2010 Audit of the Sydney Drinking Water Catchment Volume 1 – Main report

Report to the Minister for Water

2010 Audit of the Sydney Drinking Water Catchment Volume 1 – Main report

Report to the Minister for Water

© 2010 State of NSW and Department of Environment, Climate Change and Water NSW. The Department of Environment, Climate Change and Water and State of NSW are pleased to allow this material to be reproduced for educational or non-commercial purposes in whole or in part, provided the meaning is unchanged and its source, publisher and authorship are acknowledged. Specific permission is required for the reproduction of photographs and images.

Published by: Department of Environment, Climate Change and Water NSW 59 Goulburn Street, Sydney PO Box A290 Sydney South 1232 Ph: (02) 9995 5000 (switchboard) Ph: 131 555 (environment information and publications requests) Ph: 1300 361 967 (national parks, climate change and energy efficiency information and publications requests) Fax: (02) 9995 5999 TTY: (02) 9211 4723 Email: [email protected] Website: www.environment.nsw.gov.au

Report pollution and environmental incidents Environment Line: 131 555 (NSW only) or [email protected] See also www.environment.nsw.gov.au/pollution

Cover photos:  Russell Cox Top: Cordeaux River near Pheasants Nest Weir Bottom from left: 1. Fitzroy Falls 2. Gully erosion Wollondilly River sub-catchment 3. Tallowa Dam 4. Agriculture Upper Nepean River sub-catchment

ISBN 978 1 74293 026 8 DECCW 2010/973 November 2010 Printed on recycled paper

Contents

Volume 1: Main report

Summary Recommendations Chapter 1 Introduction ...... 1 1.1 The Sydney Water Catchment Management Act 1998 ...... 1 1.2 Overview of the audit...... 1 1.3 The Sydney Drinking Water Catchment...... 2 1.4 Approach to drinking water quality management ...... 2 Chapter 2 Audit Methodology...... 4 2.1 Overview ...... 4 2.2 Arrangements for the audit ...... 6 2.3 Conduct of the audit ...... 6 2.4 Submissions received...... 9 Chapter 3 Land Use and Human Settlements...... 12 3.1 Land use ...... 12 3.2 Sites of pollution and potential contaminants...... 28 3.3 Soil erosion...... 32 3.4 Population settlements and patterns...... 40 3.5 Community attitudes, aspirations and engagement ...... 42 Chapter 4 Biodiversity and Habitats ...... 47 4.1 Macroinvertebrates...... 47 4.2 Fish ...... 51 4.3 Riparian vegetation...... 56 4.4 Native vegetation...... 62 4.5 Fire...... 68 4.6 Wetlands ...... 75 4.7 Physical form...... 84 Chapter 5 Water Availability ...... 89 5.1 Surface water flows ...... 89 5.2 Environmental flows ...... 103 5.3 Groundwater availability ...... 109

Chapter 6 Water Quality ...... 115 6.1 Ecosystem and raw water quality ...... 115 6.2 Nutrient load...... 141 6.3 Cyanobacterial blooms ...... 154 6.4 Trend assessment...... 165 6.5 Integration of water quality and ecosystem health indicators ...... 173 Chapter 7 Audit Recommendations ...... 174 7.1 Overview ...... 174 7.2 Review of the 2007 recommendations...... 174 7.3 Recommendations from the 2010 audit ...... 183 Acronyms ...... 186 References ...... 189

Volume 2: Appendices

Appendix A: Roles and responsibilities of stakeholders Appendix B: List of parties that responded to the audit Appendix C: Sub-catchment summaries Appendix D: Major projects in the Catchment Appendix E: Water sharing plan management zones Appendix F: Flow exceedance curves Appendix G: River Water Quality

Summary

The Sydney Water Catchment Management Act 1998 (the Act) is the legislation that defines the roles, functions and objectives of the Sydney Catchment Authority. The Sydney Water Catchment Management Amendment Act 2007 requires an audit of the state of the land of the Sydney Drinking Water Catchment (the Catchment) be undertaken every three years, and that a report on this audit be submitted to the Minister responsible for the Sydney Catchment Authority (SCA). The Department of Environment, Climate Change and Water (DECCW) was requested by the Minister to nominate an Auditor to undertake the 2010 audit covering the period 1 July 2007 to 30 June 2010. The audit’s Terms of Reference were to: • assess the state of the Catchment having regard to the catchment health indicators approved under Section 42 of the Act, applicable as at the time of the audit • conduct the audit having regard to the current methodology used in the NSW State of the Environment (SoE) reporting • consult with stakeholders inside and outside the Catchment to seek information and data that may assist with the audit and seek comments relating to the state of the catchment • include long-term trend analysis. The report, Development of Catchment Health – indicators for the drinking water catchments – Sydney, the Illawarra, Blue Mountains, Southern Highlands and Shoalhaven (NOW 2009) listed the catchment health indicators, outlined the process for indicator selection, summarised the recommended methodology for data collection and identified the agencies responsible for collecting indicator data. In this audit, consistency with current methods for SoE reporting for NSW was achieved by using the Pressure-State-Response (PSR) model of environmental reporting. Eighteen indicators were used to quantify and simplify the complex nature of environmental states and pressures and their interactions. The indicators were grouped into four broad themes: Land Use and Human Settlements; Biodiversity and Habitats; Water Availability; and Water Quality. Compared with previous audits, a number of changes were required for the 2010 audit because of: • changes in the indicators used, including the use of new indicators • changes to the period of assessment (three years as opposed to two years in previous audits) • the requirement for long-term trend analysis. Some indicators are less well-developed than others. The change to a three-year reporting timeframe also makes comparisons with previous audits (which covered a two-year period) less meaningful (e.g. when comparing the number of exceedances). The approach taken for such comparisons was, wherever possible, to split long-term data into successive three-year periods and then compare the results. Long-term trend analyses were based on analysis and comparison of percentiles during these successive three-year periods. Flow exceedance curves were also considered when comparing flow in the current audit period with flow in earlier time periods.

The Catchment has been split into 27 sub-catchments. Information was compiled by each sub-catchment to highlight their condition and the pressures on them. However, some indicators did not have sufficient spatial resolution to report at the sub- catchment scale and so they were assessed at either the basin (Hawkesbury– Nepean, Woronora or Shoalhaven River) scale or the whole of Catchment scale. Some major achievements during the current audit period included: • changes to dam and weir infrastructure to enable access to deeper water and the passage of variable environmental flows • restoration of fish passage through the construction and operation of fishways in the Nepean Weirs Project and the fish ‘lift’ on Tallowa Dam • completion of reporting for the Kangaloon borefield project including the dissemination of the results of more than 60 technical, scientific and environmental investigations • exhibition of the Draft Water Sharing Plan for the Greater Metropolitan Region Unregulated River Water Sources (NOW 2010a) • development of the draft Groundwater Sharing Plan for the Hawkesbury–Nepean catchment sources (NOW 2010b). • continued improvements in catchment management through on-ground erosion control, riparian zone rehabilitation, native vegetation rehabilitation, native vegetation replanting, and weed control works • community and landholder involvement in natural resource management • continued monitoring and reporting. Some major issues during the current audit period included: • Delta Electricity’s ‘blowdown’ and mine water discharges in the Upper Coxs River sub-catchment having high concentrations of salt and heavy metals • longwall mining impacts on rivers, streams and swamps and the expansion of coal mining under the Metropolitan and Woronora Special Areas • blue–green algal blooms in Warragamba Dam throughout much of 2007 • water transfers from the Shoalhaven River catchment. The demand to develop land continues to be high throughout the Catchment, particularly in existing urban areas and in the Sydney to Canberra corridor. Many major projects are being dealt with through the Part 3A provisions of the Environmental Planning and Assessment Act 1979. This includes controversial expansions in underground coal mining. Future development is likely to put further pressure on water quality, ecosystem health and land condition in the Catchment areas unless management practices to mitigate their potential impacts are adopted or incorporated. Some licensed discharges have received intensive media scrutiny during the current audit period, in particular Delta Electricity’s ‘blowdown’ discharge. A reduction in the concentration and load of salt and heavy metals from discharges in the Upper Coxs River sub-catchment is considered important for catchment health. Some areas of erosion control and riparian rehabilitation have significantly improved condition in the Catchment. However, further control and rehabilitation is required in other eroded and eroding areas of the Catchment to prevent these areas ‘leaking’ sediments and nutrients to the stream system. Community attitudes, aspirations and engagement have been high with many community members and landholders becoming involved in catchment management programs and projects throughout the Catchment.

The ecosystem health and condition (based on macroinvertebrates, fish, native and riparian vegetation) in many areas of the Catchment is good. However, there are also many areas which are degraded or under considerable pressure from a variety of development and land use activities. The Auditor notes there is currently no broadscale assessment of the condition of wetlands, which are potentially under threat from a range of different sources such as construction, mining, grazing and climate change. The Draft Water Sharing Plan for the Greater Metropolitan Region Unregulated River Water Sources (NOW 2010a) was exhibited during the current audit period. The Auditor notes the NSW Office of Water’s (NOW) assessment that most valleys are at, or close to, the limit of sustainable water extraction. NOW needs to finalise the Draft Water Sharing Plan for the Greater Metropolitan Region to formally establish the rules by which water is extracted from the Catchment ensuring extraction can be limited where such measures are warranted. The Auditor notes that a moratorium on water transfers from the Shoalhaven River catchment is in place which is expected to significantly influence flows in the Wingecarribee and Upper Nepean River due to reduced water transfers. Therefore, flows in the Wingecarribee and Upper Nepean catchments should experience a return to more ‘natural’ flow regimes. Water quality is variable throughout the Catchment as a result of differing land uses and other interacting pressures. Where trend assessments indicate a decline in water quality (e.g. increasing nutrient levels, metal levels, conductivity, chlorophyll a and potentially toxic cyanobacteria or decreasing dissolved oxygen saturation), the reasons behind these declines need to be established. This should lead to management action to arrest the decline and help improve water quality at these sites. At this stage there appears to be limited integration of catchment health indicators throughout the Catchment. An integration of macroinvertebrate, water quality, fish and riparian vegetation condition and assessment would enable a more focused (and better prioritised) management response to stream and catchment condition. Lastly, the Auditor notes that the terms of reference require a focus on the Catchment which effectively ends at the dam (or weir) wall. The audit therefore does not address the impacts of SCA operations and infrastructure, or other interacting pressures, on downstream environments. Other processes are required to address such issues.

Recommendations

Audit Methodology Recommendation 1: The SCA investigate ways to achieve effective Aboriginal community engagement in the audit prior to the commencement of the next Sydney Drinking Water Catchment audit.

Land Use and Human Settlements Recommendation 2: The Department of Planning should undertake detailed consideration of the potential cumulative impacts of all mining activities within the SCA Special Areas. Recommendation 3: Where significant streams and wetlands in the Catchment are impacted by longwall mining there should be a requirement that these impacts are remediated at the expense of the mining company. Recommendation 4: DECCW review licence limits in the Upper Coxs River sub- catchment for all licensed discharge points with a view to reducing the heavy metal and salinity concentrations and loads being discharged to the Coxs River catchment. Recommendation 5: The SCA, HNCMA and SRCMA develop a consistent baseline map of gully erosion for the Catchment.

Biodiversity and Habitats Recommendation 6: The SCA continue to undertake follow-up monitoring at macroinvertebrate monitoring locations that have scored an AusRivAs rating of significantly impaired, severely impaired or extremely impaired where there is no obvious driver for an impacted rating. Recommendation 7: DECCW, in collaboration with SCA, develop a consistent, uniform and integrated vegetation dataset that covers the entire Catchment. Recommendation 8: The Rural Fire Service, in cooperation with SCA and DECCW, integrate their spatial datasets across all sub-catchments so that a single, consistent estimate for the area burnt by hazard reduction burns and bushfires can be reported. Recommendation 9: Lithgow City Council and Centennial Coal should ensure that water transfers from the Clarence Water Transfer Scheme are piped around, rather than flow through, Farmers Creek Swamp. Recommendation 10: DECCW finalise its Draft Upland Swamp Environmental Assessment Guidelines in order to achieve consistency in the application of risk assessment methodology for swamps over areas of longwall mining in the Catchment. Recommendation 11: DECCW and the SCA should finalise their classifications of wetlands to produce a complete and consistent coverage of wetlands in the Catchment.

Water Availability Recommendation 12: NOW should investigate the reasons behind the recent decline in flow in Werriberri Creek. Recommendation 13: The SCA reinstate the flow gauging station in the Little River sub-catchment at Fire Road W4I. Recommendation 14: DECCW, SCA, I&I and NOW investigate the possibility of establishing a collaborative research program aimed at providing a better understanding of the surface water and groundwater hydrology of Thirlmere Lakes and its catchment. Recommendation 15: NOW should investigate the reasons behind the apparent long- term decline in flow in Reedy Creek. Recommendation 16: NOW should finalise the Draft Water Sharing Plan for the Greater Metropolitan Region as soon as practicable. Recommendation 17: NOW and SCA undertake research aimed at understanding the extent, connectivity and interaction between sub-surface aquifers (confined and unconfined), perched aquifers and surface waters within the Catchment.

Water Quality Recommendation 18: The SCA undertake a targeted survey of pesticide usage and application in the catchments of Cascade Dam and Wingecarribee Reservoir. Recommendation 19: The SCA continue to investigate the cause of persistent detections of Cryptosporidium and Giardia oocysts/cysts in the Catchment. Recommendation 20: The operators and regulators of sewage treatment systems in the Catchment should continue efforts to reduce nutrient loads. Recommendation 21: Estimates of nutrient loads from diffuse sources should be included in future audits in order to understand the full context of nutrient loading in the Catchment. Recommendation 22: The SCA should continue to investigate the risk of mixing of cyanobacteria between water bodies in the Shoalhaven system during periods of low flow. Recommendation 23: The SCA should investigate trends and long-term patterns in the community composition of cyanobacteria and phytoplankton in the dams and reservoirs. Recommendation 24: The SCA should look very closely at including monitoring sites in sub-catchments that currently have no long-term water quality or flow gauging sites. Recommendation 25: The SCA collate all recent work undertaken on water quality trend assessments and provide a unifying summary of trends in water quality across the Catchment.

Integration of Water Quality and Ecosystem Health Indicator Monitoring Recommendation 26: The SCA in cooperation with other state and local government agencies explore ways to integrate individual monitoring programs into a broader ecosystem health monitoring program for the entire Catchment.

Recommendation 27: The SCA in cooperation with other state and local government agencies investigate ways of integrating their respective ecosystem health databases so that a common comprehensive database on ecosystem health indicators is developed for the Catchment. Recommendation 28: The SCA ensure these combined databases are readily available to be used in future catchment audits and/or other programs relying on assessments of catchment health.

Chapter 1 Introduction

1.1 The Sydney Water Catchment Management Act 1998 Section 42 of the Sydney Water Catchment Management Act 1998 (the Act) required an audit of the state of the land of the Sydney Drinking Water Catchment (the Catchment) be undertaken every two years, and that a report on this audit be submitted to the Minister responsible for the Sydney Catchment Authority (SCA). This requirement has recently been extended to at least every three years in line with NSW State of the Environment (SoE) reporting (Sydney Water Catchment Management Amendment Act 2007 No 83). Section 42 of the Act also requires that the Minister nominate a person other than the SCA to conduct the audit and prepare the audit report. In 2003 the Minister nominated the Environment Protection Authority (EPA) to undertake the audit of the Catchment. The EPA’s successor organisations, the Department of Environment and Conservation (DEC), the Department of Environment and Climate Change (DECC), and now the Department of Environment, Climate Change and Water (DECCW) have undertaken the 2005, 2007 and the 2010 audits, respectively.

1.2 Overview of the audit The purpose of the 2010 audit is to provide information to all stakeholders about the state of the Catchment during the period from 1 July 2007 to 30 June 2010. Information is provided on the indicators used to assess the pressures on, and changes in, the state of the Catchment over time, by identifying trends in selected indicators where possible. Information from the 2010 audit, and past audits, can be used to guide land managers and the community to make decisions about the management of the Catchment. This is the sixth audit conducted under section 42 of the Act, with previous audits undertaken in 2007, 2005, 2003, 2001 and 1999. The Terms of Reference for the 2010 audit were: • The Catchment audit is required to assess the state of the Catchment having regard to the Catchment Health Indicators approved under section 42 of the Sydney Water Catchment Management Act 1998, applicable as at the time of the audit. • The Catchment audit is to be conducted according to the current methodology used in the SoE reporting for NSW. • Consultation must be undertaken with stakeholders inside and outside the Catchment to seek information and data that may assist with the audit and to seek comments relating to the state of the Catchment. • The audit is to cover the period from 1 July 2007 to 30 June 2010 and also include long-term trend analysis.

Chapter 1 – Introduction 1 1.3 The Sydney Drinking Water Catchment The Sydney Drinking Water Catchment (the Catchment) collects and stores up to 2.6 million megalitres of water to supply Sydney, the Blue Mountains, the Illawarra, the Southern Highlands and parts of the Shoalhaven area with between an average of 1000 and 1500 megalitres of water every day (DECC 2007a). The Catchment is extensive, covering parts of the hydrologic catchments of the Hawkesbury–Nepean, Shoalhaven and Woronora rivers and extending over 16,000 square kilometres. The Catchment extends from north of Lithgow on the Coxs River, from the head of the Shoalhaven River in the south near Cooma, and from the Woronora River in the east to the source of the Wollondilly River west of Goulburn (Figure 1.3.1). The Catchment has been split into 27 sub-catchments. For the purposes of the audit, the Catchment also includes the hydrologic catchment of the Prospect Reservoir in western Sydney.

Priority sub-catchments Previous audit Terms of Reference required the audit to focus on priority sub- catchments. The SCA developed a methodology to identify the priority sub- catchments by assessing the water quality, risk to the SCA reservoir water quality, and stream health. These sub-catchments were: • Kangaroo River • Mulwaree River • Werriberri Creek • Wingecarribee River • Lower Coxs River • Mid Coxs River • Upper Coxs River • Wollondilly River • Upper Wollondilly River. The SCA has since updated its assessment of risk, based on their Catchment Decision Support System (CDSS). The terms of references for the current audit therefore do not specifically require a focus on ‘priority’ sub-catchments; however, these sub-catchments are still important areas for management in the Catchment and are discussed throughout the audit.

1.4 Approach to drinking water quality management The management of drinking water quality in the Catchment uses a multiple barrier approach (NHMRC & NRMMC 2004). The strength of the multiple barrier approach is that a failure of one barrier may be compensated by effective operation of the remaining barriers, minimising the likelihood of contaminants passing through the entire treatment system and being present in sufficient amounts to cause harm to consumers. Traditional preventive measures are incorporated as, or within a, number of barriers, including: • catchment management and source water protection • detention in protected reservoirs or storages • extraction management

2 2010 Audit of the Sydney Drinking Water Catchment

Figure 1.3.1: Sydney Drinking Water Catchment • coagulation, flocculation, sedimentation and filtration • disinfection • protection and maintenance of the distribution system.

Catchment management Catchment management provides the first barrier for the protection of water quality. By decreasing contamination of source water, the amount of treatment and quantity of chemicals needed is reduced. There are a number of agencies that are responsible for aspects of catchment management in the Catchment, these include the SCA, the Office of the Hawkesbury–Nepean (OHN), the NSW Office of Water (NOW – previously the Department of Water and Energy (DWE)), DECCW, Catchment Management Authorities (CMAs) (primarily the Hawkesbury–Nepean and Southern Rivers CMAs; but with small parts covered by the Sydney Metropolitan CMA) and councils. The roles and responsibilities of these and other agencies are outlined in Appendix A. The SCA seeks to provide leadership in catchment protection through a set of tools including regulatory powers, policy development, inter-agency cooperation, research, community education and funding for catchment enhancement works. The SCA operates as an owner, regulator and partner in the management of catchment lands. The Catchment has Special Areas around the water storage areas where access and usage are restricted, and outer catchment areas where land uses such as urban development, mining, agriculture and industrial activities are permitted. An emergent issue for the Special Areas is the recent expansion in longwall mining operations under these otherwise protected areas.

Storage and extraction management The detention of water in reservoirs can reduce the number of faecal micro- organisms through settling and inactivation and allow other suspended material to settle. Where a number of water sources are available, there may be flexibility in the selection of water for treatment and supply. Within a single water body, selective use of multiple extraction points can provide protection against localised contamination either horizontally or vertically through the water column. The SCA’s primary activities in storage management are the selection of water from different storages and from different levels in the storages to meet bulk water quantity and quality requirements, destratification of storages where necessary, and monitoring water quality for a range of parameters.

Water treatment and distribution Waterborne pathogens can cause outbreaks of illness affecting a high proportion of the community and in extreme cases causing death (NHMRC & NRMMC 2004). How much treatment is needed will depend on the level of protection of water supplies. Completely protected groundwater may not require treatment, but all other supplies will require continuous disinfection. If water supplies are not completely protected from human and livestock waste, filtration is likely to be required (NHMRC & NRMMC 2004). Sydney Water and local councils are largely responsible for water treatment and distribution. The SCA is responsible for water treatment and distribution at a number of picnic areas around the dams and reservoirs.

Chapter 1 – Introduction 3 Chapter 2 Audit Methodology

2.1 Overview The 2010 audit Terms of Reference require that current methods used for SoE reporting be adopted. The main assessment tool in SoE reporting is the ‘Pressure- State-Response’ (PSR) model, and this model has been used in this and previous audits.

Pressure-State-Response model The PSR model identifies the cause-effect chains that help us understand and scientifically analyse environmental resource use and problems. The PSR approach assumes that human activities exert pressures on the environment which can induce changes in the state of the environment. Society then responds to changes (in pressure or state) with environmental/economic policies and programs that prevent, reduce or mitigate pressures and/or environmental damage. In this model, indicators are an essential source of information about environmental systems. An indicator quantifies and aggregates data that can be measured and monitored to determine the pressure or state, and to assess whether change is taking place. Accordingly, indicators are selected to provide information about the functioning of a specific system to support decision making and management (Figure 2.1.1).

Pressure State

Human State/condition activities of the environment

Collective and individual responses

Response

Figure 2.1.1: Simplified representation of the Pressure- State-Response model

4 2010 Audit of the Sydney Drinking Water Catchment Audit indicators The catchment audit must assess the state of the catchment area having regard to the catchment health indicators approved under Section 42 of the Act, as in force at the time of the assessment. In October 2008 the Minister for Water, the Hon. Phillip Costa, MP, appointed the DWE (now the NSW Office of Water within DECCW) to develop, approve and publish catchment health indicators for the Catchment area. In consultation with the SCA and other stakeholders, DWE developed a list of 18 gazetted indicators that were approved and published in the NSW Government Gazette on Friday 19 December 2008. The report, Development of Catchment Health - indicators for the drinking water catchments - Sydney, the Illawarra, Blue Mountains, Southern Highlands and Shoalhaven (NOW 2009), listed the catchment health indicators, outlined the process for indicator selection, summarised the recommended methodology for data collection and identified the agencies responsible for collecting indicator data. The 18 approved Catchment health indicators, arranged by themes, are presented in Table 2.1.1.

Table 2.1.1: 2010 audit indicators

Theme Approved indicator

Land use Sites of pollution and potential contamination

Land Use and Human Settlements Soil erosion Population settlements and patterns Community attitudes, aspirations and engagement Macroinvertebrates Fish Riparian vegetation Biodiversity and Habitats Native vegetation Fire Wetlands Physical form Surface water flow Water Availability Environmental flows Groundwater availability Ecosystem and raw water quality Water Quality Nutrient load Cyanobacterial blooms

Chapter 2 – Audit Methodology 5 2.2 Arrangements for the audit

Agreement with the SCA A written agreement was negotiated between the SCA and DECCW for the conduct of the audit. The agreement defined the roles of the SCA as the agency responsible for the administration of the Act, and a nominated member of DECCW as the Auditor in accordance with Section 42 of the Act. The agreement documented the Terms of Reference, an itemised budget and key milestones for the audit, the obligations and undertakings of the parties that ensured the successful completion of the audit, and the primary points of contact within both parties.

The Audit Team The Auditor was Dr Klaus Koop (Director Environment and Conservation Science, DECCW). The Auditor was supported by a project team assembled for the duration of the audit. Team members were: Project Manager: Martin Krogh Senior Project Officer: Jocelyn Dela-Cruz Project Officers: Simon Hunter and Russell Cox

The audit report This audit report was submitted to the Minister in November 2010. In accordance with Section 39 of the Act, the audit report is also to be laid before both Houses of Parliament within the specified one month of being submitted to the Minister. The audit report will also be made available on the DECCW’s and SCA’s websites, and copies will be mailed to interested stakeholders.

2.3 Conduct of the audit

Information gathering The primary data and information sources for the 2010 audit were the SCA, DECCW, CMAs, NOW, the Department of Industry and Investment – Fisheries (I&I Fisheries – formerly DPI Fisheries) and the OHN. These agencies have responsibilities as resource and catchment managers or as coordinators of river management. Data and information for selected indicators were also obtained from the NSW Department of Planning (DoP), Rural Fire Service (RFS), Australian Bureau of Statistics (ABS) and local government authorities. The 2010 audit also sought information from relevant agencies on the nature and extent of actions undertaken in response to the recommendations made in the 2007 audit report. The 2010 audit recognised the potential breadth of knowledge, information and data that may also be available from other stakeholders in the Catchment. Invitations to provide information and submissions were circulated through individual letters and general press advertisements throughout the Catchment. This was achieved by: • directly writing to 66 stakeholders, including relevant government agencies, CMAs, local government, industry associations, local Aboriginal land councils and other non-government organisations

6 2010 Audit of the Sydney Drinking Water Catchment • inviting submissions from the general public through notices in The Sydney Morning Herald, Daily Telegraph, Koori Mail and 21 regional and local newspapers. The newspaper notice text was similar to the written stakeholder invitations, and is reproduced in Figure 2.3.1.

Advertisement Audit of Sydney Water Catchment In accordance with the Sydney Water Catchment Management Act the Minister for Water has commissioned the NSW Department of Environment, Climate Change and Water (DECCW) to undertake an audit of Sydney’s drinking water catchments. The audit is undertaken every three years to provide a snapshot of the health of the catchment. This audit will use a ‘pressure-state-response’ model that examines human pressures on the condition of the Sydney Drinking Water Catchment area. The audit will assess the condition of the catchment using indicators relevant to raw water supply, managing water resources, land condition and ecosystem health. DECCW is inviting interested parties to make a submission presenting any information or data that may assist the conduct of the audit and provide comments relating to the state of the catchment. Please send submissions to: Sydney Drinking Water Catchment Audit c/- Martin Krogh NSW Department of Environment, Climate Change and Water PO Box A290 Sydney South NSW 1232 or email them to: [email protected] The closing date for the receipt of submissions is 13 August 2010. Inquiries regarding the audit and its terms of reference can be made to Martin Krogh on (02) 9995 5619, or Jocelyn Dela-Cruz on (02) 9995 5509.

Figure 2.3.1: Notice inviting submissions

Aboriginal communities in the Catchment The 2010 audit and previous audits before it recognised that Aboriginal communities in the Catchment were stakeholders in the process for a range of reasons. There is Aboriginal presence in the Catchment, both past and present. The Blue Mountains National Park, Nattai Conservation Area and other reserves around the Catchment are known to contain some of the most culturally significant sites of Aboriginal

Chapter 2 – Audit Methodology 7 occupation of the land. Parts of the Catchment are Country for the Deerubbin, Dharawal, Pejar, and other Aboriginal peoples. Aboriginal communities own significant tracts of land in the Catchment. For the past 3 audits, the Auditor wrote to the NSW Aboriginal Land Council, extending an invitation for them to make a submission. The 2010 Auditor also extended the invitation to five local Aboriginal land councils in the Catchment. The 2010 invitation to make a submission on the existing audit indicators did not receive any responses from any of the Land Councils. The Auditor notes that the current audit timeframe is too short for effective Aboriginal community engagement. The Auditor is aware that the SCA, DECCW and the CMAs in the Catchment have officers and programs whose core businesses include effective engagement of Aboriginal communities on a range of government activities. DECCW’s Aboriginal Cultural Heritage Consultation Requirements for Proponents (DECCW 2010a) relates primarily to the issuing of Aboriginal Heritage Impact Permits, however, it could also be used as to guide for consultation in the context of the audit. The Auditor believes that a communication and engagement package for effective Aboriginal community engagement still needs to be developed for future audits. This may require more time than that traditionally allocated to the audit process.

Recommendation 1: The SCA investigate ways to achieve effective Aboriginal community engagement in the audit prior to the commencement of the next Sydney Drinking Water Catchment audit.

Catchment inspections The Audit Team undertook catchment inspections in August, September and October 2010 in order to view some of the specific localities and premises that represented known issues in the Catchment. Some areas (e.g. Upper Coxs sub-catchment) had already been visited previously as a result of previous DECCW studies. Officers from the SCA, DECCW and/or the Hawkesbury–Nepean CMA (HNCMA) accompanied the Audit Team at different times and locations and provided expert advice on catchment management issues. Issues of particular interest to the Audit Team during the current audit included: • creek bed cracking and swamp impacts (in areas where longwall mining has already occurred) • point source pollution and/or remediation (e.g. sewage treatment plants, mines, erosion sites, rehabilitation sites) • areas of land use change. Catchment inspections occurred at the following locations: • Upper and Middle Coxs River and Farmers Creek around Lithgow • Mulwaree and Wollondilly Rivers around Goulburn • Nepean River catchment, Wingecarribee River and Reservoir, and the Kangaloon Borefield in the Southern Highlands • Kangaroo River, Tallowa Dam, Bendeela Pondage and Fitzroy Falls Reservoir. • Waratah Rivulet (Woronora River) • Thirlmere Lakes.

8 2010 Audit of the Sydney Drinking Water Catchment The outcomes and findings from the inspections are incorporated into case studies and the following chapters of this audit report.

2.4 Submissions received Thirty-five submissions were received from a range of State Government agencies, Local Government Agencies, environmental groups, mining and power companies, the NSW Minerals Council and private individuals. The Audit Team acknowledged all submissions in writing and has used the information and data provided. Individuals and organisations that provided a submission are listed in Appendix B. Information, data and issues from the submissions were compiled and catalogued, and information identified for later analysis within their appropriate theme(s) and indicator(s) (see Table 2.1.1). Many submissions canvassed more than one issue and a summary of the issues raised is provided in Figure 2.4.1. The most frequent issue raised was that of mining impacts, particularly those associated with water flow, water quality and wetlands. A brief discussion of the major issues identified in submissions follows:

Mining impacts Ten submissions were received regarding longwall mining, particularly in the Upper Nepean and Woronora Special Areas. Submissions that raised issues about longwall mining came from the OHN, SCA, local councils (Campbelltown and Sutherland), environment groups (4 organisations) and two private individuals. The NSW Minerals Council submission (not counted in the 10 above) emphasised the economic and social benefits of mining in these areas.

Water quality Eight submissions were received regarding water quality. The primary catchments involved were: the Upper Nepean/Woronora catchments because of longwall mining (licensed colliery discharges were also raised but this occurs in the nearby Upper Georges River catchment); the Upper Coxs River because of Delta Electricity’s licensed discharge (and other licensed discharges); and the Kangaroo River sub- catchment (pathogens and turbidity/suspended solids).

Flow Eight submissions were received regarding water flow. This included concerns about environmental flow releases under Water Management Licences (e.g. Delta Electricity’s Water Management Licence for the Upper Coxs River) or the potential for reduced or no flow as a result of longwall mining.

Chapter 2 – Audit Methodology 9

Figure 2.4.1: Issues identified in submissions to the 2010 audit

Wetlands Six submissions were received regarding wetlands. These were all related to longwall mining impacts.

Development Six submissions were received regarding development in the catchments. Some of the major issues raised were about upstream developments affecting downstream environments, inappropriate development, and rural subdivision. Licensed discharges Five submissions were received regarding licensed discharges. This included Delta Electricity’s discharge, mining company discharges and sewage treatment plant discharges. Compliance Five submissions were received regarding compliance. This included concerns about meeting State Plan targets, illegal dumping, Special Areas enforcement, auditing of success of the Healthy Catchments Program (HCP) and perceived weak legislation.

10 2010 Audit of the Sydney Drinking Water Catchment On-site systems Four submissions raised the issue of on-site systems with some of these systems identified as failing. Monitoring Four submissions raised the issue of monitoring. Some called for increased monitoring while others raised the issue of public access to monitoring data. Algae Four submissions raised the issue of algae and/or cyanobacterial blooms. Other Three submissions each raised the issues of cumulative impacts and sustainability; pests and weeds; fish passage, fish kills and pest fish species; and fire. Two submissions each raised the issues of Riparian Zone Management; Recreational Use; Public Health – pathogens; Implementation of Recommendations; Groundwater, and Erosion. Other single issues identified included: Water Balances; Adequacy of Vegetation Mapping; Stormwater; Population Growth; Implementation of the Neutral or Beneficial Effect test; Land Use; Land Capability; Geomorphology; Farming Practices; Farm Dams; Education; and Contaminated Sites. Where relevant, case studies were identified to highlight issues, utilising information provided by stakeholders in their submissions and from observations made during catchment inspections. The 2010 audit recognises that many pressures (e.g. land clearing and erosion, development etc) occur throughout all or most of the sub-catchments; whereas other pressures (e.g. mining and power station discharges) are restricted to one or just a few of these sub-catchments. Where detailed information is available, the 2010 audit has compiled and presented information on a sub-catchment basis to highlight the state of individual sub-catchments and the variety of pressures on them (see Appendix C).

Chapter 2 – Audit Methodology 11 Chapter 3 Land Use and Human Settlements

3.1 Land use

Background Land use is an important pressure in the catchment and a clear understanding of land use is critical in identifying the likely impacts this usage has on water quality in drinking water storages. Change in land use can result from the transfer of one type of land use to another or as a result of changes in the intensity of land use. Examples include moving from native pasture to improved pasture, pasture to cropping or intensive agriculture and agriculture to urban or rural residential. Land use change has the potential to increase the pressure on ecosystem health and water quality in the Catchment, and yet also offers the opportunity in some cases to reduce impacts from past land uses and poor land management practices. Land use mapping of the entire Catchment is not currently undertaken at a frequency which enables an assessment of land use change at three-year audit intervals. Further, land use changes over a three-year audit period are likely to be relatively minor on a Catchment-wide scale. The assessment of land use change at a Catchment-wide scale is therefore a more useful longer term measure of the pressures on land condition. The recommended indicator for land use is the type and extent of land use in the Catchment (NOW 2009). The 2010 Audit used the latest land use map developed by the SCA (see Figure 3.1.1). This map was initially developed under contract by the former DIPNR, now part of DECCW. The mapping was completed in 2006 and an update by DECCW was incorporated in 2008. Since then the SCA has undertaken its own land use change mapping using the nationally recognised Australian Land Use and Management (ALUM) Classification system. This latest map also incorporated land-use changes identified from 2009 aerial photography. The 2010 Audit describes the type and extent of current land use, and provides a quantification of the extent of land use change since 2006. Additional information is provided on development applications (DA) and major project applications in the Catchment, including a case study on longwall mining.

Findings

Current land use Land use across the Catchment is shown in Figure 3.1.1. Conservation and natural areas occupy approximately half of the Catchment area (50.4%). The Little River, Kowmung, Endrick and Lower Coxs River sub-catchments have the greatest area of land assigned to conservation or natural areas (Figure 3.1.2). Large areas of land are used for grazing activities (36.3%), specifically in the Kangaroo River, Upper Nepean River, Back Creek and Round Mountain Creek, Braidwood, Wingecarribee River, Wollondilly River, Bungonia Creek, Mulwaree River, Mid Shoalhaven River,

12 2010 Audit of the Sydney Drinking Water Catchment

Figure 3.1.1: Percentage of land use area in the Catchment, 2010

Source: DIPNR 2005, Data from SCA 2010 Nerrimunga River1, Upper Coxs River, Jerrabattgulla Creek, Mongarlowe River and Reedy Creek sub-catchments (Figures 3.1.1 and 3.1.2). Large urban areas are located at Goulburn (Mulwaree River sub-catchment); Bowral, Mittagong and Moss Vale (Wingecarribee and Nattai River sub-catchments); Lithgow (Upper Coxs River sub-catchment); and Katoomba (Lower Coxs River sub-catchment). There are also large rural residential areas in the Wollondilly River and Nerrimunga River sub- catchments. The Upper Coxs River, Back Creek and Round Mountain Creek and Jerrabattgulla sub-catchments have the largest proportion of land occupied for forestry purposes (> 25%).

Land-use change since 2006 Since 2006 there has been a shift to more intensive land use in some sub- catchments, including areas of land which were previously pasture lands that are now used for forestry purposes. Such changes were identified in the Back Creek and Round Mountain Creek (2080 ha) and Bungonia Creek (132 ha) sub-catchments. Expansion of urban and rural residential areas into pasture lands has also occurred in the Bungonia Creek (1108 ha), Nerrimunga River (424 ha) and the Wollondilly River (396 ha) sub-catchments. A summary of the area and type of land-use changes that have occurred in the Catchment since 2006 is provided in Table 3.1.1

Development applications The demand for development of land in the Sydney to Canberra corridor continues to increase (DOP 2008), with the majority of applications (received by the SCA) originating from the large regional centres in the Catchment such as Goulburn in the Goulburn–Mulwaree local government area (LGA), and Bowral, Mittagong and Moss Vale in the Wingecarribee LGA. The largest number of development applications requiring concurrence by the SCA during the 2010 audit period were for the Goulburn–Mulwaree and Wingecarribee LGAs, 304 and 509, respectively (Figure 3.1.3). In contrast to the Wingecarribee LGA, where development activity has declined since the last audit, land use change has increased significantly in the Goulburn–Mulwaree LGA. In particular, there have been many new approvals for additional residential and industrial developments in the Goulburn–Mulwaree LGA. The number of development applications requiring concurrence by the SCA for other parts of the catchments are as follows: Blue Mountains – 53, Kiama – 2, Lithgow – 139, Palerang – 122, Shoalhaven – 62, Upper Lachlan – 68, Wollondilly – 33 and Wollongong – 10. Unsewered dwellings and dual cccupancy DAs were the most common form of DA concurrence sought from the SCA in each of the LGAs (Table 3.1.2). The highest number of DAs for unsewered dwellings and dual cccupancy were in the Shoalhaven LGA (69.4% of Shoalhaven LGA DAs), followed by Palerang LGA (60.7% of Palerang LGA DAs). DAs for rural subdivisions were most common in the Wingecarribee LGA (63 or 12% of DAs) and Lachlan LGA (23 or 33.8% of DAs). The number of DAs seeking urban subdivision was highest in the Goulburn–Mulwaree LGA (18 or 6% of DAs)

1 The Auditor notes the inconsist terminology for Nerrimunga, being called both a river and a creek in various government documents. The correct name according to the Geographical Names Board is ‘Nerrimunga Creek’, however, the term ‘Nerrimunga River sub-catchment’ has been used in the audit text for consistency with the Regional Plan document (SCA 2007).

Chapter 3 – Land Use and Human Settlements 13 100%

80%

Abandoned or degraded land Conservation or natural areas Cultivation or intensive agriculture 60% Forestry Grazing or improved pastures Mining, manufacturing or industrial Natural water and wetlands 40% Services or recreation

-catchmnetSub area (%) Transport and utilities Urban and rural residential Waste disposal 20%

0% eek r la C lla Little Little River Boro Boro Creek Nattai Nattai River Reedy Creek Reedy Endrick Endrick River Mid Coxs Mid Coxs River Kangaroo River Kangaroo Mulwaree Mulwaree River Kowmung River Kowmung Woronora River Bungonia Creek Bungonia Wollondilly River Wollondilly Werriberri Creek Upper Upper Wollondilly Braidwood Creek Braidwood Upper Coxs Upper Coxs River Lower Lower Coxs River Lake Lake Burragorang Mongarlowe Mongarlowe River Nerrimunga Nerrimunga Creek Jerrabattgu Upper Nepean Upper River Nepean Wingecarribee Wingecarribee River Mid Shoalhaven River Mid Shoalhaven Upper Shoalhaven River Upper Shoalhaven Grose River - MtnsBlue Back Ck & Round Back & MtnCk Round Ck

Sub-catchment

Figure 3.1.2: Land use in the sub-catchments, 2010 Note: All percentages shown are percentage of the total sub-catchment area. Source: Data from SCA 2010

14 2010 Audit of the Sydney Drinking Water Catchment Table 3.1.1: Area (hectares) of 11 land use change classes mapped since 2006 using 2009 aerial photography for the sub-catchments

Cultivation Grazing Natural Abandoned Conservation or or Mining, water Services Transport Urban or or degraded or natural intensive improved manufacturing and or and rural Waste land areas agriculture Forestry pastures or industrial wetlands recreation utilities residential disposal

Back Creek & Round Mtn Creek 2216 5 Boro Creek 21 Braidwood Creek 25 Bungonia Creek 17 129 5 150 3992 4 1 7 54 1801 Endrick River 10 4 Jerrabattgulla Creek 2216 Kangaroo River 4 Little River 35 Mid Coxs River 33 4 7 13 6 Mid Shoalhaven River 916 29 227 Mongarlowe River 20 924 6 102 Mulwaree River 36 62 5398 20 154 16 123 Nattai River 4 23 6 63 18 Nerrimunga River 20 29 15 3 5922 2 40 844 Reedy Creek 9 5 132 65 422 Upper Coxs River 7 3019 156 22 394 93 Upper Nepean River 17 51 9 Upper Shoalhaven River 295 Upper Wollondilly 173 26 127 5 2358 3 4 31 226 1 Werriberri Creek 12 3 Wingecarribee River 29 145 44 107 28 32 83 Wollondilly River 50 6424 23 87 3226 17 119 739 87 Source: Data from SCA 2010 Note: Areas of land-use change were not identified by the SCA in the Kowmung River, Lower Coxs, Lake Burragorang, Grose River and Woronora River sub-catchments.

Chapter 3 – Land use and Human Settlements 15 Table 3.1.2: Type of development application (DA) concurrence advice by LGA, provided by the SCA during the 2010 audit period. The number of concurrence advices are shown for each LGA. Percentages (in brackets) represent total number of DA concurrence advices for each LGA.

Development type Goulburn Blue Kiama Lithgow Palerang Shoalhaven Upper Wingecarribee Wollondilly Wollongong Mulwaree Mountains Lachlan Boundary Adjustment 1 (0.3) 1 (0.7) 1 (1.6) 6 (1.2) Subdivision Commercial 26 (8.5) 10 (18.9) 1 (50) 10 (7.2) 1 (0.8) 2 (2.9) 30 (5.9) 1 (3.0) 1 (10.0) DAM Wastewater Modelling 1 (3.0) Assessment DAs Out of REP Catchment 1 (1.9) 3 (0.6) Earthworks/Roads/Car 1 (0.3) 1 (1.9) 3 (2.2) 2 (3.2) 3 (0.6) 1 (3.0) Parks/Farm Dams Extractive 1 (0.3) 1 (0.7) Industries/Quarries/Pt4 Mines Horse Stable 1 (1.5) 17 (3.3) 4 (12.1) Industrial 12 (3.9) 3 (5.7) 3 (2.2) 1 (0.8) 12 (2.4) 1 (3.0) Industrial Subdivision 3 (1.0) 1 (0.7) 4 (0.8) Intensive Livestock excl Horse 2 (0.7) 3 (0.6) Stable/Poultry Farm Intensive Plant Growing other 1 (0.3) 1 (1.6) 1 (0.2) 1 (3.0) than Vineyards Mine Ancillary Works 1 (3.0) Multi-dwelling - sewered 6 (2.0) 5 (9.4) 1 (0.7) 2 (0.4) Multi-dwelling - Unsewered 1 (0.2) Other 14 (4.6) 1 (1.9) 8 (5.8) 5 (4.1) 4 (6.5) 2 (2.9) 26 (5.1) 4 (12.1) 6 (60.0) Other Unsewered WW incl L 2 (0.7) 2 (1.4) 3 (2.5) 7 (1.4) 1 (3.0) Govt Act upgrades Poultry Farm 2 (0.7) 1 (0.8) Rural Subdivision 53 (17.4) 1 (1.9) 18 (12.9) 31 (25.4) 7 (11.3) 23 (33.8) 63 (12.4) 5 (15.2) 1 (10.0) Service station 5 (1.6) 1 (0.7) 1 (1.6) 2 (0.4) Sewered Dwelling/Dual 4 (1.3) 7 (13.2) 4 (2.9) 4 (0.8) 2 (6.1) Occupancy

16 2010 Audit of the Sydney Drinking Water Catchment Development type Goulburn Blue Kiama Lithgow Palerang Shoalhaven Upper Wingecarribee Wollondilly Wollongong Mulwaree Mountains Lachlan STP/Biosolids 1 (0.3) 1 (0.7) 1 (1.5) 1 (0.2) Application/Landfill Tourism/Recreation/Religious 8 (2.6) 4 (7.5) 12 (8.6) 6 (4.9) 3 (4.8) 15 (2.9) 1 (10.0) Unsewered Dwelling/Dual 144 (47.4) 20 (37.7) 1 (50) 69 (49.6) 74 (60.7) 43 (69.4) 39 (57.4) 288 (56.6) 11 (33.3) 1 (10.0) Occupancy Urban Subdivision 18 (5.9) 4 (2.9) 19 (3.7) Vineyards 2 (0.4) Source: Data from SCA 2010

Chapter 3 – Land use and Human Settlements 17 600

500

400

300

200 Number of Number applications of 100

0 Kiama Blue Lithgow Palerang Goulburn Mulwaree Mountains Wollondilly Shoalhaven Wollongong Wingecarribee Upper Lachlan Upper Local government area

Figure 3.1.3: Number of development applications requiring concurrence that were processed by the SCA for the 2010 audit period

Major project applications A summary of major projects in, or adjacent to, the Catchment are included in Appendix D. Many large developments in the Catchment are now being dealt with through the Part 3A provisions of the Environmental Planning and Assessment Act 1979 (EP&A Act). Development applications under Part 3A provisions are determined by the Minister for Planning and not by local councils. The SCA does not have a concurrence role in such developments, although they are consulted by the Department of Planning (DoP) before and after exhibition of major projects. This situation is particularly the case for new coal mining applications, many of which can cover large areas of the Catchment. There are large areas of land in the Catchment subject to mining production title (Figure 3.1.4). The Upper Nepean River sub-catchment has 47,384 hectares and over 50% of this area is occupied by current mining production title, much of this within the SCA Metropolitan Special Areas. Collectively, 52% of the SCA Metropolitan and Woronora Special Areas land are under current mining production title. Mining production title also covers 32% of the Upper Coxs River sub- catchment and 8% of the Wingecarribee River sub-catchment (Industry and Investment 2010). An expression of interest is also out for the expansion of mining production title in the East Bargo coal exploration area, which underlies the junction and lower gorges of the Cordeaux, Avon and Nepean rivers (DPI 2009).

18 2010 Audit of the Sydney Drinking Water Catchment 50000

40000

30000

Area (ha) Area 20000

10000

0 River Lake River River Little River Little River Upper Upper Coxs Burragorang Upper Upper Nepean Wingecarribee Mid Coxs Mid River Woronora River Woronora Mid Shoalhaven Mid River Mulwaree Bungonia Creek Bungonia Wollondilly River Wollondilly Werriberri Creek Werriberri

Sub-catchm e nt

Figure 3.1.4: Area of land in the Catchment under current mining production title Source: Data from Industry and Investment NSW (2010)

Case Study 1: Longwall mining During the current audit period, the NSW Government completed the Southern Coalfield Inquiry which reviewed the state of knowledge on longwall mining and its associated impacts (DoP 2008b). The Southern Coalfield Inquiry identified that the Southern Coalfield was a major source of high quality hard coking coal used for production of steel, both in Australia and overseas. Eight currently operating mines in the Southern Coalfield produce around 11 Mt of coal annually with the majority (98%) using longwall mining methods (DoP 2008b). Coal mining has high economic and social significance for the communities of the Southern Coalfield and directly employs about 2500 people. Indirect employment may be as high as 12,000 (DoP 2008b). Coal royalty income from the Southern Coalfield was $58.7 million in 2006–07 (DoP 2008b). However, if not well-managed mining can have, and has had, a significant impact on rivers, streams, creeks, wetlands and groundwater resources. The greatest number of submissions to the audit were related to the impacts of longwall mining in the Catchment, in particular, in the Upper Nepean and Woronora River sub-catchments. Submissions to the audit and submissions to the DoP on recent major coal mining environmental assessments imply that some natural resource agencies, councils and sections of the community do not believe the right balance between socio-economic benefits and environmental outcomes are currently being achieved for longwall mining operations in the Catchment. The Southern Coalfield Inquiry (DoP 2008b) identified the following impacts associated with longwall mining: • tensile and shear cracking of the rock mass • localised buckling of strata caused by valley closure and upsidence • formation of subsidence depressions or troughs. The environmental consequences of these impacts included: • loss of surface flows to the subsurface • loss of standing pools • adverse water quality impacts

Chapter 3 – Land Use and Human Settlements 19 • development of iron bacterial mats • cliff falls and rock falls • damage to Aboriginal heritage sites • impacts on aquatic ecology • ponding. Other impacts were identified for upland swamps with a ‘significant possibility that undermining of valley infill swamps could cause drainage, water table drop and consequent degradation to swamp water quality and associated vegetation’ (DoP 2008b). More recent data has identified further impacts to a range of other upland swamp types, including the ‘headwater’ swamp type discussed by the Southern Coalfield Inquiry (BHPBIC 2009, NSW Planning Assessment Commission 2009; Aurecon 2009a; DECCW 2009a). Longwall mining can also impact groundwater aquifers through subsidence, strata movements and drainage. Subsidence and strata movements affect groundwater by deforming existing fractures, enlarging existing fracture apertures, creating new fractures, separating bedding planes, and changing the hydraulic properties of the strata. As a result, the piezometric levels can decline; baseflow discharge to streams can reduce; groundwater flow patterns can alter; aquifers can change from confined to unconfined, causing water quality changes; and upper aquifers can leak to lower aquifers (Booth 2002, 2006, 2007; Booth et al. 1998, Madden and Merrick 2009, Madden and Ross 2009). The severity of these impacts often increase with the degree of subsidence experienced, the degree of topographic incision above the mine and the sensitivity of the surface features located directly above the mined panels. Major recommendations from the Southern Coalfield Inquiry included: • identifying Risk Management Zones (RMZs) in order to focus assessment and management of potential impacts on significant natural features • applying RMZs to all streams of 3rd order or above in the Strahler stream classification • applying a precautionary approach, due to the extent of current knowledge gaps, to the approval of mining which might unacceptably impact highly-significant natural features • increased monitoring and assessment requirements when approving mining within identified RMZs • determining the acceptability of impacts within a framework of risk-based decision making, under Part 3A of the EP&A Act, • providing improved guidance by the government to both the mining industry and the community on the significance and value for natural and other environmental feature to inform company risk management processes, community expectations and government approvals. Other recommendations were made regarding subsidence impact management, prediction of subsidence effects and impacts and environmental baseline data.

Current mining approvals Until relatively recently, underground coal mining that had the potential for surface subsidence, were approved under section 138 of the Coal Mines Regulation Act 1982 and/or the Mining Act 1992 (DMR 2003). Most recent coal mine proposals in NSW are now being approved under the Part 3A provisions of the EP&A Act. Following the Southern Coalfield Inquiry, the first major new coal mine in the Catchment to be approved under the Part 3A provisions was the expansion of Peabody Coal’s Metropolitan Colliery.

Peabody Coal – Metropolitan Colliery expansion The Minister for Planning referred the Metropolitan Coal Project to the Planning Assessment Commission (PAC) for review and for advice on the acceptability of the potential impacts and

20 2010 Audit of the Sydney Drinking Water Catchment any other significant issues raised in submissions or public hearings (NSW Planning Assessment Commission 2009). The Metropolitan Colliery Project involves mining underneath the Woronora Reservoir and Special Areas (Helensburgh Coal 2008). The longwall panels applied for under Waratah Rivulet and much of its catchment were of similar width (165 m) to those that had previously caused extensive damage to Waratah Rivulet (e.g. see Galvin and Associates 2005). Where the longwall panels went directly under Woronora Reservoir, however, the panel widths were reduced to 130 m and pillar widths increased to 70 m to reduce the risk of impacts to Woronora Reservoir (Helensburgh Coal 2008). Regarding surface water, the PAC for the Metropolitan Coal Project found that: • the potential loss of catchment yield was a strongly contested issue that could not be resolved beyond doubt on the information available • the environmental consequences for watercourses impacted by subsidence could be severe • the environmental consequences from the preferred project were unacceptable for specific sections of the Waratah Rivulet and Eastern Tributary • mining should be allowed to proceed under other watercourses • site water management became a significant issue due to upwardly revised estimates of mine water from those presented in the Environmental Assessment (EA). Regarding groundwater, the PAC for the Metropolitan Coal Project found numerous deficiencies that made it difficult to conduct a proper assessment of the potential groundwater impacts, but that on the balance of probabilities impacts on groundwater were unlikely to be significant. Regarding swamps, the PAC for the Metropolitan Coal Project found that for most swamps in the project area there was a low risk of negative environmental consequences and that there was a very low risk that a significant number of swamps would suffer such consequences. The PAC noted there were significant deficiencies in the EA and Preferred Project Report in relation to prediction of non-conventional subsidence impacts at swamps and that this led to concerns that a small number of swamps might be at risk from this source. It was considered desirable that further work be undertaken to establish the nature and extent of any such risk before the undermining of these swamps could proceed. The PAC recommended the project proposal as set out in Peabody Coal’s Preferred Project Report be approved subject to a broad-ranging suite of strict conditions (NSW Planning Assessment Commission 2009).

BHP Billiton Illawarra Coal Holdings Pty Ltd – Appin-West Cliff Mining Complex – Bulli Seam Project BHP Billiton Illawarra Coal Holdings Pty Ltd (BHP Billiton) has applied for the Bulli Seam Project to be assessed under Part 3A provisions of the EP&A Act. This project was also referred to PAC. The proposal covers approximately 220 km2 of the Upper Nepean, Upper Georges and Upper Woronora River catchments (BHPBilliton 2009). Large parts of the mine plan fall within the Catchment boundaries, particularly areas under the Metropolitan and Woronora Special Areas. The proposed panel widths for the Bulli Seam Proposal (310 m) are nearly double those of Metropolitan mine. Based on predicted subsidence levels for this mine, between 65 km (DECCW 2009a) and 72 km (BHPBilliton 2009) of mostly third order or above streams are likely to experience subsidence (including valley closure and upsidence effects) that has the potential for fracturing of rock strata in the streambed and diversion/draining of water into the shallow subsurface fracture network created by undermining. Further, of the 226 upland swamps occurring above the proposed mine, 55 (or 24.3%) of these swamps are predicted to experience impacts, with the worst impacts likely to fracture the relatively impervious base of the swamps leading to the loss of their perched aquifers (DECCW 2009a). Concerns were also raised about the apparent lack of

Chapter 3 – Land Use and Human Settlements 21 commitment in the EA to remediation of the total length of stream network likely to be affected by the mining proposals (e.g. DECCW 2009a). The PAC findings for the Bulli Seam Project are yet to be released2 and a decision is yet to be made on BHP Billiton’s Preferred Project Report for the Bulli Seam Project. DECCW (2009a) recommended a staged approval approach to this mine with mining in the Eastern Domains, which contains the most sensitive upland swamp areas and Dharawal State Conservation Area, delayed until there was greater knowledge and certainty about its impacts.

Other coal mining proposals Other proposals for coal mining in the Catchment, which were determined under Part 3A (EP&A Act) during the audit period; and are currently being assessed; or are in the process of being prepared for assessment, under Part 3A include: • Angus Place Mine • Baal Bone Mine • Invincible Mine • Lamberts Gully Mine • NRE No. 1 Mine • Pine Dale Mine • Wongawilli Mine. An expression of interest is also currently out for the East Bargo area which underlies the confluence of the gorges of the Cordeaux, Avon and Nepean Rivers (see Section 4.6 Longwall mining impacts on wetlands, Figure 4.6.5). This area also underlies the Pheasants Nest water supply weir. Cockatoo Coal is also reported to have recently invested in the Sutton Forest site, which is estimated to hold 115 million tonnes of export grade coking coal and thermal coals (Southern Highland News 2010).

Remediation To date there is insufficient scientific evidence to demonstrate that remediation of streams and wetlands have generally been successful at returning these systems to pre-mining conditions (AWT 2000, DIPNR 2003, Krogh 2007, DECCW 2009a). DECCW (2009a) identified that remediation of longwall mining fractures in the streambed had been attempted in the: • Cataract River (bentonite grouting) • Upper Georges River – Marhnyes Hole to Jutts Crossing • Waratah Rivulet (sand curtains, polyurethane injection). Grouting of the most severe crack in the Cataract River was undertaken in 1999 but deemed only partially successful (AWT 2000). Remediation in the Upper Georges River in the vicinity of Marhnyes Hole has not been demonstrated to have led to a return to natural flows and pool water retentions that existed prior to mining and a major concern was that releases from Brennans Creek Dam were masking impacts from previous undermining (DECCW 2009a). One area where intensive remediation efforts have recently been employed is at a major rockbar (denoted WRS3) in Waratah Rivulet. This area was visited by the audit team in September 2010. Subsidence induced cracking occurred in Waratah Rivulet as a result of the undermining of Metropolitan Colliery longwalls (particularly longwalls 10, 11 and 12). An initial attempt was undertaken to remediate the rockbar (and restore pool levels in the large

2 The PAC report was released on 27 October 2010, but there was insufficient time to incorporate their findings in the current audit.

22 2010 Audit of the Sydney Drinking Water Catchment pool behind the rockbar that had been drained; see Figure 3.1.5) using sand curtains. An unquantified amount of this sand ended up being flushed through the fracture network and deposited downstream. As a result, pool levels upstream of the rockbar were not restored to their original condition and pool level recession after rainfall events was ongoing (DECCW 2009a).

Figure 3.1.5: Waratah Rivulet – Pool A above WRS3 rockbar after fracturing and draining in 2005 (left) and Pool A at the time of visit by the audit project team, September 2010 (right) Note: Arrows indicate rock used as reference point for pool level measurements.

Polyurethane resin has recently been injected into the rockbar to try and seal the fracture network. At the time of the Audit team’s visit this appears to have potentially been successful with pool levels stabilising at near their previous levels (Figures 3.1.5 and 3.1.6). While a full analysis of pool level data over a longer period of time is still required to confirm these findings, this is considered to be a promising outcome of remediation in Waratah Rivulet. There has, however, been a significant cost associated with this remediation work (understood to be between $5 and $10 million and approximately 170,000 L of polyurethane resin). It is noted that other pools in Waratah Rivulet are yet to be fully remediated and further impacts are likely downstream in Waratah Rivulet as a result of Metropolitan’s expanded mine plan. Any impacts to these areas should also receive appropriate remediation. Assessments of the effect of these remediation efforts on water quality, aquatic biota and the level of iron-oxidising bacteria in the stream bed still needs to be undertaken.

Chapter 3 – Land Use and Human Settlements 23

Figure 3.1.6: Pool A levels measured in Waratah Rivulet Note: Circled area indicates more consistent water levels in recent times. Source: SCA 2010a. Rainfall data is from Darkes Forest gauge (BOM data).

Longwall mining implications Coal mining is one of the most significant industries in NSW and has seen an upward trend of 2% in production from 2007–08 to 2008–09 (NSW Minerals Council 2009). It is likely there will be ongoing pressure to access coal reserves in the Catchment. Where longwall panels pass under sensitive surface features such as streams and swamps there is the potential for severe impacts to occur, including loss of surface water flow, loss of standing pools and loss of the perched aquifers within swamps. This can have flow-on effects to aquatic and swamp- associated fauna and flora, including threatened species (DECCW 2009a). Where water is lost to the shallow subsurface fracture network, the mining companies are yet to provide unequivocal scientific evidence that all of this water returns to the river network (Krogh 2007, PAC 2009, DECCW 2009a). Impacts to deep and shallow groundwater aquifers can also occur (DECCW 2009a, Booth 2002, 2006, 2007; Booth et al. 1998, Madden and Merrick 2009, Madden and Ross 2009). The Auditor notes that: • at least eight large coal mining applications are currently before DoP or are proposed for assessment under Part 3A (EP&A Act) in the very near future • approximately 52% of the Metropolitan and Woronora Special Areas are subject to current mining production title (an even larger area if exploration title is included) • current mining development assessments are usually made on a single mine-by-mine basis. Given the extent of current impacts, the extent of mining title and the likelihood of future coal mining impacts in the SCA Special Areas, DoP should undertake detailed consideration of the potential cumulative impacts of all such mining activities within the SCA Special Areas. This is particularly important for Part 3A applications, but also extends to exploration

24 2010 Audit of the Sydney Drinking Water Catchment activities where multiple access tracks or easements are created and/or vegetation cleared within the SCA Special Areas. While it is acknowledged that results from recent remediation efforts in Waratah Rivulet appear to have been effective in restoring pool levels behind one rockbar, it is also recognised that the cost of this remediation was significant ($5–$10 million). The Auditor is also aware that there are currently no scientifically proven remediation methods known that are capable of restoring perched aquifers in swamps once they are fractured and drained (DECCW 2009a). Where significant streams and wetlands are impacted by longwall mining in the Catchment there should be a presumption that these impacts will be remediated at the mining company’s expense. Costs for remediation should also be accounted for by mining proponents when undertaking socio-economic assessments of mining proposals in the Catchment. While subsidence impacts can be avoided or reduced by altering panel layouts and/or reducing the width of longwall panels, there is likely to be a continuing debate between natural resource agencies, environmental groups, mining industries, DoP and the general public about what level of impact is deemed to be ‘acceptable’ in these areas. The degree of impacts that have already occurred and the magnitude of potential impacts associated with major proposals such as that of the Bulli Seam Project raise significant concerns for the Auditor about the long-term ecological sustainability of current mining practices in the Upper Nepean and Woronora Special Areas, particularly when there is little or no remediation work undertaken.

Recommendation 2: The Department of Planning should undertake detailed consideration of the potential cumulative impacts of all mining activities within the SCA Special Areas.

Recommendation 3: Where significant streams and wetlands in the Catchment are impacted by longwall mining there should be a requirement that these impacts are remediated at the expense of the mining company.

General implications The demand for development continues to be high, particularly in the sub-catchments of the Wingecarribee and Goulburn–Mulwaree local government areas. The Goulburn Mulwaree Council is in the process of developing a new Local Environmental Plan (LEP) and Strategy Plan which will provide statutory information about land use, including future specific objectives and zoning information. The Strategy Plan 2020 will provide detailed guidance about the future direction of the area over the next 15 years. The Sydney–Canberra Corridor Regional Strategy 2006–2013 (DoP 2008a) will guide future planning and development in the catchments in the future. The Regional Strategy is an initiative of the NSW Government and will aim to underpin sustainable growth throughout the Sydney–Canberra corridor until 2031. Several sub-catchments have the potential for growth and development in the future for housing and settlement as set out in DoP (2008a).

Wingecarribee River sub-catchment • Bowral – the majority of greenfield development will be located in Mittagong with 1000 lots and Moss Vale with 1400 lots planned for in the short to medium term.

Mulwaree River sub-catchment • Goulburn with an infill capacity of up to 1300 dwellings and a major greenfield release at Marys Mount on the North West side of Goulburn with a capacity of approximately 1000

Chapter 3 – Land Use and Human Settlements 25 dwellings. The potential development of greenfield land at Kenmore and additional Marys Mount releases on the outskirts of Goulburn (with a combined potential of approximately 1000 dwellings).

Bungonia Creek sub-catchment • Marulan – additional housing will be addressed through Goulburn Mulwaree Council’s 2020 Strategy and LEP.

Braidwood Creek sub-catchment • Braidwood is within commuting distance of Canberra so is predicted to have some commuter based growth. Sub-catchments in the following local government regions are likely to have a major land use change associated with residential and industrial development associated with rezoning which occurred during the 2010 audit period (Planning NSW’s submission to the audit 2010).

Wingecarribee • Broughton Vale rezoning in 2009 of rural land to residential (approximately 400 lots) • Moss Vale Enterprise corridor rezoning of 570 hectares of land from rural to general industrial • East Mittagong (Renwick) – rezoning of 600 lots from special uses and reserved land to residential.

Goulburn Mulwaree • Marys Mount (1878 lots) zoned from rural to residential and industrial • Marulan Estates – 600 lots zoned from rural to residential and industrial • Kenmore (150 lots) zoned from special uses to residential • Woodlawn Mine (major project) zoned to industrial (currently operating as a waste facility). Other Major Projects being assessed or currently proposed for assessment under the Part 3A provisions (EP&A Act) in the Catchment include: • coal mines • gold mine • coal seam gas projects • rail link corridors • gas-fired power stations • freight lines • wind farms • waste facility • water transfer projects • quarries • distribution hubs • ash placement projects • power station extensions • sand projects • clay/shale projects • regional shooting complexes • sewerage scheme modifications.

26 2010 Audit of the Sydney Drinking Water Catchment If not well managed, all these proposals have the potential to significantly affect the state and response of the Catchment. Future development is likely to put further pressure on water quality, ecosystem health and land condition in the Catchment areas and sub-catchments unless specific management practices are adopted or incorporated to mitigate the potential impacts of vegetation clearing, soil erosion, subsidence-induced fracturing of rock strata, stormwater, and sewage management associated with these developments. Under the REP, developers are required to comply with the SCA’s Current Recommended Practices (CRPs) or adopt practices and standards that will achieve the same outcomes as the CRPs. However, there appears to be little information regarding the degree of uptake and extent of individuals/organisations implementing recommended practices. The Auditor understands that the SCA referral requirements focus on all development proposals in LGAs (including those with potential sewage management issues) which may impact on the water quality in the Catchment. Other development proposals that could affect local stormwater quality, and which may also have an impact in the Catchment, are not referred to SCA. Data on this broader dimension of development pressure in the Catchment was not provided to the Auditor. Many large developments in the Catchment are now being dealt with through Part 3A provisions (EP&A Act). Development applications under Part 3A provisions are determined by the Minister for Planning and not by local councils. The SCA does not have a concurrence role in such developments. Information on major projects within the Catchment boundary can be found on the DoP’s Major Project register. Other changes in land use, such as improvements to pasture, through cultivation and application of fertiliser, are more difficult to quantify as they are not subject to planning approval processes. Similarly, changes in management practices can also lead to changes in the state and condition of land in the catchment, but again such changes are difficult to quantify.

Future directions Given the anticipated rate of land use change across the Catchment it is envisaged that land use maps could be updated at five-year intervals depending on advances in remote sensing technology and analysis. Such maps provide useful information for catchment managers and land use planners in identifying where there are changing pressures on land condition, water quality and ecosystem health, and concurrently provide a useful layer of information for modelling other catchment indicators. Given these potential uses of detailed land maps, the Auditor considers that the SCA should have an interest in ensuring such land use maps remain up to date, and reinforces the recommendation made in 2007 that detailed land use maps be updated every five years. Changes in land use, particularly those changes leading to the removal of native vegetation and disruption of soil almost inevitably lead to increased impact on land condition and water quality. However, with appropriate design and management, such impacts can be minimised and could potentially lead to improved outcomes, especially where degraded landscapes are rehabilitated and best practice water-sensitive design principles are implemented. The SCA’s Raw Water Quality Risk Management Framework and rectification action planning process should enable high risk locations and land uses to be identified. The next step would be to identify the areas in which there is potential for improved management practices. Various agencies have already published best management practice guidelines and the SCA has its own ‘Current Recommended Management Practices’. For example, the SCA’s PROGRAZE and LANDSCAN programs (SCA 2009a) provided on-farm training for graziers during the course of the audit period. Similarly, the HNCMA has a joint (with SCA and private landholders) program titled ‘Improving Land Management Practices’ that improved grazing practices across 1800 hectares in the Catchment. Such programs help

Chapter 3 – Land Use and Human Settlements 27 foster sustainable management practices that can reduce the adverse water quality impacts of grazing (e.g. increased runoff and loss of vegetation cover) in the catchment. The development of guidelines and training for the use of a stormwater model (MUSIC) by the SCA will also support local council’s abilities to assess the impacts from new development in the Catchment. This would help minimise the risk to water quality from pressures of complex developments such as industrial sites or large urban and rural subdivisions. The future development and implementation of web-based tools/guidelines by the SCA will play a role in future strategic land use planning and will assist councils to undertake NorBE assessments (Neutral or Beneficial Effect on water quality) for development applications which occur in the Catchment in the future. The rural residential subdivision design guide currently being developed by the SCA will also help developers and councils ensure that new subdivisions proposed in rural areas have a neutral or beneficial effect on water quality in the Catchment. Regional planning strategies including the Sydney–Canberra Corridor Regional Strategy, will guide future planning and development in the Catchments. The Regional Strategy is an initiative of the NSW Government and was designed to underpin sustainable growth throughout the Sydney–Canberra Corridor until 2031. Further guidelines should be developed for remaining high-risk activities and management practices.

3.2 Sites of pollution and potential contaminants

Background Many industrial or agricultural processes can pollute the land during operation and/or by leaving a legacy of contaminated materials. Land pollution and contamination can occur where appropriate management practices are not implemented. Land contamination can potentially be mobilised by surface and groundwater movement and erosion, resulting in migration of contaminants into the broader Catchment. Therefore, it is important to identify operational and historical sites in the Catchment that have a potential to contaminate land and pollute water. The previous audit (DECC 2007a) reported on many potential pollution sources in the Catchment. DECC’s (2007a) assessment was based on a considerable amount of work undertaken by the SCA over the last decade. Much of the information was sourced from the SCA’s Pollution Source Risk Management Plan (SCA 2000) and the Environmental Assessment of Sites and Infrastructure (EASI) assessments. The EASI assessments were undertaken for commercial and manufacturing facilities, commonwealth facilities, intensive horticulture/forestry, intensive livestock industries, sewage and water treatment, telecommunications and energy production, waste disposal, mines and quarries. The EASI process identified 1776 sites of pollution or potential contamination in the Catchment. During the last audit the SCA updated its assessments of potentially polluting sites with the total number of sites in the SCA’s Compliance Support System increasing from the original 1776 EASI sites to 2391 sites. Of these, 1381 priority sites were reassessed, with 65 sites rated as very high risk to water quality, 195 sites as high risk, 246 sites as medium risk, 500 sites as low risk and 315 sites as negligible risk (see DECC 2007a). In developing their CDSS, the SCA (2009b) recently developed a spatial, index-based methodology to assess pollution source hazards within the catchments. This is carried out by a specifically designed spatial analysis tool known as the Pollution Source Assessment Tool (PSAT) (SCA 2009b). The PSAT is a processing framework that can accept and manipulate many forms of data and/or expert knowledge. It consists of:

28 2010 Audit of the Sydney Drinking Water Catchment • a comprehensive pollution source database with the ability to store region or site-specific information about the local conditions and management practices relevant to each pollution source type • a database enabling the input criteria used, and the weightings between them, to be entered and adjusted • a suite of spatial datasets relating to landscape and climate factors • an ArcGIS script that automatically converts inputs to hazard indices, applies weightings and combines inputs to produce pollution source hazard estimates • a set of outputs, both in spatial and table form. The PSAT provides a comprehensive and repeatable qualitative assessment of the hazard from a range of pollution sources across the Catchment. It is a diagnostic tool designed to identify activities and locations likely to be significant long-term pollution sources – irrespective of the type or frequency of the events that might mobilise and deliver those pollutants. The pollution source assessment incorporates 14 modules, each addressing a key catchment activity or potential pollutant source (see Table 3.2.1). The modules were chosen to provide coverage of all significant pollution sources within the Catchment.

Table 3.2.1: Potential pollution source by module

Module Pollution sources covered Grazing Land grazed by all stock types including beef cattle, dairy cattle, sheep, horses, goats and alpacas. Horticulture and cropping Broad-acre cropping, orchards, viticulture, potato growing, market gardens, berries, olives, nuts and cut flowers. Intensive animal production Abattoirs (external component – processing component is considered in industry module), dairies (cows and goats), horse studs, kennels, piggeries, poultry farms and saleyards. Urban stormwater All urban stormwater catchments. Sewage treatment plants Large STPs. Small package STPs such as those operated for (STPs) tourist parks are not currently included due to lack of data. Sewage collection systems All sewer infrastructures including pipes and pumping stations. Excludes STPs and on-site wastewater management systems. On-site wastewater All on-site systems, including pump-out systems, septics, management systems irrigation and trench systems. Roads All public roads, including fire trails, tracks, sealed and unsealed rural roads, urban roads, highways and motorways. It does not cover private farm tracks. Industry Includes power stations, coal processing plants, abattoirs (processing components), automotive workshops, service stations, car dealerships, fuel depots, concrete batching plants, transport depots, wool scours, landscaping supplies and large- scale food production. Mines and quarries Coal mines, metalliferous mines, oil shale mines and quarries. Both operational and non-operational mines are assessed. Landfills At present only considers municipal type landfills. Rural and farm dumps are excluded due to lack of data. Forests All areas mapped by land cover mapping as having native vegetation or pine plantation. Includes public and privately owned forested land. Streambank erosion Rivers Gully erosion Mapped drainage lines and streams Source: SCA (2009b)

Chapter 3 – Land Use and Human Settlements 29 The CDSS was used to identify the pollution source issues that were of greatest importance to the SCA in terms of pollution risk to the water supply storages. This produced a list of 235 pollution source issues, spread across the catchments (SCA 2009b). A further prioritisation assessment of catchment actions was then undertaken yielding a list of the top 100 priority issues for 2009 (see SCA 2009b). Further details on the sub-catchment, drainage unit, pollution source category and pollution source ratings are discussed in the individual sub- catchment section at Appendix C.

Compliance under the Protection of the Environment Operations Act 1997 DECCW regulates major point sources of potential pollution using Environment Protection Licences issued under the Protection of the Environment Operations Act 1997 (POEO Act). Activities that require an Environment Protection Licence include industries in certain categories and at higher levels of activity, sewage treatment systems (STSs), electricity generation and waste facilities (Chapter 6, Section 6.2). The licences include requirements for pollution control, monitoring, and reporting. There are 88 sites in the Catchment that are licensed under the POEO Act (DECC 2007a).

Case study 2: Upper Coxs River licensed discharges Local environment groups and the Environmental Defenders Office have publicly raised concerns about unnaturally high concentrations of heavy metals in the Upper Coxs River and its tributaries. These metals were claimed to be present at elevated concentrations with respect to environmental guidelines and were suggested to be having a negative impact on both the river environment and the quality of Sydney’s drinking water. The environment groups claimed that the elevated metals were directly attributable to the coal mining industry and to the two Delta Electricity power stations. In July 2008 and February 2009 the DECCW and the SCA undertook a joint sampling program of the Upper Coxs River. The samples were analysed for an extensive range of contaminants including heavy metals. The results of this sampling indicated that a number of heavy metals were present in water samples at concentrations greater than ANZECC/ARMCANZ (2000) guideline values. These metals included aluminium, boron, copper, nickel and zinc. Articles in The Sydney Morning Herald (SMH, 2 December 2008, p.5; SMH 18 June, 2009, p.1; SMH, 19 June, 2009, p.1) highlighted potentially toxic concentrations of other heavy metals, for example arsenic and fluoride, from the Wallerawang Power Station discharge (often referred to as the ‘blowdown’). Follow-up water quality and macroinvertebrate sampling by DECCW in September–October 2009 confirmed a number of areas where contaminant levels were relatively high. It is understood that in response to these concerns, Delta Electricity has implemented a number of improvements aimed at reducing salt loads and contaminants in its discharges to the Coxs River catchment. Delta is also currently in the process of constructing a reverse osmosis plant at Wallerawang Power Station and a pipeline to Mt Piper Power Station for treatment (Delta Electricity submission 2010a). DECCW has also been working closely with industry to try and address these issues. The following sections provide a summary of the results of analyses of water quality and macroinvertebrates in the Upper Coxs River catchment (DECCW 2010b).

30 2010 Audit of the Sydney Drinking Water Catchment Water quality in the Upper Coxs River sub-catchment

Heavy metals Analysis of total and dissolved metal levels in water samples collected from the Upper Coxs River catchment identified 4 distinct clusters of sites: 1. sites associated with and downstream of Wallerawang blowdown discharge 2. sites associated with Neubecks Creek 3. sites associated with Sawyers Swamp Creek below the ash dam 4. all other sites (with generally lower dissolved metal levels). The water quality analyses indicated that dissolved metals and total metals were generally higher in waters downstream of the Wallerawang blowdown discharge, in Neubecks Creek and in Sawyers Swamp Creek below the ash dam. Relatively increased metal levels in water samples could be identified for at least 6–7 km downstream from the Wallerawang blowdown source (DECCW 2010b).

Salinity Salinity is also an important issue in the Upper Coxs River and there are concerns about saline discharges affecting the aquatic ecology above and below Lake Lyell. Salinity has previously been shown to have an impact on species retention rates in the Victorian and South Australian streams (Kefford et al. 2010) with species retention rates often decreasing as salinity levels increased. Wallerawang blowdown discharges are currently around 2500 µS/cm conductivity, while those of the minewater discharges are typically around 1200 µS/cm. Streams high up in the Catchment typically have much lower conductivity levels (often between 20 and 100 µS/cm). If the major salt ions (sodium, calcium, magnesium and potassium) are considered, then the blowdown discharge and Neubecks Creek sites are identified as having elevated salt ion levels. The salt signature of minewater discharges is also very similar to that of the blowdown discharge. This is not surprising since minewater is currently transferred from Centennial Coal’s operations to Delta Electricity and subsequently used for cooling water purposes. Some concentration of salts in the blowdown discharge is expected simply due to evaporation. Investigation of historic water quality data generally indicated that, since the 1960s–1990s, salinity levels have noticeably increased in the Coxs River at locations upstream of the Wallerawang Power Station, downstream of the Great Western Highway, at Lake Lyell and downstream of Lake Lyell as far as Duddawarra.

Nutrients In contrast to the metals and salt data, the nutrient data indicate alternative sources for the majority of nutrients in the Coxs River catchment. Sites in Farmers Creek downstream of Lithgow township and the Lithgow STP have elevated nutrient levels compared to most other sites in the catchment. Nutrient levels in Lake Lyell are also often elevated as a result of inflows from both Farmers Creek and the Upper Coxs sub-catchment. While recent improvements have been made to the Lithgow STP, this remains an important source of elevated nutrients in the Coxs River catchment. In addition, the urban areas around Lithgow are also potential contributors to elevated nutrients in Farmers Creek and Lithgow Council has recently undertaken an assessment of the environmental impacts of the sewerage collection systems (Aurecon 2009b).

Chapter 3 – Land Use and Human Settlements 31 Macroinvertebrates in the Upper Coxs River sub-catchment Elevated contaminants in water were considered to be having an effect on the aquatic biota, including macroinvertebrates. DECCW sampled a large number of sites for macroinvertebrates in the Coxs River catchment in September–October 2009. The fauna assemblages at most sampled sites in the Coxs River catchment were dominated by pollution-tolerant taxa such as worms and chironomids. This was particularly evident in the Coxs River between the Neubecks Creek confluence and Lake Lyell; Farmers Creek downstream of the STP and Lithgow township; Neubecks Creek; and Sawyers Swamp Creek. The site on Kangaroo Creek downstream of the Angus Place discharge was found to have a depauperate macroinvertebrate community. Analyses indicated that the invertebrate assemblages were influenced by the elevated salinity levels, with the assemblages of sites with elevated conductivity and salts being more similar to each other than to other sites with lower conductivities. There were two caddisfly genera, three mayfly genera and two dipterans that were collected only from sites of lower conductivity. Dragonflies and damselflies were less common at sites of higher salinity, and the total number of taxa collected from each site was generally lower with increasing conductivity. The invertebrate fauna collected from Farmers Creek downstream of the STP were indicative of nutrient pollution, having low diversity and being dominated by dipterans and oligochaetes.

Conclusion The major conclusions of the DECCW (2010b) assessment were that: • salinity and metals were elevated in river reaches of the Upper Coxs River sub- catchment as a result of power station and mine water discharges, mine water runoff and re-use • nutrients were elevated downstream of Lithgow township and STP • these water pollutants were having a detrimental effect on the aquatic biota. As a result of the above conclusions the Auditor considers that a reduction in the salt and metal loads in the Upper Coxs River sub-catchment is highly desirable and necessary. While efforts by industries have been made to reduce the level of contaminants in their discharges, at this stage this is not sufficient to protect the ecosystem health of the waterways. The Auditor therefore recommends that the Environmental Protection Licence limits for these discharges be reviewed with a view to reducing the heavy metal and salinity concentrations and loads being discharged to the Coxs River catchment.

Recommendation 4: DECCW review licence limits in the Upper Coxs sub-catchment for all licensed discharge points with a view to reducing the heavy metal and salinity concentrations and loads being discharged to the Coxs River catchment.

3.3 Soil erosion

Background Soil erosion is a natural process that can be accelerated by human activities. The risk of erosion is linked to a range of factors, such as land use, geology, geomorphology, climate, soil texture, soil structure and the nature and density of vegetation in the area. The clearing of native vegetation and agricultural land use activities have been major contributors to accelerated rates of erosion. The potential for soil erosion increases wherever vegetation cover is removed, soil is disturbed or exposed, and where high intensity rainfall or wind occurs. The main categories of soil erosion are sheet, rill, gully, tunnel, stream bank and

32 2010 Audit of the Sydney Drinking Water Catchment wind erosion. The management of areas with erosion risk, and the remediation of areas that are affected by soil erosion, are important in protecting land productivity, water quality and ecosystem health. The report on the development of Catchment health indicators (NOW 2009) indicated that the most prominent form of soil erosion in the Catchment area is gully erosion, which is readily observable and measurable (see also Armstrong and Mackenzie 2002). As such gully erosion is the recommended measure for this indicator. Stream bank erosion is also included in the present audit because it results from similar land use activities, has the same potential impact on water quality and aquatic ecosystem health, and is also a dominant source of sediment to the rivers (Armstrong and Mackenzie 2002). The findings presented below arise from mapping undertaken in the mid 1980s through aerial photo interpretation (API) and extensive ground-truthing (Emery 1986). As a consequence, the data set is still being used by both the HNCMA and Southern Rivers Catchment Management Authority (SRCMA) as a baseline data set for prioritising soil conservation works in the Catchment area. This data set contains information on the location and extent of gully and stream bank erosion. Extent is estimated through the length of erosion rather than area as the data are presented as vectors. The extent of gully erosion is, however, further defined by four classes of severity: minor, moderate, severe and extreme. A relatively new data set on active gully erosion, developed by the SCA, is also discussed below. The data set identifies gullies in the Catchment that are ‘active’, that is, when soil is being washed away from the gully walls during rain events. The data set was used in the 2007 audit to describe the total area of gully erosion in the Catchment area. For the present audit, the dataset is used to describe the total area of active gully erosion in each sub- catchment.

Findings The vector data set on gully and stream bank erosion (used by HNCMA and SRCMA) indicates that at the time of mapping, there was 649.3 km of streambank erosion and 2345.1 km of gully erosion in the Catchment area (Figure 3.3.1). Around 34% of the gully erosion was considered to be minor, 32% moderate, 22% severe and 12% extreme. Most of the gully and stream bank erosion is concentrated in sub-catchments where the sodic sub-soils are highly erodible such as the Wollondilly River, Upper Wollondilly River, Mulwaree River and Nerrimunga River sub-catchments (Table 3.3.1). Accordingly gully and streambank remediation efforts have focused on these areas, with resourcing predominantly leveraged from the SCA’s Catchment Protection Scheme (SCA 2009c). Figure 3.3.2 shows the extent of soil conservation works undertaken by HNCMA since 2004, when the authorities were first formed. Such works include bank stabilisation, gully filling, gully shaping, fencing, planting of riparian vegetation, and installation and/or maintenance of flumes, gully control structures (e.g. silt traps) and diversion banks (see Box 3.3). Collectively, the works have resulted in 638 km of remediated stream banks and over 142 km2 of remediated gullies. Since the 2007 audit a total 48 soil conservation projects were completed under the SCA’s Catchment Protection Scheme. Specific works include: • 65.43 km2 of land treated/protected for soil erosion by soil engineering works • 7.71 km2 of land treated for erosion by fencing • total of 513 km of stream bed and banks stabilised • 80 gully control structures constructed • 119 flumes constructed • 398 banks constructed • 59 grade stabilisation structures (rock/log) constructed.

Chapter 3 – Land Use and Human Settlements 33 Table 3.3.1: Length of gully and streambank erosion (km) and area of active gully erosion (km2) in the Catchment. Gully erosion is categorised into four classes – extreme, severe, moderate and minor.

Sub-catchment Extreme Severe Moderate Minor Bank Active Back Creek/Round 6.1 17.4 22.5 17.7 29.9 0.326 Mountain Creek Boro Creek 26.2 22.6 16.8 12.7 29.1 0.560 Braidwood Creek 5.8 19.6 13.4 15.4 19.0 0.339 Bungonia Creek 11.5 17.2 47.0 20.6 52.2 0.611 Cascade Creek 0.0 0.0 0.0 0.0 0.0 0.000 Endrick River 3.1 3.8 4.7 4.5 8.5 0.007 Jerrabattgulla Creek 1.3 4.6 13.9 15.2 22.3 0.228 Kangaroo River 0.0 0.0 2.5 2.5 1.4 0.003 Kowmung River 0.0 0.0 0.0 1.7 1.1 0.105 Lake Burragorang 0.0 0.0 0.0 1.0 0.0 0.000 Lake Greaves 0.0 0.0 0.0 0.0 0.0 0.000 Little River 0.0 4.0 0.0 4.0 2.4 0.070 Lower Coxs River 0.0 1.2 0.0 0.0 1.0 0.000 Mid Coxs River 6.6 38.7 49.9 27.9 25.2 0.126 Mid Shoalhaven 32.1 31.9 21.2 13.6 16.3 0.069 River Mongarlowe River 11.0 13.4 15.1 9.1 6.0 0.010 Mulwaree River 14.7 34.3 67.0 64.4 33.2 0.859 Nattai River 0.0 4.0 0.0 4.0 2.4 0.070 Nerrimunga River 18.7 26.4 46.2 37.1 41.1 0.306 Reedy Creek 6.5 11.2 20.3 58.1 19.4 0.458 Upper Coxs River 5.2 4.7 20.5 14.0 12.8 0.078 Upper Nepean River 0.0 0.8 2.6 1.4 1.2 0.039 Upper Shoalhaven 0.0 0.0 0.0 3.2 7.4 0.000 River Upper Wollondilly 29.9 88.7 152.2 157.3 95.8 1.173 River Werriberri Creek 0.0 0.0 0.0 0.0 0.0 0.000 Wingecarribee River 0.2 8.1 7.0 7.4 19.5 0.104 Wollondilly River 112.6 166.3 228.6 298.5 204.6 2.269 Woodford Creek 0.0 0.0 0.0 0.0 0.0 0.000 Woronora River 0.0 0.0 0.0 0.0 0.0 0.000 Source: Emery 1986; SCA 2005 Note: Data on gully and stream bank erosion arise from mapping undertaken in the mid 1980’s, whereas data on active gully erosion arise from mapping undertaken in mid 2000.

34 2010 Audit of the Sydney Drinking Water Catchment

Figure 3.3.1: Historical gully and streambank erosion in the Catchment

Figure 3.3.2: Map showing the location of soil conservation works in the HNCMA region Source: HNCMA 2010

Chapter 3 – Land Use and Human Settlements 35 Box 3.3: Soil conservation works at Arthursleigh

'Arthursleigh' (7900 ha) is located in the Wollondilly sub-catchment. The property was donated to the University of Sydney in 1979 from the estate of the late Eric Thomas Wallis Holt. The property currently consists of a mixed farming enterprise that includes merino sheep, cattle and fodder cropping (HNCMA, 2010). Prior to this, the property was poorly managed and experienced severe land degradation and erosion (DECC 2007a). Active gully erosion at a property near Arthursleigh (August 2010)

A long history of soil conservation works have taken place on Arthursleigh, which date back to the mid 1970s (HNCMA 2010). The works were aimed at stabilising active gully erosion and minimising downstream movement of sediment and turbid water. Examples of such work were observed during the catchment inspections for the audit:

1. Diversion banks – 73 constructed 2. Fencing –72 km

3. Gully control/Silt traps –19 constructed 5. Streambank stabilisation – 31km

36 2010 Audit of the Sydney Drinking Water Catchment An example of the extent of works undertaken by the SRCMA in the Upper Shoalhaven and Kangaroo Valley is shown in Figure 3.3.3. The works include a range of historical Catchment Protection Scheme projects that predate the SRCMA, as well as newer projects under that scheme and the Southern Bushland Incentives projects. With the exception of figures from the Illawarra Shoalhaven Dairy Partnership project, the total length of streambank remediated is estimated to be 39.3 km and the total area of gully remediated 3 km2. Specific figures for the current audit period are as follows: • 1.98 km2 of land treated/protected for soil erosion by soil engineering works • 1 km2 of land treated for erosion by fencing • 5 km of minor/moderate eroding gullies stabilised • 7.3 km of severe to extreme eroding gullies stabilised • total of 52 km of stream bed and banks stabilised.

The total area of active gully erosion in the Catchment area is estimated to be 7.76 km2. The sub-catchments with the greatest area of active gully erosion are Wollondilly, Upper Wollondilly, and Mulwaree (Table 3.3.1, Figure 3.3.4). The SCA has also identified the following sub-catchments, where erosion is a risk to water quality: Bungonia Creek, Braidwood, Jerrabattgulla Creek, Boro Creek, Reedy Creek and Nerrimunga River. In addition to the support provided to the HNCMA and SRCMA (through the CPS), the SCA has undertaken a range of erosion control activities in Braidwood where there has been broad- scale vegetation clearing for agriculture and mining. Remediation works were also undertaking in Wingecarribee Swamp (see Wingecarribee sub-catchment summary in Appendix C).

Chapter 3 – Land Use and Human Settlements 37

Figure 3.3.3: Map showing the location of soil conservation works in the SRCMA region Source: SRCMA 2010

38 2010 Audit of the Sydney Drinking Water Catchment

Figure 3.3.4: Active gully erosion in the Catchment Implications and future directions The impacts of gully erosion and streambank erosion are two-fold, the first being the loss of available land (for uses such as agriculture) and acceleration of drainage and aridification. The second being the delivery of large amounts of sediment to rivers and streams. Within the Catchment, the Wollondilly River, Upper Wollondilly River, Mulwaree River and Nerrimunga River sub-catchments have the greatest number of eroding gullies and streambanks. Recent modelling by the Commonwealth Scientific Industrial Research Organisation (CSIRO) suggests that 67,000 tonnes of sediment per year arises from the gullies and streambanks in the Wollondilly River sub-catchment, 6200 tonnes from the Upper Wollondilly and 3700 tonnes from the Mulwaree (Rustomji 2006). The potential extent of this sediment delivery was observed at Arthursleigh in the Wollondilly River sub-catchment during the audit catchment inspections (Box 3.3). Overall, 68,555 tonnes of sediment per year was estimated to originate from the gullies and streambanks in the 12 sub-catchments that drain into Lake Burragorang (Rustomji 2006). According to the CSIRO modelling, the extent of sediment delivered by gully and streambank erosion in the Lake Burragorang sub-catchment has declined and is outweighed (> 3 times) by hill slope erosion in predominantly steep forested areas (Rustomji 2006). The estimates are based on the assumption that 40 t/km2/y of sediment is exported from forested areas. While the export rate may be greater than expected (Section 6.2, see also Armstrong and Mackenzie 2002), these results highlight the important contributions from hill slope erosion. Significant efforts are currently underway by DECCW to collect local data on hill slope soil erosion and to incorporate this data into spatially explicit models (Revised Universal Soil Loss Equation) that predict sediment loss at monthly time scales. Through this work, local field observations of erosion are being supplemented by (fractional ground cover) data arising from advanced remote sensing techniques to ensure high spatial resolution. Given this future availability, it is recommended that future audits include an assessment of both gully and hill slope erosion. The different methods of reporting gully and streambank erosion has made it difficult to provide consistent estimates of the extent of erosion in the Catchment area. As indicated above, over the last decade a great deal of remediation work has taken place through various projects meaning that the figures provided in Table 3.3.1 for gully and streambank erosion are potentially overestimated. The SCA, HNCMA and SRCMA are working towards development of a database (Land Management Database) containing spatial information on the extent of gully and streambank erosion remediated in the Catchment. Such a database is obviously useful for updating the original 1980s mapping used by the CMAs and the recent active gully erosion mapping used by the SCA. For this to take place, however, there needs to be some rationalisation/relationships drawn between the different erosion maps in order to develop a consistent map of gully and streambank erosion in the Catchment. Box 3.3 provides examples of the types of remediation works undertaken in the Catchment as a result of programs such as the Catchment Protection Scheme. The Auditor recognises the benefits of these programs and the clear need for such programs to continue.

Recommendation 5: The SCA, HNCMA and SRCMA develop a consistent baseline map of gully erosion for the Catchment.

Chapter 3 – Land Use and Human Settlements 39 3.4 Population settlements and patterns

Background Population settlements and patterns across the Catchment have not been shown in previous audits. Population growth has an obvious potential to impose extra demands on infrastructure and natural resources. Such demands result in increased pressure on water resources in the catchment, both in terms of quantity and quality. Data to inform population settlements and patterns were sourced from the Australian Bureau of Statistics (ABS) and DoP. The highest resolution of spatial data acquired for the present audit arises from the ABS 2006 Census, where data is presented for each Census Collection District (ABS 2010a). This data was digitally mapped to produce specific population statistics (total and density) for each of the 27 sub-catchments within the Catchment area. More recent statistics (to June 2009) on rates of annual population growth and future projections are only available on an LGA basis. Data is presented for the 6 LGAs where most of the LGA area was within the Catchment.

Findings At June 2006, the total population in the Catchment was 115,877 people. The majority (70%) of the population reside in 6 of the 29 sub-catchments within the Catchment area (Figure 3.4.1). The Wingecarribee sub-catchment was the most populated (23,476 people) followed by Mulwaree River (14,325), Upper Coxs River (13,356), Nattai River (10,902), Lower Coxs River (10,155) and Upper Wollondilly River (8,725) sub-catchments. On an areal basis, the Woodford Creek sub-catchment (1.68 people.ha-1) had the greatest average population density, followed by Lake Greaves (0.45 people.ha-1) sub-catchment. The Lower (0.41 people.ha-1) and Upper (0.35 people.ha-1) Coxs River, Wingecarribee (0.31 people.ha-1), Nattai (0.24 people.ha-1) and Werriberri Creek (0.24 people.ha-1) sub-catchments had moderate population densities (Figure 3.4.2). The smallest population densities (<0.02 people.ha-1) occur in sub-catchments in the south of the Catchment area such as the Upper Shoalhaven River, Jerrabattgulla Creek and Endrick River sub-catchments (Figure 3.4.2). The change in annual population between 2001 and 2009 in LGAs is shown in Figure 3.4.3. All LGAs experienced net population growth over the 8-year period (Figure 3.4.3a). Average annual population growth was greatest in the Palerang LGA, increasing at an average rate of 3.5 % between 2001 and 2009 (Figure 3.4.3b). Such growth is among the highest reported for inland areas in NSW (ABS 2010b). The lowest rates of annual population growth were in the Lithgow (0.25 %) and Upper Lachlan LGAs (0.41 %) (Figure 3.4.3b).

40 2010 Audit of the Sydney Drinking Water Catchment

Figure 3.4.1: Total population in the Catchment at June 2006

Figure 3.4.2: Population density (people/km2) in the Catchment at June 2006 a) net population change, 2001 to 2009 (total number of people)

Wollondilly

Wingecarribee

Upper Lachlan Shire

Palerang

Lithgow

Goulburn Mulw aree

0 1000 2000 3000 4000 5000 6000

b) average annual population change, 2001 to 2009 (%)

Wollondilly

Wingecarribee

Upper Lachlan Shire

Palerang

Lithgow

Goulburn Mulw aree

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00

Figure 3.4.3: Population changes in the LGAs of Wollondilly, Wingecarribee, Upper Lachlan Shire, Palerang, Lithgow and Goulburn Mulwaree Source: DoP 2010a and 2010b

Chapter 3 – Land Use and Human Settlements 41 Future projections of population growth have been summarised by DoP (2010a and b). The projections show that by 2036, the populations in the Wollondilly, Palerang and Wingecarribee LGAs will be approximately 36%, 30% and 23% (respectively) greater than the current population. Most of the growth in the Palerang and Wollondilly LGAs, however, is projected to occur outside of the Catchment. By 2036, the populations in the Lithgow and Upper Lachlan LGAs are projected to decrease by 10 and 7 % respectively. The population in the Goulburn Mulwaree LGA is projected to remain the same.

Implications Sub-catchments that are characterised by a combination of relatively high total population, population density, annual growth rates and projections may be considered to be under intense population pressure. The following 3 of the 27 sub-catchments in the Catchment display these characteristics: Wingecarribee River, Nattai River and Werriberri Creek. These sub-catchments either fall within the Special Areas or are identified as a priority sub- catchment. Any growth in these sub-catchments will inevitably exert pressure on existing urban areas and their infrastructure, as well as biodiversity, native vegetation, green spaces and rural and resource lands. A number of regional strategies, devised by DoP, are currently in place to provide long-term sustainable planning frameworks that accommodate population growth. The Sydney– Canberra Corridor Regional Strategy applies to the LGAs of Wingecarribee, Goulburn Mulwaree, Upper Lachlan and Palerang (DoP 2008a). The South Coast Regional Strategy applies to the Shoalhaven LGA (DoP 2007). The regional strategies identify that the main challenges for future planning relate not only to the growing population but also to an aging population. The current and future migration of retirees, with a desire to live in rural areas, necessitates a change in the type of housing available – specifically, a shift towards smaller household occupancy rates. The regional strategies set clear land use plans, which balance the demands for this type of future growth with the need to protect and enhance environmental values. LGAs are currently required to consider and be consistent with the policies and actions in the regional strategies when preparing their LEPs. A number of positive environment outcomes have resulted from the changing demographic in the Catchment area. According to surveys conducted by the SCA (2007c), the permanent residents in the Catchment areas place a high value on healthy waterways and have a willingness to manage their land in ways that would improve water quality as long as their social and economic wellbeing is maintained. Landscape managers from the HNCMA have also observed an increased interest in sustainable land practices. This interest has been reflected in the demand for local community programs and, significantly, in the transition from intensively farmed land to hobby farms in some parts of the Catchment. The Auditor recognises the benefits of existing educational programs and the need for these programs to continue. 3.5 Community attitudes, aspirations and engagement

Background Community attitudes, aspirations and engagements can be measured by the number of community natural resource management (NRM) organisations, and by the number of landholders actively engaged in improvement works in the Catchment (NOW, 2009). These are new indicators reflecting the protection of the natural values and the health and productivity of a catchment. These are achieved through strategic planning, partnerships and funding of natural resource management projects on public and private land to address issues deemed to be of critical importance. The key partnerships include state agencies, local government, landcare and bushcare groups, Aboriginal groups, landholders, primary producers, the community and industry. This indicator is also a direct measurement of the CMA’s ability to engage the community in key natural resource management issues facing their catchments. CMAs are the prime mechanism for the integrated delivery of incentive programs funded by the NSW and

42 2010 Audit of the Sydney Drinking Water Catchment Australian governments to implement natural resource management across the State. The specific functions of CMAs as described in Section 15 of the Catchment Management Authorities Act 2003 are to: • develop Catchment Action Plans (CAP) and give effect to any such approved plans through annual implementation programs • provide loans, grants, subsidies or other financial assistance for catchment activities • enter contracts or do any work for the purpose of catchment activities • assist landholders to achieve the objectives of the CAP • provide educational and training courses and materials in connection with NRM. Community activities of the SCA, HNCMA; SRCMA and the Sydney Metropolitan Catchment Management Authority (SMCMA) were considered for the current audit.

Findings

Sydney Catchment Authority The SCA provides a wide range of community programs in the Catchment. The Catchment Protection Scheme (CPS) is a joint initiative between the SCA, the HNCMA and SRCMA and landowners. It provides incentives for landholders to treat active gully erosion, streambed lowering, and associated streambank erosion. The SCA and CMAs are using existing maps of gully erosion to track the effectiveness of erosion controls. Major achievements from the CPS during the current audit period included: • In 2007–2009 the CPS supported 72 landowners treating over 4596 hectares of erosion, protecting approximately 1513 hectares of upstream catchment area. It allowed over 37 kilometres of streambank to be stabilized and 111.5 kilometres of riparian land to be fenced. • In 2008–2009 the SCA contributed $550,000 to the CPS. CMAs contributed cash and in- kind contributions of $1.096 million, bringing the scheme’s expenditure to $1.646 million. • In 2009–2010 the SCA continued to work with the CMAs and landholders to repair major erosion sites. Other important contributions to community engagement include: • The SCA visitor centre and outdoor facilities at Warragamba Dam engages and informs the community about the importance of water, the water supply system and catchment management. • The SCA hosts excursions for students at Warragamba Dam to provide and support education about the water supply, catchment issues, and relevant science issues • In partnership with the Department of Education and Training, teachers’ associations, and Sydney Water, the SCA produces HSC level science curriculum linked resources. • A new education space at the visitor centre delivers education activities for students and teachers about water quality, water supply and catchments. • The SCA convenes a local government reference panel to provide a forum for catchment councils to meet, share ideas, and provide input and feedback about SCA catchment activities and water quality issues. • The SCA provided equipment, training and support to 34 Streamwatch volunteer groups to monitor water quality at specific registered sites throughout the catchment. • The SCA provided catchment protection and improvement grants each year to support small community-based projects. • The SCA coordinated CleanOut, a free annual household chemical collection program to prevent hazardous household chemicals from being dumped in the catchments and seeping into waterways. The program is a joint effort between the SCA, DECCW, and local councils to support the community.

Chapter 3 – Land Use and Human Settlements 43 Hawkesbury–Nepean Catchment Management Authority The number and types of organisations actively engaged in improvement works in the Catchment are provided in the appendices of the Hawkesbury–Nepean Catchment Action Plan and the HNCMA Annual Reports. A summary of landholder partnerships is provided below. The number of landholder partnerships over the period 2007–2009 is shown in Figure 3.5.1. The spread of investment across 13 key state targets is summarised in Figure 3.5.2.

2007–2008 Landholders and NRM group highlights in the Catchment • 302 landholders were funded • 120 Landcare and environmental groups were supported • 100 plus landcarers attended to the inaugural Hawkesbury–Nepean Landcare Forum • 2600 plus landcarers were recognised for their efforts • 68 groups were covered by HNCMA insurance • Recruitment of over 3,000 Landcare members • 36 events and field days were held attracting approximately 860 participants • $2 million of work carried out by volunteers (over 68,000 volunteer hours) • $1 million in additional funding gained for landcare activities in the catchment • Publication of a major report Healing our Catchment – a Report on Landcare in the Hawkesbury–Nepean

2008–2009 Landholders and NRM group highlights in the Catchment • $705,000 invested in supporting environmental and community groups through six Community Support Officers • 161 new partnership projects with landholders • 884 landholders attended farm management training • 125 landcare groups were supported: including 33 new groups while another 18 groups have dispersed after completing projects • 72 groups covered by HNCMA insurance • 1100 plus participants attend second bi-annual Hawkesbury–Nepean Landcare Forum • 2700 plus Landcare members carrying out $2.15 million of work • 149 training sessions, workshops and seminars were held • 36 field days (information/awareness) and 26 workshops were held • 52 Landcare group meetings were assisted • HNCMA provides technical assistance to landholders and community groups in The River Restoration Project to restore and protect creeks and rivers. Achievements include: - 56.1 kilometres of riverbank rehabilitated (a total area of 489 hectares) - 70 individual landholder projects funded - 50 kilometres of fencing was undertaken to protect river and creek banks and a total of 35 off-river stock watering points were installed - 11.4 kilometres of river and creek banks were revegetated with 22,990 native plants • The HNCMA commenced a joint project at Arthursleigh, the Sydney University’s 6260- hectare property near Marulan. The project is a major partnership between the HNCMA, Greening Australia, DECCW, corporate sponsors and the University of Sydney. Its aim is to: - protect 1260 hectares of bushland through 12 kilometres of fencing - restore 10.5 kilometres of the banks of the Wollondilly River and fence 24 kilometres of the riverine corridor. The HNCMA 2009–10 Annual Report was not available at the time of publishing this report.

44 2010 Audit of the Sydney Drinking Water Catchment

Figure 3.5.1: Number of landholder partnerships for years 2004 to 2009 Source: HNCMA 2009

Figure 3.5.2: Financial component (item 13) of the HNCMA budget for community building Source: HNCMA 2009

Chapter 3 – Land Use and Human Settlements 45 Southern Rivers Catchment Management Authority

2007–2008 Landholders and NRM group highlights in the Catchment • 2 million invested in community and partnership programs • 361 community groups supported • 568 landholders were supported • 2000 rural landholders, Landcare groups, NRM stakeholders and Aboriginal people were surveyed, providing baseline information on the effectiveness of the SRCMA’s engagement and support to individuals and groups • 68 funding applications were supported • 20 funding applications were successful • 27 community and partnership training events were held • 28 community and partnership training materials were developed • 147 community and partnership non-training forums were held • 234 community and partnership non-training products were developed • 59 community and partnership media articles were released • 13 Aboriginal land councils were supported • 15 Aboriginal community projects were supported

2008–2009 Landholders and NRM group highlights in the Catchment • $1.4 million invested in community and partnership programs • 406 community groups supported • 915 landholders or individuals supported • 61 community funding applications supported • 28 community funding applications were successful • 105 community and partnership training sessions and seminars events were held • 13 community workbooks, course notes, learning materials were developed • 148 community and partnership demonstration, field days and study tours were held • 584 community and partnership brochures, newsletters, fact sheets and posters were developed • 77 media community opportunities resulting in newspaper, radio and TV articles • 13 Aboriginal land councils were supported • 18 Aboriginal community projects were supported

Sydney Metropolitan Catchment Management Authority As the two Catchment areas which overlap with the SMCMA areas are regarded as being of high natural quality, the SMCMA is focusing its investment in resources in other more degraded areas (SMCMA Submission 2010).The SMCMA does not currently have any specific programs or actions in the two catchments areas, Woronora or Prospect Reservoir, that overlap with the SMCMA areas.

Implications In order for catchment management programs and actions to be effective in the longer term, they require the support of the community that lives within the Catchment. The level of engagement of the community and landholders in catchment management programs and actions during the current audit period was high. It is important that the community continue to be engaged in these projects through ongoing communication, interaction and involvement.

46 2010 Audit of the Sydney Drinking Water Catchment Chapter 4 Biodiversity and Habitats

4.1 Macroinvertebrates

Background Aquatic ecology in the Catchment is affected by natural flows, flow regulation and modification, water quality, changes due to catchment disturbance and runoff, the discharge of treated effluent and land use. The most well-developed and widespread of the available biological indicators of stream health in NSW is macroinvertebrates collected by the methods of either Chessman (1995) or Turak et al. (2000, 2004). Macroinvertebrates are commonly used throughout the world to assess the environmental health of a river, stream, creek or wetland because they are sensitive to changes in water quality and flow regimes and allow detection of environmental impacts for some time after the event has occurred. They are easily collected, abundant, diverse, readily seen with the naked eye and the knowledge of taxonomy is advanced and well documented. The widely accepted and supported AusRivAs (Australian River Assessment System) methodology utilises site-specific predictions of the macroinvertebrate assemblage expected to be present at a site in the absence of environmental stressors. The expected assemblages of macroinvertebrates from sites with similar physical and chemical characteristics (characteristics that are not influenced by human activities, e.g. altitude) are compared to the macroinvertebrate assemblage observed during sampling. The ratio of observed to expected macroinvertebrates can vary from zero, when none of the expected macroinvertebrates are collected at a site, to one or greater, when all or more of the expected macroinvertebrates are collected. The observed over expected ratios (scores) are placed in bands thus permitting an assessment of the environmental health of the river for that site. Computer models calculate a band for each site based on the physical and chemical properties of the site, the time of collection (Spring or Autumn), the habitat (Edge or Riffle) and the macroinvertebrate families collected (Table 4.1.1 and Table 4.1.2). Table 4.1.1: AUSRIVAS bands for Spring, Edge habitat

Source: SCA MMP 2009 Report

Chapter 4 – Biodiversity and Habitats 47 Table 4.1.2: AUSRIVAS bands for Spring, Riffle habitat

Source: SCA MMP 2009 Report The SCA is required by its Operating Licence to report annually on macroinvertebrate assemblages in Catchment waterways. DECCW is responsible for the macroinvertebrate component of the Monitoring, Evaluation and Reporting (MER) program for NSW rivers and streams. Both organisations sample macroinvertebrates throughout the Catchment.

Findings Over the last decade, a total of 456 sites in the Catchment were identified as having been sampled and an AusRivAS assessment made for macroinvertebrates (see Table 4.1.3). Data specific to the current audit period are tabulated in the sub-catchment summary section (Appendix C). Macroinvertebrate data were primarily sourced from the SCA, DECCW and Delta Electricity monitoring programs. This represents a significant investment in ecosystem health monitoring by these organisations. It is highly likely that there are other macroinvertebrate monitoring sites which have not been captured in this summary and further work is required to provide a comprehensive summary of all macroinvertebrate sampling that has occurred in the Catchment. Of the 456 sites identified as having been sampled for macroinvertebrates over the last decade, almost half (48.9%) were found to be in similar to reference (band A) or richer than reference (band X) condition. Fifty-one sites (11%) were found to be in a severely impaired (band C) condition and three sites (0.7%) in an extremely impaired (band D) condition. This indicates that the macroinvertebrate health throughout the Catchment is generally good, but that there are some areas that are poor in terms of macroinvertebrate health. On a sub-catchment basis, the Upper Coxs River sub-catchment had the highest percentage of sites (52.7%) in the severely impaired (band C) or extremely impaired (band D) condition. This was followed by the Boro Creek (28.6%), Woronora River (23.5%), Wollondilly River (21.7%) and Reedy Creek (21.4%) sub-catchments. The Woronora River result needs to be treated with caution since many monitoring sites were below the dam. There is also a high percentage of bedrock in the Woronora River catchment streams which may contribute to reduced macroinvertebrate diversity in this sub-catchment.

48 2010 Audit of the Sydney Drinking Water Catchment Table 4.1.3: Sub-catchment summary of macroinvertebrate AusRivAS rankings

Number X A B C D OEM A&X C&D Sub-catchment of sites (%) (%) (%) (%) (%) (%) (%) (%) Upper Coxs River 38 0 10.5 26.3 47.4 5.3 10.5 10.5 52.7 Boro Creek 7 0 14.3 57.1 28.6 0 0 14.3 28.6 Woronora River 17 5.9 11.8 58.8 23.5 0 0 17.7 23.5 Wollondilly River 23 4.3 30.4 39.1 21.7 0 4.3 34.7 21.7 Reedy Creek 14 0 50 28.6 21.4 0 0 50 21.4 Lower Coxs River 18 11.1 50 22.2 16.7 0 0 61.1 16.7 Wingecarribee River 13 0 53.8 30.8 15.4 0 0 53.8 15.4 Werriberri Creek 8 0 37.5 50 12.5 0 0 37.5 12.5 Mulwaree River 8 0 62.5 25 0 12.5 0 62.5 12.5 Kowmung River 22 13.6 50 27.3 9.1 0 0 63.6 9.1 Upper Wollondilly River 11 9.1 27.3 54.6 9.1 0 0 36.4 9.1 Nerrimunga River 12 0 16.7 75 8.3 0 0 16.7 8.3 Braidwood Creek 12 8.3 33.3 50 8.3 0 0 41.6 8.3 Upper Nepean River 38 7.9 55.3 28.9 7.9 0 0 63.2 7.9 Bungonia Creek 13 0 69.2 23.1 7.7 0 0 69.2 7.7 Jerrabattgulla Creek 18 16.7 55.6 22.2 5.6 0 0 72.3 5.6 Upper Shoalhaven River 18 0 55.6 38.9 5.6 0 0 55.6 5.6 Mid Coxs River 57 3.5 35.1 57.9 3.5 0 0 38.6 3.5 Grose River 9 0 22.2 55.6 0 0 22.2 22.2 0 Lake Burragorang 7 0 28.6 71.4 0 0 0 28.6 0 Little River 7 0 42.9 57.1 0 0 0 42.9 0 Nattai River 14 0 42.9 50 0 0 7.1 42.9 0 Kangaroo River 19 10.5 73.7 15.8 0 0 0 84.2 0 Mid Shoalhaven River 19 5.3 84.2 10.5 0 0 0 89.5 0 Endrick River 5 20 20 60 0 0 0 40 0 Mongarlowe River 15 6.7 80 13.3 0 0 0 86.7 0 Back & Round Mountain Creek 14 7.1 64.3 28.6 0 0 0 71.4 0 Total 456 5.04 43.85 37.5 11.18 0.657 1.754 48.90 11.84

Note: X = richer than reference (band X); A = similar to reference (band A); B = significantly impaired (band B); C = severely impaired (band C); D = extremely impaired (band D); OEM = outside experience of model; A&X = band A and band X; C&D = band C and band D. The Mid Shoalhaven River had the highest percentage (89.5%) of sites in the similar to reference (band A) or richer than reference (band X) condition. This was followed by the Mongarlowe River (86.7% of sites) and Kangaroo River (84.2% of sites) sub-catchments. The spatial distributions of monitoring sites within a sub-catchment are illustrated in the sub- catchment summary section (Appendix C). Further information is also provided in this section for sub-catchment sites monitored more than a decade ago, which may provide additional information on macroinvertebrate health, albeit now somewhat out of date (depending on the changes that have occurred in the sub-catchment since the last date of sampling). For some sub-catchments, sampling sites are often clustered rather than being distributed evenly throughout the sub-catchment. In addition, since the majority of sites have not been selected randomly and the sample size for some sub-catchments is relatively small, inference from the percentages presented here to the entire sub-catchment need to be treated very cautiously.

Chapter 4 – Biodiversity and Habitats 49 A number of sites included in the above list have also been sampled over time, providing some opportunity to consider whether temporal changes have occurred at these sites (Figure 4.1.4). Unfortunately, since routine sampling for many sites only commenced in 2001, the time series of macroinvertebrate AusRivAS assessments remains relatively short. The majority of monitored sites returned reasonably consistent AusRivAS ratings over time. The exception was the Mulwaree River at Towers Weir site (E457). AusRivAs scores at E457 had historically fluctuated between band B (significantly impaired) and band A (similar to reference) condition, but since 2006, E457 has recorded two band C (severely impaired), one band A (similar to reference) and one band D (extremely impaired) rating. The latest AusRivAs rating at this site (2009) was band D (extremely impaired). Close attention needs to be paid to this site in the future to see if macroinvertebrate diversity improves or remains in the extremely impaired category. If it remains extremely impaired then a more detailed assessment of causal factors may need to be considered. Further details on how other individual sites have varied over time are discussed in the individual sub-catchment summary section (Appendix C). It is also noted that the spatial coverage of the SCA’s macroinvertebrate monitoring program across the Catchment has decreased over recent times. In 2007, 173 samples were collected in the Catchments. In 2009 this was down to 136. This decrease is likely to be the result of a review of the macroinvertebrate program (SKM 2009) which subsequently saw roaming sampling sites dropped from the program.

Implications The SCA, DECCW and other organisations (e.g. Delta Electricity) have invested considerable resources in the assessment of macroinvertebrate health throughout the Catchment. The results from this investment indicate that the macroinvertebrate health in the Catchment is generally good. There are however, some areas where instream macroinvertebrate health is in a severely impaired (band C) or extremely impaired (band D) condition. The Upper Coxs River sub-catchment is the most obvious example where there are a large number of sites that have received a band C or D rating. Areas where impaired assessments have been made are usually associated with sites with significant habitat modification (e.g. riparian clearing, erosion, instream simplification) or point source discharges. Sites downstream of dams also often had an impaired macroinvertebrate AusRivAS rating. The Auditor supports continued investment in macroinvertebrate health monitoring throughout the catchment as it is one of a very few standardised biological indicators that can be used to assess ecosystem health. Further knowledge will be gained as monitoring continues and additional sites are sampled in the future. Over the longer term, this will assist in a gradual increase in the knowledge base of ecosystem health throughout the Catchment. As discussed earlier: • The SCA is required by its Operating Licence to report annually on macroinvertebrate assemblages. • Delta Electricity is also required by its Operating Licence to sample macroinvertebrate assemblages. • DECCW is responsible for the macroinvertebrate component of the MER program for NSW rivers. There appears to be considerable potential for these programs to be integrated so that a wider coverage of macroinvertebrate sampling can be achieved in the Catchment. The Auditor believes the SCA, Delta Electricity and DECCW should explore ways to integrate their respective macroinvertebrate sampling programs so that they maximise the number and spread of sites (fixed and random) throughout the Catchment. Further, the data should be integrated into a consistent database and shared with other organisations (e.g. CMAs) working in the Catchment.

50 2010 Audit of the Sydney Drinking Water Catchment

Figure 4.1.4: Macroinvertebrate AusRivAs health rating in the Catchment for 2001–2009 A number of sites have now been shown to have macroinvertebrate assemblages indicating an impaired or degraded condition. Where instream habitat has been extensively modified and/or riparian zones cleared, this result is not surprising. Some sites, however, have impaired ratings without an obvious causal driver or appear to potentially be experiencing a decline in health. Follow-up monitoring at impacted sites with no obvious causal drivers for an impaired rating should be undertaken to confirm their impacted state. In addition to follow-up macroinvertebrate monitoring, the integration of the results of macroinvertebrate monitoring with other indicators of catchment health in the Catchment, such as water quality, fish and riparian zone monitoring, would be beneficial (see Section 6.5). This would help provide a more comprehensive and integrated assessment of Catchment health across a wider range of catchment health indicators. Such integration may also enable more focused management responses to identified changes in the condition of macroinvertebrate and other assemblages.

Recommendation 6: The SCA continue to undertake follow-up monitoring at macroinvertebrate monitoring locations that have scored an AusRivAs rating of significantly impaired, severely impaired or extremely impaired where there is no obvious driver for an impacted rating.

4.2 Fish

Background The abundance and diversity of many native fish and crustacean species has declined in most regions of Australia since European settlement. The natural range of about one-third of native inland-water fish has been significantly reduced. Continued pressures from habitat modification, introduced pests, pollution and harvesting continue to affect native fish species and fish communities. Fish populations in the Catchment are also likely to have been especially impacted by the modification of river flows and physical barriers caused by dams and weirs, the temperature of water released from dams, and competition with exotic fish species (DECC 2007a). Dams and weirs modify and disrupt natural flows of rivers and streams by collecting variable flows and then releasing constant or regulated water-flows downstream. The modification of flows can affect a wide range of aquatic organisms, including fish, potentially reducing the species diversity and increasing the success of introduced species (Gehrke and Harris 2001). Water released from dams is also often colder than downstream flow, especially if the dam has a bottom valve off-take. Cold water pollution can affect fish growth and survival and can potentially limit the distribution of fish within rivers to warmer areas (NSW Fisheries 2003). Dams, weirs, and many types of in-stream works also act as significant barriers to fish passage, reducing the abundance and diversity of fish throughout a river system (CRCFE 2000). Physical barriers prevent the upstream and downstream passage of migratory fish, and inhibit access of fish to other areas of rivers over shorter distances. This indicator remains highly relevant as a measure of ecosystem health, as fish interact on many trophic levels and are sensitive to many kinds of human disturbance. Fish are also considered useful for environmental assessments due to their mobility and longevity. The abundance of fish individuals and species can decrease in areas with degraded riparian vegetation and poor water quality (Growns et al. 1998). I&I Fisheries identified five key research projects for which data were collected within the Catchment area between 1 July 2007 and 30 June 2010. These were: i. Continuation of research into the distribution of the introduced redfin perch in the Wollondilly Catchment in August 2007.

Chapter 4 – Biodiversity and Habitats 51 ii. Research into the passage of fish through fishways, including research targeting the endangered Macquarie Perch – 2007 onwards; iii. A state-wide assessment of the diversity, distribution and abundance of fish in NSW rivers, as part of the NSW Government’s MER riverine program – November/December 2007; iv. Assessment of the fish community above and below Pheasants Nest weir April – June 2009. v. Assessment of the fish community in the Shoalhaven River catchment before and after construction of a fishway on Tallowa Dam – November 2009 onwards. All 5 projects were identified as continuing in some form after July 2010. In particular, the MER rivers program will involve regular sampling of sites in the medium- to long-term, with the next sampling round planned for October/November 2010.

Findings I&I Fisheries provided a detailed response on Fish sampling in the Catchment for the current audit period. The following sections largely repeat what I&I Fisheries provided in their submission. During the three years covered by the current audit, 67 sites within 16 SCA sub-catchments were sampled using a combination of electrofishing, unbaited traps and net sampling techniques. The sampling, following strict protocols, covered 41 water bodies from which a total of 5149 fish (representing 22 species) were captured. Fifteen species of fish were endemic to the Catchment, and seven species were introduced (Table 4.2.1). Direct comparisons of the catch data across sites are limited because the dataset contains a number of projects in which sampling effort varied considerably. Nonetheless, it is noteworthy that introduced freshwater fish species were captured in 15 of the 16 sub- catchments (94%; Table 4.2.2). The Endrick River sub-catchment was the only area in which introduced species were not caught (i.e. had only native species). Sampling in this sub- catchment, however, consisted of only one site and represented the lowest sampling effort of all sub-catchment areas (0.2% of total hours – compared to an average per catchment of 6.3% of total hours (range = 0.2-23%; median = 3.7%). This finding is in contrast to the previous audit for which 10 out of 28 sub-catchments (37%) had only endemic species. Introduced species were the only species captured in the Boro Creek and Kowmung River sub-catchments, while the Wollondilly River had the largest total catch of introduced species (114 of 509 fish caught, or 22%). Introduced species, which represented 10% of the total catch overall, can have large impacts on the endemic aquatic fauna. Introduced species often thrive in degraded habitats and hence may indicate that the Wollondilly River, in particular, is in poor ecological condition.

Table 4.2.1: Fish species recorded in the Catchment area by I&I Fisheries between 1 July 2007 and 30 June 2010

Family Scientific name Common name Status Anguillidae Anguilla australis Short finned eel Endemic Anguilla reinhardtii Long finned eel Endemic Cobitidae Misgurnus anguillicaudatus Oriental weatherloach Introduced Cyprinidae Carassius auratus Goldfish Introduced Cyprinus carpio Common carp Introduced Eleotridae Gobiomorphus australis Striped gudgeon Endemic Gobiomorphus coxii Cox's gudgeon Endemic Hypseleotris klunzingeri Western carp gudgeon Endemic Hypseleotris galii Firetail gudgeon Endemic Hypseleotris spp. Unidentified gudgeon Endemic

52 2010 Audit of the Sydney Drinking Water Catchment Family Scientific name Common name Status Philypnodon grandiceps Flathead gudgeon Endemic Philypnodon macrostomus* Dwarf flathead gudgeon Endemic Galaxiidae Galaxias olidus Mountain galaxias Endemic Percichthyidae Macquaria australasica** Macquarie perch Endemic Macquaria novemaculeata Australian bass Endemic Petromyzontidae Mordacia praecox Non-parasitic lamprey Endemic Percidae Perca fluviatilis Redfin perch Introduced Plotosidae Tandanus tandanus Freshwater catfish Endemic Poeciliidae Gambusia holbrooki Eastern gambusia Introduced Retropinnidae Retropinna semoni Australian smelt Endemic Salmonidae Oncorhynchus mykiss Rainbow trout Introduced Salmo trutta Brown trout Introduced * previously Philypnodon sp.1, **endangered. Source: I&I Fisheries

Table 4.2.2: Numbers of endemic and introduced fish species captured in the Catchment area by I&I Fisheries between 1 July 2007 and 30 June 2010 Sites Endemic Introduced Overall species Sub-catchment sampled species species richness*** Boro Creek 2 3 3 Bungonia Creek 5 8 3 11 Endrick River 1 3 3 Kangaroo River 8 7 3 10 Kowmung River 3 3 3 Lake Burragorang 3 10 3 13 Little River 4 4 2 6 Lower Coxs River 1 4 1 5 Mid Coxs River 4 2 3 5 Mongarlowe River 1 4 3 7 Mulwaree River 1 2 1 3 Upper Nepean River 17 11 2 13 Upper Shoalhaven River 1 1 1 2 Wingecarribee River 3 2 3 5 Wollondilly River 11 6 4 10 Woronora River 2 2 1 3 Total 67 14 15

Source: I&I Fisheries *** Combined total of Endemic and Introduced species Low species diversity (3 species or less) was found in six sub-catchments, with the Upper Shoalhaven having only 2 species – one introduced and one endemic (Table 4.2.2).

Chapter 4 – Biodiversity and Habitats 53 Tallowa Dam Sampling was undertaken twice at nine sites, in late 2009 and early 2010, within the Bungonia Creek, Kangaroo River and Mongarlowe River sub-catchments as part of the assessment of the fishway on Tallowa Dam. Endemic species captured were the Australian bass, Australian smelt, long-finned eel, carp gudgeons, Cox's gudgeon, dwarf flathead gudgeon, flathead gudgeon, mountain galaxias and striped gudgeon. Three introduced species were also captured – common carp, goldfish and gambusia, comprising 3.4% of total catch. A total of 2481 fish were caught at these sites in the Upper Shoalhaven with the catch dominated by Australian smelt (74% of the catch). Catch data at these sites are also considered below with respect to long-term sampling within the Catchment area.

Pheasants Nest Weir Sampling of the fish community around the Pheasants Nest Weir on the Upper Nepean river (15 sites sampled in mid 2009) caught the endemic Australian smelt, Cox's gudgeon, dwarf flathead gudgeon, flathead gudgeon, short and long-finned eels, non-parasitic lamprey, Mountain galaxias, and the introduced eastern gambusia and oriental weatherloach. A total of 23 Macquarie perch were also sampled – 6 in the Nepean River, 6 in Cordeaux creek, and 11 in Little River. Australian smelt were the most abundant species sampled, comprising 156 of the 329 fish caught, while gambusia were the most prevalent introduced species comprising 10.6% of the total catch.

Macquarie perch The Macquarie perch is listed as an endangered species under the NSW Fisheries Management Act 1994 and during this audit period 37 fish were recorded from 12 sites, within 7 water bodies and 4 sub-catchments: the Mongarlowe River, Little River, Upper Nepean and Mid Coxs River.

Redfin perch The Redfin perch is an introduced species that was first detected in the Wollondilly River in May 2006 (see DECC 2007a, p 92). It is implicated in the decline of Australian freshwater fish including the endangered Macquarie perch. To further investigate its spread, I&I Fisheries sampled 14 sites in May–June 2007. Redfin perch (7 fish in total) were found at 4 of these sites – all in the Wollondilly and Mulwaree River sub-catchments. This is one more site than reported in the previous audit – this site was on the Paddy’s River, 20 km downstream of previous records.

Trend Analysis of long-term catch data throughout the Catchment area is restricted due to infrequent regular sampling. A total of 210 sites, within 25 sub-catchments, were sampled from 1993 onwards, but only 9 sites (in 3 sub-catchments) have been sampled on 5 occasions during this 17-year period. These sites were sampled in the period 1998–2010 around Tallowa Dam to monitor fish assemblages before and after fishway construction. Twenty fish species have been recorded at these sites during this time, 16 of which are endemic (Hypseleotris spp., Gobiomorphus spp, Philypnodon spp.), eels, smelt, catfish and Macquarie perch) and 4 introduced (carp, goldfish, gambusia and brown trout).

54 2010 Audit of the Sydney Drinking Water Catchment Table 4.2.3: Numbers of endemic and introduced fish species captured from repeated site sampling at 9 sites around Tallowa Dam in 1998–2010

Year 1998 1999 2005 2009 2010 Endemic 12 15 9 9 9 Introduced 4 2 2 3 3 Total species richness 16 17 11 12 12

Source: I&I Fisheries

Smelt contributed the highest catch with an average of 65% of each year’s total catch (range: 45–84%), while flathead gudgeons comprised an average of 24% of each year’s total catch (range: 10–34%). Seven endangered Macquarie perch have been captured, but only from the Mongarlowe River sub-catchment – 5 in 1998 and 2 in 1999. No Macquarie perch have been captured in the ‘after’ sampling period. Species richness has varied from 11 to 17 species (Table 4.2.3), with a consistently low number (9) of native species encountered during the ‘after’ sampling period.

Barriers to fish movement and migration Dams and weirs affect the natural flow of water in rivers, restrict the migration of fish and limit their habitat. The NSW Government is committed to improving environmental flows and fish passage in the Hawkesbury–Nepean River, which improves the health of the river (OHN and SCA undated). Thirteen weirs were built on the Hawkesbury–Nepean River over the last 100 years. Some of the weirs have fish passages which only work across a small range of river flows and generally suit large fish. New fishways will be installed at 10 weirs using vertical slot fishways (OHN and SCA undated). These new fishways will allow fish to pass during a wider range of flows and help smaller native fish to migrate along the river. The construction of many of these fishways has been completed during the current audit period (e.g. See Figure 4.2.1 below). In 2009 the SCA constructed a fish ‘lift’ at Tallowa Dam to allow fish to move upstream and downstream of the dam structure. This fish ‘lift’ was inspected by the audit team during the current audit (see Figure 4.2.1). The mechanical fish ‘lift’ works by transporting fish up and over the dam wall. Fish are drawn to the fish ‘lift’ by water moving at its entrance (the ‘attraction chamber’). Once in the chamber they are guided through a fish trap into a metal container called the ‘hopper’. After a short time, the hopper is lifted out of the water and winched over the dam wall. It is then lowered to the lake on the other side and fish are released from the hopper. Variable environmental flow releases from the dam also increase the time when enough water flows over the dam wall for fish to safely migrate downstream. When fish go through the spillway gate they slide down the dam wall. A smooth coating has been added to the dam wall directly below the gate to make it safer for fish. A deep pool has been created at the foot of the dam wall to help protect the fish when they land downstream. From here fish can make their way further downstream and can access the estuary and mouth of the Shoalhaven River3 .

3 The Shoalhaven River actually now joins and flows out of the Crookhaven River mouth.

Chapter 4 – Biodiversity and Habitats 55

Figure 4.2.1: Fishway at Pheasants Nest (left) and lower section (rails) of Fish ‘lift’ at Tallowa Dam (right) Palerang Council’s submission (2010) also identified that a fish-friendly crossing was constructed on the Mongarlowe River at Northangera Road (Burke’s Crossing) as part of the Bringing back the fish program (I&I 2009). This resulted in improved fish access, including the threatened Macquarie Perch, to 43km of upstream habitat.

Implications I&I Fisheries undertake fish monitoring for the MER rivers program which involves regular sampling of sites in the medium- to long-term. A number of fish monitoring programs are underway to assess the effectiveness of various fishways (Nepean Weirs program) and the fish ‘lift’ at Tallowa Dam. These programs will require a longer period of time before their effectiveness can be adequately assessed. Other than the studies mentioned above, fish monitoring programs throughout the Catchment are relatively rare. Obtaining adequate long- term fish data to undertake an assessment of trend is therefore very difficult. The integration of fish monitoring with other indicators of catchment health in the Catchment, such as water quality, macroinvertebrates and riparian zone monitoring, would be beneficial. This would help provide a more comprehensive and integrated assessment of Catchment health across a wider range of catchment health indicators. Such integration may also enable more focused management responses to identified changes in the condition of fish and other assemblages. The SCA and I&I Fisheries should investigate the potential for integrating their fish monitoring into a broader catchment-wide ecosystem monitoring program (see further discussion of this issue in Section 6.5).

4.3 Riparian vegetation

Background Riparian zones typically consist of vegetated corridors adjacent to stream channels where the vegetation is influenced by water. These areas can be effective barriers to pollution from land based activities, including agriculture and urbanisation. The riparian zone also contributes to ecosystem health by providing shade, stabilising banks, minimising erosion, limiting downstream flooding, supporting fisheries, taking up and storing nutrients and contaminants and by providing habitat for a wide range of species (DECC 2007a). Riparian zones are often the most fertile part of the landscape and are subject to many pressures from land management practice, land use change and human activities (DECC 2007a). The primary pressures on riparian vegetation are removal of riparian vegetation; introduced plant species (e.g. willows – Salix spp.); and trampling and grazing by stock.

56 2010 Audit of the Sydney Drinking Water Catchment Riparian zone degradation resulting from the alteration of natural water flow regimes of rivers, streams, floodplains and wetlands has been listed as key threatening processes in NSW under the Threatened Species Conservation Act 1995 (DECC 2008). Native fish also often rely on riparian vegetation for shelter and habitat. In November 2001, the degradation of native riparian vegetation along NSW water courses was also listed as a key threatening process under the Fisheries Management Act 1994 (DPI 2008). Grazing is the largest private land use in the Catchment and is an important pressure on riparian zones, particularly where animals (e.g. cattle and sheep) have direct access to riparian areas. Grazing adjacent to watercourses can lead to a reduction in vegetation, promote stream bank erosion and can contribute to water pollution (e.g. sediment, nutrients, pathogens etc). The current audit focused on the extent and condition of riparian vegetation in the Catchment. The area of vegetation cleared in the riparian zone during the current audit period was also considered.

Findings The SCA estimated there were approximately 110,000 kilometres of river length with associated riparian land in the catchments (SCA 2009a). There was 81,125 hectares of riparian zone in the Catchment of which native vegetation covered 54,787 hectares (67.5%) and 23,806 hectares was pasture (SCA 2003). The SCA estimated that 38,753 km (35% of stream length) of watercourses in the Catchment were currently being, or had the potential to be, accessed by stock. This estimate has reduced slightly since 2005, when 38 per cent of the riparian zone in the Catchment was reported as being accessible to stock.

Grants, incentives and the Healthy Catchments Program The SCA has a number of programs aimed at addressing riparian zone management. Through the Riparian Management Assistance program, the SCA has increased the awareness of controlled grazing in order to protect water quality and riparian vegetation health in areas adjacent to watercourses. This program provided financial and practical assistance to landowners to protect riparian land through fencing initiatives and by providing alternative stock watering points. Remediation programs implemented under the Catchment Protection Scheme also aimed to control severe gully erosion and streambank erosion in riparian areas. Over the course of the audit period, the SCA has provided grants to landowners who manage land adjacent to creeks and waterways in order to control water pollution in grazed areas. SCA grants have helped fund graziers to fence 70.3 kilometres of riparian land, provide alternative watering points, repair minor erosion, and revegetate riparian areas in priority areas. This grants initiative aimed to have 40 percent of the grazed riparian areas addressed to reduce erosion and pathogen levels in 18 priority catchment rivers and streams (SCA 2010b). A future priority for the SCA was delivering targeted education and training to landowners for sustainable grazing practices in priority drainage unit areas (SCA 2009). The SCA’s Healthy Catchments Program identified several sub-catchments and drainage units which were a focus for riparian initiatives in the catchment. As part of the Healthy Catchments Program the SCA has provided grants to landowners to better manage riparian areas with specific action on at least 20 kilometres of riparian area in gullies streams and creeks (SCA 2010a).

Riparian Connectivity Index and Riparian Vegetation Index The SCA have developed a Riparian Connectivity Index (RCI) and a Riparian Vegetation Index (RVI) to determine the connectivity of riparian vegetation and the proportion of standing vegetation in riparian zones in the Catchment. The RVI index was derived from 2006 Landsat imagery across the Catchment, however, at this level of resolution there is

Chapter 4 – Biodiversity and Habitats 57 currently no discrimination between native and exotic species. Based on this index, riparian zones in national parks and Special Areas in the Catchment have a good proportion of standing vegetation, while the Mulwaree River, Upper Wollondilly River, Braidwood Creek and Reedy Creek sub-catchments all have little or no standing vegetation cover along the riparian zone (Figure 4.3.1). The SCA have also identified 19 drainage units within 7 sub- catchments (Kangaroo River, Bungonia Creek, Wollondilly River, Wingecarribee River, Upper Nepean River, Mid Coxs River and Upper Werriberri Creek) that are a potential risk to water quality (Figure 4.3.1). Areas surrounding these drainage units have little or no vegetation and have poor connectivity. The RVI is currently used to prioritise assessment of sites for the Riparian Management and Assistance Program.

Riparian zone management

Sydney Catchment Authority The SCA’s focus for riparian vegetation during the current audit period was on the: • improvement of connectivity of protected riparian zones through projects in Kangaroo Valley and Brogers Creek (2007–2008) • expansion of the Riparian Management Assistance Program from 1 July 2008 to include an additional six stream catchments within the Upper Nepean, Wingecarribee and Kangaroo River catchments • improvement in the ecological integrity of waterways that connect and influence SCA Special Areas through special projects, including the removal of willows and woody weeds from riparian areas along the Coxs River (2007–2008) • ongoing development of the CDSS, enabling access of new data on riparian vegetation to enhance the prioritisation of works undertaken by the Riparian Management Assistance Program • implementation of the Riparian Grants Evaluation and Monitoring (GEM) program by the SCA, HNCMA and SRCMA to measure the condition of a project site before and after SCA-funded works under MER – this includes evaluation of projects implemented to manage grazing stock in riparian lands • development of a quantitative grazing evaluation modelling tool by the SCA to evaluate changes in pollution risk associated with altered management practices on grazing land and riparian zones of perennial streams (stock rotation/exclusion, riparian revegetation) • Riparian Management Assistance program, which funded about 40,000 native plants for assisted regeneration between 2006 and 2010. The SCA has also funded a range of collaborations with universities and cooperative research centres.

58 2010 Audit of the Sydney Drinking Water Catchment

Figure 4.3.1: The 2006 Riparian Vegetation Index (RVI) for selected sub-catchments and drainage areas within the Catchment Source: Data from SCA 2006

Chapter 4 – Biodiversity and Habitats 59 Hawkesbury–Nepean Catchment Management Authority Under the Catchment Protection Scheme (CPS), the HNCMA in partnership with the SCA fenced and protected 359.1 hectares of riparian zone and gullies. This included treatment of 95 kilometres of gully and riparian zone. Grazing pressure has been reduced in many of these areas by fencing to increase stream bank stability and water quality. In addition to the works undertaken through the CPS, the HNCMA has implemented a number of riparian protection and enhancement projects as a result of priorities identified in the Hawkesbury Nepean River Health Strategy. This Strategy is a practical tool for managing and improving the health of the waterways in the Catchment (www.hn.cma.nsw.gov.au/topics/2201.html), and provides an understanding of the values, threats and issues affecting 255 river reaches and 3600 kilometres of waterways. The Strategy helps identify priorities for the CMA's on ground investment in river health to ensure environmental outcomes are maximised. The strategy is linked directly to the CMA's Catchment Action Plan which informs the CMA's work for the next 10 years. Overall, the HNCMA undertook 264 riparian protection and enhancements projects during the audit period. Those listed below provide examples of the types of projects: • riparian works in 2007–2008 on Arthursleigh Farm, Brayton Road, Marulan, where 20.5 hectares of severely eroded riparian land was fenced and revegetated • riparian fencing works along an unnamed tributary of the Tarlo River to reduce sediment transportation into the Tarlo River • a Willow (Salix cinerea) Removal Project • planting of 76,831 trees along gullies and riverbanks (extended drought conditions continued to affect seedling establishment during the audit).

Southern Rivers Catchment Management Authority During the current audit period, the SRCMA in partnership with the SCA undertook a variety of riparian works to protect native riparian vegetation under the CPS. CPS projects undertaken by SRCMA aimed to protect the Upper Shoalhaven and Kangaroo Valley water supply catchments against the effects of erosion and sedimentation. Programs undertaken by the SRCMA included: • 381 hectares and 2.2 kilometres of river and creek protected or enhanced by works in 2007–2008, including fencing, revegetation, and establishment of stream bank erosion control works • vegetation plantings during Spring 2007 and Autumn 2008 • 63.1 hectares of native riparian vegetation protected during 2008–2009 using fencing • 7.74 kilometres of stream bank length of riparian vegetation was also protected. Vegetation planting undertaken as part of CPS projects included 0.5 hectares of stream bank length revegetated; 0.13 hectares planted to native riparian vegetation; and 3.78 kilometres of stream bed stabilised to improve riparian health. Project activities also occurred on 5 properties under the SRCMA Riparian Partnerships Program focusing on fencing, weed control and revegetation in riparian areas with in kind contributions from landowners and support from the Natural Heritage Trust. These projects ensured that opportunities were available to landowners interested in carrying out riparian rehabilitation works to improve catchment water quality. In 2008–2009, a variety of project activities were also undertaken by SRCMA on 9 private properties as part of the Southern Riparian Partnerships Program to address significant riparian and in-stream degradation in the Upper Shoalhaven region. Shoalhaven Landcare in partnership with Shoalhaven City Council and the Kangaroo Valley Environment Group also undertook several weed control projects (privet and Madeira vine) in the Kangaroo Valley.

60 2010 Audit of the Sydney Drinking Water Catchment In 2009, the SRCMA and the Australian Government successfully concluded the three-year Shoalhaven Broom Control Project. This project managed riparian infestation of approximately 300 acres of Scotch Broom and Blackberry including the purchase of fencing materials to protect 15 kilometres of river bank and revegetation works on 45 acres of riparian land. A new bio-control agent, the Broom Gall Mite, was released during the 2010 audit period in an attempt to control Scotch Broom in the Upper Shoalhaven valley. This was a joint program by the SRCMA in partnership with the Department of Primary Industries (DPI, Victoria). Ongoing monitoring will be undertaken by SRCMA to determine the success of the Broom Gall Mite for the management of weeds in riparian areas (SCA 2009d Media Release) A summary of riparian works undertaken by the SRCMA in the Catchment during the 2010 Audit period is presented in Table 4.3.1

Table 4.3.1 Summary of riparian remediation works undertaken by the SRCMA

GIS/Land Catchment Management Protection Database Scheme Data source (LMD) reports Total Riparian native vegetation protected by fencing (ha) 33.86 76.42 110.28 Streambank length of riparian vegetation protected (km) 19.22 19.22 Riparian native vegetation enhanced / rehabilitated (ha)a 113.74 13.51 127.25 Streambank length of riparian vegetation enhanced /rehabilitated (km)a 4.21 4.21 Area planted to riparian native species (ha)a 15.76 15.76 Area of planted vegetation that are local – riparian (ha) 261.7 12.83 274.53 Streambank length of riparian native vegetation planted to riparian native species (km) 10.31 10.31 Source: SRCMA (2010) Note: Figures derived from Catchment Protection Scheme reporting and from spatial analysis of ArcGIS and the Land Management Database (LMD). a Reported figures are for 2009–10 only.

Local councils During the 2010 audit period, the Wollondilly Council, with the assistance of Greencorp Teams and the SCA undertook weed removal works and creek vegetation assessments within the Werriberri Creek sub-catchment. Weeds such as privet were removed along a two kilometre stretch of Werriberri Creek adjacent to Dudley Chesham Oval at The Oaks, resulting in a reduction of weed coverage within this reach to 20% (down from approximately 80%). This improvement in riparian health will be maintained through ongoing nursery plantings to be undertaken by Wollondilly Council along the riparian zone. The Wingecarribee and Wollondilly sub-catchments have only moderate standing vegetation cover along their riparian zones. In efforts to improve the condition and health of waterways the Wingecarribee Council is preparing a new LEP which identifies regional biodiversity corridors and riparian zones required for protection. Riparian zone vegetation restoration programs are also undertaken by Wingecarribee Council. The Goulburn Mulwaree Council has finalised the LEP 2009 which sets out to protect and enhance watercourses, riparian habitats, wetlands and water quality within the Goulburn Mulwaree catchments.

Chapter 4 – Biodiversity and Habitats 61 Implications There are many riparian areas in the Catchment with good proportions of standing and native vegetation cover, particularly in the Special Areas and national parks. However, there are also riparian zones in the Catchment that are under a variety of pressures as a result of little to no standing vegetation cover, large areas of pasture, stock access, and/or the presence of exotic species. These conditions can threaten ecosystem health and contribute to poor water quality. Healthy riparian zones assist in maintaining the health of rivers and streams in the Catchment, acting as part of the multiple ‘natural’ barriers that protect drinking water quality (DECC 2007a). Riparian zones are particularly important for water quality in areas where the adjacent land is agricultural or urban development. In particular, the Mulwaree River, Upper Wollondilly River, Braidwood Creek and Reedy Creek sub-catchments have little or no standing vegetation cover in their riparian zones. Water quality and ecosystem health remain at risk of further deterioration in these sub-catchments. Weed removal along riparian zones, such as willow elimination, can also cause disturbance in the riparian zone and can lead to erosion and water quality impacts. Weed management in the riparian zone needs to be undertaken with care. The SCA, CMAs and councils all have programs which involve a range of on-ground works to protect and rehabilitate riparian zones. All these programs are likely to contribute to an overall improvement in the health of the riparian zone which will in turn provide improved protection of water quality in the streams. The implementation of the riparian GEM program by the SCA and CMAs should help ensure that the intermediate outcomes of riparian projects are accurately evaluated and monitored before and after project works are implemented. This information will hopefully demonstrate the progress made towards achieving better water quality outcomes over time. The Auditor notes that continued and improved alignment, coordination and liaison between organisations will improve the biophysical outcomes of the programs/works at the landscape level. Targeted on-ground rehabilitation works still need to be continued in the Mulwaree River, Upper Wollondilly River, Braidwood Creek and Reedy Creek sub-catchments, as these are the sub-catchments with the least standing vegetation in their riparian zone (SCA 2006; DECC 2007a). Without long-term remediation work, it is likely that these areas will continue to ‘leak’ sediments and nutrients into the creeks, streams and rivers for many years to come. While records are maintained by relevant agencies and organisations about individual programs for riparian management, there does not appear to be a systematic use of measures to record the extent of this work. The Auditor is therefore not able to report on the exact location of riparian restoration and rehabilitation works throughout the Catchment. This information should be systematically collected. Overall integration of riparian vegetation monitoring with other (biological and water quality) monitoring also does not appear to occur as yet. The 2005 audit report recommended that integrated ecosystem monitoring programs including riparian vegetation should be investigated (see DEC 2005 Recommendation 3). This recommendation is reiterated in the current audit (see Section 6.5).

4.4 Native vegetation

Background Native vegetation is important for maintaining the health of individual species of flora and fauna, ecosystem processes and genetic diversity within the Catchment. The degradation or clearing of native vegetation can impact on critical ecosystem services such as the improvement of water quality, nutrient cycling and the provision of resources such as food, shelter and fibre. A reduction in native vegetation cover can also induce soil salinity and acidity, soil erosion, loss of nutrients and changes to flow regimes. The presence of exotic weed species can affect the condition of native vegetation and the extent to which it can

62 2010 Audit of the Sydney Drinking Water Catchment provide habitat. The rate of biodiversity loss accelerates dramatically when a vegetation community declines below approximately 30 per cent of its original area (DECC 2007a). Weeds of national significance that are widespread throughout the Catchment include blackberry, gorse, lantana and serrated tussock. The current audit assessed the extent and condition of native vegetation in the catchment, including the area of native vegetation protected in national parks and reserves, the area of weeds removed, the area of land revegetated, and the area of native vegetation cleared. A number of native vegetation GIS layers have been developed that cover various parts of the Catchment. Approximately 95% of the Catchment area is covered by the South Coast– Illawarra Vegetation Integration Project (SCIVI) mapping (Tozer et al. 2010). This dataset integrates many previous vegetation classification and mapping works, including P5MA (Tindall et al. 2004) to produce a single regional classification and map for the majority of the catchment at a 1:100,000 interpretation scale. The SCIVI dataset was derived from a numerical analysis of 10,832 field sample quadrats, including 9588 compiled from 63 previous vegetation surveys, and additional field sampling and aerial photograph interpretation carried out to fill gaps, enhance spatial resolution and update recent changes in land cover. The native vegetation of the NSW south coast, escarpment and southeast tablelands was classified into 191 floristic assemblages at a level of detail appropriate for the discrimination of threatened ecological communities and other vegetation units referred to in government legislation (Tozer et al. 2010). There are, however, a number of gaps in the SCIVI coverage of the Catchment (see Figure 4.4.1). Fortunately, the vegetation communities of the Upper Coxs River and parts of the Kowmung River sub-catchment are represented by the vegetation of the western Blue Mountains dataset (DEC 2006). There is, however, still a need for vegetation mapping to be undertaken in those parts of the Catchment where existing mapping is incomplete and where limited ground field survey data exist to provide mapping at a scale consistent with the SCIVI dataset (Figure 4.4.1). These regions include parts of the Upper Coxs River, Mid Coxs River, Kowmung River, Upper Wollondilly and Jerrabattgulla Creek sub-catchments. The SCA has developed a technique to map and monitor the condition of native vegetation in the Catchment area using remotely sensed satellite data. Vegetation Condition Index (VCI) layers have been produced annually during the current audit period (no satellite coverage was available for summer 2008) using normalised difference vegetation index (NDVI) (SCA Submission 2010). Corrected normalised vegetation difference index (NDVIc) measures photosynthetic activity in the red and near-infra-red areas of the electromagnetic spectrum and then incorporates a correction factor ‘c’ using shortwave infrared data. Annual VCI maps were produced by the SCA by comparing the NDVIc from the latest image with the mean index value of NDVIc derived from a multi-temporal data set.

Chapter 4 – Biodiversity and Habitats 63

Figure 4.4.1: Location and spatial extent of existing vegetation mapping data for the Catchment The current audit used: • the SCIVI mapping (Tozer et al. 2010) to assess the area and type of native vegetation in the Catchment • the SCA’s VCI to assess the condition of native vegetation in the Catchment.

Findings

Vegetation extent The pattern of vegetation communities across the Catchment is spatially complex (Tozer et al. 2010) (see Figure 4.4.2). No new vegetation mapping or collection of additional vegetation plot data has been undertaken by DECCW in the catchment since 2007. The area of state- wide native vegetation formations (Keith 2004) and cleared land within each of the sub- catchments of the Catchment are summarised in Figure 4.4.3. Of the state-wide native vegetation formations described by Keith (2004), Dry Sclerophyll Forest occupies the largest spatial extent in the Catchment and is most widespread in the Upper Nepean and Wollondilly River sub-catchments. The Mid Coxs River, Kowmung River and Kangaroo River sub- catchments have the largest extent of Wet Sclerophyll Forest. Rainforest occupies the largest area in the Kangaroo Valley and Kowmung River sub-catchments. The Mulwaree River and Braidwood Creek sub-catchments have the largest spatial extent of grasslands. Heathland is most common in the Endrick River sub-catchment, where it occupies over 20% of the sub-catchment area. On a sub-catchment basis, the Little River sub-catchment has the largest percentage cover of native vegetation. The Kowmung River, Lower Coxs River , Lake Burragorang, Nattai River, Woronora River, Upper Nepean River and Upper Shoalhaven River sub-catchments also have a large percentage of native vegetation cover (>80 per cent; Figures 4.4.2 and 4.4.3). The sub-catchments with the lowest percentage cover of native vegetation are the Upper Wollondilly River (<20% cover) and Mulwaree River (<40% cover) (Figures 4.4.2 and 4.4.3).

64 2010 Audit of the Sydney Drinking Water Catchment

Figure 4.4.2: Native vegetation formations of the Catchment

Source: DECCW SCIVI; Statewide vegetation formations are described by Keith (2004). 100%

80% Dry Sclerophyll Forest (grassy subformation) Dry Sclerophyll Forest (shrubby subformation) Forested Wetlands

60% Freshwater Wetlands Grasslands Grassy Woodlands

Area(%) Heathlands 40% Rainforest Wet Sclerophyll Forests (grassy subformation) Wet Sclerophyll Forests (shrubby subformation) Cleared 20%

0% Little River Little Boro Creek NattaiRiver Reedy Creek EndrickRiver MidCoxs River MulwareeRiver KangarooRiver Woronora River KowmungRiver Bungonia CreekBungonia Wollondilly RiverWollondilly WerriberriCreek Braidwood Creek Upper Wollondilly LakeBurragorang LowerCoxs River MongarloweRiver Nerrimunga Creek Jerrabattgula Creek UpperNepean River Wingecarribee River MidShoalhaven River GroseRiver -Blue Mtns Upper ShoalhavenRiver Back Ck &Round Mountain Ck Sub-catchment

Figure 4.4.3: NSW state-wide vegetation formations for the sub-catchments. Source: DECCW SCIVI; Keith 2004 Note: Percentages shown are of mapped sub-catchment areas. Upper Coxs River sub-catchment is not shown as this sub-catchment is not covered by the SCIVI dataset.

Chapter 4 – Biodiversity and Habitats 65 Vegetation condition Changes in native vegetation condition using the SCA’s VCI during the current audit period are shown in Figure 4.4.4. The VCI can be used to identify areas of change in native vegetation caused by both natural and human induced pressures. During the current audit period a series of bushfires altered the condition of native vegetation in some areas of the Catchment. In 2009, the Gulp Road bushfire disturbed the condition of 1133 hectares of vegetation in the western portion of the Kangaroo River sub-catchment. In 2010, 133 hectares were burnt in the Green Wattle Fire within the Lake Burragorang sub-catchment. The VCI was able to identify these fire-related disturbances to the vegetation (See Section 4.5 and Figure 4.5.4). This is discussed further in Section 4.5 (Fire).

Figure 4.4.4: Change in VCI during the current audit period (2007–2010) Source: Data from SCA 2010 Note: No satellite coverage was available for summer 2008.

The proportion of vegetation in each VCI class for each of the sub-catchments in January 2009 is shown in figure 4.4.5. Overall, the area of native vegetation with an average to above average VCI has increased since 2007.

66 2010 Audit of the Sydney Drinking Water Catchment

Figure 4.4.5: VCI in the sub-catchments, January 2009 Source: Data from SCA 2009

A variety of weed control and community education programs have also been undertaken during the current audit period to help improve vegetation condition: • The SRCMA completed a three-year project in 2009 to manage riparian vegetation infestation of Scotch Broom and Blackberry, including fencing and revegetation works and the trial of the Broom Gall Mite as a new bio-control agent to improve the condition of native vegetation in the Braidwood region • The HNCMA conserved 3914 hectares of native vegetation and established 173,197 native plants during the 2010 audit period • The SCA has completed a four-year weed control program in 2009 to contain severe infestations of Wild Pussy Willow and Blackberry in Wingecarribee Swamp. • Implementation of the Sustainable Grazing Program by the SCA to reduce weed infestation of native vegetation and to improve the uptake of grazing management practices that reduce water quality risks from pathogens, nutrients, sediment and pesticides.

Chapter 4 – Biodiversity and Habitats 67 • Survey and treatment by the SCA of Blackberry (1088 ha), Willow (1662 ha) and Serrated Tussock (526 ha) in SCA Special Areas during 2008–2009. Treatment of > 7000 hectares of Serrated Tussock in the Braidwood region in the 2010 audit period. • Implementation of the PROGRAZE and LANDSCAN by the SCA to graziers through on-farm training during the course of the audit period will foster sustainable management practices to reduce the adverse water quality impacts of trampling and grazing of native vegetation cover by livestock in the Catchment.

Implications Many areas within the Catchment still have very good native vegetation cover. This is especially true for lands protected in national parks and nature reserves. Very good native vegetation cover also exists in the SCA Special Areas. During the current audit period an additional 2314 hectares of land in the Catchment was added to the National Park Reserve system. This included land in the Mid Coxs River (Kanangra- Boyd National Park), Upper Nepean (Illawarra Escarpment State Conservation Area, and Dharawal State Conservation Area) and Wollondilly River sub catchments (Blue Mountains National Park and Queens Gap Nature Reserve). The sub-catchments with the lowest percentage of native vegetation cover during the audit period were the Upper Wollondilly River, Mulwaree River and Braidwood Creek sub-catchments. The low percentage cover of native vegetation in these sub- catchments continues to represent a risk to water quality and ecosystem health. While SCIVI provides approximately 95% coverage of the Catchment area, there is a need for vegetation mapping to be undertaken in parts of the Catchment where existing mapping and limited ground field survey data exist. A uniform, integrated vegetation dataset for the entire Catchment still needs to be developed. According to the SCA’s VCI, the condition of native vegetation in the Catchment has improved during the current audit period. There has been a positive move away from a below average and average VCI state in several sub-catchments, which may indicate new vegetation growth as a result of the easing of extended drought conditions in some areas.

Recommendation 7: DECCW, in collaboration with SCA, develop a consistent, uniform and integrated vegetation dataset that covers the entire Catchment.

4.5 Fire

Background Fire is a new indicator that has been recommended for use in the current and future Catchment audits. Bushfires can have many impacts on the quality of water generated in drinking water catchments. Bushfires can indirectly increase the rate of erosion in a catchment by reducing the resistance to surface soil movement and by increasing the velocity of the water runoff (Brown 1972; Leitch et al. 1983; Diaz- Fierros et al. 1987; Scott and Van Wyk 1990; Rustomji and Hairsine 2006). Increases in runoff are attributed to changes in soil hydrophobicity, reduced vegetative cover and the low cohesion of ash and desiccated soil (Leitch et al. 1983; Prosser and Williams 1998; Shakesby et al. 2000; 2003; 2006). The magnitude of the effects depends on the extent of the fire, its intensity, the rate of vegetation regeneration, soil

68 2010 Audit of the Sydney Drinking Water Catchment properties, topography, geology, and rainfall patterns after the fire (Krogh et al. 2008). If the vegetation in the catchment is extensively removed by a fire and heavy rain occurs soon afterwards, there can be serious degradation of water quality. Increased water runoff after a fire will include suspended soil and ash particles and can cause increased sediment and turbidity in streams, wetlands and dams (Krogh et al. 2008). In addition, forest fires can change the pattern of water use by the forest leading to changes in streamflow, with streamflow increasing in the period immediately after the fire and decreasing streamflow in the period of rapid vegetation regrowth (8 to 50 years after the fires) (Krogh et al. 2008). In native forests these effects vary in magnitude according to rainfall and the severity of fires (Rustomji and Hairsine 2006). Fires can remove the buffering capacity of vegetated riparian zones and they can have complex impacts on species composition and biodiversity in post-fire habitats, including the potential for localised species extinctions (Krogh et al. 2008). Fires can also produce conditions that favour the establishment of noxious weeds which can compete with and threaten important native species. During December 2001 to January 2002 (Summer), a number of large fires burnt simultaneously across a large proportion of land in Sydney’s drinking water supply catchments. The variety of research undertaken by the SCA and a range of collaborators since 2002 in relation to bushfire, catchment management and water quality is relatively well documented (e.g. Chafer 2007). A series of collaborative studies between the SCA and CSIRO were initiated in response to the 2001–2002 bushfires which has lead to an improved understanding of the impacts of fire on water quality, erosion, vegetation management and catchment health. Extensive redistribution of surface soil and nutrients on burnt hill slopes in the Nattai River sub- catchment and increased sediment delivery rates to river networks were identified following the fires (Wilkinson et al. 2007). Fire can also change the structure and composition of vegetation communities in the catchment. Fire regimes in the Catchment that are characterised by very short or invariable intervals or peat fires pose a significant threat to the upland swamps in the Catchment which play an important hydrological function to regulate water quality (Keith et al. 2006). A clear understanding of the spatial extent of land burnt by fire is therefore important in identifying the potential impacts of bushfires on flora and fauna, catchment health, erosion and water quality. The current audit focused on the area and extent of land burnt by bushfire and hazard reduction burns. The current audit also provided information on management activities that have been undertaken to minimise the impacts of fire on water quality and catchment health in the Catchment.

Findings

Bushfires During the current audit period approximately 2276 hectares of the Catchment were burnt by bushfires (SCA 2010a and SCA 2010b). The majority of bushfires which occurred in the Catchment were less than 250 hectares in size. The area of land burnt by bushfires on a sub-catchment basis is summarised in Table 4.5.1. The largest spatial extent of bushfires occurred in the Kangaroo River sub-catchment (1151 ha), followed by the Back & Round Mountain Creek (290 ha) sub-catchment. During the 2010 audit period the greatest number of bushfires occurred in the Lake Burragorang sub-catchment (Figure 4.5.1). Sub-catchments shown are only those for which bushfire data were available.

Chapter 4 – Biodiversity and Habitats 69 The cause of the bushfires which occurred in the Catchment during the current audit period is summarised in Figure 4.5.2. The largest proportion of bushfires which occurred in the Catchment during the 2010 audit period was caused by naturally occurring lightning strikes (> 40%). The cause could not be determined for 24% of the bushfires which occurred in the Catchment during the 2010 audit period (Figure 4.5.2).

Table 4.5.1: Area burnt by bushfires across the Catchment during the 2010 audit period

Bushfires (ha)

Sub-catchment 2007–08 2008–09 2009–10 Back Creek & Round 74.40 215.90 Mountain Creek Boro Creek 174.23 49.65 Bungonia Creek 14.28 7.28 Jerrabattgulla Creek 11.92 Kangaroo River 11.61 1131.24 8.46 Lake Burragorang 21.90 137.07 Little River 8.65 Lower Coxs River 23.95 Mid Coxs River 21.14 Mongarlowe River 31.50 4.71 Nattai River 1.34 Nerrimunga River 110.98 Reedy Creek 4.52 Upper Nepean River 66.41 22.64 Wingecarribee River 3.07 Wollondilly River 11.00

Source: Data from SCA 2010

70 2010 Audit of the Sydney Drinking Water Catchment 8

7

6

5

2009-10 4 2008-09 2007-08 3 Numberbushfires of

2

1

0 LittleRiver BoroCreek NattaiRiver ReedyCreek MidCoxsRiver KangarooRiver BungoniaCreek WollondillyRiver LowerCoxsRiver MongarloweRiver LakeBurragorang MountainCreek NerrimungaCreek WingecarribeeRiver JerrabattgullaCreek UpperNepean River BackCreek Round & Sub-catchment

Figure 4.5.1: Number of bushfires by sub-catchments during the 2010 audit period Source: Data from SCA 2010 Note: No bushfires were recorded for the other sub-catchments.

Unknown Accidental Arson Campfire Debris Burning Equipment Use Incendiary Lightning Miscellaneous/Other Undetermined

Figure 4.5.2: The cause of bushfires occurring in the Catchment during the 2010 audit period Source: NSW Rural Fire Service. Operational GIS Database 2010

Chapter 4 – Biodiversity and Habitats 71 Fire management activities across the Catchment There were a number of fire management activities undertaken during the current audit period. Fire management activities are undertaken by the SCA in the Special Areas in order to maximise the protection of water quality and integrity (SASPoM; SCA 2007a).The SCA in partnership with DECCW maintained fire roads and implemented a program of fire break slashing and hazard reduction burns. The implementation of fire management activities can often be strongly influenced by weather conditions. The Auditor notes the following actions: • In 2007–08 the SCA planned, prepared and implemented 11 hazard reduction burns, covering an area of 2531 hectares. • As part of this program the SCA and DECCW also cleared and slashed 215 kilometres of trail to ensure strategic access for fire operations staff (SCA 2008d). • During 2008–09 the SCA and DECCW completed 11 hazard reduction burns covering an area of over 6765 hectares. • Wet vegetation and unsuitable weather conditions hampered SCA attempts to undertake an additional eight hazard reduction burns during this period. • In order to provide strategic access for fire operations staff to Special Areas the SCA slashed 971 hectares of fire-breaks during 2008–2009 (SCA 2009a). • The NSW Rural Fire Service conducted 15 prescribed burns covering a total of 2085 hectares within the Catchment area during the 2010 audit period (NSW Rural Fire Service: Bushfire Risk Information Management System 2010). The location and extent of prescribed burns occurring within the last 3 years in the Catchment are provided in Figure 4.5.3. Prescribed burns affected approximately 16,430 hectares of the catchment during the current audit period. The greatest extent of prescribed burns occurred in the northern portion of the Catchment in the land areas surrounding Lake Burragorang (i.e. the Lake Burragorang, Mid Coxs River, Kowmung River, Wollondilly River and Nattai River sub-catchments).

Fire and vegetation condition During the current audit period the SCA has been developing a VCI to monitor native vegetation health across the Catchment. The VCI uses satellite imagery to calculate the relative health of vegetation, taking into account changes over time, to determine an average that can be mapped. The VCI can also be used to identify areas of fire and other disturbances to vegetation in the Catchment. A fuel load index has also been developed by the SCA to measure the available vegetation that could be consumed by fire to inform emergency response and planning teams. The impact of some bushfires on native vegetation in the Lake Burragorang and Kangaroo River sub-catchments during the 2010 audit period is illustrated in Figure 4.5.4.

72 2010 Audit of the Sydney Drinking Water Catchment 3000

2500

2000

2007- 08 1500 2008 - 09

Area (ha) Area 2009 - 10

1000

500

0 Little River Little Nattai River Nattai Reedy Creek Mid CoxsMid River Kangaroo River Kangaroo Kowmung River Kowmung Wollondilly River Wollondilly Werriberri Creek Werriberri Creek Woodford Braidwood Creek Braidwood Lake BurragorangLake LowerCoxs River Wingecarribee River Wingecarribee Sub-catchment

Figure 4.5.3: Location and extent of prescribed burns occurring within the 2010 audit period in the Catchment Source: DECCW (PWG) 2010

Figure 4.5.4: Impact of bushfires on native vegetation in the Lake Burragorang and Kangaroo River sub-catchments during the 2010 audit period Source: Data from SCA 2010

Chapter 4 – Biodiversity and Habitats 73 Future directions DECCW and the SCA will continue to address the actions and targets set out in the Special Areas Strategic Plan of Management (SASPoM) (SCA 2007a) to protect the drinking water supply catchments and maintain the ecological integrity of the Catchment to provide a reliable supply of safe, clean, bulk raw water. The impact that erosion of sediment after bushfires has on the quality of drinking water in reservoirs is of concern to the Auditor. In the future, the use of fire intensity data and analysis of rainfall data coincident with fire events would help quantify the impacts of fire-induced erosion on water quality in the Catchment. The SCA should continue to assess the effects of high intensity fire on soil erosion and water quality in cooperation with DECCW. Programs that are already in place for fire management in the Catchment: • DECCW and the SCA will continue to implement current reserve and Special Area fire management plans and strategies, pending finalisation of the joint fire management policy and the Special Areas Fire Management Operations Plan. • The SCA and DECCW will develop a joint fire management policy in line with legislative requirements. • DECCW and the SCA will review the Fire Operations Plan for Warragamba, with reference to the proposed Joint Fire Management Policy and other studies, and expand the plan to incorporate all Special Areas. • When updating existing Fire Management Plans within Special Areas, the SCA and DECCW will review these plans to incorporate the Fire Management Policy (above) and results of post fire monitoring and research including that of Keith et al. (2006). • DECCW and the SCA will continue to support and/or attend bushfire management committees. • The SCA and DECCW will continue to monitor impacts of fire on water quality and ecological integrity. • Standardise reporting and mapping of spatial distribution and extent of bushfires. The SCA, Rural Fire Service and DECCW should continue to work to collate spatial information to track and record information on the extent of bushfires and hazard reduction/prescribed burns occurring in the Catchment, so that a single accurate estimate can be reported in future audits. The Auditor supports the wide variety of fire-related programs that are currently being undertaken in the Catchment. However, during the assessment the Auditor noted a number of discrepancies between the areas and locations of bushfires reported by the SCA, Rural Fire Service and DECCW in some sub-catchments. It is therefore recommended that, in the future, the Rural Fire Service, SCA and DECCW integrate their spatial datasets across all sub-catchments so that a single estimate for the area burnt by hazard reduction burns and bushfires can be reported in future catchment audits.

Recommendation 8: The Rural Fire Service, in cooperation with SCA and DECCW, integrate their spatial datasets across all sub-catchments so that a single, consistent estimate for the area burnt by hazard reduction burns and bushfires can be reported.

74 2010 Audit of the Sydney Drinking Water Catchment 4.6 Wetlands Wetlands are important and restricted habitats for dependent biota and play vital roles in landscape function, hydrology and carbon sequestration. They are also likely to be one of the most sensitive components of the terrestrial biosphere to global climate change (Keith et al. 2010). Upland swamps and wetlands in the catchment facilitate the flow of high quality water through catchments and can provide habitats and food for a variety of fauna and flora (Keith et al. 2006). Water resource development and urbanisation are implicated as major factors influencing the distribution and condition of wetlands in Australia (Kingsford 2000). Wetlands in the Catchment are particularly vulnerable to changes to surface and sub- surface drainage from localised disturbances including invasion of exotic species, road and drain construction and underground mining. Since many wetlands in NSW are under increasing pressure from human activity and climatic changes, it is increasingly important to protect those that remain (DECCW 2010c). The NSW State Plan includes a target for improving the condition of important wetlands: That by 2015, there is an improvement in the condition of important wetlands, and the extent of those wetlands is maintained. The Natural Resources Commission of NSW has defined ‘important wetlands’ as being those listed under the Ramsar Convention or in the Directory of Important Wetlands in Australia. The Catchment includes several nationally significant wetlands, which are listed in the Directory of Important Wetlands in Australia (Table 4.6.1) (Environment Australia 2001) and wetlands that are listed under the Environment Protection and Biodiversity Conservation Act 1999. Although there are no wetlands classified as Ramsar sites of international significance within the Catchment, there are other wetlands which may be nationally and/or state significant depending on more locally specific criteria. For example, many of the swamps in the Upper Coxs, Upper Nepean and Paddys River areas are listed as endangered ecological communities under both state and federal legislation. The Federal Temperate Highland Peat Swamps on Sandstone listing (DEH 2005, DSEWPaC 2010) specifically includes: • Swamps on the Newnes Plateau (some of which occur in the headwater tributaries of the Coxs River). • Butlers Swamp (in the upper reaches of the Nepean River sub-catchment). • Gallahers Swamp (in the upper reaches of Avon River), Upper Nepean sub- catchment. • Jumping Rock Swamp (in the Paddys River catchment, Wollondilly River sub- catchment). • North Pole Swamp (upper reaches of Dudewaugh Creek, Upper Nepean sub- catchment). • Paddys River Swamps, including Hanging Rock Swamp, Mundego Swamp, Long Swamp and Stingray Swamp (upper reaches of Paddys River catchment). • Rock Arch Swamp (upper reaches of Avon River). • Stockyard Swamp (upper reaches of Dudewaugh Creek, Upper Nepean sub- catchment). • Wildes Meadow Swamp (upper reaches of Wildes Meadow Creek, Kangaroo River sub-catchment). • Wingecarribee Swamp (upper reaches of Wingecarribee River).

Chapter 4 – Biodiversity and Habitats 75 Table 4.6.1: Wetlands of the Catchment listed in the Directory of Important Wetlands in Australia (Environment Australia, 2001)

Site Wetland Area Elevation code Name of wetlands Sub-catchment type (ha) (m) Wingecarribee NSW093 Swamp Wingecarribee River B15 320 680 m ASL Lake Bathurst/The NSW066 Morass Mulwaree River B6 1350 675 m ASL NSW091 Thirlmere Lakes Little River B5, B15 50 300m ASL NSW082 Long Swamp Wollondilly River B15 88 610m ASL NSW074 Boyd Plateau Bogs Kowmung River B15 Variable 1100m ASL Budderoo National 560 – 580 m NSW075 Park Heath Swamps Kangaroo River B15, B13 1150 ASL

Many of the upland swamps on the Woronora Plateau are also consistent with the definition of Temperate Highland Peat Swamps on Sandstone community (albeit at slightly lower elevations). The Department of Environment Water Heritage and Arts (DEWHA) is currently in the process of reviewing this listing which will further clarify the status of these swamps. Reporting for the current audit focused on the size, type, location and condition of wetlands in the Catchment. The audit also provides information on the management activities that have been undertaken to improve wetland condition in the Catchment during the current audit period.

Findings

Size, type and location of wetlands There are several existing datasets which describe the size, type and location of wetlands within the Catchment, however they have a wide range of spatial resolutions and have been constructed using a variety of different classification techniques. Several datasets describe the wetland vegetation communities of different parts of the Catchment. Unfortunately these datasets are often at different scales and different levels of vegetation-type resolution. This includes SCIVI (Tozer et al. 2010), which covers the largest area of the Catchment; the native vegetation layer of the Woronora, O’Hares and Metropolitan Catchments (NPWS 2003); the native vegetation of the Sydney Metropolitan Catchment Management Authority Area (DECCW 2009b); and the Vegetation of the Western Blue Mountains (DEC 2006). The wetlands of NSW layer of Kingsford et al. (2004), derived from Landsat Thematic Mapper (TM) data from the mid 1990s, covers the entire catchment area, however this is at a relatively broad scale (1:250,000). During the 2010 audit period the SCA updated their wetlands spatial data layer using a combination of 2001 and recent 2008 digital aerial photography. Wetlands were classified by the SCA to the Australian and New Zealand Environment and Conservation Council (ANZECC) standard (Table 4.6.2) (see Environment Australia 2001). The current SCA classification recognised nine different kinds of inland wetlands in the Catchment based on their geophysical, hydrological and ecological characteristics (Table 4.6.2). Permanent rivers and streams; including waterfalls covered the largest spatial extent in the Catchment (2191 ha) followed by the seasonal/intermittent freshwater lakes (> 8 ha) and floodplain lakes category (1920 ha).

76 2010 Audit of the Sydney Drinking Water Catchment Table 4.6.2: Wetland groups classified by the SCA using the ANZECC standard as described in Chapter 2 of The Directory of Important Wetlands (Environment Australia 2001) Wetland category Code Description B1 Permanent rivers and streams; includes waterfalls B2 Seasonal and irregular rivers and streams B4 Riverine floodplains; includes river flats, flooded river basins, seasonally flooded grassland, savannah and palm savannah Seasonal/intermittent freshwater lakes (> 8 ha), floodplain B6 lakes B9 Permanent freshwater ponds (< 8 ha), marshes and Inland wetlands swamps on inorganic soils; with emergent vegetation waterlogged for at least most of the growing season B10 Seasonal/intermittent freshwater ponds and marshes on inorganic soils; includes sloughs, potholes; seasonally flooded meadows, sedge marshes B13 Shrub swamps; shrub-dominated freshwater marsh, shrub carr, alder thicket on inorganic soils B15 Peat lands; forest, shrub or open bogs B17 Freshwater springs, oases and rock pools Human-made C2 Ponds, including farm ponds, stock ponds, small tanks wetlands (generally < 8 ha)

At the sub-catchment level, the Mulwaree River sub-catchment contains the largest area of permanent rivers and streams; including waterfalls (575 ha) followed by the Endrick River, Kangaroo Valley and Mid Coxs River sub-catchments (Figure 4.6.1.) The Wollondilly River and Upper Nepean River sub-catchments contain the largest areas of peatlands; forest, shrub or open bogs. The Kangaroo Valley sub-catchment contains the largest area of freshwater springs, oases and rock pools (396 ha). Wetland condition attributes, however, are not represented in the SCA wetlands spatial data layer.

Chapter 4 – Biodiversity and Habitats 77 Permanent rivers and streams; includes waterfalls (ha)

600

500

400

300 Area (ha) Area 200

100

0 Nattai Nattai River Grose RiverGrose Endrick River Kangaroo River Kangaroo Mid Coxs River River Mulwaree Woronora River Woronora Bungonia Creek Bungonia Werriberri Creek Werriberri Wollondilly Wollondilly River Lower Coxs River Lower Coxs River Upper Upper Wollondilly Upper Nerrimunga Creek Nerrimunga Upper Nepean River Nepean Upper Wingecarribee River Wingecarribee Mid Shoalhaven Mid River Shoalhaven Sub-catchment

Figure 4.6.1: Area of permanent rivers and streams; including waterfalls in the sub- catchments Source: Data from SCA 2010 Note: Sub-catchments shown are those currently classified to the ANZECC standard as described in Chapter 2 of The Directory of Important Wetlands (Environment Australia 2001).

SCIVI classification Wetland vegetation communities for 95% of the Catchment are represented by the SCIVI vegetation map (Tozer et al. 2010). The SCIVI dataset provides a more detailed vegetation categorisation than the SCA dataset. Vegetation assemblages, including wetlands, in SCIVI were derived by a numerical analysis of over ten thousand field sample quadrats, incorporating data from over sixty previous vegetation surveys, including the P5MA vegetation mapping coverage (Tozer et al. 2010). A summary of the area of forested and freshwater wetland vegetation formations mapped by DECCW (Tozer et al. 2010) and DEC (2006) in the sub-catchments is included in Figure 4.6.2. Forested wetlands are restricted to the riverine corridors and to floodplains which are subject to periodic inundation within the Catchment. Hydrophytes in the understorey differentiate forested wetlands as a separate vegetation formation (Keith 2004). The Wollondilly River sub-catchment has the largest area of forested wetlands formation, followed by the Mid Coxs River sub- catchment. The Upper Nepean River sub-catchment has the largest area of freshwater wetlands, followed by the Mulwaree River and Kangaroo River subcatchments (Figure 4.6.2). A composite wetland vegetation map based on data derived from Tozer et al. (2010) and DEC (2006) is included in Figure 4.6.3. More detailed sub-catchment maps are provided in the sub-catchment summary section (Appendix C).

78 2010 Audit of the Sydney Drinking Water Catchment

Figure 4.6.3: Location of wetlands* and the spatial distribution of wetland vegetation communities in the Catchment

Source: DECCW (2010) SCIVI and DEC 2006 (Upper Coxs River sub-catchment)

*As listed in the Directory of Important Wetlands in Australia (Environment Australia 2001)

Figure 4.6.2: Area of state-wide wetland vegetation formations (Keith 2004) in the Catchment Source: Sub-catchment data from SCIVI (Tozer et al. 2010) and DEC 2006 (Upper Coxs River sub-catchment)

According to the SCIVI vegetation classification, the Mulwaree River sub-catchment has the largest area of Tableland Lacustrine Herbfield (2100 ha). The Upper Nepean sub-catchment has the largest area of Coastal Upland Swamp (2549 ha) followed by the Woronora River sub-catchment (234 ha) The Wollondilly River sub-catchment contains the largest areas of Tableland bog (504 ha), Tableland Swamp Flats Forest (909 ha) and Tableland Swamp Forest (1289 ha). The largest areas of Blue Mountains Shoalhaven Hanging Swamps occur in the Kangaroo River sub- catchment (1358 ha) followed by the Lower Coxs River sub-catchment (207 ha). The Wingecarribee River sub-catchment contains the greatest extent of Tableland Swamp Meadow (534 ha).

Wetland condition There are a variety of pressures or disturbances throughout the Catchment that may adversely affect wetland condition. Long-term data on the condition of wetland types which occur across the Catchment area are rare and often restricted to individual swamps (e.g. Wingecarribee Swamp (NPWS, DEC and SCA 2007). Wetland mapping in the Catchment has also not been undertaken at a frequency which adequately enables an assessment of change in wetland extent or condition over the current audit period. In addition, no standardised procedure is currently available for documenting wetland condition in the Catchment. DEC (2006) mapped the freshwater wetland vegetation communities of the Upper Coxs River sub-catchment (which occur outside the SCIVI coverage). This study produced a detailed 1:25,000 scale map using detailed API and a variety of disturbance types, which impact freshwater wetlands within the Upper Coxs River sub-catchment, were identified and mapped. This included degradation associated

Chapter 4 – Biodiversity and Habitats 79 with: adjacent roads and trails; plantations and woodlots; fire; and vegetation clearing. The intensity of disturbance impacting the freshwater wetlands of the sub- catchment mapped by DEC (2006) are summarised in Figure 4.6.4. This analysis identified that Mountain Hollow Grassy Fen had the highest level of disturbance, with very few areas having experienced a low level of disturbance. The Newnes Plateau Shrub Swamps and Hanging Swamps had most of their area categorised in the low disturbance level.

120

100

80

Low 60 Moderate

Area(ha) High

40

20

0 Newnes Plateau Shrub Newnes Plateau Hanging Mountain Hollow Grassy Fen Swamp Swamp Vegetation Community

Figure 4.6.4: The area of freshwater wetlands mapped, and the proportion of three disturbance intensity classes identified, within the Upper Coxs River sub-catchment Source: DEC (2006)

Farmers Creek Swamp Farmers Creek Swamp is located at the top of Farmers Creek catchment. The Clarence Water Transfer Scheme transfers water from the Clarence Colliery Dam to settling ponds above Farmers Creek Swamp where the water then flows by gravity through an outlet pipe located at the top of Farmers Creek Swamp. It appears likely that channelling and erosion in Farmers Creek Swamp downstream of the outlet pipe is related to relatively recent and above average historical flows into the swamp and the flows from the Clarence transfer scheme are likely to have been a major contributor to the gullying in the upper part of the swamp (DECCW 2010d). Proposals to address erosion issues in the transfer of water through the swamp are currently underway. This swamp is likely to be able to regenerate naturally if water transfers are piped around the swamp (DECCW 2010d).

Recommendation 9: Lithgow City Council and Centennial Coal should ensure that water transfers from the Clarence Water Transfer Scheme are piped around, rather than flow through, Farmers Creek Swamp.

80 2010 Audit of the Sydney Drinking Water Catchment Longwall mining impacts on swamps A number of recent reports and reviews have identified impacts to swamps as a result of longwall mining in and adjacent to the Catchment (e.g. Gibbins 2003, Krogh 2007, DECC 2007b, Aurecon 2009a, Centennial Coal 2009, NSW Planning Assessment Commission 2009, DECCW 2009a). The Scientific Committee, established by the Threatened Species Conservation Act 1995, made a determination in 2005 to list ‘Alteration of habitat following subsidence due to longwall mining as a key threatening process’, noting that subsidence associated with longwall mining has contributed to adverse effects on upland swamps. In the current audit, six submissions were received relating to concerns about longwall mining impacting swamps. The primary cause of mining-related impacts to swamps is subsidence (including valley closure and upsidence) fracturing the relatively impervious base of the swamp leading to the loss of perched aquifers and, as a result, causing increased desiccation. The effect of mining-induced surface cracking on upland swamps can be severe, where these bodies are in effect perched water tables dependent on ponded rainfall on top of thin clay, shale or sandstone floors. Rupturing of these seals is quite likely, especially where they rest on bare rock rather than deep soil, or where they occur close to cliffs (SKM 2007). These perched water tables are easily fractured and drained by the tensile strains above an advancing subsidence wave, putting at risk upland swamps and other groundwater-dependent ecosystems in its path (SKM 2007). Once a swamp loses its moisture it becomes more prone to fire and erosion (Krogh 2007, Tomkins and Humphreys 2006). The Southern Coalfield Inquiry identified a significant possibility that undermining of valley infill swamps could cause drainage, water table drop and consequent degradation to swamp water quality and associated vegetation (DoP 2008b). More recent data have identified further impacts to a range of other upland swamp types, including the ‘headwater’ swamp type discussed by the Southern Coalfield Inquiry (BHPBIC 2009, NSW Planning Assessment Commission 2009; Aurecon 2009a; DECCW 2009a). Piezometer monitoring in the Upper Kangaroo Creek Swamp (Upper Coxs River sub-catchment) provides a clear example of mining impacts on perched aquifer levels (DECCW 2010e). Where swamps are desiccated through the cracking of swamp beds and draining of perched aquifers, those species specifically adapted to swamp environments and high soil moisture content are likely to be lost (DECC 2007b). Whether these species can return or not will depend on the longevity of impacts and the ability of species to recolonise the area (DECC 2007b). Impacts to Drillhole Swamp in the Avon River catchment (Young 1982) clearly illustrates that these impacts can last for considerable (decadal) periods of time. There are currently no proven remediation techniques that are capable of rehabilitating swamps once impacted by mining subsidence. In some areas of the Catchment (e.g. Lizard Creek catchment and the Upper Coxs River sub-catchment), swamp species are also potentially at risk from alkaline or acid minewater discharge (DECC 2007b). Following the Planning Assessment Commission’s review of the Metropolitan Coal Project (NSW Planning Assessment Commission 2009), the Commission noted that the collection of further data was necessary to resolve significant outstanding questions in relation to the potential impacts of conventional and non-conventional subsidence on swamps.

Chapter 4 – Biodiversity and Habitats 81 Two of the recommendations from the Southern Coalfield Inquiry (DoP 2008b) were that: • the acceptability of impacts under Part 3A of the EP&A Act should be determined within a framework of risk-based decision making • government should provide improved guidance to both the mining industry and the community on the significance of, and value for, natural and other environmental features to inform company risk-management processes, community expectations and government approvals. To assist in addressing these recommendations and statutory provisions, it is understood that the DECCW has developed Draft Upland Swamp Environmental Assessment Guidelines. The aims of the guidelines are to improve environmental assessment and assist both the underground mining industry and the Government to further understand subsidence impacts on upland swamps in the Southern and Western coalfields. This is particularly important given the projected increase in mining assessments under Part 3A and the significant number and areal extent of swamps which overlay areas of current production and exploration title (see Figure 4.6.5). There is a clear need for DECCW to finalise its Upland Swamp Environmental Assessment Guidelines in order to achieve consistency in the application of risk assessment methodology for swamps over areas of longwall mining in the Catchment.

Figure 4.6.5: Wetland vegetation and current mining production title Source: SCIVI DECCW (2009), I&I NSW (2010)

Recommendation 10: DECCW finalise its Draft Upland Swamp Environmental Assessment Guidelines in order to achieve consistency in the application of risk assessment methodology for swamps over areas of longwall mining in the Catchment.

82 2010 Audit of the Sydney Drinking Water Catchment Maintenance and monitoring of wetland condition in the Catchment A variety of wetland management activities have been undertaken during the 2010 audit period to improve wetland condition in the Catchment. Wetlands within the Catchment that are identified in the Directory of Important Wetlands in Australia (Environment Australia 2001) continued to be a priority for the HNCMA during the 2010 audit period. In line with state targets to improve the condition and maintain the extent of important wetlands, the HNCMA restored 69 hectares of priority wetlands. In 2008, consultants were appointed to implement the on-ground actions identified in the Lake Bathurst/The Morass and Paddys River Management Plans. Stingray Swamp at Penrose in the Southern Highlands had a dedicated landcare group established during the current audit period to help in its restoration. This joint HNCMA and Wingecarribee Council project included mapping and removal of weeds (e.g. pine, blackberry, honeysuckle) from around the transitional ecotone. Wingecarribee Shire Council identified 346 wetlands within the Shire boundary and during the current audit period undertook a project under the Wetland Management Strategy, which included a study of the function of 33 indicator wetlands. Results from this study indicated that the highest total value wetlands within the Wingecarribee Shire occur within SCA protected areas. Many of the montane swamps and peat lands have been listed as an endangered ecological community in the Wingecarribee Shire under the Threatened Species Conservation Act 1995. Wingecarribee Swamp continues to be a priority for wetland management activities in the Catchment. The swamp collapsed in 1998 and a large volume of peat was washed into the reservoir. Water drained from the swamp allowing the peat to dry out and leaving the swamp susceptible to infestation by weeds. The management of Wingecarribee Swamp is guided by the Wingecarribee Swamp and Special Area Plan of Management (WSSAPoM) (SCA 2007b). Further details on Wingecarribee Swamp are included in the (Wingecarribee River) sub-catchment summary section (Appendix C). The SRCMA enhanced and rehabilitated 50 hectares of native wetland vegetation and enhanced the connectivity of 51 hectares of wetland vegetation during the current audit period (SRCMA Submission 2010).

Implications A variety of threats to wetland vegetation community extent and condition have been identified (Tozer et al. 2010). An understanding of relationships between wetland persistence and climate is imperative for predicting, mitigating and adapting to the impacts of future climate change on wetland extent and function (Keith et al. 2010). At the time of the current audit the wetland inventory of the SCA was incomplete. Several sub-catchments have wetlands which have been mapped but not classified and attributed according to ANZECC standards (e.g. Boro Creek, Back Creek & Round Mountain Creek, Braidwood Creek, Kowmung River, Jerrabattgulla, Lake Burragorang, Little River, Mongarlowe River, and Upper Shoalhaven River). The Auditor notes a number of discrepancies were identified between the SCA wetland layer and the SCIVI representation (e.g. see Endrick River sub-catchment summary in Appendix C). DECCW and the SCA should finalise their classifications of wetlands to produce a complete and consistent coverage of the Catchment at a level that meets ANZECC standards (see Environment Australia 2001). Additional threats to the extent and condition of upland swamps in the Metropolitan and Woronora Special Areas include impacts associated with longwall mining. The fracturing of the relatively impervious base of the swamp and alterations to drainage patterns associated with underground coal mining can lead to degradation in these swamps (Krogh 2007, NSW Planning Assessment Commission 2009, DECCW 2009a). A number of swamps in the Metropolitan Special Areas have already been impacted and it is possible that further swamps may be impacted by current (or future) mining operations. The Auditor notes that subsidence levels predicted for

Chapter 4 – Biodiversity and Habitats 83 swamps over the approved Dendrobium Area 3 operation and over the proposed Bulli Seam Project have the potential to lead to adverse impacts on swamps (MSEC 2007, BHPBilliton 2009). It is clear that there is currently no standardised methodology to assess the condition of wetlands in the Catchment. Qualitative data on three categories of disturbance were available for swamps in the Coxs River catchment, however, other condition assessments were limited to individual swamps. There is a clear need for a standardised approach to the assessment of wetland condition throughout the Catchment. Targeted remote sensing of wetland vegetation around suspected areas of wetland degradation should also be undertaken to quantify the long-term impact of fragmentation by clearing, road works or longwall mining on the health of upland swamps within the Catchment area. While remote assessment of wetland condition by aerial photography or satellite imagery can potentially provide an indication of where wetland vegetation may be subject to degradation and/or changes in areal extent, more direct measurement of perched water tables and flora and fauna are required to fully assess the ecological consequence of impacts to these wetlands.

Recommendation 11: DECCW and the SCA should finalise their classifications of wetlands to produce a complete and consistent coverage of wetlands in the Catchment.

4.7 Physical form

Background The physical form of rivers in the Catchment area has not been reviewed in previous audits. Physical form describes the geomorphic complexity of a river and may be used as a measure of the recovery potential of degraded rivers (NOW 2009). Generally, highly structured habitats are indicative of near intact or good river health because they contain more native aquatic taxa compared to simple structured habitats. The River StylesTM framework (Brierley and Fryirs 2005) has been established as the method to inform the physical form of rivers in NSW (NOW 2009). The framework provides a capacity to prioritise management strategies for river rehabilitation and conservation. There are 4 stages in implementing the River StylesTM framework: 1. Baseline survey of river character and behaviour 2. Assessment of the geomorphic condition of each reach of each river style in the catchment 3. Prediction(s) of likely future changes in geomorphic condition and geomorphic recovery potential 4. Setting realistic target conditions for river rehabilitation. River character and behaviour determine the river style. These are typically characterised by a distinctive set of attributes (e.g. topography, geology, climate, hydrology, vegetation cover), and analysed in terms of channel geometry, planform and geometric units that make up a river reach such as floodplains, levees, pools and riffles. As indicated above, geomorphic condition is given by geomorphic heterogeneity. Near intact condition is characterised by reaches with numerous geomorphic units

84 2010 Audit of the Sydney Drinking Water Catchment and an extensive riparian corridor, whereas the degraded condition is characterised by reaches that have homogenous sand sheets that infill pools and smother channel beds, and a non-existent riparian corridor. There are typically 4 categories of geomorphic condition: Near Intact, Good, Moderate and Degraded. The geomorphic recovery potential of a reach is dependent on geomorphic condition and by limiting factors and pressures to recovery such as human-induced constraints on water and sediment transfer and vegetation patterns. Hence, reaches with low recovery potential are typically those that are categorised as in the Moderate or Degraded condition, and reaches with very high recovery potential are typically those that are Near Intact or in Good condition. The recovery potential is also used to identify reaches that need to be conserved or those that require strategic management, where management efforts focus on maintaining or improving the high conservation values of reaches or stopping impacts arising from poor upland catchment practices. The methodology for determining river styles in NSW was developed by Brierley and Fryirs (2005) and has been applied to the Hawkesbury–Nepean Catchment Management Authority area (DLWC 2001) and to several coastal catchments, including the Shoalhaven catchment (Brierley et al. 1999).

Findings The River Styles assessments in the HNCMA area and the Shoalhaven catchment are summarised in maps of river styles, geomorphic condition, and recovery potential (Figures 4.7.1, 4.7.2 and 4.7.3). In both assessments, major water storages are identified as a separate River Style (i.e. reservoir). Approximately 50% of the HNCMA area falls within the Catchment area. A total of 10 River Styles are represented in this area, with the greatest numbers of Rivers Styles found in the Upper Coxs (8 river styles), Wingecarribee (6 river styles), Upper Wollondilly (6 river styles), Upper Nepean (6 river styles) and Wollondilly (6 river styles) sub-catchments (Figure 4.7.1). The distribution of River Styles is largely controlled by geological conditions and long-term landform evolutionary processes. Typically, headwater and minor alluvial reaches are found on plateaux, capped predominantly by Triassic Hawkesbury or Narrabeen Group sandstones (DLWC 2001). Below these areas is the escarpment zone which is characterised by waterfalls. Below the escarpment, the River Style may change into Gorge or Confined Group River Styles depending on the rock type. The extent of recovery potential and condition of each sub-catchment is summarised in Tables 4.7.1 and 4.7.2. Of significance are the Mulwaree and Upper Wollondilly River, Werriberri Creek and Upper Coxs River sub-catchments, which are predominantly in Degraded or Moderate condition and hence have low to moderate recovery potential (Figures 4.7.2 and 4.7.3). The sub-catchments that surround Lake Burragorang are predominantly in Near Intact or Good condition. The River Styles assessment in the Shoalhaven catchment identified 10 River Styles. The distribution of River Styles is primarily controlled by the lithology, valley width and topography of the sub-catchment. The greatest numbers of River Styles are found in the Bungonia Creek (8 river styles), Kangaroo River (6 river styles) and Boro Creek (6 river styles) sub-catchments (Figure 4.7.1). The least number of river styles is in the Back Creek/Round Mountain Creek (2 river styles) sub-catchment. Collectively, around 25% of the river reaches in the Shoalhaven catchment have been identified as being predominantly (> 75%) in Moderate or Degraded condition and accordingly have moderate to low recovery potential (Figures 4.7.2 and 4.7.3; Tables 4.7.1 and 4.7.2). These include reaches in the Nerrimunga River, Boro Creek, and Back Creek/Round Mountain Creek sub-catchments (Tables 4.7.1 and 4.7.2), where discontinuous water courses have been transformed into continuously incised

Chapter 4 – Biodiversity and Habitats 85 channels with eroding banks (Brierley et al. 1999). Reaches of rivers in the predominantly forested Endrick and Mid Shoalhaven River sub-catchments are considered to be in Near Intact condition and have been identified as areas that should be conserved (Figures 4.7.2 and 4.7.3). High recovery potential reaches were found along some confined valley River Styles, especially in the Kangaroo Valley (Brierley et al. 1999) where the geomorphic condition of reaches may be easily rehabilitated at low cost through riparian vegetation.

Implications The River Styles assessments in the Shoalhaven catchment and the HNCMA area were conducted in the late 1990s and early 2000s, respectively. The assessments explicitly categorised the river reaches on the basis of the physical state of the riparian zone and river beds. On the whole, the Upper Coxs River sub-catchment and sub-catchments to the southwest of the Catchment area have been categorised as being predominantly Degraded or in Moderate condition, whereas those surrounding the main lakes and reservoirs to the east of the Catchment area have been categorised as being in Good or Near Intact condition. The River Styles assessments provide clear direction or benchmarks for prioritising river rehabilitation and conservation. They give highest priority for rehabilitation/management to River Styles that are closest to the Near Intact condition or are least represented. Lowest priority is given to those that are degraded and/or well represented. It is suggested that for the degraded streams, it is more expedient to wait for the streams to adjust to the prevailing environmental conditions and apply only minimal remediation such as planting and/or stock exclusion (Brierley et al. 1999). Any outcomes and recommendations from the River Styles assessments should be considered: i. at the sub-catchment scale given the broad nature of the assessments ii. in association with other indicators that are directly related to the outcomes of the River Styles assessment (e.g. fish and macroinvertebrate assessments) given the ‘age’ of the data set. For future audits, the River Styles assessment should be updated in consultation with the HNCMA and SRCMA who have access to a Land Management Database that contains data on remediation works and land use changes. The feasibility of improving the spatial resolution of the River Styles assessments in selected (priority) sub-catchments should also be determined if this indicator is to be used in future audits.

86 2010 Audit of the Sydney Drinking Water Catchment

Figure 4.7.1: River Styles in the Catchment

Figure 4.7.2: Condition of river reaches in the Catchment

Figure 4.7.3: Recovery potential of river reaches in the Catchment Table 4.7.1: Condition of river reaches in the Catchment

Near Sub-catchment Degraded Moderate Good intact Unknown Back Creek/Round Mountain Creek 0 94.7 0.1 0 5.2 Boro Creek 23.6 67.9 8.5 0 0 Braidwood Creek 0 48 29.7 20.4 2 Bungonia Creek 25.8 0 8 57 9.2 Endrick River 0 0 0 82.8 17.2 Jerrabattgulla Creek 0 8.9 60.7 23.9 6.5 Kangaroo River 31 8.8 16.4 32.1 11.7 Mid Shoalhaven River 0 0.9 37 46.2 16 Mongarlowe River 0 20.4 66.8 12.8 0 Nerrimunga River 49 26.4 22.4 0 2.2 Reedy Creek 24.9 22.7 33.6 18.3 0.5 Upper Shoalhaven River 0 3.4 12.5 84.1 0 Kowmung River 12.1 16.8 71 0.1 0 Lake Burragorang 0 0.1 9.3 90.6 0 Little River 0 0 0 100 0 Lower Coxs River 0 0 18.1 81.9 0 Mid Coxs River 1.4 26 27.7 44.9 0 Mulwaree River 35.7 64.3 0 0 0 Nattai River 1.6 0 0 98.4 0 Upper Coxs River 37.8 28.5 25.5 8.2 0 Upper Nepean River 0 3.2 45.5 51.3 0 Upper Wollondilly River 40.4 59.6 0 0 0 Werriberri Creek 0 84.6 0 15.4 0 Wingecarribee River 38.7 0 61.3 0 0 Wollondilly River 13.7 23.8 45.6 16.9 0 Source: HNCMA and SRCMA Note: Condition for each sub-catchment is characterised by the proportion (%) of reaches in the sub- catchment that are degraded, moderately degraded, good condition or near intact, as defined by Brierley and Fryirs (2005). No data was available for the Grose River (Cascade Creek, Lake Greaves, Woodford Creek) and Woronora sub-catchments.

Chapter 4 – Biodiversity and Habitats 87 Table 4.7.2: Recovery potential of river reaches in the Catchment

Strategically Very Sub-catchment Conserved managed high High Moderate Low Unknown Back Creek/Round Mountain Creek 0 0 n/a 0.1 94.7 0 5.2 Boro Creek 8.5 46.9 n/a 0 37.8 6.7 0 Braidwood Creek 50.7 0 n/a 0 48 0 1.2 Bungonia Creek 65.5 0 n/a 3.5 0 25.7 5.4 Endrick River 86 0 n/a 0 0 0 14 Jerrabattgulla Creek 24.8 0 n/a 75.2 0 0 0.1 Kangaroo River 41.6 1.5 n/a 11.6 4.5 35.6 5.1 Mid Shoalhaven River 57.9 0 n/a 25.5 0.9 0 15.7 Mongarlowe River 12.8 0 n/a 74.2 13 0 0 Nerrimunga River 0 0 n/a 22.4 26.7 50 0.8 Reedy Creek 18.3 0 n/a 7.2 49.3 24.3 0.9 Upper Shoalhaven River 87.5 0 n/a 12.5 0 0 0 Kowmung River n/a n/a 0.1 19.4 59.6 20.9 0 Lake Burragorang n/a n/a 90.6 7.3 0.1 2 0 Little River n/a n/a 100 0 0 0 0 Lower Coxs River n/a n/a 81.9 18.1 0 0 0 Mid Coxs River n/a n/a 54.9 0.1 22.7 22.3 0 Mulwaree River n/a n/a 0 0 64.3 35.7 0 Nattai River n/a n/a 98.4 0 0 1.6 0 Upper Coxs River n/a n/a 15.9 7.7 15.9 60.6 0 Upper Nepean River n/a n/a 51.3 4.7 43.9 0 0 Upper Wollondilly River n/a n/a 0 21.1 25.5 53.4 0 Werriberri Creek n/a n/a 15.4 0 84.6 0 0 Wingecarribee River n/a n/a 0 0 61.3 38.7 0 Wollondilly River n/a n/a 16.9 18.9 31.3 32.9 0 Source: HNCMA and SRCMA Note: Recovery potential for each sub-catchment is characterised by the proportion (%) of reaches in the sub-catchment that should be conserved, strategically managed, or have very high, high, moderate or low recovery potential. No data was available for the Grose River (Cascade Creek, Lake Greaves, Woodford Creek) and Woronora sub-catchments.

88 2010 Audit of the Sydney Drinking Water Catchment Chapter 5 Water Availability

Extraction of surface water and groundwater for human uses such as drinking water, agriculture and industry can place significant stress on the environment, as reduced volume and less variability of flow affect in-stream ecological processes. The major impacts of surface water extraction, and associated weirs and dams, include: • reduced volumes of water for the downstream environment • reduced ability of the environment to cope with natural drought periods • reduced variability of flow regimes • changes in the duration and timing of flow events • creation of large, standing water bodies which are ideal for algal blooms • degraded water quality • loss of habitat connectivity, including physically blocking fish passage • change in water temperatures. Groundwater is extracted for irrigation, industry and commercial purposes, but the majority of extraction is for stock and domestic purposes. Groundwater use can also increase in drought periods in response to reduced availability of surface waters. Groundwater extraction can modify the catchment hydrology by reducing water available for groundwater-dependent ecosystems such as wetlands, and by reducing base flow in surface streams (DECC 2007a). Environmental flows are those aspects of a stream flow regime that are important in maintaining the health and values of river-dependent ecosystems, including aquatic and riparian systems (Land and Water 2002). The volume, seasonality, velocity and rate of rise and fall of a flow can affect waterway health (Land and Water 2002). Climatic variability, including rainfall and drought periods, should be reflected in the management of flow regimes and water extraction to provide sufficient environmental flows (DECC 2007a). Bulk raw water is also often transferred in large amounts between areas and storages via rivers and streams in the Catchment as part of the SCA’s management of supplies to water filtration plants. These bulk water transfers can place significant stress on the geomorphology of rivers and streams and on aquatic ecosystems and habitats. The physical process of erosion and the rapid and extreme change in flow rate and height are the major impacting forces. SCA’s Water Management Licence restricts the changes in flow rate to limit impacts downstream.

5.1 Surface water flows

Background

Expansion of water extraction across NSW in the 20th century has placed most valleys at, or close to, the limit of sustainable water extraction (NOW 2010a). This has seen increasing competition between water users (towns, farmers, industries and

Chapter 5 – Water Availability 89 irrigators) for access to water. This has also placed pressure on the health and biological diversity of rivers and aquifers in the Catchment (NOW 2010a). Most of the demand for water from unregulated systems usually occurs at those times when stream flow is low. Low flows are essential for maintaining water quality, allowing passage over riffles for fish and other fauna to pools used for drought refuge, and maintaining those parts of aquatic ecosystems that are most productive (NOW 2010a). Although many streams will naturally stop flowing in dry times, it is the increased frequency and duration of drying as a result of extraction that has the potential to impact on stream ecosystems (NOW 2010a) To extract water from rivers and streams beyond ‘basic’ landholder rights, a water licence must be obtained from the NOW (formerly DWE and DNR) under the Water Act 1912 (or the Water Management Act 2000 for the Kangaroo River sub-catchment where a Water Sharing Plan has been gazetted) (NOW 2010a). These licences detail the purpose of extraction and the maximum annual extraction volume that is permitted under the water licence. From 1998 a landholder’s right to harvest the runoff in a dam without needing a licence, registration, fees or metering was limited to 10 per cent of the average regional rainfall runoff from the property (NOW 2010a). This is referred to as the ‘harvestable right’. The harvestable right enables the retention of runoff in farm dams. Farm dams require an access licence only when they: • are located on a 3rd-order (or greater) river, irrespective of the dam capacity or purpose • exceed the maximum harvestable right dam capacity for the property, or • are on a permanent (spring fed) 1st and 2nd order stream (NOW 2010a). The Water Act 1912 provides exemptions from licensing for dams constructed for the control or prevention of soil erosion, runoff detention or flood mitigation, dams that capture contaminated waters and dams on very small properties (DECC 2007a). In addition, licensed extraction of water occurs for a number of town water supplies. These supplies range between large storages to small direct river extractions. These supplies are administered through various local councils and major utilities such as the SCA. Local water utilities are managed by local councils. The Goulburn Mulwaree Council supplies the largest amount of water to households (NOW 2010a). The Goulburn Mulwaree Council extracts water from the Wollondilly River and Sooley Creek to supply water for towns including Goulburn and Marulan. Wingecarribee Shire Council extracts water from Wingecarribee River for towns in the southern highlands. Shoalhaven City Council draws water from the lower Shoalhaven River to supply Nowra and surrounding towns. Water is drawn from the upper Shoalhaven River by Palerang Council to supply water to Braidwood (NOW 2010a). While strictly not an extraction licence, Eraring Energy has an entitlement to interchange up to a maximum of 4021 ML at any time between Yarrunga and Fitzroy Falls, 880 ML at any time between Bendeela Pondage and Lake Yarrunga, and up to 10,000 ML between Lake Yarrunga and Fitzroy Falls in times of unusually high power demand or failure of generating stations in the state energy grid (NOW 2010a).

Water sharing plan Under the Water Management Act 2000 the sharing of water must protect the water source and its dependent ecosystems and must protect basic landholder rights (NOW 2010a). Sharing or extraction of water under any other right must not prejudice these. Therefore, sharing water to licensed water users is effectively the next priority for water sharing. Amongst licensed water users, priority is given to water utilities and

90 2010 Audit of the Sydney Drinking Water Catchment licensed stock and domestic use, ahead of commercial purposes such as irrigation and other industries. Water sharing plans provide a legal basis for sharing water between the environment and consumptive purposes (NOW 2010a). Water sharing plans are required to reserve water for the overall health of the river and to protect specific ecosystems that depend on river flows, such as wetlands, lakes, estuaries and floodplains. This share of water reserved for the environment is also intended to sustain the river system’s aquatic fauna and flora (NOW 2010a) NOW has just completed the exhibition of the Draft Water Sharing Plan for the Greater Metropolitan Region. The draft plan covers 79 management zones that are grouped into six water sources (the Shoalhaven River, the Illawarra Rivers, the Southern Sydney Rivers, the Northern Sydney Rivers, the Upper Nepean and Upstream Warragamba, and the Hawkesbury and Lower Nepean Rivers) (NOW 2010a). The draft plan focuses on: • environmental water rules – the share of the water reserved for the environment • access rules – which determine when extraction is allowed (for example above a set river flow rate) • dealing rules – which control the trade of water, both the transfer of share components of an access licence and assignment of water allocation between access licences, as well as changing the location for water extraction. In order to protect a proportion of very low flows for the benefit of the environment, the plan imposes new access restrictions on days when flows are low (NOW 2010a). This is achieved by establishing ‘cease-to-pump’ rules that describe when water must not be extracted, depending on the amount of flow in the river on any given day. Twenty nine unregulated management zones were identified as having high instream values (NOW 2010a). For these management zones, trading into the water source will be limited so that there is no increase in water entitlement, and in some cases trading aims to decrease entitlement (NOW 2010a). Where the instream values are at high risk from extraction, the cease-to-pump rule tends to be conservative (NOW 2010a). Detailed water use is not available in the unregulated rivers since there is not yet broad-scale metering in these water sources (NOW 2010a). NSW is exploring this issue through the Water Use Monitoring Program. In addition, through the NSW and Australian Government’s Hawkesbury–Nepean River Recovery Project, all surface water licences with an entitlement of greater than 10 ML across the catchment of the Hawkesbury and Nepean Rivers shall be metered (NOW 2010a). For surface water extraction, this audit examined: • the maximum permissible annual volume of surface water that can be extracted under water access licences in the Catchment • the long-term median flow and flow exceedance curve4 for gauging stations located throughout the Catchment.

4 In statistical terms, the empirical cumulative distribution function (see http://stat.ethz.ch/R-manual/R-devel/library/stats/html/ecdf.html).

Chapter 5 – Water Availability 91 Findings

Licensed allocations – general Based on the report cards accompanying the Draft Water Sharing Plan for the Greater Metropolitan Region unregulated river water sources (NOW 2010a), the total licensed extraction in the rivers and streams covered by the Catchment is close to 28,550 ML/year (see Tables 5.1.1 and 5.1.2, and Appendix E for a breakdown on a major river and river management zone basis). Table 5.1.1: Water entitlements (ML/year) from licensed water extractions in the Catchment5

Number of Total Catchment licences entitlement Hawkesbury– Nepean 367 19732.7 Woronora 2 62.9 Shoalhaven 124 8752 Total 473 28547.6

The largest entitlements are in the Upper Wollondilly (6574.2 ML/year), Lower Wollondilly (4179.2 ML/year), Lower Kangaroo River (3927 ML/year) and Werriberri Creek (2394.8 ML/year) management zones. The lowest entitlements occur in the Upper Nepean tributaries (5 ML/year), Bungonia Creek (50 ML/year) and Upper Woronora River (62.9 ML/year) management zones. There is no licensed water entitlement6 in the Mid Cataract River, Avon River, Cordeaux River, Pheasants Nest Weir to Nepean Dam, Boro Creek and Shoalhaven Gorge management zones. If the total entitlement is divided by the total catchment area involved, then the greatest allocation on an area basis (14.97 ML/annum.km2) occurs in the Werriberri Creek catchment. The next highest allocation on an area basis (8.89 ML/annum.km2) occurs in the combined Kangaroo River, Yarrunga Creek and Fitzroy Falls catchment (Lower Kangaroo River management zone in the water sharing plan). The lowest licensed allocation on an area basis is in the Corang and Endrick River catchments. Note that these numbers do not allow for varying rainfall across the Catchment (which will affect the amount of water that can be sustainably harvested in these catchments) or for allocations for major water utilities.

5 Hawkesbury–Nepean figure excludes Grose River licences which are assumed to be outside the Catchment. These figures also exclude SCA and other major and local water utility entitlements. 6 Although SCA transfers bulk water through some of these zones as part of the Upper Nepean Water Supply chain for Sydney’s drinking water supply, there is no licensed water entitlement.

92 2010 Audit of the Sydney Drinking Water Catchment Table 5.1.2: Total licensed entitlement by water sharing plan management zone

Total Water sharing plan Area entitlement Entitlement/area management zone (km2) (ML/annum) (ML/annum.km2) Werriberri Creek 160 2394.8 14.968 Lower Kangaroo River (Kangaroo River, Yarrunga Creek and Fitzroy Falls) 511 4542 8.888 Wollondilly River total (includes Upper and Lower Wollondilly Management Zones) 3369 10753.4 3.192 Wingecarribee total (includes Upper and Lower Wingecarribee management zones) 743 2036.6 2.741 Grose River (most if not all downstream of Catchment areas) 649 1582.8 2.439 Mulwaree River 759 1426 1.879 Mid Shoalhaven River 1068 1826 1.710 Dharabuladh 646 911.5 1.411 Upper Nepean (all zones) 1188 1273 1.072 Kedumba 158 157 0.994 Shoalhaven Gorge 853 806 0.945 Upper Shoalhaven River 573 527 0.920 Mongarlowe River 411 359 0.873 Reedy Creek 367 279 0.760 Wywandy 368 273.3 0.743 Nerrimunga River 476 282 0.592 Upper Woronora River 152 62.9 0.414 Jenolan River 393 132 0.336 Bungonia Creek 271 50 0.185 Kowmung River 825 151 0.183 Nattai Lake Burragorang (includes Nattai and Little River, and Burragorang zones) 1343 224.1 0.167 Corang and Endrick Rivers 491 81 0.165 Boro Creek 210 0 0.000 Source: Draft Metropolitan Water Sharing Plan Report Cards (NOW 2010b)

Licensed allocations – major and local water utilities The entitlement for major and local water utilities in the Catchment amounts to 1,016,443 ML/year (see Table 5.1.3 for a breakdown by water supply and utility). The SCA has the largest entitlement (975,000 ML/yr for all management zones). Of the local water utilities, Goulburn Mulwaree Council has the largest entitlement (5300 ML/year), drawing from the Upper and Lower Wollondilly River management zones.

Chapter 5 – Water Availability 93 Table 5.1.3: Water Entitlements (ML/year) for major and local water utilities

Entitlement Water supply Operator Management zone (ML/yr)

Local water utilities Greater Lithgow Wollangambee River Council Colo River 974 Wingecarribee River Wingecarribee Shire Lower Wingecarribee 2,920 Council River Wingecarribee Shire Nepean River Council Maguires Crossing 250 Goulburn Mulwaree Wollondilly River Council Upper Wollondilly River 5,100 Goulburn Mulwaree Wollondilly River Council Lower Wollondilly River 200 Upper Lachlan Wollondilly River Council Lower Wollondilly River 69 Wingecarribee Shire Medway Rivulet Council Lower Wingecarribee 2,920 Shoalhaven River Palerang Council Mid Shoalhaven River 360 Kangaroo River Shoalhaven Water Lower Kangaroo River 3,650 (City Council) Major water utilities Coxs River (by means of Delta Electricity Wywandy 25,000 Wallerawang Dam) Shoalhaven River Sydney Catchment Lower Kangaroo 317,000 Authority River/Shoalhaven River Gorge Nepean River and tributaries Sydney Catchment Upper Nepean River 620,000 Authority tributaries headwaters, Lake Burragorang, Pheasants Nest Weir to Nepean Dam, Mid Cataract River Sydney Catchment Grose River Authority Grose River 6,000 Sydney Catchment Woronora River Authority Upper Woronora River 32,000

Note: This table has been slightly modified from Table 4 of NOW (2010a)

Long-term flow records A summary of flows in the Catchment during the current audit period compared to longer-term statistics are included in Tables 5.1.4 and 5.1.5. Further details for individual gauging stations are available in the specific sub-catchment sections in Appendix C. Flow exceedance curves are included in Appendix F.

94 2010 Audit of the Sydney Drinking Water Catchment Hawkesbury–Nepean Catchment Table 5.1.4: Long-term median flow (ML/day) at gauging stations in the Hawkesbury– Nepean Catchment

Audit Long- 2007– median/ Station Date records term 2010 long-term number Site name commenced median median median 212233 Cataract River @ 16/03/1983 0 0 0.162# Broughtons Pass Weir 2122725 Mulwaree River @ 7/06/1990 0 0 0.178# The Towers 212011 Coxs River @ 28/05/1960 38.403 7.851 0.2043 Lithgow 212204 Nepean River @ 24/07/1986 50.829 11.102 0.218 Avon Dam Road 2122201 Goondarrin Ck @ 3/08/1991 1.675 0.453 0.270 Kemira D’Cast 2122711 Wollondilly River 17/08/1990 13.775 3.975 0.289 @ Murrays Flat 212271 Wollondilly River 2/01/1974 40.92 13.479 0.329 @ Golden Valley 212280 Nattai River @ The 7/07/1965 19.37 6.496 0.335 Causeway 212244 Werriberri Ck @ 01/06/1988 3.003 1.372 0.457 Werombi 212055 Neubecks Ck @ 7/12/1991 0.5 0.3 0.6 u/s Walwang 2122111 Avon River @ 29/03/1990 4.526 2.723 0.602 Summit Tank 2122052 Burke River @ 19/02/1990 11.03 7.673 0.696 Nepean Dam Inflow 212203 Nepean River @ 17/11/1983 0 0 0.702 Pheasants Nest 212250 Coxs River @ 2/11/1966 169.6 123.43 0.728 Kelpie Point 212042 Farmers Ck @ Mt 25/09/1980 15.959 12.578 0.788 Walker 2122801 Nattai River @ The 12/07/1990 5.275 4.205 0.797 Crags 2122051 Nepean River @ 18/02/1990 28.491 25.541 0.896 Nepean Dam Inflow 212274 Caalang Ck @ 27/11/1986 6.977 6.285 0.901 Maugers 212008 Coxs River @ 9/02/1951 12.292 11.239 0.914 Bathurst Rd 212260 Kowmung River @ 1/05/1968 128.77 118.816 0.923 Cedar Ford

Chapter 5 – Water Availability 95 Audit Long- 2007– median/ Station Date records term 2010 long-term number Site name commenced median median median 212045 Coxs River @ 2/01/1981 46.6 46.8 1.004 Island Hill 212016 Kedumba River @ 03/06/1990 19.381 19.763 1.020 Maxwells Crossing 212013 Megalong Ck @ 21/11/1968 5.056 5.199 1.028 Narrow Neck 212270 Wollondilly River 15/12/1961 231.71 241.73 1.043 @ Jooriland 212209 Nepean River @ 6/02/1970 35.609 37.177 1.044 McGuires Crossing 212231 Cataract River @ 9/11/1967 106.83 121.618 1.138 Jordans Crossing 212291 Grose River @ 1/11/1987 95.674 116.42 1.217 Burralow 2122512 Coxs River @ 1/05/1999 8.617 10.718 1.244 Glenroy Bridge 2122112 Flying Fox No3 27/06/1990 0.328 0.415 1.265 Creek @ Upper Avon 2122322 Loddon River @ 9/03/1990 4.955 6.456 1.303 Bulli Appin Road 212040 Kialla Creek @ 10/06/1979 3.625 5.306 1.464 Pomeroy 212221 Cordeaux River @ 18/07/1990 6.854 10.371 1.513 Cordeaux Weir 212058 Coxs River @ u/s 15/12/2000 16.571 25.75 1.554 Lake Lyell 212009 Wingecarribee 26/10/1989 45.28 114.67 2.532 River @ Greenstead 212272 Wingecarribee 22/08/1975 27.304 94.025 3.444 River @ Berrima 212031 Wingecarribee 7/06/1989 21.061 77.071 3.659 River @ Bong Bong Weir 212210 Avon River @ 27/06/1969 1.494 9.306 6.229 Avon Weir 212275 Wingecarribee 9/10/1996 10.378 70.253 6.770 River @ Sheepwash Bridge 2122809 Little River @ Fire 21/08/1990 5.504 NA NA Road W4I 2122341 Glenquarry Ck @ 6/04/2003 NA 1.203 NA Alcorns 2122996 Tonalli River @ 1/07/2003 NA 4.148 NA Fire Road W2 (Site No 2) # Means instead of medians used to calculate ratio. Long-term medians calculated on daily data from the date records commenced up to, and including, 30 June 2007.

96 2010 Audit of the Sydney Drinking Water Catchment Gauging sites in the Hawkesbury–Nepean Catchment (Table 5.1.4) where median flow during the current audit period was less than 50% of their historic median flow included: • Cataract River @ Broughtons Pass • Mulwaree River @ Towers • Coxs River @ Lithgow • Nepean River @ Avon Dam Road • Goondarin Creek @ Kemira Downcast • Wollondilly River @ Murrays Flat • Wollondilly River @ Golden Valley • Nattai River @ The Causeway • Werriberri Creek @ Werombi. This suggests a degree of hydrologic stress may exist in these areas which are the result of the combined effects of climate, water extraction and water management. Flow in the Cataract River at Broughtons Pass and Nepean River at Avon Dam Road over the current audit period reflect SCA requirements under their water management licence as well as decisions on transfers of water to balance storages and maintain drinking water supply. The recent decline in flows in the Werriberri Creek sub-catchment was particularly noticeable (Figure 5.1.1). This apparent decline in flow in Werriberri Creek requires further investigation to ascertain its cause(s).

Figure 5.1.1: Flow in Werriberri Creek at Werombi (Note log scale)

Recommendation 12: NOW should investigate the reasons behind the recent decline in flow in Werriberri Creek.

Chapter 5 – Water Availability 97 Gauging sites in the Hawkesbury–Nepean Catchment where median flow during the current audit period was more than 150% of their historic median flow included: • Cordeaux River at Cordeaux Weir • Coxs River upstream of Lake Lyell • Wingecarribee River @ Greenstead • Wingecarribee River @ Berrima • Wingecarribee River @ Bong Bong • Avon River @ Avon Weir • Wingecarribee River @ Sheepwash Bridge. Sites in the Cordeaux, Avon and Wingecarribee Rivers are influenced by bulk water transfers. The greatest increase in flows occurred in the Wingecarribee River at Sheepwash Bridge (downstream of Wingecarribee Dam) where the median flow during the current audit period was almost 7 times its historic level7. Changes to the flow regime at most of these sites have already occurred as a result of the current embargo on transfers from the Shoalhaven River catchment. Flows in the Coxs River upstream of Lake Lyell are influenced by Delta Electricity’s water management licence for environmental flow releases from Lake Wallace. The timing and frequency of releases from Lake Wallace may change in the future as a result of the current review of Delta Electricity’s Water Management Licence. Thirlmere Lakes During the current audit period, concerns were raised about declines in water levels in Thirlmere Lakes (see Figure 5.1.2). Environmental groups raised the possibility that these declines might be related to longwall mining adjacent to, but approximately 600–700 m away from the Lakes (ABC 20108). There is as yet little scientific evidence to substantiate this view, with rainfall records indicating a continuing dry period in these areas. Shallow groundwater levels have, however, declined by approximately 4m over some areas of Tahmoor colliery (Geoterra 2006; ACARP 2006). The Thirlmere Lakes National Park New Plan of Management (NPWS 1997) identified that the Lakes were nearly dry in the 1902 drought and almost completely dry in the drought of 1928. The Plan also noted evidence from recent research indicating that the lake levels had at some time in the past been at least 4 metres lower than their present levels (presumably the 1997 levels). The only gauging station in the Little River sub-catchment that the Auditor is aware of is the one located at Fire Road W4I. As described in the sub-catchment summary for Little River (Appendix C), this has not been providing flow data since June 2007 and the controversy surrounding the hydrology of Thirlmere Lakes provides added weight for the need to re-instate a permanent flow gauging station in the Little River sub- catchment. Given their national importance, a lack of detailed scientific knowledge of the natural variability in the hydrology of the system and the current controversy around water levels in Thirlmere Lakes, the Auditor considers a research program on the surface and groundwater hydrology of Thirlmere Lakes and its catchment to be highly desirable.

7 Data for Wingecarribee River @ Sheepwash Bridge goes back to 1996. 8 ABC 2010, Concerns mining drying-up historic Thirlmere Lakes. Posted 11 October 2010. www.abc.net.au/news/stories/2010/10/11/3034608.htm?site=sydney

98 2010 Audit of the Sydney Drinking Water Catchment

Figure 5.1.2: Werriberri Lake (part of the Thirlmere Lakes system) demonstrating very low water levels Source: DECCW – photo taken 16 October 2010

Recommendation 13: The SCA reinstate the flow gauging station in the Little River sub-catchment at Fire Road W4I.

Recommendation 14: DECCW, SCA, I&I and NOW establish a collaborative research program aimed at providing a better understanding of the surface water and groundwater hydrology of Thirlmere Lakes and its catchment.

Shoalhaven Catchment Table 5.1.5: Long-term median flow (ML/day) at gauging stations in the Shoalhaven Catchment

Audit Long 2007– median/ Station Date records term 2010 long-term number Site name commenced median median median 215240 Nerrimunga Ck 3/12/1994 0.081 0 0 @ Minshull Trig 215238 Reedy Ck @ 18/02/1995 5.19 0.137 0.026 Manar 215209 Shoalhaven 8/11/1973 215.5 50.881 0.236 River @ Mountview 215208 Shoalhaven 7/11/1973 324 96.406 0.298 River @ Hillview 215014 Bungonia Creek 15/04/1981 1.028 0.326 0.317 @ Bungonia

Chapter 5 – Water Availability 99 Audit Long 2007– median/ Station Date records term 2010 long-term number Site name commenced median median median 215207 Shoalhaven 15/07/1977 348.6 132.7 0.381 River @ Fossickers Flat 215210 Mongarlowe 8/11/1993 55.61 21.944 0.395 River @ Mongarlowe 215002 Shoalhaven 2/09/1914 177.5 79.16 0.446 River @ Warri 215239 Boro Ck @ 24/02/1994 4.191 2.026 0.483 Marlowe 215239 Boro Ck @ 24/02/1994 4.191 2.026 0.483 Marlowe 215215 Shoalhaven 20/07/1991 336.55 167.23 0.497 River @ D/S Tallowa Dam 215241 Shoalhaven 29/08/1994 11.708 5.93 0.506 River @ Bendoura 215008 Shoalhaven 18/09/1950 47.15 25.32 0.537 River @ Kadona 215004 Corang River @ 8/09/1924 25.44 17.12 0.673 Hockeys 215007 Mongarlowe 02/01/1950* 17.997 12.145 0.675 River @ Monga 215237 Gillamatong Ck 13/03/1994 3.635 2.833 0.779 215242 Corang River @ 3/12/1994 18.926 14.782 Meangora 0.781 215220 Kangaroo River 7/11/1973 166.29 152.769 @ Hampden Bridge 0.919 215233 Yarrunga Ck @ 15/11/1973 6.404 5.902 Wildes Meadow 0.922 215234 Yarrunga Ck @ 2/03/1983 11.986 13.8 Fitzroy Falls 1.151

Note: Long-term medians calculated on daily data from the date records commenced up to, and including, 30 June 2007.

The majority of gauging stations in the Shoalhaven Catchment (Table 5.1.5) had reduced median flows during the current audit period compared to their longer-term medians. Only the Kangaroo River at Hampden Bridge, Yarrunga Creek at Wildes Meadow and Yarrunga Creek at Fitzroy Falls had median flows close to their long- term median. Yarrunga Creek at Fitzroy Falls has managed environmental flow releases which are variable and equivalent to five-thirds of the inflow measured at Wildes Meadow. Gauging stations in the Shoalhaven catchment where median flow during the current audit period was much lower than their long-term median included:

100 2010 Audit of the Sydney Drinking Water Catchment • Nerrimunga Creek at Minshull trig9 • Reedy Creek at Manar • Shoalhaven River at Mountview • Shoalhaven River at Hillview.

Figure 5.1.2: Flow in Reedy Creek at Manar (note log scale)

The decline in flows in the Reedy Creek sub-catchment was particularly noticeable (Figure 5.1.2). This apparent long-term decline in flow in Reedy Creek requires further investigation to ascertain its cause(s).

Recommendation 15: NOW should investigate the reasons behind the apparent long-term decline in flow in Reedy Creek.

Implications The current audit period generally saw a return to periods of higher rainfall than had been experienced in previous audit periods for the Hawkesbury–Nepean River catchments. This was reflected in higher streamflows in some, but not all areas. Many areas in the Shoalhaven River catchment, however, still have much lower median flows than their long-term statistics. Exceptions to this are the catchments around Kangaroo River, Yarrunga Creek and Fitzroy Falls. The SCA found that the annual inflow to Tallowa Dam in the 2008–2009 period was actually lower than in any of the previous twelve years (SCA 2009e). Declines in flow compared to longer-term

9 Median flow for the current audit period was 0 ML/day at this site (i.e. it was not flowing on at least 50% of days).

Chapter 5 – Water Availability 101 statistics were particularly noticeable in Werriberri Creek and Reedy Creek. There was insufficient time during the current audit to relate observed changes and/or trends in flow back to varying rainfall patterns across the Catchment. The influence of water transfers can clearly be seen in the flow statistics with sites in the Wingecarribee and Upper Nepean being particularly affected. The greatest increase in flows occurred in the Wingecarribee River at Sheepwash Bridge (downstream of Wingecarribee Dam) where median flow during the current audit period was almost 7 times its historic long-term level. This difference had been even higher in the preceding three years (2004–2007), where the median flow at Sheepwash Bridge was almost 20 times its historic level (see Wingecarribee sub- catchment summary; Appendix C). Increases in flow due to water transfers have the potential to exert geomorphic stress on both the Wingecarribee and Upper Nepean River systems. During the previous audit period, the SCA made an assessment of the potential geomorphic impacts of these water transfers on the Wingecarribee and Upper Nepean Rivers (Patterson Britton & Partners 2006). This geomorphology impact assessment was based on an assessment of the altered operating regime and its effects on hydraulic conditions, in comparison to existing conditions, and on a site reconnaissance and review of current bed and bank conditions. Patterson Britton & Partners (2006) found the banks of the Wingecarribee River to be comprised of resistant sediments offering a stable river bank that would likely only experience erosion as a result of obstructions causing local scour or as a result of disturbance of the surface (e.g. cattle access). Bedrock dominated areas in the Wingecarribee River downstream of Berrima were also considered to offer a high resistance to erosion. Following the embargo on water transfers from the Shoalhaven catchment, the potential for any geomorphic stress due to water transfers in the Wingecarribee and Upper Nepean Rivers have now largely abated. They will however require further monitoring if/when water transfers are reinstated. Under the proposed Water Sharing Plan rules, transfers from the Shoalhaven will occur with increased frequency, but are likely to be of shorter duration than historic transfers. In accounting for the effects of extraction, the Auditor notes that the NOW management zones do not, in many cases, align with the Regional Environment Plan (REP) sub-catchment boundaries. Other important issues in relation to surface water flow are that: • there is evidence for declining trends in flow in some REP sub-catchments • some river gauges need replacement or upgrading • there are no gauges in some REP sub-catchments • there is no metering of licensed extractions in most areas. This complicates the assessment of pressure and state of surface water flows on an REP sub-catchment basis. The Auditor notes NOW’s assessment that most valleys are at or close to the limit of sustainable water extraction (NOW 2010a). It is up to NOW to finalise their Draft Water Sharing Plan for the Greater Metropolitan Region to formally establish the rules by which water is extracted from the Catchment.

Recommendation 16: NOW should finalise the Draft Water Sharing Plan for the Greater Metropolitan Region as soon as practicable.

102 2010 Audit of the Sydney Drinking Water Catchment 5.2 Environmental flows ‘Environmental flows’ is the term used to describe water released from dams as well as water that is protected from extraction by rules and extraction limits. Environmental flows support the needs of the environment to maintain ecosystem function by mimicking the elements of natural variability between high and low flows (NCC 2003). Flow regime is a key driver of aquatic ecosystem health. Changes in the flow regime can cause changes to river geomorphology, habitat and water quality and greatly influence the riverine biota. Alteration to the natural flow regimes of rivers and streams and their floodplains and wetlands is recognised as a major factor contributing to loss of biological diversity and ecological function in aquatic ecosystems and is also listed as a Key Threatening Process in Schedule 3 of the Threatened Species Conservation Act (NSW Scientific Committee 2002). The magnitude and timing of flows in many NSW rivers has been modified as a result of the demand from both urban and agricultural development. The harvesting of water through farm dams and river extractions and the construction of dams and weirs on NSW rivers has changed the frequency and timing of natural flows. This has contributed to an increase in periods of no flow and extremely low flow, degraded water quality, reduced riverine habitat, reduced flooding of riparian zones and wetlands, increased algal blooms and erosion of river channels (DECC 2007a). To ensure sufficient volumes of flow for the riverine environment, the amount of water extracted and the amount of water captured by dams must be managed. The SCA is required to release water from its storages for the downstream environment, in accordance with the requirements of its Water Management Licence. The current requirements under the Water Management Licence for releases from dams for environmental flows are a result of the Hawkesbury–Nepean River Management Forum Inquiry into the Hawkesbury-Nepean River system (HNRMF 2004). Water released from the Woronora, Warragamba and Tallowa Dams, and the Pheasants Nest and Broughtons Pass weirs, flows to rivers and streams outside the Catchment, while releases from Wingecarribee, Fitzroy Falls, Nepean, Avon, Cataract and Cordeaux Dams flow within the Catchment as examined by this audit. The bulk transfer of water through natural watercourses can also significantly affect ecosystems through high flow, rapid change in flow, prolonged flooding, and streambank erosion. In accordance with SCA’s Water Management Licence, bulk water transfers occur within the Catchment from Wingecarribee Reservoir through the Glenquarry Cut to the Nepean River in the Upper Nepean River sub-catchment, and into the Wingecarribee and Wollondilly Rivers sub-catchments to Lake Burragorang. This audit examined: • dams, weirs and other barriers to flow, in the Catchment • total volume of water released for the environment from SCA storages during the audit period • the management of bulk water transfers.

Chapter 5 – Water Availability 103 Findings

Dams, weirs and other barriers to flow Dams, weirs and barriers permanently alter the flow of rivers and streams, create a barrier to fish passage and affect water quality, particularly temperature and the movement of nutrients out of the sediment when the weir pool stratifies or destratifies, which can cause conditions suitable for algal blooms. The majority of weirs and barriers in the Catchment are located in the Upper Wollondilly River, Kangaroo River, Wingecarribee River, Werriberri Creek and Upper Coxs River sub- catchments and the upper section of the Bungonia Creek sub-catchment around Barbers Creek (DECC 2007a). During the current audit period a number of changes were made to many of the weirs and dams in the Catchment. In order to release new variable flows, additional outlets have been installed at each dam and water supply weir. These new outlets will allow for flows that better mimic the natural inflows into the dams (OHN and SCA undated). Fishways have been installed at Pheasants Nest Weir (Figure 5.2.1) and at other weirs further downstream to improve fish passage. A fish ‘lift’ has also been constructed at Tallowa Dam (see 4.2 Fish section for further details) to improve fish passage in the Shoalhaven River.

Figure 5.2.1: New fishway at Pheasants Nest Weir

104 2010 Audit of the Sydney Drinking Water Catchment Current environmental flow regimes The following catchment summary of environmental flow regime is based directly on the SCA’s description of environmental flows10 and the Draft Water Sharing Plan (NOW 2010a).

Warragamba system The SCA currently releases 33.3 million litres per day from Warragamba Dam into the Nepean River for environmental purposes. Under the Draft Water Sharing Plan for the Greater Metropolitan Region Unregulated River Water Sources a number of changes to the environmental flow regime are planned for Warragamba Dam (NOW 2010a). Following the commencement of the Replacement Flows Project the 43.3ML/day currently released from Warragamba Dam will be replaced by an equivalent average daily release from Sydney Water Corporation’s St Marys Recycled Water Plant to the Nepean River at Penrith. Ten ML/day will be available for licensed purposes with the balance protected for the environment (NOW 2010a). On commencement of the Replacement Flows Project, the NSW Government has agreed to an additional 5ML/day release from Warragamba Dam to dilute discharges from Wallacia STP to Warragamba River. In addition to the fixed 5ML/day release for dilution purposes, the NSW Government is proposing a seasonally varying release from Warragamba Dam to meet ‘consumptive purposes’ below the Dam of 25ML/day for the months November March (Summer) and 17 ML/day for the months April– November (Winter). NOW was seeking feedback on these proposals during the exhibition of the Draft Water Sharing Plan. The final decision on Warragamba environmental flows is scheduled to be made by 2015.

Shoalhaven system The SCA releases water from Tallowa Dam and Wingecarribee and Fitzroy Falls reservoirs to help improve the environmental health of the rivers downstream and sustain riparian rights. At Wingecarribee Reservoir, at least 3 million litres of water per day (ML/day) is released downstream for environmental purposes. At Tallowa Dam, daily variable flows for environmental purposes began on 15 July 2009. Environmental flows and improved movement of fish up and down the river were made possible by the installation of a new off-take at Tallowa Dam, a new spillway gate at the top of the dam which ensures the environmental flows are at a similar temperature to the downstream river, and a mechanical fish lift to allow native fish to move upstream and downstream. At times of low flows and depending on the season, all inflows to Tallowa Dam up to 371 ML/day are released to the downstream river. At times of higher flow, an additional 20 percent of inflows to Tallowa Dam are released to the downstream river. At Fitzroy Falls Reservoir, environmental release levels are linked to inflow rates measured at Wildes Meadow Creek.

Upper Nepean system The SCA introduced daily variable flows from the Upper Nepean dams and water supply weirs for environmental purposes from 1 July 2010. Improvements to weirs along the Hawkesbury–Nepean River help the new flows make it downstream, with

10 www.sca.nsw.gov.au/dams-and-water/environmental-flows

Chapter 5 – Water Availability 105 modified or replaced fishways to allow fish to move more freely up and down the river to breed. At times of low flow, inflows to the Upper Nepean dams and water supply weirs are released to the downstream river. Variable inflows of up to 20.1 ML/day are released from Nepean Dam, 6.8 ML/day from Avon Dam, 4.5 ML/day from Cordeaux Dam and 14.5 ML/day from Cataract Dam. These releases are passed through Pheasants Nest and Broughtons Pass weirs to the downstream river. Inflows from the catchments between the dams and weirs are also released from the weirs, including up to 4.4 ML/day from Pheasants Nest Weir and up to 4.5 ML/day from Broughtons Pass Weir. At times of higher flow, an additional 20 percent of inflows to each dam and water supply weir are released to the downstream rivers.

Woronora system The SCA introduced daily variable flows from Woronora Dam for environmental purposes from 15 July 2009. At times of low flows, all inflows up to 4.1 ML/day are released to the downstream river. At times of higher flow, an additional 20 percent of inflows to Woronora Dam are released to the downstream river.

Blue Mountains system The Blue Mountains system is comprised of six small reservoirs located high in the Catchment. Apart from overflows during periods of high rainfall, there are no current environmental releases from these dams. Almost 230,000 ML of water was released from the SCA dams and storages for environmental purposes during the current audit period (2007–2010; SCA data provided 2010). This is illustrated graphically for the individual storages in Figure 5.2.2.

Figure 5.2.2: Environmental flow releases from the SCA storages Source: SCA data provided 2010 and DECC (2007)

106 2010 Audit of the Sydney Drinking Water Catchment Bulk water transfers During the current audit period 202,347 ML were transferred from Wingecarribee Reservoir to Warragamba and 45,370 ML was transferred to Glenquarry Cut (SCA data provided 2010). These transfers were lower than in the previous 3-year period. The variation in volumes over the major period of transfers during the drought can be seen in Figures 5.2.3 and 5.2.4. There is currently an embargo of transfers from the Shoalhaven system which means that bulk water transfers are likely to remain at relatively low levels in these areas. During the 2009–2010 period 9405 ML were transferred from Fitzroy Falls to Wingecarribee. No transfers occurred from the Fish River to Upper Cascade Dam during 2009–2010. Water transfer rules are proposed to change under the Water Sharing Plan (see NOW 2010a).

Figure 5.2.3: Bulk water transfers in the Wingecarribee River and flow at Sheepwash Bridge (Stn. 212275)

Chapter 5 – Water Availability 107

Figure 5.2.4: Bulk water transfers to Glenquarry Cut and flow in Glenquarry Creek at Alcorns (Stn. 2122341)

Implications The SCA released almost 230,000 ML of water from its dams and storages for environmental purposes during the current audit period. This is assumed to have been of significant benefit to the downstream environment. Similar data is required for environmental flows at other major dams and storages in the Catchment (e.g. in the Upper Coxs and Upper Wollondilly sub-catchments), but were not available for the current audit. This data should be sourced and reported on in future audits. A number of changes were made to the dams and water supply weirs in the Catchment including additional outlets in order to release new variable flows. Fishways have also been constructed at Pheasants Nest Weir and at a number of other weirs in the Hawkesbury–Nepean River system. A fish ‘lift’ has been constructed at Tallowa Dam to improve fish passage in the Shoalhaven River. These changes are considered by the Auditor to be beneficial for the Hawkesbury–Nepean and Shoalhaven River systems. The Auditor notes a number of monitoring programs are already in place to assess the effectiveness of these major changes, but that these will require a longer period of time before their effectiveness can be adequately assessed. Greater details on environmental responses to these changes should be available to future audits. A moratorium on transfers from the Shoalhaven system is currently in place and this already has a major influence on flows in the Wingecarribee River in the future. Flows in the Wingecarribee catchment should return to more natural flow regimes (albeit still influenced by the Wingecarribee Reservoir regulation and drinking water supply to the Wingecarribee LGA). The Draft Water Sharing Plan for the Greater Metropolitan Region Unregulated River Water Sources includes details on proposed environmental flows from Warragamba Dam (with the final decision on Warragamba environmental flows scheduled to be made by 2015). The final environmental flow regime for Warragamba will need to be reported on in future audits.

108 2010 Audit of the Sydney Drinking Water Catchment 5.3 Groundwater availability Groundwater is derived from rain which percolates down through the soil or through fractures in rock, filling up the pores between sand grains or the fissures in rocks. Up to half of all rainfall may reach the water table and recharge groundwater systems. About 97 per cent of the world’s available freshwater lies underground (Boulton et al. 2003). Geological formations such as those composed of sand, sandstone and limestone which contain usable quantities of groundwater are called aquifers. The aquifer closest to the ground surface is called the shallow, or unconfined, aquifer (its upper surface is the water table) but there are also deeper, confined (sometimes called artesian) aquifers where the water is confined under pressure between relatively impervious layers (WRC 2003). Many surface water ecosystems in Australia are reliant on groundwater for baseflows, and exchanges between stream and groundwater along the course of channels (Boulton et al. 2003). In periods of low flow and drought, groundwater can assume greater importance to maintaining base flows in streams and wetlands. This also means that groundwater can have greater influence on water quality during drought conditions. The extraction of groundwater must also be managed as it can result in more saline water entering the aquifer, as well as reduce base flows to waterways. The extraction of groundwater requires a licence under the Water Act 1912. Extraction for irrigation, industry, recreation (e.g. golf courses) and commercial purposes is managed through renewable licences. Extraction for stock and domestic supply as a ‘basic landholder right’ is administered through a non-renewable (perpetual) licence. Applications for extractions of significant quantities of groundwater are required to be supported by an impact assessment. There is currently an embargo in place on all new groundwater bores in parts of the Wingecarribee River, Wollondilly River, Kangaroo River, Nattai River, Upper Nepean River, Werriberri Creek, Lake Burragorang and Lower Coxs River sub-catchments (DECC 2007a, NSW Government Gazette 2004, 2005, 2007a, 2007b). Under the embargoes, the processing of applications of all groundwater licences for the defined areas are prevented, with some exemptions for: • domestic, stock, farming, cultural, town water supply and monitoring purposes • those circumstances where a bore already exists and trading of entitlement is proposed, replacement of the bore is required, or conversion from a test to production licence application has been lodged within a specified timeframe. NOW is currently implementing a NSW Water Extraction Monitoring Policy. As a result of this policy all groundwater licensees, other than those for stock or domestic purposes, are required to install volume meters. However, there are currently limited data on groundwater extraction volumes for most groundwater licences in the Catchment.

Groundwater sharing Connections between surface and groundwater systems vary significantly between systems. For example, surface waters recharging alluvial aquifers may emerge again at a discharge point in the river within hours. In contrast water recharging aquifers of the Great Artesian Basin may not discharge for some tens of thousands of years. The connection characteristics need to be considered in linking surface water and groundwater planning, as often the same resource is being accessed by both surface and groundwater licence holders (NOW 2010c).

Chapter 5 – Water Availability 109 For the purposes of water sharing, NOW (2010c) has grouped aquifer types into four basic categories: • Porous rock aquifers found in rock formations such as sandstone or limestone. Groundwater occurs within the pore space in the rock matrix. • Fractured rock aquifers found in rock formations such as granite or basalt. Groundwater in these rocks occurs mainly within the fractures and joints. • Coastal sand aquifers, where groundwater is contained in the pore spaces in the unconsolidated sand sediments. • Alluvial aquifers, where groundwater is contained in the pore spaces in the unconsolidated floodplain material. The level of connectivity, the relative level of impact and the timing of connection have been considered in developing both the unregulated river and the associated groundwater sharing plan for the Greater Metropolitan Region. One of the key factors in determining the sustainable yield for various aquifers is the downstream values in associated streams (NOW 2010c). The Draft Groundwater Sharing Plan (NOW 2010c) used the following definitions: Long-term average annual extraction limit (LTAAEL) – LTAAEL is calculated as the recharge volume multiplied by the sustainability factor. The sustainability factor is determined using a risk assessment approach. Groundwater basic landholder rights (BLR) – The volume of groundwater (in ML/yr) that is set aside for basic landholder rights, that is, water used for domestic and stock purposes. Total licensed groundwater entitlement (TLGE ) – TLGE includes all access licences, including local water utilities, aquifer interference, stock and domestic access licences and general purpose (industrial, irrigation and recreation). It does not include: o unresolved water licence applications submitted during amnesty periods o licences that are yet to have a volume assigned to them through a volumetric conversion process o current aquifer interference activities that are yet to be assigned a volume. Unassigned water – The volume of water not currently allocated either as entitlements (licences) or other rights (i.e. BLR)

Findings Based on the report cards accompanying the Draft Groundwater Sharing Plan for the Hawkesbury–Nepean catchment sources (NOW 2010c), a summary of the long-term annual extraction limits, basic landholder rights and total licensed groundwater extractions for various groundwater sources are summarised in Table 5.3.1. The ‘Total’ column in Table 5.3.1 is the sum of the BLR, TLGE and Unassigned categories. In most cases the sum of these categories is the same as the LTAAEL. Exceptions to this are the Blue Mountains and Nepean groundwater sources. It is unclear from NOW’s documentation why these differences occur. The TLGE covered by the Sydney Basin groundwater sources and the Coxs and Goulburn fractured rock aquifers is close to 48,572 ML/year (see Table 5.3.1 for a breakdown on a major groundwater management source basis). These figures,

110 2010 Audit of the Sydney Drinking Water Catchment however, are likely to cover areas inside and outside of the Catchment. Groundwater extraction levels on a sub-catchment basis from these groundwater sources were not available for the current audit. Of the major groundwater sources likely to be in the Catchment, the Coxs River groundwater source has the highest percentage (40.48%) of its LTAAEL volume allocated to licensed extractions. This is followed by the Sydney Basin Nepean groundwater source which has 16.36% of its LTAAEL volume allocated to licensed extractions. The Coxs River fractured rock groundwater source has the lowest percentage (1.67%) of its LTAAEL volume allocated to licensed extractions, but also the lowest LTAAEL overall (6806 ML/annum).

Table 5.3.1: Groundwater volume and entitlements in identified groundwater sources

LTAAEL GW BLR TLGE Unassigned TLGE/ Groundwater (ML/annu (ML/ (ML/ (ML / Total (ML/ LTAAEL source m) annum) annum) annum) annum) (%) Coxs River fractured 6,806 179 113.5 6,513.50 6,806.00 1.67 rock groundwater source Goulburn fractured 53,074 3,114 3,149 46,811 53,074 5.93 rock groundwater source Sydney Basin Blue 7,039 421 137.7 3,335.30 3,894.00 1.96 Mountains groundwater source Sydney Basin 45,915 2,601 2,591.50 40,722.50 45,915.0 5.64 Central groundwater 0 source Sydney Basin Coxs 17,108 454 6,926 9,728 17,108 40.48 River groundwater source Sydney Basin 99,568 5,971 16,294 37,303 59,568 16.36 Nepean groundwater source3 Sydney Basin North 19,682 722 557 18,403 19,682 2.83 groundwater source Sydney Basin 21,103 1,623 15,923 3,557 21,103 75.45 Richmond groundwater source Sydney Basin South 69,892 2,098 2,880 64,914 69,892 4.12 groundwater source Source: NOW (2010c and report cards)

Groundwater bore licences The total number of licensed bores in each sub-catchment of the Catchment is summarised in Table 5.3.2 and Figure 5.3.1. Up until 30 June 2010, approximately 5000 licensed bores existed in the Catchment, with 476 new licences being issued during the current audit period. The majority of these are basic landholder rights bores. No information was available on the extraction levels from these bores.

Chapter 5 – Water Availability 111 Table 5.3.2: Number of groundwater bore licences in the Catchment

Existing Audit period Percentage Sub-catchment licences licences Total of total Endrick River 4 0 4 0.080 Jerrabattgulla Creek 5 1 6 0.120 Lake Burragorang 15 1 16 0.320 Back & Round Mountain Creek 14 2 16 0.320 Kowmung River 22 0 22 0.440 Mid Shoalhaven River 24 2 26 0.520 Mongarlowe River 23 4 27 0.540 Little River 26 1 27 0.540 Boro Creek 25 5 30 0.600 Woronora River 29 9 38 0.761 Nerrimunga Creek 57 15 72 1.441 Braidwood Creek 55 25 80 1.601 Reedy River 62 31 93 1.861 Werriberri Creek 115 5 120 2.402 Lower Coxs River 133 7 140 2.802 Upper Coxs River 110 34 144 2.882 Mid Coxs River 174 13 187 3.743 Upper Nepean River 173 15 188 3.763 Grose River 192 11 203 4.063 Bungonia Creek 177 43 220 4.404 Nattai River 193 28 221 4.424 Upper Wollondilly River 247 32 279 5.584 Mulwaree River 278 63 341 6.825 Kangaroo River 403 28 431 8.627 Wollondilly River 653 101 754 15.092 Wingecarribee River 1311 0 1311 26.241 Total 4520 476 4996 100

Note: Numbers in the above table exclude licences identified as being cancelled, abandoned, lapsed, refused, withdrawn or lodged. Where duplicates existed in the database for a licence, these were only counted once. This may lead to an underestimate of total licensed bores if there are multiple bores on the same licence. Source: NOW data 2010

The Wingecarribee River sub-catchment had the highest number of licensed bores (N=1311 or 26.2% of the total). No new bore licences were issued during the current audit period in the Wingecarribee River sub-catchment, presumably because of the embargo on new bores in this area. The Wollondilly River sub-catchment had the next highest number of licensed bores (N=754 or 15.1% of the total). One hundred and one bore licences were issued for the Wollondilly River sub-catchment during the current audit period. Only one licensed bore was identified in the Upper Shoalhaven River sub-catchment, however, this was identified as having ‘lapsed’ and is not included in Table 5.3.2. The Endrick River and Jerrabattgulla Creek sub-catchments had the next lowest number of licensed bores (4 and 6 respectively).

112 2010 Audit of the Sydney Drinking Water Catchment

Figure 5.3.1: Licensed groundwater bores in the Catchment

Source: NOW data 2010 Based on different data, the 2007 audit (DECC 2007a) identified 640 new licensed bores sunk in the Catchment over the period 1 July 2005 to 30 June 2007. This number was higher than the 476 new licences issued during the current audit period. Compared to the number of existing licences at the beginning of the current audit period (1 July 2007) the greatest increases in licensed groundwater bores have occurred in the Reedy Creek (50% increase), Braidwood Creek (45.5% increase), Woronora River (31% increase) and Upper Coxs River (30.9% increase) sub- catchments. Moderate increases (greater than 20%) in the number of bores licensed were also found in the Nerrimunga River, Bungonia Creek and Mulwaree River sub- catchments. These figures illustrate a continuing demand for groundwater in many areas of the Catchment.

Kangaloon Borefield study During the current audit period the SCA produced an environmental assessment that summarised the extensive groundwater studies carried out on the Kangaloon Borefield. The SCA had commissioned and completed more than 60 technical, scientific and environmental investigations on the groundwater source in the Kangaloon area and the local environment of the proposed borefield area. Two long pumping trials were completed in 2007 and early 2008 to simulate borefield extraction over extended periods and monitor the condition and response of surrounding ecosystems. These trials showed there was no impact on the neighbouring swamps, nearby springs or the adjacent river flows during pumping. In response to increases in water storages in the catchment dams and reservoirs the NSW Government decided to shelve construction of proposed borefields in the Southern Highlands and Western Sydney11.

Longwall mining impacts During the current audit period a number of impacts to groundwater aquifers have been noted as a result of longwall mining operations. Regional depressurisation/ fracturing leading to shallow groundwater level declines of between 3 and 10 m have been measured over a number of longwall operations (e.g. BHPBIC 2009, ACARP 2006, Aurecon 2009c). One of the main concerns with groundwater level declines at Baal Bone Mine was the potential for groundwater to be drained from the Coxs River Swamp (Long Swamp) into the shallow regional aquifer, since the groundwater level in the shallow regional aquifer was now below the level in the swamp, whereas prior to mining it was just above the swamp groundwater level (Aurecon 2009c). Monitoring is currently ongoing, but at this stage no decline has been observed in Long Swamp (Aurecon 2009c). Declines in perched aquifer levels in swamps are discussed further in Section 4.6.

Implications Embargoes remain in place on all new groundwater bores in parts of the Wingecarribee River, Wollondilly River, Kangaroo River, Nattai River, Upper Nepean River, Werriberri Creek, Lake Burragorang and Lower Coxs River sub-catchments. This may change once the Draft Groundwater Sharing Plan for the Hawkesbury– Nepean catchment sources is finalised. This could lead to an increased demand for groundwater extraction, particularly if there are restrictions on entry into (or reductions in entitlements in) surface water sharing management zones. Given the continuing number of new licences for groundwater bores being sought and

11 Nathan Rees MP Media Release Groundwater Borefields off the Agenda. 18 June 2008.

Chapter 5 – Water Availability 113 approved, close attention needs to be paid to the total volume of groundwater being extracted throughout the Catchment. While NOW (2010c) has defined groundwater sources for the Catchment, the exact boundaries of these sources and their degree of overlap with the sub-catchment boundaries remain unclear. It is also unclear what the degree of connectivity is between adjacent aquifers or their level of connectivity to surface waters. It is noted that the groundwater sources for the Shoalhaven River catchment are covered by the Goulburn Fractured Rock and Sydney Basin South Management Zones (NOW 2010c). Metering of groundwater extractions still needs to be implemented. As a result, detailed spatial and temporal data on groundwater extractions in the Catchment remains lacking. Where it has been monitored, groundwater levels have been found to decline in some areas subject to longwall mining. This is likely to continue, or even increase, with the recent expansion in mining proposals. Appropriate monitoring of groundwater is required for all such mining operations. There is a large knowledge gap in understanding the extent, connectivity and interaction between sub-surface aquifers (confined and unconfined), perched aquifers and surface waters in most areas of the Catchment. More intensive research in these areas would be of great benefit to the Catchment and help identify the current (and projected future) pressure on groundwater resources.

Recommendation 17: NOW and SCA undertake research aimed at understanding the extent, connectivity and interaction between sub-surface aquifers (confined and unconfined), perched aquifers and surface waters within the Catchment.

114 2010 Audit of the Sydney Drinking Water Catchment Chapter 6 Water Quality

Sydney’s drinking water supply is managed using a multiple barrier approach to control risks to water quality, including catchment management, storage management, delivery system management and treatment systems (NHMRC & NRMMC 2004; SCA 2005). Natural systems in the Catchment and around storages contribute to this multiple barrier approach by reducing risks to water quality. Many water supply authorities have tried to secure ecosystem processes by closing off, or in some way protecting, the hydrological catchments of their storages. The SCA has taken a similar approach through the Special Areas which comprise 370,000 hectares, or about a quarter of the total Catchment area (DECC 2007a). Special Areas are tracts of largely native vegetation in good condition around water storages and lands containing the SCA’s canals and pipelines. The Special Areas are particularly important as part of the multiple barrier approach to protecting water quality. They act as a buffer against nutrients and other pollutants for ecosystems that are in reasonably good condition and are near storages and bulk water off-take points. These barriers appear effective under low and moderate flow conditions when water can take several years to travel between the outer catchment and the dam wall. However, under periods of high flow, the barrier effect of the storage can break down and the capacity of the ecosystem in the remainder of the Catchment becomes critically important. This capacity is strongly dependent on the integrity and health of the ecosystems across the entire Catchment. Pressures on ecosystem health therefore need to be managed across the entire Catchment.

6.1 Ecosystem and raw water quality

Background

Ecosystem water quality Water quality in rivers and streams is largely a function of land use and catchment geology as well as in-stream processes. A wide range of human-related inputs to river systems can affect in-stream processes and can be detected by using water quality analyses. For example, high nutrient levels can stimulate algal blooms and toxic chemicals can severely affect aquatic plant and animal communities. Healthy ecosystems help generate and maintain good water quality. This audit examined 12 water quality parameters that can signal whether the pressures in the Catchment are impacting on the water quality required to maintain aquatic ecosystems. These parameters were assessed against the guideline values for ecosystem health in the Australian and New Zealand Environmental Conservation Council (ANZECC) and Agricultural and Resource Management Council of Australia and New Zealand (ARMCANZ) guidelines for Fresh and Marine Water Quality (ANZECC/ARMCANZ 2000) – referred to hereafter as the ‘ANZECC guidelines’. The ANZECC guidelines are applied to different ecosystem types. The ecosystem types present in the Catchment are upland rivers (>150m altitude) and freshwater lakes and reservoirs. Each sampled site in the Catchment was split into either an upland river or freshwater lake and reservoir site and assessed against the

Chapter 6 – Water Quality 115 corresponding ANZECC guidelines (Appendix G). The ANZECC approach also allows for the use of alternative guideline values where locally available data suggest that this is appropriate. The advantages of using the ANZECC guidelines and its associated approach are that it provides a quick methodology that identifies areas for further investigation. There are, however, limitations in the strict literal interpretation of the ANZECC levels to indicate ‘health’. The ANZECC guideline values should therefore be used as a trigger to indicate that investigation of exceedances are necessary and not that the exceedances automatically imply that the ecosystem is ‘unhealthy’. One of the clearest examples of this is the pH of water draining from upland swamps where the water is often slightly acidic (pH 5.5 to 6.5) and outside of the ANZECC guideline range for upland rivers (pH 6.5 to 7.5) as a result of natural processes. Water quality data was obtained from the SCA for long-term monitoring sites throughout the Catchment. Additional water quality data from a number of other sources (e.g. DECCW’s database, Delta Electricity compliance reports, Streamwatch sampling) were also obtained for the Coxs River catchment. These data were divided into 3-year periods for comparison with water quality data collected during the current audit period. Levels recorded for various parameters were then compared to the ANZECC guidelines for upland rivers or freshwater lakes and reservoirs (ANZECC/ARMCANZ 2000). Tables were produced which identified where the percentiles (minimum, 25th percentile, median, 80th percentile and maximum) at each site fell according to ANZECC/ARMCANZ trigger levels (ANZECC/ARMCANZ 2000, Tables 3.3.2 and 3.3.3 South-east Australia). The 12 water quality indicators considered in this assessment were: • physical indicators – turbidity (NTU), pH, conductivity (mS/cm) and dissolved oxygen (%) • metal indicators – total aluminium (Al) (mg/L) and total iron (Fe) (mg/L) • nutrient indicators – total nitrogen (µg/L), total phosphorus (µg/L), oxidised nitrogen (µg/L), ammonia (µg/L) and filtered phosphorus (µg/L) • algal indicators – chlorophyll a (µg/L). The ratings applied to each indicator were: • ‘extremely poor’ – when all samples exceeded the ANZECC guideline value for a parameter (i.e. the minimum value was greater than the ANZECC guideline value) • ‘very poor’ – when more than 75% of samples exceeded the ANZECC guideline value for a parameter • ‘poor’ – when more than 50% of samples exceeded the ANZECC guideline value for a parameter • ‘fair’ when more than 20% of samples exceeded the ANZECC guideline value for a parameter • ‘good’ when less than 20% of samples exceeded the ANZECC guideline value for a parameter • ‘very good’ .– when all samples were below the ANZECC guideline value for a parameter (i.e. the maximum value was less than the ANZECC guideline value). Colour coding was applied to these ratings according to that described in Table 6.1.1.

116 2010 Audit of the Sydney Drinking Water Catchment Table 6.1.1: Colour coding for water quality comparisons with ANZECC guidelines

Very Good No values > ANZECC guideline

Good Maximum > ANZECC guideline

Fair 80th Percentile > ANZECC guideline

Poor 50th Percentile > ANZECC guideline

Very Poor 25th Percentile > ANZECC guideline

Extremely Minimum > ANZECC guideline Poor

No data or percentiles not calculated due to small sample sizes

In all quantitative assessments of physico-chemical water quality, where values were given as less than the detection limit (

Findings

Ecosystem water quality A full list of the sites assessed, median indicator level, sample size and the ratings applied can be found in Appendix G. Selected water quality indicators measured during the current audit period are summarised according to their greater catchment boundaries in the following sections on a basin scale (e.g. Hawkesbury–Nepean, Woronora, Shoalhaven). A greater emphasis has been placed on nutrients, conductivity and chlorophyll a as indicators of more general eutrophication and/or increasing salinisation of waters. This is not, however, meant to reduce the importance of the other water quality indicators. The Auditor notes that for many potential water quality indicators (e.g. heavy metals in the Upper Coxs River sub- catchment) there is insufficient long-term data to provide a rigorous assessment of state or trend.

Chapter 6 – Water Quality 117 Hawkesbury–Nepean and Woronora catchments

Conductivity – river sites The highest median conductivity level recorded during the current audit period at sites with long-term monitoring data was in the section of the Coxs River downstream of Delta Electricity’s Blowdown Discharge to Marrangaroo Creek (1.6 mS/cm) (Table 6.1.2). High median conductivity levels were also recorded in the Coxs River downstream of Marrangaroo Creek, Mulwaree River at Towers Weir, Coxs River downstream of Lake Wallace to the Blowdown discharge and Wollondilly River at Murrays Flat. Low median conductivity levels were recorded in the Coxs River upstream of Kangaroo Creek, Marrangaroo Creek, Kowmung River and various sites in the Upper Nepean catchments.

Table 6.1.2: Median conductivity levels at river sites with long-term monitoring data

Median Median conductivity conductivity Site level (mS/cm) Site level (mS/cm) Coxs River D/S Blowdown to 1.6 Waratah Rivulet DS 0.1923 Marrangaroo Creek PUR Coxs River D/S Marrangaroo 1.081 Woronora River Inflow 0.143 Creek Mulwaree River at Towers 0.778 Coxs River at Kelpie 0.141 Weir Point Coxs River D/S Lake Wallace 0.751 River Lett 0.14 to Blowdown Wollondilly River at Murrays 0.6925 Little River at Fireroad 0.136 Flat W4I Coxs River D/S Sawyers 0.676 Wingecarribee River at 0.127 Swamp Creek to Pipers Flat Berrima Creek Coxs River below Lake Lyell to 0.506 Nepean River at Inflow 0.1045 Glenroy to Lake Nepean Neubecks Creek 0.445 Nepean River at 0.098 McGuires Crossing Pipers Flat Creek 0.442 Kedumba River at 0.075 Maxwells Crossing Gibbergunyah Creek at 0.363 Burke River at Inflow to 0.073 Mittagong STP Lake Nepean Nattai River at The Crags 0.3535 Kowmung River 0.0715 Nattai River at Smallwoods 0.303 Marrangaroo Creek 0.05 Crossing Wollondilly River at Golden 0.3 Coxs River U/S 0.04 Valley Kangaroo Creek Werriberri Creek at Werombi 0.2765 Hollander River Coxs River Downstream 0.261 Tuglow River Glenroy to Duddawarra Farmers Creek near Lake Lyell 0.242 Wingecarribee River at Sheepwash Bridge Wollondilly River at Joorilands 0.194 Waratah Rivulet Waratah Rivulet US PUR 0.193

118 2010 Audit of the Sydney Drinking Water Catchment Conductivity – reservoir sites The majority of reservoir sites had very low conductivities. The highest median conductivity level recorded during the current audit period in the reservoirs was in Lake Wallace (0.779 mS/cm; Table 6.1.3). Relatively high median conductivity levels were also recorded in Thompsons Creek Dam and Lake Lyell. No data on conductivity were available for Pejar and Sooley reservoirs.

Table 6.1.3: Median conductivity levels at reservoir sites with long-term monitoring data

Median conductivity Site level* (mS/cm) Lake Wallace 0.779 Thompsons Creek Dam 0.59 Lake Lyell 0.52 Lake Prospect @ Midlake 0.259 Lake Burragorang @ Wollondilly Arm 40km u/s Dam 0.176 Lake Burragorang @ Wollondilly Arm 23km u/s Dam 0.165 Lake Burragorang @ 500m u/s Dam Wall 0.164 Lake Burragorang @ 14km u/s Dam Wall 0.162 Lake Burragorang @ 9km u/s Coxs River 0.156 Lake Woronora @ Dam Wall 0.111 Wingecarribee Lake @ Outlet 0.088 Lake Cordeaux @ Dam Wall 0.088 Lake Nepean @ Aerator 2 0.085 Lake Cataract @ Dam Wall 0.081 Lake Nepean @ 300m u/s Dam Wall 0.08 Lake Avon @ Upper Avon Valve Chamber 0.074 Lake Avon @ Dam Wall 0.071 Lower Cascade Dam 0.066 Lake Avon @ 7km u/s Dam Wall 0.065 Top Cascade Dam 0.046 Greaves Creek Dam 0.019

* Colour coding in this table has been based on the ANZECC conductivity guideline level for upland rivers, as the value provided in the ANZECC guidelines for freshwater lakes and reservoirs (20–30 µS/cm equivalent to 0.02 – 0.03 mS/cm) is for Tasmanian lakes (ANZECC/ARMCANZ 2000). The Auditor considers the colour coding used here serves as a useful representation of localised conductivity levels in these freshwater lake systems and it enables a direct comparison with conductivity levels in the rivers that flow into these lakes and reservoirs.

Total nitrogen – river sites The highest median total nitrogen level recorded during the current audit period at sites with long-term monitoring data was in Gibbergunyah Creek at Mittagong STP (2.83 mg/L) (Table 6.1.4). This suggests that high levels of total nitrogen are being sourced from the Braemar STP and/or the upper catchment. The next highest median total nitrogen level recorded during the current audit period was recorded in Farmers Creek near Lake Lyell (median=1.9 mg/L). This suggests that high levels of total nitrogen are being sourced from the Lithgow STP and/or the Lithgow Township.

Chapter 6 – Water Quality 119 High median total nitrogen levels were also recorded in the Mulwaree River at Towers Weir, Coxs River downstream of Delta Electricity’s Blowdown to Marrangaroo Creek and Nattai River at The Crags. Low median total nitrogen levels were recorded in the Little River at Fireroad W4I and Marrangaroo Creek.

Table 6.1.4: Total nitrogen levels recorded at river sites with long-term monitoring Median total Median total nitrogen nitrogen Site (mg/L) Site (mg/L) Gibbergunyah Creek @ 2.83 Coxs River U/S Kangaroo 0.335 Mittagong STP Creek Farmers Creek near Lake Lyell 1.9 Pipers Flat Creek 0.3 Mulwaree River @ Towers 1.415 Nattai River @ Smallwoods 0.29 Weir Crossing Coxs River D/S Blowdown to 1.4 Neubecks Creek 0.28 Marrangaroo Creek Nattai River @ The Crags 0.98 Coxs River @ Kelpie Point 0.28 Coxs River below Lake Lyell to 0.9 Coxs River @ Kelpie Point 0.28 Glenroy Coxs River D/S Sawyers 0.8 Nepean River @ Inflow to 0.24 Swamp Creek to Pipers Flat Lake Nepean Creek Wollondilly River @ Golden 0.77 River Lett 0.21 Valley Coxs River D/S Lake Wallace 0.74 Burke River @ Inflow to 0.2 to Blowdown Lake Nepean Wollondilly River @ Murrays 0.72 Woronora River Inflow 0.19 Flat Coxs River D/S Marrangaroo 0.7 Marrangaroo Creek 0.1 Creek Wollondilly River @ Joorilands 0.6 Little River @ Fireroad W4I 0.1 Wingecarribee River @ 0.52 Berrima Coxs River Downstream 0.475 Hollander River Glenroy to Duddawarra Kedumba River @ Maxwells 0.43 Tuglow River Crossing Werriberri Creek @ Werombi 0.415 Wingecarribee River @ Sheepwash Bridge Kowmung River 0.4 Waratah Rivulet Nepean River @ McGuires 0.4 Crossing

Total nitrogen – reservoir sites The highest median total nitrogen level recorded during the current audit period in the reservoirs was in Lake Lyell (1.89 mg/L) (Table 6.1.5). The next highest median total nitrogen level recorded during the current audit period was recorded in Lake Wallace (median=0.7 mg/L). This suggests that high levels of total nitrogen are being sourced from the Upper Coxs and Farmers Creek sub-catchments. Relatively high median

120 2010 Audit of the Sydney Drinking Water Catchment total nitrogen levels were also recorded at Thompsons Creek Dam (0.65 mg/L). Low median total nitrogen levels were recorded in the Blue Mountains reservoirs, Lake Avon, Lake Cataract and Lake Woronora. No data on total nitrogen was available for Pejar and Sooley reservoirs.

Table 6.1.5: Total nitrogen levels recorded at reservoir sites with long-term monitoring

Median total nitrogen Site (mg/L)

Lake Lyell 1.89 Lake Walllace 0.7 Thompsons Ck Dam 0.65 Lake Nepean @ 300 m upstream of dam wall 0.31 Wingecarribee Lake @ Outlet 0.3 Lake Burragorang @ Wollondilly Arm 23 km upstream 0.3 of Dam Lake Burragorang @ Wollondilly Arm 40 km upstream 0.3 of Dam Lake Cordeaux @ Dam wall 0.295 Lake Burragorang @ 9 km upstream of Coxs River 0.29 Lake Burragorang @ 14 km upstream of dam wall 0.28 Lake Burragorang @ 500 m upstream of dam wall 0.27 Lower Cascade Dam 0.2 Lake Prospect @ Midlake 0.2 Lake Woronora @ Dam wall 0.2 Lake Cataract @ Dam wall 0.2 Lake Avon @ Dam wall 0.2 Lake Avon @ Upper Avon Valve Chamber 0.2 Lake Avon @ 7km upstream of dam wall 0.2 Top Cascade Dam 0.175 Greaves Creek Dam 0.13

Total phosphorus – river sites The highest median total phosphorus level recorded during the current audit period at sites with long-term monitoring data was in the Coxs River downstream of Lake Wallace to the Blowdown (0.4 mg/L) (Table 6.1.6). This suggests that high levels of total phosphorus are being sourced from Lake Wallace. The next highest median total phosphorus level recorded during the current audit period was recorded in Farmers Creek near Lake Lyell (median=0.115 mg/L). This suggests that high levels of total phosphorus are being sourced from the Lithgow STP and/or the Lithgow township. High median total phosphorus levels were also recorded at Mulwaree River at Towers Weir, Coxs River D/S Sawyers Swamp Creek to Pipers Flat Creek and Gibbergunyah Creek at Mittagong STP. Low median total phosphorus levels were recorded in the Upper Nepean sub-catchment streams, at Woronora River Inflow, Little River at Fireroad W4I and Nattai River at Smallwoods Crossing.

Chapter 6 – Water Quality 121 Table 6.1.6: Total phosphorus levels recorded at river sites with long-term monitoring

Median total Median total phosphorus phosphorus Site (mg/L) Site (mg/L) Coxs River D/S Lake Wallace to 0.4 Neubecks Creek 0.02 Blowdown Farmers Creek near Lake Lyell 0.115 Coxs River U/S Kangaroo 0.019 Creek Coxs River D/S Blowdown to 0.1 Werriberri Creek @ 0.018 Marrangaroo Creek Werombi Mulwaree River @ Towers Weir 0.0965 Kowmung River 0.013 Coxs River D/S Sawyers Swamp 0.09 River Lett 0.0125 Creek to Pipers Flat Creek Gibbergunyah Creek @ 0.09 Coxs River @ Kelpie Point 0.012 Mittagong STP Wollondilly River @ Murrays Flat 0.066 Nepean River @ McGuires 0.01 Crossing Coxs River D/S Marrangaroo 0.06 Marrangaroo Creek 0.0095 Creek Nattai River @ The Crags 0.05 Burke River @ Inflow to 0.009 Lake Nepean Coxs River below Lake Lyell to 0.04 Nattai River @ Smallwoods 0.005 Glenroy Crossing Rossi Weir 0.04 Little River @ Fireroad W4I 0.005 Wingecarribee River @ Berrima 0.036 Woronora River Inflow 0.005 Wollondilly River @ Golden 0.034 Nepean River @ Inflow to 0.0025 Valley Lake Nepean Coxs River Downstream Glenroy 0.0305 Hollander River to Duddawarra Pipers Flat Creek 0.03 Tuglow River Wollondilly River @ Joorilands 0.03 Wingecarribee River @ Sheepwash Bridge Kedumba River @ Maxwells 0.027 Waratah Rivulet Crossing

Total phosphorus – reservoir sites The highest median total phosphorus level recorded during the current audit period in the reservoirs was in Lake Lyell (0.1 mg/L) (Table 6.1.7). The next highest median total phosphorus level recorded during the current audit period was recorded in Lake Wallace (median=0.08 mg/L). This suggests that high levels of total phosphorus are being sourced from the Upper Coxs and Farmers Creek catchments with Lithgow STP and the Lithgow township in particular, potentially having an influence on total phosphorus in Lake Lyell. High median total phosphorus levels were also recorded in Pejar and Sooley Dams. Relatively high median total phosphorus levels were recorded in Lake Burragorang in the Wollondilly Arm 40 km upstream of Warragamba Dam and in Thompsons Creek Dam. Low median total phosphorus levels were recorded in the Blue Mountains reservoirs, Upper Nepean dams, Lake Woronora and other areas of Lake Burragorang.

122 2010 Audit of the Sydney Drinking Water Catchment Table 6.1.7: Total phosphorus levels recorded at reservoir sites with long-term monitoring

Median total Site phosphorus (mg/L)

Lake Lyell 0.1 Lake Wallace 0.08 Pejar Dam 0.04 Sooley Dam 0.04 Lake Burragorang @ Wollondilly Arm 40km 0.025 upstream of Dam Thompsons Ck Dam 0.02 Wingecarribee Lake @ Outlet 0.0075 Lower Cascade Dam 0.005 Greaves Creek Dam 0.005 Lake Burragorang @ 500m upstream of dam wall 0.005 Lake Burragorang @ 14km upstream of dam wall 0.005 Lake Burragorang @ 9km upstream of Coxs River 0.005 Lake Burragorang @ Wollondilly Arm 23km 0.005 upstream of Dam Lake Prospect @ Midlake 0.005 Lake Woronora @ dam wall 0.005 Lake Cataract @ dam wall 0.005 Lake Cordeaux @ dam wall 0.005 Lake Cordeaux @ Junction of Kentish Ck & 0.005 Cordeaux R Lake Cordeaux @ Goondarin Ck 0.005 Lake Avon @ dam wall 0.005 Top Cascade Dam 0.0025

Chlorophyll a – river sites Fewer data were available for chlorophyll a levels at most river sites in the Catchment. The highest median chlorophyll a level recorded during the current audit period at sites with long-term monitoring data was in the Wingecarribee River at Berrima (15.8 µg/L) (Table 6.1.8). High median chlorophyll a levels were also recorded at Mulwaree River at Towers Weir and the Wollondilly River at Joorilands. Low median chlorophyll a levels were recorded at the Woronora River Inflow, the Burke River Inflow to Lake Nepean, the Nepean River Inflow to Lake Nepean and in the Kedumba River at Maxwells Crossing.

Chapter 6 – Water Quality 123 Table 6.1.8: Chlorophyll a levels recorded at river sites with long-term monitoring

Median* Site chlorophyll a (µg/L) Wingecarribee River @ Berrima 15.8 Mulwaree River @ Towers Weir 10.45 Wollondilly River @ Joorilands 7.6 Wollondilly River @ Murrays Flat 4.45 Wollondilly River @ Golden Valley 3.25 Gibbergunyah Creek @ Mittagong STP 3.05 Werriberri Creek @ Werombi 2.7 Nattai River @ Smallwoods Crossing 2.35 Nattai River @ The Crags 1.9 Nepean River @ McGuires Crossing 1.9 Coxs River @ Kelpie Point 0.9 Kowmung River 0.7 Little River @ Fireroad W4I 0.6 Kedumba River @ Maxwells Crossing 0.4 Nepean River @ Inflow to Lake Nepean 0.4 Burke River @ Inflow to Lake Nepean 0.3 Woronora River Inflow 0.1

*Colour coding in this table has been based on ANZECC guideline levels for chlorophyll a in freshwater lakes and reservoirs and lowland rivers (ANZECC trigger level = 5 µg/L). The ANZECC guidelines do not provide a chlorophyll a trigger level for upland rivers because they recommend monitoring of periphyton rather than phytoplankton. The Auditor notes the ANZECC recommendation regarding chlorophyll a levels in upland rivers, but considers the colour coding used here to still be informative, enabling a direct comparison with chlorophyll a levels in the freshwater lake and reservoir systems into which these rivers flow.

Chlorophyll a – reservoir sites The highest median Chlorophyll a level recorded during the current audit period in the reservoirs was in Wingecarribee Lake at the Outlet (10.2 µg/L) (Table 6.1.9). Relatively high median chlorophyll a levels were also recorded in Lake Cordeaux at the Dam Wall, Lake Avon at the Upper Avon Valve Chamber and in Lake Burragorang 500m u/s Dam Wall. This latter result potentially reflects the Microcystis bloom present on Lake Burragorang throughout much of 2007. Low median Chlorophyll a levels were recorded in Lake Woronora at the Dam Wall and in the Blue Mountains dams.

124 2010 Audit of the Sydney Drinking Water Catchment Table 6.1.9: Chlorophyll a levels recorded at reservoir sites with long-term monitoring

Median Site chlorophyll a (µg/L) Wingecarribee Lake @ Outlet 10.2 Lake Cordeaux @ Dam Wall 6.55 Lake Avon @ Upper Avon Valve Chamber 5.8 Lake Burragorang @ 500m u/s Dam Wall 5.2 Lake Cataract @ Dam Wall 4.8 Lake Burragorang @ Wollondilly Arm 23km u/s Dam 4.1 Lake Avon @ 7km u/s Dam Wall 4.1 Lake Burragorang @ 14km u/s Dam Wall 4 Lake Burragorang @ 9km u/s Coxs River 3.9 Lake Nepean @ 300m u/s Dam Wall 3.65 Lake Lyell 3.6 Lake Avon @ Dam Wall 2.8 Lake Prospect @ Midlake 2.7 Thompsons Ck Dam 2 Lake Wallace 2 Top Cascade Dam 2 Lower Cascade Dam 1.9 Greaves Creek Dam 1.9 Lake Woronora @ Dam Wall 0.8

Shoalhaven Catchment

Conductivity – river sites The highest median conductivity level recorded during the current audit period at sites with long-term monitoring data was in Gillamatong Creek at Braidwood (0.384 mS/cm) (Table 6.1.10). This result potentially reflects inputs from Braidwood STP and township. All other median conductivity levels at sites with long-term monitoring data were low and within ANZECC guidelines. No recent data were available for Jembaicumbene Creek at Bendoura, Reedy Creek at Manar or Nerrimunga Creek at Minshull Trig.

Chapter 6 – Water Quality 125 Table 6.1.10: Conductivity levels recorded at river sites with long-term monitoring

Median conductivity Site level (mS/cm)

Gillamatong Creek @ Braidwood 0.384 Shoalhaven River @ Fossickers Flat 0.111 Shoalhaven River @ D/S Tallowa Dam 0.1065 Shoalhaven River @ Hillview 0.096 Kangaroo River @ Hampden Bridge 0.082 Shoalhaven River @ Mount View 0.076 Boro Creek @ Marlowe 0.074 Corang River 0.054 Mongarlowe River @ Mongarlowe 0.05 Jembaicumbene Creek @ Bendoura Reedy Creek @ Manar Nerrimunga Creek @ Minshull Trig

Conductivity – reservoir sites Conductivity levels in the Shoalhaven reservoirs were all relatively low (Table 6.1.11). Table 6.1.11: Conductivity levels recorded at reservoir sites with long-term monitoring Median* conductivity Site level (mS/cm) Lake Yarrunga @ Shoalhaven River 0.1 Lake Yarrunga @ 100 m from dam wall 0.0995 Lake Yarrunga @ Kangaroo River at Bendeela 0.099 Power Station Lake Yarrunga @ Kangaroo and Yarrunga Junction 0.096 Lake Yarrunga @ Kangaroo Arm Reed Island 0.094 Lake Fitzroy Falls @ Dam wall 0.093

*Colour coding in this table has been based on the ANZECC conductivity guideline level for upland rivers, as the value provided in the ANZECC guidelines (20–30 µS/cm equivalent to 0.02–0.03 mS/cm) is for Tasmanian lakes (ANZECC/ARMCANZ 2000). The Auditor considers the colour coding used here to provide a useful representation of localised conductivity levels in these freshwater lake systems and it enables a direct comparison with conductivity levels in the rivers that flow into these reservoirs.

Total nitrogen – river sites The highest median total nitrogen level recorded during the current audit period at sites with long-term monitoring data was in Gillamatong Creek at Braidwood (0.63 mg/L) (Table 6.1.12). This suggests that relatively high levels of total nitrogen are being sourced from the Braidwood STP and/or Braidwood township. Relatively high median total nitrogen levels were also recorded in the Kangaroo River at Hampden Bridge and Shoalhaven River at Mount View. Low median total nitrogen levels were recorded in the Corang River and Boro Creek. No recent data were available for Jembaicumbene Creek at Bendoura, Reedy Creek at Manar or Nerrimunga Creek at Minshull Trig.

126 2010 Audit of the Sydney Drinking Water Catchment Table 6.1.12: Total nitrogen levels recorded at river sites with long-term monitoring

Median total nitrogen Site (mg/L)

Gillamatong Creek @ Braidwood 0.63 Kangaroo River @ Hampden Bridge 0.575 Shoalhaven River @ Mount View 0.54 Shoalhaven River @ Fossickers Flat 0.4 Shoalhaven River @ D/S Tallowa Dam 0.38 Shoalhaven River @ Hillview 0.38 Mongarlowe River @ Mongarlowe 0.345 Boro Creek @ Marlowe 0.2 Corang River 0.2 Jembaicumbene Creek @ Bendoura Reedy Creek @ Manar Nerrimunga Creek @ Minshull Trig

Total nitrogen – reservoir sites The highest median total nitrogen level recorded during the current audit period in the Shoalhaven reservoirs was in Lake Yarrunga 100m from Dam Wall (0.31 mg/L; Table 6.1.13). Median total nitrogen levels at other sites in the Shoalhaven reservoirs were all very similar.

Table 6.1.13: Total nitrogen levels recorded at reservoir sites with long-term monitoring

Median total nitrogen Site (mg/L) Lake Yarrunga @ 100m from Dam Wall 0.31 Lake Fitzroy Falls @ Dam Wall 0.3 Lake Yarrunga @ Kangaroo and Yarrunga Jn. 0.3 Lake Yarrunga @ Shoalhaven River 0.3 Lake Yarrunga @ Kangaroo R at Bendeela PS 0.3 Lake Yarrunga @ Kangaroo Arm Reed Island 0.3

Total phosphorus – river sites The highest median total phosphorus level recorded during the current audit period at sites with long-term monitoring data was in Gillamatong Creek at Braidwood (0.0905 mg/L) (Table 6.1.14). This suggests that relatively high levels of total phosphorus may be being sourced from the Braidwood STP and/or Braidwood township. Relatively high median total phosphorus levels were also recorded in the Mongarlowe River at Mongarlowe, Shoalhaven River at Mount View and Shoalhaven River at Fossickers Flat. Low median total phosphorus levels were recorded in the Corang River and Shoalhaven River downstream of Tallowa Dam. No recent data were available for Jembaicumbene Creek at Bendoura, Reedy Creek at Manar or Nerrimunga Creek at Minshull Trig.

Chapter 6 – Water Quality 127 Table 6.1.14: Total phosphorus levels recorded at river sites with long-term monitoring

Median total Site phosphorus (mg/L) Gillamatong Creek @ Braidwood 0.0905 Kangaroo River @ Hampden Bridge 0.052 Mongarlowe River @ Mongarlowe 0.037 Shoalhaven River @ Mount View 0.036 Shoalhaven River @ Fossickers Flat 0.03 Shoalhaven River @ Hillview 0.021 Boro Creek @ Marlowe 0.02 Shoalhaven River @ D/S Tallowa Dam 0.005 Corang River 0.005 Jembaicumbene Creek @ Bendoura Reedy Creek @ Manar Nerrimunga Creek @ Minshull Trig

Total Phosphorus – reservoir sites The highest median total phosphorus level recorded during the current audit period in the Shoalhaven reservoirs was in Lake Yarrunga in the Kangaroo River Arm at Bendeela Pumping Station (0.013 mg/L; Table 6.1.15). Low median total phosphorus levels were recorded in Lake Fitzroy Falls at the Dam Wall and Lake Yarrunga 100m from the Dam Wall.

Table 6.1.15: Total phosphorus levels recorded at reservoir sites with long-term monitoring

Site Median total phosphorus (mg/L) Lake Yarrunga @ Kangaroo R at Bendeela PS 0.013 Lake Yarrunga @ Kangaroo Arm Reed Island 0.01 Lake Yarrunga @ Kangaroo and Yarrunga Junction 0.005 Lake Yarrunga @ Shoalhaven River 0.005 Lake Fitzroy Falls @ Dam Wall 0.005 Lake Yarrunga @ 100m from Dam Wall 0.005

Chlorophyll a – river sites Overall, median chlorophyll a levels in the rivers were relatively low. The highest median chlorophyll a level recorded during the current audit period at sites with long- term monitoring data was in the Shoalhaven River at Hillview (3.5 µg/L) (Table 6.1.16). On some occasions high levels (maximums ranging between 32 and 71.3 µg/L) have been recorded in Gillamatong Creek although the overall median chlorophyll a level was relatively low (2.55 µg/L). No recent data were available for Jembaicumbene Creek at Bendoura, Reedy Creek at Manar or Nerrimunga Creek at Minshull Trig.

128 2010 Audit of the Sydney Drinking Water Catchment Table 6.1.16: Chlorophyll a levels recorded at river sites with long-term monitoring

Median* chlorophyll a Site (µg/L) Shoalhaven River @ Hillview 3.5 Shoalhaven River downstream of Tallowa Dam 3.3 Boro Creek @ Marlowe 3 Shoalhaven River @ Fossickers Flat 2.7 Gillamatong Creek @ Braidwood 2.55 Shoalhaven River @ Mount View 1.7 Kangaroo River @ Hampden Bridge 1.6 Mongarlowe River @ Mongarlowe 1.1 Corang River 0.8 Jembaicumbene Creek @ Bendoura Reedy Creek @ Manar Nerrimunga Creek @ Minshull Trig

*Colour coding in this table has been based on ANZECC guideline levels for chlorophyll a in freshwater lakes and reservoirs and lowland rivers (ANZECC trigger level = 5 µg/L). The ANZECC guidelines do not provide a chlorophyll a trigger level for upland rivers because they recommend monitoring of periphyton rather than phytoplankton. The Auditor notes the ANZECC recommendation regarding chlorophyll a levels in upland rivers, but considers the colour coding used here to be informative, enabling a direct comparison with chlorophyll a levels in the freshwater lake and reservoir systems into which these rivers flow.

Chlorophyll a – reservoir sites The highest median chlorophyll a level recorded during the current audit period in the Shoalhaven reservoirs was in Fitzroy Falls Reservoir (11.1 µg/L) (Table 6.1.17). Relatively high median chlorophyll a levels were also recorded in the Kangaroo River arm of Lake Yarrunga (9.55–10.15 µg/L). Median chlorophyll a levels were also elevated at the other Lake Yarrunga sites (4.9–5.7 µg/L).

Table 6.1.17: Chlorophyll a levels recorded at reservoir sites with long-term monitoring

Median chlorophyll a Site (µg/L) Lake Fitzroy Falls @ dam wall 11.1 Lake Yarrunga @ Kangaroo Arm Reed Island 10.15 Lake Yarrunga @ Kangaroo River at Bendeela 9.55 Power Station Lake Yarrunga @ Kangaroo and Yarrunga 5.7 Junction Lake Yarrunga @ 100 m from Dam Wall 4.9 Lake Yarrunga @ Shoalhaven River 4.9

Chapter 6 – Water Quality 129 Implications

Water quality is variable across the catchment as a result of geology, land use and a variety of instream processes. The geomorphology of the catchments has also been significantly modified in many areas (e.g. by dams, weirs, streambank and gully erosion). A number of areas in the Catchment can be identified where water quality remains relatively poor when compared to ANZECC guidelines. The influence of STPs and urban centres on water quality is particularly noticeable. The influence of other licensed discharges on water quality is also important in some sub-catchments. This is particularly true for conductivity and metal levels downstream of power generation and mining discharges in the Upper Coxs River sub-catchment. The latter issues have already been discussed in Section 3.2. High algal biomass (as reflected by chlorophyll a levels) is identifiable at some river sites and in a number of the dams. Some of the dams and reservoirs in the Wingecarribee, Kangaroo River–Fitzroy Falls, Upper Coxs River and Upper Wollondilly River sub-catchments have both high nutrient levels and high algal biomass. Persistent algal blooms in Wingecarribee Reservoir, Fitzroy Falls Reservoir and the Kangaroo River Arm of Lake Yarrunga are discussed further in Section 6.3. Relative to the size of the catchment there are a low number of sites with long-term water quality monitoring data. The Auditor notes that some sub-catchments in the Shoalhaven River catchment have no current long-term water quality monitoring sites. This is the case for the sub-catchments of: • Back and Round Mountains Creek • Upper Shoalhaven River • Reedy Creek • Nerrimunga River • Endrick River • Jerrabattgulla Creek. This issue is discussed further in Section 6.4: Trend assessment. Generalisations from the limited number of long-term monitoring sites may also not necessarily provide an accurate description of the state of water quality in all the rivers and streams within that sub-catchment.

Raw water quality

Bulk raw water There are a number of water filtration plants (WFPs) in the Sydney drinking water system operated by Sydney Water Corporation and local councils. WFPs are also an important part of the multiple barrier approach to improve drinking water quality. The level of contaminants in raw water supplied to 10 of the WFPs is monitored by SCA to optimise the raw water quality supplied and to minimise treatment costs. Raw water in storages is not required to meet drinking water quality standards. However, the most cost effective provision of good drinking water is likely to be a balance between ensuring good quality raw water and the application of water treatment technologies at WFPs. Bulk water supplied by the SCA to WFP operators is expected to meet site-specific raw water quality requirements for each WFP. The requirements for the Prospect, Warragamba, Orchard Hills, Macarthur, Nepean, Illawarra, Woronora, Cascade and Greaves Creek WFPs are detailed in the SCA’s Bulk Water Supply Agreement

130 2010 Audit of the Sydney Drinking Water Catchment (BWSA) with Sydney Water Corporation. The SCA also has a BWSA with Wingecarribee Shire Council and Shoalhaven City Council (Kangaroo Valley WFP) for their WFPs (Table 6.1.18). The current audit examined the level of exceedance of raw water quality parameters with the BWSA requirements. These parameters were selected for their importance in the production of quality drinking water and in the effective operation of the WFPs. The Area Standard Unit (ASU) for algae indicates the potential for filtration blockage, and the measure is derived from cell count and average size for each species present.

Chapter 6 – Water Quality 131 Table 6.1.18: BWSA requirements Illawarra Illawarra Woronora Orchard Hills Nepean Warra- gamba Cascade Winge- carribee Kangaroo Valley Analyte WFP Prospect Macarthur 185-<265 125-<185 80-<125 <80

Site HMAC ML/d ML/d ML/d ML/d IWF HWO1 HNE HWA1, HCS code PWFP10 1 demand demand demand demand PR -A HBR1 1 HWA2 R HWI1 HKV1 min 0 0 0 0 0 0 0 0 0 0 0 0 0 Turbidity (NTU) max 40 10 25 50 60 10 10 40 150 40 15 40 20 min 0 0 0 0 0 0 0 0 0 0 0 0 0 True Colour at 400nm max 60 40 40 40 40 50 70 60 60 60 60 70 70 min 0 0 0 0 0 0 0 0 0 0 0 0 0 Iron (total) max 3.5 0.6 0.8 1.1 1.3 1.1 1 3.5 5 3.5 3 1.1 1.1 min 0 0 0 0 0 0 0 0 0 0 0 Manganese (total) max 1.4 0.2 0.25 0.3 0.35 0.4 0.1 1.4 1.5 1.4 0.3 min 0 0 0 0 0 0 0 0 0 0 0 Aluminium (total) max 2.6 0.4 0.5 0.75 0.95 1.4 0.4 2.6 1 2.6 0.2 min 25 6 6 6 6 0 2 25 2 25 0 0 0 Hardness (mg/L CaCO3) max 70 30 32.2 32.2 32.2 30 30 70 35 70 40 36.5 36.5 min 15 0 0 0 0 0 0 15 0.5 15 0 0 0 Alkalinity (mg/L CaCO3) max 60 15 15 15 15 10 15 60 25 60 30 29 29 min 6.3 5.7 5.7 5.7 5.7 6.2 5.1 6.3 4.8 6.3 6 6.5 6.5 pH units max 7.9 7.7 7.7 7.7 7.7 7.2 7.5 7.9 7.7 7.9 7.9 8.5 8.5 min 10 8 8 8 8 10 10 10 10 10 10 Temperature (deg C) max 25 25 25 25 25 25 25 25 25 25 25 min 0 0 0 0 0 0 0 0 0 0 0 0 0 Algae (ASU) max 1000 100 100 500 500 5000 5000 2000 2000 2000 2000 5000 5000 min 0 0 Algae (toxigenic cells) max 6500 6500 min 0 Algae biovolume (mm3/L) max 4 min 0 0 Toxicity (µg/L Microcystin LR) max 0.7 1.3

Source: SCA data 2010 Note: Guidelines limits are from the 2008–09 period (the most recent BWSA requirements that was available to the Auditor)

132 2010 Audit of the Sydney Drinking Water Catchment Pesticides and synthetic organic compounds A pesticide is any substance or mixture of substance used to destroy, suppress or alter the life cycle of any pest (SCA 2009f). Pesticides are used widely throughout the Catchment for a variety of uses (e.g. as herbicides, insecticides, miticides, acaricides, fungicides, rodenticides, algacides, growth regulators etc). Pesticides must be registered by the Australian Pesticides and Veterinary Medicines Authority (APVMA) before they can be manufactured, supplied sold or used. The Pesticides Act 1999 regulates the use of pesticides after sale with the focus on protecting health, the environment, property and trade while safeguarding responsible pesticide use (SCA 2009f). DECCW enforces the proper use of all pesticides in NSW after the point of sale. Values for pesticides have been divided into two categories in the Australian Drinking Water Guidelines (ADWG) (NHMRC & NRMMC 2004) – guideline values and health values. Guideline values are intended for use by regulatory authorities for surveillance and enforcement purposes. They provide a mechanism to measure compliance with approved label directions. For pesticides that are not approved for use in water or water catchment areas, the guideline value is set at or about the limit of determination (LOD). Where a pesticide is approved for use in water or water catchment areas, the guideline value is set at a level that is consistent with good water management practice and that would not result in any significant risk to the health of the consumer over a lifetime of consumption (NHMRC & NRMMC 2004). Health values are intended for use by health authorities in managing the health risks associated with inadvertent exposure, such as a spill or misuse of a pesticide. The values are derived from the acceptable daily intake (ADI) and set at about 10 percent of the ADI for an adult weight of 70 kg for a daily water consumption of 2 litres. The health values are very conservative, include a range of safety factors and always err on the side of safety (NHMRC & NRMMC 2004). The detection of pesticides and other synthetic organic compounds (SOCs) in raw water was also considered in the current audit.

Findings

Bulk raw water Exceedances of BWSA requirements (see Table 6.1.18) are summarised in Table 6.1.19. The Auditor notes that the BWSA levels have changed at some WFPs a number of times over the last few years (and audit periods). It is also noted that Macarthur WFP BWSA levels now vary according to demand.

Chapter 6 – Water Quality 133 Table 6.1.19: Exceedance of BWSA (2008–09) levels at each WFP during the current audit period

WFP/ Sample Parameter Hardness ASU Temperature Alkalinity Iron size HBR1 0 0 0 0 0 27 HWA1/ HWA2 0 0 0 0 0 27 PWFP10 5 1 0 0 0 26 HCSR 0 0 5 0 0 31 IWFP 5 0 0 0 0 28 HWI1 4 0 0 0 0 43 HWO1A 1 0 0 0 0 26 HNE1 0 0 1 0 0 14 HKV1 1 0 0 1 2 27 HMAC 0 0 0 0 0 27 The exceedances detailed in Table 6.1.19 are for water delivered over the current audit period (1/7/07–30/6/10) with respect to the latest (2008–09) BWSA requirements provided to the Auditor. From Table 6.1.19 it can be seen that the majority of exceedances were for total hardness where exceedances occurred at Prospect, Illawarra, Wingecarribee, Woronora and Kangaroo Valley WFPs. Cascade WFP recorded 5 exceedances for temperature and Nepean WFP recorded 1 exceedance for temperature, all of which were related to colder water temperatures occurring during winter months. Prospect WFP recorded one high ASU level (1050) in November 2007. Kangaroo Valley WFP recorded 2 exceedances for iron. Orchard Hills, Warragamba and Macarthur WFPs recorded no exceedances (of the most recent (2008–09) BWSA requirements) over the current audit period.

Pesticides and synthetic organic compounds The SCA tests for a range of pesticide and other compounds in raw waters at the inflow to the WFPs. In 2009 they reported on a screening level risk assessment of pesticides and SOCs in the Catchment (SCA 2009f). Evaluation of monitoring data showed that no pesticide or SOC exceeded the Australian Drinking Water Guideline (NHMRC & NRMMC 2004) Health Values during the period January 2000 to June 2008. There were a total of 87 detections of pesticides with only three (3) detections found to be above the ADWG (2004) Guideline Value. There were, however, limited SOC monitoring data as these chemicals are not routinely monitored by the SCA. The overall risk assessment concluded that of the pesticides assessed, all were a low risk, with the exception of Triclopyr, which was assessed as a medium level risk of occurring at elevated levels in the raw water supply. The majority of SOCs were rated as having a low overall risk. Five were classified as medium risk: benzene; 1,2- dichloroethane; 1,2 dichloroethene; hexachlorobutadiene; and vinyl chloride. The Auditor reviewed the pesticide monitoring data at a number of inflows to WFPs and found that detections were indeed rare in most cases. Very low-level detections of hexazinone were, however, noted a number of times in raw water at the inflow to Cascade WFP12 (HCSR). Very low-level detections of triclopyr were noted a number of times in raw water at the inflow to Wingecarribee WFP (HWI1).

12 It should be noted here that at times Upper Cascade Dam may also receive some of its water from the Fish River Scheme, which originates at Oberon (SCA 2002).

134 2010 Audit of the Sydney Drinking Water Catchment Implications The majority of water quality analytes measured in the raw water met the (2008–09) BWSA requirements. Because of the changing BWSA levels and audit periods (from 2 years to 3 years) it is not considered informative to compare the current number of exceedances with exceedances in past audit periods. What is perhaps more informative is a trend analysis for the water quality parameters themselves over time. This is discussed further in Section 6.4 (Trend assessment13). The SCA should continue to focus not just on BWSA exceedances but trends in raw water quality, particularly where they are close to BWSA levels and where an increasing trend could foreshadow exceedance of BWSA requirements in the future. During the current audit period, none of the pesticide or SOC levels exceeded (or were even close to) the ADWG (NHMRC and NRMMC 2004) Health Guidelines. Very low-level detections of hexazinone were noted a number of times in raw water at the inflow to Cascade WFP and very low-level detections of triclopyr were noted a number of times in raw water at the inflow to Wingecarribee WFP. It is emphasised here that this is before water treatment processes are applied. The SCA is not alone in having such chemicals detected in their raw source water, with hexazinone recently detected in the Derwent River, Hobart (ABC 2009). Hexazinone has also been detected in raw source water and/or groundwater from other areas of Australia and overseas (e.g. DNRMQ 2002, Thornton 2006). This suggests to the Auditor that a catchment survey of pesticide usage in these specific catchments may be useful in understanding pesticide application practices within these catchments. This may also prove useful in educating landholders and contractors on best management practices for pesticide application, highlighting their potential to be transported to the drinking water supply.

Recommendation 18: The SCA undertake a targeted survey of pesticide usage and application in the catchments of Cascade Dam and Wingecarribee Reservoir.

Pathogens Giardia and some species of Cryptosporidium can cause intestinal infections in humans. These pathogenic micro-organisms are transmitted between humans by means of oocysts or cysts in excreted faecal material. Consumption of water containing oocysts/cysts is the principal method of contracting an infection (Braideck and Karlin 1985). Hypothetically one viable oocyst/cyst is capable of initiating an infection response, however, usually a much larger number of oocysts/cysts need to be ingested before the infection response is initiated (eg Teunis et al. 2002a, 2002b). Sources of these micro-organisms in the Catchment include STPs, unsewered areas with no or poorly performing on-site systems, humans, and native and domestic animals. Juvenile cattle and pigs, and adult and juvenile sheep have been found to shed the most Cryptosporidium. Native animals such as kangaroos shed lower levels of Cryptosporidium than domestic animals (CRCWQT 2007a). There is the potential for large amounts of pathogenic material, including Cryptosporidium and Giardia, to be mobilised during storm events to reach creeks, rivers and water storages. Cryptosporidium oocysts show relatively high mobilisation

13 Detailed trend analyses still need to be undertaken for the inflows to the water filtration plants.

Chapter 6 – Water Quality 135 rates across land surfaces during rain events as well as moving as single colloidal entities within rivers and reservoirs (CRCWQT 2007a). They can potentially move through even the largest reservoirs within relatively short periods of time (CRCWQT, 2007b). As a result, many water authorities in Australia (including the SCA) are actively engaged in research programs which look at the fate and transport of pathogens in their catchments. The current audit examined the incidence of DAPI (4’, 6-diamidino-2-phenylindole) positive Cryptosporidium oocysts and Giardia cysts in the Catchment during the current audit period. Identification of DAPI positive oocysts/cysts was undertaken using the DAPI staining technique that identifies the presence of intact characteristic internal structures. While not completely definitive for the presence of human-infective Cryptosporidium and Giardia, DAPI staining does differentiate clearly between oocysts/cysts with intact internal structural characteristics and other material.

Findings Tables 6.1.20 and 6.1.21 summarise the results of monitoring for DAPI positive Cryptosporidium and Giardia in the Catchment. During the current audit period the most frequent detections of Cryptosporidium and Giardia were in Gibbergunyah Creek downstream of Mittagong (Braemar) STP, Werriberri Creek at Werombi and the Kedumba River at Maxwells Crossing (Table 6.1.20). Low levels of DAPI positive Cryptosporidium and Giardia were also found at some of the inflows to the Water Filtration Plants, particularly in composite samples at Prospect WFP (Table 6.1.21). These findings are similar to the findings in the previous audit (DECC 2007a). The previous audit (DECC 2007a) recommended that the SCA investigate the causes of the continuing presence of pathogens in the Nattai River, Wollondilly River, Mid Coxs River and Werriberri Creek sub-catchments. In response to this recommendation, the SCA undertook some detailed assessments of Cryptosporidium and Giardia in Gibbergunyah Creek and other areas. A summary of the SCA’s findings is included in the case study below.

136 2010 Audit of the Sydney Drinking Water Catchment Table 6.1.20: Cryptosporidium and Giardia detections in the Catchment, 1 July 2007–22 July 2010

DAPI(+)ve samples Number of IFA- High Medium Low Site tested code Station samples Crypto Giardia Crypto Giardia Crypto Giardia Coxs River @ E083 Kelpie Point 41 0 0 0 0 1 0 Kowmung River @ Cedar E130 Ford 46 0 0 0 0 0 1 Kedumba River @ Maxwells E157 Crossing 48 0 0 0 0 3 3 Gibbergunyah Creek @ E203 Mittagong STP 102 1 1 17 24 26 30 Nattai River @ Smallwoods E210 Crossing 36 0 0 0 0 0 0 Little River @ E243 Fire Road W4I 38 0 0 0 0 2 0 Wollondilly River @ E488 Jooriland 48 0 0 0 0 1 3 Werriberri Creek @ E531 Werombi 177 0 0 0 1 14 6 Total 536 1 1 17 25 47 43 Source: SCA data 2010 High > 1000 cysts or oocysts per 100 L of sample Medium > 100 < 1000 cysts or oocysts per 100 L of sample Low < 100 cysts or oocysts per 100 L of sample

Chapter 6 – Water Quality 137 Table 6.1.21: Cryptosporidium and Giardia levels in the bulk delivery system, 1 July 2007–22 July 2010

DAPI(+)ve samples Number of IFA- High Medium Low Site tested code Station samples Crypto Giardia Crypto Giardia Crypto Giardia Lake DWA2 Burragorang 943 0 0 0 0 2 0 Macarthur WFP MACSP1 @ Inlet 124 0 0 0 0 6 1 Lake Prospect @ RPR1 Midlake – RPR1 309 0 0 0 0 2 0 Lake Prospect @ RPR6 Inlet to RWPS 101 0 0 0 0 0 0 Composite HWP1–1/HWP1– COMP14 2/HPR1/PWFP10 493 0 0 0 0 30 2 Composite HNE1/IWFP- R/HWO1- COMP16 A/HCSR 121 0 0 0 0 3 1 Wingecarribee DWI1 Reservoir –DWI1 158 0 0 0 0 1 0 Total 2249 0 0 0 0 44 4 Source: SCA data 2010 High > 1000 cysts or oocysts per 100 L of sample Medium > 100 < 1000 cysts or oocysts per 100 L of sample Low < 100 cysts or oocysts per 100 L of sample

Case study Cryptosporidium detections in Gibbergunyah Creek Gibbergunyah Creek @ Mittagong STP has had a history of elevated Cryptosporidium numbers at monitoring site E203. This site is on the confluence of Gibbergunyah Creek and Ironmines Creek and is approximately 35 m downstream of where Chinamans Creek enters Gibbergunyah Creek. The site is also approximately 400 m downstream of the discharge point for Braemar STP that serves the town of Mittagong. The discharge point is located on Ironmines Creek. There is also a mushroom factory a few hundred metres upstream of E203. Two studies were undertaken during 2009–10 which have shed some light on this issue: • An investigation was conducted by the SCA in June 2009 into the local conditions and variability of Cryptosporidium and Giardia detections in the Gibbergunyah Creek. • The SCA contracted the University of NSW (UNSW) to undertake a quantitative pathogen risk assessment from STPs. The study included a specific assessment of the ability of the Braemar STP to inactivate Cryptosporidium and Giardia.

138 2010 Audit of the Sydney Drinking Water Catchment What is the source of the Cryptosporidium oocysts observed at E203? The SCA investigation indicated that the primary, although not necessarily exclusive, source of the oocysts was the Braemar STP. This was evidenced by the following facts: • The volume of discharge from the STP outlet is the primary source of flow into Gibbergunyah Creek during low flow periods (when most of the elevated Cryptosporidium levels were recorded). There was a clear conductivity increase at monitoring site E203 with the observed conductivity lower upstream of the STP discharge than downstream. The conductivity of the STP discharge was approximately 0.7 mS/cm compared to an upstream concentration approximately 0.3 mS/cm and a downstream conductivity (at E203) of between 0.5–0.7 mS/cm. • On two of the three sampling days in the study, the only detections of Cryptosporidium were from the STP outlet and the sites downstream of the STP. On one sampling day Cryptosporidium was detected at a site upstream of the STP (but downstream of a mushroom factory). The UNSW study measured the Cryptosporidium concentrations in both the raw sewage and treated effluent at the Braemar STP. The average concentration of Cryptosporidium was reduced from 16 oocysts/L in the raw sewage to 1.1 oocysts/L in the discharged effluent. The outlet concentration was in line with that of other STPs investigated in the study.

Are the Cryptosporidium oocysts observed at E203 viable? Detection methods for Cryptosporidium oocysts are a presence/absence count and give no information about viability. If the UV treatment process in the Braemar STP is working effectively (i.e. inactivating but not removing oocysts), the oocysts detected should not be viable. The disinfection capability of the Braemar STP is partially demonstrated by the fact that the concentration of E. coli coming out of the STP outlet is extremely low. In fact the SCA study found that samples taken upstream of the STP discharge had higher E. coli concentrations than those taken at E203. This suggests that the STP effluent is diluting the E. coli levels. As the STP does not undertake chlorine disinfection, it must be assumed that the UV treatment is at least effective in killing bacteria pathogens. The UNSW researchers noted that oocysts inactivated by UV irradiation are likely to have intact DNA that will stain the same as live oocysts which is why it is difficult to differentiate between live and dead oocysts. The researchers found that only four out of the eleven treated effluent samples taken at Braemar STP had sufficiently high total oocyst numbers to allow viability testing. These tests (on 282 oocysts) found no viable oocysts and therefore suggested that the oocysts detected at E203 were intact, but not viable. Their report specifically states: Protozoans from the STPs are likely to be frequently detected in Gibbergunyah Creek. But they are likely to also be non-viable to a degree that the normal ‘confirmed’ count would be uninformative and an unsound management trigger. Cryptosporidium has not been detected at the downstream monitoring site E206 (5 km downstream of E203), and this also supports the conclusion that the Cryptosporidium detections at E203 are non-viable oocysts from the Braemar STP.

Further investigations The above findings suggest that Braemar STP is not atypical of most STPs in the SCA catchments which employ UV treatment processes. If this is the case then

Chapter 6 – Water Quality 139 Cryptosporidium oocysts are likely to be detected in the receiving waters immediately below other STP discharges. More importantly, any oocysts detected should not be viable and should not be detectable further downstream due to their subsequent disintegration and/or deposition enroute. The SCA therefore proposes to obtain samples from the raw effluent and treated effluent of another three or four STPs as well as from locations some 5 kilometres below each discharge point. This will: • provide confirmation of the findings in relation to the Gibbigunyah detections • identify any differences in the effectiveness of the UV treatment processes at the different STPs • ascertain the effect of stream distance and character on the downstream fate of the oocysts. Source: SCA 2010a

Implications The UNSW report was not made available to the Auditor, however, the Auditor accepts the significant work that has been undertaken on the sources and potential viability of Cryptosporidium and Giardia in Gibbergunyah Creek. The Auditor also accepts there is a high likelihood that most if not all Cryptosporidium and Giardia at site E203 are not viable. Nevertheless, given the persistent, and in some cases relatively high levels of detections (see Figure 6.1.1), in Gibbergunyah Creek the Auditor believes that one final check should be made on the viability of Cryptosporidium and Giardia oocysts/cysts directly from site E203. Cell culture viability testing of Cryptosporidium and Giardia in water samples from Gibbergunyah Creek at site E203 are recommended for this purpose.

Figure 6.1.1: Cryptosporidium and Giardia in water samples from Gibbergunyah Creek at site E203

140 2010 Audit of the Sydney Drinking Water Catchment

Figure 6.1.2: Cryptosporidium and Giardia in water samples from Werriberri Creek at site E531

As far as the Auditor can tell, persistent detections of Cryptosporidium and Giardia in Werriberri Creek (see Figure 6.1.2) and at Prospect WFP still warrant further investigation. Understanding the sources, viability and infectivity of pathogens at these sites should be a component of an ongoing adaptive management approach to managing the risk of pathogens in the Catchment.

Recommendation 19: The SCA continue to investigate the cause of persistent detections of Cryptosporidium and Giardia oocysts/cysts in the Catchment.

6.2 Nutrient load

Background Small amounts of nutrients are required for plant growth. However, in large amounts, nutrients can cause excessive algal growth and other plants (including aquatic weeds) in waterways. Excessive algal growth can disturb natural ecosystem processes and affect the health of waterways (DEC 2003) Nutrient loads result from a complex relationship between catchment and input sources, including natural inputs from inherent geological features and soil types, diffuse sources such as runoff from agricultural and urban areas, and point sources such as STPs. The main human-induced sources of nutrients in rivers include runoff from urban areas, erosion and runoff from grazing and cultivated land, tail water from irrigation areas, river and stream bank erosion and point source discharges (DEC 2005). Point sources of nutrients include STP discharges and other industrial discharges. Nutrient point sources have potential to cause severe long-term impacts on water quality and ecosystem health because they are commonly continuous sources of nutrients, rather than intermittent inputs during rainfall events. Rivers that receive

Chapter 6 – Water Quality 141 large volumes of STP effluent may be prone to eutrophication and algal blooms. (DECC 2007a) As identified in past audits, the magnitude and management of nutrient load cannot be determined unless the relative contribution of all sources of nutrient pollution is understood. Hence, while the recommended measure for this indicator is limited to tallies of non-compliances of nutrient point sources within the Catchment area (NOW, 2009), the present audit still includes an assessment of all nutrient sources where data are available. Specifically, the present audit has examined: • estimates of diffuse total nitrogen (TN) and total phosphorus (TP) loads from each sub-catchment • estimates of diffuse TN and TP loads from major land use types within a sub- catchment • estimates of nutrient loads from STPs with Environmental Protection Licences • level of compliance of sites of point source input with Environmental Protection Licences. It should be noted that the nutrient load estimates do not include contributions from soil erosion, stormwater and villages that are served by on-site effluent management systems such as septic tanks. Local estimates for these sources are difficult to obtain for all areas of the Catchment area but are likely to be significant (Armstrong and Mackenzie 2002; DECC 2009a). Also, of likely significance, are the nutrient loads arising from licensed premises other than STPs (e.g. power generation plants). The lack of data in this case reflects the current Environmental Protection Licences, which have no requirement to report nutrient load discharges from such premises.

Findings – diffuse nutrient loads The same estimates of diffuse nutrient loads, and subsequently, the same management priorities have been recommended in the last 3 audits (DEC 2003, 2005; DECC 2007a). The present audit provides outcomes of recent diffuse nutrient load modelling conducted by DECCW. The models were developed for all coastal catchments in NSW, including those in the Catchment area (Dela-Cruz and Scanes 2009; Littleboy et al. 2009). The models were calibrated using best available data, such as those arising from monitoring in the Lake Burragorang and Nepean Catchments (AWT 2003). The model outcomes provide long term steady state estimates of annual nutrient loads, and have been used to inform report cards for the NSW Natural Resource Management MER strategy and for the State of the Catchments 2010 report (www.environment.nsw.gov.au/soc/NaturalresourcesMER.htm). Over 50% of diffuse TN and TP loads arise from agricultural activities, which cover around 37% of the total area of the Catchment (Figures 6.2.1 and 6.2.2). The remainder of the load predominantly arises from areas of conservation and scrub, which cover around 50% of the total area of the Catchment. On an aerial basis (i.e. per km2), both TN and TP loads from conservation and shrubland areas in the Catchment are significantly lower than other land use types (Table 6.2.1). These findings are consistent with those presented for forested catchments in other parts of Australia, where it has also been shown that much of the nutrient load is delivered in the form of organics and particulates (Harris 2001) that are not as readily available for use by cyanobacteria and phytoplankton. Table 6.2.1 (a and b) summarises the range of diffuse TN and TP loads arising from various land use types in the Catchment area. The land use types/categories reflect those used for the DECCW diffuse nutrient load modelling. The wide range in loads

142 2010 Audit of the Sydney Drinking Water Catchment

Figure 6.2.1: Long-term steady state estimate of diffuse TN loads (kg/y) in the Catchment

Note: Grey areas within the Catchment reflect no data provided in original diffuse load modelling by DECCW (Dela-Cruz and Scanes 2009; Littleboy et al. 2009). Data gaps arise from gaps in land-use map at the time of modelling. For this audit, data gaps were filled using the land-use map provided by SCA.

Figure 6.2.2: Long term steady state estimate of diffuse TP loads (kg/y) in the Catchment

Note: Grey areas within the Catchment reflect no data provided in original diffuse load modelling by DECCW (Dela-Cruz and Scanes 2009; Littleboy et al. 2009). Data gaps arise from gaps in land-use map at the time of modelling. For this audit, data gaps were filled using the land-use map provided by SCA. (expressed as a generation/export rate kg/km2/y) arises from spatial variability in climate, soil types and topography within the Sydney Drinking Water Catchment area. This is best illustrated by comparing the diffuse TN and TP loads from the Back Creek/Round Mountain Creek, Mulwaree River and Wollondilly River sub- catchments, which have extensive areas of grazing land. There is large spatial variability in TN and TP exports from grazing within the Back Creek/Round Mountain sub-catchment. Significantly greater loads arise from grazing areas underpinned by earthy soils compared to those underpinned by red earths. Even greater spatial variability in TN and TP exports from grazing are observed when comparing sub- catchments. Exports from grazing areas in the Mulwaree River and the Wollondilly River sub-catchments are up to 645 times lower than in those of the Back Creek/Round Mountain Creek sub-catchment. In addition to varying soil types, different climate regimes are also likely to account for the spatial variability in TN and TP loads from grazing land in these sub-catchments. Figure 6.2.3 provides a relative ranking of sub-catchments based on total annual diffuse TN and TP loads. The highest diffuse TN loads arise from the Back Creek/Round Mountain sub-catchment, followed by the Braidwood Creek, Kangaroo River, Wollondilly River and Mongarlowe River sub-catchments. Collectively these 5 sub-catchments contribute ~50% of the total annual diffuse TN loads from the Catchment area. The highest diffuse TP loads arise from the Wollondilly River, Braidwood Creek, Kangaroo River, Back Creek/Round Mountain Creek, and Wingecarribee River sub-catchments. These sub-catchments collectively contribute ~46% of the total annual diffuse TP loads from the Catchment area. Overall, the ranking of sub-catchments differs from that of previous audits – for example, in previous audits diffuse TN loads from the Back Creek/Round Mountain Creek sub- catchment were found to be relatively moderate in comparison to TN loads from the Wollondilly sub-catchment (DEC 2003, 2005; DECC 2007a). One likely reason for the difference in rankings arises from the input data used for the modelling. Since the 2007 audit, significant efforts have been made to develop a state-wide land use map using ALUM classification (http://adl.brs.gov.au/mapserv/landuse/index.cfm?fa=app.ALUMClassification). As a consequence, a greater number of land use classes were used for the recent DECCW diffuse nutrient load model than used in the original model for the 2003, 2005 and 2007 audits. The recent modelling breaks the agriculture class (used in the original model) into 5 classes resulting in a large number of TN and TP export rates that reflect not only land use but also the varying soil types, topography and climate regime in the Catchment area. This is in contrast to the single TN export and TP export rate applied to all agricultural land in the original model.

Chapter 6 – Water Quality 143 Table 6.2.1a: Total nitrogen load and average export rate from dominant land uses in the Catchment

Area Total Rate Rate Rate Rate Land use (km2) (kg/y) (kg/km2/y) stdev min max Cleared land 57.11 70268 1346.1 1085.2 138.7 6018.1 Conservation and scrub 8389.83 947410 180.6 926.3 0.0 14319.9 Cropping 8.52 2326 247.8 161.4 0.0 828.1 Intensive cultivation 27.08 121338 4633.7 3350.3 0.0 16093.6 Tree horticulture 1.4 4592 3696.2 3506.6 46.8 12393.2 Grazing 5865.42 1343455 308.2 1062.5 0.0 16125.5 Irrigated pasture 5.26 9242 1794.3 1271.6 242.4 5716.2 Urban 325.25 219502 717.6 1813.4 18.7 13975.4

Table 6.2.1b: Total phosphorus load and average export rate from dominant land uses in the Catchment

Area Total Rate Rate Rate Rate Land use (km2) (kg/y) (kg/km2/y) stdev min max Cleared land 57.11 7075 144.6 150.1 12.5 1173.2 Conservation and scrub 8389.83 55807 10.5 52.5 0.0 812.5 Cropping 8.52 311 33.2 21.6 0.0 110.9 Intensive cultivation 27.08 6885 262.9 190.1 0.0 913.1 Tree horticulture 1.4 262 210.6 198.1 6.2 703.2 Grazing 5865.42 125367 26.8 60.9 0.0 915.0 Irrigated pasture 5.26 3636 722.5 572.6 41.1 2461.5 Urban 325.25 21493 69.9 103.4 3.5 793.0

144 2010 Audit of the Sydney Drinking Water Catchment

a) diffuse TN load (kg/y) 0 50000 100000 150000 200000 250000 300000 350000 400000

Back Creek & Round Mountain Creek Braidwood Creek Kangaroo River Wollondilly River Mongarlowe River Wingecarribee River Upper Nepean River Mid Shoalhaven River Reedy Creek Jerrabattgula Creek Mid Coxs River Mulwaree River Nerrimunga Creek Bungonia Creek Boro Creek Upper Wollondilly Upper Coxs River Lake Burragorang Kowmung River Lower Coxs River Nattai River Endrick River Upper Shoalhaven River Werriberri Creek Woodford Creek Little River Woronora River Lake Greaves Cascade Creek

b) diffuse TP load (kg/y) 0 5000 10000 15000 20000 25000 30000

Wollondilly River Braidwood Creek Kangaroo River Back Creek & Wingecarribee River Mongarlowe River Reedy Creek Upper Nepean River Jerrabattgula Creek Mulwaree River Nerrimunga Creek Mid Shoalhaven Mid Coxs River Boro Creek Upper Wollondilly Bungonia Creek Upper Coxs River Kowmung River Lower Coxs River Lake Burragorang Nattai River Upper Shoalhaven Endrick River Werriberri Creek Woronora River Little River Woodford Creek Lake Greaves Cascade Creek

Figure 6.2.3: Relative ranking of sub-catchments within the Catchment based on total annual diffuse TN (kg/y) and TP (kg/y) loads

Chapter 6 – Water Quality 145 Findings – point source nutrient load DECCW licenses discharges from STPs under the (POEO Act). There are currently 11 licensed STPs that discharge treated effluent within the Catchment area and four STSs that discharge treated effluent outside the Catchment area but whose sewerage reticulation systems can potentially overflow within the area. The STPs discharging within the Catchment are located at Berrima, Bowral, Braemar (Mittagong), Braidwood, Bundanoon, Goulburn, Jenolan Caves, Lithgow, Moss Vale, Marulan and Wallerawang. With the exception of the Goulburn and Marulan STPs where the effluent is discharged to land in effluent irrigation systems, all of the Catchment’s STPs discharge directly into the waterways of the Catchment. The STSs discharging outside the Catchment but whose overflows can potentially impact upon the Catchment are Blackheath, The Oaks / Oakdale (part of West Camden STS), Warragamba (now referred to as the Wallacia STS) and Winmalee. The council operators of the Bowral, Braemar (Mittagong), Lithgow, Moss Vale, Bundanoon and Goulburn STSs are required to collect data on phosphorus and nitrogen loads from the STPs as part of the load-based licensing scheme under the POEO Act. This data has been used to compare phosphorus and nitrogen loads discharged from STPs in the Catchment (Figures 6.2.4 and 6.2.5 and Tables 6.2.2 and 6.2.3). There are also eight small package STPs in the Catchment that are not licensed by DECCW but are regulated by councils. There was no information provided to indicate the effectiveness of the environmental management of these plants.

Load of Phosphorus (kg / year) discharged from Sewage Treatment Plants over the last 10 years

Moss Vale (Kg)

Mittagong (Kg)

Lithgow (Kg)

Goulburn (Kg)

Bundanoon (Kg)

Bowral (Kg)

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 Kg (P) / year

2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10

Figure 6.2.4: Loads of TP discharged from STPs in the Catchment between August 2000 and June 2010

146 2010 Audit of the Sydney Drinking Water Catchment Table 6.2.2: Load of TP (kg) discharged from STPs in the Catchment between August 2000 and June 2010

From To Bowral Bundanoon Goulburn Lithgow Mittagong Moss Vale 1-Aug-00 31-Jul-01 983 94 19926 8721 3650 81 1-Aug-01 31-Jul-02 1089 121 14642 8064 0* 347 1-Aug-02 31-Jul-03 848 142 10744 9895 97 229 1-Aug-03 31-Jul-04 1478 137 12223 9058 219 273 1-Aug-04 31-Jul-05 1181 86 8256 9371 115 95 1-Aug-05 31-Jul-06 1191 69 7540 6577 165 158 1-Aug-06 31-Jul-07 632 68 3883 2267 167 120 1-Aug-07 31-Jul-08 270 112 5593 924 236 263 1-Aug-08 31-Jul-09 216 81 8374 5202 139 86 1-Aug-09 30-Jun-10 207 77 8800 3950 135 87 * denotes changeover from Mittagong to Braemar STP

Load of Nitrogen (kg / year) discharged from Sewage Treatment Plants over the last 10 years

Moss Vale (Kg)

Mittagong (Kg)

Lithgow (Kg)

Goulburn (Kg)

Bundanoon (Kg)

Bowral (Kg)

0 10000 20000 30000 40000 50000 60000 70000 80000 90000 Kg (N) / year

2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10 Figure 6.2.5 Loads of TN discharged from STPs in the Catchment between August 2000 and June 2010 The TP load discharged by STPs in the Catchment area has steadily decreased from 69.6 tonnes in the 2001–2004 period to 41.9 tonnes in the 2004–2007 period to 34.8 tonnes in the current audit period (2007–2010). No such decline is observed for the TN load discharged by STPs in the Catchment area. TN loads have remained relatively stable for the corresponding periods with values of 253.8 tonnes (2001– 2004), 233.0 tonnes (2004–2007) and 253.1 tonnes (2007–2010). Based on the latest annual estimates, STPs in the Wollondilly and Upper Coxs sub-catchments discharge the greatest TN and TP loads.

Chapter 6 – Water Quality 147 Table 6.2.3 Loads of TN discharged from STPs in the Catchment between August 2000 and June 2010

Moss Bowral Bundanoon Goulburn Lithgow Vale (Winge- (Wollon- (Wollon- (Upper Mittagong (Winge- From To carribee) dilly) dilly) Coxs) (Nattai) carribee) 1-Aug-00 31-Jul-01 17602 960 76535 18916 13939 1873 1-Aug-01 31-Jul-02 17622 1162 35115 18091 0* 4917 1-Aug-02 31-Jul-03 21930 937 45272 17226 4760 3822 1-Aug-03 31-Jul-04 25065 1334 29743 15671 6721 4364 1-Aug-04 31-Jul-05 28267 947 22418 17582 5010 1598 1-Aug-05 31-Jul-06 22601 767 26801 20469 6545 4692 1-Aug-06 31-Jul-07 9391 1086 31817 19905 6158 6959 1-Aug-07 31-Jul-08 9729 1890 31159 15772 6744 8121 1-Aug-08 31-Jul-09 6821 1808 58634 18920 5449 5763 1-Aug-09 30-Jun-10 7462 1443 44145 15900 6352 7028

* denotes changeover from Mittagong to Braemar STP

Temporal changes in the TN and TP loads from STPs were due to upgrades, decommissioning and/or establishment of new STPs. Specifically: • Mittagong STP was decommissioned in 2001 and replaced by a new STP at nearby Braemar, although the discharge point (in Iron Mines Creek) remained unchanged. This has resulted in a decline in TP and TN loads from 2001 to 2003 (Figures 6.2.4 and 6.2.5) • Bowral STP was commissioned in the 2007 audit period. This has resulted in an associated decline in TP and TN loads (Figures 6.2.4 and 6.2.5). • Mount Victoria and Blackheath STPs were decommissioned in 2007–08 and 2008–09 respectively, with effluent being transferred to the Winmalee STS. This means Sydney Water will no longer discharge treated wastewater into the Coxs and Grose rivers or in the World Heritage listed Blue Mountains National Park. • upgrades of existing STPs and associated sewage transfer and utilisation works was undertaken at Bowral, Braidwood, Bundanoon, Lithgow, Wallerawang and Goulburn – a marked decline in TP and TN (Figures 6.2.4 and 6.2.5) is noted for Lithgow in 2007 (the 924 kg in the 2007–2008 year is noted and probably should be averaged with the exceedingly high 5202 kg for the following year) • current work in association with councils to build new STPs that collect and treat sewage, and safely transfer and use treated sewage at Robertson, Taralga and Kangaroo Valley. The STS Environment Protection Licences covering the STPs in the Catchment area also impose effluent concentration and load limits, and effluent and system monitoring requirements. Table 6.2.4 summarises the load limit and monitoring non- compliances of STPs in the Catchment area during the current audit14.

14 Not all of the 2009–2010 data was available for the audit.

148 2010 Audit of the Sydney Drinking Water Catchment Table 6.2.4: Limit and monitoring non-compliances summary of STPs in the Catchment during the 2007–2010 audit

Licence Oil & Faecal Sludge Volume STP number Year PH BOD TP TN Aluminium TSS grease coliforms Monitoring storage limit Berrima 3575 2006–07 X (Wingecarribee) 2007–08 4X 6X 2008–09 4X 2009–10* X X Bowral 1749 2006–07 X X X X (Wingecarribee) 2007–08 26X 15X 2008–09 X 2009–10* Braemar / 10362 2006–07 X 2X 5X Mittagong 2007–08 2X (Nattai) 2008–09 X 2009–10* Braidwood 1733 2006–07 2X 3X 26X (Braidwood) 2007–08 1X 7X 19X 2008–09 4X 6X 6X 2009–10* X X Bundanoon 2006–07

(Wollondilly) 2436 (ND) 2007–08 3X 2X 12X 2008–09 X 2009–10* X X Goulburn 1742 2006–07 X 5X 23X (Wollondilly) 2007–08 X 5X 7X 2008–09 2X 5X 2X 2009-10* X 2X 3X X

Chapter 6 – Water Quality 149 Table 6.2.4 (continued) Limit and monitoring non-compliances summary of STPs in the Catchment during the 2007–2010 audit

Licence Oil & Faecal Sludge Volume STP number Year PH BOD TP TN Aluminium TSS grease coliforms Monitoring storage limit Jenolan Caves 1962 2006-07 (Mid Coxs) 2007-08 12X 13X 2X 2008-09 X 2X 2009-10* 6X 6X Lithgow 236 2006-07 14X 14X 14X 14X 14X 12X (Upper Coxs) 2007-08 2X X X X 2008-09 X 10X X 3X 2009-10* 4X Moss Vale 1731 2006-07 X (Wingecarribee) 2007-08 X 10X 2008-09 X 2009-10* X Wallerawang 598 2006-07 2X 5X X X 186X (Upper Coxs) 2007-08 3X X 3X 12X 157X 2008-09 X 2009-10* X X Source: DECCW data 2010 Note: * non-compliance data incomplete for 2009–2010 Jenolan STP was upgraded in January 2010 and there have been no non-compliances over the period since upgrade – January to June 2010. An upgrade to Wallerawang STP has now commenced with a completion date of June 2012. Upgrades to Lithgow STP should be complete by late December 2010–January 2011. New discharges limits have been incorporated into the Lithgow EPL.

150 2010 Audit of the Sydney Drinking Water Catchment Findings – combined diffuse and point source nutrient loads Table 6.2.5 summarises the combined contributions of point and diffuse TN and TP loads for each sub-catchment in the Catchment area. Of significance are the loads from the following 6 sub-catchments, which contribute over 50% of the total TN and TP loads in the Catchment area: Wollondilly River, Braidwood Creek, Kangaroo River, Back Creek/Round Mountain Creek, Wingecarribee River and Mongarlowe River. These sub-catchments, with the exception of the Mongarlowe River sub- catchment, have been identified as having high risk to nutrient (TN and TP) pollution by the SCA’s CDSS. The CDSS may be considered as an independent approach for assessing the state of nutrient load in the Catchment as it relies on quantitative and qualitative weightings to assign the rate of risk to nutrient pollution rather than the traditional quantitative modelling approach. The CDSS examines a greater number of contributing sources than the DECCW diffuse nutrient load modelling, and as a consequence, has identified a greater number of sub-catchments that are at risk of nutrient pollution (e.g. Lower Coxs River, Upper Wollondilly River and Mulwaree River). As indicated above, differences in the outcomes of the DECCW diffuse nutrient load modelling and the CDSS assessments do exist (e.g. Mongarlowe River). Discrepancies are most likely partly due to the different approaches and partly to inadequate and/or uncertain input data. The significance of the latter case is shown in a recent study that assessed sources of sediment and nutrient pollution in sub-catchments that drain to Lake Burragorang (Rustomji 2006). The study found that relatively large loads arise from forested sub-catchments around Lake Burragorang, on the assumption that 40 tonnes/km2/y of sediment (and associated nutrient bound sediments) is exported from such areas. This generation/export rate is almost 300 times greater than the rate used in the DECCW diffuse nutrient load modelling, which was developed using local nutrient concentration measurements in the Catchment (Dela-Cruz and Scanes 2009; see also AWT 2003). Future work is required to resolve these discrepancies.

Implications As discussed elsewhere in the report, nutrient enrichment has a direct impact on raw water quality and may result in stimulation of growth of cyanobacteria and nuisance algae. Management of nutrient loads to the river systems in the Catchment area is of obvious priority. Other sections of the audit report describe the numerous remediation works and education programs being implemented by various agencies and authorities to help reduce diffuse TN and TP loads from intensive land use practices in the Catchment area. In addition to these, the SCA’s (2010b) Healthy Catchments Strategy 2009– 2012 outlines priorities for preventative and remediation works. Recent activities (2008–09) include the: • Riparian Management Assistance Program, which helps private landowners protect, improve and manage waterway frontages via stock fencing, alternative water supplies and shade for stock, native plantings, and minor erosion control • Sustainable Grazing Program (done in collaboration with the Department of Industry and Investment) helps graziers increase the sustainability of their enterprises and protect the quality of water flowing from paddocks to waterways in the Mid Coxs, Upper Werriberri, Upper Nepean, Kangaroo Valley, Upper Wingecarribee, and in the areas around Eastern Wollondilly • Catchment Protection Scheme, which is a joint initiative between landowners, the SCA, and HNCMA and SRCMA – the two priorities of the scheme are to protect stream beds and banks, and riparian vegetation. Since 1960, the scheme has

Chapter 6 – Water Quality 151 effectively treated severely eroded landscapes to reduce the amount of sediment and nutrients washed into the catchments and water storages, protected vulnerable soil, and improved farm management • Dairy Waste Program, which helps reduce the risk to water quality from pathogens and nutrients in high concentrations in animal manure – the program has allowed feed pads (holding areas for cows prior to milking) to be upgraded, development and dissemination of a dairy self assessment tool (known as DairySAT) to identify key environmental risks on properties including those related to effluent management, soil nutrients, chemicals and other farm waste The Healthy Catchments Strategy 2009–2012 also outlines programs for improving sewage management. There are three main programs: • The Accelerated Sewerage Program – the SCA’s largest investment and operates in conjunction with the Country Towns Water Supply and Sewerage Program administered by NOW. The program funds projects to upgrade existing systems for treating, transporting and irrigating sewage, as well as new sewerage systems for previously non-sewered residential areas. As indicated earlier, the achievements of this program are clearly shown by reductions in nutrient loads from various STPs. An estimated 11.9 tonnes of nitrogen and 8.5 tonnes of phosphorus will be prevented from entering the river systems. • The On-site Sewage Program – there are an estimated 16,000 on-site sewage systems in the catchments. The SCA provides on-site sewage management grants to assist councils with their responsibility for inspecting, upgrading and servicing the systems. Of the systems inspected between 2008 and 2009, 13.6% were considered to have a potential effect on water quality. Sixty percent of these were fixed within the year and councils continue to work with property owners to improve non-compliant systems • The Sewage Reticulation Program – grants were provided for performance assessments of council sewage reticulation systems at Goulburn, Moss Vale, Berrima, Bundanoon, Mittagong, Bowral, Lithgow and Wallerawang.

Future directions The number of on-going non-compliances for STPs, and the potential large loads from diffuse sources of nutrient pollution implies a continued need for preventative and remediation works. Hence, as recommended in past audits, the Auditor recommends that operators and regulators of STPs continue efforts to reduce current nutrient discharges. Given that annual TN and TP load contributions from diffuse sources are significantly greater than those from STPs, the Auditor also recommends that regulators continue efforts to assist landholders with implementing land use practices which minimise or prevent nutrients (and other pollutants) entering the river systems. In addition, the Auditor recommends that nutrient contributions from diffuse sources be continued to be assessed in future audits. For this to take place however, better accounting of the loads is required to help resolve the discrepancies described above. This is best met through local measurements of nutrient exports. The SCA currently undertakes monitoring of flows and nutrient concentrations in some sub- catchments. It is recommended that this monitoring network be expanded so that there is at least one monitoring station in each sub-catchment. The feasibility of estimating nutrient exports from soil erosion, stormwater, villages that are served by on-site effluent management systems and licensed point source premises other than STPs should also be investigated.

152 2010 Audit of the Sydney Drinking Water Catchment Recommendation 20: The operators and regulators of sewage treatment systems in the Catchment should continue efforts to reduce nutrient loads.

Recommendation 21: Estimates of nutrient loads from diffuse sources should be included in future audits in order to understand the full context of nutrient loading in the Catchment.

Table 6.2.5: Combined contributions of point and diffuse TN (tonnes/year) and TP (tonnes/year) loads for each sub-catchment within the Catchment Sub-catchment TN (tonnes/year) TP (tonnes/year) Back Creek & Round 337.73 20.84 Mountain Creek Boro Creek 57.92 6.17 Braidwood Creek 329.05 21.98 Bungonia Creek 60.25 5.24 Cascade Creek 0.37 0.04 Endrick River 24.91 1.71 Jerrabattgulla Creek 121.96 10.21 Kangaroo River 248.83 21.26 Kowmung River 38.53 3.18 Lake Burragorang 39.04 2.61 Lake Greaves 0.55 0.06 Little River 8.81 0.70 Lower Coxs River 29.55 2.68 Mid Coxs River 91.84 8.17 Mid Shoalhaven River 141.64 8.85 Mongarlowe River 234.47 15.24 Mulwaree River 82.30 9.75 Nattai River 32.04 (6.4*) 2.36 (0.14*) Nerrimunga River 71.49 9.29 Reedy Creek 129.15 10.63 Upper Coxs River 56.87 (15.9*) 8.31 (3.95*) Upper Nepean River 104.92 8.30 Upper Shoalhaven River 21.70 2.04 Upper Wollondilly 49.14 6.01 Werriberri Creek 19.04 1.57 Wingecarribee River 219.25 (14.5*) 16.94 (0.29*) Wollondilly River 290.69 (45.6*) 34.24 (8.9*) Woodford Creek 10.31 0.69 Woronora River 7.49 0.89

Notes: Diffuse source loads arise from models developed by Dela-Cruz and Scanes (2009) and Littleboy et al (2009) and point source loads were obtained from DECCW. * Contribution from point sources, for example, for Nattai River, the total TN load is 32.04 tonnes/y, of which 6.4 tonnes arises from point sources.

Chapter 6 – Water Quality 153 6.3 Cyanobacterial blooms

Background Cyanobacteria, also known as blue–green algae, are bacterial photosynthetic autotrophs commonly found in freshwater systems. Growth and subsequent blooms of cyanobacteria are stimulated under a specific combination of environmental conditions – these include high nutrient concentrations, reduced river flows, high light penetration and warm water temperatures. Waters that flow slowly with low turbulence, such as regulated rivers, dams or water storages, are considered to be at a particularly high risk of blooms. Concentrations of nutrients in the water determine the magnitude of the blooms, with high nutrient concentrations culminating in large blooms. Cyanobacteria blooms are of particular concern because some species produce toxins that have harmful effects on tissues, cells and organisms (NHMRC 2008). If the toxicity of the bloom is significant, the water becomes unusable for drinking and direct contact. At low concentrations, toxic cyanobacteria are of less concern but some may still cause strong tastes and odours in treated water. Two types of guidelines are used nationally to manage the public health risks of toxicity from cyanobacteria: • the National Health and Medical Research Council’s Guidelines for Managing Risks in Recreational Water (NHMRC 2008) • the National Health and Medical Research Council’s Australian Drinking Water Guidelines (NHMRC and NRMMC 2004).

Guidelines for managing risks in recreational water The National Health and Medical Research Council’s Guidelines for Managing Risks in Recreational Water (NHMRC 2008) states that fresh recreational water bodies should not contain: • ≥10 µg/L total microcystins; or > 50 000 cells/mL toxic Microcystis aeruginosa; or biovolume equivalent of > 4 mm3/L for the combined total of all cyanobacteria where a known toxin producer is dominant in the total biovolume, or • ≥ 10 mm3/L for total biovolume of all cyanobacterial material where known toxins are not present, or • cyanobacterial scums consistently present. The recommended method for interpreting and applying the guideline is via a risk- based approach, which describes three alert levels for management response: • Green alert: ≥ 500 < 5000 cells/mL M. aeruginosa or biovolume equivalent of ≥ 0.04 < 0.4 mm3/L for combined total of all cyanobacteria • Amber alert: ≥ 5000 < 50000 cells/mL M. aeruginosa or biovolume equivalent of ≥ 0.4 < 4 mm3/L toxic cyanobacteria, or biovolume equivalent ≥0.4 to < 10 mm3/L all cyanobacteria where known toxins are not present • Red alert: ≥ 10 µg/L total microcystins, or ≥ 50000 cells/mL M. aeruginosa or biovolume equivalent of ≥ 4 mm3/L toxic cyanobacteria, or biovolume equivalent > 10 mm3/L all cyanobacteria where known toxins are not present Green alerts indicate that regulators should continue their routine sampling for cyanobacteria. Amber alerts indicate that investigations into the causes of the elevated levels of cyanobacteria, as well as increased sampling, be undertaken to enable more accurate assessments of the risks to recreational users. Red alerts indicate that local authorities should issue warnings that the water body is unsuitable for primary contact.

154 2010 Audit of the Sydney Drinking Water Catchment Australian Drinking Water Guidelines The National Health and Medical Research Council’s Australian Drinking Water Guidelines (NHMRC and NRMMC 2004) provide the following guidelines for water storages: • 500 cells/mL toxic cyanobacteria – increase monitoring • 2000 cells/mL toxic cyanobacteria – consider need for toxicity testing (seek expert advice) • 6500 cells/mL toxic cyanobacteria – seek advice from health authority.

Regional Algal Coordinating Committees Within NSW, a number of Regional Algal Coordinating Committees are responsible for developing, coordinating and implementing algal bloom contingency strategies. Incidences of algal blooms in the Catchment area are reported to the Metropolitan and South Coast Regional Algal Coordinating Committee (M-SC RACC). The M-SC RACC applies the three alert levels outlined in the recreational guidelines in response to reported cyanobacterial blooms. As an additional precautionary step, the M-SC RACC recommends that for potable water supplies, water supply managers should seek advice from the health authority when cell counts exceed 2000 cells/mL and/or enact their algal risk management plan and/or refer to the Water Directorate Blue–Green Algal Management Protocols.

Audit approach Two types of data were used in the present audit to provide an assessment of the state of cyanobacterial blooms in the Catchment: 1. incidence of green, amber and red alerts provided to the M-SC RACC since the last audit, note that incidence is given by the number of weeks under alert 2. cyanobacterial cell counts, biovolumes and microcystin concentrations in water samples collected as part of SCA’s water quality monitoring program (www.sca.nsw.gov.au/water-quality/monitoring-and-testing). The SCA routinely monitors cyanobacteria in major storages and in river systems that have a history of algal activity. Monitoring is usually conducted monthly, but between October and May each year, when environmental conditions for cyanobacteria growth are known to be favourable, monitoring frequency is increased to weekly. Monitoring frequency is increased in response to thresholds specified in the SCA’s Cyanobacteria Response Plan, which is consistent with the recreational and drinking water guidelines described above. Consistent with the SCA’s application of the guidelines (SCA 2009e), this audit has applied the guidelines in accordance with the end use of the water. Hence, the recreational guidelines have been applied to all river (monitoring) sites and to the lake/reservoir sites used by the general public (i.e. Lake Yarrunga, Fitzroy Falls and downstream of the Wingecarribee Reservoir). The drinking water guidelines have been applied to all other lake/reservoir (monitoring) sites.

Chapter 6 – Water Quality 155 Findings – incidence of blooms According to the data provided by the M-SC RACC, the number of weeks of alerts raised in the Catchment between 2007 and 2008 was 36. Almost half (15) of the blooms occurred downstream of the Lithgow STP in Farmers Creek (Figure 6.3.1a). The blooms were of sufficient size to warrant red alerts. A relatively large number of amber and green alerts were issued for the Wingecarribee River at Sheepwash Bridge, which is surrounded by grazing land. A relatively small number of green and amber alerts were issued for Lake Yarrunga at the Bendeela Picnic Area.

a) 2007-2008 35

30

25

20 Green Amber 15 Red

10 Number of alert weeks Number under 5

0 Farmers Creek, Wingecarribee Lake Yarrunga Fitzroy Falls Lake Lyell Pejar Reservoir downstream River, (Bendeela Picnic Reservoir Lithgow STP Sheepwash Area) Bridge

b) 2008-2009 35

30

25

20 Green Amber 15 Red

10 Number of alert weeksNumber under 5

0 Farmers Creek, Wingecarribee Lake Yarrunga Fitzroy Falls Lake Lyell Pejar Reservoir downstream River, (Bendeela Picnic Reservoir Lithgow STP Sheepwash Area) Bridge

Figure 6.3.1: Cyanobacterial bloom alerts in the Catchment Source: Metropolitan and South Coast Regional Algal Coordinating Committee Note: Colour coding corresponds with the green, amber and red alert levels specified for cyanobacteria in the NHMRC (2008) recreational guidelines.

156 2010 Audit of the Sydney Drinking Water Catchment The total number of weeks of alerts raised between 2008 and 2009 was over 3 times greater (117) than in the previous year. A large proportion of alerts issued were green, with the majority occurring in the Wingecarribee River at Sheepwash Bridge and the Fitzroy Falls Reservoir (Figure 6.3.1b). Red alerts were again issued downstream of the Lithgow STP in Farmers Creek, and additionally in the Pejar Reservoir which is also surrounded by grazing land. A small number of green or amber alerts were issued for Lake Lyell and the Bendeela Picnic Area at Lake Yarrunga.

Findings – Compliance with Recreational (NHMRC 2008) and Australian Drinking Water Guidelines (NHMRC & NRMMC 2004) Table 6.3.1 summarises the median and maximum biovolume equivalents of total and potentially toxic cyanobacteria, and the Microcystin LR equivalent in samples collected from river monitoring sites and lake/reservoir monitoring sites used by the general public. Note that the data is for the current audit period only (1 July 2007 to 30 June 2010). The table has been colour coded to identify sites where cyanobacteria levels reached the green or amber alert ranges specified in the recreational guidelines at least once during the audit period. This is reflected in the maximum values. Two water storage sites in the Kangaroo River – Fitzroy Falls dam wall (DFF6) and Lake Yarrunga at the Bendeela Picnic Area (DTA8) – had relatively high total and potentially toxic cyanobacteria levels. According to the SCA, recreational guidelines were exceeded in Lake Yarrunga at the Bendeela Picnic Area on 3 sampling occasions in May and early June 2009. The samples were dominated by a small celled species of potentially toxigenic Microcystis. Hence, while the biovolume equivalent data indicate much lower cyanobacterial levels (as shown in Table 6.3.1), red alerts were still raised on each occasion (SCA 2009e). Longer-term data show that the levels of potentially toxic cyanobacteria for all the water storages listed in Table 6.3.1 are typically in the green alert range of the recreational guidelines for most years, indicating a continued need for monitoring. Longer-term data for the river monitoring sites show that cyanobacteria levels are typically below or in the green alert range of the recreational guidelines. River sites that are of potential concern are those in the Wollondilly River (E488, E409), Wingecarribee River (E303, E332) and Mulwaree River sub-catchments (E457). Cyanobacteria levels at these sites exceeded the amber or red alert ranges of the recreational guidelines at least once in the current audit period.

Chapter 6 – Water Quality 157 Table 6.3.1: Biovolume equivalents of total and potentially toxic cyanobacteria, and Microcystin LR equivalent in samples collected from rivers and water storages in the Catchment that are used by the general public Biovolume Biovolume equivalent equivalent potentially Microcystin total toxic LR cyanobacteria cyanobacteria equivalent Sub-catchment Site (mm3/L) (mm3/L) (µg/L) Werribee Creek Werriberri Creek @ 0, 0.004 0, 0 No data (River) Werombi (E531) (n = 5) (n = 5) Little River (River) Little River @ Fireroad 0.176, 0.2 0, 0 No data W4I (E243) (n = 3) (n = 3) Nattai River (River) Gibbergunyah Creek @ 0.007, 0.063 0, 0.004 No data Mittagong STP (E203) (n = 15) (n = 15) Nattai River @ 0, 0.033 0, 0 No data Smallwoods Crossing (n = 8) (n = 8) (E210) Upper Nepean Nepean River @ 0.087, 0.353 0.023, 0.085 No data River (River) McGuires Crossing (n = 9) (n = 9) (E697) Wollondilly River Wollondilly River @ 0.039, 3.408 0.0095, 0.469 0.54, 1.3 (River) Joorilands (E488) (n = 26) (n = 26) (n = 7) Wollondilly River @ 0.0065, 0.784 0, 0.013 No data Murrays Flat (E409) (n = 18) (n = 18) Wollondilly River @ 0.001, 0.064 0, 0.001 No data Golden Valley (E450) (n = 7) (n = 7) Wingecarribee Wingecarribee River @ 0.1715, 1.186 0.102, 1.163 0.3, 1.99 River (River) Sheepwash Bridge (n = 134) (n = 134) (n = 134) (E303) Wingecarribee River @ 0.205, 1.211 0.059, 0.839 0.66, 2.44 Berrima Weir (E332) (n = 37) (n = 37) (n = 15) Kangaroo River Lake Fitzroy Falls 0.164, 0.407 0.104, 0.277 0.37, 0.47 (Water Storage) atdam wall (DFF6) (n = 27) (27) (9) Kangaroo River Lake Yarrunga @ 0.0675, 0.648 0.034, 0.646 0.15, 0.36 (Water Storage) Kangaroo River, (n = 76) (n = 76) (n = 58) Bendeela Picnic Area ( DTA8) Kangaroo River Lake Yarrunga @ 0.0355, 0.257 0.024, 0.257 0.15, 0.3 (Water Storage) Kangaroo Arm Reed (n = 38) (n = 38) (n = 14) Island (DTA10) Kangaroo River Lake Yarrunga @ 0.016, 0.07 0.013, 0.068 0.15, 0.15 (Water Storage) Kangaroo and Yarrunga (n = 10) (n = 10) (n = 1) Junction (DTA3) Kangaroo River Lake Yarrunga @ 100m 0.009, 0.011 0.0035, 0.008 No data (Water Storage) from dam wall (DTA1) (n = 6) (n = 6)

158 2010 Audit of the Sydney Drinking Water Catchment Biovolume Biovolume equivalent equivalent potentially Microcystin total toxic LR cyanobacteria cyanobacteria equivalent Sub-catchment Site (mm3/L) (mm3/L) (µg/L) Kangaroo River Kangaroo River @ 0, 0.004 0, 0.004 No data (River) Hampden Bridge (E706) (n = 6) (n = 6) Shoalhaven River @ 0.025, 0.205 0.016, 0.087 0.15, 0.15 D/S Tallowa Dam (n = 13) (n = 13) (n = 2) (E851) Bungonia Creek Lake Yarrunga @ 0.012, 0.255 0.003, 0.252 0.15, 0.15 (Water Storage) Shoalhaven River (n = 17) (n = 17) (n = 2) (DTA5) Shoalhaven River @ 0.0075, 0.837 0, 0 No data Fossickers Flat (E847) (n = 6) (n = 6) Mulwaree River Mulwaree River @ 0.016, 49.92 0.006, 17.74 0.15, 0.15 (River) Towers Weir (E457) (n = 11) (n = 11) (n = 2) Mid Shoalhaven Shoalhaven River @ 0.12, 0.123 0, 0.32 No data River (River) Hillview (E861) (n = 6) (n = 6) Boro Creek (River) Boro Creek @ Marlowe 0.0005, 0.031 0, 0.022 No data (E890) (n = 4) (n = 4) Braidwood Creek Shoalhaven River @ 0, 0 0, 0 No data (River) Mount View (E860) (n = 2) (n = 2) Gillamatong Creek @ 0.003, 0.055 0, 0 No data Braidwood (E891) (n = 7) (n = 7)

Note: Values shown are the median in bold and maximum concentrations; the sample size is shown in brackets. Colour coding corresponds with the green, amber and red alert levels specified for cyanobacteria in the NHMRC (2008) recreational guidelines.

Table 6.3.2 summarises the medians and maximums of total and potentially toxic cyanobacteria and the Microcystin LR equivalent in samples collected from monitoring sites in lakes/reservoirs used to supply drinking water. Note again that the data is only shown for the current audit period. The table has been colour coded to identify sites where cyanobacteria levels reached the ranges specified in the Australian Drinking Water Guidelines (NHMRC and NRMMC 2004) at least once during the current audit period. Hence, those coloured in green indicate that the maximum values for potentially toxic cyanobacteria levels were greater than 500 cells/mL, those in amber indicate maximum values are greater than 2000 cells/mL and those in red indicate maximum values exceed the drinking water guidelines (> 6500 cells/mL). The potentially toxic cyanobacteria levels in all but one (DWA12) site shown for Lake Burragorang exceeded the drinking water guidelines. These results are indicative of the visible cyanobacteria bloom that was first noticed near the Warragamba Dam wall in August 2007, but continued to develop until December 2007 (www.sca.nsw.gov.au/publications/awqmr08/incidents/bgalgae). During this period cell counts of the potentially toxigenic Microcystis reached as high as 800,000 cells/mL (Figure 6.3.2). The SCA suggests that a bloom of this magnitude and duration has never occurred before near the dam wall (SCA 2008a). As shown in Figure 6.3.3, the number of blooms and alerts in Lake Burragorang are typically small.

Chapter 6 – Water Quality 159 The potentially toxic cyanobacteria levels at the outlet of Wingecarribee Reservoir (DWI1) exceeded the drinking water guidelines during the current audit period. The SCA’s additional sampling in response to the exceedances shows that the high levels of potentially toxic cyanobacteria also persisted for extended periods of time (SCA, 2008b). The data showed that in early 2008, the dominant algal species detected in the samples was Microcystis aeruginosa which was the likely cause of the high levels of Microcystin LR equivalent also found in the samples. Longer-term data for the Wingecarribee sites indicate that the drinking water guidelines for potentially toxic cyanobacteria are commonly exceeded at the sites (Figure 6.3.3). The only other site where potentially toxic cyanobacteria levels exceed guidelines was in Bendeela Pondage (DBP1), from where raw water is subsequently supplied to Kangaroo Valley water treatment plant and is pumped to Fitzroy Falls and eventually to the Wingecarribee Reservoir. Longer-term data for this site show a history of relatively high potentially toxic cyanobacteria levels (Figure 6.3.3). Also worthy of mention, are the longer-term data for the remainder of water storage monitoring sites listed in Table 6.3.2, which contained less than 500 cells/mL during the current audit period. All of these sites had levels of potentially toxic cyanobacteria that were either > 500 cells/mL (green) or > 2000 cells/mL (amber) at various periods over the last two decades. Data for an additional 17 water storage monitoring sites, which were not sampled during the current audit period but sampled at various periods show that the majority of the water storages contained > 500 cells/mL (green) or > 2000 cells/mL (amber) of potentially toxic cyanobacteria.

Figure 6.3.2: Counts of total and potentially toxic cyanobacteria at Lake Burragorang, 500 m upstream of Warragamba Dam wall (DWA2) Source: Sydney Catchment Authority data Note: The y-axis is a log scale.

160 2010 Audit of the Sydney Drinking Water Catchment Table 6.3.2: Cell counts of total and potentially toxic cyanobacteria, and Microcystin LR equivalent in samples collected from water storages in the Catchment. Potentially Microcystin Total toxic LR cyanobacteria cyanobacteria equivalent Sub-cathment Site (cells/mL) (cells/mL) (µg/L) Grose River Lower Cascade 832, 25298 0, 109 <0.3, <0.3 Dam (DLCI) (N = 127) (N = 127) (N = 127) Top Cascade Dam 2649, 63470 0, 166 <0.3, <0.3 (DTC1) (N = 161) (N = 161) (N = 130) Greaves Creek 1991, 20110 0, 180 <0.3, 15 Dam (DGC1) (N = 132) (N = 132) (N = 131) Woronora River Lake Woronora @ 1369, 6124 0, 21 <0.3, <0.3 dam wall (DWO1) (N = 46) (N = 47) (N = 12) Upper Nepean Lake Nepean @ 937, 27740 28, 309 <0.3, <0.3 300m U/S dam (N = 20) (N = 20) (N = 11) wall (DNE2) Lake Cordeaux @ 1562, 63660 0, 12 <0.3, <0.3 dam wall (DCO1) (N = 20) (N = 20) (N = 11) Lake Cataract @ 2642, 11440 0, 14 <0.3, <0.3 Dam Wall (DCA1) (N = 20) (N = 20) (N = 12) Lake Avon @ 6160, 29800 0, 28 <0.3, <0.3 Upper Avon Valve (N = 18) (N = 18) (N = 7) Chamber (DAV7) Prospect Lake Prospect @ 3213, 529812 0, 860 <0.3, <0.3 Midlake (RPR1) (N = 335) (N=335) (N = 133) Lake Lake Burragorang 69362, 510712 18188, 510712 <0.3, <0.3 Burragorang @ Wollondilly Arm (N = 11) (N = 11) (N = 1) 23 km U/S dam (DWA27) Lake Burragorang 49670, 336900 2532, 145124 <0.3, <0.3 @ 14 km U/S Dam (N = 35) (N = 35) (N = 4) Wall (DWA9) Lake Burragorang 23402, 380800 571, 114824 <0.3, <0.3 @ 500 m U/S dam (N = 57) (N = 57) (N = 1) wall (DWA2) Lake Burragorang 48395, 219300 218, 5230 No Data @ 9 km U/S Coxs (N = 11) (N = 17) River (DWA12) Wingecarribee Wingecarribee 32451.5, 3125, 34830 0.35, 2.35 River Lake @ Outlet 196300 (N = 250) (N = 239) (DWI1) (N = 250) Kangaroo River Kangaroo River 12147.5, 716.5, 17291 <0.3, 0.37 WFP Raw Water 132256 (N = 152) (N = 152) (DBP1) (N = 152)

Note: Values shown are the median in bold, maximum counts; and sample size (in brackets). Colour coding corresponds with the green, amber and red alert levels specified for cyanobacteria in the Australian Drinking Water Guidelines (NHMRC & NRMMC 2004).

Chapter 6 – Water Quality 161

Figure 6.3.3: Counts of total and potentially toxic cyanobacteria at selected sites in Lake Burragorang (DWA27, DWA9), Wingecaribee Reservoir (DWI1) and Kangaroo River (DBP1) Source: Sydney Catchment Authority data Note: The y-axis is a log scale..

162 2010 Audit of the Sydney Drinking Water Catchment Longer-term data Two main issues arise from the results described above: 1. the recent incidence of the cyanobacteria bloom (predominantly Microcystis) in the Warragamba water supply system 2 the recurrent incidences of cyanobacteria blooms in the Shoalhaven water supply system, which supplies water to the Kangaroo Valley WFP and Warragamba and Nepean dams during times of drought. The SCA’s recent long-term trend analyses indicate increasing cell counts of potentially toxin producing species of cyanobacteria in Lake Burragorang (SCA 2009e). As shown in Figure 6.3.2, this trend is more likely an artefact of the unprecedented cyanobacteria bloom in 2007–08. Investigations into the causes of the bloom indicated that a series of rain events preceding the bloom delivered inflows of approximately 450,000ML, which significantly increased the water level in the dam (by 9 m), but also significantly increased the ambient nutrient concentrations. The increased availability of nutrients, and in particular bioavailable nutrients, has been proposed as one of the main factors for stimulating and maintaining the bloom (SCA, 2008a). Investigations into the potential impact of the Shoalhaven transfers on the cyanobacteria bloom in Lake Burragorang indicate that the volume of water and nutrient loads from the transfers (via Wingecarribee Reservoir) were insignificant compared to the inflows from the surrounding sub-catchments as a result of the rain event (SCA 2008c). The investigations also indicated that the development of the bloom was in situ rather than a result of transport from other locations (i.e. Fitzroy Falls and Wingecarribee reservoirs) known to sustain larger populations of cyanobacteria. A qualitative examination of cell composition in samples collected in Lake Burragorang prior to the Shoalhaven transfers (i.e. prior 2001–02) show that Microcystis species have been present over the years, meaning that the transfers did not necessarily act as a seeding stock for the bloom. The potential impacts of the Shoalhaven transfers on the cyanobacteria populations in Lake Burragorang should not be dismissed altogether, however, given the potential risk when large volumes of water are transferred under low flow conditions. A multivariate analysis comparing the composition of cyanobacteria collected from the Kangaroo River site and from Fitzroy Falls Reservoir indicated that prior to 2001, that is prior to the Shoalhaven transfers, the cyanobacteria composition in samples collected at DBP1 and DFF6 were different (52% average similarity). Post 2001, the cyanobacteria composition in samples collected at DBP1 and DFF6 was more similar (70% average similarity). While the temporal changes cannot be directly attributed to the Shoalhaven transfers, the analysis does highlight a potential risk of mixing of algal species communities from DBP1 and DFF6. The multivariate analysis has also shown that the temporal changes in the cyanobacteria composition at DPB1 and DFF6 are largely dictated by changes in the abundance of families of cyanobacteria that have potentially toxic species, for example, Merismopediaceae, Chroococcaceae and Nostocaceae. This parallels the SCA’s long-term trend analyses, which shows that the abundances of potentially toxin producing species in the Shoalhaven system are increasing (SCA 2009e). Plots showing the putative trends in the potentially toxic cyanobacteria counts for a number of sites in the Shoalhaven system are provided in the trend assessment section of the report (Section 6.4).

Chapter 6 – Water Quality 163 Implications and future directions There is a long history of cyanobacteria blooms in the Catchment. The current audit has highlighted the prevalence of both potentially toxic and non-toxic blooms in the lakes/reservoirs, particularly in the Shoalhaven and Warragamba systems. Cyanobacteria, including potentially toxic species, have been detected in the rivers but for the majority of sites abundances have been low enough to fall below the amber and red alert levels specified in the NHMRC (2008) recreational guidelines. River sites of particular concern, however, include those in the Wollondilly River (E488, E409), Wingecarribee River (E303, E332) and Mulwaree River sub- catchments (E457). Cyanobacteria levels at these sites have at times exceeded the amber or red alert levels specified in the NHMRC (2008) recreational guidelines. The relatively high likelihood of cyanobacteria levels exceeding guidelines in the lakes/reservoirs reflects the inherent ambient environmental conditions (e.g. low flows and turbulence) which are conducive to the growth of cyanobacteria. This means that even in very low numbers there is the potential for blooms to be triggered. One recent example of this is the large persistent bloom in Warragamba Dam in 2007–08. The bloom developed locally, being triggered by large inflows of nutrient rich runoff from the surrounding sub-catchments. This incident reinforces the need to place extra weighting on land use practices that minimise or prevent nutrient exports from the surrounding sub-catchments draining into the lakes/reservoirs. Extra attention should also be given to sub-catchments from which water is being transferred. Previous research has shown that the high concentrations of nutrients (e.g. phosphorus) in water transferred from Lake Yarrunga may stimulate growth of the existing algal biomass in the Fitzroy Falls Reservoir (Sherman and Orr 2003). Any seeding of cyanobacteria as a result of the transfers is suggested (by the SCA) to be unlikely given the high pressure exerted during vertical pumping. Such high pressures apparently cause the cyanobacteria cell vacuoles to collapse and be severely damaged. This audit has, however, pointed to the potential risk of algal mixing under low flow conditions. As such, it is recommended that the risk of algal mixing be further investigated. One simple approach would be to examine the viability of the cyanobacterial cells after pumping from Bendeela Pondage. A clear outcome of the audit is the temporal shift in the composition of cyanobacteria and phytoplankton at numerous sites in the Shoalhaven system. Of concern is the increase in the ratio of potentially toxic to total cyanobacteria shown in the longer- term data. Further analysis of the data, specifically temporal trends in individual species/genera of cyanobacteria and phytoplankton, is required in the future, if trend analyses are to be used as an early warning sign of potential cyanobacterial problems. The Auditor is aware that there is a draft proposal to chemically dose Fitzroy Falls Reservoir to reduce nutrient (and phytoplankton) levels. Any proposal to chemically treat Fitzroy Falls Reservoir must be undertaken carefully and the wider ecological ramifications for species other than phytoplankton species should be considered. For example, care should be taken not to affect populations of the endemic Fitzroy Falls crayfish (Euastacus dharawalus) which appears to be restricted to the Fitzroy Falls catchment (Coughran et al. 2009). Discussions need to be undertaken with the Department of Health and DECCW, prior to finalising the specifics of any chemical dosing proposal.

Recommendation 22: The SCA should investigate the risk of mixing of cyanobacteria between water bodies in the Shoalhaven system during periods of low flow.

Recommendation 23: The SCA should investigate trends and long-term patterns in the community composition of cyanobacteria and phytoplankton in the dams and reservoirs.

164 2010 Audit of the Sydney Drinking Water Catchment 6.4 Trend assessment

Background Assessment of trend was a new requirement for the current audit. Some indicators are insufficiently developed to enable a trend assessment (e.g. wetland condition) while others have not been consistently measured over a timescale long enough or frequent enough to provide a reliable identification of trend (e.g. fish). In order to undertake a meaningful trend assessment there needs to be long-term data on the indicator of interest as well as the major covariates that affect/explain an indicator’s state. DECC (2009b) found that trends in hydrology and water quality in the Hawkesbury– Nepean River needed to be interpreted in terms of both longer-term cycles (e.g. the El Niño Southern Oscillation (ENSO) and Inter-decadal Pacific Oscillation (IPO)) as well as human-induced changes (including the potential for climate change impacts in the future). Although the international scientific community has reached a consensus that global warming is unequivocal (IPPC 2007) the exact implications this has for rainfall and hydrology are far more uncertain, particularly at a regional scale in NSW (DECC 2009b). DECC (2009b), demonstrated that there have been cyclic periods of higher and lower rainfall and flow in the lower Hawkesbury–Nepean River basin and concluded that these trends were likely to continue even under a global warming scenario. In addition, since many water quality variables are significantly affected by flow, assessments of changes and/or trends in water quality need to consider variation in flow. Undertaking a trend assessment throughout the Catchment is a challenging and time-consuming process, particularly in light of the effects of short and long term climatic cycles. As a result, only a relatively simplified assessment of trend could be made in the timeframe available for the current audit. The main approach taken has been to consider the long-term percentiles for hydrology (flow) and water quality variables in different time periods. Flow exceedance curves (empirical cumulative distribution functions) have also been used to identify changes in flow in various time periods. Inferences from these simplistic ‘trend’ assessments need further support by using more sophisticated trend assessments of water quality which account for variation in rainfall and flow. Fortunately this has already been undertaken to some extent for many of the long- term water quality monitoring sites in the Catchment. For example, DECC (2009b) described long-term trends in the Hawkesbury–Nepean River, although this was mostly downstream of Warragamba and Metropolitan dams and reservoirs. UNSW (2009) has undertaken an assessment of long-term trend in water quality at sites in the Shoalhaven catchment. CSIRO Maths and Information Statistics (CMIS) have also undertaken trend assessments for long-term water quality monitoring sites in the Hawkesbury–Nepean River Catchment upstream of the dams. Unfortunately the results from this latter study were not made available to the Auditor.

Findings

Trends based on percentiles A summary of flow and water quality percentiles in the rivers and dams/reservoirs can be found in the various sub-catchment sections (Appendix C) and in Appendix G. Apparent increases or decreases in these medians were checked using time series plots and running medians over the time period of observations. Some apparent trends in water quantity have already been discussed (Chapter 5), however these

Chapter 6 – Water Quality 165 putative trends still need to be verified and related back to variation in rainfall patterns across the Catchment. There was insufficient time in the current audit to complete this checking process. Putative trends based on the medians for water quality are summarised below. These percentiles do not make allowance for differences in flow in the respective periods. Since assessments of changes and/or trends in water quality need to consider variation in flow (DECC 2009b), the putative trends identified here should be used as triggers for further investigations, rather than simply assuming that a real trend exists. More detailed and sophisticated trend analyses are required to understand trend at some sites for some analytes.

River monitoring sites Putative trends in Total Nitrogen (TN) percentiles are suggested for: • a number of sites in the Upper Coxs River sub-catchment (increasing TN levels) • the Coxs River at Kelpie Point (increasing TN levels – see Upper Coxs River sub- catchment summary in Appendix C) • the Keduma River at Maxwells Crossing (decreasing trend due to removal of South Katoomba STP effluent; now stabilised but at relatively high levels) • Woronora at the Needles (increasing TN levels) • the Kangaroo River at Hampden Bridge (increasing TN levels) • the Corang River (decreasing TN levels) • Thompsons Creek Dam (increasing TN levels). TN levels at Werriberri Creek at Werombi, Gillamatong Creek at Braidwood, Lake Wallace and the Shoalhaven River at Mount View require more detailed assessment. Putative trends in Total Phosphorus (TP) percentiles are suggested for the: • Coxs River downstream of Sawyers Swamp Creek to Pipers Flat Creek (increasing TP levels) • Coxs River downstream of Lake Wallace (increasing TP levels) • Coxs River downstream of Marrangaroo Creek (increasing TP levels) • Keduma River at Maxwells Crossing (E157; decreasing trend due to removal of South Katoomba STP effluent; now stabilised but at moderately high levels) • Nattai River at the Crags (decreasing TP levels; see Figure 6.4.1) • Wollondilly River at Murrays Flat (decreasing TP levels from a high point in 2001– 2004) • Kangaroo River at Hampden Bridge (increasing TP levels) • Corang River (decreasing TP levels). Putative trends in chlorophyll-a percentiles are suggested for: • the Wollondilly River at Joorilands (increasing Chlorophyll a levels) • Lake Cordeaux at the Dam Wall (increasing Chlorophyll a levels) • Lake Avon at Upper Avon Dam Chamber (increasing Chlorophyll a levels) • Wingecarribee Lake at Outlet (increasing Chlorophyll a levels) • Lake Fitzroy Falls at Dam Wall (increasing Chlorophyll a levels) • Lake Yarrunga at Kangaroo and Yarrunga Junction (increasing Chlorophyll a levels) • Lake Yarrunga at Shoalhaven River (increasing Chlorophyll a levels; see Figure 6.4.2).

166 2010 Audit of the Sydney Drinking Water Catchment Chlorophyll a levels in Gillamatong Creek at Braidwood and Lake Yarrunga at Kangaroo River/Bendeela Pumping Station need more detailed assessment. Historically, Nerrimunga Creek at Minshull Trig also showed some indications of an increase in medians but there are no recent data to confirm the current state.

Figure 6.4.1: Trend in total phosphorus in the Nattai River at The Crags

Figure 6.4.2: Trend in chlorophyll a in Lake Yarrunga at the Shoalhaven River

Putative trends in conductivity percentiles are suggested for: • a number of sites in the Upper Coxs River sub-catchment (increasing conductivity levels) • the Nattai River at the Crags (increasing conductivity levels) • the Nattai River at Smallwoods Crossing (increasing conductivity levels)

Chapter 6 – Water Quality 167 • the Wollondilly River at Joorilands (decreasing conductivity levels; see Figure 6.4.3) • Gillamatong Creek at Braidwood (increasing conductivity levels). The Wollondilly River at Murrays Flat needs more detailed assessment.

Figure 6.4.3: Trend in conductivity in the Wollondilly River at Joorilands

Putative trends in dissolved oxygen saturation (%) percentiles are suggested for: • the Kedumba River at Maxwells Crossing (increasing dissolved oxygen saturation levels, most likely related to the decommissioning of South Katoomba STP). The Nattai River at The Crags, Wollondilly River at Joorilands and Burke River at the inflow to Lake Nepean require more detailed assessment. Putative trends in filterable reactive phosphorus (FRP) percentiles are suggested for the: • Kedumba River at Maxwells Crossing (decreasing FRP levels, most likely related to the decommissioning of South Katoomba STP) • Nattai River at The Crags (decreasing FRP levels) • Nattai River at Smallwoods Crossing (decreasing FRP levels from a peak in the mid 1990s) • Wingecarribee River at Berrima (decreasing FRP levels) • Wollondilly River at Murrays Flat (decreasing FRP levels from a peak in the 2001–2004 period) • Mulwaree River at Towers Weir (decreasing FRP levels from very high levels in 1998–2001 and 2001–2004). Putative trends in oxidised nitrogen (NOx) percentiles are suggested for the: • Kedumba River at Maxwells Crossing (decreasing NOx levels, most likely related to the decommissioning of South Katoomba STP) • Woronora River at The Needles (increasing NOx levels).

168 2010 Audit of the Sydney Drinking Water Catchment Putative trends in pH percentiles are suggested for: • the Kowmung River (slight decrease in pH levels: see Figure 6.4.4) • the Wollondilly River at Joorilands (decrease in pH levels) • Werriberri Creek at Werombi (decrease in pH levels)

Figure 6.4.4: Trend in pH in the Kowmung River at Cedar Ford

Putative trends in total and/or potentially toxic cyanobacteria are suggested for: • Lake Yarrunga Bendeela Picnic Area (no change in total, increase in potentially toxic cyanobacteria) • the Kangaroo River WFP inflow (no change in total, increase in potentially toxic cyanobacteria) • Lake Fitzroy Falls at dam wall (no change in total, increase in potentially toxic cyanobactria) • Wingecarribee Lake at the outlet (decrease in total, increase in potentially toxic cyanobacteria: see Figures 6.4.5 and 6.4.6). Note: Putative trends for a range of other sites still require assessment.

Chapter 6 – Water Quality 169

Figure 6.4.5: Trend in total cyanobacteria counts at the Wingecarribee Lake outlet

Figure 6.4.6: Trend in potentially toxic cyanobacteria counts at the Wingecarribee Lake outlet

UNSW statistical analysis of water quality data As mentioned earlier, the UNSW analysed water quality data from the Shoalhaven River catchments and reservoirs (they also included Wingecarribee Reservoir in this group). UNSW (2009) considered seventeen analytes at 7 catchment locations (E706, E822, E847, E851, E860, E861 and E890) and 10 Lake locations (DDF, DFF6, DTA1, DTA3, DTA5, DTA8, DTA10, DWI, DWI1 and DWI3). Many of the analytes were the same as those analysed using percentiles above, although it is noted that UNSW did not include electrical conductivity in their list of analytes. A

170 2010 Audit of the Sydney Drinking Water Catchment focus was placed on those sites which had greater than 85 observations over the period of records because of statistical model complexity (UNSW 2009). Results from UNSW’s (2009) analyses indicated significant trends in: • the Mongarlowe River at Mongarlowe (E822) – increasing trend in dissolved oxygen, chlorophyll a and total manganese; decreasing trend in total aluminium • the Shoalhaven River at Fossickers Flat (E847) increasing trend in turbidity, total nitrogen, chlorophyll a and total manganese • the Kangaroo River at Hampden Bridge (E706) – increasing chlorophyll a and total iron levels • the Shoalhaven River downstream of Tallowa Dam (E851) –decreasing trend in turbidity, total nitrogen, total phosphorus, total iron, total aluminium, and total manganese; increasing trend in dissolved oxygen (% saturation) • the Shoalhaven River at Mount View (E860) – increasing dissolved oxygen saturation, total nitrogen and chlorophyll a • the Shoalhaven River at Hillview (E860) – increasing total nitrogen and total manganese • Gillamatong Creek at Braidwood (E891) – decreasing total phosphorus and total aluminium • Wingecarribee Reservoir (DWI1) – increasing turbidity, total iron and total aluminium • Fitzroy Falls Reservoir (DFF6) – increasing turbidity, total iron, total aluminium and chlorophyll a; decreasing dissolved oxygen saturation.

Implications Adaptive management requires monitoring to measure the effectiveness of previous management actions and to better focus subsequent actions. Without such monitoring there is often no measure of ‘success’ or ‘failure’ of the management action. Long-term monitoring programs are rare in an Australian and in the worldwide context. However, they are fundamental to understanding where a system currently is in terms of an underlying natural climate cycle and a range of changes made by humans in the past (DECC 2009b). They are also essential for assessing and understanding long-term trends. An audit of the Catchment would be very difficult to complete without the ongoing monitoring undertaken in the Catchment by the SCA, DECCW, NOW, I&I Fisheries and other data gathering organisations (e.g. CMAs, local councils). The routine Water Quality Monitoring Network undertaken by the SCA contains some of the best long-term series of water data in NSW (and Australia). This is to the credit of the organisation (and its predecessor organisations) and individuals involved in its initial design, implementation and continuance. The data collected up until the present time represent not only a significant historical and ongoing investment, but a very valuable resource in terms of long-term information on water quality and quantity in the Hawkesbury–Nepean and Shoalhaven River catchments. The Auditor notes the review of SCA’s water quality monitoring program during the current audit period and that, over time, there is a continuing reduction in the sampling effort (sites/number of samples) or breadth of analytes measured. While this is perhaps inevitable in an era of competing priorities, the Auditor considers the current expenditure on water monitoring program to be more than compensated for by the understanding of how much water is in these systems and what its quality is. Further without this data, only limited assessments of trend and the effectiveness of

Chapter 6 – Water Quality 171 management actions with respect to water quality can be undertaken. While modelling is often used to fill gaps in knowledge and make inferences across a wider catchment area than that currently monitored/measured, all such models require local monitoring data for calibration and validation. As models change or get updated, the requirement for up-to-date monitoring data remains. During the current audit period a number of more obvious ‘trends’ were identified using simple percentiles. Decommissioning of STPs (e.g. South Katoomba STP) and upgrades to other STPs (e.g. Mittagong (Braemar)) have led to a decrease in nutrients and, in some cases, an increase in dissolved oxygen saturation levels in the streams. Notwithstanding these trends, nutrient levels in many streams downstream of STPs still have relatively high nutrient levels. This suggests that further nutrient reduction programs at the STPs are still required if the community expectation is that nutrient levels should move closer to ANZECC guideline levels. In contrast to nutrients, the salt load from STPs appears to be increasing in some areas (e.g. Gillamatong Creek, Gibbergunyah Creek and Nattai River). This is also the case downstream of Delta Electricity’s blowdown discharge where conductivity levels are now well above ANZECC guidelines. Recent research has shown the potential for such elevated conductivity levels to affect in-stream biota (Kefford et al. 2010; DECCW 2010b). This and previous audits have identified gaps in the monitoring network where, in some cases, whole sub-catchments remain unmonitored for flow and/or water quality. While this may be deemed appropriate for areas experiencing relatively small to no anthropogenic impacts (e.g. mostly protected catchments such as the Endrick River sub-catchment), this does not apply to other sub-catchments (e.g. Nerrimunga River) where historic data indicate water quality is poor and may be deteriorating. Without long-term data it will remain difficult to identify trends in the unmonitored catchments. The SCA should therefore look very closely at including monitoring sites in sub-catchments that currently have no long-term water quality or flow gauging sites. From the monitoring data that is available, a number of trends are apparent from analyses undertaken in the current audit (percentiles; running medians) and previous statistical treatments of the data (e.g. UNSW 2009). The Auditor is aware that trend assessments for many sites in the Hawkesbury–Nepean Catchment upstream of the dams have also been undertaken (CSIRO), but the results from these analyses were not available to the Auditor. While there is some agreement between the results of the trend analyses considered here, the trend question needs more detailed work and a unifying summary of all trends in water quality across the Catchment. Where trend assessments indicate a decline in water quality (e.g. increasing nutrient levels, metal levels, conductivity, chlorophyll a and potentially toxic cyanobacteria or decreasing dissolved oxygen saturation), the reasons behind these declines need to be established. This should lead to management action to arrest the decline and help improve water quality at these sites.

Recommendation 24: The SCA should look very closely at including monitoring sites in sub-catchments that currently have no long-term water quality or flow gauging sites.

Recommendation 25: The SCA collate all recent work undertaken on water quality trend assessments and provide a unifying summary of trends in water quality across the Catchment.

172 2010 Audit of the Sydney Drinking Water Catchment 6.5 Integration of water quality and ecosystem health indicators In the preceding sections, assessment of indicators has, in most cases, been treated in isolation. This is primarily due to differing methodologies and the different sites and times that each indicator has been sampled. The Auditor considers that there is considerable scope for indicator monitoring in the catchment to be integrated into a broader ecosystem health monitoring program. This would extend to sampling water quality and ecosystem health indicators at the same sites and/or times in the Catchment. This would provide a more comprehensive understanding of stream and catchment health and enable a more focussed and better prioritised management response to catchment condition. Where data exists in several unconnected agency databases (e.g. macroinvertebrates), the SCA in cooperation with other State and Local Government Agencies should investigate ways of integrating this information into a comprehensive database(s) on ecosystem health indicators for the Catchment. The SCA should ensure these databases are readily available to be used in future audits and/or other programs relying on assessments of catchment health.

Recommendation 26: The SCA in cooperation with other state and local government agencies explore ways to integrate individual monitoring programs into a broader ecosystem health monitoring program for the entire Catchment.

Recommendation 27: The SCA in cooperation with other state and local government agencies investigate ways of integrating their respective ecosystem health databases so that a common comprehensive database on ecosystem health indicators is developed for the Catchment.

Recommendation 28: The SCA ensure these combined databases are readily available to be used in future catchment audits and/or other programs relying on assessments of catchment health.

Chapter 6 – Water Quality 173 Chapter 7 Audit Recommendations

7.1 Overview The purpose of this concluding chapter is: • to record the outcomes of recommendations from the 2007 audit • record new recommendations arising out of the 2010 audit • compile all the above recommendations into a single summary that can support the successful delivery of future catchment audits.

7.2 Review of the 2007 recommendations The 2007 audit made a number of recommendations aimed at improving knowledge and the assessment of Catchment Health. The SCA provided a detailed response on how these recommendations have been addressed over the subsequent audit period. The SCA’s response to these recommendations has been included in Table 7.2.1. The Auditor notes the significant amount of work that the SCA has undertaken in addressing the recommendations in the intervening time period since the last audit. The SCA has indicated that many of the 2007 recommendations are now ‘complete’. The Auditor’s view is, however, that in relation to catchment management using an adaptive management approach, management actions are rarely ever complete. Continued monitoring and research inform and feed back into the adaptive management assessment and help focus the next round of management responses. Most problems in the catchment have been known for a considerable period of time and require a long-term approach to their solution (e.g. erosion control, riparian rehabilitation). New or changing pressures also necessitate a change in management response, particularly where recent monitoring suggests changes are occurring and that these changes are moving in an undesirable direction (e.g. declining trend in water quality). Audits also need to take account of changing pressures and the state of the catchment and the level of knowledge that has been gained over the intervening audit period. This has led to new or more specific recommendations in Chapters 2 to 7 above. These recommendations are summarised in Section 7.3.

174 2010 Audit of the Sydney Drinking Water Catchment Table 7.2.1: SCA’s response to the 2007 audit recommendations Catchment audit Status at 30 June 2010 recommendations

2005/3 (carried over to 2007) – The In progress. SCA examine the potential for, and In 2009 the SCA undertook a review of the SCA’s benefits of, integrating ecosystem water monitoring program as required under its water quality, macroinvertebrate, fish Operating Licence. The review was finalised in (when developed) and riparian December 2009 and the 2010–2015 Water vegetation condition monitoring Monitoring Program was implemented in January programs. 2010. A number of changes were made at this time to the program and its monitoring and analytical 2007/8 – The SCA should review its contracts. water quality and macroinvertebrate The program is to be reviewed after one year from monitoring program to ensure that implementation. This review will include a thorough appropriate integrated ecosystem risk assessment of each site and will be informed by monitoring is undertaken in all sub- the Catchment to tap risk assessment and catchments. Catchment Decision Support outputs. Any monitoring undertaken by other agencies within the SCA area of operations will be documented to avoid duplication. The review of the macroinvertebrate monitoring program (MMP) undertaken by SKM in 2009 provided recommendations on improvements to the program and integrated monitoring options which may provide better insight into changes and trends in river health. Action is now underway to: ▪ commence the first annual review of the 2010– 2015 Water Monitoring Program which will be complete in early 2011 ▪ revise the MMP in line with the SKM review recommendations. ▪ integrate the macroinvertebrate monitoring contracts and data storage into the broader water monitoring program. Further consideration will be given to the cost effectiveness and benefits of integrating the water quality and macroinvertebrate monitoring programs. 2005/5 (carried over to 2007) – The Complete. SCA focus its programs for nutrient The SCA is focusing on the Wingecarribee, reduction from diffuse sources on the Wollondilly and Mulwaree rivers as priorities for Wingecarribee River (priority), nutrient reduction. Wollondilly River (priority), and The SCA has developed the Healthy Catchments Mulwaree River (priority) sub- Strategy (HCS) which identifies the top 100 pollution catchments, and encourage other sources in the Catchment, and uses a CDSS to organisations undertaking related prioritise responses and focus resources on programs to focus on these same catchment issues that pose the highest risk to water sub-catchments where possible. quality (with particular focus on nutrients and pathogens). The HCS, implemented through the Healthy Catchments Program (HCP) includes programs for nutrient reduction from diffuse sources and programs working in partnership with other organisations. The SCA’s rural lands and sewage programs include actions to reduce nutrients from diffuse sources in the Wingecarribee, Wollondilly and Mulwaree sub-

Chapter 7 – Audit Recommendations 175 Catchment audit Status at 30 June 2010 recommendations catchments. Under the rural lands program, the SCA is: ▪ working with dairy farmers and the dairy industry to target dairy waste in the Wingecarribee sub- catchment ▪ providing assistance to landholders in the Wollondilly and Wingecarribee sub-catchments as part of the SCA’s Riparian Management Assistance Program (RMAP) ▪ promoting sustainable grazing in the Wingecarribee, Wollondilly and Mulwaree sub- catchments, in conjunction with the Department of Industry and Investment (formerly the Department of Primary Industries). Under the SCA’s Sewage Program, the SCA is: ▪ working with Wollondilly and Wingecarribee councils to improve sewer performance in the Wollondilly and Wingecarribee sub-catchments ▪ providing grants and training to Wingecarribee Council to improve management of on-site wastewater management systems. 2005/6 (carried over to 2007) – The Complete. SCA identify the cause of exceedance The SCA, NSW Health and Sydney Water of the Bulk Water Supply Agreement investigated the cause of exceedances. The for turbidity, pH and algae at water prevailing drought conditions were responsible for filtration plants. some exceedances and increased algal activity can result in high pH at Prospect. The SCA’s Warragamba Blue–green Algal Action Plan includes a range of actions to prevent, minimise, manage and respond to algal activity. Raw water turbidity can increase due to heavy rainfall carrying sediments washed in from catchment land. Turbidity spikes may occur during rainfall although compliance monitoring by the SCA indicates that turbidity levels generally remain within the required site-specific standards. Guideline values in the BWSA are based on water filtration capacity. The quality of the water supplied did not compromise the ability of the water filtration plants to produce water to meet drinking water guidelines. 2005/16 (carried over to 2007) – The Complete. SCA and Department of Planning The SCA has undertaken a land use mapping prepare a detailed land use map at project to map changes from 2004 to 2009. The five year intervals. The resolution and latest aerial photography (2008–09) and satellite categorisation should be sufficient so imagery were used as datasets. that change from the previous map The outcomes from this project will be: can be determined. ▪ a 2009 land use dataset ▪ a comprehensive dataset of land use history from 2000 to 2009 ▪ knowledge of emerging land use issues in the catchments. Land use mapping was completed in 2010.

176 2010 Audit of the Sydney Drinking Water Catchment Catchment audit Status at 30 June 2010 recommendations

2005/18 (carried over to 2007) –The Complete. SCA develop pollution prevention or The SCA has developed the HCS, which utilises the rehabilitation programs at sites CDSS to assess all known pollution sources and identified at very high, high and prioritise them for action, then develop a range of medium risk to water quality based on initiatives to address the top 100 priorities over the catchment audit, in consultation with next three years. Catchment audit outcomes are relevant agencies, operators and considered in the priority setting for the HCS. The landholders. HCS was finalised in 2010. The Healthy Catchments Program (HCP) provides details of the initiatives and projects that were implemented in 2009/10. Relevant agencies, operators and landholders are consulted as part of the development of the HCS and HCP. 2005/19 (carried over to 2007) – The Complete. DNR [NOW] develop systems in Southern Rivers CMA and Hawkesbury–Nepean consultation with the SCA for CMA have partnered with DECCW to undertake a recording the location, nature and comprehensive assessment of salinity impacts and extent of actual cases of soil erosion risks. This analysis is complete and provides and land salinity in the Catchment. detailed analysis of salinity risks and understanding of groundwater and surface water interactions in the Catchment. 2005/24 (carried over to 2007) – The Complete. NSW DPI [I&I NSW] in consultation The Department of Industry and Investment has with SCA, develop a fish community several current projects collecting fish community monitoring program for the Catchment data in the Catchment. to assist the management of aquatic The NSW Government’s Monitoring Evaluation and ecosystem health. Reporting (MER) has collected data on fish communities from 36 randomly selected sites in the Hawkesbury–Nepean Catchment in November 2007, followed by 14 sites in the Sydney–Wollongong Coast regions and 10 sites in the Shoalhaven Catchment in November 2008. The design of the freshwater fish MER can report at the zone (coastal fringe, lowlands, slopes, uplands and highlands), catchment and CMA scales. Sites are selected randomly from a modelled stream network representing available freshwater fish habitat in NSW. Sampling in each CMA area is repeated every three years. Field teams sample each site between 1 October and 30 April and apply standardised sampling protocols to collect fish community data. In conjunction with this, the SCA provided funding for the Pheasants Nest Fishway assessment project, the Tallowa Dam High Fishway assessment project and the Nepean River fish passage improvement assessment project to address the issue of fish passage in SCA catchment areas and to monitor the response of fish populations to fish passage facilities at a number of SCA-managed weirs and dams.

Chapter 7 – Audit Recommendations 177 Catchment audit Status at 30 June 2010 recommendations

2005/25 (carried over to 2007) – The Complete. DNR, DEC (DECCW) and SCA jointly The SCA developed a Vegetation Condition Index undertake vegetation condition (VCI) to map the condition of vegetation in the mapping of areas outside the Special catchments. The VCI uses satellite imagery to Areas. calculate relative healthiness of vegetation, taking into account changes over time to determine an average condition that can be mapped. A negative deviation from the average condition suggests some sort of disturbance to the vegetation. The SCA’s VCI has a water quality and quantity focus. 2007/1 – The operators and Complete. regulator(s) of the sewage treatment DECCW continues to actively regulate licensed systems in the Catchment should sewage treatment systems in the catchment. The continue efforts to reduce current SCA has established a targeted inspection program levels of nutrient loads discharged for Sewage Treatment Plant (STP) effluent disposal into the Catchment. and package STPs. The SCA is working with councils to upgrade of STPs and effluent reticulation systems through the Accelerated Sewerage Program. Improvements in the levels of nitrogen and phosphorus are tracked and identified as plants are completed and commissioning is completed. Construction, investigation and design works on STPs in the catchments included Braidwood, Bundanoon, Taralga, Lithgow, Wallerawang, Kangaroo Valley, Robertson and the upper Blue Mountains. 2007/2 – The SCA should continue Complete. the process of understanding the The SCA has had an ongoing commitment to causes of the high incidences of algal understanding the causes of algae in reservoirs. blooms in the water storages of the Following the algal bloom in Lake Burragorang in Kangaroo River (priority), August 2007, the SCA developed the Warragamba Wingecarribee River (priority) and Dam Blue–green Algal Action Plan. The plan Lake Burragorang sub-catchments, to includes actions to prevent or minimise algal blooms help ensure that specific management across the catchments, including: strategies are in place for the short, ▪ investigations into the causes of the 2007 blue– medium and long term in each sub- green algal bloom in Lake Burragorang, which catchment. identified the main factors as moderate inflow having optimal timing (winter cooling cycle) and a low initial storage volume relative to inflow volume. Comprehensive technical reports were prepared and externally reviewed ▪ investigations into alternative control options, including solar powered water mixing devices ▪ hazard assessment and prioritisation of catchment actions under the Healthy Catchment Strategy involving pollution source hazard ranking (catchment decision support system) ▪ a comprehensive research program has been established to investigate the environmental factors leading to blooms and the release of toxins and the factors that mediate the breakdown of toxins, and taste and odour-

178 2010 Audit of the Sydney Drinking Water Catchment Catchment audit Status at 30 June 2010 recommendations producing compounds in the SCA reservoirs ▪ extension of the SCA’s reservoir management system into storages in the Shoalhaven system. The reservoir model incorporates water quality modelling capability. Whilst the algae plan was focused on Lake Burragorang, the SCA is developing a broader Cyanobacteria Strategy building upon the work undertaken under the Warragamba Dam Blue– Green Algae Action Plan, and relevant to all reservoirs including Wingecarribee Reservoir and Lake Yarrunga. 2007/3 – The SCA should investigate Complete. the causes of the continuing In 2008–09 a 10-year review of all available data presences of pathogens in the Nattai from Cryptosporidium and Giardia monitoring sites River (Gibbergunyah Creek), and the was undertaken. Monitoring sites in the Nattai River, Wollondilly River, Mid Coxs River and Wollondilly River, Mid Coxs River and Werriberri Werriberri Creek (priority) sub- Creek sub-catchments were included. The review catchments. found that all catchment sites, other than Gibbergunyah Creek, indicated negligible to low levels of Cryptosporidium. Braemar STP discharges treated effluent upstream of the Gibbergunyah Creek monitoring site. The STP includes ultraviolet disinfection as part of the treatment process, which renders Cryptosporidium oocysts non-infective. Protozoa continue to be detected immediately downstream of the plant however these are unlikely to be viable live oocysts. Current laboratory tests for identifying Cryptosporidium are unable to distinguish between living and non-living oocysts. Targeted investigations into the causes of periodically elevated pathogen levels in Gibbergunyah Creek to confirm the source and validate the UV disinfection efficacy of the STP have occurred. These found that the continuing presence of Cryptosporidium is a direct result of the STP discharge and that as long as the plant is functioning effectively, Cryptosporidium is being treated effectively. The SCA has undertaken hazard assessments of all potential pathogen sources across its catchments (CDSS) as part of the HCS, and provided a grant to UNSW researchers to undertake a relative STP pathogen risk assessment. The SCA will now be undertaking a monitoring needs study of pathogen loads downstream of selected STPs. 2007/4 – The SCA should undertake Complete. sampling for the presence of The SCA, NSW Health and Sydney Water revised pathogens in the Kangaroo River the joint Cryptosporidium and Giardia monitoring (priority) sub-catchment. program which focuses on monitoring raw water at supply points and treated water. There is no routine monitoring for Cryptosporidium and Giardia in the Kangaroo River sub-catchment. The program

Chapter 7 – Audit Recommendations 179 Catchment audit Status at 30 June 2010 recommendations includes a wet weather auto sampler for Cryptosporidium and Giardia within the Kangaroo River sub-catchment. Bacterial pathogens are routinely monitored at various sampling sites in Lake Yarrunga under the SCA's Water Monitoring Program. 2007/6 – The SCA, DECC [DECCW] Complete. and CMAs should undertake The SCA is working with the Department of Industry programs that address soil erosion and Investment to deliver education and training to and salinity in the areas with identified graziers on best management practices through the and observed risk, and integrate them Sustainable Grazing Program (SGP). The SGP with other programs for riparian and addresses grazing management practices, including vegetation management where a number that reduce soil erosion and salinity. possible. Over 1400 graziers will have now participated in the SGP. An ongoing evaluation of outcomes from the program is being conducted. The evaluation focuses on learning outcomes, intention to adopt new practices and practices that have been adopted for participants in the PROGRAZE and LANDSCAN courses. Evaluation progress reports have been completed. The SCA has commenced a pilot grants program in partnership with the Hawkesbury–Nepean and Southern Rivers CMAs to implement learnings from the SGP. The SCA also provides financial support to graziers through the Department of Industry and Investment to provide tools to assess improvements in pasture cover. The SCA is working with the CMAs to deliver the Catchment Protection Scheme (CPS). The CPS is designed specifically to address soil erosion. The SCA jointly funds the program, along with the catchment management authorities, Department of Lands and landholders As part of the CPS, Hawkesbury–Nepean Catchment Management Authority addressed severe gully, stream bank and stream bed erosion in priority areas across the Warragamba catchment. These projects also integrated riparian and vegetation management programs and outcomes. Outputs and outcomes of current and past projects can be found in SCA’s Annual Catchment Management Reports. Through the CPS, the Southern Rivers Catchment Management Authority worked closely with the SCA on implementing river restoration projects in the Kangaroo Valley. They also partnered with the DECCW to undertake a comprehensive assessment of salinity impacts and risks. The Southern Rivers Catchment Management Authority wetland and native vegetation projects are complementary to SCA objectives, delivering on both water quality and biodiversity outcomes. 2007/7 – The SCA should investigate Complete. the reasons and drivers for declines in An independent review of the macroinvertebrate

180 2010 Audit of the Sydney Drinking Water Catchment Catchment audit Status at 30 June 2010 recommendations both water quality and monitoring program (MMP) has been undertaken macroinvertebrate health in those and has found that the ecological condition of the sub-catchments where declines have majority of the 27 sub-catchments is highly variable been documented. in both temporal and spatial scales. However, long-term averages for core sites indicate that all of SCA’s sub-catchments are generally in good ecological condition with the poorest sub- catchments only scoring marginally below the reference condition threshold. Trend analyses of the ecological condition at each site indicate that very few sites show a consistent decline in macroinvertebrate health. Due to lack of water quality data at those sites that do have a consistent decline in macroinvertebrate health (Reedy Creek, Coxs River at Lidsdale, Nattai River at the causeway and Wollondilly River at Goonagulla) it is difficult to ascertain the drivers behind the decline. The MMP review has provided some recommendations regarding the implementation of an integrated monitoring approach which may provide a better insight into the drivers. The following are potential pollutant sources upstream of these locations: ▪ Reedy Creek – Gully and streambank erosion, (total suspended solids (TSS)) ▪ Nattai River above the Causeway – STP (Pathogens), intensive animals (total phosphorous(TP)), On-sites (TP) ▪ Upper Wollondilly River above Goonagulla – Horticulture (TP, total nitrogen (TN), and TSS) ▪ Coxs River above Lidsdale – Only rated as moderate risk areas for (TP, TN, TSS). Actions under the HCS to address potential causes of the decline in water quality and macroinvertebrate health in the identified sub-catchments are being undertaken. These include: ▪ riparian works at Reedy Creek as part of the CPS ▪ a planned upgrade to the sewage treatment plant at Wallerawang in the Upper Cox’s ▪ training and inspections to improve nutrient and effluent management on dairy farms ▪ continued assistance to Wingecarribee Shire Council to inspect on-site wastewater management systems in the Nattai catchment ▪ working collaboratively with DECCW to assess the source and fate of metals and salinity in the Upper Coxs River ▪ assessment of the pathogen risk from Braemar STP is underway.

Chapter 7 – Audit Recommendations 181 Catchment audit Status at 30 June 2010 recommendations

2007/9 – The SCA should undertake In progress. follow-up monitoring at The MMP samples all core sites, including those macroinvertebrate monitoring which have recorded lower AusRiVAS ratings. The locations that have significantly MMP review found some bias in the selection of impaired or severely impaired roaming sites and this may have skewed the results AusRivAS ratings. for some sub-catchments. The review recommended replacing roaming sites with more randomly selected core sites. Monitoring of existing core sites will continue. The SCA is currently considering the recommendations from the review, and has suspended the monitoring of roaming sites in the interim. 2007/12 – The SCA, DECC [DECCW] Complete. and CMAs should work together to The SCA and Hawkesbury–Nepean and Southern establish a spatial information system Rivers CMAs have been working to share data to track and record information on all stored on the DECCW Land Management Database. on-ground works being undertaken or The database tool was developed with combined funded by Government for the input from the CMAs, DECCW and in consultation purposes of water quality and with the SCA. It has been adopted state wide by all ecosystem health management in the CMAs, DECCW and the Department of Industry and Catchment. Investment. All paper records on the CPS works carried out in the Hawkesbury–Nepean Catchment Management Authority area of operations since around 1960 have been stored in the Land Management Database and shared with the SCA. The SCA has provided $60K to the Southern Rivers Catchment Management Authority to complete the same work for their area of operations. In November 2008 the NSW Government launched the Spatial Centre of Excellence, which via programs such as Common Spatial Information Initiative, C2Si, includes a focus on how spatial frameworks can be developed or extended to promote shared services.

182 2010 Audit of the Sydney Drinking Water Catchment 7.3 Recommendations from the 2010 audit The following 28 recommendations have arisen in the preceding chapters and sections of this report, and from the overall conduct of the 2010 audit. Where relevant, particular sub-catchments to which the recommendations apply are identified. The Auditor commends these recommendations to the Minister, for subsequent referral to the relevant parties for their consideration and appropriate action.

Audit Methodology Recommendation 1: The SCA investigate ways to achieve effective Aboriginal community engagement in the audit prior to the commencement of the next Sydney Drinking Water Catchment audit.

Land Use and Human Settlements Recommendation 2: The Department of Planning should undertake detailed consideration of the potential cumulative impacts of all mining activities within the SCA Special Areas. Recommendation 3: Where significant streams and wetlands in the Catchment are impacted by longwall mining there should be a requirement that these impacts are remediated at the expense of the mining company. Recommendation 4: DECCW review licence limits in the Upper Coxs River sub- catchment for all licensed discharge points with a view to reducing the heavy metal and salinity concentrations and loads being discharged to the Coxs River catchment. Recommendation 5: The SCA, HNCMA and SRCMA develop a consistent baseline map of gully erosion for the Catchment.

Biodiversity and Habitats Recommendation 6: The SCA continue to undertake follow-up monitoring at macroinvertebrate monitoring locations that have scored an AusRivAs rating of significantly impaired, severely impaired or extremely impaired where there is no obvious driver for an impacted rating. Recommendation 7: DECCW, in collaboration with SCA, develop a consistent, uniform and integrated vegetation dataset that covers the entire Sydney Drinking Water Catchment. Recommendation 8: The Rural Fire Service, in cooperation with SCA and DECCW, integrate their spatial datasets across all sub-catchments so that a single, consistent estimate for the area burnt by hazard reduction burns and bushfires can be reported. Recommendation 9: Lithgow City Council and Centennial Coal should ensure that water transfers from the Clarence Water Transfer Scheme are piped around, rather than flow through, Farmers Creek Swamp. Recommendation 10: DECCW finalise its Draft Upland Swamp Environmental Assessment Guidelines in order to achieve consistency in the application of risk assessment methodology for swamps over areas of longwall mining in the Catchment.

Chapter 7 – Audit Recommendations 183 Recommendation 11: DECCW and the SCA should finalise their classifications of wetlands to produce a complete and consistent coverage of wetlands in the Catchment.

Water Availability Recommendation 12: NOW should investigate the reasons behind the recent decline in flow in Werriberri Creek. Recommendation 13: The SCA reinstate the flow gauging station in the Little River at Fire Road W4I. Recommendation 14: DECCW, SCA, I&I and NOW investigate the possibility of establishing a collaborative research program aimed at providing a better understanding of the surface water and groundwater hydrology of Thirlmere Lakes and its catchment. Recommendation 15: NOW should investigate the reasons behind the apparent long- term decline in flow in Reedy Creek. Recommendation 16: NOW should finalise the Draft Water Sharing Plan for the Greater Metropolitan Region as soon as practicable. Recommendation 17: NOW and SCA undertake research aimed at understanding the extent, connectivity and interaction between sub-surface aquifers (confined and unconfined), perched aquifers and surface waters within the Catchment.

Water Quality Recommendation 18: The SCA undertake a targeted survey of pesticide usage and application in the catchments of Cascade Dam and Wingecarribee Reservoir. Recommendation 19: The SCA continue to investigate the cause of persistent detections of Cryptosporidium and Giardia oocysts/cysts in the Catchment. Recommendation 20: The operators and regulators of sewage treatment systems in the Catchment should continue efforts to reduce nutrient loads. Recommendation 21: Estimates of nutrient loads from diffuse sources should be included in future audits in order to understand the full context of nutrient loading in the Catchment. Recommendation 22: The SCA should continue to investigate the risk of mixing of cyanobacteria between water bodies in the Shoalhaven system during periods of low flow. Recommendation 23: The SCA should investigate trends and long-term patterns in the community composition of cyanobacteria and phytoplankton in the dams and reservoirs. Recommendation 24: The SCA should look very closely at including monitoring sites in sub-catchments that currently have no long-term water quality or flow gauging sites. Recommendation 25: The SCA collate all recent work undertaken on water quality trend assessments and provide a unifying summary of trends in water quality across the Catchment.

184 2010 Audit of the Sydney Drinking Water Catchment Integration of Water Quality and Ecosystem Health Indicator Monitoring Recommendation 26: The SCA in cooperation with other state and local government agencies explore ways to integrate individual monitoring programs into a broader ecosystem health monitoring program for the entire Catchment. Recommendation 27: The SCA in cooperation with other state and local government agencies investigate ways of integrating their respective ecosystem health databases so that a common comprehensive database on ecosystem health indicators is developed for the Catchment. Recommendation 28: The SCA ensure these combined databases are readily available to be used in future catchment audits and/or other programs relying on assessments of catchment health.

Chapter 7 – Audit Recommendations 185 Acronyms

ABC – Australian Broadcasting Corporation ACARP – Australian Coal Association Research Program ADWG – Australian Drinking Water Guidelines ALUM – Australian Land Use and Management API – Aerial Photograph Interpretation ANZECC – Australian and New Zealand Environment and Conservation Council APVMA – Australian Pesticides and Veterinary Medicines Authority ARMCANZ – Agriculture and Resource Management Council of Australia and New Zealand ASU – Area Standard Unit AusRivAS – Australian River Assessment System AWT – Australian Water Technologies BHPBIC – BHP Billiton–Illawarra Coal BLR – Basic Landholder Rights BMCC – Blue Mountains City Council BOD – Biological Oxygen Demand BOM – Bureau of Meteorology BWSA – Bulk Water Supply Agreement CAP – Catchment Action Plan CDSS – Catchment Decision Support System CMA – Catchment Management Authority CMIS – CSIRO Maths and Information Statistics CPS – Catchment Protection Scheme CRCWQT – Cooperative Research Centre for Water Quality and Treatment CSIRO – Commonwealth Scientific and Industrial Research Organisation DairySAT – Dairy Self Assessment Tool DAPI – 4',6-diamidino-2-phenylindole DEC – Department of Environment and Conservation DECC – Department of Environment and Climate Change DECCW – Department of Environment, Climate Change and Water DEH – Department of Environment and Heritage DEWHA – Department of Environment, Water, Heritage and Arts DII – Department of Industry and Investment DIPNR – Department of Infrastructure, Planning and Natural Resources DIWA – Directory of Important Wetlands in Australia DLWC – Department of Land and Water Conservation DMR – Department of Mineral Resources DNR – Department of Natural Resources DNRMQ – Department of Natural Resources and Mines - Queensland DOH – Department of Housing

186 2010 Audit of the Sydney Drinking Water Catchment DoP – Department of Planning DPI – New South Wales Department of Primary Industries D/S – Down Stream DWE – Department of Water and Energy EA – Environmental Assessment EASI – Environmental Assessment of Sites and Infrastructure ENSO – El Nino Southern Oscillation EPA – Environment Protection Authority EP&A Act – Environment Planning and Assessment Act FRP – Filterable Reactive Phosphorus GEM – Grants, Evaluation and Monitoring GIS – Geographic Information System HCP – Healthy Catchments Program HCSR – Health Care Service Record HNCMA – Hawkesbury–Nepean Catchment Management Authority HNRMF – Hawkesbury Nepean River Management Forum HRB – Hazard Reduction Burn I&I Fisheries – The NSW Department of Industry and Investment - Fisheries IPPC – International Plant Protection Convention IPO – Inter-decadal Pacific Oscillation LEP – Local Environmental Plan LGA – Local Government Area LMD – Land Management Database LTAAEL – Long-term Average Annual Extraction Limit MER – Monitoring Evaluation and Reporting Strategy M-SC RACC – Metropolitan and South Coast Regional Algal Coordinating Committee MMP – Macroinvertebrate Monitoring Plan Mt – Million tonnes NCC – Nature Conservation Council of NSW NDVI – Normalised Difference Vegetation Index NOx – Oxidized Nitrogen NOW – NSW Office of Water NHMRC – National Health and Medical Research Council NorBE – Neutral or Beneficial Effect NOW – NSW Office of Water NP – National Park NPWS – National Parks and Wildlife Service NR – Nature Reserve NRM – Natural Resources Management NSW – New South Wales NTU – Nephelometric Turbidity Units OEM – Outside the Experience of the Model OHN – Office of the Hawkesbury-Nepean

Acronyms 187 PAC – Planning Assessment Commission POEO Act – Protection of the Environment Operations Act PSR – Pressure-State-Response PWG – Parks and Wildlife Group RACC – Regional Algal Coordinating Committee RCI – Riparian Connectivity Index REP – Regional Environmental Plan RFS – Rural Fire Service RMAP – Riparian Management Assistance Program RMZs – Risk Management Zones RNWS – Raising National Water Standards RSoER – Regional State of the Environment Report RUSLE – Revised Universal Soil Loss Equation RVI – Riparian Vegetation Index SASPoM – Special Areas Strategic Plan of Management SCA – Sydney Catchment Authority SCIVI – South Coast – Illawarra Vegetation Integration Project SEPP – State Environment Planning Policy SMCMA – Sydney Metropolitan Catchment Management Authority SOC – Synthetic Organic Compounds SoE – State of the Environment SRA – Sustainable Rivers Audit SRCMA – Southern Rivers Catchment Management Authority STP – Sewage Treatment Plant STS – Sewage Treatment System TLGE – Total Licensed Groundwater Entitlement TM – Thematic Mapper TN – Total Nitrogen TP – Total Phosphorus TSC – Threatened Species Conservation Act UNSW – University of New South Wales U/S – Upstream VCI – Vegetation Condition Index WCA – Wetland Care Australia WFP – Water Filtration Plant WRC – Water and Rivers Commission WSP – Water Sharing Plan WSSAPoM – Wingecarribee Swamp and Special Area Plan of Management

188 2010 Audit of the Sydney Drinking Water Catchment References

ABC (2009) Herbicides in Hobart water 'a public health risk', ABC News. Accessed 26 October 2010, ABS (2010a) Census Data. Last updated 29 January 2010. Accessed 27 October 2010, ABS (2010b) 3218.0 – Regional Population Growth, Australia, 2008–09. Last updated 30 March 2010. Accessed 27 October 2010, ACARP (2006) Techniques to predict and measure subsidence and its impacts on the ground water regime above shallow longwalls. Australian Coal Association Research Program, Final Report C13009, March 2006. ANZECC/ARMCANZ (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand. Canberra. Armstrong, J. L., and Mackenzie, D.H. (2002) Sediment yields and turbidity records from small upland subcatchments in the Warragamba Dam Catchment, southern New South Wales. Aust. J. Soil Res., 40: 557-579 Aurecon. (2009a). Newnes Plateau Shrub Swamp Management Plan – Investigation of Irregular Surface Movement within East Wolgan Swamp. Centennial Coal. 26 June 2009. Report Reference: 7049-010-Rev 3. Aurecon (2009b) Lithgow Sewerage System Modelling and Assessment. Final Report Vol 1 & 2. Lithgow City Council. June 2009. Reference 28013/08. Aurecon (2009c). Groundwater Response Strategy – Investigation of Anomalous Groundwater Behaviour. Baal Bone Colliery Reference 24596-003. AWT (2000). Investigation of the impact of bed cracking on water quality in the Cataract River. Prepared for the Department of Land and Water Conservation, Sydney South Coast Region. Australian Water Technologies Report No. 2000/0366. AWT (2003) Observed rates of contaminant export from the Lake Burragorang and Nepean Catchments. Prepared for the Sydney Catchment Authority. Australian Water Technologies Report No. 2003/0062. BHPBIC (2009) Dendrobium Area 2 Longwall 4 Swamp 1 Update Report: 7 April 2009. DECCW 2009. Second Submission, Environmental Assessment, Bulli Seam Operations Project Application Number: 08 0150. BHPBilliton (2009). Bulli Seam Operations – Environmental Assessment. BHP Billiton Illawarra Coal Holdings Pty. Ltd. Booth, C.J., Spande, E.D., Pattee, C.T., Miller, J.D. and Bertsch, L.P. (1998), ‘Positive and negative impacts of longwall mine subsidence on a sandstone aquifer’. Environmental Geology, vol. 34, pp. 223-233.

References 189 Booth, C.J. (2002), ‘The effects of longwall mining on overlying aquifers’, in Younger, P.L. & Robins N.S. (eds), Mine Water Hydrogeology and Geochemistry, Geological Society London, Special Publications, vol. 198, pp. 17-45. Booth, C.J. (2006), ‘Groundwater as an environmental constraint of longwall coal mining’, Environmental Geology, vol. 49, pp. 796-803. Booth, C.J. (2007), ‘Confined-unconfined changes above longwall coal mining due to increases in fracture porosity’, Environmental & Engineering Geoscience, vol. 13, no. 4, pp. 355-367. Boulton A.J, Humphreys W.F and Eberhard S.M. (2003). Imperilled Subsurface Waters in Australia: Biodiversity, Threatening Processes and Conservation, Aquatic Ecosystem Health & Management, 6(1): 41-54. Braideck, TE. and Karlin, RJ. (1985) Causes of Waterborne Giardiasis Outbreak. In Giardia lamblia in water supplies – Detection, Occurrence and Removal. An AWWA Technical Resource book. American Water Works Association. Brierley. G., Nanson, R., Ferguson, R., and Crighton, P. (1999) River Styles in the Shoalhaven Catchment, South Coast, NSW. Report to the NSW Department of Land and Water Conservation. Brierley, G. and Fryirs, K. (2005) Geomorphology and River Management; Application of the River Style Framework. Blackwell Publishing. Brown, J. (1972). Hydrologic effects of a bushfire in a catchment in south-eastern New South Wales, Journal of Hydrology 15: 77–96. Centennial Coal (2009) Springvale Colliery Subsidence Management Status Report. Four Monthly Update. 7th March 2009. Chafer (2007) Wildfire, Catchment Health and Water Quality: a review of knowledge derived from research undertaken in Sydney’s Water Supply Catchments 2002- 2007. Chessman, B.C (1995) Rapid assessment of rivers using macroinvertebrates – A procedure based on habitat-specific sampling, family level identification and a biotic index. Australian Journal of Ecology (1995) 20(1): 122-129. Coughran, J., McCormack, R.B. and Daly, G. (2009). Translocation of the Yabby Cherax destructor into eastern drainages of New South Wales, Australia. Australian Zoologist 35, 100-103. CRCFE (2000) Scope of Sustainable Rivers Audit. Report prepared by Cullen, P., Harris, J., Hillman, T., Liston, P., Norris, R., and Whittington, J. for the Coorperative Research Centre for Freshwater Ecology, Canberra, ACT. CRCWQT (2007a) Pathogen Movement and Survival in Catchments, Groundwaters and Raw Water Storage, Drinking Water Facts, Cooperative Research Centre for Water Quality and Treatment, Canberra, ACT. CRCWQT (2007b) Cryptosporidium Genotyping and Ineffectivity Analysis, Drinking Water Facts, Cooperative Research Centre for Water Quality and Treatment, Canberra, ACT. DEC (2003) 2003 Audit of the Sydney Drinking Water Catchment. Report to the Minister for the Environment, NSW Government. Department of Environment and Conservation NSW, Sydney. DEC (2005) 2005 Audit of the Sydney Drinking Water Catchment. Report to the Minister for the Environment, NSW Government. Department of Environment and Conservation NSW, Sydney.

190 2010 Audit of the Sydney Drinking Water Catchment DEC (2006) The Vegetation of the Western Blue Mountains. Unpublished report funded by Hawkesbury–Nepean Catchment Management Authority. Department of Environment and Conservation, Sydney. DECC (2007a) 2007 Audit of the Sydney Drinking Water Catchment. Report to the Minister for Climate Change, Environment and Water, NSW Government. Department of Environment and Climate Change NSW, Sydney. DECC (2007b). Submission on the strategic review of the impacts of underground mining in the Southern Coalfield 30 July 2007. Attachment 1. Ecological Impacts of Longwall Mining in the Southern Coalfields of NSW – A Review. Scientific Services Section, Department of Environment and Climate Change. DECC (2008) NSW Scientific Committee—Final Determination, Alteration to the Natural Flow Regimes of Rivers, Streams, Floodplains and Wetlands—Key Threatening Process Declaration, NSW Department of Environment and Climate Change, viewed 14 September 2010, DECC (2008) Riparian zone degradation resulting from the alteration of natural water flow regimes of rivers, streams, floodplains and wetlands has been listed as key threatening processes in NSW under the Threatened Species Conservation Act 1995. DECC (2009a) NSW Diffuse Source Water Pollution Strategy. Department of Environment and Climate Change NSW, Sydney South. ISBN 978 1 741229615 DECC (2009b). Hawkesbury-Nepean River Environmental Monitoring Program. Final Technical Report. February 2009. NSW Department of Environment and Climate Change, Sydney. DECCW (2009a). Second Submission to the BHP Bulli Seam Environmental Assessment. NSW Department of Environment, Climate Change and Water. 16 December 2009. DECCW (2009b) The Native Vegetation of the Sydney Metropolitan Catchment Management Authority Area (Vol 1 & 2). Unpublished report funded by the Australian Government and the Sydney Metro Catchment Management Authority. Department of Environment, Climate Change & Water, Hurstville. DECCW (2010a). Aboriginal Cultural Heritage Consultation Requirements for Proponents 2010. Department of Environment, Climate Change and Water NSW. DECCW (2010b). Draft Coxs River Catchment - Water Quality and Macroinvertebrate Communities. Monitoring Unit – Waters & Coastal Science Section, Scientific Services, Department of Environment, Climate Change and Water. DECCW (2010c) Department of Environment, Climate Change and Water NSW. 2010. NSW Wetlands Policy. Sydney, New South Wales. DECCW (2010d) Report on Farmers Creek Lithgow, June 2010. Internal DECCW Report. DECCW (2010e) Review of Piezometer Monitoring Data in Newnes Plateau Shrub Swamps and their relationship with Underground Mining in the Western Coalfield. NSW Department of Environment, Climate Change and Water. January 2010. DEH (2005) Department of the Environment and Heritage (DEH) 2005, Nationally threatened Species and Ecological communities: Temperate Highland Peat Swamps on Sandstone, Australian Government. Dela-Cruz, J. and Scanes, P. (2009). Estuarine Decision Support. Report to National Action Plan for Salinity and Water Quality, and Natural Heritage Trust.

References 191 Diaz-Fierros, F., Benito Rueda, E. and Perez Moreira, P. (1987). Evaluation of the U.S.L.E. for the prediction of erosion in burnt forest areas in Galicia (N.W. Spain), Catena 14: 189–199. DIPNR (2003). Hydrological and water quality assessment of the Cataract River; June 1999 to October 2002: Implications for the management of longwall coal mining. NSW Department of Infrastructure, Planning and Environment, Wollongong. DLWC (2001) Geomorphic Categorisation of Streams in the Hawkesbury Nepean Catchment. Department of Land and Water Conservation. DMR. (2003). Guideline for applications for subsidence management approvals. NSW Department of Mineral Resources. December 2003. DNRMQ (2002). River Water Quality in the Pioneer Catchment on February 14-15, 2002. Water Quality Assessment and Protection Natural Resource Sciences. Department of Natural Resources and Mines Queensland, July 2002. DoP (2007) South Coast Regional Strategy 2006–2031. State of New South Wales through the Department of Planning, Sydney, Accessed 26 October 2010, DoP (2008a) Sydney–Canberra Corridor Regional Strategy 2006–2031. Department of Planning NSW, Sydney. Accessed 26 October 2010, DoP (2008b). Impacts of Underground Coal Mining on Natural Features in the Southern Coalfield – Strategic Review. New South Wales Government. ISBN 978 0 7347 5901 6. DoP (2010a) New South Wales Statistical Local Area Population Projections, 2006- 2036. Department of Planning, Sydney. DoP (2010b) NSW SLA Population Projections, 2006-2036. LGA Summary Version 1.0. Last updated 2010. Accessed 27 October, 2010, DPI (2008) Degradation of native riparian vegetation along NSW water courses, NSW Department of Primary Industries, viewed September 2008 DPI (2009) East Bargo Expression of Interest Information, Southern Coalfield, New South Wales June 2009. NSW Department of Primary Industries. DSEWPaC (2010) Temperate Highland Peat Swamps on Sandstone. Last updated 5 February 2010. Accessed 27 October 2010. Emery, K. (1986) Rural Land Capability Mapping 1:100000 scale. Department of Land and Water Conservation, Sydney. Environment Australia (2001). A Directory of Important Wetlands in Australia, Third Edition. Environment Australia, Canberra. Galvin and Associates. (2005). A risk study and assessment of the impacts of longwall mining on Waratah Rivulet and surrounds at Metropolitan Colliery. Commissioned by NSW Department of Primary Industries. Report No: 0504/17-1c. March 2005.

192 2010 Audit of the Sydney Drinking Water Catchment Gehrke, P.C. and Harris, J.H. (2001). Regional-scale effects of flow regulation on lowland riverine fish communities in New South Wales, Australia. Regulated Rivers: Research and Management 17, 369-391. Geoterra (2006). Centennial Tahmoor. Longwall Panels 24 to 26 Surface water and groundwater subsidence management plan. Tahmoor, NSW. Report No. TA4-R1B 9 March 2006. Gibbins (2003) Gibbins, L. 2003. A Geophysical Investigation of Two Upland Swamps, Woronora Plateau, NSW, Australia. Honours Thesis, Macquarie University. Goulburn Mulwaree (2010) Goulburn Mulwaree Regional State of the Environment Report (RSoER) 2004-2009. Growns, Pollard and Gehrke (1998) Changes in river fish assemblages associated with vegetated and degraded banks, upstream of and within nutrient-enriched zones. Fisheries Management and Ecology, 5: 55–69. doi: 10.1046/j.1365- 2400.1998.00086.x. Hawkesbury–Nepean River Management Forum (2004) Water and Sydney’s Future. Balancing the Values of our Rivers and Economy. Final Report of the Hawkesbury–Nepean River Management Forum. NSW Department of Infrastructure, Planning and Natural Resources, Sydney. Helensburgh Coal (2008). Metropolitan Coal Project – Environmental Assessment. Helensburgh Coal Pty Ltd. HNCMA (2010) Field Sheets on Arthursleigh University of Sydney. Hawkesbury- Nepean Catchment Management Authority, Goulburn. HNCMA (2009) Hawkesbury–Nepean Catchment Management Authority. Annual Report 2008–09, Hawkesbury–Nepean Catchment Management Authority, Goulburn HNCMA. Sydney Catchment Authority and Hawkesbury Nepean Catchment Management Authority - Catchment Protection Scheme Annual Report for the period July 2007 – June 2008. A report prepared by Aaron Smith, Catchment Coordinator, Hawkesbury Nepean Catchment Management Authority. HNCMA. Sydney Catchment Authority and Hawkesbury Nepean Catchment Management Authority - Catchment Protection Scheme Annual Report for the period July 2008 – June 2009. A report prepared by Aaron Smith, Daniel Hartwell and Lauren Wilson. Industry and Investment NSW (2009) Bringing Back the Fish – Improving Fish Passage and Aquatic Habitat in Coastal NSW. Final Report to the Southern Rivers Catchment Management Authority. Industry and Investment NSW, Cronulla, NSW. IPCC (2007) The AR4 Synthesis Report. International Panel on Climate Change, November 2007, Valencia Spain. Kefford, B.A., Schafer, R.B., Liess, M., Goonan, P, Metzeling, L. and Nugegoda, D. (2010) A similarity index-based method to estimate chemical concentration limits protective for ecological communities. Environmental Toxicology and Chemistry, Vol. 29, No. 9, pp. 2123–2131. Keith, D. (2004) Ocean Shores to Desert Dunes: The native vegetation of NSW and the ACT. NSW Department of Environment and Conservation, Hurstville. Keith, D., Rodoreda, S., Holman, L. and Lemmon, J. (2006) Monitoring Change in Upland Swamps in Sydney’s catchments: the roles of fire and rain. A report undertaken by the Department of Environment and Conservation, funded by the

References 193 Special Areas Strategic Management Research & Data Program. Sydney Catchment Authority. Keith, D.A., Rodoreda, S and Bedward, M. (2010) Decadal change in wetland– woodland boundaries during the late 20th century reflects climatic trends Global Change Biology 16: 2300–2306. Kingsford, R.T. (2000) Ecological impacts of dams, water diversions and river management on floodplain wetlands in Australia. Austral Ecology 25, 109-127, Kingsford, R.T., Brandis, K., Thomas, R.F., Knowles, E., Crighton, P., Gale, E. (2004) Classifying landform at broad landscape scales: the distribution and conservation of wetlands in New South Wales, Australia. Marine and Freshwater Research 55, 17-31. Krogh, M. (2007) Management of Longwall Coal Mining Impacts in Sydney’s Southern Drinking Water Catchments. Australasian Journal of Environmental Management, 14, 155-165. Krogh M, Davison A, Miller R, O’Connor N, Ferguson C, McClaughlin V and Deere D. (2008) Effects of Recreational Activities on Source Water Protection Areas - Literature Review. WSAA Occasional Paper No. 22. Water Services Association of Australia, Melbourne, Australia. Land and Water Australia (2002) Guidelines for Protecting Australian Waterways, report prepared by Bennett J, Sanders N, Moulton D, Phillips N, Lukacs G, Walker K and Redfern F. for Land and Water Australia. Leitch, C. J., Flinn, D. and van de Graaff, R. (1983) Erosion and nutrient loss resulting from Ash Wednesday (February 1983) wildfires: a case study, Australian Forestry 46: 173-180. Littleboy, M., Sayers, J., and Dela-Cruz, J. (2009) Hydrological modelling of coastal catchments in New South Wales. 18th World IMACS / MODSIM Congress, Cairns, Australia 13-17 July 2009 Madden, A. and Merrick, N.P. (2009) Extent of longwall mining influence on deep groundwater overlying a Southern Coalfield mine. pp 176-186 in IAH NSW, Groundwater in the Sydney Basin Symposium, Sydney, NSW, Australia, 4-5 Aug. 2009, W.A. Milne-Home (Ed) ISBN 978 0 646 51709 4. Madden, A. and Ross, J.B (2009) Deep Groundwater Response to Longwall Mining, Southern Coalfield, New South Wales, Australia. pp 187-245 in IAH NSW, Groundwater in the Sydney Basin Symposium, Sydney, NSW, Australia, 4-5 Aug. 2009, W.A. Milne-Home (Ed) ISBN 978 0 646 51709 4. MSEC (2007). Illawarra Coal Dendrobium Mine Area 3. Report No. MSEC311 Revision D. October 2007. Mine Subsidence Engineering Consutlants. NCC (2003) Flows and Fire Regime, Nature Conservation Council of NSW, Sydney, NSW. NHMRC (2004) National Water Quality Management Strategy. Australian Drinking Water Guidelines 6. National Health and Medical Research Council and Natural Resource Management Ministerial Council. Australian Government, ACT. pp 10-2. NHMRC (2008) Guidelines for Managing Risks in Recreational Water. National Health and Medical Research Council. Australian Government, ACT. pp 91-117. NHMRC and NRMMC (2004) Australian Drinking Water Guidelines 6 National Water Quality Management Strategy. National Health and Medical Research Council and Natural Resource Management Ministerial Council. ISBN: 186496118X

194 2010 Audit of the Sydney Drinking Water Catchment NOW (2009) Development of Catchment Health: indicators for the drinking water catchments – Sydney, the Illawarra, Blue Mountains, Southern Highlands and Shoalhaven. New South Wales Office of Water. ISBN 978-0-7313-3439-1. NOW (2010a) Draft Water Sharing Plan for the Greater Metropolitan Region unregulated river water sources: background document May 2010 ISBN 978 1 74263 044 1. [NOTE: copyright is to State of New South Wales through the Department of Environment, Climate Change and Water, 2010] NOW (2010b) Guidelines for surface water sharing plan report cards. NSW Office of Water ISBN 978 0 7313 3446 9. NOW (2010c). Draft Water Sharing Plan Greater Metropolitan Region groundwater sources. Background document. May 2010. ISBN 978 1 74263 050 2. NPWS (1997) Thirlmere Lakes National Park New Plan of Management. NSW National Parks and Wildlife Service. November 1997. NPWS (2003) The native vegetation of the Woronora, O’Hares and Metropolitan Catchments. Unpublished report to the Sydney Catchment Authority. NSW National Parks and Wildlife Service, Hurstville. NPWS, DEC and SCA (2007) Wingecarribee Swamp and Special Area Plan of Management 2007 (WSSAPoM). National Parks and Wildlife Service, Department of Environment and Conservation, Sydney Catchment Authority. NSW Fisheries 2003 Why Do Fish Need to Cross the Road? Fish Passage Requirements for Waterway Crossings. Report prepared by Fairfull, S. and Witheridge, G. for NSW Fisheries, Cronulla, NSW. NSW Government (2004) Official Notices 21 May 2004. NSW Government Gazette 87: 3099. NSW Government (2005) Official Notices 16 December 2005. NSW Government Gazette 157: 11031. NSW Government (2007a) Official Notices 2 February 2007. NSW Government Gazette 24: 636-637. NSW Government (2007b) Official Notices 8 June 2007. NSW Government Gazette 76: 3699. NSW Minerals Council. (2009) Key Industry Statistics 2009. New South Wales Minerals Council Ltd. Sydney NSW Planning Assessment Commission (2009) The Metropolitan Coal Project Review Report NSW Planning Assessment Commission. Sydney NSW Australia ISBN 978-0-9806592-0-7 NSW Scientific Committee (2002) Alteration to the natural flow regimes of rivers, streams, floodplains & wetlands - key threatening process listing. NSW Scientific Committee - final determination. OHN and SCA (undated) Hawkesbury-Nepean River Environmental Flows and Weirs Project. Improving river health and fish passage in the Hawkesbury-Nepean River. Office of the Hawkesbury-Nepean and Sydney Catchment Authority. Patterson Britton & Partners (2006) Southern Highlands Geomorphology Report. Shoalhaven River Water Supply Transfers and Environmental Flows. Issue No. 3. August 2006. Department of Commerce. Prosser, I. P. and Williams, L. (1998) The effect of wildfire on runoff and erosion in native Eucalyptus forest. Hydrological Processes, 12:251-265

References 195 Roser, D., (2008) Stage 1 SCA Relative risk for sewage treatment plant effluent, Stage 3 Report UNSW Water Research Centre. 102 pages these are listed but not referenced specifically in the text Roser, D., van der Akker, B., Ashbolt, N., & Stuetz, R., (2010) Estimating the relative risk from sewage treatment plant effluent, Stage 3 Report UNSW Water Research Centre. 271 pages these are listed but not referenced specifically in the text Rustomji, P. (2006) Modelling sediment and nutrient budgets in the Lake Burragorang catchment: Report to the Sydney Catchment Authority. CSIRO Land and Water Science Report 57/06. Canberra: CSIRO. Rustomji, P.K. and Hairsine, P.B. (2006) Revegetation of water supply catchments following bushfire: A review of the scientific literature relevant to the Lower Cotter catchment. CSIRO Land and Water Science Report 9/06 April 2006. SCA (2000) Sydney Catchment Authority.Pollution Risk Management Plan, prepared by Gutteridge, Haskins and Davey Pty Ltd for SCA, Sydney, NSW. SCA (2002) Dams of Greater Sydney and Surrounds: Blue Mountains. Sydney Catchment Authority. SCA (2003) Sydney Catchment Authority. 2003. Annual Environment Report 2002– 2003. SCA (2005) Water Quality Risk Management Framework, Sydney Catchment Authority, NSW. SCA (2007a) Sydney Catchment Authority Strategic Plan of Management 2007 (SASPoM) SCA (2007b) Wingecarribee Swamp and Special Area Plan of Management 2007 (WSSAPoM). A report prepared for the Sydney Catchment Authority and the Department of Environment and Conservation (DEC). SCA (2007c) Sustaining the Catchments. The Regional Plan for the drinking water catchments of Sydney and adjacent regional centres. Regional Plan – Overview September 2007. Department of Planning and Sydney Catchment Authority and ISBN: 978-1-876951-32-0 SCA (2008a) Warragamba Blue-Green Algae Bloom 2007: Characterisation of the Event (Incident Report). Sydney Catchment Authority, Sydney. SCA (2008b) Sydney Catchment Authority Annual Water Quality Monitoring Report 2007-08. Sydney Catchment Authority, Sydney. SCA (2008c) SCA Technical Report-7. Investigations into the potential impact of Shoalhaven transfers on blue-green algae blooms in Warragamba Dam. Sydney Catchment Authority, Sydney. SCA (2008d) Sydney Catchment Authority Management Report 2007 – 2008. SCA (2009a) Sydney Catchment Management Authority. Annual Catchment Management Report 08-09 SCA (2009b) Prioritising Catchment Actions - The Catchment Decision Support System 2009-2010. Sydney Catchment Authority SCA (2009c) Catchment Protection Scheme. Last updated 16 December 2009. Accessed 27 October, 2010,

196 2010 Audit of the Sydney Drinking Water Catchment SCA (2009d) Media Release. 11 August 2009. Let’s Keep Sweeping the Broom. Southern Rivers Catchment Management Authority. SCA (2009e) Sydney Catchment Authority Annual Water Quality Monitoring Report 2008-09. Sydney Catchment Authority, Sydney. SCA (2009f) Screening Level Risk Assessment of Pesticides and Synthetic Organic Compounds in SCA Catchments. October 2009. Sydney Catchment Authority. SCA (2009) Healthy Catchments Program. Last Updated 16 December 2009. Accessed 26 October, 2010, SCA (2010a) Sydney Catchment Authority. Healthy Catchments Program 2009 – 2010. SCA (2010b) Sydney Catchment Authority. Healthy Catchments Strategy 2009 – 2012. Scott, D. and Van Wyk, D. (1990) The effects of wildfire on soil wetability and hydrological behaviour of an afforested catchment. Journal of Hydrology 121: 239–256. Shakesby, R.A., S.H. Doerr, and R.P.D. Walsh (2000) The erosional impact of soil hydrophobicity: Current problems and future research directions. J. Hydrol. (Amsterdam) 231–232:178–191. Shakesby, R.A., Chafer, C.J., Doerr, S.H., Blake, W.H., Humphreys, G.S., Wallbrink, P. & Harrington, B.H. (2003) Fire severity, water repellency characteristics and hydrogeomorphological changes following the Christmas 2001 forest fires. Australian Geographer 34, 147-175. Shakesby, R.A., Blake, W.H., Doerr, S.H., Humphreys, G.S., Wallbrink, P. and Chafer, C.J. (2006) Hillslope soil erosion and bioturbation following the 2001 forest fires near Sydney, Australia. In Owens, P. and Collins, A. (eds) Soil erosion and soil redistribution in river catchments: measurement, modelling and management in the 21st century. CAB International, Wallingford, 51-61. Sherman, B.S., and Orr, P.T. (2003) Review of nutrients in the Shoalhaven catchments. CSIRO Land and Water, Canberra. SKM (2007) Impacts of Longwall Mining on Surface Water and Groundwater, Southern Coalfield NSW. Sinclair Knight Merz P/L. SKM (2009) Review of Sydney Catchment Management Authorities Macroinvertebrate Monitioring Programe (MMP) Final Report to the Sydney Catchment Management Authority, September 2009. Southern Highland News (2010) Coal mine at Sutton Forest. Ben McCllellan 16 Aug, 2010 SRCMA Catchment Protection Scheme – Upper Shoalhaven and Kangaroo Valley Catchments. 2007/2008 Annual Report. A report prepared by Frank Exon, Catchment Officer (Sustainable Land Use) Braidwood. SRCMA Catchment Protection Scheme – Upper Shoalhaven and Kangaroo Valley Catchments. 2008/2009 Annual Report. A report prepared by Frank Exon, Catchment Officer (Sustainable Land Use) Braidwood. Teunis, P. F. M., Chappell, C. L. & Okhuysen, P. C. (2002a) Cryptosporidium dose response studies: Variation between hosts. Risk Analysis 22, 475-485. Teunis, P. F. M., Chappell, C. L. & Okhuysen, P. C. (2002b) Cryptosporidium dose response studies: variation between isolates. Risk Analysis 22, 175-183.

References 197 Thornton, T.E. (2006) Hexazinone use on Maine’s Blueberry Growing Regions: Environmental Impacts to Surface Water and Groundwater from 1983-2005.MSc. Thesis The University of Maine. August, 2006 Tindall, D., Pennay, C, Tozer, M. Turner, K. & Keith, D. (2004) Native vegetation map report series. No. 4. (Department of Infrastructure Planning and Natural Resources: NSW) Tomkins, K.M. and Humphreys G.S. (2006) Evaluating the effects of fire and other catastrophic events on sediment and nutrient transfer within SCA Special Areas. Technical Report 2. Upland swamp development and erosion on the Woronora Plateau during the Holocene. Sydney Catchment Authority – Macquarie University Collaborative Research Project. Tozer, M.G., Turner, K., Keith, D.A, Tindall, D., Pennay, C., Simpson, C., and MacKenzie, B. (2010) Native vegetation of southeast NSW: a revised classification and map for the coast and eastern tablelands. Cunninghamia (2010) 11(3): 359-406. Turak, E., Flack, L.K, Norris, R.H, Simpson, J. and Waddell (1999) Assessment of river condition at a large spatial scale using predictive models. Freshwater Biology, 41 (2) 283 – 298. Turak, E. & Waddell, N. (2000) Development of AUSRIVAS models for New South Wales, New South Wales Environment Protection Authority, Goulburn Street Sydney, NSW. Turak, E., Hose, G.G. & Waddell, N. (2004) "Reproducibility of AUSRIVAS Rapid Bioassessments Using Macroinvertebrates"", Journal of the North American Benthological Society, vol. 23, no. 1, pp. 126-139. UNSW (2009) Statistical Analysis of Water Quality Data. Phase 1, Project Report 4: Statistical Procedures Implementation in the Shoalhaven Supply System and Catchments. Collaborative Research Project: SCA & UNSW. 10 August 2009. Wilkinson, S., Wallbrink, P., Hancock, G., Blake, W., Shakesby, R.A. and Farwig, V. (2007) Impacts on water quality by sediments and nutrients released during extreme bushfires: Report 4: Impacts on Lake Burragorang. Report for the Sydney Catchment Authority. CSIRO Land and Water Science Report 6/07. February 2007 CSIRO Land Wingecarribee Shire Council (2009) Wingecarribee Shire Council State of the Environment Report 2008/09 WRC (2003) Groundwater, Water and Rivers Commission, WA. Young, A. R. M. (1982) Upland swamps (dells) of the Woronora Plateau, N.S.W. PhD thesis, University of Wollongong.

198 2010 Audit of the Sydney Drinking Water Catchment www.environment.nsw.gov.au