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Impacts to Water Quality in the Murray-Darling Basin arising from Climate Change LITERATURE REVIEW Draft B 10 February 2011 Impacts to Water Quality in the MurrayDarling Basin arising from Climate Change LITERATURE REVIEW Draft A 10 February 2011 Sinclair Knight Merz ABN 37 001 024 095 590 Orrong Road, Armadale 3143 PO Box 2500 Malvern VIC 3144 Australia Tel: +61 3 9248 3100 Fax: +61 3 9248 3400 Web: www.skmconsulting.com LIMITATION: This report has been prepared on behalf of and for the exclusive use of Sinclair Knight Merz Pty Ltd’s Client, and is subject to and issued in connection with the provisions of the agreement between Sinclair Knight Merz and its Client. Sinclair Knight Merz accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this report by any third party. The SKM logo trade mark is a registered trade mark of Sinclair Knight Merz Pty Ltd. Literature Review Published by Murray-Darling Basin Authority Postal Address GPO Box 1801, Canberra ACT 2601 Office location Level 4, 51 Allara Street, Canberra City Australian Capital Territory Telephone (02) 6279 0100 international + 61 2 6279 0100 Facsimile (02) 6248 8053 international + 61 2 6248 8053 E-Mail [email protected] Internet http://www.mdba.gov.au For further information contact the Murray-Darling Basin Authority office on (02) 6279 0100 This report may be cited as: Sinclair Knight Merz, 2010, Impacts to water quality in the MurrayDarling Basin arising from Climate change, Murray-Darling Basin Authority, Canberra. MDBA Publication No. 127/11 ISBN 978-1-921783-86-9 © Copyright Murray-Darling Basin Authority (MDBA), on behalf of the Commonwealth of Australia 2011. This work is copyright. With the exception of photographs, any logo or emblem, and any trademarks, the work may be stored, retrieved and reproduced in whole or in part, provided that it is not sold or used in any way for commercial benefit, and that the source and author of any material used is acknowledged. Apart from any use permitted under the Copyright Act 1968 or above, no part of this work may be reproduced by any process without prior written permission from the Commonwealth. Requests and inquiries concerning reproduction and rights should be addressed to the MDBA Copyright Administration, Murray-Darling Basin Authority, GPO Box 1801, Canberra ACT 2601 or by contacting + 61 2 6279 0100. The views, opinions and conclusions expressed by the authors in this publication are not necessarily those of the MDBA or the Commonwealth. To the extent permitted by law, the MDBA and the Commonwealth excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this report (in part or in whole) and any information or material contained within it. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE i Literature Review Contents Glossary of Terms 6 1. Purpose 1 1.1. 1.2. 1 2 2. 3. 4. Project Objective This report Climate Change and the Murray-Darling Basin 3 2.1. 2.2. 3 4 Observed climate changes Future climate change predictions Impacts of Climate Change on Surface Water Quality 6 3.1. 3.2. Introduction Surface water quality drivers 6 6 3.2.1. 3.2.2. Land use/Vegetation Hydrology 7 8 3.3. Climate change impacts 3.3.1. 3.3.2. 3.3.3. Direct impacts Indirect impacts Water quality – climate change relationships 13 14 15 3.4. Climate change impacts in the Murray-Darling Basin 15 9 3.4.1.1. Dry Extreme 3.4.1.2. Wet Extreme 3.4.1.3. Interactions of wet and dry sequences 17 18 19 3.5. 20 Conclusions Impacts of Climate Change on Groundwater Quality 21 4.1. 4.2. Introduction Groundwater quality drivers 21 21 4.2.1. 4.2.2. 4.2.3. Watertable Elevation Influence of water balance on water quality Other drivers of groundwater quality 21 22 23 4.3. Climate Change impacts on groundwater quality 23 4.3.1. Direct impacts on water balance 4.3.1.1. Precipitation 4.3.1.2. Recharge via Irrigation Returns 4.3.1.3. River Leakage 4.3.1.4. Evapotranspiration 4.3.1.5. Discharge to Streams 4.3.1.6. Groundwater pumping 4.3.2. Indirect impacts on water balance 23 23 24 25 25 25 25 26 SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE ii Literature Review 4.3.2.1. Agricultural water management 4.4. 5. 26 Potential impacts to groundwater quality in Murray-Darling Basin 26 4.4.1. Current groundwater quality issues 4.4.1.1. Sodic Soils 4.4.1.2. Trace Metals 4.4.1.3. Herbicides 4.4.1.4. Microbiota 4.4.1.5. Dryland Salinty 4.4.2. Potential climate change impacts 4.4.2.1. Dryland Salinity 4.4.2.2. Pollutants 4.4.2.3. Surface Water Quality 26 27 27 27 27 28 28 28 29 29 4.5. 29 Conclusions and Recommendations Water Quality in the Murray-Darling Basin 5.1. 5.2. General summary Region by Region 5.2.1. Barwon-Darling 5.2.1.1. Overview 5.2.1.2. Values 5.2.1.3. Threats 5.2.1.4. Water quality summary 5.2.2. Border Rivers 5.2.2.1. Overview 5.2.2.2. Values 5.2.2.3. Threats 5.2.2.4. Water quality summary 5.2.3. Campaspe 5.2.3.1. Overview 5.2.3.2. Values 5.2.3.3. Threats 5.2.3.4. Water quality summary 5.2.4. Condamine-Balonne 5.2.4.1. Overview 5.2.4.2. Values 5.2.4.3. Threats 5.2.4.4. Water quality summary 5.2.5. Goulburn-Broken 5.2.5.1. Overview 5.2.5.2. Values 5.2.5.3. Threats 5.2.5.4. Water quality summary 31 Error! Bookmark not defined. 39 39 39 40 41 41 43 43 44 44 45 46 46 46 47 47 48 48 49 49 50 50 50 51 52 52 SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE iii Literature Review 5.2.6. Gwydir 5.2.6.1. Overview 5.2.6.2. Values 5.2.6.3. Threats 5.2.6.4. Water quality summary 5.2.7. Lachlan 5.2.7.1. Overview 5.2.7.2. Values 5.2.7.3. Threats 5.2.7.4. Water quality summary 5.2.8. Loddon 5.2.8.1. Overview 5.2.8.2. Values 5.2.8.3. Threats 5.2.8.4. Water quality summary 5.2.9. Macquarie-Castlereagh 5.2.9.1. Overview 5.2.9.2. Values 5.2.9.3. Threats 5.2.9.4. Water quality summary 5.2.10. Moonie 5.2.10.1. Overview 5.2.10.2. Values 5.2.10.3. Threats 5.2.10.4. Water quality summary 5.2.11. River Murray 5.2.11.1. Overview 5.2.11.2. Values 5.2.11.3. Threats 5.2.11.4. Water quality summary 5.2.12. Murrumbidgee 5.2.12.1. Overview 5.2.12.2. Values 5.2.12.3. Threats 5.2.12.4. Water quality summary 5.2.13. Namoi 5.2.13.1. Overview 5.2.13.2. Values 5.2.13.3. Threats 5.2.13.4. Water quality summary 5.2.14. Ovens 5.2.14.1. Overview 53 53 54 55 55 56 56 56 57 57 58 58 59 60 60 61 61 61 62 63 64 64 64 65 65 67 67 67 68 69 70 70 70 71 71 73 73 73 74 74 75 75 SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE iv Literature Review 6. 5.2.14.2. Values 5.2.14.3. Threats 5.2.14.4. Water quality summary 5.2.15. Paroo 5.2.15.1. Overview 5.2.15.2. Values 5.2.15.3. Threats 5.2.15.4. Water quality summary 5.2.16. Warrego 5.2.16.1. Overview 5.2.16.2. Values 5.2.16.3. Threats 5.2.16.4. Water quality summary 5.2.17. Wimmera-Avoca 5.2.17.1. Overview 5.2.17.2. Values 5.2.17.3. Threats 5.2.17.4. Water quality summary 75 76 76 78 78 78 79 79 81 81 81 82 82 83 83 83 84 84 5.3. Assets dependent on good water quality 85 5.3.1. 5.3.2. Environmental Drinking water 85 86 References 88 SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE v Literature Review Glossary of Terms DO Dissolved Oxygen EC Electrical Conductivity GCM Global Climate Model MDB Murray-Darling Basin MDBA Murray-Darling Basin Authority TP Total Phosphorus TN Total Nitrogen SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE vi Literature Review Document history and status Revision Date issued Reviewed by Approved by Date approved Revision type R01 21/04/10 S.Treadwell/N. Schofield B. Atkinson 22/04/10 Technical Review R01 22/04/10 T Church B. Atkinson 23/04/10 PD Review Distribution of copies Revision Copy no Quantity Issued to R01 07/05/2010 1xword Mathew Maliel, Alice Shields (MDBA) Printed: 10 February 2011 Last saved: 10 February 2011 11:48 AM File name: I:\VWES\Projects\VW04982\Deliverables\Reports\Literature Review\R01_bla_literature.docx Author: Dr Bonnie Atkinson Project manager: Dr Bonnie Atkinson Name of organisation: Murray-Darling Basin Authority Name of project: Impacts to Water Quality in the Murray-Darling Basin arising from Climate Change Name of document: Literature Review Document version: Draft A Project number: VW04982 SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE vii Literature Review 1. Purpose The Murray-Darling Basin (MDB) drains one-seventh of the Australian land mass and is the most significant agricultural area in Australia. Its water resources are highly utilised. Water is extracted to supply irrigated agriculture and drinking water to major towns and cities (most notably Adelaide). In addition, the MDB contains unique and diverse natural aquatic ecosystems, including rivers and internationally recognised wetlands. These ecosystems support 46 native fish species (Lintermans, 2007), and abundant birdlife, frogs, macroinvertebrates, mammals and plant life. The rivers and water bodies also have high recreational and cultural significance. All these beneficial uses of the water resources in the Murray Darling Basin are strongly dependent on good water quality. Climate change is likely to impact on the future quality of the MDB’s water resources, primarily through changes to the primary drivers of surface water quality - river hydrology and land use. Climate change may influence both river hydrology and land use through changed rainfall amounts and patterns, as well as rising temperatures (Jones et al., 2002). This is likely to affect surface water quality through higher water temperatures, altered flow regimes and water quality impacts associated with extreme events, including floods, bushfires and droughts (Bates et al., 2008). These changes will exacerbate the stress on rivers in the MDB that are already under pressure from high water use, salinity and declining water quality. Climate change impacts are also likely to affect groundwater resources through changes to the groundwater levels in key aquifers which will result in changes to groundwater-surface water interactions and their salt dynamics. Climate change risks to the basin’s water quality and quantity are complex and spatially varied. The Murray-Darling Basin Authority (MDBA) is striving to better understand the cumulative impacts of risks, the interaction between risks and the effectiveness of actions to mitigate risk. This project will help to inform the Risk Assessment Program within the MDBA and forms one of the three synthesis reports of Phase 2 of the overarching project ‘Implications of Climate Change for Natural Resource Management in the Murray-Darling Basin’. The findings of these synthesis reports will be developed into a framework for managing risks to the Basin’s water resources into the future. 1.1. Project Objective The objective of this study is to assess the risks to the water quality values in the Murray-Darling Basin under four climate scenarios: a. ‘Wet extreme’ (wet extreme scenario and associated modelled rainfall and runoff (CSIRO, 2008l)) SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 1 Literature Review b. ‘Return to normal’ (continuation of long-term averages 1895-2006 for rainfall and runoff) c. ‘Median 2030’ (median global warming scenario and associated modelled rainfall and runoff (CSIRO, 2008l) d. ‘Dry extreme’ (actual climate experienced during 1997-2006, including 15% less rainfall and 50% less runoff) The scope of the project includes both the northern and southern parts of the Murray-Darling Basin and will address: 1) Water quality trajectories in main-stem rivers in each of the MDB regions based on ‘end-ofvalley’ sites; 2) Water quality trajectories for 1-2 examples of iconic wetlands, drinking water reservoirs, irrigation infrastructure and groundwater aquifers; and 3) General water quality impacts from ‘extreme events’ (e.g. bushfires, hot weather, extended drought, flooding). 1.2. This report This report contains a literature review of the potential impacts to water quality arising from climate change. The key drivers of water quality in rivers and reservoirs are explored, followed by a synthesis of how climate change is anticipated to directly and indirectly affect water quality. The potential changes to water quality in the MDB with climate change are discussed and some casestudies presented. This report also provides a general summary of water quality issues in the basin, and a regional summary of the water quality dependent values, their threats and general trends. The conceptual understanding and regional knowledge documented in this report provides the necessary background information to feed into the risk assessment phase of this project. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 2 Literature Review 2. Climate Change and the Murray-Darling Basin Climate change is likely to have the greatest future impact on water resources in the MDB {CSIRO, 2008 #4}. It is predicted to cause rising temperatures, change the amount and distribution of rainfall, and increase the frequency and severity of extreme weather-related events (e.g. cyclones, prolonged droughts, major floods) across the MDB. This has implications for both water availability and land use, which are the two key drivers of water quality in rivers, wetlands, reservoirs and water supply systems. 2.1. Observed climate changes Australia is experiencing rapid climate change. There has been an increase in mean surface air temperatures and the frequency of heat-waves. The rainfall amounts and patterns have also changed. The northwest of the MDB has seen an increase in rainfall, while much of southeast MDB has experienced a decline (BOM, 2010). Since 1960, the mean temperature in Australia has increased by about 0.7 °C (Figure 2-1). The long term trend in temperature is clear, but there is still substantial year to year variability. The northern section of the MDB has experienced larger temperatures increases than the southern corner. Warming has occurred in all seasons, however, the strongest warming has occurred in spring (about 0.9 °C) and the weakest in summer (about 0.4 °C) (CSIRO, 2010). In addition, the number of hot days has increased each decade over the past 50 years, with 2000 to 2009 the warmest decade on record (CSIRO, 2010). Figure 2-1 Trend in mean temperature 1960-2009 (°C/decade) Source: Bureau of Meteorology 2010 SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 3 Literature Review There is a clear east-west rainfall and runoff gradient across the MDB, with most of the runoff generated in upland catchments in the south-east. The geographic distribution of rainfall has changed significantly over the past 50 years (Figure 2-2)(CSIRO, 2010). Rainfall has decreased markedly across the MDB, particularly in the southern basin from 1997-2006 due to the ‘Big-Dry’ drought, which may be linked to climate change. 2.2. Figure 2-2 Trend in annual rainfall 1960-2009 (mm per decade) Source: Bureau of Meteorology 2010 Future climate change predictions There is considerable uncertainty in the climate change predictions for the future, particularly when they are translated to the local-scale for regions within the MDB. A more detailed synthesis of climate change and the MDB can be found in CSIRO (2008l) and SKM (2009a). Of note, there are significant differences in the future rainfall projections between the 15 Global Climate Models (GCMs). Therefore, in order to assess the risks to water quantity and quantity in the MDB from climate change, it is appropriate to consider a range of future climate scenarios, which are outlined in Table 2-1. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 4 Literature Review Table 2-1 Future climate change scenarios to be considered in this study Future Climate Change Scenarios Description Historical Climate Wet Extreme 2030 Median 2030 Dry Extreme 2030 ‘Most favourable 2030’ scenario (continuation of long-term averages 1895-2006 for rainfall and runoff) The baseline for comparison with other scenarios. The actual 1895 to 2006 climate as represented in the river models used for developing current water sharing plans (CSIRO, 2008l). Wet-extreme 2030 climate in CSIRO (2008l) A range of possible future climates have been predicted using 15 GCMs, some predicting increases in rainfall, others a decrease. This scenario represents the ‘wet-extreme’ scenario and includes increases in rainfall and runoff by up to 11% across the MDB. It endeavours to capture the uncertainty in the range of future scenarios. ‘Median 2030’ scenario (medium global warming scenario and associated modelled rainfall and runoff) (CSIRO 2008) The median of likely climate changes by 2030 would be an 11 % reduction in average surface water availability across the MDB. This includes a 9 % reduction in average surface water availability in the north, and a 13 % reduction in the south-east where the majority of runoff is generated (CSIRO, 2008l). Dry extreme 2030 climate CSIRO (2008l) ‘Least favourable 2030’ scenario (actual climate experienced during 1997-2006, including 15% less rainfall and 50% less runoff) SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 5 Literature Review 3. Impacts of Climate Change on Surface Water Quality 3.1. Introduction This chapter considers the impacts to surface water quality arising from climate change. The key drivers of water quality in rivers and reservoirs are explored, followed by a synthesis of how climate change may directly and indirectly affect water quality. The current surface water quality issues in the MDB and potential changes to water quality with climate change are discussed and case-studies presented. 3.2. Surface water quality drivers The primary drivers of surface water quality are surrounding land use and catchment hydrology (Figure 3-1). These two drivers dictate the contaminant loads and in-stream concentrations and to a lesser extent the in-situ biogeochemical processes that occur. Thus, land use, catchment hydrology and in-situ biogeochemical processes are important determinants of in-stream water quality . Figure 3-1 Hydrological and land use effects on water quality (After SOE, 2009) SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 6 Literature Review 3.2.1. Land use/Vegetation One of the most important drivers of surface water quality is land use (Quinn et al., 1997; Baker, 2003). It is clear from the literature that water quality is directly attributable to the following characteristics of the catchment: Percentage of native vegetation and riparian zone cleared and/or replaced with other species, (Bunn et al., 1999; Rutherford et al., 2004); Intensity of agriculture and nature of agricultural practices including animal stocking rates (Sauer et al., 1999; Young and Huryn, 1999; Byers et al., 2005); and Density of human population, urbanisation and effluent disposal practices (Brabec et al., 2002; Walsh et al., 2005). Contaminants derived from these catchment influences can enter waterways and wetlands by point or non-point pathways. Point sources are typically from a specific location (usually a pipe or drain) and include sewage treatment plant, industrial, agricultural and urban discharges. Sewage treatment plant wastewater discharges and septic tank leakages are common sources of nutrients in waterways. The volume of point source inputs to waterways is typically proportional to the level of urbanisation in the catchment (Walsh, 2000). Non-point sources are not as easily identifiable. These sources of contaminants include runoff from farms, roads or lawns and erosion within the catchment. Nutrients and suspended solids are common in non-point runoff from farms and agricultural land, from use of fertilisers and stock access to waterways. Soil erosion can also be related directly to land use, and in particular, the amount of land-clearing (Prosser et al., 2003; Wallbrink, 2004). The major forms of soil erosion are gully, rill and stream bank erosion. All forms are caused by poor ground cover, drought, intense rainfall and/or unstable soils. Erosion is a major source of sediment, nutrients, and pesticides in surface water from catchments dominated by agricultural land (Prosser et al., 2003). Influence from non-point sources increase markedly during periods of heavy rainfall and increased runoff. Water quality is responsive to changes in vegetation and land-use. For instance, if cropping in one area ceases there will be lower pesticide levels from reduced spraying, less turbidity from disturbed soils, fewer nutrients from fertiliser additions and fewer irrigation demands, outfalls, and drainage requirements. Similarly, a reduction in the stocking rate of dairy cattle can reduce nutrients and soil erosion (Sauer et al., 1999). The type and severity of contamination from both point and non-point pathways are therefore linked directly to human activity. The following water quality parameters are typically affected: Physical - pH, temperature, total suspended solids and turbidity); SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 7 Literature Review Chemical - electrical conductivity, nutrients (nitrogen, phosphorus), dissolved oxygen, organic carbon, pesticides and biochemical oxygen demand; and Microbiological - Bacteria (faecal coliforms, E.Coli, Algae). 3.2.2. Hydrology Catchment hydrology has a complex relationship with water quality. However, it remains one of the key water quality drivers. The nature of the relationship depends strongly on the individual catchment and associated river system. Water quality is directly attributable to the following characteristics of the catchment and river hydrology: Source of water (i.e. groundwater, surface runoff, snow melt; irrigation transfers, flow releases from dams, stormwater, point sources); Flow impoundments (i.e. weirs, dams, diversions); and Flow regime (i.e. frequency and timing of freshening flows, high flows, low flows and ceaseto-flow events, river connectivity) (Poff et al., 1997; Richter et al., 1997). Good water quality typically is supported by a variable flow regime whereby each flow component fulfils particular functions to restore or maintain water quality. For instance, summer freshening flows can mix the water column and re-oxygenate refuge pools and control salinity levels, and bank-full flows can flush excessive accumulations of organic matter from the stream channel to prevent blackwater events. River regulation has disturbed the natural hydrology of most of the rivers in the MDB, which has had flow-on effects for water quality. Extreme weather events, such as drought and floods, also adversely affect water quality. Water quality generally declines during drought conditions (Caruso, 2001; Caruso, 2002). The slow flowing/still conditions during prolonged low flows and cease to flow events (in remnant pools) provide favourable conditions for algal blooms. Salinity levels can increase in some areas when saline groundwater constitutes a higher proportion of base flows. Water temperatures also rise during summer low flows, with stratification and concomitant decline in dissolved oxygen levels, which are critical for aquatic life (Caruso, 2001). There is also the potential in some areas for the aeration of potential acid sulphate soils (McCarthy et al., 2006). Contaminants from point sources, such as sewage treatment plants, can also be a higher proportion of the river flow, and can therefore degrade water quality. In contrast, large floods can initiate erosion and runoff in the catchment, transporting suspended solids, nutrients and other contaminants into the waterways (Prosser et al., 2001). This can be of particular importance when landscapes have been denuded of vegetation, for example from SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 8 Literature Review bushfires or severe droughts in the catchment, when large sediment and organic matter loads can enter waterways and cause significant declines in water quality. As a general principle, flowing water in rivers is in better condition than stationary water. Stationary water bodies can thermally stratify, which increases the likelihood of algal blooms, anoxic bottom water, the concentrations of metals, odour and taste problems. Flow releases from the cool bottom waters of stratified water bodies such as dams can also alter the water temperature of the river downstream for hundreds of kilometres, which may interfere with life-cycles for fish and invertebrates (Gehrke et al., 2003). 3.3. Climate change impacts Climate change can have a range of impacts on various environmental drivers that directly and indirectly affect water quality (Figure 3-2; Figure 3-3; Figure 3-4). While global warming is predicted to increase air temperatures, the effect on precipitation and hence runoff is variable (Poff et al., 1996). In some areas precipitation is expected to decrease and in other areas it will increase, or remain relatively stable. In most arid, semi-arid and temperate regions of Australia, a reduction in rainfall is most likely accompanied by an increase in the intensity of individual rainfall events (Pittock, 2003; Dunlop and Brown, 2008). Although a reduction in rainfall intensity has been noted during the recent drought {Verdon-Kidd, 2009 #60}. Together, elevated temperatures and decreased rainfall result in decreased runoff and an increase in the frequency and duration of low flow periods (Poff et al., 1996). While predictions for rainfall and runoff and highly uncertain, some models forecast declines of up to 50% in runoff for some parts of the Basin by 2050, compared to a historical baseline (1895-2006). In this context, increasing air temperatures will both directly and indirectly affect water quality while changes in precipitation and runoff will indirectly affect water quality. On this basis, we can look to the literature on drought and low flows to gain insights into the potential direct and indirect impacts of climate change on water quality. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 9 Literature Review Climate Change Increased Air Temperature Increased water temperature Vegetation Change Changes in nutrient leaching rates Changes in quality and quantity of organic matter inputs Increased microbial activity in soils Eutrophication Changes to ecosystem function N, P DOC, DO Decreased oxygen carrying capacity Increased rates of biological and chemical reactions Nutrient leaching to surface water Increased anoxia Increased nutrient and carbon cycling N, P DO Blackwater events Increased water use Earlier thermal stratification of pools and reservoirs Decreased volume for dilution of chemical through evaporation Reduced mixing Deoxygenation of hypolimnion Increased salinity Increased concentrations of nutrients and toxicants Algal blooms DO, N, P, Toxicants EC N, P, Toxicants Figure 3-2 Conceptual model for climate-change induced increased air temperature on water quality Table 3-1 Table of references for conceptual model (TO BE COMPLETED) Artificial flow regime Reservoir releases Prolonged low flows Cold/warm water pollution DO, Temp Temp Vegetation Change Increased water temperature Increased water use Species distribution changes, causing changes in nutrient leaching rates {Esselmont, 2007 #63;Lovett, 1999 #62} Decreased oxygen carrying capacity Prolonged low flows caused by an artificial flow regime Changes in the quality and quantity of organic matter inputs {Esselmont, 2007 #63} Increased rates of biological and chemical reactions Cold water pollution from reservoir releases {Astles, 2003 #7;Boys, 2009 #8} Increased soil processing rates may cause increased leaching of nutrients in the soil to surface water {Murdoch, 2000 #61}. Earlier thermal stratification of pools and reservoirs Decreased volume for dilution of chemicals through evaporation SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 10 Literature Review Climate Change Less rainfall in some areas, with more frequent and intense events Reduced runoff Increased bushfire frequency and intensity Low groundwater levels Increased water use/flow regulation Less allochthonous organic matter entrained in stream Prolonged Low flows/Cease-to-flow events Less surface water to dilute pointsource inputs Erosion and massive organic matter loads Lower base flows Arficial flow regime Reservoir releases Change to ecosystem function Diurnal extremes in temperature and dissolved oxygen Less dilution of contaminants Contaminant laden runoff during first intense rainfall postbushfire High surface water/groundwater contribution Blackwater events; Acid Sulfate Soils Cold/warm water pollution DOC, DO Temp, DO N, P, Toxicants N, P, TSS, OC, DO, EC EC DO, Temp, pH Temp Figure 3-3 Conceptual model for climate-change induced less rainfall on water quality SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 11 Literature Review Climate Change More rainfall in some areas, with more frequent and intense events Increased runoff Increased flooding frequency and intensity High groundwater levels Irrigation Allocations increase Increase in nutrient and TSS loads to reservoirs Diffuse source runoff from agricultural and urban areas Overflow of sewage, stormwater and other (i.e. tailing dam) infrastruture) Erosion Higher base flows Reservoir releases Eutrophication Higher contaminant loads Episodic increases in contaminant loads Catchment and river bank erosion Saline groundwater intrusion Cold/warm water pollution Algal blooms N, P, TSS, Pesticides N, P, E.coli, TSS, BOD N, P, TSS, OC, DO, EC EC Temp Figure 3-4 Conceptual model for climate-change induced increased rainfall on water quality SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 12 Literature Review 3.3.1. Direct impacts River and reservoir surface water temperatures will increase proportionally to increasing air temperatures, directly resulting in a variety of impacts including: In water storages, for irrigation or drinking water, increased temperature will result in the earlier onset of stratification and the delayed mixing of the water column (Poff et al., 2002). Consequently the problems associated with stratified water bodies will become more intense and prolonged. Problems relating to algal blooms, anoxic water, dissolved metals (iron and manganese), foul odour and taste, and downstream thermal pollution, are all related to stratified reservoir waters. Even in the absence of changed nutrient inflows, reservoirs may become more eutrophic due to increased rates of nutrient release from sediments. Feedback loops may also establish whereby reduced stream inflows result in a reduction in turbidity and DOC inputs which in-turn increase water clarity and light penetration, further increasing temperature and creating or enhancing conditions conducive to algal blooms. Increased temperature can increase rates of ecosystem functioning (primary productivity and community respiration), higher CO 2 levels may also contribute to increased algal growth rates (Hargrave et al., 2009). Increased temperatures also reduce the amount of oxygen than can be dissolved in water. Sufficient dissolved oxygen (DO) in the water column is critical for the survival of fish and macroinvertebrates, hence any reduction in DO has the potential to impact on a range of aquatic biota. Furthermore, DO is also important in a range of geochemical reactions and biological processes. A reduction in DO can result in the release of nutrients and heavy metals stored in sediment. This can result in eutrophication and increased algal growth, and also impact on the quality of water for consumptive uses in particular taste and odour. The life cycle of thermally sensitive fish and macroinvertebrates species may also be impacted and some may become locally extinct if temperature increases are above their maximum tolerance limits. Increased temperatures may also advantage some exotic pests, such as carp, and enable them to colonise new habitats, while the distribution of cold-water species such as trout may be restricted; and Increased local evaporation rates will also impact water quality through the concentration of pollutants including salt, metals, pesticides and nutrients in the water column. The hydrology of the MDB is largely modified, particularly due to river regulation including water storages and irrigation supply networks across the basin. Higher water temperatures and reduced stream flows are likely to cause contaminants to accumulate and water quality may become unacceptable to local users. Sediment, nutrients, dissolved organic carbon, pathogens, pesticides and salt levels may all increase and dissolved oxygen levels may decline with negative effects on ecosystems, human health, water system reliability and treatment costs. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 13 Literature Review 3.3.2. Indirect impacts Climate change may indirectly affect water quality through its primary drivers, land use and catchment hydrology. The water quality issues that may manifest, or increase in frequency, in rivers and wetlands due to climate change may include: High nutrient, organic matter and sediment loads from erosion following extreme rainfall events or extreme bushfire events, both of which are projected to increase with climate change. Increases in salinity due to less rainfall and runoff increasing the relative proportion of groundwater in rivers, which is compounded with increased water evaporation with higher water temperatures; Increased acidity from acid sulphate soils known to occur in the Murray Region due to changed flow regime and wetting and drying cycles; Changed climatic conditions are also likely to produce conditions that favour aquatic weeds and algal blooms, such as lower flows and cease-to-flow events; A reduction in runoff can lead to a longitudinal fragmentation of the river channel that prevents the normal transport of nutrients and organic carbon downstream (Bond et al., 2008). An accumulation of organic carbon combined with high temperatures and low DO can increase the frequency of black‐water events resulting in significant impacts on aquatic biota, including fish kills. Impacts on stormwater quality/quantity, affected by the increase in the frequency and intensity of extreme rainfall events; and Impacts on water and wastewater infrastructure, due to extreme precipitation causing damage to sewers and sewer overflows, which may increase sewer exfiltration into rivers. Climate change may also affect future vegetation and land-use patterns within the MDB. This may have both benefits and impacts on surface water and groundwater quality. Land use in the MDB is predominantly agriculture. Agricultural runoff increases nutrient, contaminant and suspended sediment loads in rivers through application of fertilisers, dairy effluents, use of pesticides and erosion of soils. As a result, the surface water resources have been compromised by algal blooms, rising salinity, sedimentation and pesticide contamination. Projected limitations on water availability under climate change mean that traditional farming practices are no longer feasible in some areas of the MDB. Therefore, the agricultural industry will continue to move towards sustainable farming and water conservative practices, which will provide environmental benefits. However, there may also be an increase in forestry in the region with follow on effects for the water balance in affected regions2. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 14 Literature Review 3.3.3. Water quality – climate change relationships Water quality trajectories and associated impacts from climate change can be understood by identifying how each parameter is affected by climate. Table 3-2 summarises the drivers and consequences for each water quality parameter of interest. Table 3-2 Drivers and consequences of changes to each water quality parameter Parameter Driver (s) Consequence (s) Dissolved oxygen Temperature Land use Stream flow Fish kills Water treatment issues Release of contaminants Nutrients Land use Floods Algal blooms Aquatic weeds Turbidity Land use Floods Water treatment issues Unsuitable for recreation Salinity Water balance Stream flow Unsuitable for irrigation Unsuitable for drinking Water Temperature Air Temperature Stream flow Thermal stratification Increased rates of ecosystem processes Thermal intolerance of fauna pH Stream flow – wetting and drying cycles of wetlands Land use – mining Unsuitable for recreation Unsuitable for drinking Unsuitable for irrigation Biochemical Oxygen Demand Land-use Stream flow Fish kills Water treatment issues Release of contaminants 3.4. Climate change impacts in the Murray-Darling Basin Climate change is expected to have highly variable localised impacts to water quality across the MDB. These impacts will be diverse, reflecting the diverse nature of the weather patterns of the basin. Overall, the southern basin is expected to become drier, whereas the northern basin may either get wetter or drier (Table 3-3). The wet extreme 2030 scenario is predicted to produce a 50% increase in water availability in the northern basin, but in the southern basin the water availability will not change significantly from historical conditions. The median and dry extreme 2030 scenarios all predict a decline in water availability. The southern basin may experience a 50% decrease under the dry extreme 2030 scenario (Table 3-3). Less water availability equates to less water in rivers and reservoir, and also less water allocations to support agricultural activities. The resultant changes in hydrology and land use are likely to SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 15 Literature Review affect water quality. These dry and wet scenarios, and the resultant effects on water quality, are considered below. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 16 Literature Review Table 3-3 Percentage changes in water availability in each region of the MDB under the 2030 climate change predictions (After CSIRO, 2008l) Location in MDB 2030 Climate Change Scenarios Historical (1895- 2006) Wet Median Dry NW 445 41% -3% -16% Warrego N-NW 420 47% -6% -30% Condamine-Balonne N-NE 1363 19% -8% -26% Moonie NE 98 24% -11% -29% Border Rivers NE 1208 18% -10% -26% Gwydir NE 782 34% -10% -29% Namoi NE 965 38% -5% -30% E 1567 26% -7% -25% N-Central 41* 49% -2% -22% Central 1139 6% -11% -30% S-Central 4270 13% -9% -28% Murray SE-SW 5211* 3% -11% -36% Ovens SE 1776 1% -13% -45% Goulburn-Broken SE 3233 -3% -14% -45% S 275 -4% -16% -46% Loddon-Avoca SW 285 -5% -18% -49% Wimmera SW 219 -5% -21% -53% -18% -52% Region Paroo Macquarie-Castlereagh Barwon-Darling Lachlan Murrumbidgee Campaspe Eastern Mount Lofty SW 120 -3% Ranges *only the fraction of the water availability generated in the catchment is shown. 3.4.1.1. Dry Extreme The ‘Dry’ climate change scenario is likely to affect surface water quality primarily by reducing surface water flows and increasing water temperatures. In the northern basin, the ephemeral Warrego, Paroo and Moonie Rivers may not have any flow during dry years. Analysis of historical water quality conditions in some ‘representative’ rivers in the MDB has shown that general water quality declines in ‘dry years’ (defined as the 10th percentile in river flows corresponding to the water quality record) (see Appendix A). There has been observed increases in water temperature in the Wimmera River (southern part of Basin) and a decline in dissolved oxygen levels. In the Darling River, dry conditions have led to an increase in algal blooms and a rise in pH. However, the relationships between some water quality parameters and ‘dry conditions’ varies across the basin. For instance, nutrient levels declined in the Darling River, but increased in the SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 17 Literature Review Wimmera River during dry years. This is likely to be a result of the ratio of point (continuous) vs. non-point (more likely during rainfall) sources of nutrients within the respective catchments. Similarly, salinity increased in the Darling River, but declined in the Wimmera River during dry years. This is related to the response of groundwater levels to the drought and to extractions. Typically however, salinity levels increase during dry conditions. Some water quality parameters improve during ‘dry conditions’. An example is turbidity, which is typically related to runoff and erosion generated during heavy rainfall. Dry Extreme 2030 Climate Change Scenario – Expected Water Quality Changes (red parameters indicate a decline in condition) ↑ Water temperature ↓ Dissolved oxygen ↑ Algal Blooms ↓ Nutrient loads (where no signif. point sources) ↑ Salinity 3.4.1.2. ↓ Turbidity Wet Extreme The ‘wet climate’ scenario is likely to affect water quality primarily by increasing pollutant loads from runoff, soil erosion, flash flooding and stormwater. Analysis of historical water quality conditions in some ‘representative’ rivers in the MDB has shown that water quality generally improves in ‘wet years’ (defined as the 90th percentile in river flows corresponding to the water quality record) (see Appendix A). The diurnal and seasonal water temperatures are less variable when river flows are higher due to the larger mass of water. Dissolved oxygen levels are generally higher in wet years due to lower temperatures and more aeration in flowing systems. However, during summer dissolved oxygen levels can also decline in wet years which may be due to the entrainment of organic matter on the floodplain leading to blackwater events – this however typically follows extended dry periods. Salinity levels are also lower during wet years because of the dilution of groundwater inputs with fresh surface water runoff. This is the case in both the Darling and Wimmera Rivers in wet years. Nutrient and turbidity loads may increase in rivers and reservoirs due to increased runoff (nonpoint sources) from agriculture, stormwater drains and roads. Increases in turbidity are significant during wet years, compared to dry years in the Darling River and compared to both dry and ‘normal’ years in the Wimmera River. Soil erosion is also likely to contribute to sediment loads if storms and flash flooding become more frequent. Erosion and increased runoff is particularly likely following bushfires in the catchment, which are also predicted to increase with climate change. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 18 Literature Review Wet Extreme 2030 Climate Change Scenario – Expected Water Quality Changes (red parameters indicate a decline in condition) ↓ Water temperature ↓ Salinity ↓ Algal Blooms 3.4.1.3. ↑ Dissolved oxygen ↑ Turbidity ↑ Nutrient loads Interactions of wet and dry sequences Antecedent conditions, weather sequences and the interactions of flow components (e.g. winter high flows, followed by summer low flows) are important factors that either increase or decrease the likelihood of water quality decline within waterways. Two pertinent examples are blackwater events and bushfire-related water quality impacts. Blackwater events are a dark discolouration of the water column usually associated with high concentrations of dissolved organic matter and low dissolved oxygen levels. These events typically occur when organic matter (e.g. leaf litter) on the floodplain becomes entrained in the water column in warm, slow-flowing conditions. Blackwater events cause deoxygenation of the water column, and the release of tannins at toxic concentrations, leading to fish kills and other ecological impacts. The time since the last flood is an important determinant of the quantity of accumulated organic matter on the floodplain and within the channel margin. The period of time between high flows and floods may increase under the ‘dry extreme’ climate change scenario, thereby increasing the likelihood and potential severity of blackwater events from any flow increases. Bushfires, followed by intense rainfall events, present a high risk of severe water quality impacts. Climate change scenarios suggest that there could be increasing frequency of fire weather in the future, potentially leading to more frequent and intense bushfires under the ‘dry extreme’ climate change scenario. Bushfires present a risk to water quality when they are followed by intense rainfall events. This generates bushfire-laden runoff, rich in nutrients, organic matter and suspended solids, which can dramatically decrease water quality by lowering dissolved oxygen levels (though organic matter decomposition), extremely high turbidity and follow-on effects such as algal blooms. The period of time between the bushfire and the rainfall event, and the intensity of the rainfall event, determines the severity of impact. After 3-6 months, the vegetation begins to regrow and can filter the runoff prior to it entering the waterway. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 19 Literature Review 3.5. Conclusions Impacts to surface water quality arising from climate change may occur directly through increasing surface temperatures and also indirectly through changes in catchment hydrology and surrounding land-use. Both the Dry Extreme and Wet Extreme 2030 climate change scenarios present a risk to water quality in rivers, reservoirs and wetlands in the MDB. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 20 Literature Review 4. Impacts of Climate Change on Groundwater Quality 4.1. Introduction Groundwater resources are less susceptible than surface water to short term climate variability; they are more affected by long-term trends as they are buffered by their sometimes large storage volumes. Relative to surface water, very little research has been undertaken to determine the sensitivity of aquifers to changes in critical input parameters, such as precipitation and runoff (Allen et al., 2004; Woldeamlak et al., 2007; Brouyere et al., 2004; Gleick, 2000) despite the fact that groundwater constitutes approximately 16 % of total water use in the MDB (CSIRO, 2008). Changes in regional temperature and precipitation have great implications for all aspects of the hydrologic cycle. Variations in these parameters determine the volume of water that reaches the land surface, evaporates or transpires back to the atmosphere, becomes stored as snow or ice, infiltrates the groundwater system, runs off the land and ultimately becomes baseflow to streams (Allen et al., 2004). Therefore, as part of the hydrologic cycle, groundwater systems will be affected by changes in recharge (i.e. precipitation and evapotranspiration) potentially by the changes in the nature of the interactions between groundwater and surface water systems and changes in use related to irrigation. 4.2. Groundwater quality drivers 4.2.1. Watertable Elevation The elevation of the shallow aquifer watertable is one of the primary drivers of groundwater quality in the Murray Darling Basin. The elevation of the watertable is attributed to many groundwater quality issues, including; Dryland salinity Groundwater salinity Concentration of pollutants Changes in watertable elevation are linked to landuse changes. For example, the issue of dryland salinity in Australia is associated with clearing of perennial vegetation in agricultural regions and replacement with annual crop and pasture species. This change in landuse has allowed more rainfall to remain unused by the plants, to enter the groundwater system and to ultimately elevate the watertable. The depth to watertable is also important in the timing of changes in groundwater conditions. The effects of change in the water balance as felt at the land surface is lagged when recharge has to SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 21 Literature Review traverse large unsaturated zones. That is, it can sometimes take long periods of time (greater than 100s of years) for infiltration to pass beyond ground level to eventually reach the watertable. Where large lag times in recharge occur, the timing of changes is affected. In some cases, climate change impacts may not be felt at the watertable for some substantial time into the future. 4.2.2. Influence of water balance on water quality The hydrologic cycle represents the continuous movement of water between the atmosphere, the Earth’s surface (glaciers, snowpack, streams, wetlands and oceans), soils, and rocks. The hydrologic cycle is driven by solar energy that heats the Earth’s surface and causes water from the surface to evaporate, sublimate and transpire. Water is transported from the atmosphere, back to the Earth’s surface as precipitation, falling as either rain or snow (SKM, 2009). Exchange of atmospheric water to groundwater can occur via infiltration of rainfall or snowmelt through the soil profile. Water may also run off the Earth’s surface and infiltrate to groundwater via streams, channels and wetlands. These processes, by which water from the surface, enters the groundwater system is called recharge. In detail, the process whereby water moves across the land surface is termed infiltration, where it moves past the base of the root zone it is called deep drainage (or root zone drainage) and where it crosses the watertable to groundwater it is termed recharge. Loss of groundwater to the atmosphere occurs through the process of evapotranspiration. This includes direct evaporation of shallow groundwater and transpiration by vegetation. Groundwater may also flow into streams, springs, wetlands, oceans, or be extracted via groundwater pumping for human use. The process by which water is removed from groundwater is called discharge. The difference between recharge and discharge determines the volume of water in groundwater storage. Any variations in climate have the potential to affect recharge, discharge and groundwater quality, either directly, or indirectly. An example of a direct impact would be reduced recharge due to a decrease in precipitation. An indirect impact would be a reduced risk of dryland salinity, due to reduced watertable elevations. Groundwater quantity, and quality can also be affected by water use and land use change. Examples include changes to groundwater pumping regimes, damming of rivers, clearing of woody vegetation and conversion of dryland agriculture to irrigation. As the climate changes, these cycles are susceptible to change, affecting the quantities, and distribution of water throughout the cycle. These effects are discussed below, along with the water quality implications of these changes. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 22 Literature Review 4.2.3. Other drivers of groundwater quality Anthropogenic drivers include any changes to the quality of recharging water, and changes wrought by anthropogenic-driven processes within the aquifer. The latter relate primarily to changes caused by extraction. The quality of recharging waters can be affected by a large range of processes, but are usually related to irrigation or urban development. 4.3. Climate Change impacts on groundwater quality 4.3.1. Direct impacts on water balance Groundwater recharge can occur in a diffuse form from precipitation via the unsaturated zone or it can occur locally from surface water bodies. The primary climatic driver for groundwater recharge is precipitation. Temperature and CO 2 concentrations are also important as they affect evapotranspiration and therefore the portion of precipitation that reaches the aquifer. Other factors also affect groundwater recharge, including; land cover, soil type, geology, topographic relief and the type of aquifer. 4.3.1.1. Precipitation Beare & Heaney (2002) examined the impacts of climate change on the hydrological cycle, particularly stream and groundwater flows, water quality and irrigated agriculture in Australia’s Murray Darling Basin. A simulation model was used to investigate the impact of changes in precipitation and evapotranspiration for two of the climate scenarios developed by the Intergovernmental Panel on Climate Change. The scenarios included a decrease in precipitation and an increase in evaporation over much of the Murray-Darling Basin. This study found that under both of the climate scenarios the impact of climate change on the diffuse recharge component of the hydrologic cycle was a reduction in recharge to the groundwater system and a general lowering of watertable elevations. A study by Woldeamlak et al. (2007) focused on the effects of climate change on the water balance and groundwater system of a sandy aquifer near Brussels. A wet, cold and dry scenario was considered. For the dry scenario, recharge was the most sensitive parameter and decreased for all seasons. More water was lost than could be replenished due to low precipitation and high evapotranspiration, especially by forests. This led to decreases in annual groundwater levels by as much as 3 m in the aquifer. The consequences of the reduced groundwater levels were considered significant, as such declines had the potential to reduce water availability to crucially low levels for both aquatic life in wetlands and riverine ecosystems. Furthermore, the prolonged dryness could eventually result in complete alteration/disappearance of short-rooted plant populations. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 23 Literature Review Brouyere et al. (2004) focused on the impact of climate change on the hydrological cycle in the Geer Basin in Belgium. Belgium has a similar climate to Australia, where direct percolation of rainfall occurs in the recharge period and slows when soil moisture deficits appear during the dryer months of the year. In such climates, the affects of climate change usually mean there is an increase in winter rainfall, albeit, the recharge season is usually shorter. The impact of climate change on groundwater levels in the Geer Basin did not cause a seasonal fluctuation of groundwater levels; instead the impact on groundwater levels was a ‘monotonic’ decrease with time. This was considered the result of the thick unsaturated zone that smoothed any seasonal fluctuations. Kuo-Chin Hsu et al. (2007) used numerical modelling to investigate the response of the groundwater systems of the Pintung Plain in southwestern Taiwan, to climate change. In this region, the steep topographic relief means that most of the precipitation becomes runoff and drains to the ocean in a short time. The impacts of climate change indicated that both the amount of annual precipitation and the number of days of precipitation decreased under the climate change modelling scenario. 4.3.1.2. Recharge via Irrigation Returns Ficklin et al. (2010) considered the sensitivity of groundwater recharge under irrigated agriculture to changes in climate, CO 2 concentrations and canopy structure, in the semi-arid Central Valley of California, using Hydrus 1D numerical modelling. It was noted that in semi-arid regions, accurate estimates of recharge and evapotranspiration are important for management of scarce water resources. The following conclusions were made from the modelling results; Increased daily temperature led to increased evapotranspiration, resulting in an increased use of irrigation water that was potentially available for groundwater recharge; Increased atmospheric CO 2 concentration increased crop water use efficiency, leading to decreased evapotranspiration rates and a reduction in the amount of water needed for irrigation; and Increased atmospheric CO 2 concentration increased plant growth rates resulting in more irrigation needed earlier in the season. Although the increase in atomospheric CO2 concentrations leads to both a decrease and an increase in irrigation water, the overall impact is a decline in groundwater recharge. Ficklin et al. (2010) concluded that the effect of decreased evapotranspiration from increased water use efficiency may have a greater effect on groundwater recharge than the increase in irrigation water from increased plant growth. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 24 Literature Review 4.3.1.3. River Leakage Allen et al. (2004) modelled the sensitivity of the Grand Forks aquifer in south-central British Columbia, to changes in recharge and river stage to climate change scenarios for the region. The Grand Forks aquifer is a highly productive alluvial aquifer situated in a bedrock valley, approximately 4 km wide near its centre and narrower at both ends. The area is characterised by a semi-arid climate. The results of the modelling indicated that the variations in recharge to the aquifer have a much smaller impact on the groundwater system than changes in river-stage elevation of the rivers that flow through the valley. Annual recharge to the narrow alluvial aquifer is limited and the simulations of high and low recharge showed there was little impact on changes to hydraulic head. However, an assessment of changes in river-stage elevation provided an insight into the processes that control aquifer recharge and the seasonal availability of groundwater in the valley. The aquifer was highly sensitive to changes in river stage. For the scenario of 50 % higher than flood conditions, the watertable averaged 3.5 m higher than current levels, for the scenario of 50 % lower than baseflow conditions; the watertable was 2.1 m lower than the current levels. The results are entirely consistent with what is expected of a narrow alluvial valley aquifer situated in a bedrock valley, with river stage providing the dominant control on aquifer water levels. 4.3.1.4. Evapotranspiration Bouraoui et al. (1999, cited in Woldeamlak et al., 2000) reported that the substantial reduction in groundwater recharge to an aquifer in Grenoble (France) was almost entirely attributed to the increase in evapotranspiration during the recharge season under CO 2 doubling scenarios. 4.3.1.5. Discharge to Streams The impact of reduced groundwater recharge and increased evapotranspiration under a dry climate change scenario, is reflected by a reduction in groundwater discharge and lower groundwater levels. Beare & Heaney (2002) noted that a substantial delay is likely to occur before the reduction in recharge is fully reflected in a reduction in groundwater discharge. The length of this delay will depend on the hydrological characteristics of the groundwater flow system. 4.3.1.6. Groundwater pumping Woldeamlak et al. (2007) predicted that the effects of climate change and in particular summer dryness, would lead to an adjustment of irrigation requirements that would ultimately lead to more groundwater pumping. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 25 Literature Review Moustadraf et al. (2008) looked at an aquifer in a semi-arid region of Morocco. Numerical modelling of the aquifer showed that the groundwater resources of this system were less sensitive to variations in precipitation and that the severe degradation of the aquifer was in fact related to intensive pumping during the periods of drought. This pumping induced seawater intrusion into the aquifer and consequently wells were abandoned due to salt water contamination. 4.3.2. 4.3.2.1. Indirect impacts on water balance Agricultural water management The indirect implications of climate change were recognised by Ficklin et al. (2010) in terms of the response by resource managers and also the response by irrigators. In terms of resource management, changes to water allocation to meet farmer’s needs were predicted, given that a shift in irrigation timing due to changes in plant growth and a decrease in evapotranspiration could occur. In terms of the irrigators, it is likely that the planting regime could be altered to account for the increase in plant growth rates (given that crops grow faster under higher average daily temperatures). Although faster crop development may occur and result in a reduced growing season water demand, it is likely that multiple cropping will occur and hence the annual water demand may increase. The Beare & Heaney (2002) study of the Murray-Darling Basin also discussed the likely indirect impact of climate change associated with improved water use efficiency, coupled with reduced water availability. They found that a reduction in the volume of irrigation excess water to recharge the groundwater system was likely, given a reduction in surface water runoff, groundwater discharge and drainage to the river. 4.4. Potential impacts to groundwater quality in Murray-Darling Basin 4.4.1. Current groundwater quality issues The Bureau of Rural Sciences produced a series of groundwater quality assessments from catchments across Australia, including assessments of the alluvial aquifers in the Border Rivers Catchment (Qld/NSW), the Upper Shepparton Formation aquifers in the Cobram Region (Victoria), the Nagambie-Mangalore and Kyabram-Tongala areas in the Goulburn Catchment (Victoria) and the shallow aquifers in the Murray Region (NSW). This next section is largely based on the findings of these groundwater quality assessments. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 26 Literature Review 4.4.1.1. Sodic Soils Sodic soils occur in arid to semi-arid regions and are characterized by a high concentration of sodium in their cation exchange complex. Sodic soils are structurally unstable, exhibiting poor physical and chemical properties, which impede water infiltration, water availability, and ultimately plant growth. The western and the south-central areas of the Border Rivers Catchment are characterised by high and very high sodium hazard (Please et al., 2000). In the south-central area, the high sodium is attributed to upward migration of sodium-rich waters along the Peel Fault Zone. Salinisation and soil sodicity was also recognised as a significant management issue for the Upper Shepparton Formation aquifers in the Cobram region (Ivkovic, 2001). More than one third of the samples collected indicated a high to very high sodium hazard in this area. The medium Sodium Adsorption Ratio (i.e. the suitability of water for use in agricultural irrigation) in the Nagambie-Mangalore region was 14.2. Eleven of the sixteen samples indicated very high sodium concentrations that were considered unsatisfactory for irrigation purposes. In the shallow aquifers of the Murray region, 85 % of samples indicated a very high sodium hazard. 4.4.1.2. Trace Metals High metal concentrations, well above ANZECC Irrigation Water Guidelines were identified in the Border Rivers Alluvium Catchment. High concentrations were also detected in the Murray region, around Cobram and in the Goulburn Catchment. The correlation between high salinity groundwater and high trace metal concentrations was linked to the effects of evaporation increasing the concentration of these elements, in all of these areas. 4.4.1.3. Herbicides Pesticides were detected in 22 % of the shallow groundwater samples from the Kyabram-Tongala study area. The compounds detected were all herbicides and the contamination was linked to the application of herbicides on irrigated dairy pastures and in the horticulture industry (Watkins et al., 1999). Herbicides were also detected in 48 % of groundwater samples in the upper Shepparton aquifer in the Cobram region. In both of these cases the contamination of the shallow aquifers via pesticides, was considered to be fast and recent. This was indicated by the absence of degradation products. 4.4.1.4. Microbiota Faecal Indicator Bacteria (FIB) was recovered from 22 % of groundwater samples in the KyabramTongala region. The FIB was related to herds of dairy cattle grazing on irrigated pastures. FIB was SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 27 Literature Review also recovered from 19 % of samples in the Cobram region and was associated with septic tank effluent and livestock faeces. 4.4.1.5. Dryland Salinty Dryland salinity is one of Australia’s most serious environmental and resource issues. Most agricultural land in Australia is characterised by naturally high levels of salt in the subsurface. Prior to European settlement, groundwater levels in Australia were in a long-term equilibrium. However, the land has since been cleared of the perennial vegetation in agricultural regions and replaced with annual crop and pasture species that allow more rainfall to remain unused by the plants and to enter the groundwater (Walker et al., 1999). Two million hectares of agricultural land is affected by shallow watertables, with the most serious problems occurring in Western Australia and to a lesser extent, South Australia and Victoria. In NSW, dryland salinity is a major natural resource management issue, however most areas of the upland Murray-Darling Basin appear to be in a new hydrological equilibrium and the future trends estimated in the 1999 Salinity Audit have been substantially reduced (DECC, 2009). 4.4.2. 4.4.2.1. Potential climate change impacts Dryland Salinity There are two potential impacts of climate change on dryland salinity (John et al., 2005); 1) A reduction in rainfall may result in less groundwater recharge and consequently less dryland salinity risk and water logging 2) If reduced winter rainfall is offset by increased summer rainfall, dryland salinisation may actually increase In the Adelaide Mount Lofty Ranges, the reduced groundwater recharge under climate change conditions is recognised to potentially decrease the salinity risk, due to reduced watertable elevations. However, it was recognised that the poor water use in agricultural fields could exacerbate recharge (AMLR NRM Board, 2007). The simulation modelling conducted by Beare & Heaney (2002) indicated that some parts of the Murray-Darling Basin would be affected by high watertables. High watertables have the ability to reduce agricultural yields, damage transport, communication and other infrastructure through water logging and by depositing salt in the landscape (i.e. dryland salinity). The extent of the damage of the high water tables is highly dependent on the salinity of groundwater being mobilised into the landscape. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 28 Literature Review 4.4.2.2. Pollutants In the event of an increase in rainfall intensity, pollutants (i.e. high concentrations of sodium, trace metals, herbicides and microbiota) will be increasingly washed from soils to water bodies and where recharge to aquifers occurs via these surface water bodies, groundwater quality is likely to decline. Furthermore, elevated watertables could have negative consequences on crops and natural vegetation in that area. Where recharge is projected to decrease, water quality may again decline, due to lower dilution. 4.4.2.3. Surface Water Quality The Lower reaches of the Murray River have been analysed in terms of the potential impacts of climate change on Lower Murray floodplain health (Connor et al., 2010). There is a significant salinity issue in the Lower Murray region because of the highly saline groundwater that is hydraulically connected to the river. Connor et al. (2010) found that the reduction in precipitation and the local adaptation of irrigators to increased water demand due to climate change impacts, may have a positive outcome in this area. The positive impact relates to the lower watertable elevation and subsequent lower volume of groundwater discharge to the floodplain. However it should be noted that although there is less risk to the floodplain due to lower watertable elevations, the reduced river flows predicted for climate change scenarios means that the inundation of the floodplain required to maintain ecological health, is unlikely to be met. Beare & Heaney (2002) noted that in some parts of the Murray-Darling Basin, a decline in discharge of saline groundwater does not provide a benefit to stream salinity, as the reduction in surface water flows that are available to dilute the existing salt loads, is too great. In other parts of the Basin - in particular, the irrigation areas- salinity benefits were recognised. Irrigation areas are characterised by saturated soil profiles, which means that a change in recharge leads to a reduction in discharge relatively quickly. In these areas salinity trends tend to increase only slightly or even decline as the volume of irrigation water applied reduces and this reduction is quickly translated into a reduction in groundwater discharge. In other words, in such areas the impact of reduced surface water flows are offset by reduced groundwater discharge, generating water quality benefits in the Murray River. 4.5. Conclusions and Recommendations The implications of climate change on groundwater resources are likely to be delayed and subdued relative to the impacts on surface water resources, given that groundwater systems are more susceptible to long-term trends and in some cases have a large volume of water in store to act as a buffer to such changes. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 29 Literature Review Groundwater pollutant issues (i.e. high concentrations of sodium, trace metals, FBIs etc) have been identified in some areas of the Murray-Darling Basin, albeit these issues tend to occur on a local scale and have not impeded the use of groundwater for agriculture use, to date. The impacts of climate change on these types of groundwater quality issues are likely to be negative. In the case of increased precipitation, the increased runoff is likely to concentrate pollutants in groundwater. If precipitation decreases, the lower dilution may again, lead to an increase in pollutant concentration. Counter this, though, is that under drier climates the depth to watertable will increase and the potential to pollute shallow groundwater will also decrease. Thicker unsaturated zones will also act to ameliorate any potential pollution. However, overall, even at their worst, these impacts are likely to be small. The potential for climate change impacts to result in salt water intrusion and subsequent groundwater quality deterioration is recognised in various studies of climate change around the world (Kuo-Chin Hsu et al., 2007; Moustadraf et al., 2008). The risk of this impact is negligible in terms of the Murray-Darling-Basin, as it is primarily an inland basin and the only part of the Basin that is characterised by coastal aquifer systems, is where the Murray River meets the Southern Ocean in South Australia. The most significant impacts of climate change on groundwater quality in the Murray-Darling Basin are the impacts on dryland salinity and river salinity. Dryland salinity is one of Australia’s biggest groundwater quality threats and climate change has the potential to influence one of the primary factors in its generation; watertable elevation. The impact of climate change on dryland salinity will vary across the basin and will depend on the net effect of changes in the hydrological cycle, the response time of the groundwater flow system and the rate of recharge in each catchment (Beare & Heaney, 2002). Rising river salinity is a major water quality issue in the Murray-Darling Basin, particularly in the areas of the Victorian Mallee and South Australian Riverland. In these areas groundwater table elevations are critical, as higher groundwater levels, correspond to more saline groundwater discharge to the river. Climate change implications are likely to have the greatest impacts in this area, however the impacts may vary as the groundwater system adjusts to the altered hydrologic regime. In the short-term, there will be little response in the groundwater levels due to reduced precipitation and the likely impact of climate change will be an overall decline in surface water quality, due to the immediate reduction in surface water runoff and the less water available to dilute existing levels of saline groundwater discharge. In the longer term however, the implications of climate change could be positive. Reduced precipitation and increased evapotranspiration could lead to the lowering of watertables and a reduction in saline groundwater discharge to rivers. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 30 Literature Review 5. Water Quality in the Murray-Darling Basin The environmental values (e.g. irrigation, drinking water, recreation, aquatic ecosystems, etc.) of the water resources in the Murray-Darling Basin are all strongly dependent on good water quality. The primary drivers of water quality throughout the basin are catchment hydrology and land use. This section provides a general summary of water quality issues in the basin as highlighted through a general literature search and specialist workshop, and then provides a region-by-region summary of the water quality dependent values, their threats and general trends. 5.1. Workshop On the 17th May 2010, Sinclair Knight Merz hosted a workshop for external specialists to discuss current and future water quality issues in the MDB Murray-Darling Basin (MDB). Fifteen water quality specialists familiar with the MDB attended a full day workshop in Canberra (Table 1-1). Table 5-1 Invited participants to the workshop ATTENDEES APOLOGIES Name Organisation Name Organisation Richard Cresswell CSIRO Richard Davis NWC Klaus Koop DECCW Phil Cole MDBA Tony Jakeman ICAM Michael Wilson MDBA Mike Grace Monash Uni Alastair Buchan MDBA Tim Stubbs Wentworth Group Pat Feehan Feehan Consulting Don Bursill Urban Water Innovations Barry Hart Water Science Brian Bycroft MDBA Phil Price LWA Alice Shields MDBA Richard Bush SCU Kris Kleeman MDBA Bill Maher Uni of Canberra Jason Alexandra MDBA Mathew Maliel MDBA Ray Evans SKM Rai Kookana CSIRO Tony Church SKM Darren Baldwin MDFRC Simon Treadwell SKM John Williams NSW NRC Nick Schofield SKM Brian Lawrence MDBA Bonnie Atkinson SKM The discussion of the workshop centred on current and emerging water quality issues in the northern and southern parts of the basin. It then focussed specifically on potential future water quality issues with reference to dry extreme and wet extreme future climate change scenarios. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 31 Literature Review 5.2. Current water quality issues The water quality in the Basin is declining with rising salinity, high nutrient and suspended sediment loads, cold water pollution and low dissolved oxygen levels. Rising salinity is one of the major issues facing the Murray-Darling Basin (Chartres et al., 2003). Salinity levels have risen in almost all of the Basin’s rivers, particularly in the upland catchments in NSW (Chartres et al., 2003). Salinity levels increase along the River Murray, however, water diversion for irrigation and salt interception schemes have been successful recently in reducing salt loads in the basin overall. High nutrient and suspended solids loads are widespread stressors on the environmental health of waterways in the entire Murray-Darling Basin (NLWR, 2001). The only reaches where there are no major water quality effects were in the upper parts of the catchments and the western Queensland part of the Murray-Darling Basin (NLWR, 2001). Most of the liberated sediment loads have been generated in the upland and midslope areas, but the impact is seen in lowland rivers, weir pools and reservoirs where the sediment is stored and high nutrients lead to algal blooms. Algal blooms have always been present in the river system and blooms are a natural phenomena. In 1878 the blue-green algae, Nodularia spumigena, bloomed in Lake Alexandrina causing the death of animals that drank the water. Blooms of blue-green algae in the River Murray in South Australia have been recorded intermittently since records began in 1947. In the Darling River in 1991, a toxic bloom of blue-green algae occurred over a distance of 1000 km and caused the New South Wales government to declare a state of emergency. During recent very low flow periods, blooms are probably getting more intense and possibly becoming more frequent due to reduced flows and high nutrient inputs. The decay of algal blooms are associated with low dissolved oxygen levels, which can have catastrophic ecological effects. Cold water releases from bottom water of large dams also remains a significant problem hindering the recovery of native fish populations in the Murray-Darling Basin (Boys et al., 2009). For example, in the Macquarie River during summer, when ambient water temperatures average around 25°C, the temperature of water in the river downstream of Burrendong Dam varies around 13°C (Astles et al., 2003). These suppressed temperatures persist for over 300 km downstream. Other basin-examples of cold water pollution are downstream of Lake Eildon in the Goulburn Basin, and the Keepit Dam in the Namoi Basin. It has been estimated that up to 3000 km of river channel in the Basin is affected by cold water pollution (Gehrke et al., 2003). A summary of the current water quality issues in the north and southern parts of the basin is provided below under the categories of physical, chemical and biological parameters. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 32 Literature Review 5.2.1. Northern Basin The northern basin was loosely defined as those regions north of the Lachlan River region, which were categorised on the basis of the seasonality of rainfall. It includes those rivers in southern Queensland and northern New South Wales. The northern basin is less regulated than the southern part of the basin. The current water quality issues identified in the workshop for the northern part of the basin are related to anthropogenic activities in the regions (Table 5-2). Table 5-2 Physical, chemical and biological water quality issues in the Northern Basin Physical pH Although highly localised, patches of acid sulfate soils (ASS) and acid mine drainage have been noted in the northern basin. The Murray-Darling Basin generally has a low probability of occurrence of ASS. However, there are patches of high probability in the lower Murray region. Water temperature Cold-water pollution is an issue in rivers downstream of major storages. There have been noted impacts on recreation as well as native fish and macroinvertebrates. Turbidity/Total Suspended Solids Turbidity and high suspended solids loads are natural water quality characteristic of the northern basin due to the intense nature of rainfall. Loads have increased recently due to stream bank collapse (e.g. Namoi catchment), exacerbated by extended low flows and changes to the flow regime. High turbidity loads are related to high nutrient and pesticides loads, particularly high phosphorus loads in the upper Namoi. There is a general trend of low turbidity/low nutrients in the eastern basin tending towards high turbidity/high nutrients on the western side of the basin. Salinity causes a notable decline in turbidity and the resultant rise in algal growth because of the improved light regime. Chemical Electrical conductivity Salinity is an issue in central-western NSW, particularly in the Condamine, Namoi and Border Rivers regions. The disposal of saline water from coal seam gas production is an emerging issue, which may affect the salinity of rivers in involved areas. Dissolved oxygen Dissolved oxygen is critical for maintaining refuge pools in the ephemeral rivers in the northern basin. Algal blooms and large accumulations of organic matter in wetlands and channel margins present a risk for low dissolved oxygen effects. Nutrients High nutrient loads are related to high turbidity loads. The tablelands and slopes in reasonable water quality condition, but areas on tertiary basalt are high in P (e.g. Pell, Namoi). Reservoirs in northern tablelands are subject to intense blue green algal blooms driven by naturally high phosphorus in some catchments. Dissolved organic carbon/Biological oxygen demand Dissolved organic carbon (DOC) concentrations are very high (4.5 - 15 mg/L) compared to overseas equivalents (1.5 - 5.0 mg/L). However, the DOC is also naturally highly refractive due to the nature of the vegetation (i.e. Eucalyptus sp.). DOC is a key driver of drinking water treatment requirements. It can increase due to fires and blackwater events in connected wetlands. Pesticides Pesticides are in high concentrations in regions with extensive cropping, particularly cotton farming in the north-western parts of the basin. Other: Heavy metals, such as arsenic, iron and manganese are at high levels in groundwater, which restrict the water usage. Sodium is also high in areas of the basin linked to the Great Artesian Basin. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 33 Literature Review Biological Algal counts Algal blooms are a recurring issue in the basin. They are linked primarily to declining flow and increasing nutrient loads and water clarity. Emerging water quality issues 5.2.2. Increasing river salinity due to reduced surface water inflows and rising groundwater salinity; Low dissolved oxygen levels under base flow and increasing incidence of stratification (thermal &/or saline); High nutrients and contaminants (including Endocrine Disrupting Chemicals (EDCs)) from an increasing proportion of stormwater, septic tank leakage or sewage treatment plant effluent in rivers; Southerly movement of toxic blue green algal species Nodularia; and The spread of thermally tolerant protozoans into South Australia’s water supply that can cause human disease. Southern Basin The southern basin included the regions south of and including the Lachlan River region. The River Murray is also categorised into the southern basin. These regions are situated in Victoria, Southern NSW and into South Australia. The southern basin is highly regulated compared to the northern basin. The current water quality issues identified at the workshop for the southern part of the basin are related to anthropogenic activities and the high level of flow regulation in these regions (Table 5-2). Table 5-3 Physical, chemical and biological water quality issues in the Southern Basin Physical pH The Parilla sands groundwater aquifer in northern Victoria and South Australia is naturally acidic. It is buffered when it enters the rivers, but where it is expressed at the surface-groundwater interface it is very acidic. Although highly localised, patches of acid sulfate soils (ASS) and acid mine drainage have been noted in the southern Basin. The Murray-Darling Basin generally has a low probability of occurrence of ASS. However, there are patches of high probability in the lower Murray region. Several wetlands along the River Murray have been disconnected during the recent drought, which has exposed acid sulfate soils. This presents a risk of acidity and heavy metals if the wetlands are flushed. Water temperature Cold-water pollution is an issue in rivers downstream of major storages that receive cooler water from snow melt. There have been noted impacts on recreation as well as native fish and macroinvertebrates, particularly in the Goulburn system downstream of Lake Eildon. There have also been instances of warm river pollution from environmental flow releases into dry river beds. Turbidity/Total Suspended Solids Turbidity is less of an issue in the southern basin than the northern basin, however, turbidity levels rise in response to natural and anthropogenic activities in the regions. Extremely high turbidity and organic matter loads were experienced in the Ovens region in response to heavy rainfall post the alpine bushfires in 2002/03. There has also been sand dumping in the lower Murray caused by people putting sand on clay banks to increase ease of access for recreation. Chemical Electrical conductivity Rising salinity is an issue in the southern basin predominately in wet periods when groundwater levels rise and interact more strongly with the river. EC levels decline during dry years. Saline stratification of deep pools occurs in the Campaspe and Wimmera SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 34 Literature Review Regions. Dissolved oxygen Algal blooms and large accumulations of organic matter in wetlands and channel margins present a risk for low DO effects. These DO issues manifest in weir pools and ephemeral/ low flow streams, but not in the large regulated rivers. Nutrients Nutrient levels in the southern basin are high. These high levels are attributed to agricultural activities in the catchment, such as application of fertilisers and high animal stocking rates. High nutrients lead to prolific plant growth and algal blooms, which occur in slow flowing or still water areas, such as weir pools and reservoirs. Sewage treatment plant effluent is also a source of nutrients in rivers that flow through urban areas. Large spikes in nutrient loads have followed major bushfires in the region, i.e. 2003 Canberra fires and 2002/03 Victorian Alpine bushfires. The nutrients are liberated from erosion, high organic matter loads, and atmospheric fall out (Water Studies Centre Study on Tambo/Mitta Mitta Rivers post 2002/03 Bushfires). Dissolved organic carbon/Biological oxygen demand Blackwater events, caused by high organic matter loads, have increased in frequency and severity in the Loddon River and also in wetlands connected to the River Murray (e.g. Barmah-Millewa Forest and Edward-Wakool System) from increased regulation, in particular the lack of overbank flows. Dissolved organic carbon (DOC) concentrations are very high (4.5 - 15 mg/L) compared to overseas equivalents (1.5 - 5.0 mg/L). However, the DOC is also naturally highly refractive due to the nature of the vegetation (i.e. Eucalyptus sp.). DOC is a key driver of drinking water treatment requirements. Pesticides Localised accumulation of pesticides has been noted in the sediments of weir pools, particularly in South Australia. Other: Iron and manganese levels have been high in reservoirs in the southern basin. Heavy metals, endocrine disrupting chemicals and pharmaceuticals from STPs and intensive animal industries are may also be impacting on aquatic ecosystems. Biological Algal counts Algal blooms are a recurring issue in the basin. They are linked primarily to declining flow and increasing nutrient loads and water clarity. Blue green algal blooms in weir pools along the River Murray are increasing in frequency and duration. The algal species composition has also changed towards a more thermally-tolerant and toxic species (Cylindrospermopsis sp.), previously only known to occur in the northern basin. Emerging water quality issues Increased incidence of toxic algal bloom species, Cylindrospermopsis sp. Irrigation modernisation will result in less outfalls and less watering of wetlands through channel leakage; Increasing river salinity due to reduced surface water inflows and rising groundwater salinity; Artificial flow regimes due to heavy regulation. Mismanagement of environmental flow deliveries may cause blackwater events, spikes in salinity and thermal pollution (hot and cold). Low dissolved oxygen levels under base flow and increasing incidence of stratification thermally tolerant protozoans into South Australia’s water supply that can cause human disease. (thermal &/or saline); High nutrients and contaminants (including Endocrine Disrupting Chemicals (EDCs)) from an increasing proportion of stormwater, septic tank leakage or sewage treatment plant effluent in rivers; SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 35 Literature Review 5.3. Future water quality issues The afternoon workshop discussion focussed on potential future water quality issues relating to wet extreme and dry extreme 2030 future climate scenarios in the Murray-Darling Basin. These scenarios were based on the dry and wet extreme 2030 scenarios modelled by the CSIRO sustainable yields project (CSIRO, 2008) 1, which predicted the changes in water availability in each region (Table 3-1). 5.3.1. General overview Water allocations and land management will play a vital role in determining the health of waterways in the MDB into the future. This is more the case in the southern basin, which is a heavily regulated system. Under a dry extreme 2030 scenario, where water becomes scarce, water delivery priorities and land management may shift towards protecting critical human needs as opposed to the environment in the southern basin. The northern basin is less regulated, however, the environment, particularly in the north-western ephemeral zones is harsh and vulnerable to climate change. It is expected that the natural catchment hydrology regime will be amplified under climate change, increasing the intense nature of rainfall generating erosion, and extending the periods of no flow putting pressure on the survival of biota in refuge pools. Regardless, the future water quality issues relating to a dry and wet scenario are expected to be relatively the same between the northern and southern MDB. A summary is presented in Table 3-2. Table 5-4 Potential water quality issues in the MDB under the wet and dry extreme 2030 climate change scenarios Parameter Wet Dry Physical pH - - Water Temperature - A very minor rise in alkalinity due to higher dissolved CO 2 , depending on the buffering capacity of the natural organic matter present. Low EC systems (uplands) are more vulnerable because of their lower buffering capacity. Acid sulfate soils will be less of an issue because of the more stable wet weather conditions. - Small increase in response to air temperature rise, but will be compensated by larger body of water to heat/cool in higher flow - - - A minor rise in alkalinity due to higher dissolved CO2, depending on the buffering capacity of the natural organic matter present. Low EC systems (uplands) are more vulnerable because of their lower buffering capacity. Drying of wetlands and river channels may expose ASS in localised areas, increasing the risk of acidity. The hot spots include the lower Condamine in north and the Edward/Wakool, Wimmera and lower lakes South). Large increase in response to air temperature rise, particularly during ‘heat-wave’ conditions. Diurnal variations in water temperature 1 CSIRO (2008) Water availability in the Murray-Darling Basin. . (ed^(eds, pp. 67pp. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project, CSIRO, Australia. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 36 Literature Review Parameter Wet Dry conditions. - Turbidity - More frequent large rainfall events could generate erosion, leading to increased turbidity levels. Runoff from diffuse sources, such as farms, roads, pavements and gardens will increase turbidity. - - will become more extreme due to smaller water mass to heat/cool in low flow conditions. Thermal stratification of reservoirs will occur earlier in the season, and persist longer. Disconnected or deep pools in slow-flowing rivers may thermally stratify. Cold-water pollution and warm-water pollution in regulated systems. Turbidity levels will be lower overall. Altered soil properties from intensive drying, followed by episodic rainfall events may generate increased erosion, and also increase storm-water contaminants loads in urban areas. Water clarity will be higher, leading to an increase in algal blooms in nutrient enriched systems. Bushfires, closely following by intense rainfall events, deliver high suspended solids loads. Chemical Salinity - - - Dissolved oxygen - Groundwater levels will rise and interact with surface systems causing saline groundwater intrusions. However, higher surface runoff will dilute groundwater inputs, and therefore the salinity will depend on the relative proportions of groundwater and surface water in rivers. Extreme recharge events may move saline groundwater and increase the potential for dryland salinity. Minor decrease with reduced solubility from the rise in water temperature, but will be mitigated by re-aeration from higher flows. - - - - Nutrients - Particle bound phosphorus loads will increase with erosion associated with heavy rainfall - Groundwater levels will drop and there will be less saline intrusions into surface systems. However, where there is groundwater interaction, the groundwater may be a higher proportion of the river flows due to lower surface runoff. Salinity will rise in groundwater fed, disconnected refuge pools, which may exceed the tolerance levels of waterdependent biota. Disconnected or deep pools in slowflowing rivers may salt-stratify. Decrease with reduced solubility from the rise in water temperature and slower flowing/still water conditions The range in diurnal variations will be more extreme due to increased primary productivity and community respiration rates with increasing temperatures. Lower flows and increased stratification (thermal or saline) will favour algal blooms and nuisance plant growth, with high oxygen drawdown during the night and also from algal/plant decomposition. Nutrient loads will generally be lower, due to lower runoff. However, episodic high rainfall events may deliver pulses SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 37 Literature Review Parameter Wet - Dry events. Irrigation drainage from agricultural areas will increase nutrients loads in the waterways. Higher loads of nutrients entering into water storages, causing eutrophication and algal blooms. - - - Organic Carbon - Leaf litter entrained from the floodplain and channel margins during high flows will increase dissolved and particulate organic carbon loads. - - Pesticides - - of nutrients that may drive eutrophication. Atmospheric fixation of nitrogen depends on thunderstorm intensity/frequency, but probably a small contribution in agricultural catchments Sewage treatment plant effluent becomes a higher proportion of the stream flow, thereby increasing nutrient concentrations. Bushfires, closely following by intense rainfall events, deliver high loads of nutrients. High litter fall into channel from droughtstressed vegetation, such as red river gums. High organic loads multiply microbial community numbers, thereby increasing processing rates and diurnal variability in DO and pH. Bushfires, closely following by intense rainfall events, deliver high loads of organic carbon. More frequent large rainfall events could generate erosion in agricultural areas, leading to pesticide liberation. Runoff from diffuse sources, such as cropping and gardens will increase pesticide loads. - Pesticide concentrations increase from a lack of diluting surface flows in agricultural systems Nutrient loads will increase; however, water clarity from higher turbidity and higher flows in rivers and storages will reduce the frequency and duration of algal blooms. - Algal blooms will increase in frequency and duration due to still and/or slowing flowing conditions in reservoirs, rivers, disconnected pools and wetlands. Higher water clarity means light will penetrate deeper into the water column stimulating growth of algae and nuisance aquatic plants. Lower dissolved oxygen levels in lower layers of thermally or salt-stratified water bodies will release phosphorus, fuelling toxic blue-green algal blooms. Biological Algae - - - Pathogens - - Increase loads due to sewer exfiltration from overloaded pipes in urban areas and seepage from septic tanks Runoff from diffuse sources, such as farms, roads, pavements and gardens will increase pathogen loads. - Sewage treatment plant effluent, septic tank seepage and stormwater will constitute a higher proportion of river flows, which will increase pathogen concentrations. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 38 Literature Review 5.4. Region by Region The MDB has been divided into 17 regions for this project (Figure 5-1). The regions are the major tributaries in the MDB and reflect the regions used in CSIRO (2008l) as well as existing river system models and water sharing plan areas. Figure 5-1 MDB regions after (CSIRO, 2008l) 5.4.1. 5.4.1.1. Barwon-Darling Overview The Barwon-Darling Region is in northwestern New South Wales and comprises 13 % of the Murray Darling Basin (CSIRO, 2008a). This region is based around the Barwon, which changes name to the Darling River. The river flows south-west from Collarenebri in the north-east to SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 39 Literature Review Wilcannia in the south-west. Generated runoff in this region is very low compared with the high inflows it receives from its tributaries in the northern part of the basin, including the MacquarieCastlereagh, Namoi, Gwydir, Border Rivers and Condamine-Balonne River regions. The BarwonDarling plays an important role in connecting the northern and southern regions in the Basin. The predominant land-use in the region is dryland pasture for beef and sheep (CSIRO, 2008a). Almost one-third of the land area remains as native vegetation, including woodlands, forests, chenopod shrublands and native pastures. The recent climate (1997-2006) has been similar to the long-term average climate in the BarwonDarling Region (CSIRO, 2008a). Future development of farm dams in the region is expected to reduce runoff by less than 0.5 % by 2030. Groundwater extraction is expected to grow to 240 GL/year, from 10 GL/year, to be over 50 % of the average total water use in the region (CSIRO, 2008a). Climate change is expected to reduce surface water availability by 8% and increase surface water use by 2 % (CSIRO, 2008a). 5.4.1.2. Values The Barwon-Darling River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in poor condition. Over half of the predicted native species were not found. However, native fish were abundant and the intrusion of alien species was moderate compared to other valleys (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community declined in condition from moderate/good in the upper zone to poor in the lower and middle zone. The communities at most sites were impoverished and lacked many disturbance-sensitive families. Ecosystem health: Overall ecosystem health in the Barwon–Darling river is ‘poor’ (Davies et al., 2008). Nationally important wetlands: Talyawalka Anabranch and its distributary Teryawynia Creek receives water from the Darling River near Wilcannia and returns water in the Lower Darling River downstream of Menindee. This large wetland are consists of a series of lakes, which provide habitat for waterbirds and Black Box and River Red Gum vegetation communities (CSIRO, 2008a). These lakes also have aboriginal heritage values. Current and future developments in the Barwon-Darling Catchment, coupled with climate change, will affect the frequency and duration of important flows to the Talyawalka system. Water Supply SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 40 Literature Review Irrigation: This region uses approximately 3% of the surface water diverted for irrigation in the MDB. Stock and domestic: There are no major public water storages in the region, other than lowlevel weirs to provide domestic and stock supply during zero-flow periods (CSIRO, 2008a;Davies et al., 2008). There are 15 such weirs on the Darling upstream of Menindee, which causes ‘ponding’ of up to 640 km of the river. Most diversions are opportunistic harvesting of high flows. Tourism The Darling River is a major drawcard for tourist. The ‘Darling River Run’ is a 700 km tourist route that follows the river from Bourke to Wentworth and attracts a steady stream of visitors each year (Western CMA, 2010). 5.4.1.3. Threats The water quality and flows in the Barwon-Darling River is under threat from (Western CMA, 2010): Diversions of water for irrigation, industrial and domestic uses; Uncontrolled stock access fouling water with waste and causing riverbed erosion; Polluted run-off from towns; Salinity and blue-green algae; and High turbidity and sedimentation. 5.4.1.4. Water quality summary Major water quality issues for the Barwon-Darling River are high levels of turbidity, nutrients and salinity, as well as the occurrence of algal blooms and contamination with agricultural pesticides (Western CMA, 2007). High salinity levels and blue-green algal blooms are most common during cease to flow and low flow periods. This has restricted water use for domestic, stock and recreational purposes (Western CMA, 2007). In November and December 1991, the world’s largest recorded riverine algal bloom was recorded for 1000km along the Barwon-Darling River. It extended from Wilcannia to Mungindi and a State of Emergency was declared in NSW. The Barwon–Darling River receives the majority of its water from the tributary streams that form that northern part of the MDB. The water quality depends largely on both the quality and quantity of water flowing from these upstream sources (Western CMA, 2007). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 41 Literature Review Salinity in the Barwon–Darling is highly variable and can range from 200 µS/cm to more than 3000 µS/cm (Western CMA, 2007). The long-term median and 80th percentile electrical conductivity (EC) levels at Mungindi are 257 and 323 µS/cm respectively. The EC levels increase in dry periods (see Appendix A). A saline interception project a Jandra Station, 70 km north-east of Louth, is a large scale groundwater pumping project that intercepts deep-channel saline inflows entering the Darling River (Western CMA, 2010). Total phosphorus and turbidity levels were consistently poor. Of particular significance was the increasing trend in flow-adjusted turbidity levels identified in data from the site at Bourke, suggesting that this township may be significantly affecting water quality. There has also be an increase in agricultural activities, including cotton farming (DEWHA, 2009). Analysis of historical water quality conditions in this region has shown that general water quality declines in ‘dry years’ (defined as the 10th percentile in river flows corresponding to the water quality record) and improves in ‘wet years’ (defined as the 90th percentile in river flows corresponding to the water quality record) (see Appendix A). The table below summaries the trajectories for each water quality parameter during wet and dry extremes based on this historical analysis. It also describes the some potential consequences for the regional water quality dependent values. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 42 Literature Review Table 5-5 Consequences of wet and dry extremes for water quality in the Barwon Darling Region based on analysis of historical data (see Appendix A) Environmental values (High) Water Supply values (Mod) Recreational Values (Mod) Water Quality Trajectory -fish, macroinvertebrates -wetlands -irrigation -stock and domestic -primary contact -secondary contact -aesthetic values Wet Extreme Risks (Med) ↓Algal count ↓pH ↓Salinity ↑Turbidity ↑Total phosphorus -Temperature Extremely high turbidity levels will reduce primary productivity levels, resulting in less food resource for aquatic organisms. Extremely high turbidity levels may increase drinking water treatment costs. Extremely high turbidity levels make water undesirable and pose human health risks from associated pathogens. Dry Extreme Risks (High) ↑Algal count ↑pH ↑Salinity ↓Turbidity ↓Total phosphorus ↑↓Dissolved oxygen -Temperature Algal blooms and decaying algal blooms lead to oxygen draw down, with potentially lethal effects on aquatic organisms. Increasing salinity levels may go beyond the tolerance levels for some species. Algal toxins and algal biomass may cause water to be unsuitable for stock and domestic drinking water, and also clog infrastructure for irrigation. Increasing salinity levels also make water unsuitable. The human health, odour and visual impacts from algal blooms in the river will impact on primary, secondary and aesthetic values. Climate Scenario 5.4.2. 5.4.2.1. Border Rivers Overview The Border Rivers region transcends southern Queensland and north-eastern New South Wales. It represents 4 % of the total area of the MDB (CSIRO, 2008b). This region consists of the headwater streams, Macintyre Brook and Dumaresq River, that join the Macintyre River and later becomes the Barwon River. The dominant land use is broad-acre grazing on the tablelands and cropping (i.e. irrigated cotton crops) on the slopes and plains (CSIRO, 2008b). The recent climate (1997-2006) has been similar to the long-term average climate in the Border Rivers Region (CSIRO, 2008a). Currently 34 % of surface water availability is diverted for use, which has reduced the reliability of supply in the region and downstream. Groundwater development near the Dumaresq River is expected to be unsustainable, reducing groundwater levels and streamflow in the future (CSIRO, 2008a). Climate change is expected to reduce surface water availability by 10 %, however surface water use is predicted to decline by 2 % (CSIRO, 2008a). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 43 Literature Review 5.4.2.2. Values The Border River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in moderate condition. Native fish were abundant and most of the predicted native species occurred throughout the region. The intrusion of alien species was moderate (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in moderate condition with the lowland and slopes zones in better condition than the upland and montane zones. The communities at most sites were depleted and lacked many disturbance-sensitive families. Ecosystem health: Overall ecosystem health in the Border Rivers is ‘moderate’ (Davies et al., 2008). Nationally important wetlands: The floodplain between Goondiwindi and Mungindi contain the large anabranches and billabongs Morella Watercourse, Boobera Lagoon, Pungbougal Lagoon. These areas are considered to be one of the most important Aboriginal places in eastern Australia (CSIRO, 2008a). During floods, these areas provide large amounts of organic carbon to the river ecosystem downstream to support ecosystem function. Water Supply Irrigation: This region uses approximately 4.4% of the surface water diverted for irrigation and 2 % of the groundwater resource in the MDB. There are four major instream storages, Coolmunda, Glenlyon, Pindara and Rangers Valley Dams, that enable irrigated agriculture on the plains. Stock and domestic: Household consumption comprises approximately 1% of the total water consumption in the Border River region, and is typically groundwater. 5.4.2.3. Threats The water quality and flows in the Border Rivers is under threat from (BRGCMA, 2007): Overclearing and overgrazing of native vegetation causing erosion and increasing turbidity; Excessive use of herbicides, pesticides and fertilisers increasing nutrients and contaminants in waterways; Weed infestations (instream and riparian) change organic matter sources and lower dissolved oxygen; SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 44 Literature Review Draining of wetlands; and Reduced stream flow. 5.4.2.4. Water quality summary Water quality in the Border Rivers region is generally good, but is influenced by land use and regulated river flows. Land use and agricultural practices have contributed to elevated nutrient, pesticide, and sediment levels, and reduced river flows (McGloin, 2001). Water quality in the catchment is classified as fair to poor for total phosphorus and turbidity. These issues, along with reduced river flows, have led to algal blooms in the upper catchment (BRGCMA, 2007). The Border Rivers have low salinity levels and no significant temporal trends were detected. The Barwon, Macintyre and Dumaresq Rivers did not have any salinity problems, and all sites along these rivers, except the Macintyre River at Holdfast, had medians that were in the low salinity level category (0-280μS/cm). The Macintyre River at Holdfast had a medium salinity level (280800μS/cm) (McGloin, 2001). Conversely, total phosphorus and turbidity levels gradually increase along the basin. Increases in these levels are related to the changes in land use from grazing to cropping. The Macintyre River at Holdfast had the highest turbidity median (20 NTU) in the sub-catchment. No significant temporal trends were found for either of these variables, indicating that water quality is not improving (DEWHA, 2009). Monitoring of pesticides has shown a general decline in both the pesticide concentrations and number of samples detected, particularly for Endosulfan and Atrazine (BRGCMA, 2007). Analysis of historical water quality conditions in this region has shown that general water quality declines in ‘dry years’ (defined as the 10th percentile in river flows corresponding to the water quality record) and improves in ‘wet years’ (defined as the 90th percentile in river flows corresponding to the water quality record) (see Appendix A). The table below summaries the trajectories for each water quality parameter during wet and dry extremes based on this historical analysis. It also describes the some potential consequences for the regional water quality dependent values. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 45 Literature Review 5.4.3. 5.4.3.1. Campaspe Overview The Campaspe River Region is in Northern Victoria, covering approximately 4,000 km2 or 0.4 % of the MDB (CSIRO, 2008c). The Campaspe River extends for 150 km from the northern slopes of the Great Dividing Range near Woodend to the River Murray at Echuca. The Campaspe River and its tributary Coliban River are the largest rivers in the Campaspe Basin, but other significant tributaries include Axe, McIvor, Mt Pleasant, Forest, Wild Duck and Pipers Creeks. The catchment is mainly cleared with only 13% of the original forest vegetation remaining (Lorimer and Schoknecht, 1987). The catchment is agriculturally diverse, including dryland agriculture in the southern part of the catchment and irrigation crops, dairy farms and horticulture in the northern catchment. Dryland farming in the south produces cereal crops, beef cattle, lambs and wool, and some potatoes. Dairy farms are concentrated in the irrigated areas in the northern part of the catchment (NCCMA, 2005). Reservoirs and weirs for potable supply and irrigation has substantially reduced flows throughout the catchment and reversed seasonal flow patterns in the lower reaches. Regulation throughout the Campaspe River catchment diverts approximately 50% of mean annual discharge for irrigation, stock and domestic use (SKM, 2006a). The recent climate (1997-2006) has reduced surface water availability by 54 %, and reduced diversions by 26 % (CSIRO, 2008a). Climate change is expected to reduce surface water availability by 16 % and reduce surface water use by 5 % (CSIRO, 2008a). 5.4.3.2. Values The Campaspe River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in extremely poor condition. The community had lost most of its native species richness, and alien species contributed most of the biomass and abundance (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition, with all zones in poor to very poor condition. The communities at most sites were depleted and lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Campaspe Region is ‘very poor’ (Davies et al., 2008). Water Supply SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 46 Literature Review Irrigation: This region uses approximately 0.2 % of the surface water diverted for irrigation and 1.7 % of the groundwater resource in the MDB. Campaspe Weir, near Elmore, diverts flows to the Campaspe and Rochester Irrigation Districts and has a substantial effect on flow in the lower Campaspe River. There is also a Siphon near Rochester that diverts flow for InterValley transfers via the Western Waranga Channel. Lake Eppalock captures most of the flow from the upper part of the catchment during winter and spring and substantially reduces flow in the entire lower half of the Campaspe River (SKM, 2006a). Stock and domestic: The Upper Coliban, Lauriston and Malmsbury Reservoirs are on the Coliban River, and supply potable water to Bendigo and other towns in the region. Lake Eppalock supplements Bendigo’s water supply and services irrigation demand downstream. 5.4.3.3. Threats The water quality and flows in the Campaspe Region is under threat from (NCCMA, 2005): High salinity and saline stratified pools; Sand slugs in the Coliban River; Over-utilisation of water resources; High nutrients and turbidity from land-uses; Regional development (i.e. sustainable water management, land-use change). 5.4.3.4. Water quality summary High salinity, low dissolved oxygen and high nutrients are the three major water quality issues in the Campaspe River. Salinity and dissolved oxygen issues are most pronounced in pools within the Campaspe River downstream of the Campaspe Siphon and immediately downstream of Axe Creek (McGuckin, 1990). The tributaries, Axe Creek and Mt Pleasant Creek, are highly eroded and have elevated dryland salinity (SKM, 2006a). High flows from Lake Eppalock dilute inputs from these tributaries in the Campaspe River during the irrigation season, but at other times the tributaries are likely to adversely affect water quality in the main channel. Saline groundwater intrusions increase salinity in the lower reach and also cause the water in the pools to stratify under low flow conditions. Salinity levels slowly increase in the river from 1000 µS/cm to 3000 µS/cm during prolonged flows less than 100 ML/d (McGuckin, 1990). Typically, the pools are well mixed at flows above 200 ML/d and they experience problems when flows drop below 100 ML/d (SKM, 2006b). The lower water layer of pools can have salinities up to 14,000 µS/cm and experience prolonged anoxic conditions during these low flows. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 47 Literature Review Another dissolved oxygen issue centres around ‘blackwater events’. Blackwater is caused by high loads of leaf litter and other organic matter being entrained into the water column through heavy rainfall events. This effect causes sudden deoxygenation of the water column and can result in catastrophic ecological effects. An example of this occurring was when heavy localised rainfall in January 2001 flushed deoxygenated water from Mt Pleasant Creek and Forest Creek into the Campaspe River, causing a large fish kill between Runnymeade and the Campaspe Weir (McGuckin, 2001). High nutrient levels are considered a major threat to river health throughout the region, and discharge from the Campaspe River has a noticeable effect on nutrient levels in the River Murray (Cottingham et al., 1995). The major sources are wastewater treatment plant effluent, urban stormwater run-off, leaky septic tanks, diffuse runoff from agricultural land and soil erosion (SKM, 2006a). High nutrient levels can cause excessive growth of aquatic plants and algae. Algal bloom have been reported in Lake Eppalock, Malmsbury Reservoir and Campaspe Weir (Cottingham et al., 1995). MONITORING SITE: 406202 Campaspe R @ Rochester This site is located at Rochester, downstream of the Campaspe Siphon 5.4.4. 5.4.4.1. Condamine-Balonne Overview The Condamine-Balonne Region is in southern Queensland and extends about 100 km to the southwest into New South Wales. It covers an area of 136,500 km2 or 13% of the MDB (CSIRO 2008). The river changes name along its course. The Condamine River rises on the western side of the Great Dividing Range in the north-eastern Basin, flows north-west then west to Surat, where it becomes the Balonne River and flows south-westerly, breaking into distributary channels, the largest of these becoming the Culgoa River (Davies et al., 2008). The river terminates either to the Barwon River via the Culgoa and Bokhara rivers, or the Narran Lakes via braided streams on the Lower Balonne Floodplain (Davies et al., 2008). Land use in the Condamine-Balonne Region is dominated by dryland grazing and pasture. Other land uses include the irrigated crops grain and cotton (CSIRO, 2008d). Native vegetation comprises 17% of the region. The recent climate (1997-2006) has been similar to the long-term average climate in the Border Rivers Region (CSIRO, 2008a). Climate change is expected to reduce surface water availability by 8 %, and decrease surface water use by 4 % (CSIRO, 2008a). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 48 Literature Review 5.4.4.2. Values The Condamine-Balonne regional values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in moderate condition. Native fish were abundant, but were only half the total biomass. The intrusion of alien species was widespread (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. The communities at most sites were impoverished and lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Condamine-Balonne river is ‘moderate’ (Davies et al., 2008). Ramsar-listed wetlands: The Ramsar-listed Narran Lake Nature Reserve, located in NSW, is part of a large terminal wetland of the Narran River (which receives water from the Balonne River). This wetland is known for large-scale waterbird breeding associated with flooding (CSIRO, 2008a). Parts of the Balonne River floodplain are also of national importance. Water Supply Irrigation: This region uses approximately 3 % of the surface water diverted for irrigation and 10 % of the groundwater resource in the MDB. Around half of the annual average flow in the region is diverted, mostly for irrigation. There are 36 weirs along the 1,200 km CondamineBalonne River, impounding up to 27% of the water. Groundwater extraction is also twice the recharge rate, which is used to irrigate crops. Stock and domestic: Groundwater bores supply stock and domestic needs in the CondamineBalonne region. Cooby dam, on a tributary of the Condamine River, also supplies drinking water to Toowoomba. 5.4.4.3. Threats The water quality and flows in the Condamine-Balonne Region is under threat from: Loss of riverbank vegetation; Overgrazing and stock access to the rivers; High turbidity and phosphorus levels Sewage treatment plant effluent and stormwater runoff; SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 49 Literature Review 5.4.4.4. Water quality summary Water quality in the Condamine-Balonne Region has been deteriorating in recent years. There has been increasing community concern over declining water quality, in particular, an increased number of algal blooms and the detection of pesticides in water storage sediment. Water quality in the catchment varies from largely complying with the ANZECC guidelines in the upper catchment, to exceeding many of the parameters in the middle and lower floodplains. The water quality of the Condamine-Balonne Region declines downstream, with increasing turbidity, salinity and phosphorus (TREC, 2010). TP concentrations are extremely high in the middle catchment. This is thought to be a result from a combination of factors, including high sediment concentrations in the water and point discharges, such as treated sewerage, septic and animal husbandry effluent discharges (DEWHA, 2009). The Condamine-Balonne Region has low salinity levels. The long-term median and 80th%ile electrical conductivity (EC) levels at New Angeldool on the Narran River are 114 and 180 µS/cm respectively. The EC levels decreased mildly to 114 and 147 µS/cm respectively during the recent dry period (2007-08 data) (MDBA, 2009). High levels of nitrates have been recorded in the groundwater, with concentrations in excess of 40 mg/L in the urban centres, where intensive animal industries and septic tank leakages are concentrated. This is of particular concern to the Clifton Shire Council, which is dependent on groundwater for its town water supply (TREC, 2010). MONITORING SITE: Site #422015 Culgoa R @ Brenda and #422012 Narran R @ New Angeldool The Condamine-Culgoa Rivers basin is located in the Murray-Darling drainage division. Set inland, the topography is primarily flat with wide alluvial floodplains. There are slow flowing and meandering, with long periods of low or zero flows during which the streams can become a series of waterholes (DEWHA, 2009). The Balonne River break into distributary channels, the largest of these becoming the Culgoa River (Davies et al., 2008). The river terminates either to the Barwon River via the Culgoa and Bokhara rivers, or the Narran Lakes via braided streams on the Lower Balonne Floodplain. 5.4.5. 5.4.5.1. Goulburn-Broken Overview The Goulburn-Broken region occupies just 2% of the Murray-Darling Basin (16,800 km2), but provides 11% of the Basin’s stream flow (MDBC, 2008). The Goulburn River is the largest Victorian tributary to the River Murray. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 50 Literature Review The Broken River is a major tributary of the Goulburn River. A distributary channel, Broken Creek, leaves Broken River downstream of Benalla and joins the River Murray downstream of Barmah Forest (Cottingham et al., 2001). This naturally ephemeral creek, now continuously flows due to overflows from irrigation, stock and domestic water allocations from the Broken River (Cottingham et al., 2001). The predominant land use in the catchment is dryland cereal cropping and grazing (CSIRO, 2008e). A large proportion of the catchment is irrigated for pastures and hay and orchard production. Reservoirs for potable supply and irrigation has substantially reduced flows throughout the catchment and reversed seasonal flow patterns in the lower reaches. Lake Eildon is the major onstream storage on the Goulburn River. Water is harvested in winter and spring, and released for irrigation supply from November to May. This causes a seasonal reversal in the flow regime in the Goulburn River between Lake Eildon and Lake Nagambie (the major diversion point for irrigation water). Regulation throughout the Goulburn River catchment diverts approximately 50% of mean annual discharge for irrigation, stock and domestic use. The recent climate (1997-2006) has reduced surface water availability by 41%, and reduced diversions by 25 % (CSIRO, 2008a). Climate change is expected to reduce surface water availability by 14 % and reduce surface water use by 6 % (CSIRO, 2008a). 5.4.5.2. Values The Goulburn-Broken regional values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in extremely poor condition. Alien species dominate the biomass and total abundance. The community has lost most of its native fish species richness (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. The communities at most sites were depleted and lacked most of the disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Goulburn-Broken Region is ‘very poor’ (Davies et al., 2008). Nationally important wetlands: The lower Goulburn River and floodplain downstream of Loch Garry cover an area of 13,000 ha are listed as important billabongs, anabranches and swamps. The wetlands support a large number of flora and fauna, including native fish species, water SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 51 Literature Review birds and vegetation communities. The river also influences the Ramsar-listed BarmahMillewa Forest and Gunbower Forest wetlands during periods of high flow (CSIRO, 2008a). Water Supply Irrigation: This region generates 11% of the runoff within the MDB, and uses approximately 14 % of the surface water diverted for irrigation and 5.4 % of the groundwater resource in the MDB (CSIRO, 2008e). There are two instream storages, Lake Eildon (3334 GL) and Lake Nagambie (25.5 GL), and the latter is connected to an offstream storage, Waranga Basin (432 GL). Water from here is transferred to the Loddon or Campaspe valleys. Another offstream storage is Greens Lake (28 GL). Lake Nillahcootie is a major storages on the Broken River. Stock and domestic: The Goulburn River supplies drinking water to Melbourne through the Sugarloaf Pipeline, and also supplies many towns and cities in rural Victoria. Recreation Major storages, Lake Eildon and Lake Nagambie, are popular holiday destinations for water skiing, sailing, swimming and fishing. The lower Goulburn River floodplain is used extensively for recreation, including camping, canoeing, swimming and fishing. 5.4.5.3. Threats The water quality and flows in the Goulburn-Broken Region is under threat from: Bank erosion; Loss of instream habitat; Stock access; Water quality decline; Algal blooms; Degraded riparian vegetation. 5.4.5.4. Water quality summary Cold water pollution, high nutrients and turbidity and low dissolved oxygen are the major water quality issues in the Goulburn–Broken Catchment. Cold water releases from Lake Eildon strongly affect the biota downstream along the Goulburn River. Water temperatures are 5–7 °C lower than temperatures upstream of Lake Eildon in summer and 2–3 °C warmer in winter (SKM, 2005). While the catchment contributes approximately 33% of the River Murray’s water flow above the Murrumbidgee, it contributes nearly 60% of the turbidity (GBCMA, 2003). High nutrient loads SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 52 Literature Review also increase the risk of algal blooms and they occur frequently in the catchment. Major sources of turbidity and nutrients include irrigation drainage, sewage treatment plants, erosion, urban stormwater and intensive animal industries such as fish farms. Commonly used pesticides in intensive horticulture within the Shepparton Irrigation Region have been found in surface drainage water (GBCMA, 2003). Periodic algal blooms and high turbidity have occurred in the past in the Broken River. However, the water quality in Broken River is improving because of the decommissioning of Lake Mokoan. It is rated ‘good’ in the upper catchment with moderate nutrient concentrations and low salinity, but declines downstream due to septic tank leakage and stormwater from Benalla (Cottingham et al., 2001). The Goulburn River has low salinity levels. The long-term median and 80th percentile electrical conductivity (EC) at Goulburn Weir are 73 and 126 µS/cm respectively, which decreased to 59 and 101 µS/cm during the recent dry period (2007–08) (MDBA, 2009). Similarly, the Broken River has low EC, with modelled long-term average levels at Casey’s Weir of 130 µS/cm (1975–2000), which didn’t change in dry periods (SKM, 2009b). Prolific growth of the aquatic plant Azolla in the slow-flowing weir pools in Broken Creek has blanketed the surface of the water and cause the depletion of oxygen in the water column. Low dissolved oxygen due to the Azolla and the stagnation of flows, is considered to be the most likely cause of a large fish kill in 2002, where 179 Murray cod died between Rice’s and Kennedy’s Weirs (MDBC, 2005). MONITORING SITE: Site #405259 Goulburn R @ Goulburn Weir The Goulburn basin is located in the north central part of the State and has 17 monitoring sites representing roughly 100% of the basin. The majority of the catchment is used for agriculture with a small amount used for forestry. 5.4.6. 5.4.6.1. Gwydir Overview The Gwydir River Region is in north-eastern New South Wales. It rises on the western side of the Great Dividing range, near Armidale, and flows west (Davies et al., 2008). The river splits near the township of Moree, where it forms the Gwydir and Lower Gwydir Rivers. It covers 2 % of the MDB (CSIRO, 2008f). The predominant land use in the Gwydir region is dryland beef and sheep grazing (CSIRO, 2008f). Lucerne and pasture are grown on the floodplains in the upper Gwydir River and dryland crops are SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 53 Literature Review grown on the western plains (CSIRO, 2008f). Major agricultural industries are cotton, beef cattle, pecan-nutes, olives, wheat, wool and cereal crops. Native vegetation comprises 15% of the region. The recent climate (1997-2006) has been similar to the long-term average climate in the Gwydir River Region (CSIRO, 2008f). Climate change is expected to reduce surface water availability by 10 %, and reduce surface water diversions by 8 % (CSIRO, 2008a). The Gwydir River is highly regulated by the Copeton Dam and river flows are also affected by major water extractions. 5.4.6.2. Values The Gwydir River regional values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in poor condition. The majority of predicted native fish were present, but were only a third of the total biomass. The fish community had lost most of its species richness and was dominated by alien fish (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. The communities at most sites were impoverished and lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Gwydir River Region is ‘poor’ (Davies et al., 2008). Ramsar-listed wetlands: The Gwydir Wetlands cover an area of about 100,000 ha on the lower floodplain of the Gwydir River downstream of Moree. Four privately owned portions of these wetlands have received Ramsar-listing. They contain large expanses of Coolibah woodland, Water couch and Marsh Club-rush vegetation communities and the wetlands provide habitat for waterbirds listed under international treaties (CSIRO, 2008f). Water Supply Irrigation: This region uses approximately 3.5 % of the surface water diverted for irrigation and 2.8 % of the groundwater resource in the MDB. A high proportion (41%) of the surface water available in the Gwydir River is diverted for use. Groundwater use is 12 % of the average total water use. Nearly 90 % of the water used for irrigation is from the river (CSIRO, 2008f). Stock and domestic: Moree’s town water supply is from the Sub Artesian Bore. Small private diversions from the Gwydir River provide for stock and domestic needs. Recreation Hot mineral baths are a popular tourist attraction. These baths are from groundwater bores in the Great Artesian Basin. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 54 Literature Review 5.4.6.3. Threats The water quality and flows in the Gwydir Region is under threat from (BRGCMA, 2007): flow diversion; uncontrolled stock access and grazing of wetland vegetation; overclearing of native vegetation and further decline in native vegetation; weed invasion including the prolific aquatic weed, water hyacinth (Eichhornia crassipes); inappropriate and excessive use of herbicides, pesticides and fertilisers, which affects water quality; increased incidence of fires and inappropriate fire management. 5.4.6.4. Water quality summary There are a number of water quality issues in the Gwydir region. Diffuse sources of pollution associated with soil and streambank erosion increase turbidity, particularly in the lowland reaches of the catchment (BRGCMA, 2007). Excessive use of herbicides, pesticides and fertilisers is also recognised as a major threat to water quality. This has caused a change in water chemistry which favours algal growth and also growth of weed species instream and along the banks of waterways and wetlands. The mid‐catchment tributaries, Horton River and Warialda, Myall and Tycannah Creeks, have high salt concentrations (BRGCMA, 2007). High levels of turbidity are associated with stream bank and streambed erosion most likely associated with removal of riparian vegetation, but also an unnatural flow regime associated with releases from Copeton Dam. Thermal pollution downstream of Copeton Dam is another issue that is affecting water quality within the Gwydir River system (Copeland et al., 2003). High phosphorus, nitrogen and pesticides in this agricultural catchment are linked to excessive use of herbicides, pesticides and fertilisers. It is also exacerbated by the removal of native vegetation (BRGCMA, 2007). The Gwydir River has moderate salinity levels. The modelled long-term average electrical conductivity (EC) at Pallamallawa is 350 µS/cm, which was modelled to increase mildly to 376 µS/cm during dry periods (SKM, 2009b). Tributaries in the middle of the catchment deliver high salt loads (BRGCMA, 2007). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 55 Literature Review MONITORING SITE: Site # 418058 Mehi River @ Bronte Easting Northing Latitude Longitude 682738 6739005 29.4651 148.8845 5.4.7. 5.4.7.1. Lachlan Overview The Lachlan River Region is in central-western NSW. This region is based around the Lachlan River, which terminates in diverging creeks and the Great Cumbung Swamp in the lower part of its catchment. The Lachlan River is the only terminal system in the MDB and represents 8% of the total area of the MDB (CSIRO, 2008g). The dominant land use in the catchment is sheep and beef cattle grazing, and irrigated cropping of cereal, pasture and hay, with some small areas of cotton, orchards, viticulture and horticulture. Native vegetation constitutes less than 20% of the region (CSIRO, 2008g). The recent climate (1997-2006) has been similar to the long-term average climate in the Lachlan River Region (CSIRO, 2008g). Climate change is expected to reduce surface water availability by 11 %, and reduce surface water diversions by 8 % (CSIRO, 2008g). The flows in the Lachlan River are erratic and can have periods of zero flow over a year (e.g. 1944/45). 5.4.7.2. Values The Lachlan River regional values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in extremely poor condition. Loss of species richness, low abundance of native species and intrusions by alien species were apparent (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. There was a substantial loss of expected families, and most sites lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Lachlan River Region is ‘Very Poor’ (Davies et al., 2008). Nationally significant wetlands: The Booligal Wetlands complex covers 500 ha in the lower Lachlan and is well known for providing critical habitat for waterbirds. The Great Cumbung SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 56 Literature Review Swamp covers 16,000 ha at the terminus of the Lachlan River and is adjacent to the Murrumbidgee River and Lowbidgee Wetlands. It is one of the most important waterbird breeding areas in eastern Australia, supporting a large number of waterbirds during periods of flooding. Water Supply Irrigation: This region uses approximately 3.5 % of the surface water diverted for irrigation and 14.1% of the groundwater resource in the MDB. A high proportion (63 %) of the surface water available in the Lachlan River is diverted for use. Wyangala Dam on the Lachlan River upstream of Cowra is the major water storage. Groundwater is extracted from alluvial aquifers in the western portion of the region to irrigate cotton crops (CSIRO, 2008g). Stock and domestic: Groundwater is extracted from alluvial aquifers in the western portion of the region for stock and domestic use (CSIRO, 2008g). Recreation Recreational Fishing, water skiing. 5.4.7.3. Threats The water quality and flows in the Lachlan Region is under threat from (LCMA, 2006): Highly variable flows; dryland salinity; declining surface‐water quality; declining health and abundance of native vegetation; degradation of riparian and wetland ecosystems. 5.4.7.4. Water quality summary The major surface water quality issues in the Lachlan Catchment are increasing salinity, high nutrient levels, increasing frequency of algal blooms, high turbidity, pesticides and thermal pollution (LCMA, 2006). Groundwater resources are over-allocated in some areas of the catchment with consequences for groundwater dependent ecosystems, beneficial users and groundwater quality. Thermal pollution in rivers of the Lachlan catchment refers to the release of cold water from storages that alter the normal river temperature and impacts on aquatic habitat. It has been SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 57 Literature Review recognised as having a significant effect on the conditions required for native fish breeding in the Lachlan Catchment. Unseasonal changes in water temperatures at critical times have been reported approximately 170 km downstream of Wyangala Dam hindering fish breeding activities (LCMA, 2006). The Lachlan River has elevated salinity levels. The long-term median and 80th%ile electrical conductivity (EC) levels at Forbes are 471 and 609 µS/cm respectively. The EC levels increased mildly during the recent dry period (2007-08) (MDBA, 2009). Electrical conductivity is high in the Boorowra River, with levels of over 1400 EC have already been recorded in town water supplies. The WHO guideline for drinking water quality is below 800 EC. High nutrient loads in the catchment are the result of erosion. Diffuse sources (i.e. erosion, farm runoff) contribute 95% of the nutrient loads, while estimated 3% comes from point sources (i.e. trade waste, urban stormwater and sewage) (LCMA, 2006). These high nutrient loads increase the incidence of algal blooms. Blue-green algae monitoring of rivers and storages in the Lachlan catchment in 2008-09 showed that algal blooms were greatest at Lake Cargelligo, with bloom conditions reported for more than 50% of the time. Bloom conditions were also reported at times at Lake Forbes and Wyangala Reservoir. MONITORING SITE: Site #412004 Lachlan River at Forbes Easting Northing Latitude Longitude 592199 6303639 33.40261 147.9915 5.4.8. 5.4.8.1. Loddon Overview The Loddon River Region is in northern Victoria and covers 1.2 % of the MDB. This region consists of the Loddon River, which river rises in the Great Dividing Range south of Daylesford and flows 310 km to the River Murray north of Kerang (NCCMA, 2005). The majority of the flow is derived from the high rainfall area in the upper catchment above Laanecoorie Reservoir. In the lower catchment, downstream of Serpentine, the Loddon River becomes a series of anatomising distributary streams flowing northwards across the Riverine Plain with a floodplain 21 km wide (LREFSP, 2002). Barr Creek is the final tributary to enter the Loddon River. It drains an irrigation catchment and is considered to be one of the saltiest inland waterways in Victoria. A pump station located along the lower reaches of Barr Creek diverts water to the storage basin of Lake Tutchewop to manage flows and salinity levels in the Lower Loddon River and River Murray (NCCMA, 2005). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 58 Literature Review The predominant land use in the region is dryland agriculture, primarily cereal cropping and grazing. An extensive area is irrigated for cereal production and pasture for dairying, where the water supply is supported by inter-valley transfers from the Campaspe and Goulburn Rivers (Davies et al., 2008). Native vegetation covers only 11% of the region (CSIRO, 2008h). Reservoirs and weirs for potable supply and irrigation has substantially reduced flows throughout the catchment and reversed seasonal flow patterns in the lower reaches. Regulation throughout the Loddon catchment diverts approximately 32 % of mean annual discharge for irrigation, stock and domestic use (CSIRO, 2008h). The recent climate (1997-2006) has reduced surface water availability by 50 %, and reduced diversions by 27 % (CSIRO, 2008h). Climate change is expected to reduce surface water availability by 18 % and reduce surface water use by 6 %. 5.4.8.2. Values The Loddon River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in extremely poor condition. The fish community has losses in native species, low abundance of native fish and intrusion of alien species (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. The communities at most sites were impoverished and lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Loddon Region is ‘very poor’ (Davies et al., 2008). Ramsar-listed wetlands: The Kerang Wetlands, which spans the boundary of the Loddon and Murray regions, is listed as Ramar site of international significance. The lower Loddon River downstream of Kerang Weir provides important aquatic habitat for native fish species. Water Supply Irrigation: This region uses approximately 0.8 % of the surface water diverted for irrigation and 1.7 % of the groundwater resource in the MDB. Instream storages in the upper catchment include Cairn Curran and Tullaroop Dams and Laanecoorie Reservoir. Irrigation in the Pyramid Hill and Boort Irrigation areas are also supported by inter-valley transfers from the Campaspe, Murray and Goulburn Rivers via the Waranga Western Channel. Instream weirs (Serpentine, Loddon, Boags and Kerang) provide hydraulic heads for diversions. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 59 Literature Review Stock and domestic: The major reservoirs provide water supply to towns in the region, such as Tullaroop to Maryborough. Water supply at Kerang is supplemented with diversions from the Loddon River at Kerang. 5.4.8.3. Threats The water quality and flows in the Loddon Region is under threat from: Cease to flow in the river between Loddon Weir and Kerang Weir; Dryland salinity; Blackwater events; Colonisation of the river channel by riparian vegetation; Over-utilisation of water resources; Soil health (i.e. acid sulphate soils, soil erosion, soil structure decline); Water resources (i.e. water quality and river health decline, flooding due to changed land management, flow regulation, poor drainage, groundwater management); Regional development (i.e. sustainable water management, land-use change). 5.4.8.4. Water quality summary The water quality of the Loddon River decreases downstream due to high turbidity and nutrients and low in dissolved oxygen. The Loddon River is among the most turbid streams in Victoria with an average turbidity of 57 NTU (LREFSP 2002), almost twice the State Environment Protection Policy (Waters of Victoria) guideline of 30 NTU for Murray and Western Plains. Total nitrogen (TN) and total phosphorus (TP) levels are also elevated in the Loddon River compared to the SEPP (2003) guidelines. The Loddon River has elevated salinity levels. The modelled salinity at Laanecoorie Reservoir during the period from 1975 to 2000 was 1049 µS/cm (1975-2000), which increased to 1278 µS/cm during dry periods (1995-2000) (SKM 2009). Barr Creek has historically been the largest point source of salt to the River Murray. However, the amount of salt (and other pollutants) discharged to the River Murray is now partially controlled by the Lake Tutchewop diversion/evaporation scheme located at the downstream end of Barr Creek. Water quality declines significantly during cease to flow periods in the lower Loddon River. Isolated pools generally have low dissolved oxygen (DO), warm temperatures and high turbidity. Blackwater events have been reported in the Loddon River between Loddon Weir and Kerang Weir, particularly around the Twelve Mile Creek Offtake (SKM 2008). Continuous DO and SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 60 Literature Review temperature monitoring since April 2007, has shown that DO levels in isolated pools in the Loddon River declines to anoxic levels during the night and becomes super-saturated during the day. Algal blooms of varying severity occur annually in the Kerang Weir. MONITORING SITE: Site # Loddon River at Kerang 5.4.9. 5.4.9.1. Macquarie-Castlereagh Overview The Macquarie-Castlereagh Region is in central-west NSW and covers 6.9 % of the MDB (CSIRO, 2008i). This region contains the Macquarie, Castlereagh and Bogan Rivers. The Macquarie River is one of the main inland rivers in NSW. This system is a network of tributaries, anabranches and distributary streams that are of considerable importance for water resources, both for consumptive users and the environment. The three rivers travel generally northwest and end at the Macquarie Mashes (Macquarie River) or along the Barwon-Darling River (Castlereagh and Bogan Rivers). The predominant land use in the region is dryland pasture for livestock grazing. There are also areas irrigated for cotton and pasture production. Native vegetation covers 21.3% of the region. The recent climate (1997-2006) has been similar to the long-term average climate in the Macquarie-Castlereagh Region (CSIRO, 2008i). Climate change is expected to reduce surface water availability by 8 %, and reduce surface water diversions by 4 %(CSIRO, 2008i). 5.4.9.2. Values The Macquarie-Castlereagh River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in very poor condition. There were low abundance of native fish and alien species dominate the biomass and abundance (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. The communities at most sites had sparse fauna and lacked most disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Macquarie-Castlereagh Region is ‘very poor’ (Davies et al., 2008). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 61 Literature Review Ramsar-listed wetlands: The Macquarie Marshes are located at the end of the region. These wetlands are one of the largest and most important in the MDB. The Marshes are a series of braided channels and swamps that receive winter-spring floods from the Macquarie River, which maintains an inland reed swamp and open floodplain woodland wetland. Water Supply Irrigation: Surface water diversions in the region account for less than 4 % of the surface water diverted for irrigation and groundwater use is 10.9 % of the MDB. Instream storages include Burrendong Dam, Windamere Dam and Ben Chifley Dam. Eighty percent of the irrigation water is sourced from surface water diversions (CSIRO, 2008i). Stock and domestic: The major reservoirs provide water supply to towns in the region, such as Bathurst (Ben Chiefly), Mid-Western Region (Windamere Dam) and the Macquarie Valley (Burrendong Dam). The Macquarie River is used for stock, watering of parks, ovals, school grounds, gardens, industry, human consumption and recreation (Jenkins, 1998). Recreation Fishing, canoeing and boating around the Macquarie Marshes. 5.4.9.3. Threats The water quality and flows in the Macquarie–Castlereagh Region is under threat from: Dryland salinity. Declining surface water quality. Clearing of native riparian vegetation has resulted in widespread instability and erosion of the riverbanks. This also contributes to the accumulation of silt and sand in the river. Decreased flows at times of low flow and drought, with a reduction in the size of waterholes. Increased incidence of algal blooms, and nutrient inputs. Point and diffuse source pollution from urban and rural lands. This includes herbicides, nutrients, insecticides, fertilisers, stormwater run-off, septic systems and stock access to streams, and microbial contamination from sewerage treatment works. Rising watertables, dryland salinity and increased surface water salinity and turbidity. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 62 Literature Review 5.4.9.4. Water quality summary The major water quality issues in the Macquarie-Castlereagh Region are increasing trends in the levels of salinity, turbidity, nutrients, pesticides, thermal pollution and faecal coliforms (Jenkins, 1998). The Macquarie River has elevated salinity levels. The long-term median and 80th percentile electrical conductivity (EC) levels at Carinda are 564 and 666 µS/cm respectively, which decreased to 384 and 622 µS/cm respectively during the recent dry period (2007/08)(MDBA, 2009). Similarly, the Castlereagh River has elevated salinity levels with long-term median and 80th percentile EC levels at Gungalman Bridge of 413 and 764 µS/cm, which decreased over the recent dry period (2007/08) (MDBA, 2009). Levels of salinity rise and fall as water is released from Burrendong Dam (Jenkins, 1998). The level of salinity in the lower Macquarie River is influenced by high salt loads entering from the Talbragar River. Elevated turbidity levels in the downstream reaches of the Macquarie River are partially natural in their origin due to the highly weathered and ancient soils of the Western Plains. However, land clearing, cultivation, over grazing, roads and urban development have added significantly to turbidity levels (Jenkins, 1998). Nutrients enter the Macquarie-Castlereagh Rivers from diffuse farm runoff, sewerage treatment plant effluent, industrial discharges, septic tank leakage and stock access. The natural geology, particularly basalt, is also a major source of phosphorus (Jenkins, 1998). Algal blooms have occurred in Burrendong Dam and in the Macquarie River downstream as far as Warren weir. Burrendong Dam, during the summer months, becomes thermally stratified which increases the likelihood of algal blooms. There is also an impact on the river's aquatic ecosystem downstream by the release of hypoxic, cold and nutrient enriched water from the dam. This release of coldwater is suspected to affect the temperature of the Macquarie River as far down as Warren (Jenkins, 1998). The main pesticide detected in the Macquarie River is endosulfan, which is present during the spray season in areas downstream of irrigated agriculture (Jenkins, 1998). The faecal bacteria count is also rated fair to poor around urban centres, and makes the water unsuitable for primary contact. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 63 Literature Review MONITORING SITE: Site #420020 Castlereagh River @ Gungalman Bridge; Site #421012 Macquarie River @ Carinda; Site # 421023 Bogan River @ Gongolgon The Key Sites Water Quality Monitoring Program conducted by the Department of Land and Water Conservation since 1992, aims to provide information on long term trends in river water quality. It assesses water quality in three areas: Total Phosphorus, Electrical Conductivity and Turbidity. Easting Northing Latitude Longitude 420020 595967 6646430 30.31011 147.9981 421012 554695 6632902 30.43472 147.5697 421023 490503 6642599 30.34845 146.9012 5.4.10. Moonie 5.4.10.1. Overview The Moonie River Region is located mainly within south-western Queensland. It covers 1.4 % of the MDB (CSIRO, 2008j). The river flows in a south-west into NSW to the west of Mungindi and then into the Barwon River. The catchment contains no major towns and is undeveloped rural land. The dominant land use within the region is dryland pasture for livestock grazing. There is a small amount of irrigated cotton crops. Native vegetation comprises only 14.2 % of the region (CSIRO, 2008j). The Moonie River is ephemeral and the flow regime is dominated by extended periods of no flow. During these frequent and occasionally prolonged periods without flow the persistence of waterholes becomes of critical importance (CSIRO, 2008j). The recent climate (1997-2006) has been similar to the long-term average climate in the Moonie Region (CSIRO, 2008j). Climate change is expected to reduce surface water availability by 12 %, and reduce surface water diversions by 6 % (CSIRO, 2008j). 5.4.10.2. Values The Moonie River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in moderate condition. Native fish were abundant and most of the predicted native species occurred throughout the region. The intrusion of alien species was moderate (Davies et al., 2008). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 64 Literature Review Macroinvertebrates: The macroinvertebrate community was in moderate condition with the lowland and slopes zones in better condition than the upland and montane zones. The communities at most sites were depleted and lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Moonie River is ‘moderate-good’ (Davies et al., 2008). Wetlands: There are floodplain wetlands along the Moonie River and the Thallon waterholes have been identified as significant for waterbirds in the MDB (CSIRO, 2008j). Water Supply Irrigation: Surface water diversions in the region account for less than 0.2 % of the surface water diverted for irrigation and groundwater use is 0.1% of the MDB (excluding the confined aquifers of the Great Artesian Basin that provide around 70 percent of the groundwater used in the region).The Moonie River is unregulated and surface water diversions are small. However, almost all irrigation in the region depends on surface water (CSIRO, 2008j). There is one water storage facility on the river, Thallon Weir. Stock and domestic: Some water is taken from the sedimentary deposits that overly the Great Artesian Basin for stock and domestic purposes. 5.4.10.3. Threats The water quality and flows in the Moonie Region is under threat from: Uncontrolled stock grazing Road crossings Sedimentation Dryland salinity, soil acidity 5.4.10.4. Water quality summary The Moonie River is ephemeral and the flow regime is dominated by extended periods of no flow. During these frequent and occasionally prolonged periods without flow the persistence of waterholes of good quality becomes of critical importance to aquatic life. Generally waters of the Moonie River have high and variable turbidity, and increasing salinity and phosphorus with distance downstream. Excessive growth of algae is a major problem throughout streams in the north-western part of the catchment. Algal growth has resulted from nutrient SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 65 Literature Review enrichment from agricultural runoff, erosion of soils naturally high in phosphorus, septic tank effluent and low turbidity waters (Davies et al., 2008). The Moonie River has low salinity levels. The long-term median and 80th percentile electrical conductivity (EC) levels at Fenton are 125 and 155 µS/cm. The EC levels increased mildly during dry periods to 138 and 155 µS/cm respectively (MDBA, 2009). Some water is taken from the overlying alluvial system for stock and domestic purposes. It is generally high in salinity (>20,000 mg/L Total Dissolved Solids (TDS)) though local perched systems in the lower reaches can be fresher (<350 mg/L TDS). Pressures on water quality are a major community concern in the Moonie catchment, with the removal of native vegetation, cropping and cattle grazing, and runoff from settlements and treated sewage discharges, each implicated in declines in water quality standards in the catchment. Analysis of historical water quality conditions in this region has shown that general water quality declines in ‘dry years’ (defined as the 50th percentile in river flows corresponding to the water quality record due to lack of data) and improves in ‘wet years’ (defined as the 50th percentile in river flows corresponding to the water quality record) (see Appendix A). The table below summaries the trajectories for each water quality parameter during wet and dry extremes based on this historical analysis. It also describes the some potential consequences for the regional water quality dependent values. Table 5-6 Consequences of wet and dry extremes for water quality in the Moonie River Region based on analysis of historical data (see Appendix A) Climate Scenario Water Quality Trajectory * Environmental values (High) Water Supply values (low) -fish, macroinvertebrates -irrigation Wet Extreme Risks (Low) -pH ↓Salinity ↓Turbidity ↓Total nitrogen - Dissolved oxygen -Temperature Water quality generally improves when the river is flowing. Water quality generally improves when the river is flowing. Dry Extreme Risks (High) ↑ pH ↑Salinity ↑Turbidity ↑Total nitrogen ↓ Dissolved oxygen -Temperature ↑Algal growth As an ephemeral system, good water quality in refuge pools is essential for the survival of aquatic organisms. Dry extremes present a risk from low DO, high turbidity and increasing salinity. Algal 1 growth is also an issue . Water is used for irrigation and stock watering. High turbidity and increasing salinity levels present a risk to water supply values. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 66 Literature Review *This assessment is based on limited data; (1) based on literature review – not data. 5.4.11. River Murray 5.4.11.1. Overview The River Murray is Australia’s largest river. It forms the border between NSW and Victoria as it flows northwest, before turning south into South Australia. This region extends the full length of the River Murray and includes the lower Darling River, representing 19.5% of the MDB (CSIRO, 2008k). The River Murray is strongly affected by inflows from the Barwon-Darling, Murrumbidgee, Ovens, Goulburn-Broken, Campaspe and Loddon River regions (CSIRO, 2008k). The River Murray terminates at Lake Alexandrina and The Coorong before emptying through the Murray Mouth into the Southern Ocean. The predominant land use in the region is dryland pasture for livestock grazing and dryland cropping. Other land uses include horticulture, hay production and rice growing. Forestry plantations are common in the upper Murray catchment. Native vegetation covers 22 % of the region (CSIRO, 2008k). Regulation throughout the River Murray region diverts approximately 56 % of mean annual discharge for irrigation, stock and domestic use, which is extremely high. The recent climate (1997-2006) has reduced surface water availability by 30 %, and reduced diversions by 13 % (CSIRO, 2008k). Climate change is expected to reduce surface water availability by 14 %, reduce surface water use by 4 % and reduce end of system flows by 24% (CSIRO, 2008k). 5.4.11.2. Values The River Murray regional values that are dependent on good water quality are summarised below. Environmental Fish: The upper Murray fish community was in extremely poor condition, while the central and lower fish community was in poor condition. Alien species dominate the biomass and total abundance. The community has lost most of its native fish species richness (Davies et al., 2008). Macroinvertebrates: The upper Murray macroinvertebrate community was in moderate condition, while the central and lower macroinvertebrate community was in poor condition. The communities at most sites were depleted and lacked most of the disturbance-sensitive families. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 67 Literature Review Ecosystem health: The river ecosystem health in the upper River Murray is ‘very poor’, while the central and lower Murray was in ‘poor’ condition (Davies et al., 2008). Ramsar-listed wetlands: The River Murray Region contains several large and important wetlands, including the Living Murray Icon sites. These include the Barmah-Millewa Forest, Gunbower-Koondrook-Perricoota Forest, Lower Darling River and Anabranch Lakes, Hattah Lakes, Chowilla Floodplain and Lindsay-Wallpolla Islands, and the lower Lakes, Coorong and the Murray Mouth. The wetlands support a large number of flora and fauna, including native fish species, water birds and vegetation communities. Water Supply Irrigation: This region uses over 36 % of the surface water diverted for irrigation and urban use and 14 % of the groundwater resource in the MDB (CSIRO, 2008k). Major storages used for irrigation and water supply are Dartmouth Dam, Lake Hume, Yarrawonga Weir, Lake Victoria, Torrumbarry Weir, and Weirs 1-10 (Loch). Stock and domestic: The River Murray supplies drinking water many towns and cities in rural Victoria, NSW and SA. It is a key drinking water source for the city of Adelaide. Recreation Major storages are popular holiday destinations for water skiing, sailing, swimming and fishing. The River Murray floodplain is used extensively for recreation, including camping, canoeing, swimming and fishing. 5.4.11.3. Threats The water quality and flows in the Murray Region is under threat from: Overgrazing and stock access to floodplain; Discharges from wastewater treatment plants; Urban stormwater; Irrigation drainage, land clearing and poor land management; Degradation of the riparian zone; Altered flow regime and over-allocated resources; Rising salinity; SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 68 Literature Review Nutrients and suspended sediments are poor and worsening towards the Murray Mouth; Algal blooms. 5.4.11.4. Water quality summary The major water quality threats in the River Murray region are salinity, algal blooms and cold water pollution. The River Murray has increasing salinity levels along its length. The long-term median and 80th percentile electrical conductivity (EC) levels at Murray Bridge are 555 and 811 EC respectively. During the recent dry period the median EC decreased mildly to 623 EC, but the 80th percentile increased to 832 EC for 2007/08 (MDBA, 2009). Many significant algal blooms have occurred throughout the history of the river. The first ever algal bloom recorded in Australia was discovered in Lake Alexandria in 1878. The two most common types of blue-green algal species recorded in the River Murray are Anabaena sp. and Microcystis sp. Blue-green algal blooms have been increasing in frequency and duration in the River Murray between Lake Hume to Wentworth during the recent drought. Blue green algal blooms prevent water-based recreational activities, such as fishing and swimming, and can disrupt drinking water treatment processes. Cold water pollution is an issue downstream of Dartmouth Dam. This is caused by the release of cold water from storages that alter the normal river temperature and impacts on aquatic habitat downstream. It has been recognised as having a significant effect on the conditions required for native fish breeding in the upper Murray region. This is caused by storage releases, is a key issue for riverine ecology, particularly fish species. Blackwater events, associated with the flooding of the Barmah-Millewa Forests are also known to adversely affect water quality in the River Murray (Howitt et al., 2007). MONITORING SITE: Site # 409016 Murray River @ D/S Hume Weir (Heywoods) Easting Northing Latitude Longitude 502163 6005038 36.0993 147.024 SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 69 Literature Review 5.4.12. Murrumbidgee 5.4.12.1. Overview The Murrumbidgee Region is located in southern NSW. It covers 8.2% of the MDB (CSIRO, 2008m). The Murrumbidgee River is a major river draining most of southern NSW and all of the Australian Capital Territory (ACT). It travels west 900 km from the Snowy Mountains, through the ACT, to its confluence with the River Murray. The predominant land use is dryland pasture for livestock grazing and dryland cropping. There are also irrigated areas for cereals, pasture and hay production, and citrus and grapes are grown in the central area of the irrigation district. Native vegetation covers 17% of the region (CSIRO, 2008m). Regulation throughout the Murrumbidgee catchment diverts approximately 53 % of mean annual discharge for irrigation, stock and domestic use, which is an extremely high level of water resource development (CSIRO, 2008m). The recent climate (1997-2006) has reduced surface water availability by 30 %, and reduced diversions by 18 % (CSIRO, 2008m). Climate change is expected to be less severe than the recent climate, and is expected to reduce surface water availability by 9 % and reduce surface water use by 2 %. 5.4.12.2. Values The Murrumbidgee River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in extremely poor condition. The fish community has losses in native species, low abundance of native fish and intrusion of alien species (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. The communities at most sites had low diversity and lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Murrumbidgee Region is ‘very poor’ (Davies et al., 2008). Nationally important wetlands: the Mid Murrumbidgee Wetlands and Lowbidgee Floodplain are important wetlands supporting native vegetation communities of River Red Gum forests and woodlands. Water Supply Irrigation: This region uses approximately 22 % of the surface water diverted for irrigation and 24 % of the groundwater resource in the MDB. Instream storages in the catchment include SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 70 Literature Review Blowering Reservoir and Lake Burrinjuck. Blowering Reservoir is used to supply irrigation water in the region. Stock and domestic: The Cotter Dam, on the Cotter River, which is a tributary of the Murrumbidgee River, supplies drinking water to Canberra. Recreation Major storages are used for boating and water-sports. 5.4.12.3. Threats The water quality and flows in the Murrumbidgee Region is under threat from: erosion and riverbank instability; blue-green algal blooms; salinity from dryland areas and from rising groundwater; thermal pollution; sewage entering creeks and rivers; nutrient runoff from farms; uncontrolled stock access; and pesticides and other chemicals entering creeks and rivers. 5.4.12.4. Water quality summary The major water quality issues in the Murrumbidgee are high turbidity and moderate nutrient levels (Gell and Little, 2007;DEWHA, 2009). The major storages release good quality water upstream, but degraded inflows from the mid-catchment tributaries and catchment land use degrades water quality downstream. Water with low levels of salinity and moderate levels of turbidity are generally released from Burrinjuck Dam. The major source of sediments, and thus phosphorus loads, in the upper and midMurrumbidgee comes from erosion of stream banks, stream beds and gullies. The lower Murrumbidgee Catchment acts as a sink for nutrients. In the major storages, Blowering Dam generally has good water quality, as a result of a nearpristine catchment. Nutrient levels, algal counts and turbidity levels are generally very low. Burrinjuck storage has variable nutrients, with some releases containing moderate levels of nitrogen and phosphorus. There are frequent blue-green algal blooms during spring and summer. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 71 Literature Review The Murrumbidgee River has low salinity levels. The long-term median and 80th percentile electrical conductivity (EC) levels at Balranald Weir are 275 and 415 µS/cm respectively. EC levels have decreased marginally during the recent dry period (MDBA, 2009). Analysis of historical water quality conditions in this region has shown that general water quality declines in ‘wet years’ due to catchment runoff (defined as the 90th percentile in river flows corresponding to the water quality record) and improves in ‘dry years’ (defined as the 10th percentile in river flows corresponding to the water quality record) (see Appendix A). The table below summaries the trajectories for each water quality parameter during wet and dry extremes based on this historical analysis. It also describes the some potential consequences for the regional water quality dependent values. Table 5-7 Consequences of wet and dry extremes for water quality in the Murrumbidgee Region based on analysis of historical data (see Appendix A) Climate Scenario Water Quality Trajectory Environmental values (High) Water Supply values (High) Recreational Values (Mod) -fish, macroinvertebrates -wetlands -irrigation -stock and domestic -primary contact -secondary contact -aesthetic values Wet Extreme Risks (Med) -pH ↑Salinity -Turbidity ↑Total phosphorus ↑Total nitrogen ↓Dissolved oxygen -Temperature An increase in nutrient loads from catchment runoff may lead to nuisance plant growth and algal blooms, with lethal effects for aquatic organisms. Increasing salinity levels may go beyond the tolerance levels for some species. Algal toxins and algal biomass may cause water to be unsuitable for stock and domestic drinking water, and also clog infrastructure for irrigation. Increasing salinity levels also make water unsuitable. The human health, odour and visual impacts from algal blooms in the river will impact on primary, secondary and aesthetic values. Dry Extreme Risks (Med) -pH ↓Salinity - Turbidity ↓Total phosphorus ↓Total nitrogen ↓Dissolved oxygen -Temperature Low dissolved oxygen levels during warm weather may stress aquatic organisms. High turbidity levels may present water treatment concerns. High turbidity levels may present human health concerns from associated pathogens. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 72 Literature Review 5.4.13. Namoi 5.4.13.1. Overview The Namoi River region is located in north-eastern NSW. It covers 3.8% of the MDB (CSIRO, 2008n). This region contains the Namoi, Manilla and Peel Rivers. The Namoi River rises in the Great Dividing Range and flows west to join the Barwon River. The predominant land use is cattle and sheep grazing on dryland pastures. Wheat, cotton and other broadacre crops are grown on the floodplains. Native vegetation covers 25.6% of the region (CSIRO, 2008n). Approximately 37 % of mean annual discharge is diverted for irrigation, stock and domestic use (CSIRO, 2008n). The recent climate (1997-2006) has been similar to the long-term average climate in the Namoi Region (CSIRO, 2008n). Climate change is expected to reduce surface water availability by 5 % and reduce surface water use by 1 %. 5.4.13.2. Values The Namoi River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in poor condition. Most predicted native species were found, but alien fish were abundant (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. The communities at most sites had low diversity and lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Namoi Region is ‘poor’ (Davies et al., 2008). Nationally important wetlands: Lake Goran, adjacent to the Liverpool Plains, is the terminus of an internal drainage basin that does not connect to the Namoi River. Other billabongs and wetlands are important environmental assets for providing the river with dissolved organic matter. Water Supply Irrigation: This region uses approximately 2.6 % of the surface water diverted for irrigation in the MDB. It has one of the highest levels of groundwater extraction in the MDB, using 15.2 % of the groundwater resource (CSIRO, 2008n). Instream storages in the catchment include SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 73 Literature Review Keepit Dam (Namoi), Split Rock Dam (Manilla) and Chaffey Dam (Peel), which store water for irrigation supply. Stock and domestic: Weirs on the Namoi provide urban, stock and domestic supplies (Davies et al., 2008). 5.4.13.3. Threats The water quality and flows in the Namoi Region is under threat from: degradation of the riparian zone from weeds and overgrazing; bank and riverbed instability, and aggradation of sediments; poor water quality, mainly because of high total phosphorus, turbidity and salinity levels and localised incidence of pesticide contamination; dryland salinity; sedimentation from overgrazing, erosion and bank slumping; increasing frequency of algal blooms; and excessive groundwater usage, particularly in the drier months. 5.4.13.4. Water quality summary Major water quality issues in the Namoi Region include salinity, turbidity, nutrient enrichment and contamination with agricultural chemicals. Water quality in the Namoi River is variable and often does not meet ANZECC (2000) guidelines(NCMA, 2007). The Namoi River has elevated salinity levels. The long-term median and 80th percentile electrical conductivity (EC) levels at Goangra are 403 and 556 µS/cm respectively. The EC levels decreased to 284 and 397 µS/cm during the recent dry period (2007/08) (MDBA, 2009). Salinity is widely recognised as a land and water management problem across the region. A number of major tributaries of the Namoi have inherently high salinity levels, including Goonoo Goonoo, Mooki, Upper Manilla, Quirindi and Werris Creeks (NCMA, 2007) Total phosphorus and total nitrogen concentrations are high across the catchment due to sewage treatment plant effluent, septic tank leakage, farm effluent, runoff from agricultural land and urban stormwater (NCMA, 2007). Turbidity levels increase downstream and are highest in the mid catchment in areas associated with cropping. Blue-green algal outbreaks are also common during the summer months, and are attributed to the high levels of instream phosphorus (NCMA, 2007) SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 74 Literature Review Pesticides (including herbicides, pesticides and defoliants) in surface waters are a high profile issue in the catchment. Pesticides are detected regularly in areas that are intensively cropped, although levels have declined markedly in the last decade (NCMA, 2007). In general, water quality of the Namoi river system is moderate to poor, with high levels of nutrients, areas contaminated by agricultural chemicals as well as on-going salinity problems. MONITORING SITE: Site #419026 Namoi River @ Goangra Easting Northing Latitude Longitude 633614 6664570 30.14288 148.3873 5.4.14. Ovens 5.4.14.1. Overview The Ovens River region is in north-eastern Victoria and covers 0.7 % of the MDB (CSIRO, 2008o). This region contains the Ovens River and its major tributary the King River. The Ovens River rises near Mount Buffalo in the Victorian Alps, and flows northwest to Wangaratta then north to join the River Murray at Lake Mulwala. The King River joins the Ovens River at Wangaratta. The predominant land use in the region is dryland pasture using for beef and sheep grazing. Over half of the region is covered with native vegetation, particularly in the highlands (CSIRO, 2008o). This region generates around 6 % of the runoff within the MDB. The Ovens River is unregulated upstream of Myrtleford and is only partly regulated due to the presence of storages on its tributaries. The recent climate (1997-2006) has reduced surface water availability by 27 % (CSIRO, 2008o). Climate change is predicted to be less severe than the recent past, and is expected to reduce surface water availability by 13 %. 5.4.14.2. Values The Ovens River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in poor condition. Only 59% of the predicted native fish species were found and the community had lost much of its species richness. Alien fish were abundant (Davies et al., 2008). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 75 Literature Review Macroinvertebrates: The macroinvertebrate community was in poor condition. The communities at most sites were missing expected families and lacked most disturbancesensitive families. Ecosystem health: Overall river ecosystem health in the Ovens Region is ‘Poor’ (Davies et al., 2008). Heritage River: The Ovens River is a Victorian Heritage River and is recognised as an environmental asset of national importance due to its largely natural flow regime, diverse aquatic habitats, range of threatened fish species and intact riparian zone. Water Supply Irrigation: This region uses approximately 0.2 % of the surface water diverted for irrigation and 0.4 % of the groundwater resource in the MDB. Instream storages in the upper catchment include Lake Buffalo (Buffalo) and Lake William Hovell (King). Stock and domestic: Diversions from the Ovens and King Rivers are used as the town water supply for Wangaratta and other stock and domestic needs. Tourism The Ovens River region is used for swimming, fishing, camping and bushwalking. 5.4.14.3. Threats The water quality and flows in the Ovens Region is under threat from: Uncontrolled stock access; Sand slugs from erosion; Waste water treatment plant effluent and septic tank leakage; Urban runoff; Cold water releases from storages. 5.4.14.4. Water quality summary The water quality in the Ovens River is in very good to excellent condition, but some tributaries throughout the upper Ovens River have high turbidity levels and high nutrient concentrations due to urban and agricultural practices (SKM, 2006c). The water quality in the Ovens River reflects the primarily forested catchment, particularly in the uplands. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 76 Literature Review The Ovens River has very low salinity levels. The long-term median and 80th percentile electrical conductivity (EC) levels at Peechelba-East are 69 µS/cm and 101 µS/cm respectively. These EC levels decreased during the recent dry period, with median and 80th percentile EC levels at 52 and 70 µS/cm respectively for 2007/08 (MDBA, 2009). The turbidity levels are low and have been below 10 NTU on most sampling occasions over the last five years (SKM, 2006c). The Victorian Alpine Bushfires in 2002-2003 burned a large portion of the Ovens Region, which was followed by a large rain event that caused a slug of organic matter rich bushfire runoff to degrade the water quality in the Buckland and Ovens River. Nutrient levels are locally elevated near urban centres due to septic tank leakage and waste water treatment plant effluent (SKM, 2006c). High nutrient levels have also been associated with the bushfire runoff. The main flow-related water quality issue in the Ovens River is low dissolved oxygen during periods of sustained low flow. The duration of low flow periods has increased over the summer months under drought conditions and increased demand on water resources during the summer season (Cottingham et al., 2008). Analysis of historical water quality conditions in this region has shown that general water quality declines in ‘dry years’ (defined as the 10th percentile in river flows corresponding to the water quality record) and improves in ‘wet years’ (defined as the 90th percentile in river flows corresponding to the water quality record) (see Appendix A). The table below summaries the trajectories for each water quality parameter during wet and dry extremes based on this historical analysis. It also describes the some potential consequences for the regional water quality dependent values. Table 5-8 Consequences of wet and dry extremes for water quality in the Ovens River Region based on analysis of historical data (see Appendix A) Climate Scenario Wet Extreme Risks (Low) Water Quality Trajectory -pH ↓Salinity ↑Turbidity ↑Total phosphorus ↑Total nitrogen ↑ Dissolved oxygen -Temperature Environmental values (High) Water Supply values (Mod) Recreational Values (Mod) -fish, macroinvertebrates -heritage river -irrigation -stock and domestic -primary contact -secondary contact -aesthetic values Changes in water quality condition are expected to be minor, with the exception of the major rainfall events post bushfires, when the threat is high. Changes in water quality condition are expected to be minor, with the exception of the major rainfall events post bushfires, when the threat is high. Changes in water quality condition are expected to be minor, with the exception of the major rainfall events post bushfires, when the threat is high. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 77 Literature Review Dry Extreme Risks (Low) - pH ↑Salinity ↓Turbidity ↓Total phosphorus ↓Total nitrogen ↓ Dissolved oxygen -Temperature Changes in water quality condition are expected to be minor. Changes in water quality condition are expected to be minor. Changes in water quality condition are expected to be minor. 5.4.15. Paroo 5.4.15.1. Overview The Paroo River region is located in south-western Queensland in the far north-west corner of the MDB. It covers 3.4 % of the MDB (CSIRO, 2008p). It is an episodic stream and there is no flow for around 35 % of the time (Davies et al., 2008). The Paroo River dissipates into a large deflation area called the Paroo Overflow. This area contains significant wetlands that store the water that supports a diverse ecosystem of international signficance. The river water rarely connects to the Darling River. The predominant land use in the region is broadacre livestock grazing for beef and wool production (CSIRO, 2008p). The Paroo River is the only unregulated rive r with the MDB. There are no major dams and very little irrigation in the Paroo Region. The recent climate (1997-2006) has been similar to the longterm historical climate (CSIRO, 2008p). Climate change is expected to reduce surface water availability by 3 %. Climate change is also likely to affect the ecology of the wetlands in the region. 5.4.15.2. Values The Paroo River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in moderate condition. Native fish were abundant, but only 58 % of the predicted native fish species were found. (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in moderate condition. Most sites retained their expected families, but were lacking some disturbance-sensitive families due to drought. Ecosystem health: Overall river ecosystem health in the Paroo Region is ‘Good’ (Davies et al., 2008). SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 78 Literature Review Ramsar-listed Wetlands: The Currawinya Lakes, including Lake Numulla and Lake Wyara, are considered the most important wetlands in Australia, supporting up to 250,000 waterbirds. The Paroo Overflow Lakes are also largely dependent on flooding from the Paroo River. This includes the Paroo River Waterholes, the Paroo Distributary Channels and the Paroo Overflow Lakes. The Paroo River Wetlands – a recently listed Ramsar site – are a combination of the Nocoleche Nature Reserve and two of the many lakes in the Paroo Overflow. The lakes are on the floodplain south of Wanaaring in New South Wales where floods typically dissipate without reaching the Darling River. Water Supply Irrigation: There is little diversion from the Paroo and no instream storages. Groundwater use is low and does not impact on streamflow. Stock and domestic: Most of the region has access to the Great Artesian Groundwater Basin. Tourism The Paroo-Darling National Park is used for camping. 5.4.15.3. Threats The water quality and flows in the Paroo Region is under threat from: carp, goldfish and plague minnow is a critical issue; Drought and drying of waterholes.; land degradation due to over‐grazing; clearing of marginal lands, declining quality of river systems. 5.4.15.4. Water quality summary The Paroo River is ephemeral and the flow regime is dominated by extended periods of no flow. The persistence of waterholes with good water quality becomes of critical importance to sustaining water-dependent life during the frequent and occasionally prolonged periods without flow. The major water quality issues for the waterholes in the Paroo River region are low dissolved oxygen, high temperatures, high pH (alkaline) and moderate nutrients (Bailey, 2001). Nutrients accumulate and any disturbance to the ecology could result in algal blooms. Turbidity is naturally high as a result of low plant cover and the intense nature of rainfall. There is a long travel SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 79 Literature Review time for flood waters, which could lead to evaporative losses and the assimilation of nutrients (Bailey, 2001). The Paroo River has low salinity levels. The long-term median and 80th percentile electrical conductivity (EC) levels at Caiwarro are 74 and 119 µS/cm respectively. EC levels have increased during the recent dry period to give a median and 80th percentile of 81 and 172 µS/cm respectively for 2007/08 (MDBA 2009b). Analysis of historical water quality conditions in this region has shown that general water quality declines in ‘dry years’ (defined as the 50th percentile in river flows corresponding to the water quality record due to lack of data) and improves in ‘wet years’ (defined as the 50th percentile in river flows corresponding to the water quality record) (see Appendix A). The table below summaries the trajectories for each water quality parameter during wet and dry extremes based on this historical analysis. It also describes the some potential consequences for the regional water quality dependent values. Table 5-9 Consequences of wet and dry extremes for water quality in the Paroo River Region based on analysis of historical data (see Appendix A) Climate Scenario Water Quality Trajectory* Wet Extreme Risks (Mod) ↓pH - Salinity ↑Turbidity -Total phosphorus -Total nitrogen 1 ↓Dissolved oxygen ↑Temperature Dry Extreme Risks (Mod) ↑pH -Salinity ↑Turbidity -Total phosphorus -Total nitrogen 1 ↓ Dissolved oxygen 1 ↑Temperature Environmental values (High) Water Supply values (low) Recreational Values (low) -fish, macroinvertebrates -heritage river -irrigation -stock and domestic -primary contact -secondary contact -aesthetic values Water quality generally improves when the river is flowing, however turbidity levels are extremely high. There is very little diversion from the river. High turbidity levels may limit water use. Water quality generally improves when the river is flowing, however, turbidity levels are extremely high. As an ephemeral There is very little system, good water diversion from the quality in refuge river. High turbidity pools is essential levels may limit for the survival of water use. Algal aquatic organisms. blooms may Dry extremes present a health hazard for stock. present a risk from low DO, high turbidity and high temperatures. Algal growth is also an 1 issue . *This assessment is based on limited data; (1) based on literature review – not data Campers may find water undesirable due to high turbidity and potential toxicity from algal blooms. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 80 Literature Review 5.4.16. Warrego 5.4.16.1. Overview The Warrego River region is located in south-western Queensland and northern NSW. It covers 7 % of the MDB (CSIRO, 2008q). The Warrego River flows south to meet the Darling River downstream of Bourke, but water only reaches the Darling during floods. It is an episodic stream and there is no flow for around 50 % of the time (Davies et al., 2008). The predominant land use in the region is dryland pasture, including beef cattle and sheep grazing, and small areas of cotton farming and horticulture. Native vegetation, in the form of National Parks and State Forests comprise 10 % of the region. Rainfall and runoff are highly variable between years and stream flow mostly occurs as large infrequent floods (CSIRO, 2008q). There are no major dams and only a small irrigated area in the Warrego Region. The recent climate (1997-2006) has been similar to the long-term historical climate (CSIRO, 2008q). Climate change is expected to reduce surface water availability by 6 %. 5.4.16.2. Values The Warrego River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in poor condition. Only half of the predicted native species were recorded. Native fish were dominant in abundance, but alien species dominated the biomass (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in poor condition. Most sites had few expected and disturbance sensitive families. Ecosystem health: Overall river ecosystem health in the Warrego Region is ‘poor’ (Davies et al., 2008). Important wetlands: Key ecological assets are the Warrego River Waterholes and Yantabulla Swamp. The Warrego River Waterholes are a string of large, permanent and intermittent waterholes and billabongs that provide habitat for fish, invertebrates, turtles and birds as well as vegetation communities. Yantabulla Swamp support native vegetation communities and provides breeding habitat for waterbirds under international treaties (CSIRO, 2008q). Water Supply Irrigation: There is little diversion from the Warrego River and no in-stream storages. Groundwater use is low and does not impact on streamflow. At Cunnamulla, the Allan SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 81 Literature Review Tannock Weir may divert water for local cotton irrigation and town water supply (CSIRO, 2008q). Stock and domestic: Weirs are used for stock and domestic supply along the Warrego River. Tourism Fishing, swimming, canoeing and camping occurs along the Warrego River, particularly at a permanent waterhole at Bakers Bend. 5.4.16.3. Threats The water quality and flows in the Warrego Region is under threat from: Drought and drying of waterholes.; Land degradation due to over‐grazing; Clearing of marginal lands, and Carp, goldfish and plague minnow. 5.4.16.4. Water quality summary The Warrego River is ephemeral and the flow regime is dominated by extended periods of no flow (up to 50 % of the time). Harsh, variable and ephemeral conditions have lead to a highly specialised low diversity riverine ecology. During dry seasons, waterholes become enclosed ecosystems and refugia for aquatic organisms. The persistence of these waterholes with good water quality becomes of critical importance to sustaining water-dependent life during the prolonged periods without flow. The major water quality issues for the waterholes in the Warrego River region, similar to the Paroo Region, are low dissolved oxygen, high temperatures, high pH (alkaline) and moderate nutrients (Bailey, 2001). Nutrients accumulate and any disturbance to the ecology could result in algal blooms. Turbidity is naturally high as a result of low plant cover and the intense nature of rainfall. There is a long travel time for flood waters, which could lead to evaporative losses and the assimilation of nutrients (Bailey, 2001). The Warrego River has low salinity levels. The long-term 80th%ile electrical conductivity (EC) level at Barringun is 123 µS/cm. The EC levels increased marginally to 139 µS/cm during the recent dry period in 2007-08 (MDBA, 2009). MONITORING SITE: Site # 423004 Warrego River @ Barringun SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 82 Literature Review 5.4.17. Wimmera-Avoca 5.4.17.1. Overview The Wimmera-Avoca River Region is in north-western Victoria and covers 4.3 % of the MDB. The region is comprised of the Wimmera and Avoca Rivers. The rivers flow north from the Grampians National Park into terminal lakes. The Wimmera River terminates at the Ramsar-listed sites Lake Hindmarsh and Lake Albacutya, and the Avoca River flows into the Avoca Marshes and Lake Boga. The predominant land use in the region is dryland agriculture, primarily cereal cropping and grazing. An extensive area is irrigated for cereal production and pasture for dairying, which is supported by inter-valley transfers from the Glenelg River (CSIRO, 2008r). The Wimmera and Avoca Rivers are highly regulated. Regulation throughout the region diverts approximately 59 % of mean annual discharge for irrigation, stock and domestic use (CSIRO, 2008r). The recent climate (1997-2006) has reduced surface water availability and use by 50 %, (CSIRO, 2008h). Climate change is predicted to be less severe than the recent climate, and is expected to reduce surface water availability and use by 6 %. 5.4.17.2. Values The Wimmera-Avoca River values that are dependent on good water quality are summarised below. Environmental Fish: The fish community is in poor condition. The fish community has low abundance of native fish and intrusion of alien species (Davies et al., 2008). Macroinvertebrates: The macroinvertebrate community was in very poor condition. The communities at most sites were impoverished and lacked many disturbance-sensitive families. Ecosystem health: Overall river ecosystem health in the Wimmera-Avoca Region is ‘very poor’ (Davies et al., 2008). Ramsar-listed wetlands: Lake Hindmarsh and Lake Albacutya (Wimmera) and the Kerang Lakes and Lake Bael Bael are Ramsar-listed sites in the region. Water Supply Irrigation: This region uses approximately 1.0% of the surface water diverted for irrigation and 0.1 % of the groundwater resource in the MDB. There are seven major storages on tributaries of the Wimmera that supply irrigation water. There are no instream storages on the Avoca, SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 83 Literature Review apart from 12 low-level weirs that provide water supply during low flows. Farm dams support irrigation in the upper reaches(Davies et al., 2008). Stock and Domestic: Surface water diversions are primarily for stock and domestic use, but also for urban supply and limited irrigation. Groundwater is also used for these purposes (CSIRO, 2008r). 5.4.17.3. Threats The water quality and flows in the Wimmera-Avoca Region is under threat from: Dryland salinity; Colonisation of the river channel by riparian vegetation; Over‐utilisation of water resources; Flow cessation in parts of the Wimmera and Avoca rivers; Biodiversity decline; River bank erosion and fragility; and Algal blooms. 5.4.17.4. Water quality summary The primary water quality issue in the Wimmera-Avoca region is high salinity levels due to saline groundwater intrusion (SKM, 2002). The long-term median and 80th percentile electrical conductivity (EC) levels at Quambatook on the Avoca River is 4,200 and 8,200 µS/cm respectively (MDBA, 2009). Similarly, the Wimmera River has elevated EC with median and 80th percentile levels at Horsham Weir of 1,248 and 1,712 µS/cm respectively, decreasing to 705 and 731 respectively during the recent dry period (2007-08) (MDBA, 2009;SKM, 2009b). Significant increases in salinity can occur when flows drop below 10-20 ML/d (SKM, 2002). Under these conditions, saline pools form. These saline pools are characterised by a salt-stratified high density bottom layer that has low dissolved oxygen making it uninhabitable by fish and macroinvertebrates. Low dissolved oxygen is a problem in particularly the Wimmera River during low flow conditions (SKM, 2002). Nutrient and turbidity levels are high owing to agricultural land-use practices in the region. Long term water quality trends show increasing electrical conductivity, increasing total nitrogen, increasing turbidity and decreasing dissolved oxygen, and that all of the water quality variables were linked to recent prolonged drought conditions. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 84 Literature Review Analysis of historical water quality conditions in this region has shown that general water quality declines in ‘dry years’ (defined as the 10th percentile in river flows corresponding to the water quality record) and improves in ‘wet years’ (defined as the 10th percentile in river flows corresponding to the water quality record) (see Appendix A). The table below summaries the trajectories for each water quality parameter during wet and dry extremes based on this historical analysis. It also describes the some potential consequences for the regional water quality dependent values. Table 5-10 Consequences of wet and dry extremes for water quality in the Wimmera River Region based on analysis of historical data (see Appendix A) Climate Scenario Water Quality Trajectory * Environmental values (High) Water Supply values (High) -fish, macroinvertebrates -irrigation Wet Extreme Risks (Med) -pH ↓Salinity ↑Turbidity ↑Total nitrogen ↑Total phosphorus - Dissolved oxygen -Temperature High turbidity levels will reduce primary productivity levels, resulting in less food resource for aquatic organisms. Extremely high turbidity levels may increase drinking water treatment costs. Dry Extreme Risks (High) ↑ pH ↓Salinity ↓Turbidity ↑Total nitrogen ↑Total phosphorus ↓ Dissolved oxygen ↑Temperature Low dissolved oxygen and high water temperatures may have potentially lethal effects on aquatic organisms. Increasing salinity levels may go beyond the tolerance levels for some species in saline pools in the lower catchment. Algal toxins and algal biomass may cause water to be unsuitable for stock and domestic drinking water, and also clog infrastructure for irrigation. Increasing salinity levels also make water unsuitable. 5.5. Assets dependent on good water quality 5.5.1. Environmental The following listed wetlands have been listed as environmental assets in the MDB. Table 5-11 Key environmental assets. State Asset Name Qld Culgoa River Floodplain Qld / NSW Lower Balonne Floodplain Channel System NSW Narran Lakes Nature Reserve NSW Lower Murrumbidgee Floodplain NSW Mid Murrumbidgee Wetlands SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 85 Literature Review NSW Booligal Wetlands NSW Great Cumbung Swamp NSW Gwydir Wetlands NSW Macquarie Marshes Nature Reserve - North NSW Macquarie Marshes Nature Reserve - South NSW Goddard's Lease NSW Old Dromana (Big Leather) NSW Barmah-Milewa Forest NSW Fivebough-Tuckerbil Ramsar sites NSW Wilgara NSW Crinolyn NSW Lower Lachlan including Lake Brewster NSW Wyndella Vic Lower Goulburn Floodplains Vic Lake Albacutya Vic Kerang Wetlands Vic / SA Chowilla Floodplain including Lindsay and Wallpolla Islands SA Banrock Station Wetland complex SA Riverland 5.5.2. Drinking water There are 21 large, 31 medium and 129 small urban centres located in the Murray-Darling Basin – a total of 181 urban centres. These are located mainly in the South Eastern edges of the basin. In addition, many cities and rural localities source their water supply from the Basin, but are not located within the Basin. The most notable of these cities include Adelaide in South Australia, and Melbourne and Ballarat in Victoria. Table 5-8 lists some of the pipelines which supply urban centres outside of the Basin. Table 5-12 Pipelines which supply urban centres and rural localities outside of the Basin. State South 1 Australia Pipeline/pump name Off take point Urban centres supplied Morgan Pumps Murray River Hanson, Spalding, Helshaby, Port Augusta, Whyalla, Woomera, Iron Knob, Jamestown, Peterborough Swan Reach Pumps Murray River Barossa Valley, Lower North and Yorke Peninsula Mannum Pumps Murray River Torrens Valley and eastern foothills Adelaide via the metropolitan reticulation system through the Anstey Hill Water Filtration Plant; can also discharge into numerous reservoirs SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 86 Literature Review 2 Victoria Murray Bridge Pumps Murray River Adelaide via the Onkaparinga River channel and Mount Bold Reservoir, and Summit Storage Water Treatment Plant Tailem Bend Pumps Murray River Thirteen towns and a large agricultural area Wimmera-Mallee 3 pipeline Murray River @ Swan Hill Wimmera-Mallee reservoirs 7,000 rural customers and 36 towns Goldfields Superpipe Links the Waranga Western Channel near Colbinabbin, Lake Eppalock, Bendigo’s Sandhurst Reservoir and White Swan Reservoir Ballarat and Bendigo Sugarloaf Pipeline Goulburn River @ Yea Melbourne (1) http://www.sawater.com.au/SAWater/Education/OurWaterSystems/Pipelines.htm (2) http://www.ourwater.vic.gov.au/programs/water-grid (3) http://www.environment.gov.au/water/policy-programs/water-smart/projects/pubs/vic-wimmera-malleepipeline.pdf. Technically located within the MDB, the Wimmera catchment is rarely connected to the Murray River by flows. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 87 Literature Review 6. References Surface water references Astles, K. L., Winstanley, R. K., Harris, J. H. & Gehrke, P. C. (2003) Experimental study of the effects of cold water pollution on native fish. Final report for the Regulate Rivers and Fisheries Restoration Project. . (ed^(eds. NSW Fisheries Final Report Series No. 44. NSW Fisheries Research Institute, Cronulla. Bailey, V. (2001) Western stream water quality monitoring project. (ed^(eds. Department of Natural Resources, Queensland. Baker, A. (2003) Land use and water quality. Hydrological Processes, 17, 2499-2501. Bates, B. C., Kundzewicz, Z. W., Wu, S. & Palutikof, J. P. (2008) Climate Change and Water. (ed^(eds, pp. 210 pp. Technical Paper of the Intergovernmental Panel on Climate Change, IPCC Secretariat, Geneva. BOM (2010) Climate Change http://www.bom.gov.au/climate/change/. (ed^(eds. Bureau of Meteorology. Bond, N., Lake, P. S. & Arthington, A. H. (2008) The impacts of drought on freshwater ecosystems: an Australian perspective. Hydrobiologia, 3-16. Boys, C., Miles, N. & Rayner, T. (2009) Scoping options for the ecological assessment of cold water pollution mitigation downstream of Keepit Dam, Namoi River. (ed^(eds. Final report prepared for the Native Fish Strategy, Murray-Darling Basin Commission MDBA Publication 20/09. 52pp. ISBN 978-1-921257-82-7., Canberra, Australia. Brabec, E., Schulte, S. & Richards, P. L. (2002) Impervious Surfaces and Water Quality: A Review of Current Literature and Its Implications for Watershed Planning. Journal of Planning Literature, 16, 499-514. BRGCMA (2007) Border Rivers - Gwydir Catchment Action Plan. (ed^(eds. Border RiversGwydir Catchment Management Authority. Bunn, S. E., Davies, P. M. & Mosisch, T. D. (1999) Ecosystem measures of river health and their response to riparian and catchment degradation. Freshwater Biology, 41, 333-345. Byers, H. L., Cabrera, M. L., Matthews, M. K., Franklin, D. H., Andrae, J. G., Radcliffe, D. E., McCann, M. A., Kuykendall, H. A., Hoveland, C. S. & Calvert, V. H., II (2005) Phosphorus, Sediment, and Escherichia coli Loads in Unfenced Streams of the Georgia Piedmont, USA. J Environ Qual, 34, 2293-2300. Caruso, B. S. (2001) Regional river flow, water quality, aquatic ecological impacts and recovery from drought. Hydrological Sciences, 46, 677-699. Caruso, B. S. (2002) Temporal and spatial patterns of extreme low flows and effects on stream ecosystems in Otago, New Zealand. Journal of Hydrology, 257, 115-133. Chartres, C., Stauffacher, M., Walker, G. & Hatton, T. (2003) Is the River Murray water quality deteriorating? A Salinity Perspective. (ed^(eds. A publication of CSIRO Land and Water Australia. Copeland, C., Schooneveldt-Reid, E. & Neller, S. (2003) Fish Everywhere: An oral history of fish and their habitats in the Gwydir River. (ed^(eds. NSW fisheries. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 88 Literature Review Cottingham, P., Bennison, G., Dunn, R., Lidston, J. & Robinson, D. (1995) Algal bloom and nutrient status of Victorian inland waters. (ed^(eds. Report prepared for the Government of Victoria, Melbourne. Cottingham, P., Gawne, B., Gigney, H., Koehn, J., Roberts, J., Stewardson, M. & Vietz, G. (2008) Lower Ovens Environmental Flows Project: Environmental flow recommendations. (ed^(eds. Report prepared for the North Eastern Catchment Management Authority. Peter Cottingham & Associates and the Murray-Darling Freshwater Research Centre. Cottingham, P., Stewardson, M., Roberst, J., Metzeling, L., Humphries, P., Hillman, T. & Hannan, G. (2001) Report of the Broken River Scientific Panel on the enviornmental condition and flows of the Broken River and Broken Creek. (ed^(eds. Technical Report 10/2001; A report for the Department of Sustainability and Environment. CSIRO (2008a) Water Availability in the Barwon Darling. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008b) Water Availability in the Border Rivers. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008c) Water Availability in the Campaspe River. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008d) Water Availability in the Condamine-Balonne. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008e) Water Availability in the Goulburn-Broken. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008f) Water Availability in the Gwydir. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008g) Water Availability in the Lachlan. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008h) Water Availability in the Loddon-Avoca. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008i) Water Availability in the Macquarie-Castlereagh. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008j) Water Availability in the Moonie. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008k) Water Availability in the Murray. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008l) Water availability in the Murray-Darling Basin. . (ed^(eds, pp. 67pp. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project, CSIRO, Australia. CSIRO (2008m) Water Availability in the Murrumbidgee. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008n) Water Availability in the Namoi. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008o) Water Availability in the Ovens. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 89 Literature Review CSIRO (2008p) Water Availability in the Paroo. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008q) Water Availability in the Warrego. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2008r) Water Availability in the Wimmera. (ed^(eds. CSIRO Murray-Darling Basin Sustainable Yields Project - a report to the Australian Government. CSIRO (2010) State of the Climate. (ed^(eds. Bureau of Meteorology, Australian Government Davies, P., Harris, J. H., Hillman, T. & Walker, K. (2008) SRA Report 1: A report on the Ecological Health of Rivers in the Murray-Darling Basin, 2004-2007. (ed^(eds. Prepared by the Independent Sustainable Rivers Audit Group for the Murray-Darling basin Ministerial Council. DEWHA (2009) Australian Natural Resources Atlas, 2000-2002 National Land and Water Resources Audit: Water Resources - Quality http://www.anra.gov.au/topics/water/quality. (ed^(eds. Department of the Environment, Water, Heritage and the Arts. Dunlop, M. & Brown, P. R. (2008) Implications of climate change for Australia's national reserve system: a preliminary assesment. (ed^(eds. CSIRO Sustainable Ecosystems report to the Department of Climate Change and the Department of the Environment, Water, Heritage and the Arts, Canberra. GBCMA (2003) Goulburn Broken Regional Catchment Strategy. (ed^(eds. Goulburn Broken Catchment Management Authority. Gehrke, P. C., Gawne, B. & Cullen, P. (2003) What is the status of river health in the MurrayDarling basin? (ed^(eds. A publication of CSIRO Land and Water Australia. Gell, P. & Little, F. (2007) Water quality history of Murrumbidgee River Floodplain Wetlands. (ed^(eds. Land and Water Australia, Australian Government. Hargrave, C. W., Gary, K. P. & Rosaldo, S. K. (2009) Potential effects of elevated atmospheric carbon dioxide on benthic autotrophs and consumers in stream ecosystems: a test using experimental stream mesocosms Global Change Biology, 2779-2790. Howitt, J., Baldwin, D. S., Rees, G. S. & Williams, J. L. (2007) Modelling blackwater: predicting water quality during flooding of lowland river forests. Ecological Modelling, 203, 229242. Jenkins, C. (1998) Water Quality - Macquarie River. (ed^(eds. Water Quality - Draft information sheet for Macquarie 2100, Trangie, NSW. Jones, R., Whetton, P., Walsh, K. & Page, C. (2002) Future impacts of climate variability, climate change and land use change on water resources in the Murray Darling Basin: Overview and Draft Program of Research. (ed^(eds. CSIRO Atmospheric Research. LCMA (2006) Lachlan Action Plan 2006-2016. (ed^(eds. Lachlan Catchment Management Authority. Lintermans, M. (2007) Fishes of the Murray Darling Basin: An introductory guide. (ed^(eds. Murray Darling Basin Commission Publication No. 10/07, Canberra. Lorimer, M. S. & Schoknecht, N. R. (1987) A study of the land in the Campaspe River catchment. Land Protection Division. Department of Conservation, Forests and Lands, Victoria, Melbourne. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 90 Literature Review LREFSP (2002) Environmental flow determination of the Loddon River catchment. Part A - Issues Paper. (ed^(eds. A report prepared by the Loddon River Environmental Flows Scientific Panel for the North Central Catchment Management Authority and Department of Natural Resources and Environment, Huntly. McCarthy, B., Conalin, A., D'Santos, P. & Baldwin, D. S. (2006) Acididication, salinisation and fish kills at an inland wetland in south-eastern Australia following partial drying. Ecology Management Restoration, 7, 218 -223. McGloin, E. ( 2001) Water Quality and Management Options in the Border Rivers Catchment. (ed^(eds. Border River Catchment Management Association. McGuckin, J. (1990) Environmental considerations of salinity in the Campaspe River downstream of Lake Eppalock. (ed^(eds. Kaiela Fisheries Research Station - Department of Conservation, Forests and Lands Victoria, Shepparton. McGuckin, J. (2001) Fish kill in the Campaspe River at Elmore, January 2001. (ed^(eds, pp. 4. Streamline Research Pty Ltd. MDBA (2009) MDBC Basin Salinity Management; 2007-08 Annual Implementation Report. (ed^(eds. Murray Darling Basin Commission. MDBC (2005) MDBA Native fish strategy: Annual implementation report 2004-2005. . (ed^(eds. Murray-Darling Basin Commission, Canberra. MDBC (2008) Sustainable Rivers Audit. Murray-Darling Basin Rivers: Ecosystem Health Check, 2004-2007. (ed^(eds. Murray-Darling Basin Commission NCCMA (2005) North Central River Health Strategy. (ed^(eds. North Central Catchment Management Authority, Huntly. NCMA (2007) Namoi Catchment Action Plan. (ed^(eds. Namoi Catchment Management Authority. NLWR (2001) River condition in the Murray-Darling Basin 2001. (ed^(eds. National Land and Water Resources Audit 2000. Pittock, B. (2003) Climate change: an Austrlaian guide to science and impacts. (ed^(eds. Australian Greenhouse Office, Canberra. Poff, L. N., Allan, J. D., Bain, M. D., Karr, J. R., Prestegaard, K. L. & Richter, B. D. (1997) The natural flow regime, a paradigm for river conservation and restoration. Bioscience, 47, 769-784. Poff, N. L., Brinson, M. M. & Day, J. W. J. (2002) Aquatic ecosystems and global climate change. Potential impacts of inland freshwater and coastal wetland ecosystems in the United States. (ed^(eds. Report prepared for the Pew Center on Global Cliamte hcnage. Poff, N. L., Tokar, S. & Johnston, P. (1996) Stream hydrological and ecological response to climate change assessed with an artifical neural network. Limnology and Oceanography, 41, 857-863. Prosser, I. P., Moran, C. J., Lu, H., Olley, J., DeRose, R. C., Cannon, G., Croke, B., Hughes, A. O., Jakeman, T., Newham, L., Scott, A. & Weisse, M. (2003) Basin-wide mapping of sediment and nutrient exports in dryland regions of the Murray-Darling basin. (ed^(eds, pp. 38. CSIRO Land and Water, Canberra. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 91 Literature Review Prosser, I. P., Rutherfurd, I. D., Olley, J. M., Young, W. J., Wallbrink, P. J. & Moran, C. J. (2001) Large-scale patterns of erosion and sediment transport in river networks, with examples from Australia. Marine & Freshwater Research, 52, 81-99. Quinn, J. M., Cooper, A. B., Davies-Colley, R. J. & Williamson, R. B. (1997) Land use effects on habitat, water quality, periphyton, and benthic invertebrates in Waikato, New Zealand, hill-country streams. New Zealand Journal of Marine & Freshwater Research, 31, 579597. Richter, B. D., Baumgartner, J. V., Wigington, R. & Braun, D. P. (1997) How much water does a river need? Freshwater Biology, 37, 231-249. Rutherford, J. C., Marsh, N. A., Davies, P. M. & Bunn, S. E. (2004) Effects of patchy shade on stream water temperature: how quickly do small streams heat and cool? Marine & Freshwater Research, 55, 737-748. Sauer, T. J., Daniel, T. C., Moore, P. A., Jr., Coffey, K. P., Nichols, D. J. & West, C. P. (1999) Poultry Litter and Grazing Animal Waste Effects on Runoff Water Quality. J Environ Qual, 28, 860-865. SKM (2002) Stressed rivers project - Environmental flow study - Wimmera River system. (ed^(eds. A report prepared by Sinclair Knight Merz for the Wimmera CMA. SKM (2005) Temperature monitoring of dam releases in Victorian rivers 2002-2004. (ed^(eds. Department of Sustainability and Environment, Melbourne. SKM (2006a) Campaspe River environmental FLOWS assessment: issues paper final. (ed^(eds. Report prepared for the North Central CMA, Melbourne. SKM (2006b) Longitudinal survey of saline pools in the Lower Campaspe River. (ed^(eds. Sinclair Knight Merz. SKM (2006c) Upper Ovens River Environmental Flows Assessment: Issues Paper. (ed^(eds. A report prepared by Sinclair Knight Merz for the North East CMA. SKM (2009a) Implications of climate change for natural resource management in the MurrayDarling Basin: Part 1: A collation of recent research. (ed^(eds. A report prepared by Sinclair Knight Merz for the Murray-Darling Basin Authority, Canberra. SKM (2009b) Salinity Targets Review: Task IV - River Salinity Data Analysis. (ed^(eds. A report prepared by SKM for Murray-Darling Basin Authority. SOE (2009) Hydrological cycle with land use impacts, . (ed^(eds. http://soer.justice.tas.gov.au/2009/image/126/ilw/o-Waterlanduse-126-m.gif, State of the Environment, Tasmania Hobart. TREC (2010) The State of our Water Resources: Rivers, Wetlands and Floodplains. (ed^(eds. http://www.trec.org.au/SODR/Index/Water/water.html. Wallbrink, P. J. (2004) Quantifying the erosion processes and land-uses which dominate fine sediment supply to Moreton Bay, Southeast Queensland, Australia. Journal of Environmental Radioactivity, 76, 67-80. Walsh, C. J. (2000) Urban impacts on the ecology of receiving waters: a framework for assessment, conservation and restoration. Hydrobiologia, 431, 107-114. Walsh, C. J., Roy, A. H., Feminella, J. W., Cottingham, P. D., Groffman, P. M. & Morgan, R. P. (2005) The urban stream syndrome: current knowledge and the search for a cure. Journal of the North American Benthological Society, 24, 706-723. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 92 Literature Review Western CMA (2007) Western Catchment Action Plan 2006-2016. (ed^(eds. Western Catchment Management Authority, NSW Government. Western CMA (2010) The Barwon-Darling River: River Flows and Water Quality. (ed^(eds. Western Catchment Management Authority, NSW Government. Young, R. G. & Huryn, A. D. (1999) Effects of land use on stream metabolism and organic matter turnover. Ecological Applications, 9, 1359-1376. Groundwater References: Adelaide and Mount Lofty Ranges Natural Resource Management Board, (2007) Climate Change in the Adelaide and Mount Lofty Ranges Region. Allen, D., Mackie, D., Wei, M. (2004) Groundwater and climate change: a sensitivity analysis for the Grand Forks aquifer, southern British Columbia, Canada. Beare, S., Heaney, A. (2002) Climate change and water resources in the Murray Darling Basin, Australia. ABARE Conference Paper 02.11 Brouyere, S., Carabin, G., Dassargues, A. (2004) Climate change impacts on groundwater resources: modelled deficits in a chalky aquifer, Geer basin, Belgium. Connor, J., Doble, R., Elmahdi, A. (2008) Integrated systems evaluation of climate change and future adaptation strategies for the Lower River Murray, Australia. 2nd International Salinity Forum, Salinity, water and society-global issues, local action. CSIRO (2008). Water availability in the Murray-Darling Basin. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 67pp. DECC 2009. Salinity Audit – Upland catchments of the NSW MDB. Ficklin, D., Luedeling, Eike., Zhang, Minghua. (2010) Sensitivity of groundwater recharge under irrigated agriculture to changes in climate, CO 2 concentrations and canopy structure. Agricultural Water Management. Gleick, P. (2000) Water: The Potential Consequences of Climate Variability and Change for the Water Resources of the United States. Ivkovic, K.M., Watkins, K.L., Cresswell, R.G., & Bould, J. (2001). A groundwater quality assessment of the Upper Shepparton Formation Aquifers: Cobram Region, Victoria. Bureau of Rural Sciences, Canberra. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 93 Literature Review John, M., Pannell, D., and Kingwell, R., 2005. Climate Change and the Economics of Farm Management in the Face of Land Degradation: Dryland Salinity in Western Australia. Kuo-Chin, Hsu., Chung-Ho, Wang., Kuan-Chih, Chen., Chien-Tai, Chen., Kai-Wei, Ma. (2007) Climate-induced hydrological impacts on the groundwater system of the Pingtung Plain, Taiwan. Hydrogeology Journal, 15: 903 – 913. Moustadraf, J., Razack, M., Sinan, M. (2008) Evaluation of the impacts of climate changes on the coastal Chaouia aquifer, Morocco, using numerical modelling. Hydrogeology Journal (2009) 16: 1411-1426. Please, P.M., Watkins, K.L., Cresswell, R.G. and Bauld, J., (2000). A groundwater quality assessment of the alluvial aquifers in the Border Rivers Catchment (Qld/NSW). Bureau of Rural Sciences, Canberra. SKM (2009) Adaptation options for climate change impacts on groundwater resources. Prepared for the World Bank, February 2009. Timms, W., Acworth, I., Jankowski, J., & Lawson, S. (1999). Groundwater quality in a aquifer aquitard system subjected to large volume abstraction for irrigation in the Lower Murrumbidgee. In Murray-Darling Basin Groundwater Workshop .Integrated Perspectives., Griffith, pp. 131.136. Walker, G., Gilfedder., M and Williams., J. 1999. Effectiveness of current farming systems in the control of dryland salinity. Canberra: CSIRO Land and Water. Watkins, K.L. and Bauld, J. (1999) A groundwater quality assessment of the shallow aquifers of the Murray Region, NSW. Bureau of Rural Sciences, Canberra. Watkins, K.L., Ivkovic, K.M. and Bauld, J. (1999) A groundwater quality assessment of the Goulburn Catchment, Victoria: Nagambie-Mangalore. Bureau of Rural Sciences, Canberra. Watkins, K.L., Ivkovic, K.M. and Bauld, J. (1999). A groundwater quality assessment of the Goulburn Catchment, Victoria: Kyabram-Tongala. Bureau of Rural Sciences, Canberra. Woldeakmlak, S., Batelaan, O., Smedt, F. (2007) Effects of climate change on the groundwater system in the Grote-Nete catchment, Belgium. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 94 Literature Review a. Barwon-Darling MONITORING SITE: Site #425008 Darling River: Wilcannia (Main Channel) Easting Northing Latitude Longitude 725940 6505891 31.55986 143.3804 The site is located next to the township of Wilcannia, in flat, arid and sparsely vegetated countryside. The town garbage depot, caravan park and golf course are nearby, and slaughter yards are a short distance downstream. Dryland grazing is the dominant land use in the catchment. The site is sampled as part of MDBA's Menindee Lakes Water Quality Monitoring Program. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 95 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 96 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 97 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 98 Literature Review b. Border Rivers MONITORING SITE: Site #416001 Barwon River: Mungindi Easting Northing Latitude Longitude 693389 6793025 28.97611 148.9847 This site is located downstream of Mungindi, in flat, open countryside supporting scattered timber growth. Large-scale cotton irrigation occurs both upstream and downstream of Mungindi, and in areas of cattle grazing that are not under cotton. The site is sampled as part of DLWC's Statewide Key Sites Water Quality Trend Assessment Program (DEWHA, 2009). c. Moonie Region MONITORING SITE: Site #417204 Moonie R @ Fenton SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 99 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 100 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 101 Literature Review d. Murrumbidgee Region MONITORING SITE: Site #410130 Murrumbidgee at D/S Balranald Weir Easting Northing Latitude Longitude 728333 6161264 34.66528 143.4919 SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 102 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 103 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 104 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 105 Literature Review e. Ovens Region MONITORING SITE: Site #403241 Ovens River at Peechelba-East. SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 106 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 107 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 108 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 109 Literature Review a. Paroo Region MONITORING SITE: Site #424201 Paroo River at Caiwarro SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 110 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 111 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 112 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 113 Literature Review a. Wimmera MONITORING SITE: Site # 415200; Wimmera River at Horsham SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 114 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 115 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 116 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 117 Literature Review SINCLAIR KNIGHT MERZ G:\Risks to Shared Water Resources Docs\CD2A-R04_bla_WQ_litreview_draft-2Aug2010.docx PAGE 118