Kerang Lakes Bypass
Investigation Project Technical Report
MIDDLE REEDY LAKE
PREPARED FOR THE GOULBURN-MURRAY WATER CONNECTIONS PROJECT
FEBRUARY 2014 Kerang Lakes Bypass Investigation Project Technical Report – Reedy Lake
DOCUMENT HISTORY AND STATUS Version Date Issued Prepared By Reviewed By Date Approved Version 1 8 July 2013 Bree Bisset Michelle Maher and N/A Rohan Hogan Version 2 4 September 2013 Bree Bisset and Michelle Maher G-MW CP SRP 25 September 2013 Version 3 4 October 2013 Bree Bisset and Michelle Maher G-MW CP ERP TBC Version 4 5 November 2013 Bree Bisset and Michelle Maher Final draft TBC Version 5 12 December 2013 Bree Bisset Rohan Hogan 14 January 2014 Version 6 14 January 2014 Bree Bisset G-MW CP – Pat Feehan DISTRIBUTION Version Date Quantity Issued To Version 1 8 July 2013 Internal Michelle Maher Version 2 4 September 2013 Email / Hard copy G-MW CP SRP Version 3 4 October 2013 Email / Hard copy G-MW CP ERP Version 4 5 November 2013 Email G-MW CP – Pat Feehan Version 5 12 December 2013 Email Rohan Hogan Version 6 14 January 2014 Email G-MW CP – Pat Feehan DOCUMENT MANAGEMENT Printed: 28 March 2014 Last saved: 28 March 2014 12:18 PM File name: NCCMA-85098 – KLBIP Middle Reedy Lake Technical Report Authors: Bree Bisset and Michelle Maher Name of organisation: North Central CMA Name of document: KLBIP Technical Report Middle Reedy Lake Document version: Version 6 Document manager: 85098
For further information on any of the information contained within this document contact: North Central Catchment Management Authority PO Box 18 Huntly Vic 3551 T: 03 5440 1800 F: 03 5448 7148 E: [email protected] www.nccma.vic.gov.au © North Central Catchment Management Authority, 2014 Front cover photo: Ibis breeding event in December 2010, Heath Dunstan (DEPI)
The Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake is a working document, compiled from the best available information. It will be subject to revision in the future as new information becomes available. This publication may be of assistance to you, but the North Central Catchment Management Authority and its employees do not guarantee that the publication is without flaw of any kind, or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on information in this publication. Please cite this document as: North Central CMA (2014). Kerang Lakes Bypass Investigation Project Technical Report –Middle Reedy Lake, North Central Catchment Management Authority, Huntly. Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
EXECUTIVE SUMMARY
The Kerang Lakes Bypass Investigation Project (KLBIP) investigates the feasibility of constructing bypass channels around the Reedy Lakes Complex (comprising First, Middle and Third Reedy Lakes), Little Lake Charm and Racecourse Lake. The project, which is part of Goulburn-Murray Water’s (G-MW) Business Case to support Stage 2 of the G-MW Connections Project, aims to remove irrigation demand and develop a variable water regime that will enhance wetland environmental values. Middle Reedy Lake is a 179 ha permanent open freshwater lake located approximately ten kilometres north-west of Kerang. The wetland is part of the Kerang Lakes Ramsar Site and lies between First Reedy Lake at its south and Third Reedy Lake at its north. The permanent operation of Middle Reedy Lake since the 1920s has altered the values of the wetland significantly. The small band of littoral vegetation, low species diversity and high weediness is a result of the prolonged stable water levels. However the wetland still provides habitat for a range of flora and fauna species listed under various international, national and Victorian state legislations including species listed under the Environment Protection and Biodiversity Conservation Act 1999. First Reedy Lake also supports an extensive community of aquatic Tangled Lignum which makes the wetland important for colonial waterbird breeding particularly Australian White Ibis, Straw-necked Ibis and Royal Spoonbill. Background information, hydrogeological assessments, flora and fauna surveys as well as technical input was used to determine the preferred environmental water management goal and appropriate water regime for Middle Reedy Lake as summarised below:
Management goal To provide a permanent regime that introduces seasonal variability to the water level at the littoral zone, creating drawdown zones, promoting growth and increased health of Tangled Lignum as well as the re- establishment of submerged and floating macrophytes throughout the wetland. This will promote improved conditions for colonial nesting waterbirds and increased opportunities for turtles, frogs and fish.
Preferred regime To provide a watering regime that reintroduces variability in the water level at the littoral zone of Middle Reedy Lake, promoting an increase in the extent and health of Tangled Lignum as well as re- establishment of submerged and floating macrophytes. Provide fresh inflows annually to maintain a variable depth of between 74.88m AHD (FSL) and 74.57m AHD (1.7m depth).
This Technical Report also assesses the associated benefits and risks and proposes mitigation strategies required to manage the wetland under the preferred regime. This report also provides a number of recommendations to address key knowledge gaps associated with the project.
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CONTENTS PAGE
EXECUTIVE SUMMARY ...... 2 CONTENTS PAGE ...... 3 LIST OF FIGURES ...... 4 LIST OF TABLES ...... 4 ACKNOWLEDGEMENTS ...... 5 ABBREVIATIONS ...... 6 1. GOULBURN-MURRAY WATER CONNECTIONS PROJECT ...... 8 2. PURPOSE AND SCOPE OF DOCUMENT ...... 8 3. BACKGROUND ...... 9 3.1. RAMSAR CONVENTION ...... 11 4. MIDDLE REEDY LAKE ...... 14 4.1. BACKGROUND ...... 14 5. WATER DEPENDENT VALUES ...... 15 5.1. LISTING AND SIGNIFICANCE ...... 15 5.2. FLORA ...... 15 5.3. FAUNA ...... 20 5.4. REPRESENTATIVENESS AND DISTINCTIVENESS ...... 23 5.5. MIDDLE REEDY LAKE IN THE RAMSAR CONTEXT ...... 24 6. HYDROLOGY ...... 25 6.1. NATURAL REGIME ...... 25 6.2. HISTORIC /CURRENT WATER MANAGEMENT ...... 25 6.3. TRAJECTORY FOR THE ENVIRONMENTAL VALUES OF MIDDLE REEDY LAKE UNDER CURRENT WATER REGIME ...... 26 6.4. ALTERNATIVE WATER REGIME SCENARIOS FOR MIDDLE REEDY LAKE ...... 27 6.5. GROUNDWATER ...... 29 7. RATIONALE FOR RECOMMEND WATER REGIME ...... 29 8. MANAGEMENT OBJECTIVES...... 32 8.1. MANAGEMENT GOAL ...... 33 8.2. ECOLOGICAL AND HYDROLOGICAL OBJECTIVES ...... 33 8.3. PROPOSED WATER REGIME ...... 34 9. POTENTIAL RISK, ADVERSE IMPACTS AND BENEFITS ...... 38 9.1. IMPACT TO CURRENT RAMSAR CRITERIA ...... 38 9.2. RISK AND BENEFIT ASSESSMENT ...... 38 9.3. MITIGATION ASSESSMENT ...... 52 9.4. RISK AND MITIGATION SUMMARY ...... 56 10. KNOWLEDGE GAPS ...... 56 11. REFERENCES ...... 57 APPENDIX A: BATHYMETRY ...... 60 APPENDIX B: 2013 EVC MAPPING ...... 62 APPENDIX C: FLORA AND FAUNA SPECIES LIST ...... 63 APPENDIX D: WATER REQUIREMENTS OF ECOLOGICAL VALUES ...... 69 APPENDIX D: WATER REQUIREMENTS OF ECOLOGICAL VALUES ...... 69 Commercial-in-Confidence Page 3 of 74
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APPENDIX E: WATER REGIME SUMMARIES ...... 73 LIST OF FIGURES Figure 1: KLBIP development process ...... 9 Figure 2: KLBIP Location Map ...... 10 Figure 3: Map of the Kerang Wetland Ramsar Site ...... 12 Figure 4: Map of Middle Reedy Lake including key features ...... 14 Figure 5: A conceptual cross section of Middle Reedy Lake showing current conditions. Insert map shows cross section position (image not to scale)...... 17 Figure 6: A conceptual model of the littoral zone of Middle Reedy Lake as marked in Figure 5 (red) under the current regime...... 18 Figure 7: Predicted water levels under each proposed regime (Gippel, 2013) ...... 28 Figure 8: A conceptual cross section of Middle Reedy Lake under proposed regime. Insert map shows cross section position (image not to scale)...... 36 Figure 9: A conceptual model of the littoral zone of Middle Reedy Lake as marked in Figure 8 (red) under the proposed regime...... 37
LIST OF TABLES
Table 1: Kerang Wetlands Ramsar site satisfied criteria (KBR, 2011) ...... 13 Table 2: Relevant legislation, agreements, convention and listings recorded in Middle Reedy Lake ...... 15 Table 3: Current EVCs within Middle Reedy Lake and their bioregional conservation status (Rakali 2013) ...... 16 Table 4: Significant flora species recorded at Middle Reedy Lake ...... 19 Table 5: Bird breeding events at Middle Reedy Lake since 1985 ...... 21 Table 6: Significant fauna species recorded at Middle Reedy Lake ...... 22 Table 7: Current area of Permanent Open water across the landscape ...... 24 Table 8: Middle Reedy Lake against Ramsar Criteria ...... 24 Table 9: Middle Reedy Lake water level percentiles (June 1986 to May 2013) ...... 26 Table 10: Middle Reedy Lake wetting/drying calendar ...... 26 Table 11: Middle Reedy Lake proposed watering regime scenarios (North Central CMA, 2012) ...... 27 Table 12: Middle Reedy Lake modelling results (Fluvial Systems, 2012) ...... 27 Table 13: Middle Reedy Lake Groundwater Risk Assessment (URS, 2013) ...... 29 Table 14: Risk assessment associated with each watering regime scenario at Middle Reedy Lake ...... 32 Table 15: Previous management considerations ...... 32 Table 16: Proposed ecological objectives for Middle Reedy Lake ...... 33 Table 17: Current vs. proposed water regime Ramsar criteria compliance for Middle Reedy Lake ...... 38 Table 18: Benefit matrix ...... 39 Table 19: Risk matrix ...... 39 Table 20: Benefit assessment for the objective of restoring seasonal variability at the littoral zone to promote Tangled Lignum and re-establishment of submerged and floating macrophytes at Middle Reedy Lake...... 40 Table 21: Risk assessment for the objective of restoring variability at the littoral zone to promote Tangled Lignum and re-establishment of submerged and floating macrophytes at Middle Reedy Lake ...... 43 Table 22: Modified risk assessment ...... 53
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ACKNOWLEDGEMENTS Acknowledgement of Country The North Central Catchment Management Authority (North Central CMA) acknowledges Aboriginal Traditional Owners within the region, their rich culture and spiritual connection to Country. The North Central CMA also recognises and acknowledges the contribution and interest of Aboriginal people and organisations in land and natural resource management.
Contributions to the Middle Reedy Lake Technical Report The information contained in the Middle Reedy Lake Technical Report has been sourced from a variety of reports and field inspections and from individual knowledge and expertise. The North Central CMA acknowledges the assistance of the following people in preparing this document: • Pat Feehan, Ross Plunkett and Anne Graesser, Goulburn-Murray Water (G-MW) • Andrea Keleher and Janet Holmes, Department of Environment and Primary Industries (DEPI) • Scientific Panel Members: o Rhonda Butcher, Water's Edge Consulting o Daniel Stoessel, Arthur Rylah Institute (ARI) o Brett Lane, Brett Lane and Associates o Doug Frood, Pathways Bushland and Environment o Damien Finlayson, URS • Damien Cook, Rakali Ecological Consulting • Anthony Byrne and Gavin Thomas, Biosis • Kerang Lakes Bypass Investigation Project Reference Group • Kerang Lakes Bypass Investigation Community Advisory Group • Expert Review Panel: Terry Hillman and Jane Roberts • Louissa Rogers, Emer Campbell, Tim Shanahan and Peter McRostie, North Central CMA.
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ABBREVIATIONS AAV Aboriginal Affairs Victoria BE Bulk Entitlement Bonn Convention on the Conservation of Migratory Species of Wild Animals CAMBA China–Australia Migratory Bird Agreement CMA Catchment Management Authority DEPI Department of Environment and Primary Industries EES Environment Effects Statement EPBC Environment Protection and Biodiversity Conservation Act 1999 EVC Ecological Vegetation Class EWP Environmental Watering Plan FFG Flora and Fauna Guarantee Act 1988 FSL Full Supply Level GIS Geographic Information Systems GL Gigalitre (one billion litres) GMID Goulburn Murray Irrigation District G-MW Goulburn–Murray Water JAMBA Japan–Australia Migratory Bird Agreement MNES Matters of National Environmental Significance North Central CMA North Central Catchment Management Authority NVIRP Northern Victoria Irrigation Renewal Project ROKAMBA Republic of Korea–Australia Migratory Bird Agreement TIS Torrumbarry Irrigation System VEAC Victorian Environmental Assessment Council
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GLOSSARY OF TERMS
Adaptive A systematic process for continually improving management policies and practices by management learning from the outcomes of previously employed policies and practices Episodic Wetland alternates between holding water and being completely dry, with the dry phase being the usual state; flooding occurs rarely and irregularly; surface water
persists for months EVC Ecological Vegetation Class is a vegetation classification system that groups vegetation communities based on floristic, structural and ecological features Full supply The normal maximum operating water level in water storage when not affected by level floods Intermittent Wetland alternates between holding water and being completely dry, but not a nnually as in seasonal wetlands; surface water persists for months to years Littoral zone Also known as edge zone is characterised by coarser sediments, more habitat structure, and is usually regarded to extend from the surface to the end of the euphotic zone. The euphotic zone is the depth to which light penetrates through the water column and enables photosynthesis – in lakes and deep wetlands this is often restricted to the margins of the wetland. In shallow wetlands it can expand across the whole wetland Semi - Wetland usually holds some water, with annual inflows being equal to or exceeding permanent minimum losses in 90 per cent of years; surface water persists for decades, only drying out in extreme droughts Vegetative A form of asexual reproduction in plants, in which multicellular structures become reproduction detached from the parent plant and develop into new individuals that are genetically identical to the parent plant. In Lignum this usually occurs through broken off branches (Price Merrett, 2008).
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1. Goulburn-Murray Water Connections Project The Goulburn-Murray Water (G-MW) Connections Project is a $2 billion works program to upgrade ageing irrigation infrastructure across the Goulburn Murray Irrigation District (GMID) and to save water lost through leakage, seepage, evaporation and system inefficiencies. Works will include lining and automating channels, building pipelines and installing new, modern metering technology. The GMID uses a number of natural carriers, rivers, lakes and wetlands for both storage and conveyance of water. While the water savings generated are from ‘losses’ within the irrigation system, in some cases the losses from the operating regime provides incidental benefits to environmental assets (SKM, 2008). Stage 1 of the G-MW Connections Project will implement water distribution and delivery efficiency improvements to deliver an estimated 225 GL/ year (Long Term Cap Equivalent-LTCE) water savings. This recovered water is returned as additional bulk water entitlement for use by irrigators, the environment and other funders. Stage 2 of the project is intended to recover an additional estimated 204 GL/ yr (LTCE) of water by 2017/18. The water recovered from this project is funded by the Commonwealth Government and retained for environmental use (G-MW, 2013a). The Business Case to support Stage 2 provided for a number of ‘Special Projects’ to achieve benefits such as water savings, environmental enhancement and/or improved customer level of service. The Kerang Lakes Bypass investigation Project (KLBIP) has been identified as a ‘Special Project’ under the NVIRP Stage 2 Business Case (now known as G-MW Connections Project). This project proposes to remove irrigation demand and develop a variable water regime that will enhance the environmental values of the lakes. 2. Purpose and scope of document The purpose of this Technical Report (Middle Reedy Lake) is to document the environmental values, hydrology, modelled wetland watering regimes, potential impact pathways for the alternative water regimes, refinement of the environmental objectives and water regimes and completion of a risk assessment for discussion by the Kerang Lakes Bypass Investigation Project Reference Group (PRG). The recommended environmental water regime documented in this report will be used to assess potential water savings and is an important input to the development of a business case for the Kerang Lakes Bypass. It is intended that this Technical Report is a working document and information presented should be considered in this context. The tasks undertaken to develop the technical report are illustrated in Figure 1. This report has been reviewed by the Project Reference Group, a scientific review panel and the Connections Project Expert Review Panel. The information in this report may be used at a later date to develop an environmental water plan for the wetland.
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Figure 1: KLBIP development process 3. Background The Kerang Lakes Bypass Investigation Project (KLBIP) will investigate the feasibility of the concept to construct bypass channels around the Reedy Lakes Complex (comprising First, Middle and Third Reedy Lakes), Little Lake Charm and Racecourse Lake (Figure 2). These systems will be referred to as wetlands in this report when not referred to by name. The wetlands are operated as part of the irrigation conveyance system in the Torrumbarry Irrigation Area (TIA). The bypass project has been funded as part of Stage 2 of the Goulburn-Murray Water (G-MW) Connections Project. If the investigation deems that the bypass is feasible, G-MW Connections will prepare a Business Case for the Australian Government to secure implementation funding.
The five wetlands are of international and national significance being part of the Kerang Wetlands Ramsar site and are listed in the Directory of Important Wetlands in Australia.
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Figure 2: KLBIP Location Map
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3.1. Ramsar Convention The Convention on Wetlands of International Importance, otherwise known as the Ramsar Convention, provides the framework for actions on a local, regional and national scale as well as international cooperation, for conservation and wise use of wetlands. Currently there are 168 contracting parties managing over 2,000 Ramsar wetland sites worldwide.
In 1982 the Kerang Wetlands Ramsar site was designated under the Convention of Wetlands of International Importance (Ramsar Convention) as a Wetland of International Importance (Ramsar wetland) (DEWHA, 2008). The site occupies 9,419 ha and is made up of 23 named permanent and temporary wetlands, including permanent freshwater lakes, permanent saline/ brackish/ alkaline lakes, permanent freshwater marshes and seasonal/ intermittent freshwater marshes (Clunie, 2010). Figure 3 illustrates the wetlands that are part of the Kerang Wetlands Ramsar Site.
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Figure 3: Map of the Kerang Wetland Ramsar Site
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To be listed under the Ramsar Convention, wetlands must meet one or more of the internationally accepted criteria. When the Kerang Wetlands Ramsar site was originally designated as Ramsar listed, it satisfied three of the criteria. In 2005 the Ramsar Criteria was updated and the Kerang Wetlands Ramsar site was recognised as satisfying criteria 1, 2, 3, 4, 5 and 6 (Table 1) (Hale, 2009; KBR, 2011). The collective ecological components and processes of the site provide the foundation to its recognised ecosystem values and importance. As well as ecological value, the site is also of significant economic, cultural, spiritual and recreational value. Refer to Landscape Scale Consideration Report (North Central CMA, 2014) for Ramsar listing justification.
Table 1: Kerang Wetlands Ramsar site satisfied criteria (KBR, 2011) Group A: Sites containing representative, rare or unique wetland types
A wetland should be considered internationally important if it contains a representative, rare, or Criterion 1 unique example of a natural or near-natural wetland type found within the appropriate biogeographic region.
Group B: Sites of international importance for conserving biological diversity
Criteria specific to species and ecological communities:
A wetland should be considered internationally important if it supports vulnerable, endangered, or Criterion 2 critically endangered species or threatened ecological communities.
A wetland should be considered internationally important if it supports populations of plant and/or Criterion 3 animal species important for maintaining the biological diversity of a particular biogeographic region.
A wetland should be considered internationally important if it supports plants and/or animal species Criterion 4 at a critical stage in their life cycles, or provides refuge during adverse conditions.
Criteria specific to waterbirds:
A wetland should be considered internationally important if it regularly supports 20,000 or more Criterion 5 waterbirds.
A wetland should be considered internationally important if it regularly supports 1% of the Criterion 6 individuals in a population of one species or subspecies of waterbird.
As a contracting Party to the Ramsar Convention, Australia has the responsibility of managing sites designated as Wetlands of International Importance. This responsibility includes maintaining the ecological character of the site and informing the Ramsar Secretariat of any changes (DEWHA, 2008).This concerns change to ecological character rather than the change to the criteria for which it was listed (DSE, 2006). The Ramsar Convention has defined “ecological character” and “change in ecological character” as (Ramsar, 2005):
• “Ecological character is the combination of the ecosystem components, processes and benefits/services that characterise the wetlands at a given point in time” and
• “…change in ecological character is the human induced adverse alteration of any ecosystem component, process and or ecosystem benefit/service.”
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4. Middle Reedy Lake 4.1. Background Middle Reedy Lake (also known as Middle Lake and Second Reedy Lake) is a 179 hectare wetland located approximately ten kilometres north-west of Kerang. The site lies between First Reedy Lake at its south and Third Reedy Lake at its north (Figure 2) and has been held artificially full (between 74.57m AHD and the full supply level 1 (FSL) of 74.88m AHD) since its inclusion into the Torrumbarry Irrigation System in the 1920s (SKM, 2010). The bathymetry of Middle Reedy Lake shows that the wetland has a maximum depth of 2.04 metres. The bed shows a gradient incline of about half a metre to an extensive lignum community (refer to Section 5.2) (73.2m AHD) that curves around the centre of the western and southern sides of the wetland. The lignum extends to about 1.28 metres (73.6m AHD) when the wetland is at maximum depth (74.88m AHD). The bed continues to incline gradually past the lignum community on the western and southern edges of the wetland, whereas the eastern and north-eastern edges sharply incline to the high water mark due to a levy bank (refer to Appendix A for the wetland bathymetry map and the rating table prepared by Northern Land Solutions, 2012). Water entering the wetland originates from the Murray River through the Torrumbarry Irrigation System. The water is diverted from the Loddon Weir pool and enters First Reedy Lake via the Washpen regulator before travelling northward to Middle Reedy Lake (SKM, 2010). Figure 4 presents an aerial map of Middle Reedy Lake, including key features.
Figure 4: Map of Middle Reedy Lake including key features
1 Full supply level- the normal maximum operating water level in a water storage when not affected by floods. Commercial-in-Confidence Page 14 of 74
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5. Water dependent values 5.1. Listing and significance Legislation relevant to the management of species of Middle Reed Lake falls within one international convention, three international agreements, a national legislation and Victorian legislation and advisory listings are shown in Table 2. A full flora and fauna species list recorded at Middle Reedy Lake is shown in Appendix C. Table 2: Relevant legislation, agreements, convention and listings recorded in Middle Reedy Lake Legislation, Agreement or Convention Jurisdiction Listed Ramsar Convention International Japan Australia Migratory Birds Agreement (JAMBA) International China Australia Migratory Birds Agreement (CAMBA) International Korea Australia Migratory Birds Agreement (ROKAMBA) International × Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention) International × Environmental Protection and Biodiversity Conservation Act (EPBC Act) National Flora and Fauna Guarantee Act 1988 (FFG Act) State DSE advisory lists State 5.2. Flora Middle Reedy Lake is characterised as a permanent open freshwater lake with its deepest sections consisting of open water, with little to no aquatic vegetation. The western portion of the wetland supports the highly valued Lignum Swamp (EVC 104) 2, which is dominated by Tangled Lignum (Duma flourenta ) growing to heights of up to 4 metres tall (Rakali, 2013). Usually this EVC consists of species tolerant to low rainfall and infrequent inundation, however in Middle Reedy Lake (and to a lesser extent First Reedy Lake) this EVC has adapted to withstand permanent inundation and is the only community of its kind in Australia (Roberts and Marston, 2011) 3. The EVC is associated with Aquatic Herbland (EVC 653) vegetation and extends northwards. This zone, as well as a thin band around the entire littoral zone of the wetland, supports Tall Marsh (EVC 821) (various combinations present i.e. Tall Marsh/ Common Reed, Tall Marsh/ Cumbungi, Tall Marsh/ Giant Rush etc) and also contains a high abundance and density of dead River Red Gums (Eucalyptus camaldulensis ). The distribution follows the historical shoreline of the wetland which, when overlayed on the wetland’s bathymetry, shows that this zone would have extended to a depth of approximately 73.6m AHD (Ho et al. 2006, Northern Land Solutions, 2012). Localised areas support small patches of Giant Rush ( Juncus ingens ) and occasionally Common Reed (Phragmites australis ). Associated aquatic herbs include Clove-strip ( Ludwigia peploides subsp. montevidensis), Robust Water-milfoil ( Myriophyllum papillosum ) and Slender Knotweed ( Persicaria decipiens ) (Rakali, 2013).
The low elevations areas of the wetland are dominated by flood-stimulated species part of the EVC Intermittent Swampy Woodland (EVC 813). The zone is made up of a River Red Gum overstorey, with Tangled Lignum, Rat-tail Couch (Sporobolus mitchellii ), Hedge Saltbush ( Rhagodia spinescens), Roinsweed ( Cressa australis ) and Spring Flat-sedge (Cyperus gymnocaulos ) understorey. Closer to the water’s edge is a zone that supports herbs species which are characteristic of seasonal inundation,
2 EVC- Ecological Vegetation Class is a vegetation classification system that groups vegetation communities based on floristic, structural and ecological features. 3 “The presence of healthy and vigorous Lignum at Middle Reedy Lake is anomalous and unexplained as it generally does not occur in permanently waterlogged soils. Overwatering and ponding can be detrimental to Lignum” (Roberts and Marston, 2011, p66). Commercial-in-Confidence Page 15 of 74
Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake suggesting that these areas still experience wetting and drying phases. The higher elevations support bands of Lignum Swampy Woodland (EVC 823), particularly the western boundary and at the connecting channel to Third Reedy Lake, and Riverine Chenopod Woodland (EVC 103), most notably at the eastern boundary and scattered through the southern edge between First and Middle Reedy Lakes. The connecting channels and associated areas between the wetlands also support Lignum Shrubland (EVC 808) and Saltmarsh-grass Swamp (EVC A113) at the south and Semi-arid Chenopod Wooldand (EVC 98) at the north. DSE pre-1750s mapping predicts that the original vegetation of Middle Reedy Lake was dominated by Lignum Swampy Woodland (EVC 823), fringed by Riverine Chenopod Woodland (EVC 103) on its western shore and Semi-arid Chenopod Woodland (EVC 98) on the lunette of the eastern shore. Due to the assumed natural hydrology and bathymetry of the wetland, Rakali (2013) suggested that this mapping is inaccurate, with the wetland flooding to frequently and for too long to support this vegetation assemblage. This vegetation assemblage would be supported by a higher abundance of dead tree snags and stumps, which are virtually absent past one metre depth in the wetland (i.e. central areas). Instead it is likely that the dominate EVC of the deeper sections would have been Aquatic Herbland (EVC 653) when inundated and Lake Bed Herbland (EVC 107) when dry. The fringing zone would have been made up of Intermittent Swampy Woodland (EVC 813) which is evidenced by remnant patches of this EVC around the margins as well as drowned River Red Gums around the shallow edges of the wetland (Rakali, 2013). Records also indicate that large and diverse mats of aquatic plants, characteristic of Submerged Aquatic Herbland (EVC 918), inhabited the open water areas in the past, however it is likely that the decline is a result of the increased turbidity due to the presence of Common Carp ( Cyprinus carpio ) in the system (O’Donnell, 1990; Rakali, 2013). Table 3 lists and Appendix B illustrates all the EVCs present at Middle Reedy Lake and their conservation status within the Victorian Riverina bioregion. Figure 4 and Figure 6 show conceptual cross sections of Middle Reedy Lake.
Table 3: Current EVCs within Middle Reedy Lake and their bioregional conservation status (Rakali 2013) Bioregion EVC No. EVC Bioregional Conservation Status in the Victorian Riverina 1 98 Semi-arid Chenopod Woodland Endangered 103 Riverine Chenopod Woodland Vulnerable 104 Lignum Swamp Vulnerable Not listed for Victorian Riverina (Vulnerable in Murray Fans 653 Aquatic Herbland bioregion) (provisional status Endangered) Victorian 808 Lignum Shrubland Endangered Riverina 813 Intermittent Swampy Woodland Depleted 821 Tall Marsh Depleted 918 2 Submerged Aquatic Herbland Endangered 823 Lignum Swampy Woodland Vulnerable A113 3 Saltmarsh-grass Swamp Endangered 1EVC Bioregional Conservation Status updated using revised wetland BCS spreadsheet supplied by DEPI (compiled by D. Frood) 2Not observed in recent survey undertaken by Rakali (2013) but likely to be present. 3Provisional wetland descriptions are subject to change and, to date, have not been adopted within DSE’s vegetation quality assessment framework.
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Figure 5: A conceptual cross section of Middle Reedy Lake showing current conditions. Insert map shows cross section position (image not to scale).
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Figure 6: A conceptual model of the littoral zone of Middle Reedy Lake as marked in Figure 5 (red) under the current regime .
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In the recent survey by Rakali (2013), a total of 106 vascular plants were recorded at Middle Reedy Lake, with 67 of these indigenous. Ten of the indigenous species recorded during the survey had a Victorian Conservation status, however only six of these- Branching Groundsel ( Senecio cunninghamii var. cunninghamii ), Spiny Lignum ( Duma horrida subsp. horrida ), Salt Paperbark ( Melaleuca halmaturorum subsp. Halmaturorum) Swamp Buttercup ( Ranunculus undosus), Short Water-starwort (Callitriche brachycarpa ) and Twin-leaf Bedstraw ( Asperula gemella ) are considered water dependent. Both Short Water-starwort and Salt Paperbark are Flora and Fauna Guarantee Act 1988 (FFG Act) listed, however Salt Paperbark was determined to be the result of active planting and is not considered naturally occurring at Middle Reedy Lake. All of the water dependent species were recorded in Intermittent Swampy Woodland EVC, with Spiny Lignum also present in Riverine Chenopod Woodland and Branching Groundsel in the northern sections of Tall Marsh.
One of the water dependent species, Swamp Buttercup, which was also recorded in neighbouring First Reedy Lake during the recent Rakali (2013) survey, has not been recorded at Middle Reedy Lake since 1977 (DEPI, 2013; Ho et al. 2006 ; SKM, 2010; Rakali, 2013). There are no listed Environmental Protection and Biodiversity Conservation Act 1999 (EPBC) listed species recorded at Middle Reedy Lake. Table 4 summarised the significant species, their water dependency and listings at Middle Reedy Lake.
Table 4: Significant flora species recorded at Middle Reedy Lake Common Name Scientific Name Water Last IUCN EPBC FFG Victorian dependency 1 record Red status status Conservation List status Branching Senecio cunninghamii var. W 2013 r Groundsel cunninghamii Brown Beetle- Leptochloa fusca subsp. fusca T 2009 r grass Flat-top Atriplex lindleyi subsp. lindleyi T 2013 k Saltbush
Native Couch Cynodon dactylon var. pulchellus T 2013 k Short Water- Callitriche brachycarpa A 2013 L v starwort
Spiny Lignum Duma horrida subsp. horrida W 2013 r Swamp Ranunculus undosus T / W 1977 v Buttercup Twin-leaf Asperula gemella T / W 2013 r Bedstraw Melaleuca halmaturorum subsp. Salt Paperbark 2 W 2013 L v halmaturorum Spreading Emu- Eremophila divaricata subsp. T 2013 r bush 2 divaricata Conservation Status: • Water dependency: T- River terrestrial, A- River aquatic, W- wetland dependent • IUCN: EX- Extinct, EW- extinct in the wild, CR- critically endangered, EN- endangered, VU- vulnerable, NT- near threatened, LC- least concern, DD- data deficient • EPBC: VU – Vulnerable, EN- Endangered • FFG status: L – Listed as threatened • DSE status: e- Endangered, v- Vulnerable, r- rare, n– Near Threatened, k- Poorly known, d- data deficient • 2Planted species 1Water Dependency advised by Significant wetland-dependent flora species spreadsheet supplied by DEPI (compiled by D. Frood) and VEAC, 2008.
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Although not considered a significant species, extensive stands of Tangled Lignum ( Duma florulenta) provide an extremely important habitat component at Middle Reedy Lake supporting high numbers of colonial nesting waterbirds (i.e. known as the Ibis Rookery), refer to Section 5.3. It is believed that the Tangled Lignum has only been able to vegetatively 4 reproduce since the wetland was included in the Torrumbarry Irrigation System, and as a result the health of the lignum is declining. Aerial photographs from 1944 and 2012 show a decrease in density (centre dying) and an outward shift in the extent of the lignum clumps (Plate 1 and Plate 2) (Rakali, 2013). There is a real concern that the spread of Tangled Lignum will or is reducing due to the high water depth surrounding the community.
Plate 1: Middle Reedy Lake in 1944 Plate 2: Middle Reedy Lake in 2012 5.3. Fauna In total 89 bird species, ten native fish, two turtle and four frog species have been recorded at Middle Reedy Lake (Ho et al. 2006; SKM, 2010; Rakali, 2013; Biosis, 2013, DEPI, 2013). Fifteen waterbird species are considered significant including three that are FFG listed, have a Victorian Conservation status and are listed under migratory agreements– Eastern Great Egret ( Ardea modesta ), White-bellied Sea-eagle (Haliaeetus leucogaster ) and Caspian Tern ( Hydroprogne caspia). Please also note that all species listed in Appendix C of the family Anatidae (ducks) are also considered migratory under the EPBC Act as per the Convention of International Trade in Endangered Species (CITES) of wild flora and fauna. A further four species – Blue-billed Duck ( Oxyura australis ), Freckled Duck ( Stictonetta naevosa ), Grey-crowned Babbler (Pomatostomus temporalis temporalis ) and Gull-billed Tern ( Sterna nilotica ) are also FFG listed and have an endangered Victorian Conservation status. In recent surveys by Biosis (2013) and Rakali (2013) only five of the fifteen significant waterbird species were recorded, including Caspian Tern, Grey-crowned Babbler, White-bellied Sea-Eagle, Pied Cormorant ( Phalacrocorax varius ) and Royal Spoonbill ( Platalea regia ). The most recent records for all the other significant species are from between 1988 and 2012 (DEPI, 2013, BirdLife Australia, 2013). Refer to Table 6.
4 A form of asexual reproduction in plants, in which multicellular structures become detached from the parent plant and develop into new individuals that are genetically identical to the parent plant. In Lignum this usually occurs through broken off branches (Price Merrett, 2008). Commercial-in-Confidence Page 20 of 74
Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
Due to the extensive areas of the EVC Lignum Swamp and its associated aquatic Tangled Lignum, Middle Reedy Lake supports a large Ibis breeding rookery. A total of 13 colonial breeding events have been recorded at Middle Reedy Lake between 1980 and 2013. This is the highest number of events in all of the KLBIP wetlands and includes species such as Australian White Ibis (Threskiornis molucca ), Royal Spoonbill (Platalea regia ), Straw-necked Ibis ( Threskiornis spinicollis ), Yellow Spoonbill ( Platalea flavipes ) and one Little Pied Cormorant ( Microcarbo melanoleucos ) event in 2000. The wetland is part of the Reedy Lakes system that supports 10% of the regional 5 breeding population of Straw-necked Ibis and Australia White Ibis and more than 5% of the Victorian breeding population of Royal Spoonbill (Clunie, 2010). In addition, Dusky Moorhen ( Gallinula tenebrosa), Purple Swamphen ( Porphyrio porphyrio ), Black Swan (Cygnus atratus ), Australasian Darter ( Anhinga novaehollandiae ), Australian Shelduck ( Tadora tadornoides ), Pacific Black Duck ( Anas superciliosa ) and the FFG listed White-bellied Sea Eagle ( Haliaeetus leucogaster ) have also been recorded breeding at the wetland (Clunie, 2010; KBR, 2011). Table 5 summarises the breeding events recorded for Middle Reedy Lake. Table 5: Bird breeding events at Middle Reedy Lake since 1985 Common Name Scientific Name Year
Australian White Ibis Threskiornis molucca 1985, 1988, 1993, 1998, 2001, 2003, 2005, 2013 Little Pied Cormorant Microcarbo melanoleucos 2000 Royal Spoonbill Platalea regia 1985, 1988, 2001, 2005, 2011, 2013 Straw-necked Ibis Threskiornis spinicollis 1985, 1988, 1991, 1993, 1998, 2003, 2005 Yellow Spoonbill Platalea flavipes 1987, 1991 Dusky Moorhen Gallinula tenebrosa 1988 Purple Swamphen Porphyrio porphyrio 1988, 1990 Black Swan Cygnus atratus 1988, 1990 Australasian Darter Anhinga novaehollandiae 1987 Australian Shelduck Tadora tadornoides 1988 Pacific Black Duck Anas superciliosa 1988 White-bellied Sea Eagle Haliaeetus leucogaster 1995 Source: BirdLife Australia, 2013; DEPI, 2013; Clunie, 2010; KBR, 2011. Of all the waterbird species recorded at Middle Reedy Lake, 37% are considered fish-eating, with shoreline foragers the second most abundant (21%). An analysis by SKM (2010) revealed that compared to the other KLBIP wetlands, Middle Reedy Lake is the highest for species richness, number of threatened species and listed migratory species, number of breeding events and breeding species. In the survey by Biosis (2013) a total of 30 individual Royal Spoonbills were observed loafing near the rookery on the western side of the wetland. This was the largest group of threatened birds observed during the study. The high abundance and species diversity is attributed to the highly complex nature of the wetland and the extensive areas of Tangled Lignum and other habitat features such as submerged logs and vegetation. This habitat was also found to support both Murray River Turtle ( Emydura macquarii) and Common Long-necked Turtle ( Chelodina longicollis ) and a total of five frog species which use the submerged vegetation for feeding and breeding (Biosis, 2013). In a ranking exercise undertaken by SKM (2010), Middle Reedy Lake was rated the highest for frog species richness and the third highest for turtle relative abundance compared to the other KLBIP wetlands. Compared to the other KLBIP wetlands, Middle Reedy Lake has moderate relative abundance, species and number of threatened fish species (Ho et al. 2006). A total of six native fish species which are listed as significant have been recorded at Middle Reedy Lake, including FFG and EPBC listed Murray Cod
5 The term ‘regional’ is not ecological meaningful and regional boundaries have changed numerous times in a departmental context since 1982. Commercial-in-Confidence Page 21 of 74
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(Maccullochella peelii ) and Murray Hardyhead ( Craterocephalus fluviatilis). Due to recreational fish stocking of Murray Cod and Golden Perch ( Macquaria ambigua) in neighbouring First Reedy Lake, there is a potential that these populations are not naturally occurring (DEPI, 2012). Regardless of the origin, Murray Cod will trigger the Environmental Effects Act 1978 ; however Golden Perch needs to be considered a natural occurring population. A study at First Reedy Lake by Hunt et al. (2010) revealed that stocked Golden Perch contributes to 47% of the population. It is therefore inconclusive as to the nativeness of the population in Middle Reedy Lake. The one individual Murray Hardyhead caught during the Biosis (2013) survey was a significant find being the first confirmed record of the species in the KLBIP wetlands. In Victoria, the species is considered extinct at eleven out of the 14 historical sites and there are now three known sites in the North Central CMA region (Stoessel, 2012). The species is usually found in sites with a salinity level between ~25,000- 50,000 EC, which excludes its major predator Gambusia ( Gambusia holbrooki ) (Macumber, 2009). Interestingly, Gambusia was the most abundant species captured in Middle Reedy Lake, accounting for 70% of all individuals collected. It is thought that the extensive submerged vegetation may provide sufficient refuge for Murray Hardyhead (Biosis, 2013). Other native fish species recorded at Middle Reedy Lake include Australian Smelt ( Retropinna semoni ) and Flathead Gudgeon ( Philypnodon grandiceps ) (refer to Appendix C). Although not captured during the recent Biosis (2013) survey, an additional three FFG listed fish species have been recorded in Middle Reedy Lake in the past– Silver Perch ( Bidyanus bidyanus ) and Unspecked Hardyhead ( Craterocephalus stercusmuscarum fulvus ) in 2006 and Freshwater Catfish ( Tandanus tandanus) in 1981. Eighteen families of macroinvertebrates were also recorded during the recent Biosis (2013) survey, compared to 13 families in 2006. The macroinverbrates community was identified to be broadly comparable, with the exception of Mesoveliidae , a community that live solely on the surface of the water and are difficult to capture. As with Racecourse Lake the aquatic macroinvertebrate fauna includes a number of predators, although dragonflies and watermites have not yet been collected. Overall the invertebrate fauna collected at the site are indicative of a permanent freshwater system in reasonably good condition (R. Butcher, pers comm., 18 September 2013). Appendix C details the full list of macroinvertebrates recorded at Middle Reedy Lake. Table 6 shows the significant fauna species that have been recorded at Middle Reedy Lake.
Table 6: Significant fauna species recorded at Middle Reedy Lake Common Name Scientific Name Water Last Inter- IUCN EPBC FFG Victorian depend- record national Red status status Conservation ency 1 treaty List status Birds Blue-billed Duck Oxyura australis Y 1990 NT L EN Caspian Tern Hydroprogne caspia Y 2013 J/C LC M L NT Eastern Great Egret Ardea modesta Y 2009 J/C M L VU Freckled Duck Stictonetta naevosa Y 1999 LC L EN Grey-crowned Pomatostomus N 2013 LC L EN Babbler temporalis temporalis Gull-billed Tern Sterna nilotica Y 2006 LC L EN Hardhead Aythya australis Y 2011 LC VU Latham's Snipe Gallinago hardwickii Y 2003 LC NT Musk Duck Biziura lobata Y 2006 VU Nankeen Night Nycticorax caledonicus Y 1988 NT Heron hillii Commercial-in-Confidence Page 22 of 74
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Common Name Scientific Name Water Last Inter- IUCN EPBC FFG Victorian depend- record national Red status status Conservation ency 1 treaty List status Pied Cormorant Phalacrocorax varius Y 2013 LC NT Royal Spoonbill Platalea regia Y 2013 LC NT Spotted Harrier Circus assimilis N 2012 LC NT Whiskered Tern Chlidonias hybridus Y 2012 LC NT White-bellied Sea- Haliaeetus leucogaster Y 2013 C LC M L VU Eagle Fish Freshwater Catfish Tandanus tandanus Y 1981 L EN Craterocephalus Murray Hardyhead Y 2013 EN EN L CR fluviatilis Silver Perch Bidyanus bidyanus Y 2006 VU L VU Unspecked Craterocephalus Y 2006 L Hardyhead 2 stercusmuscarum fulvus Golden Perch Macquaria ambigua Y 2013 NT Murray Cod Maccullochella peelii Y 2013 CE VU L VU Reptiles Murray River Turtle Emydura macquarii Y 2013 L VU Common Long- Chelodina longicollis Y 2013 DD necked Turtle Significant fauna key: • Water dependency: Y- water dependent, N- not water dependent • International Treaty: J - JAMBA, C - CAMBA, R -ROKAMBA, B – BONN • IUCN: EX- Extinct, EW- extinct in the wild, CR- critically endangered, EN- endangered, VU- vulnerable, NT- near threatened, LC- least concern, DD- data deficient • EPBC status: VU – Vulnerable, EN- Endangered, M- Migratory • FFG status: L – Listed as Threatened, N – Nominated for listing but not yet listed • DSE status: CR – Critically Endangered, EN- Endangered, VU- Vulnerable, NT– Near Threatened, K- Poorly known, DD- data deficient 1Water Dependency advised by Significant Wetland Dependent Fauna Species spreadsheet supplied by DEPI (compiled by R. Loyn (birds), N. Clements (Reptiles), M. Scrogie (Frogs), P. Papas (Invertebrates), L. Lumsden (Mammals) and J. Kohen and T. Raadik (Fish)). 2Un-specked Hardyhead was not included in the April 2013 release of the Advisory List of Threatened Vertebrate Fauna in Victoria (DSE, 2013). The species has been reassessed as abundant across many locations within Victoria, however it is currently gazetted under FFG (October 2012) and management options that impact this species may trigger the Environmental Effects Act 1978 . 5.4. Representativeness and distinctiveness Middle Reedy Lake’s current wetland classification is permanent open water (Lugg et al. 1989) using the Victorian wetland classification system (Corrick and Norman, 1980). In the North Central CMA region the area of this wetland type has almost doubled in size since European occupation and this wetland type is now considered over represented in the landscape (North Central CMA, 2005). In the Kerang Wetlands Ramsar site, eight wetlands are currently classified as permanent open water. Due to their close proximity and connectivity, as a complex these wetlands are considered significant in the context of the Murray-Darling Drainage Division and nationally (R. Butcher (Water’s Edge Consulting) pers comm., 18 September 2013). DSE pre 1750s mapping predicts that Middle Reedy Lake would have originally been classified as a deep freshwater marsh, a wetland classification considered to be the most depleted of all wetland categories in Victoria. It has been estimated that approximately 70% of deep freshwater marsh has been lost since European settlement (DSE, 2010). Table 7 illustrates the area and proportion of Permanent open water across various defined landscapes and highlight the relative minor contribution of Middle Reedy Lake to the whole Kerang Wetland Ramsar site and the North Central CMA region.
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Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
Table 7: Current area of Permanent Open water across the landscape North Central region Kerang Wetlands Ramsar site Goulburn-Murray (9,938 ha) Irrigation District Permanent Open Water (ha) 28,360 3,840 48,330 Middle Reedy Lake (179 ha) 0.63% 4.66% 0.37% 5.5. Middle Reedy Lake in the Ramsar context As discussed in Section 3.1 the Kerang Wetlands Ramsar site satisfies Ramsar criterion 1, 2, 3, 4, 5 and 6. This pertains to the complex being representative of rare and/or unique wetland types, supporting vulnerable, endangered, critically endangered species or threatened ecological communities, supporting plant and animal species important for maintaining biological diversity in the biogeographic region as well as plant and or animal species at critical life stages, drought refuge and high waterbird numbers (DEWHA, 2008). Table 8 compares Middle Reedy Lake against the Kerang Ramsar Site in terms of likely Ramsar Criteria. As discussed in Section 5.4 the wetland type permanent open water has increased significantly since European occupation and on its own is not considered a rare or unique wetland type (DSE, 2010). However in the Kerang Wetlands Ramsar site this wetland type exists as a collective complex and is considered significant both at the Murray-Darling Drainage Division and national scale. As per Criterion 2, Middle Reedy Lake supports a number of vulnerable, endangered and/or critically endangered species with two EPBC listed (Murray Cod and Murray Hardyhead) and three significant IUCN listed water dependent species (Refer to Section 5.3). Further to this Middle Reedy Lake also fulfils the requirements of Criterion 3, contributing to the freshwater components of the overall biodiversity values of the Kerang Wetlands Ramsar site, particularly fish, reptiles, frogs, flora and waterbirds. Criterion 4 relates to the wetland supporting critical life stages of wetland dependent species. At the Kerang Wetland Ramsar site and Middle Reedy Lake this refers predominantly to supporting migratory waterbirds. Middle Reedy Lake supports three migratory species listed under international treaties (Section 5.3). Further to this Middle Reedy Lake is considered an important drought refuge for waterbirds and fish, being both a permanent freshwater wetland and being in close proximity to the Loddon River. Criterion 5 relates to supporting high numbers of waterbirds. Although it is unlikely that Middle Reedy Lake on its own can support enough waterbirds to meet Criterion 5, its habitat contributes significant to this criterion met by the Kerang Wetlands Ramsar Site as a whole. Criterion 6 is unlikely to be fulfilled at just First Reedy Lake as the site as a whole supports with the wetland being part of the Reedy Lakes that supports 10% of the regional breeding population of Straw-necked Ibis and Australia White Ibis and more than 5% of the Victorian breeding population of Royal Spoonbill (Clunie, 2010). Table 8: Middle Reedy Lake against Ramsar Criteria Kerang Middle Summarised criteria Ramsar site Reedy Lake 1. Containing representative, rare or unique wetland types o 2. Support vulnerable, endangered, or critically endangered species or threatened ecological communities 3. Support populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region. 4. Support populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region. 5. Regularly supports 20,000 or more waterbirds. o Commercial-in-Confidence Page 24 of 74
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6. Regularly support 1% of the individuals in a population of one species or subspecies of x waterbird. KEY: • - criterion fulfilled by site/ wetland • × - criterion not fulfilled site/ wetland • o - site makes a contribution to fulfilling the criterion as a whole 6. Hydrology Wetland hydrology is the most important determinant in the establishment and maintenance of wetland types and processes. It affects the chemical and physical aspects of a wetland, which in turn affects the type of values the wetland supports (DSE, 2005a). A wetland’s hydrology is determined by surface and groundwater inflows and outflows, in addition to precipitation and evapotranspiration (Mitsch and Gosselink, 2000 in DSE, 2005a). Duration, frequency and seasonality (timing) are the main components of the hydrologic regime for wetlands and rivers. 6.1. Natural regime According to DSE pre-1750s classifications, Middle Reedy Lake would originally have been a deep freshwater marsh. Flood water would have entered First Reedy Lake via Washpen Creek and sometimes Wandella Creek which are both fed by the Loddon River. From First Reedy Lake water would enter Middle Reedy Lake before travelling further northward to Third Reedy Lake (SKM, 2010). Flood frequency analysis by SKM (2010) revealed that historically the average recurrence interval for floods in the Loddon River that would have resulted in unregulated flows into the Reedy Lakes was one in two years with the maximum interval between events being four years. Most flood events that occurred would have provided enough water to fill all three of the Reedy Lakes. As Middle Reedy Lake is situated in the middle of the Reedy Lake Complex, it is likely that the wetland would have received less water than First Reedy Lake, but more than Third Reedy Lake. The bathymetry (Appendix E) and the dead tree mapping undertaken by Ho et al. (2006) support this theory, with an increase in dead tree cover correlated with decrease in depth with distance from the water source (Loddon River). This pattern is similar to what is observed at Lake Bael Bael and the connecting Avoca Marshes. Permanency decreases with distance from the Avoca River, with Third Marsh, the shallowest wetland, drying out every few years compared to Lake Bael Bael, the deepest, which remains almost permanently full. It is therefore likely that Middle Reedy Lake maintained a more semi-permanent regime compared to its neighbouring counterparts (SKM, 2010). Under natural conditions flooding would have been seasonal, generally in the cooler winter months in wet years, before slowing receding each year through evaporation and seepage. It is therefore likely that the wetland would have maintained a highly variable water level, drying periodically under consecutive years without flooding (SKM, 2010 and Rakali, 2013). 6.2. Historic/current water management Middle Reedy Lake is currently maintained as permanent wetland (maximum operating depth of 74.88m AHD) and is part of the Torrumbarry Irrigation water supply system. An outlet from Middle Reedy Lake is regulated to supply water to local irrigation areas. This water travels through Third Reedy Lake and its regulator to either the Torrumbarry No. 7 Channel or the Torrumbarry No. 1/7 Channel from which it supplies irrigators (SKM, 2010). Since its inclusion into the Torrumbarry Irrigation system in the 1920s, Middle Reedy Lake has remained inundated with minimal fluctuations in water level (on average 74.57-74.88m AHD) (SKM, 2010). Due to Commercial-in-Confidence Page 25 of 74
Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake the ibis rookery, a designated supply level has been held between August and December, through using Middle Reedy Lake regulator (KBR, 2007). Table 9 shows a range of water level percentiles based on data from June 1986 and May 2013 for Middle Reedy Lake (and connecting First Reedy Lake). The data shows that the wetland operates above 74.61m AHD 95% of the time, with a level of 74.82m AHD 50% of the time. Table 9: Middle Reedy Lake water level percentiles (June 1986 to May 2013) Percentile 5% 10% 25% 50% 75% 90% 95% Water level (m AHD) 74.61 74.65 74.75 74.82 74.86 74.89 74.91 Source : R. Stanton (G-MW), 2013 As per the other wetlands in the Reedy Lake complex, Middle Reedy Lake is held at full supply level between the 1 of August and the 31 of January. After this time the wetland is allowed to drawdown for irrigation purposes by up to 30cm. When the irrigation season ceases, the wetlands will drawdown further via evaporation and seepage (SKM, 2010). The watering cycle over the last ten years is shown in Table 10 . Table 10: Middle Reedy Lake wetting/drying calendar Year 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 Status W W W W W W W W W KEY : W-wet; D- dry 6.3. Trajectory for the environmental values of Middle Reedy Lake under current water regime Middle Reedy Lake was assessed by Lugg et al. (1989) as being a very high value wetland, mainly for its waterbird breeding rookery (refer to Section 5.3). Flow recommendations proposed by Lugg et al. (1989) included allowing the water level to fluctuate as much as possible and taking the wetland out of the irrigation system. The inclusion of Middle Reedy Lake into the Torrumbarry Irrigation System has altered the original vegetation and habitat. The wetland has been inundated on a near-permanent basis, leading to displacement of much of the original vegetation (Rakali, 2013). BLA (2007) described the KLBIP wetlands as in a ‘stable’ trend based on the premise that dramatic change has already occurred within these wetlands. Rakali (2013) compared the 2006 and 2013 wetland vegetation mapping and concluded that: • Areas of Aquatic Herbland on the north western side of the wetland appear to have decreased significantly and some areas replaced by Tall Marsh. • Potential expansion in the distribution of River Club Sedge in the western edge of the wetland. As identified in Plates 1 and 2 in Section 5.2, Lignum areas (permanently inundated) that were once dense and discrete have spread out and dying in the centre. Rakali (2013) cautioned that if the Lignum continues on this path, it will eventually run out of suitable habitat. Under a suitable wetting and drying regime both Tangled Lignum and River Red Gums will regenerate from seed, providing more suitable habitat in the long term. The individual Murray Hardyhead collected in the wetland in the 2013 survey is also significant and further surveys are required to understand their status and requirement for ongoing management. Future changes to the hydrological regime of Middle Reedy Lake has the potential to introduce both positive and negative ecological consequences as discussed in Section 7.
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6.4. Alternative Water Regime Scenarios for Middle Reedy Lake Drawing on previous work by SKM (2010) and KBR (2011), the North Central CMA (2012) developed alternative wetland watering regime scenarios for all of the five KLBIP wetlands. The process for developing alternative wetland water regime scenarios has been informed by consideration of watering requirements for environmental values and wetland water regime definitions. The proposed water regimes that were identified and modelled for Middle Reedy Lake are presented in Table 11. Table 11: Middle Reedy Lake proposed watering regime scenarios (North Central CMA, 2012) Wetland type 1 Regime Frequency of wetting : 1 in 2 years Timing : Winter/Spring Depth: Dry- episodic Yr 1 – to maximum depth of 74.85m AHD Yr 2 -4 – no fill Duration: 1 to 4 months (allowed to dry naturally) Frequency of wetting : 1 in 4 years Timing: Winter/Spring filling Depth: Deep Freshwater Marsh- intermittent Yr 1 – 74.85m AHD Yr 2-3 – 73.85m AHD Yr 4 – no fill Duration: maintain at 73.85m AHD
Frequency of wetting: 9 in 10 years Timing: Fill Winter/Spring Open Freshwater Lake- semi-permanent Depth: 74.85m AHD Duration: allow evaporation to 74.45m AHD two years in a row
Open Freshwater Lake- permanent No change 1Wetland types are based on Brock et al. 2003: • Episodic- Wetland alternates between holding water and being completely dry, with the dry phase being the usual state; flooding occurs rarely and irregularly; surface water persists for months • Intermittent- Wetland alternates between holding water and being completely dry, but not annually as in seasonal wetlands; surface water persists for months to years • Semi- permanent- Wetland usually holds some water, with annual inflows being equal to or exceeding minimum losses in 90 per cent of years; surface water persists for decades, only drying out in extreme droughts Hydrological modelling for each watering regime was undertaken to estimate long term losses so that the water savings potential of the bypass intervention could be estimated. The modelling also predicted the long-term daily water level regimes under a range of possible operational regimes so that wetland potential for ecological rehabilitation can be evaluated, and the regimes refined accordingly (Fluvial Systems, 2012). A summary of the results is provided in Table 12 and shown in Figure 7. Table 12: Middle Reedy Lake modelling results (Fluvial Systems, 2012) Watering regime scenario Hydrological model setting Period wetland is dry Dry- episodic 1 in 2 years to 74.85m AHD 1 3 – 6 months 3 in 4 years, Year 1 to 74.85m AHD 1; Deep Freshwater Marsh- intermittent Six months Year 2 and 3 to 73.85m AHD 8 in 10 years to 74.85 1 – 74.45m AHD. Near complete drawdown (up to 6 Open Freshwater Lake- semi-permanent Drawdown over a two year period. months) 9 in 10 years to 74.85 1- 74.45m AHD. Fluctuations at the littoral zone. Open Freshwater Lake- semi-permanent Allow drawdown over a one year period. Wetland does not fully drawdown. Open Freshwater Lake- permanent Not applicable Never 1FSL recorded as 74.85m AHD; however connecting First Reedy Lake has a FSL of 74.88m AHD. An elevation of 74.85m AHD was modelled for the future scenarios, and 74.88m AHD for the current scenario.
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Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
Dry- episodic
Deep Freshwater Marsh- intermittent
Open Freshwater Lake- semi- permanent (8 in 10)
Open Freshwater Lake- semi- permanent (9 in 10)
Open Freshwater Lake- permanent
Figure 7: Predicted water levels under each proposed regime (Gippel, 2013)
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Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
6.5. Groundwater URS (2013) undertook a Hydrogeological Salinity Risk Analysis for the KLBIP using groundwater monitoring based on a Monte Carlo simulation technique. This analysis considered the salinity risk of four alternative water regimes as described in Section 6.4 and Table 11. Six bores located around and within 1 kilometre of Middle Reedy Lake were selected to assess the groundwater levels and potential for surrounding groundwater to be discharged into the wetland if its levels were reduced. Average salinity levels for Middle Reedy Lake typically range from 150 to 1,700 EC (G-MW, 2010). The data periods for the assessment is limited, for example bore 58547/58564 have a data period of 1988 to 2012 with a total of 287 data points. The findings of the hydrogeological data review are summarised in Table 13 below. Table 13: Middle Reedy Lake Groundwater Risk Assessment (URS, 2013) Watering regime Hydrogeological Risk Assessment Salt risk rating 6 scenario Has the greatest salinity risk with 80th percentile 7 Middle Reedy Lake Dry- episodic High (slightly saline) salinities estimated to increase to 7,132 EC upon refilling. Deep Freshwater Marsh- Relatively low salinity risk with 80th percentile Middle Reedy Lake salinities Low (very fresh) intermittent of less than 700 EC upon refilling. Open Freshwater Lake- Relatively moderate salinity risk with 80th percentile Middle Reedy Lake Low (very fresh) semi-permanent salinities of less than 769 EC upon refilling. Current operating levels are generally above the surrounding groundwater Permanent Open levels for much of the time, therefore acting as barriers to brackish Low (very fresh) Freshwater Lake groundwater flow. URS (2013) concluded that it is possible that surrounding groundwater could be discharged into Middle Lake if its levels were reduced. There are potential salinity risks when surrounding saline groundwater is higher than the wetland level creating a hydraulic gradient towards the wetland. The current operating levels are generally above the surrounding groundwater levels for much of the time, therefore acting as a barrier to brackish groundwater inflow. The episodic watering scenario presents the greatest risk for saline groundwater discharge into Middle Reedy Lake. With the exception of Little Lake Charm, the episodic watering scenario presents the greatest risk for Middle Reedy Lake. Risks of groundwater inflow are markedly reduced under the intermittent filling scenario. URS (2013) have suggested that salinity risk can be reduced in all cases by: • reducing the duration when wetland levels are low (or absent) especially times when surrounding groundwater levels are elevated (following sustained years of average or above, rainfall)
• reducing the depth to which wetland levels are reduced between filling phases. 7. Rationale for recommend water regime The risks and benefits associated with each of the wetland watering regime scenarios developed for Middle Reedy Lake have been assessed with regards to the wetland’s Ramsar criteria, threatened species, EVCs, Salinity and Acid Sulphate Soils (ASS). The below section outlines the findings of the assessment with Table 14 summarising whether each watering regime provides a benefit, impact, no
6Risk rating based on salt tolerances for wetlands: Very Fresh = up to 1500 EC, Fresh = 1,500 to 4,500, Slightly saline = 4,500 to 15,000, Saline = 15,000 to 52,000 (Roberts and Marston, 2011).
7Percentile: indicates the value below which a given percentage of observations in a group of observations fall. For example, 80th percentile is the value below which 80 percent of the observations may be found. Commercial-in-Confidence Page 29 of 74
Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake change or if additional investigations are required. Section 7 assists in refining the recommended water regime and is used to support the more detailed objective setting and water regime recommendations outlined in Section 8. Ramsar Criteria As identified in Section 3.1 the Kerang Wetlands Ramsar site satisfies the criteria associated with being a representative, rare or unique example of a wetland type (Criterion 1). The site encompasses six of the eight Victorian wetland categories; however Middle Reedy Lake is described as a Permanent Open Freshwater wetland, a classification which on its own is not considered rare. The original (pre 1750s) classification, Deep Freshwater Marsh, is characteristic of a more variable and drier water regime and subsequently would have supported a more biological diverse (Criterion 3) assemblage of flora and fauna compared to the current permanent conditions. However as identified in Section 5.5, the presence of Tangled Lignum in permanent water, contributes significantly to supporting waterbirds and to meeting Ramsar criteria 5 and 6. The impact of a changed regime on this habitat anomaly needs to be further investigated to determine the potential impact on the sites Ramsar listing (refer to Section 7: EVCs/Flora). Birds Species Middle Reedy Lake supports a high diversity and abundance of waterbird species with 15 species considered significant and 12 species recorded as breeding in the wetland since 1985 (refer to Section 5.3). The majority of these breeding events are facilitated by the extensive areas of Tangled Lignum and as a result Middle Reedy Lake is considered an important Ibis breeding rookery. It is commonly accepted that the provision of a more natural wetting and drying regime will facilitate an increase in habitat diversity, bird roosting, feeding and breeding opportunities and promote regeneration. At Middle Reedy Lake it is likely that increased seasonality in water level will encourage a more diverse range of flora and fauna species particularly in the littoral and drawdown. Evidence further suggests that the permanent regime has resulted in a deterioration of the Tangled Lignum community as well as areas of Aquatic Herbland. However, due to the abnormality of this Tangled Lignum (i.e. its ability to persist in permanent water) and the importance in satisfying waterbird related Ramsar criteria, there is a risk that a drying regime may also accelerate the loss of the species. Further research is required to determine the impacts and benefits of maintaining both permanent conditions and promoting fluctuations. Fish Species Middle Reedy Lake has moderate abundance, species and number of threatened fish species including Murray Cod and Murray Hardyhead. The Murray Hardyhead record is potentially significant with the 2013 catch being the first confirmed record of the species in the Kerang Lakes system. Therefore Middle Reedy Lake is a potential refuge site for Murray Hardyhead (nationally listed native fish species). Successful management of Murray Hardyhead requires permanent conditions, with ample aquatic vegetation and exclusion of predators such as Gambusia. A Murray Hardyhead Recovery Plan (Victoria) has been established and has the overall objective of minimising the probability of species extinction in the wild whilst increasing the chances of its population becoming self-sustaining for the future. Translocation sites are currently being established with at least one extra population planned for the Kerang and Mildura districts. Further investigations into the status of Murray Hardyhead at Middle Reedy Lake are required to determine the wetlands long term suitability for maintaining the species.
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Reptiles (Frogs / Turtles) Species Middle Reedy Lake supports both Murray River Turtle and Common Long-necked Turtle and a total of seven frog species which use the submerged vegetation for feeding and breeding. The Murray River Turtle, which is listed as vulnerable in Victoria tends to favour permanent watering regimes however there is the potential for the species to move to more favourable conditions (Beesley, 2013). However, Common Long-necked Turtles, which are also listed with a Victorian conservation status, prefer ephemeral backwaters (Howard et al. 2013). Further monitoring is recommended to determine the status of turtles and frogs at Middle Reedy Lake and how a changed regime may impact on these populations in the future. EVCs/Flora The narrow distribution and extent of the littoral EVCs (i.e. Tall Marsh and Aquatic Herbland) of Middle Reedy Lake is the direct result of the wetlands permanent regime. The potential benefits of periodic wetting and drying may include regeneration of and improvement in the diversity in Middle Reedy Lake’s vegetation communities and subsequently and improvement in the quality of habitat for native fauna. However it is unknown as to how the important Tangled Lignum community will respond to a changed regime. Further work is required to understand the current health and life cycle of the Tangled Lignum community of Middle Reedy Lake and investigate viable options to maintain and if possible, improve this important habitat for the future. Salinity / Acid Sulphate Soils The hydrogeology study has indicated that there are some salinity and Acid Sulfate Soils (ASS) risks associated with instigating a drying regime, with the greatest risks ranging from the episodic through to the lowest risk of no change. If ASS are present, partial drying to complete drying of the wetland bed will expose sediments which may either contain sulfuric acid (sulfuric material), or have the potential to form sulfuric acid (sulfidic material), or cause de-oxygenation (monosulfidic material), or release contaminants when the sulfide materials are exposed to air (MDBA, 2010). This can potentially impact on the aquatic environment (flora and fauna values), water supply, infrastructure and public health. Additional investigations are required at Middle Reedy Lake to assess the impact of partially drying of the littoral zone, including an analysis of soil pH. The study also indicates that regional groundwater levels need to be taken into account when managing the water regime of Middle Reedy Lake to minimise the risk of saline groundwater intrusion (URS, 2013) as discussed in Section 6.5. Overall summary Middle Reedy Lake is a high value wetland especially due to the presence of Tangled Lignum habitat within permanent water. However, since European settlement the wetland has changed dramatically and now supports a suite of flora and fauna species adapted to stable, permanently high water levels. There is however the potential to significantly improve much of the habitat values of Middle Reedy Lake through promoting an appropriate wetting and drying regime. This would align more closely with the wetlands natural behaviour and promote a more diverse assemblage of flora in the drawdown and littoral zones. However the presence of Tangled Lignum in permanent water is an abnormality and little research has been undertaken on watering requirements of the species. Evidence suggests that the Commercial-in-Confidence Page 31 of 74
Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake community may be deteriorating; however without any supporting research, a changed regime may actually cause an accelerated loss of the species and subsequently impact significantly on the ability of the wetland to support colonial nesting waterbirds. Further to this, the status of Murray Hardyhead needs to be determined before the regime is modified to establish its ability to support the species in the future and further ASS, frog and turtle investigations are also required. Table 14 summarise the information supplied in Section 7 by indicating the likely impact of each regime on the key values. Please note that the symbols used do not aim to quantify the degree of changed expected (i.e. low benefit compare to a high benefit), instead are simply used to indicate the predicted nature of the change (i.e. positive or negative). The table indicates that the preferred regime for Middle Reedy Lake based on this information, falls between the description of semi-permanent and permanent regime (as per Table 11). This implies that the regime should not remain the same (as per the regime description of no change/ permanent open freshwater lake) however should also not include a complete dry (as per the description of open freshwater lake/ semi-permanent). Section 8 further expands on this information by exploring the management objectives and more clearly defines the preferred water regime for Middle Reedy Lake. Table 14: Risk assessment associated with each watering regime scenario at Middle Reedy Lake Biota Ramsar EVCs / Water regime scenario Frogs / Salinity ASS Criteria Birds Fish flora turtles Dry- episodic / Deep Freshwater Marsh- - intermittent Open Freshwater Lake- semi- - permanent No Change - Permanent Open - - - - Freshwater Lake KEY: Benefit - No change expected o Additional investigations, management required Negative impact likely TBC Waiting for results from the Socio-economic study (RMCG 2013)
8. Management objectives As Middle Reedy Lake is used for water supply it is currently maintained permanently full. Table 15 outlines the previous management objectives that have been recommended for Middle Reedy Lake.
Table 15: Previous management considerations Source Objectives Recommendation • Water level be allowed to fluctuate as much as possible Lugg et al. Manage as a semi-permanent wetland • Monitor lignum, surrounding vegetation and viability of 1989 rookery To provide a watering regime that maintains the existing habitat types, in particular the depleted EVC Lignum Swampy Woodland • Wetting one in one to two years (variable duration of up to 4 SKM, 2010 and areas of open water that together months) provide habitat for a high abundance and diverse range of waterbirds. KBR, 2011 Maintain current ecological condition of • Maintain at or near fully supply level with annual fluctuations (draft) littoral zone
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8.1. Management goal The overall management goal for Middle Reedy Lake is based on the information presented above including consideration for the ecological values (current and future) and the wetland’s natural regime.
Middle Reedy Lake goal To provide a permanent regime that introduces seasonal variability to the water level at the littoral zone, creating drawdown zones, promoting growth and increased health of Tangled Lignum as well as the re- establishment of submerged and floating macrophytes throughout the wetland. This will promote improved conditions for colonial nesting waterbirds and increased opportunities for turtles, frogs and fish.
8.2. Ecological and hydrological objectives Ecological objectives for Middle Reedy Lake represent the desired ecological outcome for the wetland and were developed to determine the optimum watering regime for the wetland to protect and promote high ecological values. Table 16 considers the ecological values of Middle Reedy Lake (Appendix C) and sets a range of ecological objectives and trajectories based on managing for the goal proposed in Section 8.1. Please note that Table 16 considers the full suite of ecological objectives for First Reedy Lake and accordingly, these objectives will be refined should an Environmental Water Plan be developed. Table 16: Proposed ecological objectives for Middle Reedy Lake
Ecological objective Justification Hydrological requirement
Habitat objectives Open water zone supports long term fish Inundate and allow fluctuations in water level to 1.1 Maintain permanent populations and deep water foraging stimulate drawdown zone habitat (i.e. mud zones) open water and water birds. Drawdown zones supports (DSE, 2012b). Maintain minimum depth of ~1m drawdown zones foraging waterbirds. Also provide reliable through summer to ensure temperature is adequate source of water for turtles and frogs. for most large bodied fish (Water Technology, 2007). 1.2 Increase/ restore Annual inundation (once in up to three years is also Sedges and rushes provide important diversity o f aquatic tolerable) at 0.3-1.5m in depth for eight to 12 waterbird roosting, feeding and nesting vegetation (i.e. months at a time (broad requirements, with specific habitat (also shelter for small native fish sedges, rushes, requirements dependent on species). Flooding i.e. Murray Hardyhead), filter water and submerged/ floating preferable in autumn and winter (Roberts and adding biological activity. macrophytes) Marston, 2011). Breeding habitat for waterbirds Generally one in every three year (can be less (particularly colonial nesters- White Ibis, 1.3 Maintain diversity frequent but lignum will lose structural integrity for Straw-necked Ibis and Royal Spoonbill), and health of shrubs nesting) for 3-7 months at depths of up to 1m sanctuary for waterfowl, fish and aquatic (e.g. Tangled (Roberts and Marston, 2011). However community invertebrates. Lignum is also effective at Lignum) is an anomaly and little information is available on catching silt and debris (Price Merrett, hydrological requirements. 2008). Supports waterbird breeding (nests, Fill to full supply level (74.88m AHD) in late winter or 1.4 Maintain health and hollows, fallen timber etc). Also provides early spring one in every one to three years for extent River Red shade to instream habitat and source of duration of five to seven months (Roberts and Gum trees seed for recruitment. Marston, 2011). Species/community objectives 1.1 Maintain and/or Maintain permanent inundation (with fluctuation). Provide a diversity of aquatic habitat types promote conditions Minimum depth estimated at 1m for large bodied and food sources to supports range of suitable for native fish (to maintain a tolerable temperature) (Water native fish species (particularly significant fish species Technology, 2007). Rising water levels are also species) as well maintenance of (particularly Murray known to promote native fish breeding (DCFL, 1989 permanent open water. Hardyhead) in DSE, 2004).
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Ecological objective Justification Hydrological requirement
1.2 Improve waterbird breeding Provide a range of habitat types suitable Some waterbirds require flooding cues to stimulating opportunities for waterbird nesting, resting and breeding. Permanent regime preferred. (particularly colonial breeding. nesters) 1.3 Improve waterbird Provision of a range of terrestrial and Provide suitable habitat as per habitat objectives feeding aquatic food sources including insects, ensuring slow recession of water level. opportunities macros, fish, algae and plant matter. Provide a diversity of habitat types as well 1.4 Maintain and/or as feeding opportunities to promote turtle promote turtle and Expose shallower areas to promote diversity of and frog use (particularly increase in Tall frog feeding and aquatic plants for feeding opportunities. Marsh habitat at north western corner of breeding wetland). Process objectives 1.5 Maintain Facilitates dispersal of seeds, micro and Ensure connectivity remains under modernisation. connectivity macro organisms, fish, frogs and turtles. Ensure water regimes are managed across all three between KLBIP Also maintains water quality through Reedy Lakes to ensure dispersal can take place. wetlands exchange of water. A diversity of biological and chemical 1.6 Restore ecological process will increase productivity by process at littoral exposing the important drawdown zones, zone associated with Some fluctuation in water level at littoral zone allowing seed germination, aeration of fluctuating water (specific requirements dependent on species). sediments, and an increase in organic levels (i.e. increase matter input as well as promoting a productivity) variety of habitat types. Source : Barker et al. 1995; Rogers and Ralph, 2011; Roberts and Marston, 2011; DSE, 2012a; DSE, 2012b; Biosis, 2013; Rakali, 2013 8.3. Proposed water regime Based on the supporting ecological values and subsequent defined ecological and hydrological objectives for Middle Reedy Lake, a wetland water regime has been derived and is outlined below. Adaptive management 8 will be integrated into the management of Middle Reedy Lake to counter any potential adverse risks. Figure 7 and Figure 9 shows a schematic cross section to illustrate the various components of the wetland under the proposed water regime while Appendix A shows expected exposed area.
Timing: Fresh inflows in late winter early spring
Frequency of Minimum: Annual regime (permanent regime- allow season fluctuations wetting: between 74.88 and 74.33m AHD (1.6m depth) to expose small portion of Tangled Lignum zone
Optimum/ maximum: Annual regime (permanent regime- allow seasonal fluctuations between 74.88 and 74.57m AHD)
8 Adaptive management: A systematic process for continually improving management policies and practices by learning from the outcomes of previously employed policies and practices. Commercial-in-Confidence Page 34 of 74
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Duration: Variable depending on habitat however: • Fringing zone - Riverine Chenopod Woodland/ Intermittent Swampy Woodland/ Lignum Swampy Woodland/ Lignum Shrubland/ Saltmarsh-grass Swamp o Approximately 3 to 8 months of inundation • Littoral / photic zone - Tall Marsh/ Lignum Swamp/ Aquatic Herbland o 1 to 8 months of inundation o 3-7 months preferred for Tangled Lignum • Open water zone - containing submerged Aquatic Herbland (predominately open water with some benthic herbs) o >8 years of inundation (almost never dries) Extent and depth: • Fringing zone - 0.3-1m in depth • Littoral/ photic zone - <0.3m-2m in depth (> 1m preferred for Tangled Lignum) • Open water zone- variable o Benthic herbs- 0.3-1m • Maintain seasonal variability in water level between 74.88m AHD (2.04m/ FSL) and a minimum depth of 74.57m AHD (~1.7m) • Rate of rise and fall 5cm per day (Tucker et al. 2002) Variability: Moderate
The regime at Middle Reedy Lake will focus on:
Long term management: To provide a watering regime that reintroduces variability in the water level at the littoral zone of Middle Reedy Lake, promoting an increase in the extent and health of Tangled Lignum as well as re- establishment of submerged and floating macrophytes. Provide fresh inflows annually to maintain a variable depth of between 74.88m AHD (FSL) and 74.57m AHD (1.7m depth).
The above proposed regime is on the conservative side of ensuring no dramatic change to the Tangled Lignum community of Middle Reedy Lake. It is worth considering the option of allowing an increased fluctuation range i.e. to 74.33m AHD (1.6m maximum depth) which would expose a small portion of the 0.6ha patch of Tangled Lignum at the south-west of the wetland. The theory that low level or some drying may be beneficial to the Tangled Lignum community is effectively being tested under the proposed regime at First Reedy Lake, where two patches will be exposed to varying inundation depths (one will be almost fully exposed and the other will have around 40cm of water depth). Observations at First Reedy Lake may play an important part in the future management of the Middle Reedy Lake. It should be noted that implementation of the preferred watering regime should occur gradually (i.e. made over 5-10 years) to ensure sufficient time for the targeted ecological values to respond. An adaptive management program will need to be implemented as part of the Environmental Watering Plan that needs to be developed. Appendix A shows the indicative drawdown zone under the preferred regime.
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Figure 8: A conceptual cross section of Middle Reedy Lake under proposed regime. Insert map shows cross section position (image not to scale).
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Figure 9: A conceptual model of the littoral zone of Middle Reedy Lake as marked in Figure 8 (red) under the proposed regime .
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9. Potential Risk, Adverse Impacts and Benefits 9.1. Impact to current Ramsar Criteria The national guidelines for Ramsar wetlands advise that under the convention, Australia is obliged to provide a notification of change for “human-induced adverse alteration” (DEWHA, 2009). This concerns change to ecological character rather than the change to the criteria for which it was listed. The current ecological character description was prepared in 2006 (DSE, 2006). The proposed water regime at Middle Reedy Lake will not result in a ‘human induced’ change to the ecological character; as the wetland will remain a permanent wetland. However, increased water level variability will increase frog, fish, turtle and waterbird use, particularly feeding opportunities in the littoral/drawdown zones as well as breeding opportunities through improved health of the Tangled Lignum community. Maintaining a permanent regime will also continue to allow the wetland to act as a drought refuge in the landscape, particularly during drying years. Table 17 compares the current regime to the likely outcomes of the optimum regime in terms of compliance with Ramsar criteria. Table 17: Current vs. proposed water regime Ramsar criteria compliance for Middle Reedy Lake Current Optimum Summarised criteria regime Regime
1. Containing representative, rare or unique wetland types o o
2. Supports vulnerable, endangered, or critically endangered species or threatened ecological communities 3. Support populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region. 4. Support plant and/or animal species at a critical stage in their life cycles, or provides refuge during adverse conditions.
5. Regularly supports 20,000 or more waterbirds. o o
6. Regularly support 1% of the individuals in a population of one species or subspecies of x × waterbird. KEY: • - criterion fulfilled by site/ wetland • ×- criterion not fulfilled by site/ wetland • o- site makes a contribution to fulfilling the criterion as a whole 9.2. Risk and benefit assessment The risk and benefit assessment methodology adopted for this project is based on the US EPA Guidelines for Ecological Risk Assessment (US EPA 1998 in Ecological Associates, 2010) as utilised in Ecological Associates (2010). This methodology uses the same principles and steps as the Australian/New Zealand Standard for Risk Assessment (AS/ NZS ISO 31000). A qualitative benefit and risk assessment has been undertaken to assign the ecological effect of implementing the recommended environmental watering regime. The benefit and risk matrices used to assign the levels of benefit and risk is provided below. The benefit component has the objective of assessing the benefit of the water regime on the ecological objectives developed in Table 16 . The relationship between exposure (probability of occurrence) and the ecological effect (ability to meet the ecological objective) provide the basis for evaluating the level of benefit (Table 18). The results for the benefit assessment are presented in Table 20 .
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Table 18: Benefit matrix Benefit Matrix Ecological Effect Fails to meet Partially meets Meets Exceeds objectives objectives objectives objectives Low Very low Very low Low Moderate Remote/ weak/ insignificant extent Minor Very low Low Moderate High Rare/ mild/ localised Moderate Low Moderate High Very high Exposure Exposure Common/ strong/ broad Strong Moderate High Very high Very high Frequent/ intense/ extensive Benefit Description Very low There is little to no benefit to the ecological objective.
Low Moderate benefit to the ecological objective.
Moderate There is a reasonable benefit to the ecological objective.
High There is a considerable benefit to the ecological objective. Very High The benefit on the ecological objective is considered very high. The risk component aims to assess the ecological risk associated with the proposed water regime and considers a range of endpoints that describe and represent all the significant ways that the ecological objective might be enhanced or degraded by the water regime. The relationship between exposure (probability of occurrence) and the ecological effect (severity of the impact) provide the basis for evaluating the level of risk (Table 19). The results for the risk assessment are presented in Table 21 . Table 19: Risk matrix Risk Matrix Ecological Effects Very minor Minor Moderate Severe Very low Remotely likely/ weak/ insignificant Very low Very low Low Moderate spatial extent Low Rare/ mild/ occurs in a Very low Low Low Moderate localised/patchy spatial extent Moderate Exposure Exposure Low Low Moderate High Common/ intense/ occurs broadly High Frequent/ constant/ intense/ Moderate Moderate High Very high widespread Risk Description Very low No reasonable prospect that the objective will be affected by the event. Low Low priority for management by the benefits of the project could be increased by mitigation. The risk has the potential to significantly reduce the benefits of the project but it is not likely to cause Moderate significant environmental harm. There is a reasonable likelihood it will occur and will have harmful consequences or objectives will be High significantly compromised. Risk management is essential.
Very high The risk is likely to occur and will have very harmful consequences. Risk management is essential. Section 9.3 details the mitigation measures relevant for the moderate to very high level risks identified for Middle Reedy Lake. The risk rating has then revised based on implementing the identified mitigation measures and using the same risk matrix in Table 19 above.
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Table 20: Benefit assessment for the objective of restoring seasonal variability at the littoral zone to promote Tangled Lignum and re-establishment of submerged and floating macrophytes at Middle Reedy Lake. Ecological objective Stressor Benefit description Exposure Ecological effect Benefit rating Description of objective Component of the regime Potential improvement in current Likelihood that the regime will provide The degree to which the ecological The that potentially impact on state of the ecosystem the environmental conditions to support objectives are met significance of the ecological objective the benefit the benefit Habitat 1. Maintain Permanency of water as Currently the small fluctuation in Minor- The regime will reintroduce Meets objectives - the regime will Moderate permanent open well as fluctuations in level water level supports only a few small seasonal patterns to the current regime return seasonality to the water level water and at the littoral zone. pockets of drawdown habitat and specifically in the littoral zone. However mimicking more natural fluctuations. associated large areas of open water (Biosis, the regime proposes the same range of This should correspond with the drawdown zones 2013). Drawdown zones are highly fluctuations as current operations and germination requirements of seeds and productive environments, incubating therefore a large change will not occur. propagates (Gawne and Scholz, 2006). eggs, allowing spores and seeds to The open water zone will continue to be germinate and providing an maintained at depths of 2.04- 1.7m in all important source of food for fauna. years to ensure adequate water to Open water provides important long maintain native fish populations (Gawne term habitat for fish and turtles and and Scholz, 2006). provides an important feeding ground for fish-eating waterbirds. 2. Increase/ Permanency of water as Extensive zones of aquatic herbs are Moderate - The water regime may allow Partially meets objective- the regime Moderate rehabilitate well as fluctuations in level found surrounding Tangled Lignum some expansion of aquatic vegetation should result in at least the diversity o f aquatic at the littoral zone. patches in the western region of the through mimicking more natural maintenance of the current aquatic vegetation (i.e. wetland. As the water depth seasonality. Fluctuations should allow vegetation assemblage, however due sedges, rushes, increases these herbs are more seeds (assuming existing plants are to minimal change in the regime large submerged and sparsely scattered (Rakali, 2013). viable) to be set during the drawdown changes are unlikely. floating These species are an important phase in the littoral zone and then macrophytes) substrate for epiphytic growth which flooded in winter-spring allowing provides an important food source germination (Roberts and Marston, for macroinvertebrates, birds, turtles 2013). and frogs. They also assist in filtering water and prevent algae dominance (Roberts and Marston, 2011). 3. Promote Fluctuations in water level Shrubs such as lignum provide Minor- The regime will return seasonal Partially meets objective- it is likely Low regeneration/ at littoral zone. important nesting, resting and variability to the littoral zone however that some regeneration may occur due growth of shrubs breeding habitat for waterbirds Tangled Lignum will still be inundated at to more natural seasonality; however a (i.e. Tangled (particularly colonial nesters such as similar level to the current management. significant increase in extent and Lignum) Australian White Ibis, Straw-necked density is not expected. Ibis and Royal Spoonbill as seen at Commercial-in-Confidence Page 40 of 74
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Ecological objective Stressor Benefit description Exposure Ecological effect Benefit rating Middle Reedy Lake) (Rogers and Ralph, 2012). It is also effective at catching silt and debris and provides a sanctuary for waterfowl fish and
aquatic invertebrates (Price Merrett, 2008). 4. Rehabilitate the Flooding and drying (at River Red Gums provides important Low- No major change to the current Partially meets objective - in most Very Low health and extent target zone) duration and nesting, resting and feeding (i.e. operations of the wetland. cases the River Red Gum zone is of River Red Gum frequency. insects) habitat for waterbirds and supported above the FSL and therefore trees raptors, shade for aquatic habitat changes to the water level will not and organic matter input. Patches of impact directly on these species. drowned River Red Gums in the However altering the seasonality of shallower zones of the wetland show water levels may allow seed that conditions would have establishment in the productive supported this species in the past. substrate of the drawdown zones. Species/communities 1. Maintain and/or Permanency of water as Fish require permanent water with Moderate- the regime will continue to Meets objective - The regime will High promote well as suitable habitat and appropriate aquatic vegetation for permanently maintain a minimum of maintain a permanent system, conditions suitable food sources. food feeding, breeding and nesting 1.73 m of water in all years. Some providing a refuge for native fish whilst for native fish (Rogers and Ralph, 2011). Rising seasonal drying at the littoral zone will promoting favourable conditions for species water levels are also known to promote feeding opportunities upon re- feeding and breeding (Roberts and (particularly promote native fish breeding (DCFL, flooding. Marston, 2011). Murray 1989 in DSE, 2004). Hardyhead) 2. Improve waterbird Timing, duration and depth Flooding acts as a stimulus for Minor - the regime may see an increase in Partially meets objectives- The regime Low breeding of flooding and drawdown breeding in most waterbirds if diversity at the littoral zone providing is unlikely to improve waterbird opportunities as well as habitat available habitat is appropriate. Appropriate more opportunities for waterbird breeding opportunities but will (particularly to support food source. habitat, water depth, timing and breeding. However the re-fill event in maintain current conditions through colonial nesters) duration of flooding and drawdown winter/spring may not be at a scale ensuring refuge conditions. will impact on success (Rogers and considered significant enough to cue Ralph, 2011). large scale waterbird breeding. 3. Improve waterbird Timing, duration and depth Variability in water level promotes Low - The regime will not result in a large Meets objectives- seasonal changes to Low feeding of flooding and drawdown productivity and an increase in food scale change to the current feeding the water level should correspond with opportunities as well as habitat available sources by increasing nutrients, opportunities at Middle Reedy Lake. waterbird feeding (i.e. fill in spring to support food source. organisms, insects, shoots and roots releasing nutrients, drawing down in (Rogers and Ralph, 2011). summer etc). 4. Maintain and/or Timing, duration and depth Frogs and turtles require a range of Moderate- Drawdown in littoral zone will Meets objective - the distribution of High promote turtle of flooding and drawdown terrestrial and aquatic habitat types follow more natural seasonality which sedges, rushes and shrubs (i.e. lignum)
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Ecological objective Stressor Benefit description Exposure Ecological effect Benefit rating and frog feeding as well as habitat diversity. from fallen timber to aquatic sedges should increase productivity. Open water will be maintained under the current and breeding and rushes and open water. They in will continue to support turtles. regime providing habitat for turtles and turn provide an important food frogs. source for waterbirds (particularly frogs) (Rogers and Ralph, 2011). Process 1. Maintain Flooding and drying (at Connectivity allows dispersal of Dependent on Bypass infrastructure. Refer to KBLIP Landscape Scale Consideration Unknown connectivity target zone) duration and seeds, micro and macroorganisms, Report (North Central CMA, 2014). between frequency. fish, frogs and turtles. Also maintains neighbouring water quality through exchange of wetlands (and the water. Loddon River) 2. Restore ecological Wetting and drawdown Drawdown at littoral zone will result Low - the regime will not result in a Partially meets objective- Seasonal Very low process at littoral phase (to minimum depth in the concentration of nutrients, significant change from the current ecological process associated with zone associated of 1.73m). organic matter, salts, nutrients and operations, but will introduce drying and wetting will be maintained with fluctuating organisms as well as facilitating seasonality. under proposed regime. water levels germination and growth of plants. This will increase germination, aeration of sediments and increase organic matter input Mitch and Gosselink, 2000; Gawne and Scholz, 2006).
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Table 21: Risk assessment for the objective of restoring variability at the littoral zone to promote Tangled Lignum and re-establishment of submerged and floating macrophytes at Middle Reedy Lake End Point Stressor Risk description Exposure Ecological effect Rating Indicator Aspects of the water Biological or physical effect of Exposure of the endpoint to the stressor Potential effect on the stressor on the endpoint Significance regime that potential the stressor on the endpoint of the risk affect the endpoint Habitat Permanent Reduced extent and • Reduction in extent and Low - the regime will return some seasonality Minor- The regime will not result in a significant change Low open water depth of flooding depth of open water zone to the current water level range. However this from the current open water and drawdown zones and • Increased turbidity upon will not result in a large scale change to the supported in the wetland. However productivity may associated rewetting of drawdown current depth and extent of open water at the increase due to fluctuations coinciding with natural drawdown zone wetland. seasonal patterns. zones Aquatic Reduced extent and • Poor health of some Low- the regime will not result in a significant Minor- it is expected that there will be no change from Low vegetation depth of flooding aquatic species due to change from the current operations of the the current condition of the wetland under the proposed change in depth, extent etc wetland. regime. • Death or displacement (i.e. desiccation, grazing) • monoculture Long history of • Lack of recruitment due to Moderate- long term permanent inundation Moderate- low abundance of aquatic vegetation Moderate inundation no/low existing seed bank with minimal fluctuation is likely to have (particularly in open water zone) recorded by Rakali • Establishment of exotic/ resulted in a loss of seed bank. (2013) suggests low seed stock. However seasonality competitive species may favour reestablishment of some species in the drawdown zone (Roberts and Marston, 2011). Shrubs (i.e. Variability in water • Over colonisation of some Low- it is unlikely that the water regime will Minor- it is expected that there will be no change from Low Tangled level as well as species cause a significant change to the shrub the current condition of the wetland under the proposed Lignum) reduced extent and • Reduction in some native assemblage currently supported at Middle regime. depth of flooding flora due to their Reedy Lake. dependency on permanent regime in littoral zone • Loss of highly valued Tangled Lignum community • Death or deterioration in health
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End Point Stressor Risk description Exposure Ecological effect Rating Long history of • Lack of recruitment due to High- long term permanent inundation with Moderate- severe- the regime will introduce some High- very inundation no/low existing seed bank minimal fluctuation is likely to have resulted in seasonality which may assist with support recruitment, high a loss of seed bank (particularly deeper into however the maintained high water level is unlikely to wetland). result in an improvement to the condition and extent of the Tangled Lignum community of Middle Reedy Lake. If the community continues to deteriorate there will be dramatic implications for the Ibis Rookery of the wetland. Black Box and Reduced flooding/ • Poor Black Box health due Low- water level does not currently extend Moderate – no improvement in the health of the Low Red Gums increased drying at to less flooding high enough to provide Black Box with the existing Black Box zone due its position above FSL trees fringe • Tree death appropriate water regime; therefore (except during unregulating flooding events). • Low/no recruitment fluctuations will not directly impact on this species. Other flora Impact of changed • Intermittent Swampy Very low- extensive areas of Intermittent Very minor- the regime should not negatively impact on Very low species regime on significant Woodland species Swampy Woodland currently exist at Middle these species; however it is also not anticipated to species (Branching Groundsel, Reedy Lake. It is unlikely that the regime will improve the area of occupation. Spiny Lignum and Flat-top facilitate an inward shift due to minimal Saltbush, Native Couch, fluctuations. Short Water-starwort, Twin-leaf Bedstraw, Salt Paperbark, Spreading Emu- bush) Weeds/ Promotion of • Establishment of Low - regime will result in a minor disturbance Minor- the current growth/spread of colonising species Low competitive competitive native competitive native (if any) to weeds and colonial species, and is is suppressed under the current regime. The proposed natives species or exotics (i.e. emergent species (i.e. over unlikely to impact on the current habitat of the regime is unlikely to change the current assemblage of monocultures) proliferation of native wetland. weeds. Typha, Phragmites) that suppress native species (reduced diversity) • Establishment of introduced species (i.e. Spiny Rush), either to become denser or colonise areas previously inundated (i.e. loss of open water) • Loss of grazing habitat for waterbirds
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Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
End Point Stressor Risk description Exposure Ecological effect Rating Species Waterbirds Changed regime • Reduction in area for deep Low- the regime will not result in a change Minor- it is anticipated that the regime will not result in Low impacting on food water foragers (open from the current feeding opportunities at the a change from the current feeding opportunities at the availability water) wetland. If anything the increased seasonality wetland. • Change in composition of may promote some improvement in littoral nesting/ resting habitat zone opportunities. (i.e. increase in sedges and rushes) Timing, duration, • Insufficient flooding Low to moderate- regime itself does not Minor- it is anticipated that there will not be a change Low frequency and magnitude to cue provide appropriate cues to stimulate from how species currently respond to the regime. The magnitude of flooding waterbird breeding waterbird breeding; however it will continue to permanent nature of the system will continue to provide (and drawdown) on • Increased exposure to provide good conditions for fledging and a drought refuge reducing the risks associated with the success of predators (particularly juvenile success. insufficient duration, nest abandonment etc. The main waterbird breeding species nesting in reeds, issue is the absence of major flooding to cue breeding, and fledging rushes etc of littoral zone) however breeding the site supports good breeding in its current condition. Flooding event • Waterbird breed in small Moderate - the regime will result in inundation Moderate- Although appropriate cues for waterbird Moderate provided in the numbers when triggered during low rainfall years, which does not follow breeding may not be triggered under the regime, the absence of regional/ by flooding/ rainfall the regional climatic situation. Annual topping wetland provides a refuge during dry years for breeding. climatic trigger up will result in only a small fluctuation in The drawdown (within the ranges specified in Section water level in winter/spring which may be an 8.3) will follow natural seasonal patterns, which may insufficient cue on its own to stimulate assist. breeding. Impact of changed • Caspian Tern Low- The regime will maintain sufficient open Minor- There is little evidence of Caspian Terns breeding Low regime on significant water to support fish, the primary food source at inland wetlands and it is therefore assumed that their wetland dependent of the Caspian Tern (Rogers and Ralph, 2010). presence at Middle Reedy Lake is primarily for feeding species (Rogers and Ralph, 2011). Feeding should not be negatively impacted under the proposed regime.
• Eastern Great Egret Low - Eastern Great Egrets prefer permanent Minor to moderate - the regime will maintain the Low waterbodies, but also frequent shallows of wetland as a permanent system whilst promoting deep permanent wetlands and semi- increased diversity at the littoral zone. However the permanent swamps. The proposed regime will regime will not promote reestablishment of trees which maintain the site as a permanent wetland, and are an important nesting and breeding component for will promote increased littoral zone vegetation Eastern Great Egret (especially flooded trees) (Rogers (Rogers and Ralph, 2011). Eastern Great Egret and Ralph, 2011). has not been recorded at Middle Reedy Lake since 2009 (see Section 5.3).
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Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
End Point Stressor Risk description Exposure Ecological effect Rating • Freckled Duck Low - Freckled Duck is almost entirely aquatic Minor to moderate- The proposed regime will maintain Low and prefer densely vegetated waters. The a permanent regime which is desirable for Freckled forage in the shallows and drawdown zones Duck. The fluctuating water level should promote and feed primarily on insects and plant increased food availability. The lack of aquatic material (Rogers and Ralph, 2011). The vegetation in the open water zone may attribute to the proposed regime should promote more lack of use in recent years. seasonality in water level fluctuations which may facilitate establishment of small drawdown zones. Freckled Duck has not been recorded in Middle Reedy Lake since 1999. • Musk Duck Low- Musk Ducks are almost entirely aquatic Minor to moderate- the regime aligns with the Low and prefer stable conditions with abundant requirements of Musk Duck. Absence of flooding may aquatic vegetation. They nest over deep water reduce breeding success (Rogers and Ralph, 2011). and dive up to 6m in search of aquatic invertebrates (Rogers and Ralph, 2011). The proposed regime will maintain conditions for the species. Musk Duck has not been recorded in Middle Reedy Lake since 2006. • Blue-billed Duck Low - Blue-billed Duck requires similar Minor to moderate- the regime aligns with the Low conditions to Musk Duck (as above) i.e. prefer requirements of Musk Duck. Absence of flooding may deep wetlands with stable water levels and reduce breeding success (Rogers and Ralph, 2011). The abundant aquatic vegetation. Blue-billed Duck lack of aquatic vegetation in the open water zone may has not been recorded at Middle Reedy Lake attribute to the lack of use in recent years (i.e. since 1990. duckweed). • Gull-billed Tern Low- the proposed regime is unlikely to impact Minor- the regime should not impact on the Low on Gull-billed Tern who utilise canegrass, reed requirements of the species. However lack of aquatic and rushes to feed. Gull-billed Tern has not vegetation may attribute to the lack of use in recent been recorded at Middle Reedy Lake since years. 2006. • Latham’s Snipe Low - Latham’s Snipe inhabits open freshwater Minor- Latham’s Snipe does not breed in Australia; Low wetlands with low, dense vegetation (DSE, therefore its presence at Middle Reedy Lake would 2012c). The regime will promote increased purely be for feeding. The regime should not impact on seasonality of this littoral zone. Latham’s Snipe the feeding requirements of the species. has not been recorded at Middle Reedy Lake since 2003.
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End Point Stressor Risk description Exposure Ecological effect Rating • Hardhead Low - Hardheads prefers wetlands with Minor – the regime should not impact on the Low abundant aquatic vegetation and deep water requirements of the species. for foraging. The regime aims to promote an increase in aquatic vegetation (Rogers and Ralph, 2011). Hardhead has not been recorded in Middle Reedy Lake since 2011. • Nankeen Night Heron Low - Nankeen Night Herons are nocturnal Minor to moderate – The regime should maintain Low feeders that utilise well vegetated littoral conditions suitable for Nankeen Night Heron however zones with tall emergent vegetation. They nest Crome (1988) (cited in Rogers and Ralph, 2011) in trees, shrubs and reed beds and feed on documented that breeding is triggered by flooding and aquatic animals, particularly fish, frogs and that there is an increase in success following a few insects (Rogers and Ralph, 2011). The proposed months of drying. should not impact on feeding, breeding and nesting opportunities. Nankeen Night Heron has not been recorded at Middle Reedy Lake since 1988. • Pied Cormorant Low - Pied Cormorants prefer stable water Minor - the regime should not impact on the current Low levels typical of permanent freshwater wetland conditions that support Pied Cormorants. systems and feed primarily on fish and crustaceans. The regime aligns well with these requirements (Rogers and Ralph, 2011). • Royal Spoonbill Low- Royal Spoonbills are known to utilise Minor to moderate- The regime will promote Low both permanent and ephemeral wetlands and appropriate conditions for Royal Spoonbill breeding and like semi-aquatic herbs or emergent feeding during wet phase. However Crome (1988) (cited vegetation. They forage in shallow water in Rogers and Ralph, 2011) found that there was an feeding on fish and insects and roost and nest increase in breeding success of Royal Spoonbills after a in trees, shrubs, reeds, rushes and lignum completely dried, which will not occur under the (Rogers and Ralph, 2011). The requirements of proposed regime. Royal Spoonbill align well with the proposed regime. • Whiskered Tern Low- the proposed regime will maintain Moderate- the regime will not negatively impact on Low Middle Reedy Lake as a permanent wetland Whiskered Tern compared to the current regime, with minor fluctuations in water level. This however the lack of an inter-flood dry period may inhibit should promote some regeneration of littoral breeding success. A complete dry promotes productivity vegetation which supports the prey of of Whiskered Terns prey (insects, frogs etc). However Whiskered Tern. Whiskered Tern has not been the drawdown phase may contribute to some prey recorded at Middle Reedy Lake since 2012. productivity increases.
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Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
End Point Stressor Risk description Exposure Ecological effect Rating • White-bellied Sea Eagle Low- The regime should not impact negatively Very minor - Habitat and feeding opportunities for Low on White-bellied Sea-Eagle and will maintain White-bellied Sea-Eagles will not be impacted by the good feeding opportunities. changed regime (DSE, 2003).
Turtles Reduced extent and • Lack of suitable habitat due Low- depth and extent of flooding will not be Minor- the wetland will continue to support appropriate Low depth of flooding to a change in vegetation reduced under the proposed regime. At all permanent conditions for turtles. composition times a minimum of 1.7m depth will be • Increased predation maintained. • Turtle death Frogs Reduced extent and • Lack of suitable habitat due Low- conditions will continue to support frogs Minor- conditions will broadly remain the same, and Low depth of flooding to change in vegetation and may provide more favourable conditions therefore are likely to continue to support the same frog habitat composition through seasonal fluctuations at the littoral species. • Increased predation zone. Native fish Reduced extent and • Lack of suitable habitat due Moderate-the regime will broadly continue to Moderate- The regime will not promote an increase in Moderate depth of flooding to change in vegetation maintain conditions as per the current regime. Tangled Lignum and other aquatic vegetation which is habitat composition likely to be providing shelter for the species in Middle • Fish death Reedy Lake. Furthermore the small fluctuations are • Increased predation unlikely to promote breeding associated with rising water levels. Impact of changed • Freshwater Catfish Low- The proposed regime will maintain at Minor- the regime will not result in a dramatic shift in Low regime on significant least 1 m of water at all times. Freshwater the current habitat and food sources available. species Catfish has not been recorded at Middle Reedy Lake since 1981.
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End Point Stressor Risk description Exposure Ecological effect Rating • Murray Hardyhead Moderate - Murray Hardyhead was recorded Moderate-severe- The impact of the current regime on Moderate- for the first time in Middle Reedy Lake in 2013. Murray Hardyhead is not understood. The conditions in high The regime will not result in a dramatic shift in the wetland do not correspond with those observed in habitat and food sources compared to the other wetlands that support the species (i.e. Middle current regime, however there is the potential Reedy Lake is fresh and therefore has more predators that the species has already declined, due to than saline environments. Ruppia the primary habitat for predation and in adequate conditions. Murray Hardyhead and is not recorded etc). There is the potential that this species entered the system during the 2010-11 floods and the low number of species recently recorded, may indicate that there was a large population that has declined. However, the species may have already persisted at the site, and the population may be a relic of its former distribution. Also MHH are an annual species, their continued existence therefore suggests suitable habitat is in existence for the completion of critical life stages. • Silver Perch Low- The proposed regime will maintain at Minor- Silver Perch should remain within the wetland Low least 1 m of water at all times. Silver Perch has under the proposed regime. not been recorded at Middle Reedy Lake since 2006 . • Unspecked Hardyhead Low- The proposed regime will continue to Minor – Unspecked Hardyhead should remain within the Low provide permanent conditions. Unspecked wetland under the proposed regime. Hardyhead has not been recorded at Middle Reedy Lake since 2006. • Golden Perch Low- The proposed regime will maintain at Minor -Golden Perch is stocked in at First Reedy Lake Low least 1 m of water at all times. which supplements the native population. The regime will maintain appropriate water depth (Rogers and Ralph, 2011). • Murray Cod Low- The proposed regime will maintain at Minor -Murray Cod is stocked in First Reedy Lake which Low least 1 m of water at all times. supplements the native population. The regime will maintain appropriate water depth. Non-native Conditions favour • Increased predation and Low - the regime will broadly continue to Moderate- severe - Impact of species such as Gambusia Low- fish non-native species competition for resources maintain conditions as per the current regime on the Murray Hardyhead population of Middle Reedy moderate with native species and therefore it is not expected that a change Lake is currently unknown. Common Carp have caused • Habitat damage (i.e. will allow non-natives to thrive. damage to the aquatic vegetation (particularly in the increased turbidity) deep water zone), and may continue to impact on turbidity reducing water clarity and reducing seedling establishment.
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End Point Stressor Risk description Exposure Ecological effect Rating Processes Connectivity Inappropriate • Inability for species to Unknown Dependent on Bypass infrastructure. Refer to KBLIP Landscape Scale Consideration Report (North Central infrastructure or move to more CMA, 2014). management favourable conditions • Lack of seed dispersal • Lack of flushing • Water quality issues Water quality Increased • Increase in primary Very low- the regime will result in a maximum Minor- the regime will follow a natural pattern of Very low temperature productivity drop of 30cm. This should not result in a winter/spring fill and a summer drawdown. The variability • Change in species change to the water temperature. maximum change in depth is considered minimal and it composition is anticipated that it will not result in a change to the • Possible impact on flora water temperature. diversity favouring temperature tolerant species High litter level • Algae blooms Low - Increased microbial activity will occur in Minor - it is unlikely that a large amount of organic Low creates high organic • Depleted dissolved oxygen the drawdown zones in response to matter will accumulate in the littoral zone. Any load depressing and reduced pH can cause seasonality. accumulation would be diluted when the wetland is re- dissolved oxygen death to aquatic biota filled to FSL each year. Soils Increased drying to • Reduced water quality Very low - slow recession and extent of the Very minor - the regime will not result in the drying of Very low previously inundates • Erosion and loss of top-soil littoral zone that will be impacted by the previous inundate soils (with the exception of the 30cm soils if no vegetation regime. littoral zone that is currently exposed under the establishment management regime). • Aesthetically displeasing • Acid sulphate soils (mobilised during re-fill)
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Kerang Lakes Bypass Investigation Project Technical Report – Middle Reedy Lake
End Point Stressor Risk description Exposure Ecological effect Rating Groundwater Drying phase resulted • Increased salinity during High- It is possible that groundwater intrusion Severe - Groundwater intrusion would significantly Very high in saline groundwater summer/autumn due to may occur at Middle Reedy Lake if the site was impact on the flora and fauna supported by the wetland. intrusion/ changes to saline groundwater dried (driven by regional climate) when water level salinity intrusion regional groundwater levels are high (URS, Note: this may benefit some species (i.e. Murray • Increased stratification of 2013). Middle Reedy Lake was rated the Hardyhead) who can tolerate high salinity levels. water second highest KLBIP wetland in terms of • Increased salinity salinity risk. impacting on aquatic flora and fauna • Potential infiltration of saline groundwater into the wetland • Death of salt intolerant species Establishment of Acid • Exposure of soils to oxygen High- Middle Reedy Lake is ranked the highest Severe- ASS has the potential; to severely impact on the Very high Sulfate Soils (ASS) creating ASS risk of acquiring ASS (URS, 2013), although flora and fauna of Middle Reedy Lake. • Released and mobilised additional sampling is required to better during inundation events understand this risk.
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KLBIP Technical Report – Middle Reedy Lake
9.3. Mitigation Assessment A number of risks have been identified as part of the risk assessment for the objective of reintroducing variability to the water level at the littoral zone of Middle Reedy Lake (refer to Section 8.3). Mitigation actions and further assessment for each moderate, high or very high risk are considered as part of the risk mitigation in Table 22.
• Mitigation actions: risk mitigation measures have been recommended for Middle Reedy Lake to reduce the risk in providing a modified watering regime.
• Further assessment: whether significant species are exposed or if the surrounding environment / wetland habitats would provide refuge for the environmental values exposed to the risk.
A new risk rating is provided in Table 22; however some risks require further assessment.
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Table 22: Modified risk assessment End Point Stressor Risk description Initial Risk Mitigation Actions / Further Modified Exposure Modified Ecological effect Modified Rating Assessment Rating Indicator Aspects of the Biological or physical effect of the Significance • Actions recommended to reduce Exposure of the endpoint to the Potential effect on the stressor on Significance water regime that stressor on the endpoint of the risk level of risk stressor the endpoint of the risk potential affect • Consideration of surrounding the endpoint environment and species significance Habitat (flora) Aquatic Long history of • Lack of recruitment due to Moderate • Mature surrounding individuals Low- increased seasonality in Moderate- if aquatic Low vegetation inundation no/low existing seed bank should offer seed source if water level fluctuations vegetation is unable to r- • Establishment of exotics/ conditions right should allow seeds to establish naturally there is the competitive species • Provide a water regime that establish in littoral zone. option of planting mature • Death or deterioration in encourages a diversity of plant individuals that may contribute health species to establish to the seed stock. • Monitor establishment of species as part of the adaptive management process • Aquatic revegetation to be implemented if establishment does not naturally occur Shrubs (i.e. Long history of • Lack of recruitment due to High- very • Monitor current community and Moderate to high- although Moderate to high- there is the Further Tangled inundation no/low existing seed bank high the establishment of the species long term permanent need to monitor the Tangled assessment Lignum) • Death or deterioration in as part of the adaptive inundation with minimal Lignum community of Middle is required health management process fluctuations is likely to have Reedy Lake to ensure the • Undertake appropriate resulted in a loss of seed health does not continue to environmental weed control bank, this will be mitigated by deteriorate under the proposed where relevant aquatic revegetation if regime. In the event that some • Consider altering the regime required. However death or loss is observed, further to encourages a diversity deterioration of currently experimentation with water of plant species to establish established Tangled Lignum level fluctuations may be clumps cannot be mitigated required (First Reedy Lake may unless watering regime is also act as a test case for this as modified to allow some seed described in Section 8.3). establishment.
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End Point Stressor Risk description Initial Risk Mitigation Actions / Further Modified Exposure Modified Ecological effect Modified Rating Assessment Rating Fauna communities Waterbird Flooding • Waterbirds breed in small Moderate • Ensure watering events align Low - Regional Climatic Moderate- Water regime Low breeding events numbers when triggered by regional climatic conditions conditions considered in should be managed in line with provided in flooding/rainfall including flooding events. wetting and drying regime. seasonal and were appropriate the absence Site in its current regime regional climatic conditions. of regional/ supports good waterbird climatic numbers so regional climatic triggers triggers may be less important than habitat at Middle Reedy Lake. Native fish Reduced • Lack of suitable habitat due Moderate • Continue to maintain Low- to moderate- there are Moderate- the regime is Low- extent and to change in vegetation appropriate depth of <1m a number of strategies to unlikely to result in a dramatic moderate depth of habitat composition • Attempt to manage for exotic help reduce the impact of the change to habitat available for flooding • Fish death species (see below) regime on native fish species. • Increased predation • Continue to monitor health and including exotic species abundance of native fish species management and translocation. • Murray Hardyhead Moderate - • Consider translocating additional Moderate- the regime will Moderate- the regime is Moderate high Murray Hardyhead individuals to not dramatically alter the unlikely to result in a dramatic Middle Reedy Lake to increase current regime, however the change to habitat available for abundance and add genetic species is outside its normal species such as Murray diversity conditions and therefore Hardyhead. Therefore it is likely • Continue to maintain there is a risk that the species that this species will continue appropriate depth of <1m will be lost without to remain vulnerable to • Attempt to manage for exotic intervention. predation. species (see below) • Continue to monitor health and abundance of native fish species Non-native Conditions • Increased predation and Low- • Manage exotic species i.e. Low- the regime does not Moderate- the regime will not Low species favour non- competition for resources for moderate Gambusia and Common Carp change significantly from the assist with eradicating non- native species natives that directly impact on native current operations and natives (as a complete drying • Habitat damage (i.e. species (through predation of therefore it is unlikely that phase would do). However increased turbidity, shoreline competition for resources) the population will increase there are potentially a number erosion) • Monitor exotic species dramatically (i.e. lack of of strategies to assist with abundance disturbance or variability reducing abundance. • Undertake control measures if which often allows non- required. natives to gain a competitive edge and thrive).
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End Point Stressor Risk description Initial Risk Mitigation Actions / Further Modified Exposure Modified Ecological effect Modified Rating Assessment Rating Process Ground- Drying phase • Increased salinity during Very High • Modify the water regime to Low - Surrounding Low- Groundwater intrusion Further water resulted in summer/autumn due to ensure that wetland level is groundwater level will be will be minimised as there will assessment saline saline groundwater intrusion above groundwater levels considered in setting wetland be no or little gradient for is required groundwater • Increased stratification of • Additional modelling is level. The regime will manage groundwater to enter wetland. intrusion/ water required to better understand the wetland inside the changes to • Increased salinity impacting how the water regime will current operational levels. water level on aquatic flora and fauna change. salinity • Potential infiltration of saline groundwater into the wetland • Death of salt intolerant species Establishment • Exposure of soils to oxygen Very High • Additional sampling is required N/A – additional sampling is N/A – additional sampling is Further of Acid Sulfate creating ASS to better understand the risk required before an required before an assessment assessment Soils (ASS) • Released and mobilised of ASS. assessment can be made can be made is required during inundation events
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9.4. Risk and mitigation summary As detailed in Table 22 there are a number of risks associated with the proposed watering regime that cannot be fully mitigated through management intervention. This includes impacts to Murray Hardyhead and Tangled Lignum. As little information is available for both of these values further investigations are required as detailed in Section 10. 10. Knowledge gaps A proposed wetland water regime has been derived for Middle Reedy Lake based on the sites ecological values; however risks have also been identified in reintroducing variability to the water level at the littoral zone of Middle Reedy Lake (permanent regime with fluctuations). The following recommendations are required to understand some of the risks identified:
• Development of an Environmental Watering Plan (EWP): The development of an Environmental Watering Plan (EWP) is recommended for Middle Reedy Lake prior to the implementation of any water savings initiatives that will alter the current water regime. This will enable scientists and managers to work through an approved process to establish an environmental watering regime to protect and maintain the wetland’s environmental integrity. • Groundwater: there are risks associated with altering the current permanent regime at Middle Reedy Lake which are largely related to the relationship between wetland levels and the level of the surrounding groundwater. A more detailed groundwater model may be required to better estimate the implications of an adaptive management approach. • Murray Hardyhead: further investigations are required to establish the size, range, distribution and health of the Murray Hardyhead population at Middle Reedy Lake and connected KLBIP wetlands. Further to this, investigation into what is supporting the species (habitat requirements) would be beneficial for future management. It is also worth considering Murray Hardyhead translocation to the wetland, to increase the genetic diversity and abundance of the species. • Tangled Lignum: further investigations are required to better understand the biology and hydrological requirements of the permanently inundated Tangled Lignum community of Middle Reedy Lake. It is believed that the health and extent of the community is deteriorating and it is likely that the carrying capacity for breeding waterbirds will also reduce if this continues. • Acid Sulphate Soils: a more detailed Acid Sulphate Soils analysis is required to better understand the risk from drying the wetland, field investigations have not been undertaken to date. • Landscape scale: Middle Reedy Lake has been assessed in isolation of the KLBIP, consideration of the wetland system and connectivity with the landscape is required.
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11. References Barker, J., Grigg, G., Tyler, M. (1995). A field Guide to Australian Frogs . Surrey Beatty and Sons, Chipping Norton. Bren, L. (1992). Tree invasion of an intermittent wetland in relation to changes in the flood frequency of the River Murray, Australia . Australian Journal of Ecology, Vol. 17, pp. 395-408. Biosis (2013). Kerang Lakes Fauna Assessment- Draft report. Prepared for the North Central Catchment Management Authority. Biosis Pty Ltd, Melbourne. Birdlife Australia (2013). BirdLife Australia database. Accessed 9 June 2013 from http://birdlife.org.au/. Brock M.A., Nielsen D.l., Shiel R.J., Green J.D. and Langley J.D. (2003). Drought and aquatic community resilience: the role of eggs and seeds in sediments of temporary wetlands . Freshwater Biology 48: 1207– 1218 cited in Roberts and Marston (2011). Clunie, P. (2010). Description of the ecological character of the Kerang Lakes Ramsar site . Department of Sustainability and Environment. Corrick, A.H., and Norman, F.I., (1980 ). Wetlands of Victoria I. Wetlands and waterbirds of the Snowy River and Gippsland Lakes catchment . Proceedings of the Royal Society of Victoria 91:1–15. Dalby-Ball, M., Roberts, J., Sainty, G. (2000). Plant Management in the Kerang Wetlands: a case study of Hird Swamp . Reported developed by Parks Victoria. DEPI (2013). Fish stocking report . Retrieved 5 July 2013, from Department of Environment and Primary Industries: http://www.dpi.vic.gov.au/fisheries/about-fisheries/fish-stocking-reporting . DEWHA (2008 ). National Framework and Guidance for Describing the Ecological Character of Australia’s Ramsar Wetlands. Module 2 of the National Guidelines for Ramsar Wetlands- Implementing the Ramsar Convention in Australia . Australian Government Department of Environment, Water, Heritage and the Arts, Canberra. DEWHA (2009). National guidance on notifying change in ecological character of Australian Ramsar Wetlands (Article 3.2). Module 3 of the National Guidelines for Ramsar Wetlands- Implementing the Ramsar Convention in Australia. Australian Government Department of Environment, Water, Heritage and the Arts, Canberra. DSE (2003). Flora and Fauna Guarantee Action Statement- Grey-crowned Babbler . Department of Sustainability and Environment. Melbourne. DSE (2004). Kerang Wetlands Ramsar Site: Strategic Management Plan . Department of Sustainability and Environment, Melbourne. DSE (2005a). Index of Wetland Condition: Conceptual framework and selection of measures . Victorian Government, Melbourne.
DSE (2005b). Advisory List of Rare or Threatened Plants in Victoria. Department of Sustainability and Environment, Victoria.
DSE (2006). Kerang Lakes Ecological Character Description . Compiled by Pam Clunie, Department of Sustainability and Environment, Bendigo.
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DSE (2010). Kerang Wetland Ramsar Site Ecological Character Description . Department of Sustainability and Environment, Melbourne. DSE (2012a). Water and salinity regime and depth preference for Victorian wetland Ecological Vegetation Classes. Prepared for the Department of Sustainability and Environment. Pathways Bushland and Environment Consultants, Greensborough, Victoria. DSE (2012b). A field guide to Victorian Wetland Ecological Vegetation Classes for the Index of Wetland Condition 2 nd Edition . Department of Sustainability and Environment, Melbourne. DSE (2012c). Flora and Fauna Guarantee- Scientific Advisory Committee Final Recommendation on a Nomination for Listing- Gallinago hardwickii (Latham’s Snipe ). Retrieved 18 July 2013, from Department of Environment and Primary Industries: http://www.dse.vic.gov.au/__data/assets/pdf_file/0006/158712/Lathams-Snipe-FRR.pdf
DSE (2013). Advisory List of Threatened Vertebrate Fauna in Victoria. Department of Sustainability and Environment, Victoria. Ecological Associates (2010). Gunbower Forest Hipwell Road channel ecological benefit and risk analysis- final report. Prepared for the North Central Catchment Management Authority. Ecological Associates Pty Ltd, Malvern, SA. Fluvial System (2012). Preliminary hydrological modelling for Kerang Lakes bypass investigation project . Prepared for Goulburn-Murray Water. Fluvial Systems, Stockton, NSW. Gawne, B., Scholz, O. (2006). Synthesis of a new conceptual model to facilitate management of ephemeral deflation basin lakes. Lakes and Reservoirs: Research and Management , Vol. 11, pp. 177-188. Hale, J., (2009). Northern Victoria Irrigation Renewal Project: Operation Impact Assessment on Wetlands of International Importance (Ramsar Wetlands). Report to Hydro Environmental, Jennifer Hale, Kinglake. Ho, S., Roberts, J., Cheers, G., Suitor, L. (2006). Development and application of an ecological monitoring and mapping program for targeted Kerang Lakes . Report prepared for the North Central Catchment Management Authority. Murray-Darling Freshwater Research Centre, Mildura. KBR (2007). Assessment Framework of changed water management regimes on the health of the Kerang Lakes . Prepared for the Department of Sustainability and Environment. Kellogg Brown and Root, St Kilda. KBR (2011). Kerang Wetlands Ramsar Site: Ecological Character Description . Draft reported prepared for the Department of Sustainability, Environment, Water, Population and Communities, Kellogg Brown and Root, St Kilda. Lugg, A., Heron, S., Fleming, G., O’Donnell, T. (1989). Report to Kerang Lakes Area Working Group- Report 1: Conservation values of the wetlands in the Kerang Lakes Area. Department of Conservation Forest and Lands and Kerang Lakes Assessment Group. Macumber, P. G. (2009). The hydrogeology, Hydrology and Management of Round Lake. Phillip Macumber Consulting Services, Donvale, Melbourne. Mitch, W. and Gosselink, J. (2000). Wetlands, Third Edition . John Wiley and Sons, New York. North Central CMA (2011). Kerang Lakes Water Savings Project Investigation – Literature Review. North Central Catchment Management Authority, Huntly.
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North Central CMA (2012). Alternative Water Regimes for Kerang Lakes Bypass Investigation Project – Phase 1. North Central Catchment Management Authority, Huntly. North Central CMA (2014). Kerang Lakes Bypass Investigation Project – Landscape Scale Considerations . Prepared for the Goulburn-Murray Water Connections Project, North Central Catchment Management Authority, Huntly, Victoria. O’Donnell, T (1990). Vegetation of the wetlands in the Kerang Lakes area. A report to Kerang Lakes Area Working Group (KLAG). Department of Conservation, Forest and Lands, Bendigo region. Rakali (2013). Ecological Vegetation Class Assessment for the Reedy Lake system, Little Lake Charm and Racecourse Lake surrounding areas in the Kerang Wetlands Ramsar Site . Report prepared for the North Central Catchment Management Authority, Huntly. Ramsar (2005). The Criteria for Identifying Wetlands of International Importance. The Ramsar Convention on Wetlands . Ramsar, Iran, 1971. Roberts, J. and Marston, F. (2011). Water Regime for Wetland and Floodplain Plants: A Source Book for the Murray-Darling Basin . National Water Commission, Canberra, ACT. Rogers, K. and Ralph, TL. (Eds) (2011). F loodplain Wetland Biota in the Murray-Darling Basin: Water and Habitat Requirements . CSIRO Publishing, Collingwood, Victoria. SKM (2006). Kerang to Little Murray Floodplain Management Plan- Assessment of Options . Report prepared for the North Central CMA, Huntly, Victoria. SKM (2010). Environmental water regime requirements of the Kerang Lakes . Reported prepared for Goulburn-Murray Water. Sinclair Knight Merz, Tatura. Stoessel, D. (2012). Status of Lake Kelly, Round Lake, and Woorinen North Lake Murray Hardyhead (Craterocephalus fluviatilis) populations, and assessment of potential translocation sites in north-central Victoria. Unpublished client report No 2012/77 . Prepared for the Department of Sustainability and Environment, Regional Services. Department of Sustainability and Environment, Heidelberg, Victoria. Tucker, P. Harper, M. Dominelli, S. van der Wielen, M.and Siebentritt, M. (2002). Your Wetland: Hydrology Guidelines. Department of Environmental Biology, University of Adelaide, Adelaide. URS (2013). Kerang Lakes Bypass Investigation Project: Hydrogeological Risk Assessment: Conceptual Model and Project Summary Report . Prepared for the Goulburn-Murray Water Connections Project. URS Australia, Tatura, Victoria. VEAC (2008). Identifying flood-dependent natural values on the Victorian floodplains of the River Murray and its tributaries . Prepared by the Victorian Environmental Assessment Council.
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Appendix A: Bathymetry Height Area Volume (mAHD) (ha) (ML) 71.77 0.00 0.00 71.80 0.00 0.00 71.85 0.00 0.00 71.90 0.01 0.00 71.95 0.01 0.01 72.00 0.04 0.02 72.05 0.06 0.04 72.10 0.09 0.08 72.15 0.11 0.13 72.20 0.14 0.20 72.25 0.17 0.27 72.30 0.20 0.37 72.35 0.24 0.48 72.40 0.27 0.61 72.45 0.31 0.75 72.50 0.35 0.92 72.55 0.38 1.10 72.60 0.42 1.30 72.65 0.46 1.52 72.70 0.50 1.76 72.75 0.54 2.02 72.80 0.59 2.30 72.85 1.01 2.68 72.90 1.99 3.40 72.95 5.09 4.96 73.00 15.28 9.66 73.05 30.06 20.88 73.10 48.12 40.04 73.15 66.41 68.82 73.20 79.79 105.56 73.25 91.30 148.35 73.30 99.78 196.29 73.35 107.08 247.97 73.40 112.06 302.85 73.45 115.82 359.84 73.50 119.09 418.59 73.55 121.88 478.84 73.60 124.50 540.44 73.65 126.95 603.31 73.70 129.11 667.34 73.75 131.12 732.40 73.80 133.09 798.45 73.85 135.07 865.49 73.90 137.06 933.52 73.95 139.08 1002.55 74.00 141.21 1072.62 74.05 143.68 1143.80 74.10 147.89 1216.66 74.15 152.29 1291.66 74.20 159.86 1369.53 74.25 169.31 1451.06 74.30 175.49 1537.30 74.35 178.79 1626.03 74.40 180.56 1715.89 74.45 181.72 1806.49 74.50 182.54 1897.56 74.55 183.31 1989.02 74.60 184.10 2080.87 74.65 184.84 2173.09 74.70 186.53 2265.87 74.75 188.73 2359.69 74.80 191.15 2454.66 74.85 193.39 2550.80 74.90 195.41 2648.01 74.95 197.03 2746.13 --- denotes cross section referred to in Figure 4 and Figure 6.
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Description of map
Watering regimes:
Minimum: Annual regime (permanent regime- allow season fluctuations between 74.88 (blue line) and 74.33m AHD (red line) (1.6m depth) to expose small portion of Tangled Lignum zone
Optimum/ maximum: Annual regime (permanent regime- allow season fluctuations between 74.88 (blue line) and 74.57m AHD (yellow/green line))
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Appendix B: 2013 EVC mapping
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Appendix C: Flora and fauna species list Source: Ho et al. 2006; SKM, 2010; Rakali, 2013; Biosis, 2013; DEPI, 2013; BirdLife Australia, 2013 Table C1: Flora and fauna recorded at Middle Reedy Lake Common Name Scientific Name Last record Source Fauna- Birds DEPI, 2013; Ho et al. 2006; BirdLife Australia, Australasian Darter Anhinga novaehollandiae 2012 2013 Australasian Grebe Tachybaptus novaehollandiae 2011 DEPI, 2013; BirdLife Australia, 2013 Australian Magpie Cracticus tibicen 2012 BirdLife Australia, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Australian Pelican Pelecanus conspicillatus 2009 2013 Australian Raven Corvus coronoides 2012 DEPI, 2013; BirdLife Australia, 2013 Australian Reed-Warbler Acrocephalus australis 2011 BirdLife Australia, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Australian Shelduck Tadorna tadornoides 2012 2013 Australian Spotted Crake Porzana fluminea 1990 DEPI, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Australian White Ibis Threskiornis molucca 2013 2013; Rakali, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Australian Wood Duck Chenonetta jubata 2012 2013 Black Kite Milvus migrans 2012 DEPI, 2013; BirdLife Australia, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Black Swan Cygnus atratus 2012 2013 Black-faced Cuckoo-shrike Coracina novaehollandiae 2011 BirdLife Australia, 2013 Black-shouldered Kite Elanus axillaris 2012 BirdLife Australia, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Black-tailed Native-hen Tribonyx ventralis 2011 2013 Black-winged Stilt Himantopus himantopus 2011 BirdLife Australia, 2013 Blue-billed Duck Oxyura australis 1990 DEPI, 2013 Blue-faced Honeyeater Entomyzon cyanotis 2001 BirdLife Australia, 2013 Brown Falcon Falco berigora 2012 DEPI, 2013; BirdLife Australia, 2013 Brown Goshawk Accipiter fasciatus 2012 BirdLife Australia, 2013 Caspian Tern Hydroprogne caspia 2013 BirdLife Australia, 2013; Rakali 2013 Chestnut Teal Anas castanea 2011 DEPI, 2013; BirdLife Australia, 2013 Cockatiel Nymphicus hollandicus 1999 BirdLife Australia, 2013 Common Starling+ Sturnus vulgaris 2011 BirdLife Australia, 2013 Crested Pigeon Ocyphaps lophotes 2012 DEPI, 2013; BirdLife Australia, 2013 Crimson Rosella Platycercus elegans 2006 BirdLife Australia, 2013 DEPI, 2013; Clunie, 2010; BirdLife Australia, Dusky Moorhen Gallinula tenebrosa 2012 2013 Dusky Woodswallow Artamus cyanopterus 2012 BirdLife Australia, 2013 DEPI, 2013; SKM, 2010; BirdLife Australia, Eastern Great Egret Ardea modesta 2009 2013 Eastern Rosella Platycercus eximius 2012 DEPI, 2013; BirdLife Australia, 2013 2012 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Eurasian Coot Fulica atra 2013 Fairy Martin Petrochelidon ariel 2011 BirdLife Australia, 2013 Freckled Duck Stictonetta naevosa 1999 DEPI, 2013; BirdLife Australia, 2013 Galah Eolophus roseicapillus 2012 DEPI, 2013; BirdLife Australia, 2013 Golden Whistler Pachycephala pectoralis 2007 BirdLife Australia, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Great Cormorant Phalacrocorax carbo 2012 2013 Grey Shrike-thrush Colluricincla harmonica 2012 DEPI, 2013; BirdLife Australia, 2013 Grey Teal Anas gracilis 2011 DEPI, 2013; BirdLife Australia, 2013 Grey-crowned Babbler Pomatostomus temporalis temporalis 2013 Rakali 2013
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Common Name Scientific Name Last record Source Gull-billed Tern Sterna nilotica 2006 SKM 2010; Ho et al. 2006 DEPI, 2013; Ho et al. 2006; BirdLife Hardhead Aythya australis 2011 Australia, 2013 Horsfield's Bronze-Cuckoo Chalcites basalis 2012 BirdLife Australia, 2013 House Sparrow Passer domesticus 2011 BirdLife Australia, 2013 Latham's Snipe Gallinago hardwickii 2003 BirdLife Australia, 2013 Laughing Kookaburra Dacelo novaeguineae 1998 BirdLife Australia, 2013 2011 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Little Black Cormarant Phalacrocorax sulcirostris 2013 Little Corella Cacatua sanguinea 1999 BirdLife Australia, 2013 Little Eagle Hieraaetus morphnoides 2012 BirdLife Australia, 2013 Little Grassbird Megalurus gramineus 2004 DEPI, 2013; BirdLife Australia, 2013 Little Pied Cormorant Microcarbo melanoleucos 2011 DEPI, 2013; BirdLife Australia, 2013 Little Raven Corvus mellori 2011 BirdLife Australia, 2013 Magpie-lark Grallina cyanoleuca 2012 DEPI, 2013; BirdLife Australia, 2013 Masked Lapwing Vanellus miles 2011 DEPI, 2013; BirdLife Australia, 2013 Musk Duck Biziura lobata 2006 DEPI, 2013; Ho et al. 2006 Musk Lorikeet Glossopsitta concinna 2007 BirdLife Australia, 2013 Nankeen Kestrel Falco cenchroides 2012 BirdLife Australia, 2013 Nankeen Night Heron Nycticorax caledonicus hillii 1988 DEPI, 2013 Noisy Miner Manorina melanocephala 2012 DEPI, 2013; BirdLife Australia, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Pacific Black Duck Anas superciliosa 2012 2013 Peregrine Falcon Falco peregrinus 2004 BirdLife Australia, 2013 Pied Butcherbird Cracticus nigrogularis 2010 BirdLife Australia, 2013 DEPI, 2013; BirdLife Australia, 2013; Rakali Pied Cormorant Phalacrocorax varius 2013 2013 Pink-eared Duck Malacorhynchus membranaceus 2011 BirdLife Australia, 2013 Plumed Whistling-Duck Dendrocygna eytoni 1985 DEPI, 2013 DEPI, 2013; Ho et al. 2006; BirdLife Australia, Purple Swamphen Porphyrio porphyrio 2012 2013 Red-capped Plover Charadrius ruficapillus 2011 BirdLife Australia, 2013 Red-kneed Dotterel Erythrogonys cinctus 2011 DEPI, 2013; BirdLife Australia, 2013 Red-necked Avocet Recurvirostra novaehollandiae 1990 DEPI, 2013 Red-rumped Parrot Psephotus haematonotus 2012 DEPI, 2013; BirdLife Australia, 2013 Ho et al. 2006; BirdLife Australia, 2013; Royal Spoonbill Platalea regia 2013 Biosis, 2013 Rufous Whistler Pachycephala rufiventris 2007 BirdLife Australia, 2013 Sacred Kingfisher Todiramphus sanctus 2011 BirdLife Australia, 2013 Silver Gull Chroicocephalus novaehollandiae 2011 DEPI, 2013; BirdLife Australia, 2013 Singing Honeyeater Lichenostomus virescens 2012 BirdLife Australia, 2013 Spotless Crake Porzana tabuensis 2013 Rakali 2013 Spotted Harrier Circus assimilis 2012 BirdLife Australia, 2013 Straw-necked Ibis Threskiornis spinicollis 2012 DEPI, 2013; Ho et al. 2006; BirdLife Australia, 2013 Striated Pardalote Pardalotus striatus 2009 BirdLife Australia, 2013 Superb Fairy-wren Malurus cyaneus 2011 DEPI, 2013; BirdLife Australia, 2013 Swamp Harrier Circus approximans 2012 DEPI, 2013; BirdLife Australia, 2013; Ho et al. 2006 Tree Martin Petrochelidon nigricans 2010 BirdLife Australia, 2013 Variegated Fairy-wren Malurus lamberti 2012 BirdLife Australia, 2013 Wedge-tailed Eagle Aquila audax 2012 BirdLife Australia, 2013 Welcome Swallow Hirundo neoxena 2012 DEPI, 2013; BirdLife Australia, 2013 Whiskered Tern Chlidonias hybridus 2012 DEPI, 2013; BirdLife Australia, 2013 Whistling Kite Haliastur sphenurus 2012 DEPI, 2013; BirdLife Australia, 2013
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Common Name Scientific Name Last record Source DEPI, 2013; BirdLife Australia, 2013; Rakali White-bellied Sea-Eagle Haliaeetus leucogaster 2013 2013 White-breasted Woodswallow Artamus leucorynchus 2012 BirdLife Australia, 2013 White-browed Babbler Pomatostomus superciliosus 2007 BirdLife Australia, 2013 White-faced Heron Egretta novaehollandiae 2011 DEPI, 2013; BirdLife Australia, 2013 White-fronted Chat Epthianura albifrons 2011 BirdLife Australia, 2013 White-necked Heron Ardea pacifica 2009 BirdLife Australia, 2013 White-plumed Honeyeater Lichenostomus penicillatus 2012 DEPI, 2013; BirdLife Australia, 2013 Willie Wagtail Rhipidura leucophrys 2012 BirdLife Australia, 2013 DEPI, 2013; Clunie, 2010; BirdLife Australia, Yellow-billed Spoonbill Platalea flavipes 2009 2013 Yellow-throated Miner Manorina flavigula 2006 DEPI, 2013 Zebra Finch Taeniopygia guttata 1991 DEPI, 2013 Fauna - Fish Australian Smelt Retropinna semoni 2013 Ho et al. 2006 and Biosis, 2013 Bony Bream Nematalosa erebi 2013 DEPI, 2013; Ho et al. 2006; Biosis, 2013 Carp Gudgeon Hypseleotris spp. 2013 Ho et al. 2006 and Biosis, 2013 Common Carp+ Cyprinus carpio 2013 DEPI, 2013; Ho et al. 2006 and Biosis, 2013 Flathead Gudgeon Philypnodon grandiceps 2013 SKM 2010 and Bisosis, 2013 Craterocephalus stercusmuscarum Unspecked Hardyhead fulvus 2006 SKM 2010; Ho et al. 2006; Biosis, 2013 Freshwater Catfish Tandanus tandanus 1981 DEPI, 2013; SKM 2010 Gambusia+ Gambusia holbrooki 2013 Ho et al. 2006 and Biosis, 2013 DEPI, 2013; SKM 2010 and Ho et al. 2006; Golden Perch Macquaria ambigua 2013 Biosis, 2013 Goldfish+ Carassius auratus 2013 DEPI, 2013; Ho et al. 2006; Biosis, 2013 Murray Cod Maccullochella peelii 2013 DEPI, 2013; SKM, 2010; Bisosis, 2013 Murray Hardyhead Craterocephalus fluviatilis 2013 Biosis, 2013 Oriental Weatherloach+ Misgurnus anguillicaudatus 2013 Biosis, 2013 Redfin Perch+ Perca fluviatilis 2013 DEPI, 2013; Ho et al. 2006; Biosis, 2013 Silver Perch Bidyanus bidyanus 2006 DEPI, 2013; Ho et al. 2006 Tench+ Tinca tinca 1981 DEPI, 2013 Fauna- Other Barking Marsh Frog Limnodynastes fletcheri 2013 Biosis, 2013 Boulenger's skink Morethia boulengeri 2013 Rakali, 2013 Common Froglet Crinia signifera 1991 DEPI, 2013 Eastern Long-necked Turtle Chelodina longicollis 2013 Rakali, 2013; Biosis, 2013 European Rabbit+ Oryctolagus cuniculus 2013 DEPI, 2013; Rakali, 2013 Marbled gecko Christinus marmoratus 2013 Biosis, 2013 Murray River Turtle Emydura macquarii 2013 Rakali, 2013; Biosis, 2013 Red Fox+ Vulpes vulpes 2013 Rakali, 2013 Southern Bullfrog (ssp. unknown) Limnodynastes dumerilii 1991 DEPI, 2013 Spotted Marsh Frog Limnodynastes tasmaniensis 2013 Biosis, 2013 Swamp Wallaby Wallabia bicolor 2013 Rakali, 2013 Tiger Snake Notechis scutatus 2013 Rakali, 2013 Tree Skink Egernia striolata 2013 Rakali, 2013; Biosis, 2013 Water Rat Hydromys chrysogaster 2013 Rakali, 2013 Macroinverbrates Atyidae - 2013 Ho et al. 2006; Biosis, 2013 Baetidae - 2013 Ho et al. 2006; Biosis, 2013 Caenidae - 2013 Biosis, 2013 Ceratopogonidae - 2013 Biosis, 2013 Chironominae - 2013 Ho et al. 2006; Biosis, 2013 Coenagrionidae - 2013 Ho et al. 2006; Biosis, 2013
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Common Name Scientific Name Last record Source Corixidae - 2013 Ho et al. 2006; Biosis, 2013 Dytiscidae - 2013 Ho et al. 2006; Biosis, 2013 Ecnomidae - 2013 Biosis, 2013 Hydrophilidae - 2013 Ho et al. 2006; Biosis, 2013 Hydroptilidae - 2006 Ho et al. 2006 Leptoceridae - 2013 Biosis, 2013 Mesoveliidae - 2006 Ho et al. 2006 Naucoridae - 2013 Ho et al. 2006; Biosis, 2013 Notonectidae - 2013 Ho et al. 2006; Biosis, 2013 Oligochaeta - 2013 Biosis, 2013 Orthocladiinae - 2013 Biosis, 2013 Palaemonidae - 2013 Ho et al. 2006; Biosis, 2013 Parastacidae - 2013 Biosis, 2013 Physidae - 2013 Ho et al. 2006; Biosis, 2013 +denotes exotic species Flora- Native Australian Salt-grass Distichlis distichophylla 2013 Raklai, 2013 Australian Saltmarsh-grass Puccinellia stricta var. stricta 2013 Raklai, 2013 Osteocarpum acropterum var. Babbagia 2013 Raklai, 2013 deminutum Berry Saltbush Atriplex semibaccata 2013 Raklai, 2013 Billabong Rush Juncus usitatus 2013 Raklai, 2013 Black Box Eucalyptus largiflorens 2013 Raklai, 2013 Tecticornia pergranulata subsp. Blackseed Glasswort 2013 Raklai, 2013 pergranulata Box Mistletoe Amyema miquelii 2013 Raklai, 2013 Senecio cunninghamii var. Branching Groundsel 2013 Raklai, 2013 cunninghamii Bristly Wallaby-grass Rytidosperma setaceum 2013 Raklai, 2013 Broad-leaf Cumbungi Typha orientalis 2013 Raklai, 2013 Brown Beetle-grass Leptochloa fusca subsp. fusca 2009 SKM 2010 Ludwigia peploides subsp. Clove-strip 2013 DEPI, 2013; Raklai, 2013 montevidensis Coarse Water-milfoil Myriophyllum caput-medusae 1960 DEPI, 2013 Common Blown-grass Lachnagrostis filiformis s.s. 2013 Raklai, 2013 Common Boobialla*# Myoporum insulare 2013 Raklai, 2013 Common Duckweed Lemna disperma 2013 Raklai, 2013 Common Reed Phragmites australis 2013 Raklai, 2013 Common Spike-sedge Eleocharis acuta 2013 DEPI, 2013; Raklai, 2013 Common Swamp Wallaby-grass Amphibromus nervosus 2013 Raklai, 2013 Common Wallaby-grass Rytidosperma caespitosum 2013 Raklai, 2013 Cotton Fireweed Senecio quadridentatus 2013 DEPI, 2013; Raklai, 2013 Cumbungi Typha domingensis 2006 Ho et al. 2006 Early Spring-grass* Eriochloa pseudoacrotricha 2013 Raklai, 2013 Eumong* Acacia stenophylla 2013 Raklai, 2013 Flat-top Saltbush Atriplex lindleyi subsp. lindleyi 2013 Raklai, 2013 Giant Rush Juncus ingens 2013 Raklai, 2013 Gold Rush Juncus flavidus 1960 DEPI, 2013 Grey Roly-poly Sclerolaena muricata var. villosa 2013 Raklai, 2013 Hedge Saltbush* Rhagodia spinescens 2013 DEPI, 2013; Raklai, 2013 Jersey Cudweed Helichrysum luteoalbum 2013 Raklai, 2013 Mallee Love-grass Eragrostis dielsii 2013 Raklai, 2013 Melaleuca spp. ?? 2001 SKM 2001 Moonah# Melaleuca lanceolata 2013 Raklai, 2013
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Common Name Scientific Name Last record Source Moss Sunray Hyalosperma demissum 1982 DEPI, 2013 Native Couch Cynodon dactylon var. pulchellus 2013 Raklai, 2013 Native Sow-thistle Sonchus hydrophilus 2013 Raklai, 2013 Nitre Goosefoot Chenopodium nitrariaceum 2013 DEPI, 2013; Raklai, 2013 Nitre-bush Nitraria billardierei 2013 Raklai, 2013 Nodding Saltbush Einadia nutans subsp. nutans 2013 Raklai, 2013 Old-man Saltbush Atriplex nummularia 2013 Raklai, 2013 Pacific Azolla Azolla filiculoides 2013 Raklai, 2013 Pale Knotweed Persicaria lapathifolia 2013 DEPI, 2013; Raklai, 2013 Pervian Primrose Ludwigia peruviana 2001 SKM 2001 Poong'ort Carex tereticaulis 2013 Raklai, 2013 Prickly Saltwort Salsola tragus 2013 Raklai, 2013 Prickly Saltwort Salsola tragus subsp. tragus 2013 Raklai, 2013 Rat-tail Couch Sporobolus mitchellii 2013 Raklai, 2013 River Club Rush Schoenoplectus validus 2006 Ho et al. 2006 River Club-sedge Schoenoplectus tabernaemontani 2013 Raklai, 2013 River Red-gum Eucalyptus camaldulensis 2013 SKM 2001, Rakali 2013 Robust Water-milfoil Myriophyllum papillosum 2013 Raklai, 2013 Rosinweed Cressa australis 2013 Raklai, 2013 Ruby Saltbush Enchylaena tomentosa var. tomentosa 2013 Raklai, 2013 Rudy Ground Fern Hypolepis rugosula 2001 DEPI, 2013; SKM 2001 Melaleuca halmaturorum subsp. Salt Paperbark# 2013 Raklai, 2013 halmaturorum Salt Sea-spurrey Spergularia sp. 3 2013 Raklai, 2013 Short Water-starwort Callitriche brachycarpa 2013 Raklai, 2013 Short-leaf Bluebush Maireana brevifolia 2013 Raklai, 2013 Slender Knotweed Persicaria decipiens 2013 DEPI, 2013; Raklai, 2013 Slender-fruit Saltbush Atriplex leptocarpa 2013 Raklai, 2013 Small Loosestrife Lythrum hyssopifolia 2013 Raklai, 2013 Small Spike-sedge Eleocharis pusilla 2013 Raklai, 2013 Southern Cane-grass Eragrostis infecunda 2013 Raklai, 2013 Spiny Flat-sedge Cyperus gymnocaulos 2013 Raklai, 2013 Spiny Lignum Duma horrida subsp. horrida 2013 DEPI, 2013; SKM 2001; Rakali 2013 Sprawling Saltbush* Atriplex suberecta 2013 Raklai, 2013 Eremophila divaricata subsp. Spreading Emu-bush# 2013 Raklai, 2013 divaricata Star Fruit Damasonium minus 2013 Raklai, 2013 Swamp Buttercup Ranunculus undosus 1977 DEPI, 2013 Swamp Crassula Crassula helmsii 2013 Raklai, 2013 Tall Fireweed Senecio runcinifolius 2013 Raklai, 2013 Tall Sedge Carex appressa 2013 Raklai, 2013 Tangled Lignum Duma florulenta 2013 SKM 2001, Rakali 2013 Tassel Sedge Carex fascicularis 2013 Raklai, 2013 Tiny Duckweed Wolffia australiana 2013 Raklai, 2013 Twin-leaf Bedstraw Asperula gemella 2013 SKM 2010, Raklai 2013 Water Milfoil Myriophyllum papillosum 2006 Ho et al. 2006 Water Pepper Persicaria hydropiper 2013 Raklai, 2013 Water Primrose Ludwigia peploides 2001 SKM 2001 Waterwort Elatine gratioloides 2013 Raklai, 2013 Windmill Grass Chloris truncata 2013 Raklai, 2013 *Taxon which is both indigenous and naturalised but has extended beyond its known or suspected geographical distribution #Planted Flora- Exotic African Box-thorn Lycium ferocissimum 2013 Raklai, 2013
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Common Name Scientific Name Last record Source Annual Beard-grass Polypogon monspeliensis 2013 Raklai, 2013 Aster-weed Aster subulatus 2013 Raklai, 2013 Basket Willow Salix X rubens 2013 Raklai, 2013 Black Nightshade Solanum nigrum s.l. 2013 Raklai, 2013 Celery Apium graveolens 1977 DEPI, 2013 Celery Buttercup Ranunculus sceleratus subsp. sceleratus 2013 Raklai, 2013 Clustered Dock Rumex conglomeratus 2013 Raklai, 2013 Common Ice-plant Mesembryanthemum crystallinum 2013 Raklai, 2013 Common Sow-thistle Sonchus oleraceus 2013 Raklai, 2013 Couch Cynodon dactylon var. dactylon 2013 Raklai, 2013 Curled Dock Rumex crispus 2013 Raklai, 2013 Desert Ash Fraxinus angustifolia 2013 Raklai, 2013 Drain Flat-sedge Cyperus eragrostis 2013 Raklai, 2013 Fog-fruit Phyla canescens 2013 Raklai, 2013 Great Brome Bromus diandrus 2013 Raklai, 2013 Grey Sallow Salix cinerea 2013 Raklai, 2013 Horehound Marrubium vulgare 2013 Raklai, 2013 Jointed Rush Juncus articulatus subsp. articulatus 2013 DEPI, 2013; Rakali, 2013 Lesser Quaking-grass Briza minor 2013 Raklai, 2013 Mullumbimby Couch Cyperus brevifolius 2013 Raklai, 2013 Ox-tongue Helminthotheca echioides 2013 Raklai, 2013 Pimpernel Anagallis arvensis 2013 Raklai, 2013 Prickly Lettuce Lactuca serriola 2013 Raklai, 2013 Rough Sow-thistle Sonchus asper s.s. 2013 Raklai, 2013 Sea Barley-grass Hordeum marinum 2013 Raklai, 2013 False Daisy Eclipta prostrata 2013 Raklai, 2013 Spear Thistle Cirsium vulgare 2013 Raklai, 2013 Spiny Rush Juncus acutus subsp. acutus 2013 Raklai, 2013 Stinkwort Dittrichia graveolens 2013 Raklai, 2013 Sweet Melilot Melilotus indicus 1977 DEPI, 2013 Tall Wheat-grass Lophopyrum ponticum 2013 Raklai, 2013 Water Buttons Cotula coronopifolia 2013 Raklai, 2013 Water Couch Paspalum distichum 2013 Raklai, 2013 Weeping Willow Salix babylonica s.l. 2013 Raklai, 2013 Willow-leaf Lettuce Lactuca saligna 2013 Raklai, 2013 Yorkshire Fog Holcus lanatus 2013 Raklai, 2013
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Appendix D: Water requirements of ecological values Table D1: Ecological values supported at Middle Reedy Lake Example (*denotes threatened) General requirements Values Listed species General species Feeding Habitat Breeding Waterbird feeding guilds Caspian Tern: stimulated by flood and season (Sept- Feb) Eastern Great Egret and Pied Cormorant: generally stimulated by flood Caspian Tern, and season (Sept- Australasian Eastern Great May) for ~ 12 Darter, Pelican, Egret, Pied Prefer permanent Prefer permanent months Great Cormorant, Cormorant, water however water body. Whiskered Tern: Little Black Whiskered shoreline can recede. Generally trees, stimulated by Fish eating Cormorant, Little Tern, White- Fish , crustaceans, shrubs (i.e. lignum) floods and season waterbirds Pied Cormorant, bellied Sea reptiles, small and dense to (Oct- Jan) for 2 White-faced Eagle, Gull- mammals, aquatic moderate reeds. months Heron, Sacred billed Tern, insects Gull-billed Tern: Kingfisher, White- Nankeen stimulated by flood, necked Heron Night Heron rainfall and season (Sept- Jan) for 4 months Nankeen Night Heron: breed throughout year pending availability of food, breed in colonies with egrets and cormorants. Australian White Generally roost in Ibis, Black-winged Prefer shallow with Royal Spoonbill: trees in wetlands and Stilt, Red-capped short vegetation. Diet stimulated by flood generally nest over Plover, Red-kneed consist primarily of and season (Oct- Waders (large Royal thick emergent Dotterel, Red- insects, spiders, May) for more than and small) Spoonbill vegetation i.e. rushes, necked Advocet, molluscs, 5 months. reeds or lignum. Straw-necked Ibis, crustaceans, small Will abandon nest Yellow-billed mammals and reptiles upon fast recession Spoonbill Australian Grebe, Freckled Duck: Australia, stimulated by flood Shelduck, (June-Dec) for 6 Australian months Spotted Crake, Generally Hardhead: Ducks Freckled Australian Wood opportunistic but stimulated by flood including: Duck, Duck, Dusky some prefer deep and and season (Aug- Dabbling Generally algae, Hardhead, Moorhen, permanent water. Dec) for 5-8 months ducks/ grazing grasses, seeds, herbs, Musk Duck, Eurasian Coot, Trees, reeds, lignum, Musk Duck: waterfowl/ aquatic plants, Blue-billed Grey Teal, Pacific shrubs, grasses, stimulated by flood shoreline insects, shoots, Duck, Black Duck, rushes (dense). Nest and season (June- foragers/ macros Latham’s Purple in densely vegetated Dec) for 6 -8 deep water Snipe Swamphen, Black areas near open months foragers Swan, Black-tailed water Blue-billed Duck: Native-hen, Stimulated by flood Chestnut Teal, and season (Sept- Masked Lapwing, Feb) for 5-6 months Pin-eared Duck, Latham’s Snipe:
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Example (*denotes threatened) General requirements Values Listed species General species Feeding Habitat Breeding Plumed Whistling Do not breed in Duck, Spotless Australia Crake, White- fronted Chat
Grey Crowned Babbler : Insects and Grey-crowned Grey-crowned larvae and sometimes Trees with nest made Babbler: July to Feb Babbler, seeds of grasses, twigs and Other N/A Spotted Spotted Harrier: stick sometimes in Spotted Harrier: Harrier quail and pipits, mice, tree hollows July to October rats, rabbits and lizards Fish guilds Murray Hardyhead: stimulated by water temperature and Small aquatic Slow-flowing or still day length (Sept- Unspecked Australian Smelt, invertebrates, water associated with Feb) Wetland Hardyhead, Bony Bream, Carp zooplankton, detritus, aquatic vegetation Generally opportunists Murray Gudgeon, microorganisms, and sometimes opportunists: Hardyhead Flathead Gudgeon crustaceans, aquatic woody debris temperature and in vegetation (Bony Bream- turbid) some cases rising flows cues spawning (broadly Sept-April) Slow flowing riverine Murray Cod, Water temperature Main channel crustaceans, insects, with woody debris Freshwater N/A cues spawning specialists fish and frogs (Catfish with Catfish (Sept-Dec) mud/sand/gravel) Slow flowing turbid Rise of water level Aquatic insects, water with littoral veg Flood Golden Perch, and temperature N/A crustaceans, aquatic and woody debris spawners Silver Perch cues spawning plant material (also deep for Golden (broadly Oct-Jan) Perch) Reptiles In spring and Aquatic vegetation, Murray River Eastern Long- Requires permanent summer lay eggs in Turtles macro inverts and Turtle necked Turtle water burrow close to carrion water Generally Mix, some prefer Common Froglet, somewhere open water other Southern Bullfrog between spring and prefer abundant (spp. Unknown) , Insects, aquatic autumn after heavy Frogs N/A emergent veg Spotted Marsh vegetation rains. Lay eggs in (Barking Marsh frog), Frog, Barking slow moving/ still others are generalists Marsh Frog water or terrestrial (Spotted Marsh frog) habitat Example (*denotes threatened) Requirement General EVC Ecological service Listed species characteristic/ Frequency Duration species Dominate flora EVCs Narrow-leaf Filters water, adds Cumbungi, Broad- biological activity, Tall Marsh Branching leaf Cumbungi, Annual or near annual habitat, frogs and (EVC 821) Groundsel Tiny Duckweed, flooding (8-10 years 1 to 8 months turtles, refuge, Tall Fireweed, in every 10). nesting for River Club-sedge, waterbirds
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Example (*denotes threatened) General requirements Values Listed species General species Feeding Habitat Breeding Common Reed
Swamp Crassula, Clove-strip, Aquatic Annual or near annual Robust Water- 1-8 months before Herbland (EVC N/A inundation (8-10 milfoil, Slender drying 653) years in every 10) Knotweed, Tall Fireweed EVC: Inundate less EVC: >1 month to > 1 Tangled Lignum, Lignum than 3 years in every year before drying Cane Grass, Nitre Shrubland N/A 10 years (see below for Goosefoot, (EVC 808) (see below for Tangled Lignum) couches etc Tangled Lignum) Tangled Lignum, EVC: Inundate 3-7 Clove-strip, EVC: >1 month to > 1 Lignum years in every 10 Australian year before drying Swamp (EVC N/A years Saltmarsh-grass, (see below for 104) (see below for Broad-leaf Tangled Lignum) Tangled Lignum) Cumbungi EVC: Inundate 3-7 Lignum EVC: >1 month to > 1 years in every 10 Swampy Tangled Lignum, year before drying N/A years Woodland Black Box, acacias (see below for (see below for (EVC 823) Tangled Lignum) Tangled Lignum) **The Tangled Lignum population ** Tangled 1 in 3 years (can in Middle Reedy is considered an Lignum (i.e. endure less but anomaly and permanent Generally 3-7 months part of EVC lignum unlikely to be inundation is generally detrimental 808, 104 and strong enough to to health (Roberts and Marston, Key waterbird 823) support nesting) 2011). habitat (i.e. fallen Annual or near annual trees, hollows, inundation (e.g. every 1-8 months, then roosting and shade) Species such as Saltmarsh- 8 to 10 years in every dries or for and provides seeds Australian grass Swamp N/A 10 years). Can exist in intermittent >1 for recruitment Saltmarsh grass (EVC A113) intermittent scenario month to > 1 year and other grasses (inundate 3-7 years in before drying every 10 years) Semi-arid Chenopod Saltbushes, Nite- N/A No flooding required Woodland bush etc (EVC 98) Slender-fruit Riverine Saltbush, Nitre Flat-top Chenopod Goosefoot, Inundate less than 3 >1 month to > 1 year Saltbush, Woodland Windmill Grass, years in every 10 before drying Spiny Lignum (EVC 103) Tangled Lignum, Black Box etc Twin-leaf Flood every 3 to 7 Bedstraw, years for 3 to 6 Intermittent Red Gum Natural preferable Flat-top months for Swampy Saltbush, woodlands Woodland Short Water- Flood every 2 to 4 (EVC 813) Spring-summer starwort, Black Box years for 2 to 4 flooding Native Couch, months
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Example (*denotes threatened) General requirements Values Listed species General species Feeding Habitat Breeding Spiny Lignum, Branching Other: Tangled Groundsel, Lignum, Sedges, Inundate less than 3 Spreading Saltbushes, >1 month to > 1 year in 10 years Emu-bush 1, couch, rushes, Salt Cotton Fireweed Paperbark 1 Supports long term fish populations, Open water benthic macros, fish with small Almost never dries eating birds and areas similar Species such as (holds water >8 years possibly turtles, to Submerged N/A water celery may Constant inundation in every 10) but levels prevents algae Aquatic be present may fluctuate dominance. Some Herbland (EVC between years dead timber 918) provides roosting habitat Source: Biosis, 2013; Rakali, 2013; DSE, 2012a; DSE, 2012b; Rogers and Ralph, 2011; Roberts and Marston, 2011; Barker et al. 1995. 1Planted significant species.
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Appendix E: Water regime summaries Table E1: Recommended watering for Middle Reedy Lake Middle Reedy Lake: recommended watering regime Long term regime • Fill to FSL 74.88m AHD in late winter/spring and allow to recede over summer (maintaining minimum depth of 74.57m AHD) • Water level should fluctuate by up to 30cm • Top-up as required to ensure level does not drop below 74.57m AHD (1.7m depth).
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