Rich-Avon Weir Connection Feasibility Study NORTH CENTRAL CMA
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Rich-Avon Weir Connection Feasibility Study NORTH CENTRAL CMA Final IS064500 23 December 2015 Rich-Avon Weir Connection Feasibility Study Rich-Avon Weir Connection Feasibility Study Project no: IS064500 Document title: Rich-Avon Weir Connection Feasibility Study Document no: IS064500 Revision: Final Date: 23 December 2015 Client name: North Central CMA Project manager: Dr Josh Hale Author: Dr Josh Hale, Dr Andrew Sharpe, Sarah Heard, Dr Drew King, Amanda Woodman, Steve Parsons Jacobs Group (Australia) Pty Limited ABN 37 001 024 095 Floor 11, 452 Flinders Street Melbourne VIC 3000 PO Box 312, Flinders Lane T +61 3 8668 3000 F +61 3 8668 3001 www.jacobs.com COPYRIGHT: The concepts and information contained in this document are the property of Jacobs Group (Australia) Pty Limited. Use or copying of this document in whole or in part without the written permission of Jacobs constitutes an infringement of copyright. IS064500 i Rich-Avon Weir Connection Feasibility Study Contents Executive Summary .............................................................................................................................................. iv 1. Introduction ................................................................................................................................................ 1 1.1 Purpose and scope of the Rich-Avon Weir Pool Connection Feasibility Study .............................................................................. 1 1.2 Structure of this plan ....................................................................................................................................................................... 2 2. Site overview .............................................................................................................................................. 3 2.1 Catchment setting ........................................................................................................................................................................... 3 2.1.1 Climate ............................................................................................................................................................................................ 3 2.1.2 Hydrophysical characteristics ......................................................................................................................................................... 3 2.1.3 Natural morphology of the river in the area near the weir pool ....................................................................................................... 3 2.2 Physical characteristics of the weir pool ......................................................................................................................................... 5 2.2.1 Weir construction ............................................................................................................................................................................ 5 2.2.2 Physical surveys carried out as part of previous studies ................................................................................................................ 5 2.2.3 Physical surveys carried out as part of the current study ............................................................................................................... 6 2.3 Land status and management ........................................................................................................................................................ 9 3. Hydrology and hydrogeology of the Rich-Avon Weir Pool ................................................................. 10 3.1 Operational history ........................................................................................................................................................................ 10 3.2 The natural flow regime ................................................................................................................................................................ 11 3.3 Diversions from the system........................................................................................................................................................... 12 3.4 Climate change ............................................................................................................................................................................. 13 3.5 Groundwater surface water interactions ....................................................................................................................................... 13 3.5.1.1 Hydrogeological Setting ................................................................................................................................................................ 13 3.5.1.2 Potential impacts of groundwater on surface water ...................................................................................................................... 16 4. Management of environmental water .................................................................................................... 17 4.1 Management of environmental water ........................................................................................................................................... 17 4.2 Related agreements, policy, plans and activities .......................................................................................................................... 18 4.3 Environmental watering delivery ................................................................................................................................................... 18 5. Social values ............................................................................................................................................ 20 5.1 Cultural heritage............................................................................................................................................................................ 20 5.2 Recreation..................................................................................................................................................................................... 21 5.3 Economic assessment .................................................................................................................................................................. 21 5.3.1 Value ............................................................................................................................................................................................. 21 5.3.2 Asset management ....................................................................................................................................................................... 22 6. Review of historic water quality in the weir pool ................................................................................. 23 6.1.1 pH ................................................................................................................................................................................................. 23 6.1.2 Salinity .......................................................................................................................................................................................... 23 6.1.3 Nutrients........................................................................................................................................................................................ 24 6.1.4 Turbidity ........................................................................................................................................................................................ 24 6.1.5 Potential Acid Sulfate Soils ........................................................................................................................................................... 25 7. Review of ecological values ................................................................................................................... 26 7.1 Water dependent fauna and flora values ...................................................................................................................................... 26 IS064500 ii Rich-Avon Weir Connection Feasibility Study 7.1.1 Values expected prior to the installation of the Rich-Avon Weir ................................................................................................... 26 7.1.2 Values expected to be supported after the Rich-Avon Weir was constructed and during its operation as a permanent weir pool. .............................................................................................................................................................................................. 28 7.1.3 Current environmental values (determined from site assessments in November 2014 and September 2015) ............................ 30 7.1.4 Summary (including listings) ......................................................................................................................................................... 40 7.2 Terrestrial flora and fauna that depend on the riparian woodland habitat .................................................................................... 42 7.2.1 Values expected prior to the installation of the Rich-Avon Weir ................................................................................................... 42 7.2.2 Values expected to be supported after the Rich-Avon Weir was constructed