review Adrian Dusting Internal team Final 11/08/2017 Adrian Dusting Fiona Dyer Internal Final - revised 15/11/2017 ACT Gov. steering Adrian Dusting External committee, EFTAG, MDBA Front cover photo: Cotter River at Top Flats. Photo by Fiona Dyer APPLIEDECOLOGY.EDU.AU ii ACT ENVIRONMENTAL FLOW GUIDELINES: REVIEW TABLE OF CONTENTS Executive Summary ......................................... vii Background and Objective .......................................................................................................................................... vii Results and Conclusions ............................................................................................................................................. vii Introduction ...................................................... 1 History of ACT environmental flow guidelines .............................................................................................................1 Scope and approach of review .....................................................................................................................................1 Timing and context ...................................................................................................................................................1 Review scope ............................................................................................................................................................1 Review approach ......................................................................................................................................................2 Report structure ...........................................................................................................................................................2 Current Environmental Flow Guidelines ............. 3 Purpose and framework of current guidelines .............................................................................................................3 Framing Environmental flows .......................................................................................................................................3 Environmental flow provision in the ACT .....................................................................................................................4 Objectives of environmental flows in the ACT .............................................................................................................5 Adaptive management .................................................................................................................................................6 Policy and strategy context ..........................................................................................................................................6 Evaluation of Current EFG .................................. 7 Hydrological conditions ................................................................................................................................................7 Compliance with environmental flows .........................................................................................................................9 Water Supply Ecosystems .........................................................................................................................................9 Natural Ecosystems ............................................................................................................................................... 13 Modified Ecosystems ............................................................................................................................................. 13 Created Ecosystems ............................................................................................................................................... 14 Monitoring and evaluating ecological objectives of EFG .......................................................................................... 16 Assessment summary – Water Supply Ecosystems ............................................................................................... 16 Natural Ecosystems ............................................................................................................................................... 16 Modified Ecosystems ............................................................................................................................................. 17 Created Ecosystems ............................................................................................................................................... 17 Evaluation conclusions .............................................................................................................................................. 22 Future of environmental flow guidelines .......... 23 Alignment with the Murray-Darling Basin PLan ........................................................................................................ 23 The Basin Plan ....................................................................................................................................................... 24 Priority Environmental Assets and Priority Ecosystem Functions ......................................................................... 24 Basin-wide environmental watering strategy (BWS) ............................................................................................ 25 Climate change .......................................................................................................................................................... 28 Recommendations from previous EFG reviews ........................................................................................................ 28 Recommendations and considerations for revised EFG 30 Approach ................................................................................................................................................................... 30 Knowledge gaps ......................................................................................................................................................... 30 Relationship of review report to EFG ........................................................................................................................ 31 Recommendations for EFG framework and Implementation 31 Adaptive management .......................................................................................................................................... 35 Operational flexibility ............................................................................................................................................ 35 Other constraints on e-flow provision ................................................................................................................... 36 APPLIEDECOLOGY.EDU.AU iii ACT ENVIRONMENTAL FLOW GUIDELINES: REVIEW Recommendations for objectives, flows and indicators 37 Water Supply Ecosystems .......................................................................................................................................... 37 Reaches upstream of impoundments ....................................................................................................................... 38 Upstream of Corin, including unregulated tributaries .......................................................................................... 38 Reaches upstream of Googong Reservoir ............................................................................................................. 39 Corin Reservoir ...................................................................................................................................................... 40 Googong Reservoir ................................................................................................................................................ 41 Reaches between impoundments ............................................................................................................................. 42 Corin Dam to Bendora Reservoir, Bendora Dam to Cotter Reservoir .................................................................... 42 Bendora and Cotter reservoirs .............................................................................................................................