Audit of theSydney Drinking Water Catchment

Report to theMinister for the EnvironmentNSW State Government

December 2005

Audit of theSydney Drinking Water Catchment

Report to theMinister for the EnvironmentNSW State Government

December 2005

Published by:

Department of Environment and Conservation NSW 59–61 Goulburn Street PO Box A290 Sydney South 1232

Phone: (02) 9995 5000 (switchboard) Phone: 131 555 (environment information and publications requests) Phone: 1300 361 967 (national parks information and publications requests) Fax: (02) 9995 5999 TTY: (02) 9211 4723

Email: info@environment.nsw.gov.au Website: www.environment.nsw.gov.au

ISBN 1 74137 739 0 DEC 2005/627 December 2005

Contents

Executive Summary Recommendations Chapter 1 Introduction ................................................................................................................................... 1

1.1 Terms of reference for the Audit ..............................................................................................................1

1.2 Purpose of the Audit ................................................................................................................................2

1.3 Audit methodology ...................................................................................................................................2

1.4 Relationship of the Audit to other processes ............................................................................................6

1.5 Audit Team ...............................................................................................................................................7

1.6 Audit Steering Committee ........................................................................................................................7

1.7 Report on recommendations in the 2003 Audit report..............................................................................7

Chapter 2 Raw Water Quality .................................................................................................................... 15 Key Points ...................................................................................................................................................... 15 Pressures in the Catchment ......................................................................................................................... 16

2.1 Nutrient load ...........................................................................................................................................16

State of the Catchment ................................................................................................................................. 28 2.2 Raw water quality requirements for water filtration plants ...................................................................28

2.3 Algal blooms ..........................................................................................................................................30

2.4 Pathogens ...............................................................................................................................................37

Actions and Response.................................................................................................................................... 41 Response to issue .........................................................................................................................................41

Gaps in the response ....................................................................................................................................46

Chapter 3 Managing Water Resources ...................................................................................................... 47 Key Points ...................................................................................................................................................... 47 Pressures in the Catchment .......................................................................................................................... 48

3.1 Surface water extraction .........................................................................................................................48

3.2 Ground water extraction .........................................................................................................................52

State of the Catchment.................................................................................................................................. 55 3.3 Water for the Environment .....................................................................................................................55

Actions and Response.................................................................................................................................... 61 Response to issue ..........................................................................................................................................61

Gaps in the response ....................................................................................................................................63

Chapter 4 Land Condition ........................................................................................................................... 65 Key Points ...................................................................................................................................................... 65 Pressures in the Catchment ......................................................................................................................... 66

4.1 Changes in land use ................................................................................................................................66

4.2 Sites of pollution and potential contamination .......................................................................................69

State of the Catchment ................................................................................................................................. 76 4.3 Soil erosion. ............................................................................................................................................76

4.4 Dryland Salinity .....................................................................................................................................77

Actions and Response.................................................................................................................................... 79 Response to issue .........................................................................................................................................79

Gaps in the response ....................................................................................................................................85

Chapter 5 Ecosystem Health ....................................................................................................................... 87 Key Points ...................................................................................................................................................... 87 Pressures in the Catchment ......................................................................................................................... 88 State of the Catchment . ................................................................................................................................ 89

5.1 Ecosystem water quality .........................................................................................................................89

5.2 Macroinvertebrates .................................................................................................................................92

5.3 Fish..........................................................................................................................................................94

5.4 Riparian vegetation .................................................................................................................................99

5.5 Native vegetation ..................................................................................................................................101

Actions and Response.................................................................................................................................. 104 Response to issue .......................................................................................................................................104

Gaps in the response ..................................................................................................................................108

Bibliography................................................................................................................................................. 111 Acronyms ..................................................................................................................................................... 119 Appendix A .................................................................................................................................................. 121 Appendix B................................................................................................................................................... 123 Appendix C .................................................................................................................................................. 125 Appendix D .................................................................................................................................................. 127 Appendix E................................................................................................................................................... 133

Executive Summary

The Sydney Water Catchment Management Act 1998 requires that an audit of the state of the land of the Sydney Drinking Water Catchment area be undertaken every two years, and that a report on the audit be submitted to the Minister for the Environment. This is the fourth Audit Report with previous reports published by CSIRO in 1999 and 2001 and by DEC in 2003.

This audit examines the 16,000 square kilometres of the Sydney drinking water catchment, including the Special Areas around storages and the outer catchment areas. The audit has used a pressure-state-response model examining 16 indicators to provide a snapshot of the Catchment condition over the period 1 July 2003 to 30 June 2005. The audit also assesses change in Catchment condition and pressure since previous audit periods where data permits, and reports on responses to recommendations in the 2003 Audit Report.

The auditor found that:

• parts of the Catchment are in good condition especially around the Special Areas • the Wingecarribee, Kangaroo and Wollondilly River sub-catchments are subject to the most pressures,

causing poor conditions for some indicators • the presence of pathogens is a concern at some locations • the incidence of algal blooms is a concern at some locations • better data is needed to determine the Catchment condition for surface and groundwater extraction, soil

erosion, dryland salinity, fish communities, and condition of riparian and native vegetation • catchment monitoring programs need to be better integrated to improve the potential to establish links

between cause and Catchment condition • the integration of management and response programs need to be continued to ensure efficiency.

The Audit Report makes 25 recommendations in response to these findings. The recommendations can be categorised as either general, specific to an indicator and sub-catchment, or related to data needs or better integration of monitoring programs.

The auditor acknowledges that the Catchment is in a state of prolonged drought conditions, and that the drought may have significant effects on several of the indicators reported in this audit. While there are no specific data to assist in quantifying these effects in the Catchment the Audit Report comments on this likely effect where appropriate.

The auditor found that there has been a response completed or initiated in relation to 19 of the 25 recommendations in the 2003 Audit Report. The 2005 Audit Report repeats the outstanding recommendations, or intent of these recommendations, where they remain relevant.

Importantly for future audits, the auditor considers there is significant scope to integrate this audit process with both the natural resource management auditing framework currently being established by the Natural Resources Commission and the existing NSW State of the Environment reporting process. In considering the potential to integrate these processes, the auditor also suggests that the frequency of the audits be extended so that changes in catchment state can be considered in the context of longer timeframes. Further, to improve the process for future audits, the auditor should be appointed as soon as possible to enable the audit methodology and indicators to be set, and arrangements for data collection and provision to be agreed with relevant organisations at the start of the audit period.

Table ES1 shows the sub-catchments that this Audit found to be under pressure. A blue dot indicates a sub-catchment identified as being under pressure as demonstrated by one or more indicators. No attempt has been made to rate the relative importance of these pressures: their implications are discussed within the Audit Report. The table should therefore be used as a guide only. The sub-catchments already determined by the SCA as priority sub-catchment for action are highlighted in the table (see also Chapter 1).

There are a number of sub-catchments that are under pressure from a large number of factors. They are the Kangaroo River (priority), Wingecarribee River (priority) and Wollondilly River (priority) sub-catchments. There are also a number of sub-catchments which are under less pressure than the above sub-catchments, but where there is still potential that the health of the ecosystem could be affected. These sub-catchments are Mulwaree River (priority), Upper Coxs River (priority), Nattai River, Upper Wollondilly River (priority) and Werriberri Creek (priority).

Table ES1 – Issues arising in each sub-catchment from the audit of available data for each indicator and issue in this Audit Report

Indicator number Indicator or issue

Bac

k &

Rou

nd

Mou

ntai

n C

reek

Blu

e M

ount

ains

Bor

o C

reek

Bra

idw

ood

Cre

ek

Bun

goni

a C

reek

Endr

ick

Cre

ek

Jerr

abat

tgul

la

Cre

ek

Kan

garo

o R

iver

*

Kow

mun

g R

iver

Lake

B

urra

gora

ng

Littl

e R

iver

Low

er C

oxs

Riv

er*

Mid

Cox

s Riv

er*

Mid

Sho

alha

ven

Riv

er

Mon

garlo

we

Riv

er

Mul

war

ee R

iver

*

Nat

tai R

iver

Ner

rimun

ga

Riv

er

O’H

ares

Cre

ek

Ree

dy C

reek

Upp

er C

oxs

Riv

er*

Upp

er N

epea

n R

iver

Upp

er

Shoa

lhav

en R

iver

Upp

er

Wol

lond

illy

Riv

er*

Wer

riber

ri C

reek

*

Win

geca

rrib

ee

Riv

er*

Wol

lond

illy

Riv

er*

Wor

onor

a R

iver

Phosphorus ● ● ● ● ● Nitrogen ● ● ● ● ● STP ● ●

2.1

Unsewered ● ● ● ● ● 2.2 Water quality at WFPs ● ● ● 2.3 Algal blooms ~ ● ~ ~ ~ ~ ● ~ ● ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ● ~ ~ ~ ● ~ 2.4 Pathogens ~ ~ ~ ~ ~ ~ ~ ● ~ ~ ~ ● ~ ~ ~ ~ ~ ~ ~ ● ~

Extraction licences ● ● ● ● ● 3.1 Farm dams ● ● ● ● ● ● ● ● ●

3.2 Groundwater bores ● ● ● ● ● Weirs ● ● ● 3.3 Transfers ●

Increasing urbanisation ● ● ● 4.1 Other developments ●

4.2 Sites of pollution or potential contamination ● ● ● ● ● ● ● ● ● ● ●

4.3 Soil erosion ● ● 4.4 Dryland salinity ● ● ●

5.1 Ecosystem water quality ~ ~ ~ ~ ● ~ ● ~ ~ ~ ~ ~ ~ ● 5.2 Macroinvertebrates ● ● ● ● ● ● ● ● ● ● ● ● ● ● ~ ● ● ● ● ● ● ● 5.3 Fish ● ● ● 5.4 Riparian vegetation ● ~ ● ● ~ ● ~ ● ~ ● ● ● ~ ● ● ● 5.5 Native vegetation ● ●

Notes: ~ No data available. ● Criteria for a blue dot are in Appendix A Table 1. * Determined by the SCA as a priority sub-catchment.

Recommendations

1 DEC, the SCA and the NRC give further consideration to integrating catchment and natural resource management audit processes and NSW State of the Environment reporting.

2 The SCA work with DNR and councils to establish a spatial information system to track and record the date, type and location of all on-ground works being undertaken or funded by Government for the purpose of water quality and ecosystem health management in the Catchment.

3 The SCA examine the potential for, and benefits of, integrating ecosystem water quality, macroinvertebrate, fish (when developed) and riparian vegetation condition monitoring programs.

Raw water quality

4 The SCA further develop L-THIA nutrient modelling for all sub-catchments to assist in prioritising nutrient reduction programs.

5 The SCA focus its programs for nutrient reduction from diffuse sources on the Wingecarribee River (priority), Wollondilly River (priority), and Mulwaree River (priority) sub-catchments, and encourage other organisations undertaking related programs to focus on these same sub-catchments where possible.

6 The SCA identify the cause of exceedence of the Bulk Water Supply Agreement for turbidity, pH and algae at water filtration plants.

7 The SCA identify the cause of the ‘high’ incidences of algal blooms in the Kangaroo River (priority), Wingecarribee River (priority), Mid Coxs River (priority) and Lake Burragorang sub-catchments and develop specific management strategies for each location.

8 The SCA investigate the source of Cryptosporidium oocysts at Gibbergunyah Creek and Propsect WFP and the source of Giardia cysts at Gibbergunyah Creek, Kedumba Creek, Wollondilly River at Jooriland and Murray’s Flat, and develop a management response at each location to reduce the incidence of Cryptosporidium and Giardia oocysts and cyst presence.

Managing water resources

9 The DNR undertake research into the impact of different levels of water extraction and harvesting of water in farm dams on flow regimes and ecosystem health within the Catchment, focussing on the sub-catchments most under pressure from water extraction and water harvesting.

10 The DNR use the results of research and improved knowledge about the impacts of water extraction and water harvesting in periodic reviews of Water Sharing Plans in the Catchment.

11 The DNR require groundwater extraction volume metering and reporting with a priority for implementation on licences in the Southern Highlands, Kangaroo River (priority), Werriberri Creek (priority) and Wingecarribee River (priority) sub-catchments.

12 The DNR give consideration to locating new monitoring bores in the Southern Highlands, Kangaroo River (priority), Werriberri Creek (priority) and Wingecarribee River (priority) sub-catchments.

13 The DNR develop a hydrological model that investigates the interaction between surface and groundwater systems and that can be used to manage surface and ground water extraction from the Catchment.

14 The DNR develop and implement systems for measuring and reporting of flow and flow variability for all sub-catchments to support the implementation of extraction rules and periodic review of the Water Sharing Plans.

15 The SCA implement measures recommended by the Wetlands and Woodlots for rock armoury and vegetative stabilisation in Doudles Folly Creek and Glenquarry Creek as an interim measure to reduce streambank erosion caused by bulk water transfers.

Land condition

16 The SCA and the Department of Planning prepare a detailed land use map at five year intervals. The resolution and categorisation should be sufficient so that change from the previous map can be determined.

17 The SCA identify high risk activities where there is no documented best practice benchmarks, and work with relevant agencies, industries and landholders to develop and implement recommended management practices.

18 The SCA develop pollution prevention or rehabilitation programs at sites identified as very high, high and medium risk to water quality, in consultation with relevant agencies, operators and landholders.

19 The DNR develop systems in consultation with the SCA for recording the location, nature and extent of actual cases of soil erosion and land salinity in the Catchment.

20 Programs addressing soil erosion and salinity in the Catchment target areas with identified risk, and integrate with other programs for riparian and vegetation management where possible.

Ecosystem health

21 The SCA review its water quality monitoring program to ensure that appropriate ecosystem water quality monitoring is undertaken in all sub-catchments.

22 The SCA review its macroinvertebrate monitoring program to ensure that monitoring is further integrated with water quality monitoring (i.e. the sites are monitored for both macroinvertebrates and water quality parameters).

23 The SCA consider follow-up monitoring at macroinvertebrate monitoring locations that have significantly impaired or severely impaired AusRivAS ratings.

24 The NSW DPI, in consultation with SCA, develop a fish community monitoring program for the Catchment to assist the management of aquatic ecosystem health.

25 The DNR, DEC and SCA jointly undertake vegetation condition mapping of areas outside the Special Areas.

Introduction 1

Chapter 1 Introduction

1.1 Terms of reference for the Audit The Sydney Water Catchment Management Act 1998 (the Act) requires that an audit of the state of the land of the Sydney Drinking Water Catchment area be undertaken every two years, and that a report on that audit be submitted to the Minister for the Environment. This is the fourth Audit Report with previous reports published in 2003 by DEC, and in 2001 and 1999 by CSIRO.

Section 42 of the Act requires that the Minister for the Environment nominate a person to conduct the audit, and that each subsequent audit be conducted by that nominated person. The Minister for the Environment nominated the Environment Protection Authority (EPA) to undertake the third catchment audit in 2003. This Audit Report was submitted to the Minister in November 2003. The EPA is now part of the Department of Environment and Conservation (DEC). DEC has therefore undertaken the 2005 audit of the Catchment using the same Terms of Reference provided by the Minister for the 2003 Audit, namely:

1. Audit and report on the catchment consistent with current methods used for the purpose of New South Wales’ State of the Environment reporting, focusing on the priority sub-catchments.

2. As part of the audit, consult with stakeholders within 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 Report is required to be submitted to the Minister by 30 November 2005. Section 39 of the Act requires that this Audit Report be laid before both Houses of Parliament within one month of 30 November 2005. The Audit Report will also be available on the DEC’s website, and a copy mailed to interested stakeholders.

The Sydney Drinking Water Catchment The hydrologic Catchment covers 16,000 square kilometres and includes the Special Areas around storages and the outer catchment areas which includes land uses such as urban, agriculture and industrial activity. The Catchment extends from north of Lithgow on the Coxs River to 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. For the purposes of this audit, the Catchment also includes the hydrologic catchment of the Prospect Reservoir. The Catchment consists of 28 sub-catchments. Map 1.1 shows the Catchment location, location of the main rivers and sub-catchment boundaries.

Priority sub-catchments The Terms of Reference require the audit to focus on the priority sub-catchments. The Sydney Catchment Authority (SCA) developed a methodology for identifying priority sub-catchments for preparing rectification action plans (RAPs). This methodology identified priority sub-catchments using an assessment of water quality, risk to SCA reservoir water quality, and stream health. The SCA has determined the priority sub-catchments to be:

• Lower Coxs River • Mid Coxs River • Mulwaree River • Upper Coxs River • Upper Wollondilly River

• Werriberri Creek • Wingecarribee River • Wollondilly River • Kangaroo River

Map 1.1 – Sydney Drinking Water Catchment

Audit of the Sydney Drinking Water Catchment 2005 2

The auditor considers this an appropriate approach to define the priority sub-catchments, although as evidenced by this audit, there are no data sets for some criteria in several sub-catchments to enable the complete application of this approach. However, in the absence of an alternative approach, the auditor has used the SCA nomination of priority sub-catchments to focus some aspects of the 2005 Audit process. The priority sub-catchments are the same as for the 2003 Audit, except for the addition of Kangaroo River sub-catchment which the 2003 Audit revealed had issues in relation to 8 audit indicators.

The 2005 Audit process examined all sub-catchments to assess change over the audit period. However, the audit specifically focused on priority sub-catchments by undertaking the majority of catchment inspections in these priority sub-catchments and by identifying which audit indicators are of concern in each of these priority sub-catchments.

1.2 Purpose of the Audit The purpose of the Audit is to provide information to all stakeholders about:

• the state of the Catchment in 2005 by reporting on indicators of pressures on and state of the catchment

• changes in the state of the Catchment over time by identifying trends in selected indicators where possible.

The information from the 2005 Audit report, and past audits, can be used to guide decisions of land managers and the community about management of the catchment areas.

1.3 Audit methodology The Terms of Reference for the 2005 Audit require the use of current methods used for New South Wales State of the Environment (SoE) reporting. The current method used for SoE reporting is the ‘pressure-state-response’ model. This model is an appropriate audit approach to identify:

• current pressures on, and the state of the Catchment • changes in pressures on, and the state of, the Catchment over the audit period • gaps in current responses to pressures and Catchment health.

The Audit Report identifies current actions or programs being undertaken in the Catchment in response to recommendations from the 2003 Audit Report and in relation to the findings of the 2005 Audit of Catchment indicators. The 2005 Audit also identifies where there are gaps in responses to pressures on, and state of the catchment. However, the 2005 Audit has not attempted to evaluate the response actions as other processes listed in Section 1.4 are more appropriate for assessing the effectiveness of these response actions. The effectiveness of the response actions will also be revealed by changes in the pressures on, and state of the catchment in subsequent catchment audits.

Selection of indicators The 2005 Audit has assessed the same 16 indictors used for the 2003 Audit process. These indicators are designed to provide an understanding of water quality and ecosystem health across the Catchment. The indicators are separated into the following four themes:

• raw water quality • water resource management • land condition • ecosystem health.

Table 1.1 lists the 16 indicators in these themes and specifies for each indicator whether it reports on pressure or state within the Catchment. Some components within indicators are unlikely to change substantially within the two year audit period, or have no additional data or new information available since the 2003 Audit. These longer term components of the indicators are essential in identifying changes over timeframes greater than two years and it is therefore suggested that they be retained for re-examination and assessment in future audits. Short term components of the audit indicators provide an assessment of recent

Introduction 3

changes to pressures on and state of the Catchment within the current audit period. Further explanations of the components within individual indicators are found in the relevant chapters of this report.

Table 1.1 – Indicators in each theme assessed by the 2005 Audit

Theme Indicator Nutrient load (pressure)

Raw water quality at water filtration plants (state)

Algal blooms (state)

Raw Water Quality

Pathogens (state)

Surface water extraction (pressure)

Groundwater extraction (pressure)

Managing Water Resources

Water for the environment (state)

Changes in land use (pressure)

Sites of pollution and potential contamination (pressure)

Soil erosion (state)

Land Condition

Dryland salinity (state)

Ecosystem water quality (state)

Macroinvertebrates (state)

Fish (state)

Riparian vegetation (state)

Ecosystem Health

Native vegetation (state)

The auditor acknowledges there are many alternative and additional indicators that could also be used to assess the pressures on, and the state of, the catchment. However, the 2005 Audit has assessed the same indicators as used for the 2003 Audit process because:

• it is consistent with the Review of the Catchment Audit Framework undertaken by the Sustainable Investment Research Institute (2003)

• it enables direct comparison with the 2003 Audit to identify trends • the indicators remain relevant in describing the pressures on, and the state of, the Catchment • there is either adequate data to make meaningful assessment across the Catchment, or baseline

information has, or is being, established • the indicators are likely to be readily understood by resource management organisations, land managers

and the general community.

Notwithstanding this, the auditor also acknowledges that the indicators can evolve over time to respond to new pressures, emerging information about Catchment condition and more robust and efficient methodologies for data collection. To enable a rational review of the indicators used in future audits there should also be a revision of the arrangements for undertaking the audit as follows:

i) the auditor should be appointed at the start of the audit period ii) the indicators should be determined by the auditor in consultation with stakeholders at the start of the

audit period iii) a memorandum of understanding, or other binding mechanism, should be developed by the auditor to

ensure relevant stakeholders collect, store, maintain and provide data and information for the audit period to the auditor at a prescribed time using specified methodologies.

Such an arrangement would improve the rigour of the audit process.

Audit of the Sydney Drinking Water Catchment 2005 4

Effect of drought on Audit indicators The auditor recognises there are likely to be significant effects of drought on several of the Catchment indicators reported on in this audit. While there are no specific data which assist in quantifying those effects in the Catchment during the 2005 audit period, the scientific literature documents many of those effects (e.g. Humphries and Baldwin, 2003; Lake, 2000). For example, drought tends to lead to improvements in the physico-chemical conditions of waterways (principally because of reduced runoff) except where a large proportion of the flow is from Sewage Treatment Plants. Conversely, drought tends to aid the formation of algal blooms because water is flushed out of the system more slowly. Rain leads to input of chemicals from the catchment, such as diffuse contribution of nutrients, and therefore during higher flow, water quality guidelines for physico-chemical parameters tend to be exceeded, and increased turbidity prevents the establishment of algal blooms.

The Catchment has been in drought for several years. It should be noted, therefore, that this audit presents something of a snapshot of the Catchment under drought conditions. In this situation, comparisons with indicators in previous audit periods can be difficult as the status of indicators can change because of prolonged drought rather than because of direct human induced pressures. Where relevant the audit points this out in commenting on the results of the indicator data analysis. The report refers, where necessary, to drought or low-flow conditions.

Conduct of the Audit The 2005 Audit examined information on the 16 indicators for the period 1 July 2003 to 30 June 2005, where updated information or data was available. The audit consisted of the following steps:

• scoping the project • identifying information needs and likely sources of that information relevant to each indicator • stakeholder consultation • inspecting some of the Catchment area, for observable pressures, state and responses • collecting and analysing available information and data relevant to each of the indicators • comparing findings with the 2003 Audit Report • reviewing responses to the recommendations of the 2003 Audit Report • identifying data, knowledge and response gaps • drafting final report and recommendations • consulting with selected stakeholders to ensure accuracy of final report.

Consultation The primary raw data and information sources for the 2005 Audit were the SCA and the Department of Natural Resources (formerly the Department of Infrastructure Planning and Natural Resources) because of the responsibilities of these agencies as resource and catchment managers. However, the auditor recognised the potential breadth of knowledge, information and data that may also be available on Catchment health from other sources. So, in addition to direct liaison with the SCA and the Department of Natural Resources (DNR), the 2005 Audit sought information from other stakeholders by:

• directly writing to 56 stakeholders, including SCA consultative committees, relevant government agencies, Catchment Management Authorities, industry associations and non-government organisations

• inviting submissions through Notices in the Sydney Morning Herald, Daily Telegraph and 21 regional or industry newspapers.

Twenty one responses were received, including 10 from State agencies, 5 from individuals, 2 from Catchment Management Authorities, 2 from utilities, one from the NSW Aboriginal Land Council and one from local government. The auditors would like to thank all parties that made submissions in this process. Individuals and organisations that provided a response or submission are listed in Appendix B.

Introduction 5

Common matters raised from the consultation process were broadly:

• Water Quality: urban stormwater and sewage management systems. Water quality issues are dealt with in Chapters 2 and 5.

• Water Resource Management: water use efficiency, environmental flows, farm dams, and alternative water sources. Water resource management issues are examined in Chapter 3.

• Land Condition: weed management, salinity, land rehabilitation, industry impacts and new development. Land condition matters are dealt with in Chapter 4.

• Ecosystem Health: ecological communities, vegetation, fish and fish passage. Ecosystem health issues are addressed in Chapter 5.

The Audit Report deals with matters raised in submissions where they are relevant to the Terms of Reference and the audit themes and indicators. Because of the scale of the Catchment, the 2005 Audit Report does not address localised issues raised in submissions except by way of several illustrative case studies, nor does the 2005 Audit Report address broader issues such as alternative water sources and climate change as these are outside the Terms of Reference to examine the state of the Catchment.

Catchment inspections The auditor undertook 11 on-site inspections in the Catchment on 12 and 26 October 2005. The auditor chose sites mostly located in priority sub-catchments and which reflected an array of observable pressures and response programs. The sites inspected and the issues assessed at each site are listed in Table 1.2. The auditor would like to thank the SCA staff that provided information at many locations on catchment management issues and response programs, and also operators that provided access to their sites and valuable insights into management approaches, challenges and successes.

Table 1.2 – Catchment inspections undertaken to observe pressures and responses

Date Site Sub-catchment Issue/Indicator Urban stormwater pond, Macintosh Street, The Oaks

Werriberri Creek Nutrient management

Wollondilly Washery, Burragorang Road, Nattai

Lake Burragorang Remediation of sites of potential pollution and contamination

Duddawarra Bridge, Coxs River Mid Coxs River Weed removal from riparian zone

Wallerawang Colliery, Castlereagh Highway, Lidsdale

Upper Coxs River Remediation of sites of potential pollution and contamination 12

Oct

ober

200

5

Lithgow Community Nursery Upper Coxs River Remediation of sites of potential pollution and contamination

Pacsons Quarries Pty Ltd, Boxvale Road, Welby

Nattai River Example of management of sites of potential pollution

Berrima Weir Wingecarribee River Obstruction of fish passage and effect on flow regime

Glenquarry Cut Upper Nepean River Bulk water transfers

SCA Groundwater Test Bore Upper Nepean River Groundwater extraction

Tallowa Dam Kangaroo River Surface water management and fish passageway

26 O

ctob

er 2

005

Wingecarribee Reservoir Wingecarribee River Surface water management

Independence of the Audit It is important that the audit process is undertaken in an objective, transparent and independent manner. This will enable community and land managers to have confidence in using the information and findings of the 2005 Audit, and to develop effective responses where necessary. The following mechanisms were established to ensure the independence of the 2005 Audit process:

• Mr Tony Wright, Deputy Chairman of the EPA Board was invited to review the Audit Report in November 2005 and to confirm the independence and integrity of the audit process. In particular he was invited to confirm that the audit had appropriately reviewed the EPA’s own roles and responsibilities as a regulator operating in the Catchment.

Audit of the Sydney Drinking Water Catchment 2005 6

• An internal DEC Steering Committee was established to guide the audit process and check on the transparency of the process.

• A project manager was appointed to DEC’s Policy and Science Division to manage the audit process, and to ensure that it was independent of response and regulatory programs and staff of DEC.

The final 2005 Audit Report was jointly endorsed by Mr Tony Wright and Dr Klaus Koop (Chair of the Steering Committee) and forwarded to the Minister for the Environment.

Data integrity and information accuracy The auditor identified existing data sets to assess indicators of pressures, and the state of, the Catchment, and requested these data from relevant organisations. The primary source of data was the SCA and the DNR. The auditor assessed the reliability of data by seeking explanations of anomalies or gaps in data sets provided and comparing data sets to independent sources such as previous audit reports and various Annual Reports.

Stakeholders that provided data to the audit were provided with a draft of the report to enable comment on the accuracy in the use of data. A list of these stakeholders is in Appendix C.

1.4 Relationship of Audit to other processes There are many audit and verification processes resulting from the legal and regulatory framework for Sydney’s bulk water supply. The following section outlines some of those processes, to provide the context in which this audit is undertaken.

Audit of SCA’s Operating Licence The SCA has an Operating Licence issued under the Sydney Water Catchment Management Act 1998. The current Operating Licence commenced on 1 January 2000 and remains in effect until 31 December 2005. The Operating Licence, inter alia:

• authorises SCA to undertake all functions conferred or imposed on it by the Sydney Water Catchment Management Act 1998

• enables and requires SCA to provide, construct, operate, manage and maintain bulk water supply systems • specifies performance and quality standards for the environment, catchment infrastructure work,

catchment management and protection, bulk water quality and customer service.

The Independent Pricing and Regulatory Tribunal (IPART) is responsible for auditing the SCA’s compliance with the Operating Licence on an annual basis. This IPART audit assesses the SCA’s performance against the benchmarks and requirements specified in the Operating Licence.

Assessment of SCA’s compliance with Water Management Licence The SCA holds a licence under the Water Act 1912 to enable it to extract surface water from the Catchment. This licence will be updated under the Water Management Act 2000 once a Water Sharing Plan has been agreed for the Catchment. The DNR administers this licence, and undertakes random site inspections and data verification processes to assess the veracity of dam release data and level of compliance of the SCA with its Water Management Licence.

Catchment Management Authorities and Catchment Action Plans The NSW Government established 13 Catchment Management Authorities (CMAs) across NSW in 2004. Three of the CMAs intersect with the Catchment, namely, the Hawkesbury–Nepean, Southern Rivers and Sydney Metropolitan CMAs.

The role of the CMAs is to ensure the protection and sustainable development of land, vegetation and water resources on a catchment basis. The CMAs are therefore key stakeholders for developing responses to pressures on catchment health and sustainable condition. To achieve this, CMAs are developing and implementing Catchment Action Plans, investment strategies and annual implementation plans. The strategies will aim to meet the standards and targets set by the NSW Natural Resources Commission (NRC).

Introduction 7

Natural Resources Commission (NRC) auditing The NRC has been established by the NSW Government to provide independent recommendations on standards and targets for natural resource management, recommend approval of CMA Catchment Action Plans and to audit the effectiveness of Catchment Action Plans in meeting the standards and targets. At this stage the NRC is considering a ten-year audit cycle, involving three audit phases within each ten year period (NRC, 2005). The audit stages would include an initial audit of the CMAs’ systems for meeting the NRC’s process-based quality standards for aspects such as community collaboration and for using best available information in decision making. The second audit phase would occur after about five years to audit the implementation of Catchment Action Plans by CMAs and their progress against medium-term catchment targets and their longer-term links to state-wide resource condition targets. The final phase after ten years would involve an audit of the outcomes and achievements of CMA Catchment Action Plans. The NRC may also undertake more frequent and issue-specific audits of CMAs on a risk basis. This audit process is expected to replace the two-year Statement of Intent (SoI) audit process formerly undertaken by the Healthy Rivers Commission.

Note that targets are not specified in this Audit Report, as was the case in the 2003 Audit Report, as this could potentially duplicate the NRC processes which have been established during this audit period.

1.5 Audit team Mr Tim Gilbert, Manager, Sydney Catchment Audit

Dr Sonia Claus, Senior Project Officer, Sydney Catchment Audit

Ms Beth Alexander, Environmental Technician, Sydney Catchment Audit

Ms Karen O’Neill, Environmental Technician, Sydney Catchment Audit

Mr Graham Turner, Remote Sensing GIS Specialist, Remote Sensing GIS Service

Mr Mark Roberts, Environmental Scientist, Remote Sensing GIS Service

1.6 Audit Steering Committee Dr Klaus Koop, Director Environment and Conservation Science (Chair)

Ms Liza Cassidy, Senior Public Affairs Officer

Mr Peter Marczan, Manager Technical Advisory Unit

1.7 Report on recommendations in the 2003 Audit The 2003 Audit made 25 recommendations. One recommendation related to the frequency of the audit process, five recommendations related to the theme of raw water supply, six to managing water resources, six to land condition and seven related to managing ecosystem health.

Relevant agencies have responded to many of the recommendations in the 2003 Audit Report by either directly initiating actions to address the recommendations, or undertaking actions which have indirectly addressed the intent of the recommendations. Notwithstanding this, the auditors note that some recommendations have not been adopted. The 2005 Audit Report repeats these outstanding recommendations where they remain relevant.

A summary of the level of response to the 2003 Audit Report recommendations is presented in Table 1.3, and more detail on specific actions and responses is provided below and in relevant chapters of this Audit Report.

The auditor notes the complexity of the institutional arrangements for environmental, catchment and natural resource management programs in the Catchment. Therefore, all relevant organisations need to be working co-operatively when implementing recommendations from the audit or undertaking other management programs to seek optimal efficiency and cost effectiveness of investment.

8 Audit of the Sydney D

rinking Water C

atchment 2005

Table 1.3 – Level of response to recommendations in 2003 Audit Report 2003 Audit

Theme Summary of 2003 Recommendations

(Recommendation No.) Status of response to recommendations in 2003 Audit Report

Aud

it pr

oces

s (1) Consideration be given to extending the frequency of the Catchment Audit to five years. Initiated

(2) SCA develops a model for estimating nutrient loads in each sub-catchment. Initiated (3) SCA identifies the causes of exceedences of Bulk Water Supply Agreement at Cascades and Greaves Creek water filtration plants. Completed (4) SCA identifies high incidences of algal blooms in storages. Initiated (5) SCA investigates the causes of pathogens detected at low levels in 2001 at the inlet to Prospect water filtration plant. Not undertaken

Min

imis

ing

cont

amin

atio

n of

raw

wat

er

supp

ly

(6) SCA investigates the source of pathogens at Gibbergunyah Creek. Initiated (7) Department of Infrastructure Planning and Natural Resources (DIPNR) expands research into impacts of surface water extraction. Not undertaken (8) DIPNR implements monitoring and reporting requirements to obtain reliable information on groundwater extraction. Initiated (9) DIPNR expands research to enable estimates of sustainable groundwater yield in the Catchment. Continuing (10) DIPNR and SCA expand research to better understand the interaction of surface and groundwater systems. Continuing (11) DIPNR implements mechanisms to enable reporting of environmental flows in relevant sub-catchments. Initiated

Man

agin

g w

ater

re

sour

ces

(12) DIPNR initiates the investigation of the impacts of bulk water transfers on ecosystem health. Completed (13) SCA prepares a detailed land use map. Initiated (14) Relevant agencies develop tools to indicate the effectiveness of management practices. Initiated (15) SCA sets timeframes for completing risk assessment and management processes for sites of pollution and potential contamination.

Initiated

(16) Programs for soil erosion target areas with high estimated soil erosion. Not determined (17) DIPNR in conjunction with SCA develops maps incorporating land use and land management for erosion risk management. Initiated Pr

otec

ting

and

impr

ovin

g la

nd

cond

ition

(18) DIPNR and SCA develop a methodology for identifying areas affected by salinity. Initiated (19) SCA adopts 300µS/cm as a conductivity trigger value for compliance monitoring in lakes and reservoirs. Completed (20) SCA reviews water quality monitoring programs to ensure monitoring in stressed areas of the Catchment. Not undertaken (21) A fish stock monitoring and management strategy be developed. Not undertaken (22) Riparian management programs be funded and integrated. Initiated (23) SCA develops a database monitoring all works affecting the quality of riparian vegetation and streambank stability. Initiated (24) SCA undertakes vegetation mapping in conjunction with DIPNR and DEC for the remaining areas of the Catchment. Completed M

aint

aini

ng a

nd

enha

ncin

g ec

osys

tem

he

alth

(25) SCA ensures riparian and native vegetation mapping is integrated and has full compatibility of data. Initiated

Introduction 9

Audit frequency The 2003 Audit Report recommended that the review of the Sydney Water Catchment Management Act 1998 consider extending the frequency of the audit period to five years, and that consideration be given to rationalising catchment audit processes within the natural resource management framework as they develop.

The auditor notes that the audit period of two years poses some difficulty in placing proper weight on the results of the analyses of Catchment data. On one hand this timeframe does not allow the audit results to be interpreted in the context of longer cycles such as climatic cycles. Thus differences in indicator data between successive audits can be properly interpreted only in the context of longer timeframes covering several audit periods. On the other hand, the two year cycle makes it unlikely that the effects of many of the management actions that might be undertaken in response to audit recommendations will be demonstrated within a two-year period. The auditor can only report where recommendations have been acted upon or not. It is worth noting that the NSW Natural Resources Commission has adopted significantly longer timeframes for successive audits of natural resource condition. Further consideration should be given to integrating this audit process with the natural resource management audit processes being established.

The Review of the Sydney Water Catchment Management Act 1998 was tabled in Parliament on 9 December 2004 by the Honourable Bob Debus, Minister for the Environment. This review considers that the Catchment audit process under Section 42 of the Act should be aligned with the NSW State of the Environment reporting process.

The auditor considers that there is potential to rationalise the Catchment audit, NRC audit and State of the Environment reporting processes by integrating them. To achieve this integration, further consideration by relevant agencies and stakeholders is required to:

i) establish a compatible and meaningful audit and reporting frequency for the Sydney Drinking Water Catchment

ii) broaden the scope of NRC audits to include an assessment of indicators of the state of the Catchment

iii) provide flexibility to NRC audit processes to examine catchment indicators beyond a single CMA boundary

iv) resolve the relationship between the NRC audits and the NSW State of the Environment reports.

Recommendation 1: DEC, the SCA and the NRC give further consideration to integrating catchment and natural resource management audit processes and NSW State of the Environment reporting.

Raw water quality The 2003 Audit Report recommended that the SCA develop a more sophisticated nutrient pollution model for each sub-catchment. The SCA has recently commenced trialling a Long-Term Hydrologic Impact Assessment (L-THIA) nutrient model, which uses more detailed inputs than the nutrient export model used to report on nutrients in the 2003 Audit Report. The L-THIA model uses new land use data, daily rainfall, soil permeability and event mean nutrient concentration for selected land use. The trialling of L-THIA modelling needs to be finalised.

The 2003 Audit Report also recommended that the SCA investigate the following specific water quality issues:

i) exceedence of the Bulk Water Supply Agreement (BWSA) for pH and algae at specified water filtration plants

ii) high incidences and long duration of algal blooms in its storages

iii) reasons for low levels of Cryptosporidium oocysts at the inlet to Prospect water filtration plant in late 2001

iv) the source of Cryptosporidium oocysts and Giardia cysts at Gibbergunyah Creek.

Progress on these recommendations has generally been positive.

Audit of the Sydney Drinking Water Catchment 2005 10

The SCA advises that it has assessed the exceedences of the BWSA with Sydney Water Corporation which concluded that the pH fluctuations and level of algae at the specified water filtration plants are related to natural processes resulting from local soil and other antecedent conditions. The BWSA has been amended in consultation with NSW Health and Sydney Water Corporation. The amendments were on public exhibition at the time of this audit process.

The SCA has completed a Cyanobacteria Risk Management Strategy since the 2003 Audit to address the algal blooms within storages. The Strategy includes short and medium-term measures to manage algal blooms and to maintain continuity of bulk water supply. It also includes long-term measures to protect good performing storages, and to rectify the catchments of storages that are currently afflicted by frequent or long duration algal blooms.

The SCA advises that there has been no further incidence of Cryptosporidium oocysts at the inlet to Prospect water filtration plant since the occurrence in 2001, reported in the 2003 Audit Report. In any case, Prospect Reservoir is a stand-by supply reservoir that is not generally in active use, although water quality monitoring is undertaken prior to any pumping for water supply.

The SCA has met with the operators of the Braemar Sewage Treatment Plant (STP) in relation to Cryptosporidium oocysts and Giardia cysts at Gibbergunyah Creek, and has determined that the ultra violet (UV) disinfection process, which should render the oocysts and cysts unviable, was not operating effectively. The SCA advises that the STP now appears to be operating satisfactorily. However, no follow-up monitoring of the STP is reported to have been undertaken to verify that the STP was the source of Cryptosporidium oocysts and Giardia cysts, and that the STP is now disinfecting adequately to ensure the oocysts and cysts are not viable.

Managing water resources The 2003 Audit Report recommendations on water resource management related to:

i) improving the understanding of the impacts of water extraction and farm dams on ecosystems and flow regimes to better guide resource allocation and management

ii) improving the reliability of information about groundwater extraction and expanding research to refine sustainable groundwater yield estimates

iii) improving the understanding of the interaction of groundwater and surface water systems

iv) implementing approaches to measure environmental flows in relevant sub-catchments

v) investigating the impact of bulk water transfers on ecosystem health.

Understanding the impact of water extraction on flow regimes and ecosystem health

The DNR advised the auditor that a generalised expansion of research into the impact of different levels of extraction on ecosystem health and flow regimes is inconsistent with its current priorities and available funding, although it has implemented a range of management responses to protect environmental flows in the Catchment. The management responses include:

• the current development of a Water Sharing Plan for the Sydney Region which will include requirements for environmental flow releases from major dams and cease-to-pump rules for water extraction to protect low flows in streams

• the implementation of the Hawkesbury–Nepean Water Extraction Monitoring Strategy requiring extraction volume monitoring for licensed water extractions. The Strategy has commenced, and implementation will be completed by 2007. This monitoring will provide more reliable information about the actual volumes of water extracted within the Catchment in future audits

• measures to manage farm dams across the State, including amendments to ’reasonable use’ provisions of the Water Management Act 2000, and proposed reforms to local planning instruments to enable control of farm dams in new rural-residential sub-divisions.

The DNR intends to periodically assess the Sydney Region Water Sharing Plan, guided by better information from these management responses, together with information from past and current research programs on the link between flows and river health.

Introduction 11

Improving information on groundwater extraction and sustainable groundwater yields

The DNR has included a condition in all groundwater extraction licences in the Catchment (except those for domestic or stock use) to install meters to measure the volume of groundwater extraction.

The DNR’s current groundwater monitoring bore network is limited to the Southern Highlands and Blue Mountains. However, the following developments have occurred since the 2003 Audit to improve understanding of groundwater or to respond to increased knowledge about groundwater:

• additional funding has been allocated for the installation of new monitoring bores in the Shoalhaven and Hawkesbury–Nepean systems

• estimates of sustainable yield have been refined for the Wingecarribee Shire, resulting in the DNR issuing an embargo in April 2004 on new groundwater access licences for commercial purposes in specified areas of the Southern Highlands

• development of an estimated sustainable yield for the Coxs River Catchment, to set access rules in this area.

The DNR is also currently preparing a Macro Groundwater Plan for porous rocks in NSW. This plan will include areas in the Catchment such as Sydney Basin sandstone. The plan will provide rules for groundwater extraction and management for a ten-year period from July 2006.

Improving understanding of groundwater and surface water systems

The DNR advises there are two current processes that may provide better information about the interaction between groundwater and surface water systems. Firstly, the DNR has a joint research project with the Australian Nuclear Science and Technology Organisation (ANSTO) and the SCA to date groundwater in the Southern Highlands and in the Nattai River sub-catchment. This will provide an improved understanding of the interaction between surface and groundwater.

Secondly, the SCA is investigating groundwater reserves in the Catchment as part of the Government’s Metropolitan Water Plan, to identify whether there are viable groundwater reserves to augment Sydney’s drinking water supply as a short-term relief measure during drought conditions. Should viable reserves be identified, the SCA will need to undertake more detailed environmental assessments prior to the development of permanent bore fields, such as assessments on the impacts on groundwater dependent ecosystems. Such investigations would improve the knowledge and understanding of the interaction between groundwater and surface water systems.

Measuring environmental flows

The DNR is continuing negotiations with the SCA and Delta Electricity to augment stream flow gauging networks, to assist in managing environmental release requirements. In addition, flow monitoring in relevant sub-catchments will be necessary to support a Water Sharing Plan and enable the enforcement of cease-to-pump rules. The DNR advises that such an arrangement already exists in the Kangaroo River where a Water Sharing Plan has been in place since July 2004.

Investigating the impact of bulk water transfers

The DNR required the SCA to commission an independent assessment of the impacts of the Upper Nepean bulk water transfers, as part of its Water Management Licence. The SCA also commissioned an assessment of the impact of bulk water transfers from the Shoalhaven system into Glenquarry Cut and Doudles Folly Creek in 2003. These independent assessments have been completed and are discussed in more detail in Chapter 3. Since the 2003 Audit, the Government has released a Metropolitan Water Plan (DIPNR, 2004), which identifies potential water savings by piping bulk water transfers along Glenquarry Creek, Wingecarribee River and Wollondilly River. Such a scheme would eliminate the impacts of the Shoalhaven bulk water transfers. The auditor understands that the Government is still considering the costs of this water saving measure.

Audit of the Sydney Drinking Water Catchment 2005 12

Protecting and improving land condition The 2003 Audit Report recommended that the SCA prepare a land use map at suitable resolution for program planning purposes such as nutrient export and erosion modelling. The SCA has engaged the DNR to prepare a new land use layer for the Catchment using satellite imagery, and this layer is expected to be completed by December 2005. The SCA is also currently finalising the land use types which will be used in the land use information layer, and will include a process to enable land use change to be tracked over time. Such analytical capability should enable more precise assessment of land use change in each sub-catchment by future catchment audits.

The 2003 Audit Report also recommended that tools to indicate the effectiveness of management practices to reduce water impacts by different land uses be developed to enable more sophisticated nutrient and erosion modelling. The auditor identified two programs that specifically seek to address this recommendation, namely:

• a collaborative program between the SCA and the University of NSW to examine risks, design and management of alternative on-site systems

• a recent contract let by the SCA to develop a set of best management practices for grazing activities. The SCA has developed a Water Quality Risk Management Framework (WQRMF). This framework identifies hazards and risks to bulk water quality and enables the SCA to focus management and on-ground activities to minimise these risks in the Catchment areas, storages and in its delivery systems. The SCA is also developing Rectification Action Plans (RAPs) under the Regional Environmental Plan to identify water quality risks in other priority locations. The WQRMF and the RAPs provide the SCA with greater capacity to prioritise its on-ground actions to address specific risks such as sites of pollution or contamination. The Healthy Catchments Program then provides the strategies and mechanisms for addressing the identified risks in the Catchment. The Healthy Catchments Program has strategies for sewage, riparian management, urban stormwater, rural lands, land management, catchment information and compliance. The WQRMF and RAPs will guide the SCA in prioritising where to apply Healthy Catchments Programs. For example, using the WQRMF, the SCA has now developed a compliance strategy that enables it to prioritise inspections of sites of potential contamination and pollution that may impact bulk water quality. Using this process the SCA has set specific timeframes for assessing individual higher risk sites as recommended by the 2003 Audit Report (see Chapter 4).

The 2003 Audit Report recommended that programs to address soil erosion be focused on locations with high estimated erosion rates, and that land degradation maps be prepared to include land use and land management to assist erosion risk management and future audit reporting. The SCA has advised that it is developing methods for estimating soil erosion rates in a collaborative project with the CSIRO. The DNR also advised that it has provided SCA with improved soil landscape information in 2003 that would enable refined erosion hazard mapping in the Catchment. However, the 2005 auditor was not able to verify whether soil erosion programs are targeting high erosion risk areas, as there is insufficient information about the specific locations in which soil erosion works are being undertaken within the Catchment (see Chapter 4).

The DNR has been mapping outbreaks of dryland salinity in the Catchment as part of a broader mapping project across eastern NSW, which addresses the intention of the 2003 Audit Report recommendation on salinity. The findings of salinity outbreaks in the Catchment are presented in Chapter 4 of this report.

Maintaining and enhancing ecosystem health The SCA has adopted 300µS/cm for compliance monitoring of conductivity of lakes and reservoirs in its Water Quality Monitoring program, as recommended in the 2003 Audit Report.

The SCA’s current water quality monitoring program is driven by raw bulk water supply considerations and is therefore largely focused in locations near or within bulk water storages. The 2003 Audit Report recommended that the water quality monitoring program be reviewed to include locations identified as being subject to environmental stress. The SCA advises that it has established an internal working group to assess proposals for additional water quality monitoring sites. Based on the information provided to the 2005 Audit, it appears that, while the internal working group serves a useful purpose of reviewing and adding value to new monitoring proposals, the SCA has not actively reviewed its monitoring program to respond to the 2003 Audit recommendation. More discussion on this matter is included in Chapter 5 of this Audit Report.

Introduction 13

No monitoring or management strategy has been developed for fish stocks in the Catchment, as recommended in the 2003 Audit Report. The SCA does not consider that the management of fish stocks should be one of its objectives, although it does recognise that fish could be monitored as one indicator of stream health. More discussion of this matter is included in Chapter 5 of this Audit Report.

The 2003 Audit Report recommends the funding and integration of Catchment-wide riparian programs. The SCA’s Healthy Catchments Program includes a Riparian Strategy to determine the condition of riparian zones and to develop remedial measures. The SCA is also integrating funding for some riparian works (and other on-ground actions) with the priorities of the Southern Rivers and Hawkesbury–Nepean CMAs through the CMA’s Catchment Protection Scheme. In relation to riparian vegetation mapping the DNR advises that it is developing a riparian mapping program that will enable the identification of priority areas for riparian works, and the SCA is also mapping riparian vegetation using satellite imagery and aerial photography to enable indexing of the condition of the vegetation. The SCA and the DNR may need to ensure these mapping processes are not a duplication of investment, or conversely that the data sets are compatible as recommended by the 2003 Audit Report.

The 2003 Audit Report recommended the mapping of vegetation in outer Catchment areas to complement the detailed vegetation mapping undertaken in the Special Areas. The DNR has commissioned vegetation mapping in approximately 95 percent of the outer Catchment area since 2003. This mapping used a combination of vegetation modelling, aerial photograph interpretation and vegetation surveys to assist in delineating vegetation communities at a scale of 1:100,000 (compared to a scale of 1:25,000 for vegetation mapping undertaken within the Special Areas of the Catchment). The Hawkesbury-Nepean CMA has funded the mapping of the remaining five percent of the Catchment area at a 1:25,000 scale, and this mapping is expected to be completed by December 2005. The SCA advise that the mapping in the outer Catchment is not at the same resolution as the Special Areas because of the significant expense of mapping at this scale, although it will continue to refine mapping of native vegetation over time.

General observations The auditor has observed that there has been significant work since the 2003 Audit in establishing mechanisms to identify risks in the Catchment. The auditor also notes that there are many positive on-ground works that seek to address water quality and ecosystem health pressures and to improve Catchment condition. However, there are currently inadequate information management systems to enable a comprehensive understanding of the relationship between the full range of on-ground actions and the locations of pressures and risks in the Catchment. This is noticed particularly within riparian and native vegetation works and erosion control. A spatial information management system could provide the means to track the type, time and location of past and current on-ground activities that are related to the management of water quality and ecosystem health in the Catchment. Such a system would:

• enable improved integration of on-ground works across program areas and between agencies to address multiple objectives simultaneously

• provide a basis for reviewing the effectiveness of individual works over time, particularly where a monitoring program is linked with the works

• provide a direct connection between risk management policy frameworks such as the WQRMF and actual on-ground works under programs such as the Healthy Catchments Program and Catchment Protection Scheme

• permit more targeted and cost effective planning of works programs.

The SCA already has a Grants Evaluation and Monitoring database for tracking on-ground SCA programs. The SCA should work with other catchment and resource management organisations such as the DNR and councils to expand tracking of on-ground works in the Catchment related to water quality and ecosystem health management.

Recommendation 2: The SCA work with the DNR and councils to establish a spatial information system to track and record the date, type and location of all on-ground works being undertaken or funded by Government for the purpose of water quality and ecosystem health management in the Catchment.

Audit of the Sydney Drinking Water Catchment 2005 14

Monitoring programs for ecosystem water quality, macroinvertebrates, fish (when developed) and riparian vegetation condition could be integrated. While many of these programs should be reviewed individually as recommended in relevant chapters of this Audit report, there should also be a general review to examine the potential for integrating these programs to: • increase the robustness of the interpretation of the data • guide targeted management responses • provide more confidence for investment in catchment management decisions • ultimately enable individual monitoring programs to be streamlined or reduced where issues are resolved

or better understood.

Recommendation 3: The SCA examine the potential for, and benefits of, integrating ecosystem water quality, macroinvertebrate, fish (when developed) and riparian vegetation condition monitoring programs.

Raw Water Quality 15

Chapter 2 Raw Water Quality

Key Points

Indicator Status of Indicator

2.1 Nutrient load Agriculture and sewage treatment plants (STPs) are major sources of nutrients in the Catchment.

The total nutrient contribution from STPs has decreased compared to the 2003 Audit period.

2.2 Raw water quality requirements for water filtration plants

Raw drinking water quality generally meets the requirements of Sydney Water Corporation and NSW Health. There was however, an increase in the exceedence of the Bulk Water Supply Agreement for turbidity, colour and pH compared to the 2003 Audit period.

2.3 Algal blooms The incidence of toxic and total cyanobacteria blooms decreased slightly from the 2003 Audit period.

There is continued high incidence of cyanobacteria blooms indicating high levels of nutrients in some parts of the Catchment.

2.4 Pathogens There is continued high incidences of Cryptosporidium and Giardia at Gibbergunyah Creek.

Raw water quality is an essential theme for an audit of a drinking water catchment as it assesses the end product of the catchment management approach to water supply. Raw water quality is a function of the inherent geological conditions and in-stream processes combined with land use, land and catchment management practices and climatic conditions such as drought. This Chapter examines:

i) nutrient loads, as pressures on raw water quality can result from both point and diffuse source nutrient loads in the Catchment

ii) state of raw water quality as measured by algal blooms and pathogen presence in the Catchment and reservoirs, and raw water quality data at the water filtration plants.

16 Audit of the Sydney Drinking Water Catchment 2005

Pressures in the Catchment Raw water in the Catchment is generally of good quality and meets most applicable guidelines. However, there are significant pressures on water quality in the Catchment from point and diffuse sources of pollution. Point sources of pollution include discharges from sewage treatment plants (STPs), and other licensed activities such as mining. Diffuse sources include urban stormwater and rural runoff. Pollution from both point and diffuse sources is driven by land use, intensity of use and management practice.

Population growth in urban areas increases stormwater runoff and puts pressure on wastewater management systems, often resulting in the need for upgraded infrastructure. Population growth in rural areas can result in increased on-site sewage treatment that, if not well managed, can add to the diffuse pollution loads. Population growth can also drive the intensification of land use, which can increase land clearing, runoff and ultimately increase risk of impact on the quality of the raw water supply.

The performance of local government and Sydney Water STPs in the Catchment is variable, with some operating over capacity and others approaching capacity. Pollution reduction and wastewater re-use programs at STPs have great potential to reduce the amount of pollution and nutrients reaching waterways in the Catchment. Improved urban stormwater management will also have a positive effect on water quality.

There are large areas of agriculturally productive land in the Catchment where much of the native vegetation has been removed. Runoff from agricultural land can carry large amounts of sediment and nutrients into rivers and creeks. The amount of material washed into waterways is increased in areas of bare soil or reduced riparian vegetation. Rural runoff can also contain pesticides, and pathogenic material from areas with livestock. The condition and role of native vegetation in protecting the water supply is dealt with in Chapter 5.

Pollution and contamination from industrial and commercial sites in the Catchment can also impact on raw water quality. These are dealt with in Chapter 4.

2.1 Nutrient load

Background

Small amounts of nutrients are required for plant growth. However, in large amounts, nutrients can cause excessive algal growth in waterways. Excessive algal growth can disturb natural ecosystem processes and affect the health of waterways.

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.

Point sources of nutrients include STP discharges and other industrial discharges. 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 large volumes of STP effluent may be prone to eutrophication expressed as algal blooms.

The relative nutrient contribution of different point and diffuse sources needs to be understood to guide response programs. Catchment modelling for nutrient loads can provide valuable information on potential hot spots. This audit examines:

i) nutrient load modelling to understand locations of high diffuse nutrient export

ii) sewage management as a primary indicator of point sources of nutrients in the Catchment.

Raw Water Quality 17

The SCA has been trialling more sophisticated L-THIA models for nutrient export potential, as recommended in the 2003 Audit report. However, data from these trials were only available late in the 2005 audit process, and the auditors consider there are several issues which need to be resolved. These issues include:

• the methodology used by the SCA does not appear to be consistent across all sub-catchments

• the rainfall data applied in most sub-catchments is from one location, potentially providing spurious results especially at the boundary of each sub-catchment.

This Audit Report therefore presents the same nutrient export data as used for the 2003 Audit. This 2003 data estimates annual nutrient loads for each sub-catchment based on extrapolating nutrient export rates for land-use types from other studies. The auditor acknowledges there are also limitations associated with the 2003 nutrient modelling approach, which reinforces the need to further develop and finalise the L-THIA modelling (see Recommendation 4) to better assist in prioritising nutrient reduction work.

The sewage management components examined for this audit are:

• Nitrogen and Phosphorus loads discharged from STPs in the Catchment

• STP non-compliance with Environment Protection Licence effluent quality and monitoring requirements

• Number of sewage overflows from sewerage systems and bypasses of STPs

• Equivalent population estimates for unsewered villages.

Findings

Figures 2.1 and 2.2 present estimates of annual phosphorus and nitrogen export potential due to human activity from each sub-catchment for 7 land-use categories (i.e. in excess of exports from natural land cover). Agriculture is estimated to be the largest source of phosphorus and nitrogen within the Catchment. STPs are also a significant contributor of phosphorus and nitrogen in the Wollondilly River (priority) and Upper Coxs River (priority) sub-catchments. The sub-catchments with the greatest export potential of phosphorus loads are the Wollondilly River (priority), Wingecarribee River (priority), Upper Coxs River (priority), Mulwaree River (priority) and Kangaroo River (priority) sub-catchments (Figure 2.1). The sub-catchments with the greatest export potential of nitrogen loads are Wollondilly River (priority), Mulwaree River (priority), Wingecarribee River (priority), Upper Wollondilly River (priority) and Reedy Creek sub-catchments (Figure 2.2).

The generation rates of phosphorus were greatest in agricultural areas particularly in the Reedy Creek and Mulwaree River (priority) sub-catchments (Map 2.1). The generation rates of nitrogen had similar hot spots to phosphorus, however there were also hot spots of nitrogen generation in urban areas (Map 2.2). In addition to the Reedy Creek and Mulwaree River (priority) sub-catchments, the Upper Wollondilly River (priority) and Wingecarribee River (priority) sub-catchments are important for nitrogen generation.

18 Audit of the Sydney Drinking Water Catchment 2005

Figure 2.1 – Export potential of phosphorus loads (kg/year) due to human activity for all sub-catchments. Values in parentheses is the export rate (kg/ha/year).

0 10000 20000 30000 40000 50000 60000

Woronora RiverLittle River

Upper Shoalhaven RiverEndrick River

Blue Mountains Werriberri Creek

Lower Coxs RiverLake Burragorang

Jerrabatagulla CreekMongarlowe River

Bungonia CreekMid Shoalhaven River

Nattai RiverBack & Round Mountain

Nerrimunga RiverUpper Nepean River

Boro CreekBraidwood Creek

Kowmung RiverMid Coxs River

Reedy CreekUpper Wollondilly River

Kangaroo RiverMulwaree River

Upper Coxs RiverWingecarribee River

Wollondilly River

Sub-

catc

hmen

t

Annual load (kg/year)

Agriculture (0.34)

Disturbed Lands (1.25)

Forestry (1.1)

Mining (1.25)

Roads (1.6)

STP

Urban (1.7)

Source: SCA 2003

Figure 2.2 – Export potential of nitrogen loads (kg/year) due to human activity for all sub-catchments. Values in parentheses is the export rate (kg/ha/year).

0 50000 100000 150000 200000 250000 300000 350000 400000

Woronora RiverLittle River

Blue Mountains Endrick River

Lower Coxs RiverUpper Shoalhaven

Werriberri CreekLake Burragorang

Mid Shoalhaven RiverNattai River

Jerrabatagulla CreekMongarlowe River

Kowmung RiverUpper Nepean River

Bungonia CreekBack & Round

Nerrimunga RiverBoro Creek

Braidwood CreekMid Coxs RiverKangaroo River

Upper Coxs RiverReedy Creek

Upper WollondillyWingecarribee River

Mulwaree RiverWollondilly River

Sub-

catc

hmen

t

Annual load (kg/year)

Agriculture (4.4)Disturbed Lands (12)Forestry (2.9)Mining (12)Roads (2.7)STPUrban (5.9)

Source: SCA 2003

Map 2.1 – Modelled annual phosphorus export (kg/ha/year) due to human activity for all sub-catchments in the Sydney Drinking Water Catchment

Map 2.2 – Modelled annual nitrogen export (kg/ha/year) due to human activity for all sub-catchments in the Sydney Drinking Water Catchment

Raw Water Quality 19

Sewage treatment plants (STPs)

There are currently 11 municipal STPs in the Catchment at Bowral, Lithgow, Moss Vale, Bundanoon, Goulburn, Warragamba, Berrima, Braidwood, Braemar, Wallerawang and Mount Victoria. Warragamba discharges treated effluent outside of the Catchment, however overflows from the reticulation system can occur within the Catchment. The effluent from the remainder of the STPs is discharged directly into waterways in the Catchment, except at the Goulburn STP where much of the effluent is reused in effluent irrigation systems (see Figure 2.3). The Mittagong STP was decommissioned in 2001 and replaced by the Braemar STP, although the discharge point remained unchanged.

There are also 12 small package STPs within the Catchment that are not licensed by the EPA1. There was no information available to indicate the effectiveness of the environmental management of these plants.

Figure 2.3 – Pivot irrigator for beneficial reuse of Goulburn sewage treatment plant effluent Source: SCA 2005

The STPs are operated by the relevant councils and Sydney Water. The EPA regulates the environmental performance of the STPs under the Protection of the Environment Operations Act 1997 (POEO Act). Bowral, Braemar, Lithgow, Moss Vale, Bundanoon, Goulburn and Warragamba STPs are required to collect data on nitrogen and phosphorus loads as part of the load based licensing scheme under the POEO Act. This data has been used to compare nitrogen and phosphorus loads discharged from STPs in the Catchment since 2000 (see Figures 2.4 and 2.5).

The total nitrogen load discharged to water by all STPs in the Catchment reduced by 52,000 kilograms over the 2005 Audit period compared to the 2003 Audit period, with Goulburn STP contributing to 96% of that reduction. Similarly, the total phosphorus load discharged by STPs in the Catchment decreased by 41,000 kg over the 2005 Audit period compared to the 2003 Audit period, with Goulburn accounting for 52% of that reduction. The large decrease in the nitrogen and phosphorus loads discharged to water from the Goulburn STP is primarily due to beneficial reuse on council-owned agricultural lands in the vicinity of the STP and a decline in effluent volumes. The decline in effluent volumes at Goulburn STP may be due to water restrictions and residents re-using an increasing proportion of grey water in response to those water restrictions.

The nitrogen loads discharged from each of the Lithgow, Moss Vale, Bundanoon, Goulburn and Warragamba STPs decreased in the 2005 Audit period compared to the 2003 Audit period (see Figure 2.4). The nitrogen load at the Bowral STP has continued to increase at an average rate of 10% per year for the past

1 Notwithstanding the establishment of the Department of Environment and Conservation (NSW), certain statutory functions and powers, including those of the Protection of the Environment Operations Act 1997, continue to be exercised in the name of the EPA, a statutory body created by the Protection of the Environment Administration Act 1991.

20 Audit of the Sydney Drinking Water Catchment 2005

three years (see Figure 2.4). The phosphorus loads from the Goulburn, Lithgow and Warragamba STPs decreased during the 2005 Audit period compared to the 2003 Audit period, and the phosphorus load from Braemar, Bundanoon and Moss Vale STPs remained at relatively constant levels (see Figure 2.5). The phosphorus load from Bowral STP increased in 2003–04 and decreased in 2004–05, but the total load over the 2005 Audit period was higher than for the 2003 Audit period (see Figure 2.5).

The Environment Protection Licences for STPs in the Catchment impose effluent concentration and load limits and effluent and system monitoring requirements. Table 2.1 summarises the limit and monitoring non-compliances of STPs in the Catchment over the 2005 Audit period. Bowral STP continues to have high incidences of non-compliance and Lithgow STP incidences of non-compliance have increased since the 2003 Audit period. All other STPs improved compliance with licence limit and monitoring requirements since the 2003 Audit period.

Raw Water Quality 21

Figure 2.4 – Load of nitrogen (kg/year) discharged from STPs, 2001 to 2005

0

10000

20000

30000

40000

Ber

rima

Bow

ral

Brae

mar

Bund

anoo

n

Gou

lbur

n

Lith

gow

Mos

s V

ale

War

raga

mba

STP

kg(N

)/yea

r

2000-01 2001-02 2002-03 2003-04 2004-05

Source: DEC 2005 Note: Goulburn STP effluent is irrigated and is not discharged to water. Nitrogen load for the Goulburn STP in 2000–01 was 76,535 (kg/year)

Figure 2.5 – Load of phosphorus (kg/year) discharged from STPs, 2001 to 2005

0

2000

4000

6000

8000

10000

Ber

rima

Bow

ral

Bra

emar

Bun

dano

on

Gou

lbur

n

Lith

gow

Mos

s V

ale

War

raga

mba

STP

kg(P

)/yea

r

2000-01 2001-02 2002-03 2003-04 2004-05

Source: DEC 2005 Note: Goulburn STP effluent is irrigated and is not discharged to water. Phosphorus load for the Goulburn STP in 2000–01 was 19,926 (kg/year) and 14,651 (kg/year) in 2001–02

76,535

14,65119,926

22 Audit of the Sydney Drinking Water Catchment 2005

Table 2.1 – Effluent and monitoring non-compliances of licensed STPs during the 2005 Audit period

STP PH Discharge BOD Load

Total P

Total N TSS Oil &

grease Faecal

coliforms Monitoring Sludge Storage

Berrima 2003–04 2004–05

2X 2X

X

Bowral 2003–04 2004–05

2X X

X

X 2X

X X

X

X

2X

X X

Braemar 2003–04 2004–05

9X

X

X

Braidwood 2003–04 2004–05

X

2X

4X 2X

X

Bundanoon 2003–04 2004–05

X

X

X

Goulburn 2003–04 2004–05

2X

X

Lithgow 2003–04 2004–05

X X

X

X

X

2X

X

X Moss Vale 2003–04 2004–05

X

X

Mt. Victoria 2003–04 2004–05

4X

Wallerawang 2003–04 2004–05

3X

5X

10X

8X

7X

Warragamba 2003–04 2004–05

X

X

Source: DEC 2005

There are 12 sites where biosolids are applied to land and 16 sites where effluent is irrigated in the Catchment. There was no data available to indicate the effectiveness of environmental management of these sites. The locations of point source discharges licensed under the POEO Act in the Catchment are indicated in Map 2.3.

Sewerage systems have designed overflow points to release sewage to the environment to prevent sewage overflows into houses and other properties where it may cause an immediate public health issue. In dry weather, sewer overflows occur due to:

• chokes, blockages or excess flow in a sewer pipe where the overflow is from a design overflow point

• due to pipe defects where sewage leaks to ground and surface waters.

Map 2.3 – Nutrient point sources in the Sydney Drinking Water Catchment

Raw Water Quality 23

In wet weather, sewer overflows occur because of excess flow in the sewage system caused by:

• infiltration of water to the system through defects in the system, and privately owned sewer pipes

• illegal stormwater connections to the sewer.

Sewer overflows are of particular concern as the discharge is raw sewage, while STP bypasses are of concern as the discharge can include partially treated sewage.

The total number of sewage system overflows from all STPs in the Catchment increased from 18 during the 2003 Audit period to 28 for the 2005 Audit period of which 21 occurred in 2003–04. Goulburn and Bowral STPs had the most sewer overflows in the 2005 Audit period, with 12 and 10 overflows respectively (see Table 2.2).

Sewage flows can also bypass the treatment plant processes when the flow rate exceeds the hydraulic design capacity of the treatment plant. The total STP bypasses increased from 5 in the 2003 Audit period to 12 in the 2005 Audit period, with 10 bypasses occurring in 2004–05. The most STP bypasses occurred at Mount Victoria STP (see Table 2.2).

Unsewered villages

A number of villages within the Catchment have no sewerage service and are served by on-site effluent management systems such as septic tanks (see Map 2.3). Unsewered villages have been identified as key sources of potential pollution threats to drinking water quality.

Since the 2003 Audit period, the villages of Belimba Park, The Oaks and Oakdale have been connected to the West Camden sewage treatment system. The largest remaining unsewered villages are Buxton in the Little River sub-catchment with an estimated equivalent population (EP) of 1,957 and Robertson in the Wingecarribee River (priority) sub-catchment with an EP of 1,507 (see Table 2.3). The unsewered villages at Kangaroo Valley and Medlow Bath have high peak season equivalent populations. Investigations are currently being undertaken to sewer Robertson, Kangaroo Valley, Medlow Bath and Taralga.

Equivalent population estimates for 2005 show that unsewered villages vary in population size from 111 to 1,957 (see Table 2.3). The towns of Goulburn, Marulan, Mount Victoria, Woodford and Blackheath are serviced by STPs, however there remain a significant number of residences that have on-site systems. The SCA also owns a number of unsewered houses within the Upper Nepean River sub-catchment at the Cordeaux, Cataract, Avon and Nepean Dams. The majority of these houses are now connected to new pump-out systems which are regularly maintained.

24 Audit of the Sydney D

rinking Water C

atchment 2005

Table 2.2 – Number of discharges of untreated sewage from licensed STPs from 2000 to 2005 2000–01 2001–02 2002–03 2003–04 2004–05

Licensed STP Bypass Overflow

within sewerage

system Bypass

Overflow within

sewerage system

Bypass Overflow

within sewerage

system Bypass

Overflow within

sewerage system

Bypass Overflow

within sewerage

system

Braemar 2 x tm

1 x md

1 x bsm 2 x ps 1 x ps

Berrima 1 x ps 1 x ps

Bowral

1 x w 2 x w 2 x w 1 x ps

2 x ps

1 x bm

3 x md

1

1 x f

1 x w

1 x ps

3 x md

Braidwood 2 x md 1 x ps

Bundanoon 1 x dsm

Goulburn

1 x ps

7 x md

1 x eia

11 x md 1 x ps

Mittagong 1 x d

1 x w

1 x ps

1 x ap

Moss Vale 1 x w 1 x md

Mt Victoria

1 x w

1 x d

4 x w

2 x d

Wallerawang 1 x w

Total 3 2 3 2 2 16 2 21 10 7

Key: w: wet; d: dry; ps: pumping station; tm: transfer main; ap: access point; md: manhole discharge; bsm: break in sewer maintenance; eia: effluent irrigation area; bm: broken main overflow; f: flooding overflow; dsm: discharge sewer maintenance

Source: SCA 2005

Raw Water Quality 25

Table 2.3 – Equivalent population (EP) estimates of unsewered villages in the Catchment

Sub-catchment Village EP estimate

2001

EP estimate

2003

EP estimate

2005

Bungonia Creek Tallong ND 108 114

Endrick River Nerriga ND ND ND

Kangaroo River Burrawang 235 268 301

Kangaroo River Exeter 369 423 477

Kangaroo River Fitzroy Falls ND ND ND

Kangaroo River Kangaroo Valley* 1320 1506 1692

Kangaroo River Penrose 169 189 210

Kangaroo River Wingello 264 303 342

Lake Burragorang Nattai ND ND ND

Lake Burragorang Yerranderie and Quigtown ND ND ND

Little River Balmoral 165 192 219

Little River Buxton 1509 1733 1957

Mid Coxs River Hartley ND ND ND

Mid Coxs River Medlow Bath* 750 886 1022

Mongarlowe River Mongarlowe ND ND ND

Mulwaree River Tarago ND 105 111

Upper Nepean River Kangaloon ND ND ND

Upper Nepean River Yerrinbool 927 1047 1167

Wingecarribee River Robertson 1191 1349 1507

Wingecarribee River Sutton Forest 218 249 280

Wollondilly River Taralga 382 424 466

Total 7499 8782 9864

Source: CH2MHILL 2001 and SCA 2005 Notes: ND – Not Determined, but significantly below 200 EP Tallong and Tarago were not included in the last audit, but population changes occurred in the villages from the

previous audit. Reported Tallong and Tarago Population Growth data is sourced from Mulwaree Shire Council Settlement Strategy

Report, November 2003 *Values quoted in table are peak summer loadings.

Implication

The total reduction in nutrient contribution from STPs over the 2005 Audit period has been a positive outcome. However, some individual STPs have increased nutrient contributions which need to be addressed through upgrades and improved performance.

Although there is no data to confirm this for the Catchment over the 2005 Audit period, it is likely that the STPs have a greater influence on ambient water quality in the current low flow conditions resulting from drought. Given this, it is important that every opportunity is taken to reduce nutrient contributions from STPs in the Catchment. Effluent reuse opportunities should therefore be increasingly explored as an option for nutrient reduction when STPs are being constructed, augmented or upgraded.

The Goulburn STP in the Wollondilly River (priority) sub-catchment and Bowral STP in the Wingecarribee (priority) sub-catchment are of concern in respect of sewer system overflows. The EPA has imposed a

26 Audit of the Sydney Drinking Water Catchment 2005

Pollution Reduction Program on all STP operators to assess sewer system overflow, and to identify priorities for minimising risk to the environment and public health from overflows.

A large number of unsewered villages are located in the Kangaroo River (priority) sub-catchment. The Little River, Mid Coxs River (priority), Upper Nepean River and Wingecarribee River (priority) sub-catchments each have an unsewered village with an EP greater than 1,000 (Table 2.3).

Based on the 2003 nutrient modelling for diffuse nutrient pollution, the sub-catchments with the greatest export potential of phosphorus loads were Wollondilly River (priority), Wingecarribee River (priority), Upper Coxs River (priority), Mulwaree River (priority) and Kangaroo River (priority) sub-catchments. The sub-catchments with the greatest export potential of nitrogen loads were Wollondilly River (priority), Mulwaree River (priority), Wingecarribee River (priority), Upper Wollondilly River (priority) and Reedy Creek sub-catchments.

These findings highlight that there are many potential point and diffuse sources of nutrients in the Catchment. Clearly a range of programs are necessary to continue nutrient reduction in the Catchment, across both point and diffuse sources and at strategic land-use planning levels and on-ground works level.

Point source nutrient reduction has traditionally been easier to implement, as programs can target responsible entity through well established legal and regulatory frameworks. While these point source nutrient reduction programs should continue, the focus also needs to be placed on diffuse source nutrient reduction programs. Diffuse source nutrient reduction programs should focus on high risk land uses in locations with high estimated nutrient export potential. The further development of the L-THIA nutrient modelling should provide greater confidence in the locations and land uses which are targeted by such diffuse source nutrient reduction programs.

At the on-ground level, reduction in nutrient export from diffuse sources can be achieved through good land use management practices as well as through specific riparian vegetation, erosion control and streambank stabilisation projects. Diffuse source nutrient control programs should therefore be integrated with programs for riparian management and erosion control to obtain multiple water quality, land management and ecosystem health benefits where possible. This requires significant co-ordination across organisations and landholders that are involved in funding and managing these types of programs. Relevant organisations therefore need to be collaborating to ensure programs are complementary and target high priority nutrient areas and locations.

There are a number of agencies and organisations with responsibilities for nutrient management. These include the SCA for management of raw water quality and councils through land use planning, urban stormwater management and STP operation. There are also several organisations that implement programs related to nutrient reduction such as the CMAs’ soil erosion programs. It is important that one organisation maintains an overview of the relationship between these programs and encourages collaboration between organisations involved in nutrient management to seek efficient integration of programs for nutrient reduction in the Catchment. The auditor considers that the SCA is well placed to fulfil this role because it has an overview of the whole Catchment and has a direct interest in the raw water quality outcomes that can be affected by high nutrient levels. Given this view, the SCA should:

• ensure its own nutrient reduction programs target areas of priority nutrient contribution where there is greatest scope for nutrient reduction by application of improved practice

• encourage other organisations to implement programs that can contribute to nutrient reduction in similar priority areas.

Recommendation 4: The SCA further develop L-THIA nutrient modelling for all sub-catchments to assist in prioritising nutrient reduction programs.

Raw Water Quality 27

Recommendation 5: The SCA focus its programs for nutrient reduction from diffuse sources on the Wingecarribee River (priority), Wollondilly River (priority) and Mulwaree River (priority) sub-catchments, and encourage other organisations undertaking related programs to focus on these same sub-catchments where possible.

Future directions

A better understanding of the magnitude and pattern of delivery of nutrient loadings is required to further optimise management strategies to reduce nutrient loads and mitigate impacts.

STPs need to be managed to protect water quality in the Catchment, including establishing clear strategies for upgrading and augmenting STPs and reticulation systems to accommodate anticipated growth. The strategies need to plan for a range of potential growth scenarios, include funding options and seek to minimise nutrient growth through treatment upgrades and effluent re-use opportunities.

Case Study – Bowral and Bundanoon STPs

Bowral STP has operated over its design capacity for several years. The planned upgrade of Bowral STP was originally due for completion in July 2001, and has been deferred on several occasions, with the upgraded STP due for commissioning in November 2005. The nutrient loads discharged from the STP have increased over this time. There have also been increased overflows and bypasses and a number of exceedences of effluent quality limits over the 2005 Audit period. Water quality in the Catchment has been at risk as a result of the delays in upgrading the Bowral STP.

Bundanoon STP, like several other STPs in the Catchment, is currently operating near its capacity. Wingecarribee Shire Council is addressing this situation by placing a moratorium on approvals to new subdivision and/or medium density applications from 1 August 2004 until the STP is augmented. Council is working with State agencies in planning an augmentation of Bundanoon STP by 2007. This type of approach will minimise the potential for water quality impacts from operation of the STP and its reticulation system.

28 Audit of the Sydney Drinking Water Catchment 2005

State of the Catchment

2.2 Raw water quality requirements for water filtration plants

Background

Water Filtration Plants (WFPs) in the Sydney drinking water system are operated by Sydney Water Corporation. WFPs are an important part of a multiple barrier approach to improve drinking water quality (SCA 2003a). These barriers include catchment management, storage management, water filtration, distribution, and integrated water quality management. The level of contaminants in raw water supplied to the WFPs is monitored by SCA to optimise raw water quality supplied and minimise treatment costs. Raw water in storages should not be expected 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.

Site-specific raw water quality guidelines for each WFP (Prospect, Warragamba, Orchard Hills, Macarthur, Nepean, Illawarra, Woronora, Cascade and Greaves Creek) are outlined in the SCA’s Operating Licence and the SCA’s Bulk Water Supply Agreement (BWSA) with Sydney Water Corporation (see Table 2.4). The raw water quality parameters examined in this audit are the level of compliance of raw water with the BWSA at the Sydney Water Corporation WFPs for:

• turbidity (NTU)

• colour (CU)

• manganese (mg/L)

• pH

• algae (ASU/mL)

These parameters were selected as they are important for the delivery of quality drinking water and 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.

Table 2.4 – Bulk Water Supply Agreement water quality guidelines at each Water Filtration Plant (WFP)

WFP Turbidity (NTU) Colour (CU)

Manganese (mg/L) pH Algae

(ASU/mL)

Cascade 15 60 0.25 6.0–7.4 1000

Greaves Creek 40 60 1.00 4.4–9.2 1000

Illawarra 10 48 0.37 6.15–7.2 5000

Kangaroo Valley 5 40 1.2 5.5–8.5 1000

Macarthur 60 40 0.35 5.72–7.65 500

Nepean 183 60 1.45 4.80–7.65 1000

Orchard Hills

Prospect

Warragamba

40 60 1.40 6.27–7.87 1000

Wingecarribee 5 40 1.2 5.5–8.5 1000

Woronora 11 70 0.07 5.06–7.54 5000

Source: SCA 2005 Note: All figures are maximum guideline limits, except for pH that is a range of guideline limits.

Raw Water Quality 29

Findings

The number of Sydney Water Corporation WFPs at which raw water quality exceeded the guidelines in the BWSA increased from the 2003 Audit period for turbidity and colour (see Figure 2.6). The number of Sydney Water WFPs at which raw water quality exceeded the guidelines in the BWSA from the 2003 Audit period remained unchanged for algae (Figure 2.6). The guidelines for manganese were not exceeded by water supplied to any Sydney Water Corporation WFP.

The exceedences of the BWSA values for pH increased at seven Sydney Water Corporation WFPs compared to the 2003 Audit period. Prospect WFP decreased from 19% of samples exceeding the BWSA for pH to no exceedences of pH requirements during the 2005 Audit period (see Table 2.5).

Figure 2.6 – Percentage of water filtration plants where raw water supplied exceeded BWSA guidelines for each parameter for the 2001, 2003 and 2005 audit periods

0

20

40

60

80

100

Turbidity Colour Manganese pH Algae

Parameters

% o

f WFP

s in

exc

eede

nce

of

BWSA

1999-2001 2001-2003 2003-2005

Source: SCA 2005

Table 2.5 – Percentage of samples collected in exceedence of the BWSA for each parameter at WFPs

Turbidity Colour Manganese pH * Algae WFP 2003 2005 2003 2005 2003 2005 2003 2005 2003 2005

Cascade 0 0 0 0 0 0 31 81 58 8

Greaves Creek 0 0 0 0 0 0 0 0 54 22

Illawarra 0 0 0 0 0 0 6 81 0 0

Kangaroo Valley ND 29 ND 7 ND 0 ND 0 ND 60

Macarthur 0 0 0 0 0 0 11 16 3 2

Nepean 0 0 0 0 0 0 3 14 4 0

Orchard Hills 0 0 0 0 0 0 0 4 0 0

Prospect 0 0 0 0 0 0 19 0 0 0

Warragamba 0 0 0 0 0 0 0 19 0 0

Wingecarribee ND 50 ND 0 ND 0 ND 0 ND 64

Woronora 0 0 0 0 0 0 2 8 0 0

Source: SCA 2005 Notes: Red indicates exceedence of the BWSA by > 75% of samples, orange 50–75% of samples and yellow 25–50% of

samples. * percentage of samples outside the guideline range ND: No data – Kangaroo Valley and Wingecarribee new plants since last audit

30 Audit of the Sydney Drinking Water Catchment 2005

Implication

The exceedences of the BWSA for algae may be due to decreased flow resulting from drought conditions, as in general the likelihood of algal blooms increases as flow decreases. The exceedences of the BWSA for pH may be due to the current drought because a greater proportion of the water in storages is likely to be derived from groundwater. However, it is important to identify the cause of the exceedences of the BWSA for turbidity, pH and algae in raw water supplied to WFPs to ensure there are no other human induced causes that should be managed.

Recommendation 6: The SCA identify the cause of exceedence of the Bulk Water Supply Agreement for turbidity, pH and algae at water filtration plants.

2.3 Algal blooms

Background

Algal blooms are an indicator of high nutrient loads, or eutrophication. Algae can reproduce rapidly and form a bloom under favourable environmental conditions, such as high nutrient levels, reduced flow and high light penetration. Algal blooms give rise to a number of problems in waterways and water storage, including changes in pH, reduction of light penetration and the smothering of habitat and deoxygenation of water. Lack of dissolved oxygen in water can result in the death of fish and other aquatic organisms.

Algal blooms reduce the environmental values of water by limiting the potential uses of water resources for recreation and stock purposes and increasing the cost of treatment for human consumption. Algal blooms can also cause tainting of drinking water and disruption of filters and other operations. Blue–green algae, or cyanobacteria, are of particular concern as some species produce toxins that may cause skin irritations, gastrointestinal disorders and in extreme cases of prolonged exposure can result in permanent organ damage or death (DEC, 2003b). If the toxicity of the bloom is significant, the water becomes unusable for either drinking or other direct contact. Even at low concentrations some blue–green algae can cause strong tastes and odours in treated water. Few freshwater cyanobacterial species release toxins throughout their life cycle. However, toxins, organic matter and nutrients are released into the water from the cell when cells begin to die, or cell walls are ruptured such as when passing through filtration devices at WFPs.

The National Health and Medical Research Council (NHMRC, 1996) drinking water guidelines identify three levels of algal presence:

• low (< 2,000 cells/mL)

• medium (2,000 to 15,000 cells/mL)

• high (> 15,000 cells/mL).

The NHMRC (1996) drinking water guideline identifies greater than 2,000 cells/mL (medium and high categories) as an algal bloom. These guidelines also identify this level (> 2,000 cells/mL) as requiring further action. Medium levels (2,000 to 15,000 cells/mL) indicate that the organisms may be in log growth phase so treatment at this stage will destroy and remove algal cells but not the toxins they produce.

While the NHMRC drinking water guidelines have been used for this audit to show comparison with the findings of the 2003 Audit report, it should be noted for context that there are algal benchmarks. For instance:

• in 1992 the NSW State Algal Coordinating Committee (SACC) specified that recreation on water bodies should not be permitted when total cyanobacterial counts exceed 15,000 cells/mL (high NHMRC category)

Raw Water Quality 31

• the SCA’s Cyanobacterial Response Plan states that stakeholders will be alerted when known toxigenic cyanobacterial counts exceed 5,000 cells/mL and water users (Sydney Water, Shoalhaven City Council and Wingecarribee Shire Council) and NSW Health should be notified if the cyanobacterial counts exceed 15,000 cells/mL (high NHMRC category).

The frequency of the SCA’s sampling varies from site to site. Sites are sampled either weekly, fortnightly or monthly. Some sites are sampled more regularly in summer and ad hoc samples are also collected if an algal bloom is detected.

This audit examines the incidences of total and toxic cyanobacterial blooms using the NHMRC (1996) categories.

Findings

The incidences of toxic cyanobacteria decreased slightly in the 2005 Audit period, compared to the 2003 Audit period (see Table 2.6). However, the incidences of toxic cyanobacteria which contained greater than 2,000 cells/mL increased from the 2003 Audit period (Map 2.4 and Figure 1 in Appendix E). Increases in the incidence of toxic cyanobacteria occurred at Bendeela Pondage (B*), Bendeela Picnic Area (J∗ ), Lake Nepean 100 m upstream of the dam wall (I*), Lake Yarrunga at Kangaroo River (N*), Lake Burragorang at Wollondiily Arm (W*) and Wingecarribee Lake at outlet (X*) (Map 2.4, Table 2.6 and Appendix E Figure 1). Lake Wingecarribee composite and Mid Lake (AM and AL*) and Lake Nepean (AK*) had a large number of incidences of toxic cyanobacteria but were not sampled in 2001 or 2003 Audit periods (Table 2.6 and Appendix E Figure 1).

The incidences of total cyanobacteria decreased slightly in the 2005 Audit period, compared to the 2003 Audit period (see Table 2.7 and Appendix E Figure 2). However, the incidences of total cyanobacteria which contained greater than 2,000 cells/mL increased from the 2003 Audit period (Figure 2 in Appendix E). Increases in the incidence of total cyanobacteria occurred at Lake Greaves at Dam wall (G*), Lake Lower Cascade (H*), Lake Yarrunga at Kangaroo and Yarrunga Junction (L*), Lake Yarrunga at Kangaroo Arm (O*), Lake Top Cascade (P*) and Lake Burragorang at Wollondilly arm (W*) (Table 2.7 and Appendix E Figure 2). Lake Nepean (AK*) had a large number of incidences of total cyanobacteria but was not sampled in the 2001 or 2003 Audit periods (Table 2.7 and Appendix E Figure 2).

The incidence of total cyanobacteria blooms for all sampling stations for the four years from June 2001 to June 2005 shows distinct seasonal fluctuations with lower algal counts and less incidences of both total and toxic cyanobacteria occurring in winter (see Figure 2.7).

Implication

While the overall incidence of cyanobacteria declined over the 2005 Audit period, the continued and increased incidences of toxic cyanobacteria with greater than 2,000 cells/mL at sampling locations in the Kangaroo River (priority) and Wingecarribee River (priority) sub-catchments are of concern. The continued and increased incidences of total cyanobacteria with greater than 2,000 cells/mL at sampling locations in the Kangaroo River (priority), Wingecarribee River (priority), Mid Coxs River (priority) and Lake Burragorang sub-catchments are also of concern.

Algal blooms are triggered in various ways depending on the nature of the waterway and antecedent conditions in the Catchment. Nutrient inputs from catchment sources are clearly important, but other factors, such as turbidity of the water, internal nutrient cycling (i.e. nutrients regenerated from sediments), temperature and stratification of the water are also important in triggering and maintaining algal blooms. The range of options for managing algal blooms includes disrupting stratification, application of algicide, reducing nutrient fluxes from sediments, clay capping of sediments and reducing nutrient inputs from the

∗ See Map 2.4 for locations of sampling sites and Appendix E Table 5 for explanation of codes.

32 Audit of the Sydney Drinking Water Catchment 2005

Catchment. The best options for managing the impact of algal blooms on water quality and ecosystem health in each location can be developed when the processes responsible for triggering and maintaining algal blooms in the ‘hot spots’ are identified and understood.

Recommendation 7: The SCA identify the cause of the ‘high’ incidences of algal blooms in the Kangaroo River (priority), Wingecarribee River (priority), Mid Coxs River (priority) and Lake Burragorang sub-catchments and develop specific management strategies for each location.

Figure 2.7 – Number of cells of total and toxic cyanobacteria from June 2001 – April 2005

0

1

10

100

1000

10000

100000

1000000

10000000

Jun-01 Jun-02 Jun-03 Jun-04 Jun-05

Time

Cya

noba

cter

ia (c

ells

/mL)

Total cells Toxic cells 500 (Low) 2000 (Medium) 15000 (High)

Source: SCA 2005 Note: 500 (Low), 2,000 (Medium) and 15,000 (High) represent the NHMRC (1996) drinking water guideline categories

Map 2.4 – Toxic cyanobacteria presence with >2,000 cells/mL for the 2001, 2003 and 2005 Audit periods in the Sydney Drinking Water Catchment

Raw

Water Q

uality 33

Table 2.6 – Percentage of samples containing toxic cyanobacteria in the Sydney Drinking Water Catchment for the 2001, 2003 and 2005 Audit periods 1999–2001 2001–2003 2003–2005

Code SCA code Station name

Number of

samples High Medium Low

Number of

samples High Medium Low

Number of

samples High Medium Low

A DAV7 Lake Avon at the Upper Avon Valve 3 0 0 0 43 0 0 0 44 0 0 0

B DBP1 Bendeela Pondage 81 0 0 6 134 0 3 19 108 0 9 27

C DCA1 Lake Cataract at Dam Wall 1 0 0 0 8 0 0 0 27 0 0 0

D DCO1 Lake Cordeaux at Dam Wall 1 0 0 0 6 0 0 0 28 0 0 0

E DFF Fitzroy Falls composite 59 0 3 20 138 1 32 48 79 0 24 39

F DFF6 Lake Fitzroy Falls at Midlake 15 0 0 27 34 3 38 24 26 0 27 27

G DGC1 Lake Greaves at Dam Wall 3 0 0 0 54 0 0 0 107 0 1 0

H DLC1 Lake Lower Cascade at 50m upstream 1 0 0 0 55 0 0 0 106 0 0 0

I DNE2 Lake Nepean at 300m upstream of Dam Wall 2 0 0 50 11 0 0 0 27 0 4 11

J DPAE Bendeela picnic area 48 0 4 10 85 0 4 9 81 4 7 9

K DTA1 Lake Yarrunga at 100m from Dam Wall 1 0 0 0 7 0 0 14 4 0 0 0

L DTA3 Lake Yarrunga at Kangaroo and Yarrunga Junction 5 0 0 20 9 0 0 11 7 0 0 0

M DTA5 Lake Yarrunga at Shoalhaven River 1 0 0 0 4 0 0 0 3 0 0 0

N DTA8 Lake Yarrunga at Kangaroo River, Bendeela PS 36 0 0 25 97 0 1 13 109 1 12 14

O DTA10 Lake Yarrunga at Kangaroo arm, Reed Island 6 0 0 0 18 0 0 6 21 0 0 24

P DTC1 Lake top Cascade at 100m upstream of Dam Wall 2 0 0 0 58 0 0 0 106 0 0 0

Q DWA2 Lake Burragorang at 500m upstream of Dam Wall 13 0 0 15 36 0 3 3 53 0 0 0

R DWA9 Lake Burragorang at 14km upstream of Dam Wall 1 100 0 0 9 0 0 22 1 0 0 0

S DWA12 Lake Burragorang at 9km upstream of Coxs River 0 NS NS NS 13 0 0 8 1 0 0 0

34 Audit of the Sydney D

rinking Water C

atchment 2005

Table 2.6 – Percentage of samples containing toxic cyanobacteria in the Sydney Drinking Water Catchment for the 2001, 2003 and 2005 Audit periods (Continued)

1999–2001 2001–2003 2003–2005

Code SCA code Station name

Number of

samples High Medium Low

Number of

samples High Medium Low

Number of

samples High Medium Low

T DWA19 Lake Burragorang at Kembula River arm 0 NS NS NS 24 0 0 4 5 0 0 0

U DWA21 Lake Burragorang at Coxs arm 37 km upstream of Dam Wall 1 0 0 0 18 0 6 11 6 0 0 0

V DWA27 Lake Burragorang at Wollondilly arm 23 km upstream of Dam Wall 1 0 0 0 13 0 8 0 1 0 0 0

W DWA39 Lake Burragorang at Wollondilly arm 40 km upstream of Dam Wall 5 0 0 0 34 0 0 0 39 0 5 5

X DWI1 Wingecarribee Lake at outlet 89 0 0 22 116 0 5 38 162 7 38 28

Y DWO1 Lake Woronora at Dam Wall 0 NS NS NS 14 0 0 0 27 0 0 0

Z HBP HBP1 and HBP2 taps 0 NS NS NS 44 0 0 11 71 0 0 0

AA HFF4 NPWS picnic shelter tap at Fitzroy Falls 0 NS NS NS 46 0 9 24 72 0 0 0

AB HOP6 Oberon pipeline, Leura 0 NS NS NS 42 0 0 0 80 0 0 5

AC HPR1 Upper Canal at Prospect WFP 0 NS NS NS 2 0 0 0 20 0 0 0

AD HUC1 Upper Canal at Broughtons Pass 1 0 0 0 16 0 0 0 60 0 0 0

AE HUC3 Upper Canal at Kenny Hill 0 NS NS NS 2 0 0 0 30 0 0 0

AF RPR1 Lake Prospect at Midlake 32 0 3 13 78 0 0 0 114 0 0 3

AG RPR3 Lake Prospect near RWPS 17 0 0 6 74 0 0 3 111 0 0 6

AM DWI Lake Wingecarribee composite 0 NS NS NS 0 NS NS NS 81 1 27 31

AL DWI3 Lake Wingecarribee at Mid Lake 9 0 0 0 0 NS NS NS 17 12 82 6

AK DNE7 Lake Nepean 0 NS NS NS 0 NS NS NS 10 0 10 20

Total 434 0.2 1 15 1342 0.2 6 14 1834 1 9 10

Source: SCA 2005 Notes: NS: Not sampled High – (> 15,000 cells/mL); Medium – (2,000 – 15,000 cells/mL); Low – (500 – 2,000 cells/mL) Incidences in the high and medium categories are highlighted in red See Appendix E Table 5 for details of all locations

Raw

Water Q

uality 35

Table 2.7 – Percentage of samples containing cyanobacteria in the Sydney Drinking Water Catchment for the 2001, 2003 and 2005 Audit periods 1999–2001 2001–2003 2003–2005

Code SCA code Station name

Number of

samples High Medium Low

Number of

samples High Medium Low

Number of

samples High Medium Low

A DAV7 Lake Avon at the Upper Avon Valve 23 0 44 35 56 14 66 18 44 0 75 23

B DBP1 Bendeela Pondage 219 70 26 3 121 68 23 6 108 51 38 10

C DCA1 Lake Cataract at Dam Wall 25 0 80 12 20 25 75 0 27 11 56 26

D DCO1 Lake Cordeaux at Dam Wall 29 7 45 38 17 24 41 18 28 32 32 32

E DFF Fitzroy Falls composite 89 97 3 0 98 91 9 0 79 80 20 0

F DFF6 Lake Fitzroy Falls at Midlake 29 100 0 0 26 92 8 0 26 69 31 0

G DGC1 Lake Greaves at Dam Wall 84 0 33 60 94 1 42 40 107 7 55 19

H DLC1 Lake Lower Cascade at 50m upstream 60 0 7 48 73 0 10 34 106 1 17 31

I DNE2 Lake Nepean at 300m upstream of Dam Wall 32 16 34 19 20 10 70 15 27 26 44 26

J DPAE Bendeela picnic area 142 7 23 31 78 50 17 10 81 15 17 15

K DTA1 Lake Yarrunga at 100m from Dam Wall 7 14 29 0 11 45 9 27 4 0 50 50

L DTA3 Lake Yarrunga at Kangaroo and Yarrunga Junction 19 26 42 26 12 42 25 8 7 0 86 14

M DTA5 Lake Yarrunga at Shoalhaven River 3 33 0 67 8 13 25 50 3 0 33 67

N DTA8 Lake Yarrunga at Kangaroo River, Bendeela PS 141 19 50 18 101 54 15 14 109 28 33 15

O DTA10 Lake Yarrunga at Kangaroo arm, Reed Island 22 23 77 0 19 47 21 26 21 29 67 5

P DTC1 Lake top Cascade at 100m upstream of Dam Wall 87 1 49 44 94 7 57 21 106 13 58 15

Q DWA2 Lake Burragorang at 500m upstream of Dam Wall 53 21 49 15 50 36 32 18 53 45 21 17

R DWA9 Lake Burragorang at 14km upstream of Dam Wall 3 33 33 0 11 73 27 0 1 100 0 0

S DWA12 Lake Burragorang at 9km upstream of Coxs River 3 67 0 33 12 67 33 0 1 100 0 0

36 Audit of the Sydney D

rinking Water C

atchment 2005

Table 2.7 – Percentage of samples containing cyanobacteria in the Sydney Drinking Water Catchment for the 2001, 2003 and 2005 Audit periods (Continued) 1999–2001 2001–2003 2003–2005

Code SCA code Station name

Number of

samples High Medium Low

Number of

samples High Medium Low

Number of

samples High Medium Low

T DWA19 Lake Burragorang at Kembula River arm 4 50 25 0 27 70 15 4 5 40 0 20

U DWA21 Lake Burragorang at Coxs arm 37 km upstream of Dam Wall 2 50 50 0 22 86 9 0 6 50 17 0

V DWA27 Lake Burragorang at Wollondilly arm 23 km upstream of Dam Wall 1 0 100 0 13 77 23 0 1 100 0 0

W DWA39 Lake Burragorang at Wollondilly arm 40 km upstream of Dam Wall 5 0 20 60 33 30 42 24 39 46 44 10

X DWI1 Wingecarribee Lake at outlet 119 92 8 0 116 98 2 0 162 94 6 0

Y DWO1 Lake Woronora at Dam Wall 22 0 36 23 29 0 55 28 27 7 52 22

Z HBP HBP1 and HBP2 taps 29 0 10 38 71 0 13 30 71 0 0 4

AA HFF4 NPWS picnic shelter tap at Fitzroy Falls 54 6 43 20 68 0 21 25 72 0 0 0

AB HOP6 Oberon pipeline, Leura 45 4 4 22 73 14 40 30 80 0 1 15

AC HPR1 Upper Canal at Prospect WFP 0 NS NS NS 22 0 41 32 20 0 0 30

AD HUC1 Upper Canal at Broughtons Pass 24 0 0 33 46 4 48 30 60 0 10 17

AE HUC3 Upper Canal at Kenny Hill 0 NS NS NS 23 0 35 48 30 0 10 27

AF RPR1 Lake Prospect at Midlake 87 64 24 8 100 63 20 12 114 33 28 11

AG RPR3 Lake Prospect near RWPS 27 96 4 0 97 66 20 9 111 35 24 13

AM DWI Lake Wingecarribee composite 0 NS NS NS 0 NS NS NS 81 93 7 0

AL DWI3 Lake Wingecarribee @ Mid Lake 0 NS NS NS 0 NS NS NS 17 100 0 0

AK DNE7 Lake Nepean 0 NS NS NS 0 NS NS NS 10 30 40 30

Total 1498 37 28 19 1661 41 27 17 1834 33 26 13

Source: SCA 2005 Notes: NS: Not sampled High – (> 15,000 cells/mL); Medium – (2,000 – 15,000 cells/mL); Low – (500 – 2,000 cells/mL) Incidences in 75–100% of samples red, 50–75% orange See Appendix E Table 5 for details of all locations

Raw Water Quality 37

2.4 Pathogens

Background

Cryptosporidium and Giardia are pathogenic micro-organisms which cause intestinal infections in humans. The micro-organisms are transmitted between humans by means of cysts which are found in excreted faecal material. Consumption of water containing cysts is the principal method of contracting the disease (Braidech and Karlin, 1985).

Sources of these micro-organisms include STPs, unsewered areas and native and domestic animals. There is potential for large amounts of pathogenic material, including Cryptosporidium and Giardia, to be mobilised during storm events and reach creeks, rivers and water storages.

This audit examines the incidence of DAPI (4’, 6-diamidino-2-phenylindole) positive Cryptosporidium oocysts and Giardia cysts in the Catchment during the 2005 Audit period and compares data from 2001, 2003 and 2005 audits. Identification of positive oocysts/cysts is undertaken using DAPI staining technique that identifies the presence of intact characteristic internal structures. In particular, the audit focuses on locations where Cryptosporidium oocysts or Giardia cysts were present in more than 5% of the samples collected at a location during the 2005 Audit period.

Findings

Cryptosporidium oocysts were detected during the 2005 Audit period in more than 5% of samples at Prospect WFP (AH**) and Gibbergunyah Creek at Mittagong (Braemar) STP discharge point (CD*).

The frequency of Cryptosporidium oocysts at Gibbergunyah Creek has significantly increased from 15% samples in the 2003 Audit period to 46% of samples for the 2005 Audit period. The incidence of Cryptosporidium oocysts decreased at the Upper Canal at the Prospect WFP (AC*) and Kedumba River at Maxwells Crossing (CC*) since the 2003 audit period to be present in less than 5% of samples during the 2005 Audit period (See Map 2.5 and Table 2.8).

The number of locations where Giardia cysts were present in more than 5% of samples increased from three in the 2003 Audit period to four in the 2005 Audit period. Giardia was detected in more than 5% of samples at Kedumba River at Maxwells Crossing (CC*), Gibbergunyah Creek at Mittagong STP (CD*), Wollondilly River at Jooriland (CL*) and Murray’s Flat (CI*) (See Map 2.5 and Table 2.9). The incidence of Giardia cysts at Gibbergunyah Creek (CD*) was detected in all samples, with medium or high levels in 73% of samples. At Kowmung River at Cedar Ford (CB*) however, percentages of Giardia detection decreased from 7% in 2003 Audit period to 3% in 2005 Audit period.

Implication

Gibbergunyah Creek appears to have a persistent source of Cryptosporidium oocysts, having had more than 5% of samples containing Cryptosporidium in the 2001, 2003 and 2005 Audit periods. The source of Cryptosporidium oocysts at the Gibbergunyah Creek and Prospect WFP and the source of Giardia cysts at Gibbergunyah Creek, Kedumba Creek, Wollondilly River at Jooriland and Murray’s Flat should be investigated.

* See Map 2.5 for locations of sampling sites and Appendix E Table 5 for explanation of codes.

38 Audit of the Sydney Drinking Water Catchment 2005

There is continued high and medium incidence of Cryptosporidium and Giardia at Gibbergunyah Creek near the location of the Braemar STP discharge point. While the SCA has identified that the UV disinfection process at the Braemar STP was not operating effectively, follow up investigation is necessary to confirm that the STP is the source of pathogens in Gibbergunyah Creek. The species of Cryptosporidium found in humans is Cryptosporidium parvum. Identification of the species of Cryptosporidium detected at Gibbergunyah Creek may assist follow-up investigations of the source of pathogens in Gibbergunyah Creek.

Recommendation 8: The SCA investigate the source of Cryptosporidium oocysts at Gibbergunyah Creek and Prospect WFP and the source of Giardia cysts at Gibbergunyah Creek, Kedumba Creek, Wollondilly River at Jooriland and Murray’s Flat, and develop a management response at each location to reduce the incidence of Cryptosporidium and Giardia oocysts and cyst presence.

Map 2.5 – Cryptosporidium and Giardia presence in > 5% of samples for the 2001, 2003 and 2005 Audit periods in the Sydney Drinking Water Catchment

Raw

Water Q

uality 39

Table 2.8 – Percentage of DAPI positive incidences of oocysts of Cryptosporidium in high, medium and low categories for the 2001, 2003 and 2005 Audit periods

Cryptosporidium 1999–2001

Cryptosporidium 2001–2003

Cryptosporidium 2003–2005 Code SCA

code Site Number

of samples

High Med Low

Number of

samples High Med Low

Number of

samples High Med Low

Q DWA2 Lake Burragorang at 500m upstream 1197 0 0 0 631 0 0 0.5 654 0 0 0.2 X DWI1 Wingecarribee Lake at outlet 92 0 0 0 121 0 0 1.7 110 0 0 0.9

AC HPR1 Upper Canal at Prospect WFP 15 0 0 6.7 11 0 0 9.1 54 0 0 3.7 AD HUC1 Upper Canal at Broughtons Pass 615 0 0 0.5 100 0 0 0 106 0 0 0 AF RPR1 Lake Prospect at Midlake 138 0 0 0 208 0 0 0 219 0 0 0.5 AG RPR3 Lake Prospect near RWPS 139 0 0 1.4 202 0 0 2.0 217 0 0 1.8

AH COMP1COMP3 Prospect WFP 670 0 0 0 604 0 0 2.7 2 0 0 50

AI COMP5 Illawarra System 264 0 0 0.4 92 0 0 0 91 0 0 0 AJ COMP6 Blue Mountains System 265 0 0 1.1 96 0 0 2.1 94 0 0 0 CA E083 Coxs River at Kelpie Point 40 0 0 0 31 0 0 0 31 0 0 0 CB E130 Kowmung River at Cedar Ford 39 0 0 2.6 28 0 0 0 33 0 0 3 CC E157 Kedumba River at Maxwells Crossing 35 0 0 2.9 30 0 0 6.7 37 0 0 2.7

CD E203 Gibbergunyah Creek at Mittagong STP 41 2.4 4.9 9.8 27 0 0 14.8 26 0 0 46.2

CE E206 Nattai River at Crags 0 NS NS NS 0 NS NS NS 1 0 0 0 CF E210 Nattai River at Smallwoods Crossing 30 0 0 0 22 0 0 0 19 0 0 0 CG E243 Little River at Fire Road 29 0 0 0 24 0 0 0 26 0 0 0 CI E409 Wollondilly River at Murray’s Flat 0 NS NS NS 0 NS NS NS 1 0 0 0 CL E488 Wollondilly River at Jooriland 42 0 0 2.4 31 0 0 0 29 0 0 0 CM E531 Werriberri Creek at Werombi 114 0 1 0.9 94 0 1.1 2.1 106 0 0 0.9

All samples 3765 0.03 0.08 0.5 2352 0 0.04 1.5 1856 0 0 1.4 Source: SCA 2005 Notes: NS: Not sampled High - (>1,000 oocysts per 100 L); Medium – (100–1,000 oocysts per 100 L); Low – (<100 oocysts per 100L) Incidences in 5–10% of samples are highlighted in orange and incidences in > 10% of samples are highlighted in red See Appendix E Table 5 for details of all locations

40 Audit of the Sydney D

rinking Water C

atchment 2005

Table 2.9 – Percentage of DAPI positive incidences of cysts of Giardia in high, medium and low categories for the 2001, 2003 and 2005 Audit periods Giardia 1999–2001 Giardia 2001–2003 Giardia 2003–2005

Code SCA code Site

Number of

samples High Med Low

Number of

samples High Med Low

Number of

samples High Med Low

Q DWA2 Lake Burragorang at 500m upstream 1197 0 0 0 631 0 0 0 654 0 0 0.3 X DWI1 Wingecarribee Lake at outlet 92 0 0 0 121 0 0 0.8 110 0 0 0

AC HPR1 Upper Canal at Prospect WFP 15 0 0 0 11 0 0 0 54 0 0 0 AD HUC1 Upper Canal at Broughtons Pass 615 0 0 0 100 0 0 0 106 0 0 0 AF RPR1 Lake Prospect at Midlake 138 0 0 0.7 208 0 0 0.5 219 0 0 0 AG RPR3 Lake Prospect near RWPS 139 0 0 2.2 202 0 0 0.5 217 0 0 0

AH COMP1COMP3 Prospect WFP 670 0 0 0.1 604 0 0 0.2 2 0 0 0

AI COMP5 Illawarra System 264 0 0 0 92 0 0 0 91 0 0 0 AJ COMP6 Blue Mountains System 265 0 0 0.4 96 0 0 0 94 0 0 0 CA E083 Coxs River at Kelpie Point 40 0 2.5 0 31 0 0 0 31 0 0 3.2 CB E130 Kowmung River at Cedar Ford 39 0 0 2.6 28 0 0 7.1 33 0 0 3.0

CC E157 Kedumba River at Maxwells Crossing 35 0 0 0 30 0 0 6.7 37 0 0 5.4

CD E203 Gibbergunyah Creek at Mittagong STP 41 9.8 29.3 12.2 27 18.5 37.0 18.5 26 19.2 53.8 23.1

CE E206 Nattai River at Crags 0 NS NS NS 0 NS NS NS 1 0 0 0 CF E210 Nattai River at Smallwoods Crossing 30 0 0 3.3 22 0 0 0 19 0 0 0 CG E243 Little River at Fire Road 29 0 0 0 24 0 0 0 26 0 0 0 CI E409 Wollondilly River at Murray’s Flat 0 NS NS NS 0 NS NS NS 1 0 0 100 CL E488 Wollondilly River at Jooriland 42 0 0 0 31 0 0 3.2 29 0 0 6.9 CM E531 Werriberri Creek at Werombi 114 0 0.9 1.8 94 0 0 0 106 0 0 0

All samples 3765 0.1 0.4 0.4 2352 0.21 0.43 0.6 1856 0.3 0.8 0.8 Source: SCA 2005 Notes: NS: Not sampled High - (>1,000 cycts per 100 L); Medium – (100–1,000 cysts per 100 L); Low – (<100 cysts per 100L) Incidences in 5–10% of samples are highlighted in orange and incidences in > 10% of samples are highlighted in red See Appendix E Table 5 for details of all locations

Raw Water Quality 41

Actions and Response

Response to issue

The primary responses to reducing contamination of the raw water supply are related to improving understanding of the relative contribution of nutrient sources and to reducing the amount of pollution entering waterways in the Catchment. Improving stream flow regimes, vegetation cover and riparian vegetation all contribute to reducing the impact of nutrients and pollution sources on raw water supply, and are dealt with in other sections of this report. This section covers the major actions to manage and reduce pollution discharge to the rivers and streams in the Catchment. These actions include:

• programs to understand nutrient sources

• programs to reduce nutrients from sewage management systems

• programs to reduce pollution from diffuse point sources (agricultural and urban runoff)

• programs to investigate exceedences of the Bulk Water Supply Agreement

• programs to investigate and reduce the incidence of algae blooms

• programs to investigate and reduce the incidence of pathogens.

General

The SCA has developed a Water Quality Risk Management Framework (2005) which combines the Pollution Source Risk Management Plan (GHD, 2000) and Bulk Raw Water Quality Management Plan (SCA, 2001) to provide a holistic framework to manage risks to water quality in the Catchment. The Water Quality Risk Management Framework (WQRMF) identifies hazards to bulk raw water quality and assesses the risk of events that cause these hazards. The framework also identifies and evaluates the controls to be used in dealing with the hazards throughout the SCA system.

Programs to understand nutrient sources

The SCA’s Collaborative Research Program includes a number of projects to evaluate and enhance tools for understanding nutrient contribution, including:

• A Nutrient Source Budgeting project with the University of Western Sydney which aims to evaluate and enhance tools for nutrient budget construction and prioritisation of land uses and abatement actions to reduce nutrient loadings

• Nutrient and Sediment Budgeting at Lake Burragorang with CSIRO

• Post Fire Water Quality with CSIRO to investigate the impact on water quality of post-wildfire erosion and nutrient release.

Programs to reduce nutrients from sewage management systems

Regulatory programs

The EPA regulates major point sources of water pollution using licences issued under the POEO Act. The licences include comprehensive requirements for pollution control, monitoring, and reporting. The EPA has imposed Pollution Reduction Programs (PRPs) on all regional (council) STP licences across the State requiring the licensee to submit a Sewer Overflow Investigations Report (PRP100) and An Incident Notification Protocol (PRP101) by June 2005. The Sewer Overflow Investigations Reports will identify overflows from the sewerage reticulation systems that pose a significant risk of harm to the environment or to public health and will identify management actions to reduce this risk. The Incident Notification Protocol will ensure incidents that may have public health and/or environmental consequences are reported to

42 Audit of the Sydney Drinking Water Catchment 2005

appropriate stakeholders in a timely manner. Other PRPs applying to licensed STP operators in the Catchment during the current audit period are listed in Table 2.10.

The installation and operation of on-site sewage systems is regulated by Local Government under a range of legislation including the Local Government Act 1993, the Environmental Planning and Assessment Act 1979 and the POEO Act. There are approximately 18,500 on-site sewage management systems in the Catchment. The primary regulatory program for on-site sewage management systems is the SepticSafe Program which was introduced in 1998. SepticSafe is a statewide partnership between the NSW Government and local councils to deliver improved management of on-site sewage management systems by providing education, support and supervision to landowners, to enable them to manage their systems so that they operate in accordance with health and environmental performance standards. The implementation of these strategies has included registration of the majority of on-site systems within the Catchment, inspection of systems, and the issuing of approvals to operate. Each council is required to develop an on-site sewage management strategy as part of the SepticSafe program to assist in addressing on-site systems on a risk basis.

Table 2.10 – STP PRPs during the 2005 Audit period Licensed

STP PRP Description

Bowral PRP1 STP upgrade which will reduce nutrients loads being discharged.

Braidwood PRP2

Install effluent irrigation/reuse at Braidwood Golf Course to meet environmental objectives.

Goulburn PRP3 PRP5 PRP6

Evaluate options for sustainable effluent management, and implement preferred option. Undertake a salt balance model for Kenmore irrigation area based on actual monitoring results. Investigate options to reduce total dissolved solids load in effluent.

Lithgow PRP1 PRP4

Upgrade STP such that quality of discharge meets BOD 10 mg/L and TSS 15 mg/L. Install and operate Nitrification/Denitrification reactor at STP and decommission redundant tertiary ponds.

Wallerawang PRP1 Upgrade the STP to meet specified effluent standards (except for NH3, TN and TP)

Source: DEC 2005

Other programs

• The SCA’s Healthy Catchments Program includes a Sewerage Strategy. The SCA’s Sewerage Strategy includes an Accelerated Sewerage Scheme which provides funding assistance to local councils to fast track sewer services and sewage treatment infrastructure upgrades in the Catchment. The Department of Energy, Utilities and Sustainability (DEUS) also provides funds to many of these projects. Some sewage system projects undertaken during the 2005 Audit period include:

o Goulburn STP – completion of an effluent transfer main from the Goulburn STP to agricultural land for beneficial reuse of effluent. Goulburn City Council has installed a new pivot and lateral irrigator at the effluent irrigation area on Murray’s Flat Road and is negotiating with landowners to acquire 334 hectares of irrigation land required to achieve sustainable effluent management.

o Wallerawang STP – a $3 million upgrade to improve treatment performance planned.

o Bowral STP – commencement of a $16.1 million upgrade of the Bowral STP will serve a population of up to 14 600 and improve treatment systems. This upgrade is expected to be completed in February 2006.

o Taralga – preliminary engineering and design of a sewerage system to serve the unsewered township of Taralga.

o Kangaroo Valley – undertaking of an options analysis for a sewerage system at Kangaroo Valley to serve 2,000 people.

o Investigations for upgrades of the Lithgow, Goulburn and Bundanoon STPs.

o Investigations to sewer the township of Robertson.

Raw Water Quality 43

• SCA also provided grants under the Healthy Catchments Program for Sewer Reticulation System Management, including funding Goulburn Mulwaree Council and Wingecarribee Shire Council to undertake sewer gauging and modelling to assist in overflow risk identification.

• Local councils have initiated projects to improve sewerage management under their jurisdiction. These include:

o Palerang Council to commission the NSW Department of Commerce to conduct a concept design study for the replacement of the Braidwood STP, sewage pumping stations and identified replacement pipework

o Lithgow City Council – Nitrification/denitrification and break point chlorination/dechlorination for the augmentation of the Lithgow STP, with funding from SCA

o Goulburn Mulwarree Council - $150,000 allocated to refurbish the degraded sewer lines under Goulburn’s central business district, with funding from SCA.

• The CRC for Water Quality and Treatment, SCA, University of NSW (UNSW) and Ecowise Environmental jointly undertook a risk assessment of on-site sewerage systems between June 2000 and December 2004.

Programs to reduce pollution from diffuse sources

Urban stormwater runoff

Stormwater management systems are generally owned by local government. Each local council has an urban stormwater management plan which prioritises works to reduce urban stormwater pollution. The NSW Government is assisting Councils to implement these plans by:

• passing the Local Government Amendment (Stormwater) Act 2005 on 12 October 2005. This legislation allows Councils to raise a stormwater management service charge for local and regional stormwater problems related to water quality, flooding, stormwater harvesting and asset management. The annual charge would be capped at $25 for a standard residential property and a pro-rata charge would apply to commercial or industrial premises. Councils will be required to consult with relevant CMAs on the actions to be funded by the proposed stormwater charge, to ensure that proposed projects of regional significance are consistent with the CMA’s Catchment Action Plan. Councils will also need to consult with relevant CMAs on the level of the charge.

• preparing guidelines on stormwater management

• funding local stormwater projects though the NSW Stormwater Trust.

Since 1998 the Stormwater Trust has provided approximately $6.6 million for 34 projects in the Catchment. Three projects were completed during the 2005 Audit period:

• Goulburn Mulwaree City Council – to develop a database template to be adapted and adopted by many small –to medium councils to ensure privately controlled stormwater devices are properly maintained and this maintenance is reported to the appropriate authorities.

• Blue Mountains City Council – to develop a Business Stormwater Program which targeted industry, particularly landscape suppliers, golf courses and nurseries to minimise their impact on urban stormwater and improve the water quality in the World Heritage Area.

• City of Lithgow Council – to undertake a broad education program with the community to minimise the amount of pollution entering the Coxs River.

In addition, the following projects have been undertaken during the 2005 Audit period:

• Wollondilly Shire Council is implementing The Oaks Stormwater Strategy, which has seen four gross pollutant traps and one subsurface wetland installed (Figure 2.8) to treat all stormwater that flows from The Oaks before it enters Werriberri Creek, with funding assistance from DEC and SCA. Council

44 Audit of the Sydney Drinking Water Catchment 2005

allocated $130,000 in 2003–04 for the installation of a second subsurface wetland. Regular maintenance of stormwater treatment devices includes removal of pollutants from gross pollutant traps that have contained large amounts of leaf litter and household rubbish and also removal of weeds from subsurface wetland. The Wollondilly District Stormwater Management Plan was reviewed by Council in 2004 and management action tables were updated to further improve quality of stormwater by installation of pollutant removal from stormwater runoff in Oakdale and The Oaks.

• Wingecarribee Shire Council designed and constructed a gross pollutant trap in Moss Vale Creek.

• Lithgow City council ran an Educate for Stormwater project and Stormwater media campaign during 2003–04.

Figure 2.8 – McIntosh Street subsurface wetland, The Oaks

The SCA also has a Stormwater Improvement Program which provides funding assistance to local government to improve stormwater management in the Catchment.

The SCA’s Healthy Catchments Program includes an Urban Stormwater Strategy. In 2003–04, as part of this strategy, the SCA collected data on urban stormwater infrastructure within the Catchment using its geographic information system. The SCA has then been able to commence the development of a software program to identify and rank risks to water quality from stormwater runoff.

Rural runoff

The following programs or actions have been initiated or undertaken during the 2005 Audit period, and assist in reducing pollution from rural runoff:

• The SCA’s Rural Lands Strategy under its Healthy Catchments Program aims to identify, prioritise and manage impacts within the Catchment caused by priority industry groups, diffuse sources, rural waste disposal and water erosion. For example, this strategy has included a Dairy Shed Waste Management Scheme that seeks to prevent dairy effluent from entering waterways in the Catchment by offering an 80% subsidy to dairy operators to implement effluent system plans. The scheme operates in the Shoalhaven, Metropolitan, Warragamba and Wingecarribee catchments. In 2003–04, four dairy farms

Raw Water Quality 45

joined the scheme, bringing the total number of participating farms to 15. The total volume of dairy effluent being recycled as a result of this scheme is about 134 kilolitres per day.

• The Catchment Protection Scheme which is co-ordinated by the CMAs and which receives funding from a range of sources including SCA and DNR. The Scheme provides advice and funding for on-ground works such as erosion management, rehabilitation and protection of riparian zones and effluent runoff.

• Various Best Practice Guidelines (BPGs) to maintain a strong, profitable agricultural sector at the same time as promoting environmentally sound practices, including:

o Best Practice Management Guidelines for Graziers on the Tablelands of NSW (HN CMA, NHT and NSW Agriculture 2004)

o Guidelines for the Development of Controlled Environment Horticulture (NSW DPI Agriculture 2005)

o NSW Meat Chicken Farming Guidelines (NSW Agriculture 2004).

Programs to investigate exceedences of the Bulk Water Supply Agreement

The SCA in collaboration with the Cooperative Research Centre for Water Quality and Treatment, the University of NSW and Sydney Water is investigating the generation, chemistry and transformation of iron and manganese in Lake Burragorang to understand those elements in raw water. The outcome of the research will enable the water treatment process to cope with high levels of dissolved iron and manganese in raw water which lead to discoloured water in the distribution system.

Programs to investigate and reduce the incidence of algae blooms

• The SCA has developed a Cyanobacteria Risk Management Plan (2005) which identifies the risks posed by cyanobacteria in SCA reservoirs and the risk management strategies required. The plan includes short, medium and long-term management options.

• The SCA’s water quality monitoring program includes specific assessments for the incidence and severity of cyanobacteria outbreaks. This program sets out the frequency and locations of compliance monitoring and the analytes to be measured at lakes within the SCA’s area of operation.

• Lithgow City Council has a Blue-Green Algae Program which is designed to assess blue-green algal levels in Lakes Lyall and Wallace major inflows.

• A fact sheet on ‘Managing blue-green algae in farms dams’ has been prepared by NSW DPI. This fact sheet provides information on the causes and ways to prevent algal blooms in farms dams. These preventive measures can also help in reducing algal blooms in natural waterways.

Programs to investigate and reduce the incidence of pathogens

• The SCA in collaboration with other research organisations has initiated the following research into pathogens:

o Pathogen Budget – A research project on the development of a pathogen budget model for the Wingecarribee sub-catchment. The University of NSW and SCA are also developing a pathogen budget to prioritise land uses and rectification actions to reduce public health risks from pathogens.

o Validation of model performance – investigates water quality issues, such as pathogen contamination, during floods and nutrient input from long-term catchment degradation.

o Limnological study of Lake Burragorang and Prospect Reservoir – final report received and currently being reviewed by SCA. SCA staff trained in the use of the model.

o Investigation options for providing disinfection of the Upper Canal Water and upgrading bio-monitors on the Upper Canal.

46 Audit of the Sydney Drinking Water Catchment 2005

o Molecular methods to trace faecal bacteria and bacteriophages in the catchment with the University of NSW.

o Molecular methods to trace faecal viruses in the catchment with the University of NSW.

o Native animals as potential sources of human pathogens in SCA catchments with Macquarie University.

o Prevalence of Cryptosporidium oocysts and anti-Cryptosporidium antibodies in animals in SCA catchments with Macquarie University.

o Cryptosporidium in the Warragamba catchment – genotypes and cell culture infectivity with Macquarie University.

o Links between microbial and physico-chemical parameters – Continuation of a research project on Fate and Transport of Surface Water Pathogens in Watersheds to assist in predicting concentrations of Cryptosporidium and Giardia in water at various locations within and at the bottom of sub-catchments.

o Comparative Trial of Cryptosporidium parvum Genotyping Methods – this project evaluated available molecular tools for tracing and tracking Cryptosporidium parvum isolates capable of causing infection.

o Hydrodynamic Distribution of Pathogens in Lakes and Reservoirs – this project was to develop, test and verify optimum and cost-effective sampling strategies for detecting pathogens in reservoirs.

• The SCA has reviewed its pathogen response protocols and investigation mechanisms to ensure all detections and subsequent investigations are fully completed, documented and reported to stakeholders.

• The SCA has undertaken intensive monitoring for Cryptosporidium and Giardia in the raw water supplied to the prospect WFP based on a public health risk in December 2004. Based on advice from an expert panel, future monitoring for Cryptosporidium and Giardia will be a combination of a risk based approach and targeted monitoring of source water to provide early warning.

• The SCA has also responded to the 2003 Audit Report recommendation to investigate sources of pathogens in Gibbergunyah Creek, as outlined in Chapter 1.

• The SCA’s Healthy Catchments Program (HCP) Riparian Strategy has a specific aim to reduce pathogen movement into gullies, streams, creeks and rivers.

Gaps in the response

The actions and responses for management of raw water supply are extensive. There have clearly been significant actions over the past few years to improve the understanding of risks to raw water quality and to establish frameworks to enable more targeted management responses in the future. On-ground responses to reduce risks to bulk water quality can now be implemented with greater confidence, guided by tools such as the Water Quality Risk Management Framework, Cyanobacteria Risk Management Plan, research from the SCA’s collaboration program and the recommendations from this audit.

Managing Water Resources 47

Chapter 3 Managing Water Resources

Key Points

Indicator Status of Indicator

3.1 Surface water extraction The auditor is unable to determine change from the 2003 Audit period due to differences in data format and accuracy.

There is little information available about actual volumes of water extraction and harvesting and its effect on the health of the Catchment.

3.2 Groundwater extraction There is little information available about actual volumes of groundwater extraction and its effect on the health of the Catchment.

An increase in groundwater extraction licences is likely to have increased the pressure on Catchment condition.

Groundwater levels in the Southern Highlands have decreased since 1999.

3.3 Water for the environment

There has been little change in total water volumes released from storages for environmental and riparian purposes since the 2003 Audit period.

The SCA complied with environmental release requirements of its Water Management Licence 99.7 to 99.9% of the time between 2001 and 2005.

The transfer of bulk water may be affecting the health of waterways within the Catchment.

Surface water and groundwater resources need to be sustainably shared between water dependent ecosystems and human uses such as drinking water and agriculture to ensure the continued availability of good quality water. This audit examines surface and groundwater extraction within the Catchment, and the effects of extraction on environmental flows, environmental flow releases and bulk water transfers.

Audit of the Sydney Drinking Water Catchment 2005 48

Pressures in the Catchment 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 affects in-stream ecosystem processes.

The major impacts of surface water extraction, and the 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, e.g. the flooding of riparian zones • changes in the duration and timing of flow events • creation of large, standing water bodies which are ideal for algal blooms • degraded water quality (Chapters 2 and 5) • loss of habitat connectivity, including physically blocking fish passage (Chapter 5) • change in water temperatures (Chapter 5).

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 reducing base flow in surface streams.

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 (Bennett et al. 2002). The volume, seasonality, velocity and rate of rise and fall of a flow can all affect waterway health (Bennett et al. 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.

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 raw water. These bulk water transfers can place significant stress on the geomorphology of rivers and streams and affect aquatic ecosystem habitats. The physical process of erosion and the rapid and extreme change in flow volume can also affect the riparian ecosystem.

3.1 Surface water extraction

Background

The allocation of water is very important in Australia to deal with rainfall and stream flow variability. The harvesting of surface water through farm dams or from direct extraction from waterways must be managed so there is adequate water at all times to supply human uses and to maintain healthy ecosystems. The sustainable management of surface water resources therefore requires knowledge of the rate of replenishment and flow, the amount of surface water that is extracted from streams or collected in dams, and the ecological impacts of different levels of extraction within the Catchment.

Approximately 530 gigalitres per year (or about 72 percent of total surface water use) is extracted from the Catchment for urban water supply. A total of approximately 115 gigalitres per year is used for irrigation purposes both in the Catchment and below storages in the broader Hawkesbury–Nepean catchment, which accounts for about 16 percent of total surface water use from the Catchment. Between about 80 and 90 gigalitres per year (or about 12 percent of total surface water use in the Catchment) is released from the Catchment storages specifically for environmental purposes.

Although the extraction of surface water for uses other than urban water supply are relatively modest in the overall catchment water balance, all surface water extraction is important to local stream flow and ecosystem health because of the location and timing of extraction. Water retained and extracted from the SCA’s storages primarily impacts on the natural flows of the river systems below the dams. This will be addressed

Managing Water Resources 49

through Water Sharing Plans outlined in the Actions and Response section of this Chapter. However, this audit primarily focuses on the extraction and harvesting of surface water within the Catchment itself.

To extract water from rivers and streams beyond ‘basic’ land holder rights, a water access licence must be obtained from the DNR (formally DIPNR) under the Water Management Act 2000 (or under the Water Act 1912). These licences detail the purpose of extraction and the maximum annual extraction volume that is permitted under the water access licence. The aggregate annual maximum volumes that are permitted by these licences to be extracted from each sub-catchment is summarised in Figure 3.11.

From 1998 a landholder’s right to harvest the runoff in a dam without needing a licence, registration, fees or metering is limited to 10% of the average regional rainfall runoff from the property. This is referred to as the ‘harvestable right’. The harvestable right enables the retention of runoff in farm dams. Farm dams larger than the harvestable right need to be licensed by DNR under the Water Management Act 2000. The Act 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.

For surface water extraction, this audit examines the:

• maximum permissible annual volume of surface water that can be extracted under water access licences in the Catchment

• number and location of farm dams greater than 50 metres in diameter.

Findings

Surface water extraction

The water extraction volumes for the 2005 Audit period are reported in sub-catchments, rather than in river systems as used for the 2003 Audit Report. Consequently, there is no comparison made between the 2005 Audit findings on surface water extraction data and those presented in the 2003 Audit Report.

Irrigation (17,842 ML/annum) and town water supply (17,719 ML/annum) are permitted to extract large water volumes in the Catchment under water access licence arrangements. Delta Electricity is also a major water user extracting over 20,000 ML in 2003/04 from the Upper Coxs River (priority) sub-catchment for the operation of Mount Piper and Wallerawang power stations (Delta Electricity 2004). Delta Electricity is also required to make environmental flow releases under its water access licence. Other purposes for surface water access licences include stock, railway, pisciculture, domestic, industry, mining, farming, and high and low security recreation (see Appendix E Table 3).

The Upper Wollondilly River (priority) sub-catchment has the highest aggregate water volume permitted to be extracted under water access licences, accounting for over 30% of the total volume permitted to be extracted from the whole Catchment. This large permissible volume is due to extractions for town water supply (Figure 3.1). The Wollondilly River (priority) sub-catchment has the highest volume of water permitted to be extracted for irrigation purposes.

1 The actual volume extracted under each licence is not currently monitored. As outlined in Chapter 1, the DNR is implementing the Hawkesbury–Nepean Water Extraction Monitoring Strategy requiring extraction volume monitoring for licensed water extractions. The Strategy is expected to be implemented by 2007. Records of actual surface water extraction volumes should be able to be reported in Catchment audits from that time.

Audit of the Sydney Drinking Water Catchment 2005 50

Figure 3.1 – Maximum annual volumes (megalitres) permitted to be extracted by water access licences

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Source: DIPNR 2005

Farm dams

Farm dams (Figure 3.2) may indicate pressure on water quantity for local ecosystem health within the Catchment as they intercept a significant proportion of surface flow from low and medium intensity rainfall events. Map 3.1 shows the location of all farm dams greater than 50 metres in diameter using data from Landsat imagery. There are 18,319 farm dams over 50 metres in diameter currently recorded by the SCA in the Catchment. There are over 3,500 of these farm dams located in the Wollondilly River (priority) sub-catchment, and over 2,000 farm dams in each of the Upper Wollondilly River (priority), Mulwaree River (priority) and Wingecarribee River (priority) sub-catchments (see Map 3.1). There are over 1,000 farm dams located in each of the Nerrimunga Creek and Reedy Creek sub-catchments. The Kangaroo River (priority), Bungonia Creek and Braidwood Creek sub-catchments also have large numbers of farm dams (between 700 and 900). The sub-catchments that drain to Lake Burragorang have higher numbers of farm dams than the sub-catchments flowing into other storages (Map 3.1).

The auditor became aware when checking the data on farm dams that the data sets used to present farm data in previous audits was not complete. The 2005 Audit Report does not therefore make a direct comparison of the number of farm dams with the 2003 Audit Report, although it is likely the number has increased in response to drought and because of rural residential development.

Map 3.1 – Farm dam locations in the Sydney Drinking Water Catchment

Managing Water Resources 51

Figure 3.2 – Farm dam in the Kangaroo River (priority) sub-catchment, October 2005

Implication

Current data do not allow a solid assessment to be made about the extent to which surface water extraction or water harvesting in farm dams affects local ecosystem health in the Catchment. However, the numbers of licences for surface water extraction and harvesting suggest a level of pressure on Catchment condition.

The extraction and storage of surface waters reduces stream flow and affects the natural variation in flow regimes. There is also evidence that variable stream flow is linked with aquatic ecosystem health. Research undertaken by the former Department of Land and Water Conservation (DLWC) into the impact of farm dams on stream flow concluded that an increase in farm dams has the potential to significantly impact on stream flow particularly under low flow conditions (Sinclair Knight Merz, 1999). Water extraction and farm dams in the Catchment will therefore have an impact in the Catchment.

Future directions

As identified in the 2003 Audit Report, better quantification of actual extraction volumes and the impact of different extraction levels on ecosystem health is required to guide sustainable water resource allocation decisions in the Catchment. This is particularly important in drought conditions where water supplies and ecosystem health are likely to be under pressure and knowledge about trade offs is required in water resource management decisions.

A Water Sharing Plan for the Metropolitan area is presently being developed by the DNR. This plan will include rules on surface water extraction by irrigators and other water uses. The DNR has also commenced a program to require monitoring of actual extraction volumes in the Catchment. When available, these data should be used in conjunction with flow gauging and in-stream ecosystem monitoring such as AusRivAS (see Chapter 5) to provide improved knowledge of the impacts of extraction and farm dams on ecosystem health. This improved knowledge should be used in periodic reviews of Water Sharing Plans in the Catchment.

Recommendation 9: The DNR undertake research into the impact of different levels of water extraction and harvesting on flow regimes and ecosystem health within the Catchment, focusing on the sub-catchments most under pressure from water extraction and water harvesting.

Recommendation 10: The DNR use the results of research and improved knowledge about the impacts of water extraction and water harvesting in periodic reviews of Water Sharing Plans in the Catchment.

Audit of the Sydney Drinking Water Catchment 2005 52

3.2 Groundwater extraction

Background

Groundwater is derived from rain which percolates down through the soil or 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% 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 (Water and Rivers Commission 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.

Management of groundwater resources in the Catchment is mainly limited to monitoring of groundwater levels in the Southern Highlands, although funding has been provided to expand the DNR’s bore monitoring program. There have also been a number of studies on the sustainability of groundwater extraction in the Wollondilly–Nepean aquifers and in sections of the Coxs River catchment.

The DNR 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 no current data on groundwater extraction volumes for all licences in the Catchment. This audit therefore examines the number of groundwater bores in the Catchment. Future audits may also be able to report on actual groundwater extraction volumes.

Findings

There are currently 2,920 licensed groundwater bores in the Catchment, which is an increase of 615 since the 2003 Audit period. The highest number of groundwater bores are located in the Wingecarribee River (priority) sub-catchment, which is also where the highest number of new bores have been licensed during the 2005 Audit period. The Kangaroo River (priority), Mulwaree River (priority), Nattai Creek and Bungonia Creek sub-catchments also have high numbers of groundwater bores (see Map 3.2 for location of licensed groundwater bores).

As noted in the 2003 Audit Report, it is likely that the volume of groundwater extraction has increased as a result of the drought although there is no direct data to confirm this. However, the DNR monitoring bore network is revealing an overall decline in the standing water levels over the past few years, with no apparent response to individual rainfall events and seasonal variation of up to 10.5 metres (Pritchard et al. 2004). These monitoring results suggest that large volumes of water are being extracted by bores, particularly during the summer months (Pritchard et al.2004).

The DNR’s groundwater monitoring in the Southern Highlands indicates that levels have declined in this area since 1999. However, the DNR reports that there was a partial recovery in levels during 2003. There has

Map 3.2 – Groundwater bores before and after 2003 in the Sydney Drinking Water Catchment

Managing Water Resources 53

been a 60% increase in the number of groundwater licence applications in the Southern Highlands since 1998, due to the restriction of new water access licence applications and the prevailing drier conditions (Pritchard et al 2004).

The DNR undertook a review of the status of the groundwater resources in the Southern Highlands in 2004. The study area was totally within the Catchment in the Nattai River, Upper Nepean River, Wingecarribee River (priority), Kangaroo River (priority) and Wollondilly River (priority) sub-catchments. This review identified:

• declining water levels within some monitoring bores of up to ten metres

• parts of the study area are likely to have reached their sustainable limit

• lack of knowledge on actual water extraction (i.e. volumes, rates, timing) from licensed bores, particularly high yield bores

• limited understanding of the linkages between groundwater and the dependent ecosystems

• contamination potential from the overlaying saline Wianamatta Group shale unit, affecting the Hawkesbury sandstone aquifer, due to poor bore construction procedures.

An embargo was introduced in May 2004 for new groundwater licences for commercial purposes in specified areas of the Southern Highlands.

The DNR has also developed estimates of sustainable yield in the Coxs River catchment to assist the Coxs River Water Management Committee to complete a draft of groundwater sharing rules for the Coxs River.

Implication

A combination of increased groundwater extraction licensing, declining water levels, un-monitored extraction and continuing drought conditions, are likely to be resulting in increased pressure on groundwater dependent ecosystems in the Catchment. Groundwater dependent ecosystems in the Southern Highlands, Kangaroo River (priority), Werriberri Creek (priority) and Wingecarribee River (priority) sub-catchments are likely to be under pressure.

As identified in the 2003 Audit Report, the extent of demand for groundwater is not well quantified. There is also limited knowledge about the impact of groundwater extraction on groundwater dependent ecosystems.

Future directions

More information is needed about actual groundwater extracted in the Catchment, and the cumulative impact of groundwater extraction in each aquifer, to enable decisions about sustainable use of groundwater.

The implementation of the NSW Water Extraction Monitoring Policy will provide data about the actual groundwater extraction volumes. Priority should be given to metering and reporting of groundwater extraction volumes in the Southern Highlands, Kangaroo River (priority), Werriberri Creek (priority) and Wingecarribee River (priority) sub-catchments.

The development of a catchment-wide groundwater bore monitoring network would also assist in understanding the impact of extraction on water levels and groundwater quality and enable the assessment of sustainable yields for these resources. As indicated in Chapter 1, the NSW Government has recently allocated funds for the installation of new monitoring bores across NSW and funds have been specifically assigned for the Shoalhaven and Hawkesbury–Nepean catchments. The DNR should give consideration to locating new monitoring bores in the Southern Highlands, Kangaroo River (priority), Werriberri Creek (priority) and Wingecarribee River (priority) sub-catchments.

Groundwater Sharing Plans are currently being prepared for areas in the Catchment and are expected to be complete by 2006.

Audit of the Sydney Drinking Water Catchment 2005 54

Recommendation 11: The DNR require groundwater extraction volume metering and reporting with a priority for implementation on licences in the Southern Highlands, Kangaroo River (priority), Werriberri Creek (priority) and Wingecarribee River (priority) sub-catchments.

Recommendation 12: The DNR give consideration to locating new monitoring bores in the Southern Highlands, Kangaroo River (priority), Werriberri Creek (priority) and Wingecarribee River (priority) sub-catchments.

Surface and groundwater interaction

The specific dynamics of the interaction between surface and groundwater systems in the Catchment is not well documented or understood. This interaction is particularly important to groundwater dependent ecosystems, to base flow and possibly to surface water quality during low flow and drought conditions. A hydrological model that investigates the interaction between surface and groundwater systems that can be used to manage surface and ground water extraction from the Catchment will be an essential tool in developing and refining Water Sharing Plans.

Recommendation 13: The DNR develop a hydrological model that investigates the interaction between surface and groundwater systems that can be used to manage surface and groundwater extraction from the Catchment.

Managing Water Resources 55

State of the Catchment

3.3 Water for the environment

Background

‘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 supply the needs of the environment to maintain ecosystem function by mimicking the elements of natural variability between high and low flows (Nature Conservation Council of NSW, 2003). Flow regime is a key driver of aquatic ecosystem health. Changes in the flow regime can cause changes to river geomorphology, habitat, water quality and greatly influence the riverine biota. Environmental water is the term used in the audit to describe water that is protected from extraction by rules and extraction limits.

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 (see 3.1 Surface water extraction) and the construction of dams and weirs in NSW rivers has changed the frequency of natural flow. 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.

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 requirements of its Water Management Licence. The current requirements under the Water Management Licence for releases from dams for environmental flows is a result of the Healthy Rivers 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 flow to rivers and streams outside the Catchment, while releases from Nepean, Avon, Cataract and Cordeaux Dams flow within the Catchment 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 Wingecaribee and Wollondilly Rivers (priority) sub-catchments to Lake Burragorang.

This audit examines:

• dams, weirs and other barriers to flow in the Catchment

• total volume of water released from SCA storages during the audit period

• total volume of water released for environmental purposes in the Catchment

• the management of bulk water transfers in the Catchment.

Findings

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 conditions appropriate for algal blooms. The majority of weirs and barriers in the Catchment are located in the Upper Wollondilly River (priority), Kangaroo River (priority), Wingecarribee River (priority), Werriberri Creek (priority), Upper Coxs River (priority) sub-catchments and the upper section of the Bungonia Creek sub-catchment around Barbers Creek (Map 3.3). See Chapter 5 for details on weir review and weir removal programs.

Audit of the Sydney Drinking Water Catchment 2005 56

Releases from SCA storages

The total volume of water released or extracted from major SCA storages is summarised in Figure 3.3. The total volume of water released or extracted from each of the Nepean, Woronora, Fitzroy Falls and Tallowa Dams and Wingecarribee Reservoir has increased since 2001. The total volume of water released or extracted from each of the Waragamba Dam and Broughtons Pass Weir has decreased since 2001, due to water restrictions on consumptive use. The volume of water released or extracted from the remaining major storages (Cataract Dam, Cordeaux Dam, Avon Dam and Pheasants Nest Weir) has had little or no change since 2001.

Figure 3.3 – Total volume (megalitres) of water released/extracted from SCA storages, 2001 to 2005

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Source: SCA 2005

Water for the environment

The SCA is required by its Water Management Licence to release specified volumes of water for environmental flow purposes from Avon Dam, Broughtons Pass Weir, Cataract Dam, Cordeaux Dam, Nepean Dam, Pheasants Nest Weir, Warragamba Dam and Wingecarribee Dam (DLWC 2001). The SCA has met its environmental release requirements 99.7–99.9% of the time since the commencement of the Water Management Licence in April 2001. In 2001–02 total flows of 232,960 ML were released from SCA major storages, including environmental flow releases of 91,585 ML. During 2002–03 the SCA released a total of 279,597 ML of bulk water from its major storages to rivers of which 80,956 ML was released specifically for environmental flow purposes. During 2003–04, 302,894 ML of water was released downstream from major storages, 87,038 ML of which was released to meet riparian and environmental flow requirements.

Tallowa Dam (Figure 3.4 and 3.5) has the highest volume of water released for environmental and riparian purposes, although this has decreased since 2001 due to water restrictions on consumptive use. There has also been a small decrease in the volume of water released from Fitzroy Falls Dam since 2001, and an increase in environmental releases at Warragamba Dam in 2002–03 due to the maintenance of flows over Penrith weir (See Figure 3.5).

Map 3.3 – Weirs, gauging stations and barriers in the Sydney Drinking Water Catchment

Managing Water Resources 57

Figure 3.4 – Environmental flows from Tallowa Dam, October 2005

Figure 3.5 – Volume (megalitres) of environmental and riparian water released from water storages, 2001 to 2005

Source: SCA 2005

While outside the 2005 Audit period, the NSW Government recently decided to adjust requirements for environmental flow releases to the Hawkesbury–Nepean catchment in response to the severity of the drought. Environmental releases have been reduced from 33 ML/day to 17 ML/day from Warragamba Dam, 4.4 ML/day to 2.2 ML/day from the Nepean Dam, 1.9 ML/day to 1 ML/day from Cordeaux Dam and 1.3 ML/day to 0.65 ML/day from Cataract Dam. Environmental flow release requirements for the Shoalhaven and Woronora Rivers have not been changed.

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Audit of the Sydney Drinking Water Catchment 2005 58

Bulk water transfer

The volume of water released to rivers from the Wingecarribee Reservoir increased by approximately 257% between both 2001–02 to 2002–03 and 2002–03 to 2003–04 (Table 3.1). This increase was due to the need to transfer large volumes of water during the current drought. The volume of water released between 2003–04 and 2004–05 decreased by 7%.

Table 3.1 – Total volume of water (ML) released from Wingecarribee Reservoir to rivers that flow inside the Catchment.

Storage 2001–02 2002–03 2003–04 2004–05

Wingecarribee Reservoir 8,820 31,687 112,477 104,557

Source: SCA 2005

Note: The volume includes environmental flow releases and customer extractions releases via rivers

The former Department of Infrastructure Planning and Natural Resources (DIPNR) required the SCA under its Water Management Licence to commission an independent assessment of the environmental impacts of bulk water transfers from the SCA’s Upper Nepean storages in 2003. The SCA also commissioned an assessment of the impact of bulk water transfers from the Shoalhaven system into Glenquarry Cut (Figure 3.6) and Doudles Folly Creek in 2003. Both assessments were undertaken by Woodlots and Wetlands.

Figure 3.6 – Glenquarry Cut, for transferring water from Wingecarribee Reservoir to the Nepean River

The Woodlots and Wetlands assessment of the Upper Nepean storages in 2003 covered the river stretches between the Cataract, Cordeaux, Nepean and Avon Dams, and the downstream off-take weirs at Pheasants Nest and Broughtons Pass. The conclusions from the assessment on the impact of bulk water transfers were that:

• there is little evidence that bulk water transfers were affecting stream biota

• it is likely that the geomorphological and chemical similarities between streams above and below the storages outweighed the combined impacts of the storage and the release regimes.

Managing Water Resources 59

The Woodlots and Wetlands assessment of the Shoalhaven bulk transfers in 2004 identified that there is streambank erosion in Glenquarry Creek, although there were likely to be a number of contributing factors including the bulk water transfers, livestock access and lack of riparian vegetation.

Implication

Water for the environment

The total environmental flow releases did not change substantially during the 2005 Audit period. However, the recent Government decision to reduce environmental flows as a drought response highlights that the water resource is limited and that environmental flows need to be well managed to protect Catchment health. The auditor notes that there are two current processes that may assist in managing environmental flows in the Catchment, namely the development of a Water Sharing Plan for the Sydney Region (including the Catchment) and the Weir Review program (see Chapter 5).

The Water Sharing Plans will include mechanisms such as requirements for environmental flow releases from storages and weirs and cease-to-pump rules to protect low flows. Cease-to-pump levels will reflect the sensitivities of various sub-catchments and will be set according to the methodology proposed by DNR and agreed by other water agencies including DEC and the NSW Department of Primary Industries (NSW DPI).

Comprehensive information about flows and flow variability will be required for all sub-catchments to support the implementation of extraction rules under the Water Sharing Plan and for assisting in the review of the Water Sharing Plans. This could be achieved through either an extensive gauging network, or using a hydrologic model of the Catchment. The DNR needs to develop and implement systems to provide this capability.

Under the Metropolitan Water Plan improved regimes of environmental releases will also be gradually implemented at SCA storages, and will be reflected in the Water Sharing Plan. The river reaches below SCA’s four upper Nepean Dams are within the Catchment and are expected to show environmental benefits from new flow release arrangements. The requirements on Delta Electricity to release environmental flow will also be reflected in the Water Sharing Plan.

The Water Sharing Plans will be critical to securing water for the environment and in maintaining aquatic and riparian ecosystem health in the Catchment. Continued assessment of flow regimes, water quality and riparian and aquatic ecosystem health should inform periodic reviews of the Water Sharing Plans.

Management of bulk water transfers

The current bulk water transfers through natural watercourses in the Catchment have the potential to affect ecosystem health.

The Woodlots and Wetlands (2003) report on the Upper Nepean transfers made several recommendations in relation to flow regimes of bulk water transfers. The report recommends increasing flow variation to mimic natural flows where possible without compromising security of water quality and quantity, reducing flow to minimal possible discharge volume for a period prior to reducing to base environmental flow conditions and not to vary flow by specified volumes in each day. The DNR has negotiated changes to the Water Management Licence with the SCA to implement many of these recommendations, and these amended rules are effective from October 2005. Continued monitoring of the changes in riparian and aquatic ecosystem health should be undertaken to assess the benefits of these changes, and to inform periodic reviews of the Water Management Licence.

The Woodlots and Wetlands (2004) recommendations for the Shoalhaven transfers related to preventing stock access to Glenquarry Creek and Doudles Folly Creek, improving vegetative cover, weed removal, providing rock armour for bank stability in certain locations and considering the needs of platypus breeding seasons and requirements in regulating transfers. Since the time of this assessment, the NSW Government has prepared the Metropolitan Water Plan (2004) which proposes to pipe or tunnel bulk water transfers from the Shoalhaven to Lake Avon by 2009, thereby averting the need for run-of-river transfers in Glenquarry

Audit of the Sydney Drinking Water Catchment 2005 60

Creek and Doudles Folly Creek. The SCA has no interim plans for erosion control, but does consider platypus breeding requirements in its operating protocols for transfers by reducing the allowable flow rate in Shoalhaven bulk water transfers during platypus breeding seasons in spring and summer.

The pipes or tunnels proposed in the Metropolitan Water Plan (DIPNR 2004) to transfer bulk water from the Shoalhaven system by 2009 are likely to address the pressures on ecosystem health caused by run-of-river bulk water transfers through Glenquarry Cut and Doudles Folly Creek. However, until these works are installed and operating, the pressure remains on riparian and aquatic ecosystem health as identified by both the 2003 Audit Report and the Woodlots and Wetlands report (2004). The SCA advises that it is currently developing the scope of works to further characterise the impacts of erosion due to transfer flows in the Glenquarry Cut, and understanding the mechanisms driving these impacts to enable a targeted remedial response. The SCA should proceed with this work and concurrently implement measures recommended by the Wetlands and Woodlots (2004) for rock armoury and vegetative stabilisation as an interim measure to reduce streambank erosion caused by bulk water transfers until either:

i) the transfer pipes or tunnels are operational, or

ii) there is better knowledge from studies into the mechanisms causing erosion in this location.

Recommendation 14: The DNR develop and implement systems for measuring and reporting of flow and flow variability for all sub-catchments to support the implementation of extraction rules and periodic review of the Water Sharing Plans.

Recommendation 15: The SCA implement measures recommended by the Wetlands and Woodlots for rock armoury and vegetative stabilisation in Doudles Folly Creek and Glenquarry Creek as an interim measure to reduce streambank erosion caused by bulk water transfers.

Managing Water Resources 61

Actions and Response

Response to issue

Sustainable water resource management needs to focus on water availability for human uses, as well as for the needs of the environment. Water resource management requires an understanding of the complex interaction between water availability, extent and timing of human needs, and the natural variability which supports ecosystem function and health. This section covers the major actions aimed at managing water resources within the Catchment. These include:

• programs to understand and manage water resources

• programs to encourage more efficient water use

• programs to manage and minimise impacts of bulk water transfers on the health of the ecosystem

• programs to address drought conditions.

Programs to understand and manage water resources

The Metropolitan Water Plan (DIPNR 2004) was prepared by the NSW Government to ensure Sydney’s water needs over the next 25 years, taking into account anticipated population growth, climate change and water needed for the environment.

The DNR is currently co-ordinating the development of a Sydney Metropolitan Water Sharing Plan under the Water Management Act 2000. Water Sharing Plans are statutory plans that will be in effect for 10 years and reviewed after five years. The Sydney Metropolitan Water Sharing Plan will secure water for urban and rural consumption as well as include new rules for environmental flow regimes. The Sydney Water Sharing Plan will include a water benchmark which indicates how much water can be sustainably provided to Sydney residents, businesses and irrigators. The Kangaroo River Water Sharing Plan has already been gazetted in February 2003, providing Shoalhaven City Council with a water entitlement of 85 ML per year for the Kangaroo River.

The Hawkesbury–Nepean River Management Forum (HNRMF) and the Independent Expert Panel on Environmental Flows were established to advise Government on environmental flow regimes for the Hawkesbury–Nepean River System. The HNRMF and the Independent Expert Panel on Environmental Flows submitted a final report to the Minister in March 2004. This report was used to inform proposed new environmental flows included in the Government’s Metropolitan Water Plan (DIPNR 2004). The Metropolitan Water Plan includes environmental flow releases from Avon Dam of 6 gigalitres per year, increasing environmental flows from the Warragamba Dam from 2009, and improving environmental flow releases of approximately 26 billion litres per annum at Cataract, Cordeaux and Nepean dams from 2010. The Water Sharing Plan will be critical to protecting water for the environment both in the Catchment and below the Catchment where there are significant pressures resulting from a lack of flow.

The DNR has prepared the NSW Water Extraction Monitoring Policy in 2005 which outlines principles for monitoring of surface and groundwater throughout NSW. Under the Metropolitan Water Plan, the DNR has developed the Hawkesbury–Nepean Water Extraction Monitoring Strategy which includes a metering program for licensees with surface water extraction entitlements greater than 200 ML per year and monitoring program (using pump hour meters or log books) for smaller users in the Sydney area. This program will be implemented by 2007 and provide accurate information about the actual volumes of surface water extraction for the first time. All groundwater licensees, except those for domestic and stock extraction, have also been required to install meters. This information will be vital to enabling robust reviews of the Water Sharing Plans and in the regulation of water extraction licences. The DNR has also developed a Water Information Exchange which provides for two way electronic communication of water monitoring data between licensees and DNR.

Audit of the Sydney Drinking Water Catchment 2005 62

The Coxs River Water Management Committee drafted recommended water sharing provisions for surface water in the Coxs River Valley (including the Kowmung River sub-catchment) during the 2005 Audit period. These recommendations are planned to be included in the Sydney Water Sharing Plan.

The DNR is undertaking research into the linkage between flows and river health in the Kangaroo River, and Delta Electricity is assessing ecosystem responses in the Coxs River to the changes of environmental flow required by its Water Management licence.

The Department of Energy, Utilities and Sustainability (DEUS) prepared Integrated Water Cycle Management (IWCM) Guidelines in 2004 to assist local water utilities to integrate the management of water supply, sewerage services and stormwater management. The DEUS is currently co-ordinating twelve IWCM pilot projects including projects in the Wingecarribee River (priority) sub-catchment and one in Kangaroo Valley.

Programs to manage and minimise impacts of bulk water transfers on the health of the ecosystem

The SCA is in the process of reviewing its bulk water transfer strategy which includes undertaking an environmental risk assessment for all SCA releases. Environmental monitoring of the SCA’s transfer regime is continuing as part of the review.

The DNR and the SCA have investigated the impacts of Shoalhaven and Upper Nepean bulk water transfers, and responses to many of the findings of these investigation are being implemented as previously outlined in this Chapter.

The Metropolitan Water Plan (DIPNR 2004) proposes two pipelines or tunnels to transfer water from Tallowa Dam on the Shoalhaven River to Sydney dams. These measures would reduce the current impacts of bulk water transfers on ecosystem health. The Metropolitan Water Plan anticipates that these pipelines or tunnels will be completed by 2009, although a community consultation process has recently been commenced to further consider the nature of Shoalhaven bulk water transfers.

Programs to encourage more efficient water use

More efficient use of water drawn from the Catchment can reduce the pressures on the Catchment, particularly during drought periods. There are many programs operating within and outside the Catchment to improve water use efficiency including:

• In July 2004, the Government implemented the BASIX (Building Sustainability Index) scheme which requires new houses built in Sydney to reduce mains-supplied water consumption by 40% compared to the current average for similar sized homes. The same requirement was also introduced from February 2005 for new apartment blocks and other multi-dwelling buildings.

• Water Efficiency Labelling and Standards (WELS) Scheme applies a national mandatory water efficiency labelling and minimum performance standards to household water-using products. Mandatory registration and labelling will apply to washing machines, dishwashers, toilet equipment, showers and tap equipment from 1 July 2006.

• Sydney Water Corporation has established a Rainwater Tank Rebate Scheme to encourage businesses, schools and the community to install rainwater tanks within its area of operation, and to encourage connection of rainwater tanks to toilets and/or washing machines.

• Goulburn Mulwaree City Council, Palerang Council and Wingecarribee Shire Council require all new developments to install rainwater tanks. Wollondilly Shire Council is waiving fees for the installation of rainwater tanks bigger than 10,000L. Goulburn Mulwaree City Council also offers rebates on the purchase of water efficient washing machines, shower heads and dual flush toilets.

Managing Water Resources 63

• The NSW Government’s Every Drop Counts business program has found that water savings of 10 to 30% can be achieved by businesses. This program will continue to support businesses to become more efficient.

• The NSW Government has funded a range of education programs on ways to save water. Programs implemented to date include the drought-related ‘Go Slow on the H2O’, and specialised schools programs by Sydney Water.

• Goulburn Mulwaree Council has also installed a Wet Weather Storage Pond for treated effluent at Gorman Road which can provide up to 3 months of storage for indirect reuse in the Council area.

There are two specific initiatives under the Water Reform Structural Adjustment Program for improving efficiency of irrigation:

• the NSW DPI WaterWise on the Farm program aims to improve the capacity of irrigation farm managers to adjust to water reforms primarily through the adoption of best irrigation management practices and technologies

• the NSW DPI has established a Water Use Efficiency Unit to provide information and advice to irrigators and government on water use efficiency, water access and licensing.

Programs to address drought conditions

Sydney is currently in its worst drought since the 1930s. The NSW Government’s response to increase Sydney’s water supply is outlined in the Metropolitan Water Plan (DIPNR 2004) and includes:

• accessing deep water at the bottom of dams at Avon, Warragamba and potentially Nepean Dams

• increasing bulk water transfers from Shoalhaven to provide an additional 50–110 gigalitres of water to Sydney’s water supplies, although this is subject to a current community consultation process

• investigating sources and using groundwater to augment supply in droughts. These investigations will also increase knowledge about the extent of groundwater in the Catchment and its interaction with surface water systems

• constructing a desalination plant if required.

Gaps in the response

There has been significant progress on improving water resource management in the Catchment since the 2003 Audit, with clear policy positions outlined in the Metropolitan Water Plan, and the array of water efficiency programs. There has also been steady progress in developing policies and implementing programs for metering of water extraction, which will provide valuable information in understanding water use within the Catchment. These programs need to be complemented with coordinated research of the impact of different extraction levels and flow regimes on riparian and aquatic ecosystems in the Catchment. This research should seek to improve the understanding upon which Water Sharing Plans and other water resource initiatives in the Catchment are reviewed and refined (See Recommendation 10).

Systems for measuring and reporting of flow and flow variability for all sub-catchments are required to support the implementation of extraction rules and periodic review of the Water Sharing Plans (See Recommendation 14).

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Chapter 4 Land Condition

Key Points

Indicator Status of Indicator

4.1 Changes in land use The number of SEPP 58 development applications decreased from the 2003 Audit period.

Large areas of agriculture and increased urbanisation and rural residential development may put pressure on water quality within the Catchment, unless best management practices are adopted.

4.2 Sites of pollution and potential contamination

A risk assessment of potentially polluting sites within Catchment was undertaken in the 2005 Audit period, and actions to progressively address high risk sites are continuing.

4.3 Soil erosion There is no updated information on actual and estimated soil erosion in the Catchment. Eleven percent of the Catchment has very high or high estimated rill or sheet soil erosion.

4.4 Dryland salinity A small area of the Catchment (2.8%) is susceptible to salinity.

Localised salinity has been identified in 0.14% of the Catchment during the 2005 Audit period.

Land condition can directly affect water quality and ecosystem health. Land condition is a function of the inherent characteristics of land, natural processes such as drought, flood, human land use and land management practices. This audit focuses on:

• human induced pressures on land condition; namely land-use change and sites of potential pollution and contamination

• the state of soil erosion and dryland salinity risks in the Catchment.

Audit of the Sydney Drinking Water Catchment 2005 66

Pressures in the Catchment The primary human induced pressure on land condition in the Catchment is land use and land-use change. The land uses in the Catchment include varying densities of urban development, variable types and intensity of agricultural activities, extractive industry, electricity generation and Special Areas enclosing drinking water impoundments. When poorly managed, human land use can cause erosion, degradation and contamination of soil, dryland salinity, and the loss of riparian zones and habitat which can ultimately impact Catchment ecosystems and water quality. Examples of human land use and activities that can cause risk of impacts are:

• Urbanisation and rural residential development, especially during the site preparation and construction phase when vegetation is cleared and soil is disturbed, increasing the risk of soil erosion.

• Industrial activities, which if inappropriately managed can have significant impacts on land condition. Activities including extractive industries, waste disposal, and intensive livestock industries can cause land pollution or contamination, which may spread to other areas including water bodies.

• Underground mining, particularly long-wall coal mining can cause subsidence, this can have serious impacts on the environment, including soil erosion, diversion of water flow, reduction in water quality, and physical disturbance of the geological and built environments.

Land use and land use change at a sub-catchment and catchment scale has a potentially cumulative impact on land condition, water quality and ecosystem health. The extent to which each activity actually alters the natural landscape in the Catchment depends on the inherent risks of that land use type, the intensity of the land use and the level and appropriateness of management practices adopted at each site. This audit assesses the pressures to land condition that are caused by land use on a Catchment-wide scale, as well as sites of potential pollution or contamination in the Catchment.

4.1 Changes in land use

Background

A clear understanding of land use within the Catchment is critical in identifying likely impacts on water quality in drinking water storages. Changes in land use includes transferring from one type of land use to another or changing 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 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 undertaken at a frequency which enables an assessment of land use change at two-year audit intervals. Further, land use changes over a two-year audit period are likely to be relatively minor on a Catchment-wide scale. The assessment of land use change at a Catchment scale is therefore a useful longer term measure of the pressures on land condition. The former Department of Infrastructure Planning and Natural Resources (now DNR) carried out land use mapping in 2000 in the Catchment at a more descriptive scale than was presented in the 2003 Audit Report. The 2005 Audit Report therefore presents the more updated land use information in Map 4.1. The audit has also examined the number and type of SEPP 58 development applications* submitted to the SCA during the 2005 Audit period as a surrogate measure of short-term land use change.

* SEPP 58 applies to specified development applications in the Catchment, which require the concurrence of the SCA’s Chief Executive Officer.

Map 4.1 – Land use and percentage of area in the in the Sydney Drinking Water Catchment

Land Condition 67

Findings

Land use

Land use across the Catchment is shown in Map 4.1. The Upper Wollondilly River (priority), Mulwaree River (priority), Wingecarribee River (priority), Reedy Creek and Braidwood Creek sub-catchments have large areas of grazing or improved pasture. Large urban areas are located at Goulburn, Bowral, Moss Vale, Lithgow and Katoomba. There is also a large area of rural residential in the Nerrimunga Creek sub-catchment.

SEPP 58 applications

There was a 19% decrease in the total number of SEPP 58 development applications submitted to the SCA in the 2005 Audit period compared to the 2003 Audit period.

The level of urbanisation in the Kangaroo River (priority), Wingecarribee River (priority) and Wollondilly River (priority) sub-catchments is increasing with the greatest number of SEPP 58 development applications received for dwellings and subdivisions during the 2005 Audit period (see Figure 4.1), although this has slowed from the 2003 Audit period. The number of SEPP 58 applications received for dwellings and subdivisions in the Bungonia Creek, Upper Nepean River, Werriberri Creek (priority) and Nattai River sub-catchments decreased during the 2005 Audit period (see Figure 4.1). The Jerrabattagulla Creek, Kowmung River, Boro Creek, Mid Shoalhaven River, Nerrimunga River, Braidwood Creek, Little River, Mid Coxs River (priority), Upper Wollondilly River (priority) and Upper Coxs River (priority) sub-catchments all had increases in the number of SEPP 58 applications received for dwellings and subdivisions (see Figure 4.1).

The Upper Nepean River, Kangaroo River (priority), Mid Coxs River (priority), Wollondilly River (priority) and Wingecarribee River (priority) sub-catchments had the greatest number of SEPP 58 development applications that did not include dwellings or subdivisions (see Figure 4.2). These developments include agriculture, effluent/biosolid disposal, forestry, mining, poultry farm, tourism and vineyards. There was a decrease in the number of SEPP 58 development applications that did not include dwellings or subdivisions in the Wollondilly River (priority), Upper Wollondilly River (priority), Nattai River and Wingecarribee River (priority) sub-catchments (see Figure 4.2).

Figure 4.1 – Number of SEPP 58 development applications for dwellings and subdivisions per sub-catchment for the 2003 and 2005 Audit periods

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Audit of the Sydney Drinking Water Catchment 2005 68

Figure 4.2 – Number of SEPP 58 development applications excluding dwellings and subdivisions per sub-catchment for the 2003 and 2005 Audit periods

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Implication

The number of SEPP 58 applications decreased during the 2005 Audit period. However, a large number of urban, rural residential and commercial developments are still occurring in the Wingecarribee River (priority), Wollondilly River (priority) and Kangaroo River (priority) sub-catchments. This may put pressure on water quality, ecosystem health and land condition in these sub-catchments unless specific management practices are adopted or incorporated to mitigate the potential impacts of vegetation clearing, soil erosion, stormwater and sewage management associated with these developments. Other changes in land use such as improvement 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 significantly change the impact of activities for better or worse but again these are difficult to quantify.

A number of Councils in the Catchment predict further residential developments over the next 10 years:

• Goulburn Mulwaree City Council is predicting growth in Marys Mount and Taralga in the Wollondilly River (priority) sub-catchment and Marulan in the Bungonia Creek sub-catchment

• Lithgow City Council is predicting growth in South Bowenfels and Pottery Estate in the Upper Coxs River (priority) sub-catchment

• Wingecarribee Shire Council is predicting growth in Colo Vale and Mittagong in the Nattai River sub-catchment and Moss Vale in the Wingecarribee River (priority) sub-catchment.

The Department of Planning (formerly DIPNR) is revising the Sydney to Canberra Corridor Strategy which includes areas within the Catchment in the Wingecarribee, Wollondilly and Upper Lachlan local government areas (LGAs).

Land Condition 69

Future directions

Given the anticipated rate of land use change across the Catchment it is envisaged that land use maps would 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 such as nutrient export potential. 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 relatively contemporary.

Recommendation 16: The SCA and the Department of Planning prepare a detailed land use map at five year intervals. The resolution and categorisation should be sufficient so that change from the previous map can be determined.

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 potentially lead to overall improved outcomes especially where degraded landscapes are rehabilitated and best practice water sensitive design principles are implemented. Therefore, it would be useful to develop indicators of the effectiveness of different management practices and levels of management to assist in targeting responses to those sites where improved practice is possible, and where improved practice can assist in addressing know water quality issues or pressures on ecosystem health.

The SCA’s 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 practice. The effectiveness of different management practices in different land use types need to be benchmarked to enable this next step. Various agencies have already published best management practice guidelines and the SCA has a Current Recommended Management Practices (see Actions and Response section in this Chapter). Further benchmarking and guidelines should be developed for remaining high risk activities and management practices.

Recommendation 17: The SCA identify high risk activities where there are no documented best practice benchmarks, and work with relevant agencies, industries and landholders to develop and implement recommended management practices.

4.2 Sites of pollution and potential contamination

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 within the Catchment that have a potential to contaminate land and pollute water.

This audit examines:

• sites of potential pollution and contamination identified during the audit period

• risk assessment of the potential sites of pollution and contamination during the audit period

• level of compliance during the audit period of sites licensed to discharge to waters under the POEO Act

• new remediation and rehabilitation works at sites of pollution or contamination during the audit period.

Audit of the Sydney Drinking Water Catchment 2005 70

Findings

Sites of potential pollution or contamination

The SCA prepared the Pollution Source Risk Management Plan in December 2000 which identified activities that were expected to occur in the Catchment and that have the potential to pollute land. The SCA then commissioned assessments of nine potentially high risk industry types in the Catchment to identify specific sites of potential pollution in the Catchment. These assessments are known as the Environmental Assessment of Sites and Infrastructure (EASI) assessments. 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 1,776 sites of pollution or potential contamination in the Catchment.

There are four sites in the Catchment that are listed on the EPA’s Contaminated Land Record under section 58 of the Contaminated Land Management Act 1997. The EPA issued remediation orders to the Waste Oil Storage facility in Larbert, the former Shale Oil Plant at Mittagong and the former shale oil refinery at Hartley Vale and issued an investigation order to the Joadja Shale Oil Refinery. The Hartley Vale Shale and the Joadja Shale Mines are on the (former) Department of Mineral Resources Derelict Mine List as sites in need of remediation works to prevent contamination of waterways. There have been investigations into the nature and extent of contamination at the former oil shale refinery at Hartley Vale during the 2005 Audit period. The remediation of the former shale oil plant at Mittagong commenced in February 2005 and was completed in June 2005 using funds from the Environmental Trust.

Risk assessment

Since the EASI reports were prepared in 2000 there has been an additional 80 sites added to the list of sites of pollution or potential contamination. The SCA has carried out a risk assessment process of these 1,856 sites and rated 57 sites as very high risk, 212 sites as high risk, 346 sites as medium risk, 599 sites as low risk and 521 sites as negligible risk. The type of activity in the very high, high and medium risk categories are presented in Table 4.1. The locations of very high, high or medium risk sites are shown in Map 4.2 and 4.3.

Map 4.2 – Sites of pollution or potential contamination with a medium, high or very high risk rating in the Sydney Drinking Water Catchment

Map 4.3 – Mines and quarries with a medium, high or very high risk rating in the Sydney Drinking Water Catchment

Land Condition 71

Table 4.1 – Type and number of potentially polluting sites rated very high, high and medium risk to water quality by SCA in the Catchment

Type of site Very High High Medium Type of site Very

High High Medium

Commercial and Manufacturing Facilities Intensive Livestock

Industries

Automotive sites 7 4 Aquaculture 1

Farm & grain supply 1 Dairy 10 12 13

Food manufacture 2 Feedlots 1

Metal industry 1 Saleyard 1 4

Timber Industry 3 7 Horses 6 3

Construction Industry 1 5 Piggery 2

Poultry 5 1

Domestic animals 2

Intensive Horticulture/Forestry Sewage and Water

Treatment

Vegetable growing 11 3 Sewage treatment plant 1 1 9

Cropping 1 4 Water pumping station 5 9

Grapes 5 9 27 Sewage pumping station 6 15 68

Flowers 2 1 Water filtration plant 3 2 3

Forestry 2 1 2 Effluent irrigation 2 6

Fruit 2 28 16 Biosolids disposal 2 1 6

Nursery 4 4 Swimming pool 1 2

Olives 7 15 Small STP 1 4 2

Nuts 1 1 Pit toilet 2

Berries 1 2 4 Recreation area 1 2

Potatoes 2 13 1

Mushrooms 1

Waste Disposal Telecommunications and Energy Production

Operating landfill 1 2 7 Substation 3 6

Former landfill 1 Power station 1

Recycling drop off 5 1

Transfer station 1 Commonwealth Facilities

Waste storage 2 Defence range 1

Illegal dumping site 1

Mines 3 9 38 Quarries 12 41 55

Derelict mines 3 4

Source: SCA 2005

Audit of the Sydney Drinking Water Catchment 2005 72

The majority of the sites of potential contamination in the very high, high and medium risk categories are located in the Wingecarribee River (priority), Kangaroo River (priority), Werriberri Creek (priority) and Upper Coxs River (priority) sub-catchments (see Map 4.2). The majority of the mines and quarries in the very high, high and medium risk categories are located in the Kangaroo River (priority), Bungonia Creek, Lake Burragorang, Upper Nepean River and Upper Coxs River (priority) sub-catchments (see Map 4.3). The waste facilities and manufacturing sites are primarily located in the towns of Bowral, Moss Vale, Lithgow and Braidwood.

In the 2003 Audit period, the Mining EASI report found 26 mining sites that warranted further investigation and follow up by the SCA. During the 2005 Audit period the SCA carried out risk assessment of all 18 sites identified as being within the Catchment (eight sites from the Mining EASI report were found to be just outside the Catchment). The SCA’s risk ranking of these 18 mining sites is presented in Table 4.2.

In addition to the sites listed in Table 4.2, the Yerranderie Silver Field is the number one site published in the (former) Department of Mineral Resources (DMR) top 50 derelict mine sites list of NSW. The Yerranderie Silver Field was rated as high risk to water quality by SCA.

Table 4.2 – Mines identified in the Mining EASI report, with EPA licence number and SCA’s risk assessment

Mine EPA Licence No.

Risk Rating Mine EPA Licence No.

Risk Rating

Angus Place Colliery 467 Medium Nattai Bulli Colliery High

Bellambi Colliery Very High Nattai North Colliery High

Berrima Colliery 608 Medium Oakdale Colliery High

Blue Mountains Colliery 636 Medium Ruby Creek Mine Medium

Brimstone Colliery Very High Springvale Colliery 3607 Medium

Cordeaux Colliery 611 Very High Valley No.1, 2 & 3 High

Enhance Place 6312 Medium Wallerawang Colliery 4911 Medium

Hermitage Colliery / Fernbrook Pit top

Medium Wollondilly Colliery High

Lithgow Valley (Cullen) 10341 Medium Wollondilly Washery 641 High

Source: SCA and DEC 2005

Compliance levels of sites licensed under the POEO Act

The EPA regulates major point sources of potential pollution using Environment Protection Licences issued under the POEO Act. Activities that require an Environment Protection Licence include heavy industry, sewage treatment, electricity generation and waste facilities. The licences include comprehensive requirements for pollution control, monitoring, and reporting. There are 88 sites in the Catchment that are licensed under the POEO Act. A summary of the non-compliances with discharge limits and monitoring requirements for licensed sites during the 2005 Audit period is presented in Table 4.3.

Nine of the mines identified in the Mining EASI report have Environment Protection Licences and seven of these had non-compliances during the 2005 Audit period (see Table 4.3). The mine site non-compliances included exceedences of discharge limits for pH, BOD, conductivity, TSS, oil and grease, iron and manganese. Only six other licensees in the Catchment had non-compliances during the 2005 Audit period, and non-compliances at four of these sites related to a breach of specified monitoring requirements.

Audit of the Sydney Drinking W

ater Catchm

ent 2005 73

Table 4.3 – Discharge limit and monitoring non-compliances for the 2005 Audit period at sites licensed under the POEO Act

PH limit Discharge BOD Conductivity Total P

Total N TSS Oil and

grease Fe Mn Monitoring

2003–04 X Angus Place Colliery

2004–05 X 2003–04 X Berrima Colliery 2004–05 2003–04 X X X X Enhance Place Colliery 2004–05 2003–04 X X X Springvale Colliery 2004–05 X X X X X 2003–04 X X Wallerawang Colliery 2004–05 2003–04 X Woodlawn Mine 2004–05 2003–04 X X Appin Power Station 2004–05 2003–04 X Wallerawang Power Station 2004–05 2003–04 X Goulburn Landfill 2004–05 2003–04 X Lithgow Solid Waste Facility 2004–05 2003–04 X Crisps Creek Inter Modal Facility 2004–05

Source: DEC 2005

74 Land Condition

There are eleven licensed quarries in the Catchment and none of these sites reported non-compliances in the 2005 Audit period (see Table 4.4).

Table 4.4 – Quarries licensed under the POEO Act in the Catchment and SCA’s risk assessment Quarry EPA

Licence No. Risk

Rating Quarry EPA

Licence No. Risk

Rating

Braidwood Sand Pit 4483 Low Marulan Pit 944 Medium

Bunnygalore Quarry 4249 Low Penrose Sand Quarry 4720 Low

Exeter Quarry 870 High Rivervale 3517 Low

Hartley Rhyolite Quarry 12323 Low Soapy Flat Sand Pit 3132 Low

Kangaloon Flat Sand Pit 4232 High Welby Quarry 2223 Low

Marulan Quarry 1371 High

Source: SCA and DEC 2005

DEC and the SCA have been working to address licensed mine and extractive industry sites identified by the SCA as potential ‘hot spots’. A brief summary of the issues or environmental risks identified and DEC actions on each site are in the Actions and Response section of this Chapter.

There were four mining-related SEPP 58 development applications made during the 2005 Audit period, which included three ancillary applications in the Upper Nepean River sub-catchment and one Part-4 application in the Mid Coxs River (priority) sub-catchment.

Implications

There are a large number of activities in the Catchment with the potential to impact land condition and water quality if they are not appropriately managed. These sites are concentrated in the Kangaroo River (priority), Upper Coxs River (priority), Werriberri Creek (priority), Wingecarribee River (priority), Bungonia Creek, Lake Burragorang and Upper Nepean River sub-catchments. The SCA should continue to work with relevant agencies, operators and landholders to address sites identified as very high, high and medium risk to water quality.

Future directions

The assessment of actual risk at sites of potential pollution and contamination should be continued, and actions implemented to reduce risks where necessary. The risk of pollution and contamination at operational sites should be reassessed at a frequency commensurate with the inherent risk of the activity type, site specific risks and known performance history of the landholder/operator.

The SCA should be working with relevant agencies, landholders and operators to ensure there are pollution prevention or rehabilitation programs at sites identified as posing a risk to water quality or ecosystem health in the Catchment. The pollution prevention or rehabilitation programs should be formalised where necessary through regulatory instruments such as Environment Protection Licences and Pollution Prevention Notices under the POEO Act, or through formal programs such as derelict mine programs. The SCA should therefore be developing the prevention or rehabilitation programs at each site in consultation with the landholders as well as with other relevant agencies such as the EPA or Councils.

Recommendation 18: The SCA develop pollution prevention or rehabilitation programs at sites identified as very high, high and medium risk to water quality, in consultation with relevant agencies, operators and landholders.

Land Condition 75

Case Study – Woodlawn Mine and Landfill

The Woodlawn Mine is 30 km south of Goulburn in the Mulwaree River (priority) sub-catchment. Open cut mining for copper, lead and zinc at Woodlawn ceased in 1998. The Woodlawn Mine site comprises a 38 hectare mine void (see Figure 4.3), a 110 hectare tailings dam, a 100 hectare evaporation pond, a 40 hectare plant area and rehabilitated waste rock dump and disused mining infrastructure. The mine void has a volume of approximately 25 million m3 and a depth of about 200 m.

Figure 4.3 – Panorama of the Woodlawn void Source: Tri Origin Minerals

Collex has constructed Australia’s first large scale commercial bioreactor landfill facility at the old Woodlawn Mine site. The facility can transform up to 400,000 tonnes of domestic waste from the Sydney Metropolitan area into inert landfill. The waste is deposited into specially constructed cells. Leachate recirculation systems will ensure maximum biodegradation of the waste within each cell. Once capped, methane will be extracted from each cell and converted to electricity within a gas to energy facility (Figure 4.4). The transformation of the domestic waste will produce enough green electricity to power a small city for 50 years. The bi-products of the conversion of methane to energy are carbon dioxide and heat. The carbon dioxide produced is captured and pumped into an on-site glasshouse, boosting agricultural production.

Collex received the first waste at the bioreactor in September 2004. The projected life of the landfill is 75 years.

Figure 4.4 – Cross section of a bioreactor waste-to-energy facility Source: Collex

Audit of the Sydney Drinking Water Catchment 2005 76

State of the Catchment

4.3 Soil erosion

Background

Soil erosion is a natural process that can be accelerated by human activities. The slow rate of soil formation means that soil is effectively a non-renewable resource. Increased rates of erosion can also impact water quality and aquatic ecosystems due to the deposition of sediments and nutrients.

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 wind erosion. The management of areas with erosion risk, and the remediation of areas that are affected by soil erosion, is important in protecting Catchment productivity, water quality and ecosystem health.

Estimated sheet and rill erosion was calculated by the National Land and Water Resources Audit (NLWRA 2001) using the Revised Universal Soil Loss Equation (RUSLE). The following attributes were used in the RUSLE: soil erodibility (data derived from NSW Soil and Land Information System and the Australian Soil Resource Information System); rainfall erosivity (data from National Rainfall erosivity surface); slope gradient and length (derived from the National Digital Elevation model); and ground cover (Satellite imagery from Normalised Difference Vegetation Index – NDVI).

Observed soil erosion is not currently mapped at regular intervals. However, details of erosion management programs during the 2005 Audit period are presented as a short-term measure of change for this indicator.

Findings

No update of actual or estimated sheet and rill erosion was available for the 2005 Audit period. As presented in the 2003 Audit report using information from the NLWRA, 4.9 percent of the Catchment is estimated to have very high risk of sheet and rill erosion, including parts of the Upper Coxs River (priority) and Wollondilly River (priority) sub-catchments. The Upper Wollondilly River (priority), Mulwaree River (priority), Reedy Creek and Braidwood Creek sub-catchments (5.6 percent of the Catchment) also contain areas with high erosion risk (see Map 4.4).

Observing actual erosion is a labour-intensive and time-consuming process and has only been completed in the Braidwood lands. The total area affected by erosion in the Braidwood area is 185 hectares or 1% of total Braidwood area.

The Catchment Protection Scheme administered by CMAs aims to repair severe gully, stream bed and stream bank erosion. During 2004–05 the following erosion management was undertaken in the Catchment:

• 1250 hectares was treated for moderate to severe gully erosion

• 37 kilometres of fences were constructed to protect severe gully and stream erosion from livestock

• 15 flumes were constructed

• 1400 metres of gully was reshaped

• 17 streambed and bank erosion control structures were built

• 9 stable stock access/crossing points were established.

Map 4.4 – Estimated sheet and rill erosion in the Sydney Drinking Water Catchment

Land Condition 77

Implications

There is inadequate information about observed erosion in the Catchment and the location and type of erosion management works in the Catchment. Areas within the Upper Coxs River (priority), Upper Wollondilly River (priority), Wollondilly River (priority), Mulwaree River (priority), Reedy Creek and Braidwood Creek sub-catchments have been identified as the most susceptible to soil erosion. Programs addressing soil erosion need to specifically target these areas to ensure that appropriate strategies and management controls are in place to minimise the risk of erosion, and to respond to actual cases of soil erosion.

Future directions

Erosion management programs need to reduce the risks of erosion as well as manage and rehabilitate actual cases of erosion. The RUSLE provides information about the locations of erosion risk in the Catchment. Programs to minimise the risk of soil erosion should be targeted at areas of high estimated erosion rates.

The only human influenced component of erosion risk in the RUSLE is ground cover. Programs to manage the risk of erosion should therefore be integrated with programs to protect and rehabilitate native and riparian vegetation (see Chapter 5) to obtain multiple benefits from on-ground works.

There is inadequate information about observed erosion in the Catchment, and the location and type of erosion management works in the Catchment. Agencies involved in establishing, funding or implementing erosion control programs should jointly investigate an integrated and systematic methodology for recording the location, type and extent of actual or observed erosion in the Catchment to enable monitoring trends in soil erosion and to guide implementation of rehabilitation programs to protect water quality and ecosystem health (see Recommendation 19).

The location, type and area of all erosion management works in the Catchment should be recorded on a centralised spatial information system to enable the co-ordination of erosion management works between programs and agencies and to maximise the potential for integrating erosion works with other potentially complementary programs such as nutrient reduction and riparian and native vegetation rehabilitation works (see Recommendations 2 and 5).

4.4 Dryland Salinity

Background

Salinity can be a threat to the health and productivity of a catchment, as excessive salinity can be lethal to plants and soil organisms or severely limit their productivity. Salinity occurs when the natural balance and distribution of salt in the landscape is disturbed. The removal of native vegetation through land clearing and the adoption of unsuitable land uses and practices have resulted in rising groundwater tables in some locations. This allows naturally occurring salts to migrate close to the soil surface where they are concentrated by evaporation or discharged into surface waters. Discharges of saline waste water from mines, power stations and STPs are other sources of salts reaching waterways.

The risk of salinity was determined by DIPNR (now DNR) using the Soil Landscapes data for the Catchment. The risk was placed into three categories:

• widespread – areas where saline soils occur or where scalding, salt efflorescence, vegetation dieback, salt tolerant vegetation and water logging can be found

• localised – scattered areas of scalding and indicator vegetation have been noted, or

• no risk – small likelihood of salinity occurring.

DIPNR (now DNR) undertook a Surface Salinity Mapping Project during the 2005 Audit period to map actual cases of dryland salinity in NSW. This mapping of location, severity and extent of dryland salinity

Audit of the Sydney Drinking Water Catchment 2005 78

cases will provide a baseline against which changes can be identified in future audits. Details of sites at which dryland salinity management occurred in the Catchment during the 2005 Audit period is presented as a short-term component of change for this indicator.

Findings

The area of the Catchment with a widespread risk of salinity is 2.8%, located in the Boro Creek, Mid Shoalhaven River and Nerrimunga Creek sub-catchments (see Map 4.5).

To date the Goulburn, Braidwood and Taralga 1:100,000 map sheets within the Catchment have been surveyed for actual salinity as part of the Surface Salinity Mapping Project. From this project the area of the Catchment with observed salinity cases was 2,156.68 ha (0.14%), and was located in the Wollondilly River (priority), Upper Wollondilly River (priority), Mulwaree River (priority), Nerrimunga Creek, Boro Creek, Reedy Creek and Bungonia Creek sub-catchments (see Map 4.5).

11.5 hectares of salinity affected land was treated during 2004–05 under the Catchment Protection Scheme administered by the CMAs.

Implication

The auditor does not consider salinity to be a major issue in the Catchment as the extent of salinity risk is limited and the observed area of salinity is small. However, areas within the Boro Creek, Mid Shoalhaven River and Nerrimunga Creek sub-catchments have been identified as the most susceptible to salinity in the Catchment. Relevant agencies need to ensure appropriate management in high risk areas to prevent salinity from becoming a significant issue in the Catchment. Programs to manage salinity should target these high risk areas, and other locations where land management practices increase the risk of salinity such as at sites where long-term irrigation is practised.

Future directions

The future directions for managing salinity in the Catchment are similar to those outlined for soil erosion. Salinity management programs need to reduce the risks of salinity as well as manage and rehabilitate actual cases of salinity. Programs to minimise the risk of soil salinity need to be developed for sub-catchments and specific locations identified as having widespread and localised risk of developing dryland salinity.

However, there is not complete information about the location and extent of actual salinity cases over the entire Catchment. The Natural Resource Commission (NRC) has agreed on land salinity as a resource condition indicator, and considers that the size of salinity outbreaks should be re-measured every five to ten years and the intensity re-assessed during the re-measurement. The DNR and the SCA should develop systems for recording the location, type and extent of actual or observed salinity. This will enable reporting on this type of indicator, assessment of monitoring trends and development of targeted rehabilitation programs to protect land condition and water quality.

The location, type and area of all dryland salinity management works in the Catchment should be recorded on a spatial information system to enable the co-ordination of dryland salinity management works (see Recommendation 2).

Recommendation 19: The DNR develop systems in consultation with the SCA for recording the location, nature and extent of actual cases of soil erosion and land salinity in the Catchment.

Recommendation 20: Programs addressing soil erosion and salinity in the Catchment target areas with identified risk, and integrate with other programs for riparian and vegetation management where possible.

Map 4.5 – Salinity risk and observed salinity in the Sydney Drinking Water Catchment

Land Condition 79

Actions and Response

Response to issue The two primary responses to protecting and improving land condition are to:

i) ensure new activities in the Catchment incorporate appropriate measures to prevent pollution, contamination and land degradation

ii) where technically and economically feasible, to repair lands already degraded.

This section outlines the major actions aimed at protecting and improving land condition in the Catchment. These include:

• general programs to reduce land degradation from different land uses

• programs to reduce land degradation from identified high risk industries

• programs to manage areas of potential soil erosion

• programs to manage areas of high salinity risk.

General programs to reduce land degradation from different land uses

Land use planning

The regulation of land-use type and location within the Catchment is primarily guided by the Environmental Planning and Assessment Act 1979 (EP&A Act). Local Councils also have a range of powers under the Local Government Act 1993 and the POEO Act that can be used to manage specific land use issues. Land use planing instruments that cover the control and management of land uses include:

• State Environmental Planning Policy 58 (SEPP 58) – The purpose of SEPP 58 is to ensure that new development in the Catchment does not impact on water quality. The SEPP provides a concurrence or notification role for the Chief Executive of the SCA for new development specified in Schedules 1 and 2 of the SEPP in certain locations within the Catchment. The SEPP requires consent authorities to consider whether the proposed development will have a neutral or beneficial effect on water quality and whether water quality management practices will be sustainable in the long term. SEPP 58 was introduced as an interim measure and is to be replaced by a Regional Environmental Plan (REP) when gazetted.

• Regional Environmental Plan (REP) – The Sydney Water Catchment Management Act 1998 requires a REP to be prepared as part of a broader regional plan. A draft regional plan has been prepared and was publicly exhibited from March to July 2004. The exhibited draft regional plan contains:

• statutory components including the REP under Part 3 of the EP& A Act, and a s117 Ministerial direction requiring local councils to review Local Environmental Plans after SCA has completed Strategic Land and Water Capability Assessments (SLWCA) of the capability of land and water to support land use type and intensity.

• guidelines to support the implementation of the regional plan including:

o neutral or beneficial effect assessment guidelines

o guidelines for rectification action planning

o a framework for applying SLWCAs.

• Development Assessment Register (DAR) – was developed to manage the development proposals received by the SCA. The DAR is an interactive system that links applications with spatial information and helps SCA to assess the possible impact of a particular development on water quality.

Audit of the Sydney Drinking Water Catchment 2005 80

• Local Environmental Plans (LEP) – All councils within the Catchment have LEPs that specify the land use zones and specific controls on land. LEPs must be consistent with relevant REPs or SEPPs.

o SEPP 58 also requires councils to consider whether development proposals requiring consent under the LEP have a neutral or beneficial effect on water quality.

Other programs

• Rectification Action Plans (RAPs) – The Sydney Water Catchment Management Act 1998 also requires the development of rectification action plans to rectify existing land uses that do not have a neutral or beneficial effect on the quality of water, within certain time limits after the gazettal of the REP. RAPs must be prepared for each sub-catchment and will be informed by Catchment Action Plans prepared by Catchment Management Authorities. Development of RAPs has been postponed due to the delay in exhibiting the REP. SCA is developing a RAP Decision Support System to rate and prioritise pollution sources and identify appropriate rectification options. This Decision Support System will be completed by the end of 2005.

• Strategic Land and Water Capability Assessments (SLWCAs) – The SCA is refining methodology for the identification of land uses that are either currently impacting on water quality or have the potential to affect water quality in the future. The SLWCAs will serve as a basis for RAPs to remedy existing activities in problem areas. The SLWCAs which were drafted in the 2003 Audit period (Wollondilly River (priority), Upper Wollondilly River (priority), Mulwaree River (priority), Wingecarribee River (priority) and Nattai Rivers sub-catchments) have been completed. The cost of the SLWCA project for 2003–04 was $250,000.

• Current Recommended Management Practices (CRPs) – This SCA program is designed to encourage the use of locally tried and tested practices and best management practices developed by experts. The CRPs will be endorsed by the SCA. Examples of potential current recommended practices include Managing Urban Stormwater: Soils and construction (Landcom, 2004), Managing Urban Stormwater: Treatment Techniques (EPA, 1997) and Urban Stormwater, Best Environmental Management Guidelines (CSIRO, 1999).

• Catchment Action Plans – The Catchment Management Authorities develop Catchment Action Plans that consolidate and build on the existing native vegetation plans and Catchment Blueprints.

• Healthy Catchments Program (HCP) – has seven strategies including a land management and rural lands strategy, and uses tools such as grants and assistance schemes, education programs and regulation to improve land management practices. The Healthy Catchments Program will be the primary SCA mechanism for implementing actions identified under RAPs.

• The Southern Rivers CMA has developed a Sustainable land use program. This program includes research & development, land use assessment, implementation of a range of locally applicable incentive schemes to encourage changed land management practices, establishment of demonstration sites, and provision of technical advice/extension services.

• The Sydney Drinking Water Catchment Management (Environment Protection) Regulation 2001. This enables the SCA to exercise certain regulatory functions under the POEO Act with regard to non-scheduled premises and activities. During 2003–04, 8 Clean-up Notices, 4 notices requiring information and 7 PINs were issued in the relation to matters in the Catchment.

Rural lands

• A number of new guidelines have been developed by the NSW DPI for the sustainable management of agricultural developments during the 2005 Audit period:

o Buffers planning for sustainable agriculture

o NSW Meat Chicken Farming Guidelines

o Guidelines for the development of Controlled Environment Horticulture: Planning Greenhouse and Hydroponic Horticulture in NSW

o Managing Pastures After Drought

Land Condition 81

o Managing Native Pastures for Agriculture and Conservation (with Hawkesbury–Nepean CMA and NHT)

o The Grazier’s Guide to Pastures

o Best Practice Management Guidelines for Graziers on the Tablelands of NSW (with the Hawkesbury–Nepean CMA and NHT).

• The Hawkesbury–Nepean CMA has also identified as a priority the provision of best practice grazing management for agriculture, biodiversity and water quality within the Warragamba Catchment.

Special Areas

Strict access control is enforced over the Special Areas to protect water quality and ecology. The SCA spent $160,000 to improve access controls along the perimeters of SCA lands. Using these measures together with regular catchment patrols, the SCA issued 79 Penalty Infringement Notices and 69 warning letters in 2003–04 for breaches of the Sydney Water Catchment Management Regulation 2001.

Programs for high risk industries

Sites licensed under the POEO Act

The EPA regulates major point sources using licences issued under the POEO Act. The licences include comprehensive requirements for pollution control, monitoring and reporting. The EPA negotiates Pollution Reduction Programs (PRPs) with licensees to address environmental issues and risks, and imposes the programs as formal licence requirements. Relevant PRPs issued during the 2005 Audit period are summarised in Table 4.5.

Table 4.5 – Pollution reduction programs for mines, quarries and miscellaneous activities licensed under the POEO Act for the 2005 Audit period

Licensed activities PRP Description

Appin Colliery PRP4

PRP6

PRP7

PRP8

PRP9

Effluent Treatment Management Plan

Report options to minimise coal tracking from premises

Monitoring trial of water receiving mine water discharges

Filtering pre-treatment of minewaters

Provide report on design ecological assessment for impacts on ecology

Berrima Feedmill PRP3 Stormwater Management Improvement Works

Goulburn Wool Scour PRP2

PRP3

PRP4

Evaporation Tube Technology

Environmental Management Plan for Evaporation Technology

Rehabilitation Plan of Yarra and Goulburn Irrigation areas to rehabilitate soils to comply

Marulan Pit PRP5 Groundwater monitoring program

Marulan Quarry (Lacey’s Pit) PRP5 Groundwater monitoring program

Rocla Concrete Sleepers PRP2 Investigate options to manage stormwater and submit report, timeframe for implementation

Southern Limestone P/L PRP3 PRP1 not adequately implemented so new PRP created: Stormwater Management Plan

Southern Meats PRP1

PRP3

Investigate and implement options to reuse and recycle brine to eliminate need for disposal

Three stage program investigation works to ensure effluent irrigation is sustainable

Warragamba Waste Management

PRP1

PRP2

Comprehensive investigation major environmental issues as premises

2nd instalment of PRPs design to address long term environmental issues at premises

Woodlawn Mine PRP4

PRP5

Groundwater monitoring confirmation survey and replacement groundwater monitoring bores

Calibration of water balance model compare volume water in ED3 with modelled predictions

Source: DEC 2005

Audit of the Sydney Drinking Water Catchment 2005 82

SCA’s Catchment Inspection Plan

The SCA has developed a Catchment Inspection Plan that provides an inspection schedule based on an initial risk assessment of industry types (EASI project) and the Water Quality Risk Management Framework to identify locations in which particular pollutants pose risks to water quality. The SCA has set specific timeframes for assessing individual sites based on an initial risk assessment, and has also set timeframes for follow up inspections of sites based on relative risk.

Solid waste management

Goulburn Mulwaree Council has carried out significant upgrades at the Goulburn Waste Management Centre to improve environmental performance, waste diversion measures, and improve ease of use by customers.

Derelict mines

The Derelict Mine Committee sets priorities for the Derelict Mine Program which is aimed at reducing the safety and environmental risks posed by derelict mines. The program is administered by the NSW DPI and involves consultation with organisations such as DEC and the NSW Minerals Council. The NSW Government allocated approximately $1.6 million to the Derelict Mines Program for 2003–04. Under this program, investigations have been carried out into the rehabilitation of the derelict Oakdale colliery pit top during the 2005 Audit period, and works have continued at Yerranderie Silver Field.

During the 2005 Audit period, the NSW DPI was granted $2.8 million through the Environmental Trust to undertake further work on four major derelict mine sites in NSW, including the Yerranderie Silver Mines in the Catchment. Works undertaken at Yerranderie included the investigation into acid mine drainage sources, heritage issues and fencing to reduce safety hazards. Water quality monitoring equipment was installed at three sites on the Tonalli River to monitor any runoff from Yerranderie.

The SCA also has a program aimed at derelict mine rehabilitation in Special Areas. This includes Yerranderie, Nattai/Oakdale, Nattai Bulli Valley, Brimstone Mines and Wollondilly Washery (Figure 4.5 and 4.6).

Figure 4.5 – Wollondilly Washery detention Pond, October 2005

Figure 4.6 – Wollondilly Washery rehabilitation, October 2005

Land Condition 83

Extractive industry

DEC conducted a joint inspections program with SCA officers in 2003–04 to assess mining premises in the Catchment that were initially considered by the SCA to be potential risks. A brief summary of the issues or environmental risks identified at each site and DEC actions on each site are summarised in Table 4.6.

Subsidence management

To address the issue of river bed cracking due to mine subsidence any mining activity that may cause subsidence must prepare a Subsidence Management Plan in line with a new approval process under the Mining Act 1992. These plans must account for all possible impacts of potential subsidence to provide adequate protection for the natural and built environments. A Subsidence Management Plan Review Committee has been established to review draft subsidence plans, advise on conditions of approval, and participate in ongoing monitoring of subsidence management.

Extensive preventative measures and monitoring systems have been installed to protect SCA infrastructure from underground mining in the Appin area either beneath or adjacent to parts of the SCA Upper Canal (SCA, 2004a).

Audit of the Sydney Drinking Water Catchment 2005 84

Table 4.6 – Summary of issues or environmental risk and DEC actions at mining and extractive industry premises

Site Name Summary of Environmental Risk and DEC Action Berrima Colliery

Primary issue is stormwater, including a need for improved bunding for oil and fuel storage, changes in stormwater systems to enable maintenance more readily, and need to install improved on-site sewage management. DEC is satisfied that the licensee is progressively improving stormwater management, and will continue to monitor progress through regular site inspections. The licensee has advised DEC that it intends to install a new on-site sewage management system, and will seek necessary approvals from Council and SCA.

Wallerwang Colliery

Site has not been mined for over a decade. The coal, wastes and chitter on the premises are the source of acid drainage, but this appears to be managed adequately through a leachate dam and limestone bed which has been installed to correct pH. Water quality monitoring downstream of the leachate dam indicates there is minimal impact on water quality from acid mine drainage. DEC is negotiating a Pollution Reduction Program to require the rehabilitation of the site.

Canyon Colliery (Coalpac)

The main issue for DEC is the continuing discharge of groundwater from the adit. The options for remediation of the site are complicated by access limitations to the adit and the sensitive environment. Based on a report from Coalpac, DEC considers that the environmental impacts of accessing the adit poses a greater overall environmental risk than the current discharge from the adit, and no certainty that the remediation of the adit would be successful in the longer term.

Ivanhoe Colliery

No inspection undertaken as there is no discharge point to the Catchment. Mining and the washery have ceased operating and the pit top has been cleaned up. Uncontaminated stormwater has been diverted away from contamination. The licensee is preparing a site rehabilitation plan. DEC will review the rehabilitation plan and follow up on its implementation.

Springvale Colliery

The discharge from the site has elevated sulphate levels, and DEC is keen to address this matter. The licensee is proposing to pipe discharge water to Mt Piper and Wallerawang Power Stations, which will result in no direct discharge to the Catchment. DEC will continue to be involved in the review of this proposal.

Wollondilly Washery

Rehabilitation works are being undertaken, although much more rehabilitation needs to be undertaken to address potential water quality impacts. DEC will follow-up on rehabilitation progress.

Marulan Quarry

The site is a net user of stormwater and therefore does not generally discharge from site. Water quality in on-site ponds is good, with TSS <20mg/L and pH about 8. Quarry has good housekeeping practices. No immediate DEC follow up required.

Braidwood Sand Pit

No water discharges from site. No significant environmental risks identified. No further DEC action required.

Bunnygalore Quarry

Small quarry. Runoff is directed to a sedimentation pond which appears adequate. No significant water issues identified. Rehabilitation plan required by council development consent, and is being implemented. No further DEC action required.

Welby Quarry

Small to medium sized sandstone quarry. Water management system is adequately sized. No significant storm water issues identified. DEC to follow up some minor operational issues.

Exeter Quarry

Rehabilitation being undertaken. Extraction has almost ceased. Stormwater system is operating adequately. Fuel and liquid storage needs attention. DEC to undertake follow-up inspection.

Soapy Flat Sand Pit

Complicated water management arrangements but operators appear to be managing the site in a satisfactory manner. No further DEC action required.

Penrose Sand Quarry

Water management improvements have been achieved at this site over the past several years. The licensee has a proactive approach to environmental concerns. DEC will undertake follow-up inspection to monitor improvements.

Source: DEC 2005

Land Condition 85

Programs to manage soil erosion

Catchment Protection Scheme – The Catchment Protection Scheme is administered by the CMAs, and is a joint initiative with landholders and the SCA. The Scheme provides financial assistance and professional advice to landholders trying to manage moderate to severe erosion on their properties. For on-ground work in the Hawkesbury–Nepean CMA during 2004–05 see section 4.3 and 4.4. The Hawkesbury–Nepean CMA expenditure has increased from $172,000 in 2004–05 to $635,000 per year over the next audit period. The Hawkesbury–Nepean CMA also contributes approx $550,000 in kind each year to such works.

• In 2003 the SCA carried out a study in the Braidwood lands using aerial photography to assess areas that were considered erodable based on colour, morphology and location. Approximately 185 hectares, or less than one percent of the SCA Braidwood lands is subject to erosion.

• The SCA mapped stream bank and stream bed erosion on Piper’s Flat Creek (20 km) in the Upper Coxs River (priority) sub-catchment and Cullenbenbong Creek (7 km) within the Mid Coxs River (priority) subcatchment.

• The NSW DPI is investigating the use of compost for erosion control. This is being trailed in Bungonia Creek sub-catchment.

• The NSW DPI produced a fact sheet in January 2005 on ‘Maintaining groundcover to reduce erosion and sustain production’. This fact sheet aims to inform land owners on the percentage of groundcover required to minimise runoff and soil erosion.

• The CSIRO is developing methods for estimating soil erosion rates, to assist in the assessment and management of soil erosion.

Programs to manage salinity

There is a National Dryland Salinity program and a NSW Salinity Strategy both aimed at improving the availability of information about salinity and its management.

The NSW DPI is implementing a number of specific salinity programs in NSW, including training programs, integrating research and assisting landholders to improve the productivity of existing saline land.

The Hawkesbury–Nepean CMA coordinates and facilitates salinity management in Western Sydney.

Gaps in the response

The REP includes components such as the integration of the SLWCA process into LEPs which will assist in preventing or managing increased pressures from new development on land condition and water quality. The gazettal of the REP is therefore an important strategic response that needs to be finalised.

Many of the programs for erosion and salinity management appear to be broad policy, frameworks or guidance. Active on-ground response programs need to be further developed and implemented in high risk erosion and salinity areas in the Catchment and in locations subject to actual erosion and salinity.

Ecosystem Health 87

Chapter 5 Ecosystem Health

Key Points

Indicator Status of Indicator

5.1 Ecosystem water quality Since the 2003 Audit period, the number of locations exceeding ANZECC water quality guidelines has increased for physical parameters such as conductivity, remained high for nutrient parameters and reduced for toxicants.

5.2 Macroinvertebrates There are less sampled locations with similar to reference ratings compared with the 2003 Audit period. Macroinvertebrate assemblages at 32% of the sampled locations in the Catchment were found to be significantly impaired and 5% of all sampled locations had a severely impaired rating.

5.3 Fish Monitoring of fish communities in the Catchment is still needed as a potentially useful indicator of ecosystem health.

5.4 Riparian vegetation Riparian zones outside the Special Areas are likely to be under variable pressure due to little to no standing vegetation cover, stock access, and the presence of exotic species. Change in condition of vegetation in the riparian zone is not able to be determined.

5.5 Native vegetation Native vegetation covers approximately 50% of the Catchment.

Approved land clearance substantially decreased over the 2005 Audit period.

Healthy and intact natural ecosystems play a crucial role in maintaining water quality as they provide processes that help purify water, and mitigate the effects of drought and flood. An overall picture of the ecological health of a catchment can be achieved using tools such as water quality, habitat descriptions, biological monitoring and flow characteristics (Qld DNRM 2001). Ecosystem health assessment has become more ecologically based in recent years with biological measures such as ecosystem structure and species diversity having been added to traditional physico-chemical water quality analysis to provide a more comprehensive picture of the condition or catchment health (Qld DNRM 2001). This audit examines:

• traditional ecosystem water quality parameters

• aquatic communities, namely macroinvertebrate and fish communities

• terrestrial ecosystems of riparian and native vegetation communities.

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Pressures in the Catchment Sydney’s drinking water supply is managed using a multi-barrier approach to control risks to water quality, including catchment management, storage management, delivery system management and treatment systems (SCA, WQRMF, 2005). Healthy natural systems in the Catchment and around storages contribute to this multi-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. 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 multi-barrier approach to protecting water quality as they provide ecosystems in reasonably good condition that buffer against nutrients and other pollutants 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 breaks 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.

Ecosystem health is affected by a number of natural and human induced pressures. Natural pressure on ecosystem health and condition include fire, flood and drought. The primary human induced pressures on ecosystem health in the Catchment are land use change (Chapter 4), water demand and management (Chapter 3), and land management (Chapter 4). These human induced pressures can directly disturb or destroy ecosystems, as well as indirectly affect ecosystem processes through impacts on water quality, flow regimes, and biodiversity.

Aquatic ecosystems are particularly important as an indicator of a range of pressures resulting from water and land based activities in the Catchment. Aquatic ecosystem health is a function of many factors including water quality, community structure and diversity (for example, macroinvertebrates and fish), and the extent and condition of riparian and native vegetation in the Catchment. All these factors contribute to the ability of aquatic ecosystems to support and maintain a balanced, integrated, adaptive biological system (Milligan et al. 2002).

Chemical, nutrient and cold water pollution are some of the possible threats to aquatic ecosystems caused by human practices and land uses. Clearing of native vegetation and riparian zones can also affect land condition, biodiversity and runoff volumes which ultimately impact water quality and aquatic ecosystem processes. Riparian vegetation is particularly crucial for water quality and aquatic ecosystem processes, and also provides habitat for terrestrial fauna. Managing native vegetation clearing, particularly in riparian areas, is therefore important to maintaining ecosystem health.

The presence of exotic fauna is also a pressure on ecosystem health in the Catchment, with exotic species causing physical damage to soil and vegetation, and preying on native species and disrupting natural ecosystem processes. Exotic plant species can also affect ecological processes in vegetation communities.

Ecosystem Health 89

State of the Catchment

5.1 Ecosystem water quality

Background

Healthy ecosystems generate and maintain good water quality. This audit examines 12 water quality parameters that signal whether the state and pressures in the Catchment are impacting on water quality required to maintain aquatic ecosystems. These parameters were assessed against the guidelines 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 (2000).

The auditors used the same methods as the 2003 Audit to provide a visual presentation of ecosystem water quality across the Catchment (see Map 5.1). The 12 parameters were combined into the following four groups:

• Physical – Turbidity (NTU), pH and Conductivity (µS/cm)

• Toxicants – Total Aluminium (Al) (mg/L) and Total Iron (Fe) (mg/L)

• Nutrients – Total nitrogen (µg/L), Total phosphorus (µg/L), Oxidised nitrogen (µg/L), Ammonia (µg/L) and Filtered phosphorus (µg/L)

• Chlorophyll–a (µg/L) and Dissolved Oxygen (%).

The parameter with the highest level of exceedence within a group was then used to rate that group. The groups were rated as:

• ‘Very Poor’ when one or more parameters exceeded the guidelines in more than 75% of samples

• ‘Poor’ when one or more parameters exceeded the guidelines in 50 – 75% of samples

• ‘Fair’ when one or more parameters exceeded the guidelines in 25 – 50% of samples

• ‘Good’ when less than 25% of samples for all parameters exceeded the guidelines.

Findings

The percentage of locations that exceeded the ANZECC guidelines for aquatic ecosystem protection was lower in the 2005 Audit period than in the 2003 Audit period for 7 out of the 12 parameters tested (Figure 5.1). The parameters that had an increase in percentage of locations where there was an exceedence of the guidelines during the 2005 Audit period were turbidity, conductivity, oxidised nitrogen and ammonia (Figure 5.1). Conductivity had the largest increase in the percentage of locations exceeding guidelines (from 17% in the 2003 Audit period to 67.4% in the 2005 Audit period). Total Iron had the greatest decrease in percentage of locations exceeding guidelines (from 54% in the 2003 Audit period to 26% in the 2005 Audit period).

Audit of the Sydney Drinking Water Catchment 2005 90

Figure 5.1 – Percentage of locations that exceeded the ANZECC and ARMCANZ 2000 guidelines for ecosystem health for the 2001, 2003 and 2005 Audit periods

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Lake Yarunga (L*) was the only location that rated very poor across all four groups for the 2005 Audit period. During the 2003 Audit period, Lake Yarunga (L*) rated very poor in three water quality groups.

Wingecarribee River (CH*) had three water quality groups rated very poor for both the 2003 and 2005 Audit periods. Gillamatong Creek (CV*), Wollondilly River (CI*), and Werriberri Creek (CM*) rated very poor in three water quality groups during the 2003 Audit period, and have all improved in at least two water quality groups during the 2005 Audit period.

During the 2003 Audit period Gibbergunyah Creek (CD*) and Mulwaree River were rated as very poor in all four water quality groups. Gibbergunyah Creek (CD*) improved in Physical parameters, but still had very poor ratings for Toxicants, Nutrients and Chlorophyll-a and Dissolved Oxygen. Mulwaree River was not re-sampled during the 2005 Audit period.

The majority of the high exceedences of ANZECC guidelines related to the Nutrient parameters during both the 2003 and 2005 Audit periods. The percentage of locations exceeding ANZECC guidelines for Physical parameters in catchments, lakes and reservoirs increased from 33% in the 2003 Audit period to 78% in the 2005 Audit period. The percentage of locations exceeding ANZECC toxicant guideline levels decreased from 70% during the 2003 Audit period to 48% in the 2005 Audit period, while the number of locations exceeding nutrient guideline levels remained relatively constant and high at 93% (Appendix E Table 2 and 3).

* See Map 5.1 for locations of sampling sites and Appendix E Table 5 for explanation of codes.

Map 5.1 – Water quality monitoring sites showing the 4 parameter groups and percentage compliance in the Sydney Drinking Water Catchment

Ecosystem Health 91

For Physical parameters, there was a 66% increase in the number of locations exceeding ANZECC guidelines compared to the 2003 Audit period, 9% of locations improved and 25% of locations experienced no change (Appendix E Table 4).

For Toxicant parameters, 48% of locations experienced no change from the 2003 Audit period, 11% of locations increased in the percentage of samples exceeding ANZECC guidelines, and 41% of locations improved (Appendix E Table 4).

For Nutrient parameters, 64% of locations experienced no change from the 2003 Audit period, 32% of locations had an increase in the percentage of samples exceeding ANZECC guidelines, and 5% of locations improved from the 2003 Audit period (Appendix E Table 4).

For Chlorophyll and Dissolved Oxygen, 66% of locations experienced no change in the frequency of exceedance of ANZECC guidelines since the 2003 Audit period, 18% of locations had an increase in the percentage of exeedences of guidelines, and 16% of locations had a reduction in the number of exceedances of ANZECC guidelines (Appendix E Table 4).

Pesticides are monitored at 22 locations in the Catchment. ANZECC (2000) specifies an ecosystem health guideline value for some, but not all pesticides. This audit has adopted an interim benchmark that was established by DEC using available data on lethal and effect concentrations (LC50 and EC50) on macroinvertebrates, where there is no ANZECC (2000) guideline. In the 2005 Audit period all pesticide levels were below the relevant ANZECC guidelines and interim DEC benchmarks.

Implication

Water quality exceeded ANZECC water quality guidelines for ecosystem health over the 2005 Audit period for 50% of the water quality parameters tested at over 40% of locations. Since the 2003 Audit period, the percentage of locations in exeedence of nutrient parameters has remained high, the number of locations at which physical parameters were exceeded has increased, and exceedence of Chlorophyll-a and Dissolved Oxygen has changed little. However, the percentage of locations at which toxicant parameters exceeded ANZECC guidelines for ecosystem health has decreased over the 2005 Audit period. While the auditor is concerned by the increased locations exceeding ANZECC guidelines for nutrients (93% of locations) and the substantial increase in locations exceeding guidelines for conductivity, it is acknowledged that low flow from current drought conditions may be influencing these results.

The majority of high exceedences were in the Nutrients group in both the 2003 and 2005 Audit periods. Oxidised Nitrogen exceeded guidelines in 76–98% of locations between 1999 and 2005. The number of locations at which ammonia levels have exceeded guidelines has continually increased from 39% between 1999 and 2001, to 83% of locations during the 2005 Audit period. High levels of nutrients in the water column may be caused by a combination of decreased flushing and increased residence times resulting from drought conditions, diffuse nutrient sources from catchment land use and run-off (rural and urban), and point sources of pollution including sewage treatment plant discharge and sewage overflow events. High nutrient levels are associated with eutrophication and nuisance growth of aquatic plants and algae, and are therefore a concern for both ecosystem health and bulk water supply.

High exceedences in the Physical parameters (predominantly conductivity) and an increase in the number of locations exceeding the ANZECC guidelines could also be related to low flow resulting from drought because groundwater contribution to surface flow may have more influence on water quality than under average flow conditions. While an appropriate concentration of salts (measured by conductivity) is vital for aquatic plants and animals, salinity beyond the normal range can cause stress or death of aquatic organisms. Highly saline conditions can also affect the availability of nutrients to plant roots, and therefore disturb aquatic plant growth and aquatic ecosystems.

The continued exceedence of Dissolved Oxygen guideline values in over 55% of locations from the 2003 Audit and the 2005 Audit may be having a direct impact on aquatic biota. In addition, low Dissolved Oxygen levels can also cause changes in redox conditions, aiding the release of phosphorus from sediments which can increase nutrient levels in water.

Audit of the Sydney Drinking Water Catchment 2005 92

The low pesticide levels observed in the Catchment during the 2005 Audit period may be related to drought conditions, and improved pesticide management practices.

The SCA’s water quality monitoring program is largely restricted to the north east region of the Catchment. There are several sub-catchments with few or no monitoring sites where water quality could be expected to be under stress (see Future Directions below). A number of the priority sub-catchments have only one or two water quality monitoring sites, and the priority sub-catchments of Mulwaree River, Upper Wollondilly River and Upper Coxs River have no water quality monitoring sites. The current SCA water quality monitoring program does not give a comprehensive picture of water quality throughout the Catchment.

Future directions

Routine ecosystem water quality monitoring is currently undertaken at 17 of 28 sub-catchments. Some of the sub-catchments with few or no routine water quality monitoring have been identified as areas under environmental stress by other indicators or as priority sub-catchments by the SCA. These sub-catchments include the Upper Coxs River (priority), Mid Coxs River (priority), Upper Wollondilly (priority), Mulwaree River (priority) and Nerrimunga Creek sub-catchments.

The integration of monitoring programs by sampling for multiple indicators at the same location would also be beneficial to understanding the reason for Catchment condition, and would provide more confidence in selection of action and response programs. See Recommendation 3.

Recommendation 21: The SCA review its water quality monitoring program to ensure that appropriate ecosystem water quality monitoring is undertaken in all sub-catchments.

5.2 Macroinvertebrates

Background

‘River health’ is a concept that goes beyond suitability of water for particular uses and integrates a range of ecosystem values and functions. Macroinvertebrate assemblages integrate many aspects of the ‘health’ of streams and rivers, complementing the more traditional assessments of water quality.

Macroinvertebrates are typically visible with the naked eye and exist in a variety of habitats in streams, lakes and wetlands. Of all biological communities used to assess health, macroinvertebrate assemblages are most widely used, as they are abundant and diverse, sensitive to changes in water quality, flow regime and habitat conditions and they allow detection of impacts some time after the impact has occurred (Qld DNRM, 2001). Additionally, there is reasonably good taxonomic knowledge of freshwater macroinvertebrates, and they are relatively easy to collect.

The AusRivAS system is widely practised and supported for use in environmental audits by independent studies (Cullen & Cottingham, 1999) and national water monitoring programs. The AusRivAS sampling protocols were developed as part of the National River Health Program’s Australia-wide Assessment of River Health. Since 1994, more than 1500 reference sites across Australia have been sampled to build predictive models to interpret field sampling results. The AusRivAS system generates river health assessments by predicting the macroinvertebrates that would be present (expected) and compares this with the macroinvertebrates collected (observed) to create an index of health. The lower the observed/expected value, the more impaired the macroinvertebrate assemblage. The SCA is required by its Operating Licence to undertake annual macroinvertebrate sampling during spring. The Spring 2005 AusRivAs data was unavailable for this audit due to the spring sampling.

This audit presents the 2001 to 2004 Spring AusRivAS scores at 73 sampling location.

Ecosystem Health 93

Findings

During Spring 2004, the macroinvertebrate assemblages at 33% of the sampled locations in the Catchment were significantly impaired, and 6% of all sampled locations had severely impaired ratings. On average, between the 2001 Spring sampling and the 2004 Spring sampling:

• locations with a similar to reference rating decreased

• locations with a significantly impaired rating increased

• locations severely impaired and locations with a richer than reference had little to no change.

Jacqua Creek at Lumley Rd (NZ*) received an AusRivAS health rating of severely impaired during Spring 2003. Three locations had an AusRivAS health rating of severely impaired from the 2004 Spring sampling. The severely impaired locations during Spring 2004 were Werriberri Creek at The Oaks (OE*), Woronora River at The Neddles (MT*), and Tarlo River at Tarlo (MB*). Tarlo River at Tarlo (MB*) also had a decreased health rating in the 2003 Audit period (Map 5.2).

The AusRivAS health rating decreased at the following nine sites between Spring 2001 and Spring 2004: Shoalhaven River at Farrington crossing and at Hillview (NG* and MQ*), Jacqua Creek at Lumley Road (NZ*), Mulloon Creek at Tawarri (OK*), Tarlo River at Tarlo (MB*), Waratah Rivulet at Flat Rock crossing (OJ*), Werriberri Ck at Serenity Park and The Oaks (MV* and OE*) and Wollondilly River at Baw Baw Bridge (OO*) (Map 5.2).

Richer than reference ratings between Spring 2001 and Spring 2004 were recorded at Jerrabuttgulla Creek at Warragandra (NB*), Corang River at Meangora (MN*), Mongarlowe River at Monga (OI*), Shoalhaven River at Yarra Glen (MY*), Kowmung River at Kowmung fire trail (NE*), Coxs River at Kelpie Point (MC*) and Wollondilly River at Goonagulla (NK*) (Map 5.2).

The AusRivAS health rating improved from Spring 2001 to Spring 2004 at the following six sites: Woodford Creek at Woodford Dam (NR*), Currembene Creek at Krawaree Rd crossing (OL*), Little River at fire trail and Six Foot Track (MX* and OC*), and Coxs River at Lidsdale and McKanes Bridge (OV* and NP*) (Map 5.2).

The AusRivAS health rating remained unchanged at the other 19 sampling sites between Spring 2001 and Spring 2004. A number of locations with a health rating of significantly and severely impaired macroinvertebrate assemblages in Spring 2004 also exceeded ANZECC (2000) guidelines in 3 or 4 groups of physico-chemical water quality (See Maps 5.1 and 5.2). These locations include Gillamatong Creek at Braidwood (CV-MS) and Shoalhaven River at Hillview (CU-MQ). Shoalhaven River at Hillview (MQ) has declined in AusRivAs health, from similar to reference in Spring 2001and Spring 2002 to significantly impaired in Spring 2003 and Spring 2004, and also had a decline in water quality compared to the 2003 Audit period for toxicant parameters (see Section 5.1 and Map 5.1).

Implication

In general, the AusRivAs macroinvertebrate health ratings have declined since 2001. While this suggests overall diminishing health, it is unclear whether this is due to deteriorating water quality or drought conditions.

During Spring 2004, the macroinvertebrate assemblages at 33% of the sampled locations in the Catchment were significantly impaired, and 6% of all sampled locations had severely impaired ratings. The sites with an AusRivAS health rating of severely impaired in Spring 2004 are in the Wollondilly River (priority), Werriberri Creek (priority) and Woronora River sub-catchments. The sampling locations in the Wollondilly River (MB) and Werriberri Creek (OE) sub-catchments are located near pasture land (see Map 4.1 for land use locations), although the reason for the macroinvertebrate rating was not investigated.

* See Map 5.2 for macroinvertebrate sampling locations and Appendix E Table 5 for explanation of codes.

Audit of the Sydney Drinking Water Catchment 2005 94

Sites with a richer than reference rating can occur because of either a naturally high biodiversity, or an impact such as mild nutrient enrichment (Barmuta et al. 2002). Seven sub-catchments had a richer than reference rating between Spring 2001 and Spring 2004. All richer than reference locations from the Spring 2004 sampling were adjacent or close to pasture land (see Map 4.1 for land use), although there is no water quality monitoring at these locations to assist with the interpretation. Follow up macroinvertebrate monitoring should be considered at all these locations to determine whether the AusRivAS health rating results from natural processes or human induced impacts.

The spatial coverage of macroinvertebrate monitoring across the Catchment is generally better than for the water quality monitoring assessed in Section 5.1, as more sub-catchments are monitored. The current SCA macroinvertebrate sampling design requires two ‘core’ or fixed, long-term monitoring sites per sub-catchment, and one ‘roaming’ site which changes from year to year. This is not reflected in the data provided by the SCA for the audit as only 53 sites were sampled for Spring 2003 and Spring 2004. The inclusion of annual roaming sampling sites allows a wider area of each sub-catchment to be monitored over time. However, it can also result in locations where impacts on macroinvertebrate are detected on one sampling year not being monitored in subsequent years. For example, Wollondilly River at Murrays Flat (MH) had a significantly impaired macroinvertebrate rating in Spring 2002, but was not sampled in subsequent years. Consequently, it is not possible to determine whether the results were a short term, natural occurrence or whether there is a continued impact that needs to be investigated and addressed to ensure ecosystem health in that location. It is suggested that consideration also be given to follow-up sampling at sites with high macroinvertebrate impairment ratings to aid in longer term analysis. This will provide greater confidence in management responses to macroinvertebrate health ratings.

In addition to follow-up macroinvertebrate monitoring, the integration of macroinvertebrate and water quality monitoring in the Catchment would be beneficial to provide capacity for a more comprehensive assessment of Catchment condition, and interpretation of results. Such integration may also enable more focussed management responses to identified changes in the condition of macroinvertebrate assemblages. See Recommendation 3 and Recommendation 22 below.

Recommendation 22: The SCA review its macroinvertebrate monitoring program to ensure that monitoring is further integrated with water quality monitoring (i.e. the sites are monitored for both macroinvertebrates and water quality parameters).

Recommendation 23: The SCA consider follow-up monitoring at macroinvertebrate monitoring locations that have significantly impaired or severely impaired AusRivAS ratings.

5.3 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.

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).

Map 5.2 – Macroinvertebrate AusRivAS health rating for Spring 2001 – Spring 2004 in the Sydney Drinking Water Catchment

Ecosystem Health 95

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 (Astles et al. 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 (Thorncraft and Harris, 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.

There is only limited new data on fish communities in the Catchment since the 2003 Audit Report. However, this indicator remains relevant as a measure of ecosystem health which should be retained for future audits, 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).

Given the limited additional data, this audit examines:

• numbers of native and exotic fish species, for limited locations where data is available

• removal of barriers to fish migration.

Findings

There are three sets of localised data that update information presented in the 2003 Audit Report. These data sets are a:

i) NSW Department of Primary Industries (NSW DPI) survey for the presence of Macquarie Perch (Macquaria australasica) in April and May 2005

ii) NSW DPI research of Carp (Cyprinus carpio) communities, with sampling in the Catchment undertaken at Fitzroy Falls reservoir, Lake Alexandra at Mittagong and at Tallow Dam

iii) Fish survey in the Coxs River undertaken by Delta Electricity in accordance with its Water Management Licence, to assess the impacts of new flow regimes.

The Macquarie Perch (M. australasica) is listed as a vulnerable species under the Fisheries Management Act 1994 and has been found in the Mongarlowe River, Warragamba, Nepean, Avon, Cordeaux and Cataract Dams and in the Lower Nepean and Cataract Rivers below the storages. The NSW DPI surveyed for the presence of Macquarie Perch at seven locations in the Catchment during April and May 2005. Macquarie Perch were present at Coxs River at Kelpie Point, Kowmung River at Cedar Ford and Little River.

Carp (C. carpio) is a noxious species in a number of Australian states. The NSW DPI is currently undertaking research into the comparative age, sex and genetic analysis of carp populations. Carp were present at all sites sampled by the NSW DPI in the Catchment. These sites were at Fitzroy Falls Reservoir, Tallowa Dam in the Kangaroo River (priority) sub-catchment, and at Lake Alexandra in the Nattai River sub-catchment.

Delta Electricity operates two power stations, Mount Piper and Wallerawang, in the Upper Coxs River (priority) sub-catchment. Delta Electricity undertakes a range of monitoring in accordance with requirements of its Water Management Licence including water quality, biological and geomorphic parameters to assess ecosystems responses in the Coxs River to environmental flow releases from Lyell Reservoir. The biological monitoring includes using standard electrofishing techniques to identify species presence and number of individuals in each species (Ecology Lab, 2005). From March 2001 to April 2005, two native fish species (Flathead Gudgeon (Philypnodon grandiceps) and Mountain galaxias (Galaxias oildus)) and four exotic species (Goldfish (Carssius auratus), Mosquito fish (Gambusia holbrooki), Brown trout (Salmo trutta) and Rainbow trout (Oncorhynchus mykiss)) were found at eight sampling sites on the Coxs River (Figure 5.2). Exotic species of fish were recorded in greater numbers than native species in most locations over all years between 2001 and 2005, with a total of 191 native fish individuals found, and 2686 exotic fish individuals found. Mosquito fish (Gambusia holbrooki) occurred in the greatest numbers at all locations over all years (Figure 5.2).

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Figure 5.2 – Mean number of native and exotic (*) fish species recorded in the Coxs River

0

40

80

120

160

CR1 EFR2 EFR3 EFR4 RR5

Location

Mea

n N

umbe

r of I

ndiv

dual

s

Mosquito fish* Gold fish* Brown trout*

Rainbow trout* Mountain galaxias Flathead gudgeon

Source: Ecology Lab 2005

Note: See Appendix E Table 7 for location descriptions

Implication

There is inadequate data across the Catchment to assess change in fish communities during the 2005 Audit period. However, at a localised level, the number of exotic fish species in the Coxs River may indicate a moderate level of disturbance to native species, flows or riparian vegetation structure in this area.

The large proportion of exotic fish species was highlighted in the 2003 Audit Report as a priority and a number of management options discussed including managing the health of riparian areas, and direct removal of exotic species through initiatives such as the ‘daughterless carp’ program. The 2003 Audit Report also suggested that management initiatives be prioritised to infested areas, particularly in storages and inflows to storages. The 2005 auditor has inadequate new information to suggest an alternative approach. More information about fish communities across the Catchment should be obtained for the next audit.

Cold water pollution

The SCA monitors the temperature of water releases at a number of sites downstream of dams. During 2003 and 2004 the SCA monitored downstream of Woronora, Warragamba and Tallowa Dams. There was little difference between the median annual temperatures upstream and downstream of Woronora Dam. There were inconclusive results for releases from the Warragamba Dam due to confounding factors and variable results. Releases from Tallowa Dam caused a decrease in Shoalhaven River temperatures with median annual water temperatures above Tallowa Dam ranging from 15°C to 21°C and median downstream temperatures of 14.6°C. Temperatures 10 degrees below ambient have been shown to have negative effects on some fish species and other organisms (Astles et al. 2003).

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Disruption to fish passage

Instream structures such as weirs, causeways and bed-control structures can prevent fish movement and migration. The SCA confirmed the presence of 68 weirs in the Catchment. None of these weirs were found to provide effective fish passage.

The Sydney Metropolitan CMA funded a project to review fish passage in urbanised areas in 2004–05. The project, undertaken by DPI, identified in-stream structures that disrupt fish passage, prioritised them in order of importance and presented options for remediation. Woronora River and O’Hares Creek sub-catchment were included in the study. Seven structures in the Woronora River sub-catchment were identified as impeding fish passage, with two recommended for remediation. These included a causeway in Woronora River and a weir on Heathcote Creek. Two river gauging stations in the O’Hares Creek sub-catchment were recommended for removal (if the structures were no longer required).

DPI is currently undertaking several state-wide projects that relate to fish passage, including two Environmental Trust-funded projects within the Hawkesbury–Nepean and Shoalhaven River catchments. One project includes a review of waterway crossings requiring fish passage remediation. The second project aims to build on the outcomes of the NSW Initial Weir Review by undertaking detailed reviews of 80 high-priority fish passage barriers in NSW. Eight weirs were investigated in the Hawkesbury catchment and 10 weirs in the Shoalhaven catchment as part of this program. Both the waterway crossings and weirs projects are due for completion in January 2006 and will include an on-ground works component where remediation options for barriers are demonstrated.

Figure 5.3 – Berrima Weir is an example of a weir that was identified as a barrier to fish – requiring a detailed review in the Initial Weir Review project.

Future directions

A fish monitoring program in the Catchment is still needed, as recommended in the 2003 Audit Report. As indicated in the background of this Chapter, fish interact on many trophic levels, they are mobile and have a lifespan which enables fish populations to be used to assess changes in ecosystem health over time. Integrated with monitoring programs for water quality, macroinvertebrates and riparian vegetation, a fish monitoring program is likely to provide greater knowledge of Catchment health, and provide greater confidence that management responses address identified ecosystem health concerns.

Sampling of fish at designated sites should be carried out approximately every three years to determine the status of, and changes in, the composition of fish communities and to measure the success of any exotic fish control initiatives. This timeframe is consistent with that used in the Sustainable Rivers Audit of the Murray Darling Basin. Such integration may also enable more focussed management responses to identified issues. See Recommendation 3 and Recommendation 24 below.

Recommendation 24: The NSW DPI, in consultation with the SCA, develop a fish community monitoring program for the Catchment to assist the management of aquatic ecosystem health.

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Case Study – Mosquito Fish (Gambusia holbrooki)

Gambusia holbrooki, common name Mosquito fish, is native to the rivers of south-eastern America. The species was initially introduced into NSW waters sometime during the 1920s because of its reputation for mosquito control. However its ability to control mosquito larvae appears no greater than that of small native fish that feed on insects.

Mosquito fish are now widespread in fresh coastal and inland waters throughout most Australian states, spreading widely throughout NSW, especially in modified waterways. The Mosquito fish is a major pest species in the freshwaters of eastern New South Wales. Mosquito fish have been declared as a Class 1 noxious fish (outside the greater Sydney area), with no possession of individuals allowed in aquariums, garden ponds or farm dams (NSW DPI (Fisheries), 2001).

Mosquito fish prefer warm water that is still or gently flowing, feeding on a wide variety of food such as ants and flies together with aquatic beetles, bugs and other fauna. They can tolerate a wide range of temperatures and water quality, with their high reproductive rate and extended breeding season, mosquito fish can overwhelm suitable native habitats with juveniles and deplete food supplies. Mosquito fish greatly outnumber native species in many waterways.

Mosquito fish have been associated with the decline of abundance or range of 35 fish species worldwide, including Australian native species such as gudgeon, hardyheads and some rainbow fish (NSW NPWS, 2003). Mosquito fish are known to prey upon the eggs and juveniles of other fish species.

Figure 5.4 – Mosquito fish (Gambusia holbrooki) Source: NSW Fisheries

Predation by Mosquito fish is listed as a key threatening process on Schedule 3 of the NSW Threatened Species Conservation Act 1995. The NSW Scientific Committee determined that predation by Mosquito fish is a serious threat to the survival of threatened species such as the green and golden bell frog (Litoria aurea) and the New England bell frog (Litoria castanea) and could cause other native frog species to become threatened (NSW NPWS 2003).

There are presently no completely effective or specific methods to control Mosquito fish, although the National Parks and Wildlife Service (NPWS) recommends a combination of water reform, river health programs and aquatic restoration programs as part of a threat abatement plan published in 2003.

Figure 5.5 - Mosquito fish (Gambusia holbrooki) Source: NSW Fisheries

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5.4 Riparian vegetation

Background

Riparian zones typically consist of vegetated corridors adjacent to stream channels where the vegetation is influenced by the water. These areas can be effective barriers to pollution from land based activities, including agricultural 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 range of species.

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. The primary pressures on riparian vegetation are removal of riparian vegetation, introduced plant species (eg. Willows) and stock access.

This Audit focuses on the extent and condition of riparian vegetation in the Catchment. The Audit also reports on the area of vegetation cleared in the riparian zone during the audit period, and provides information on restoration and protection programs in the Actions and Response section of this chapter.

Findings

The SCA estimated there is 81,125 hectares of riparian zone in the Catchment of which native vegetation covers 54,787 hectares and 23,806 hectares is pasture (SCA, 2003a). It was estimated in SCA’s Annual Environment Report (2001) that 21,000 km (38%) of watercourse within the Catchment is presently being, or has the potential to be, accessed by stock.

The SCA developed a riparian zone index in 2002 to measure the proportion of standing vegetation (with no discrimination between native and exotics) in the riparian zones in the Catchment. The SCA applied this index across the Catchment in 2004. Based on this index, riparian zones in National Parks and Special Areas have a good proportion of standing vegetation, while the Braidwood Creek, Back and Round Mountain Creek and Jerrabattgula Creek sub-catchments have a low proportion of standing vegetation cover, and Upper Wollondilly River (priority) and Mulwaree River (priority) sub-catchments have little to no standing vegetation along riparian zones (SCA, 2004).

The CRC for Freshwater Ecology (Williams and Roberts, 2005) undertook a Synoptic Biodiversity Survey funded by the SCA in 2001. The purpose of this survey was to provide a preliminary assessment of the distribution and variability of riparian biodiversity within the Catchment. The study examined 40 riparian sites (see Map 5.3 for locations). Three (7.5%) of these sites had less than 25% cover of native species. These three sites were located in urban areas at Lithgow, Bowral and Goulburn. Fifteen of the 40 sites (37.5%) had 25–50% native species in the riparian zone, many of which were in the priority sub-catchments of Upper Coxs River, Mid Coxs River, Wingecarribee River, Wollondilly River, Upper Wollondilly River and Mulwaree River. The Reedy Creek, Braidwood Creek, Back and Round Mountain Creek and Jerrabattgula Creek sub-catchment also had sites with 25-50% native species. Seven sites (17.5%) had more than 75% of native species in the riparian zone, and these sites are located in the Nattai River, Woronora River, Nerrimunga Creek, Mongarlowe River and Upper Shoalhaven River sub-catchments.

The exotic plant species which occurred in more than 50% of sites surveyed in the CRC for Freshwater Ecology riparian study (Williams and Roberts, 2005) are listed in Table 5.1. Both Blackberry (Rubus fruticosus) and Scotch thistle (Cirsium vulgare) are classified as W2 or W3 weeds under the Noxious Weeds Act 1999. Landholders are required to fully and continuously suppress and destroy W2 species, and W3 species are to be prevented from spreading, and to have their numbers and distribution reduced.

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Table 5.1 – Exotic plant species occurring in more than 50% of riparian sites in the Catchment

Common Name Species Name % of sites Flatweed Hydrochaeris radicata 75 Plantain Plantago lanceoloata 58 Blackberry Rubus fruticosus 53 Yorkshire fog grass Holcus lanatus 53 Scotch thistle Cirsium vulgare 53 Self heal Prunella vulgaris 50

Source: Williams and Roberts, 2005

A number of clearing applications were approved during the 2005 Audit period under the Native Vegetation Conservation Act 1997 to remove a total of 240.43 hectares of exotic species in riparian zones across the Catchment. The majority of applications were to remove willow species from the riparian zone of the Wollondilly River (61.9 ha), Mulwaree Ponds (2.27 ha), Mulwaree River (1.72 ha), Wingecarribee River (21.55 ha), Shoalhaven River (19.71 ha), Tarlo River (4.89 ha), Coxs River (110.68 ha), Jinden Creek (0.43 ha) and Sooley Creek (3.07 ha). The SCA also removed 357 hectares of willows during the 2005 Audit period which was an increase from the 202 hectares removed during the 2003 Audit period.

Figure 5.6 – Poisoned willow as part of a willow removal program along the Coxs River, October 2005

Implication

There are riparian areas within the Catchment with good proportions of standing vegetation and native vegetation cover, particularly in the Special Areas. However, there are also riparian zones within the catchment that are likely to be under variable pressure, from little to no standing vegetation cover, areas of pasture, stock access, and the presence of exotic species. These conditions can threaten ecosystem health and water quality. More information is needed on the extent and condition of riparian vegetation outside the Special Areas to quantify the pressure and assist with prioritising management programs.

Map 5.3 – Percentage of native species in the riparian zone in the Sydney Drinking Water Catchment

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Healthy riparian zones assist in maintaining the health of rivers and streams in the Catchment, thereby enhancing the first of the multiple barriers in protecting drinking water quality (Section 2.2). Riparian zones are particularly important for water quality in areas where the adjacent land is subject to activities such as agricultural or urban land use.

The Braidwood Creek, Back and Round Mountain Creek and Jerrabattgula Creek sub-catchments have low standing vegetation cover in the riparian zones as shown by the SCA’s Riparian Zone Index. The Upper Wollondilly River (priority) and Mulwaree River (priority) sub-catchments have little to no vegetation in the riparian zone. Water quality and ecosystem health is potentially at risk in these sub-catchments.

Weed removal along riparian zones, such as willow elimination, can cause disturbance in the riparian zone and can lead to erosion and water quality impacts. Management of weed removal sites in the riparian zone should include follow up measures to prevent secondary impacts.

Future directions

The SCA’s Healthy Catchment Protection Riparian Strategy outlines a number of on-ground works to protect and rehabilitate riparian zones. The on-ground rehabilitation works should be targeted in the Upper Wollondilly River (priority), Mulwaree River (priority), Braidwood Creek, Back and Round Mountain Creek and Jerrabattgula Creek sub-catchments, as these sub-catchments have low to no standing vegetation in the riparian zone.

There are many programs for restoration and rehabilitation of riparian zones, which are all likely to contribute to an improvement in the health of riparian zones and provide improved protection of water quality. 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 aggregate information about the extent of riparian restoration and rehabilitation across sub-catchments or the whole Catchment, although information about individual programs is presented in the Actions and Response section of this Chapter. This information should be collected systematically across the Catchment to enable better information for both future audits and development and co-ordination of management decisions (See recommendation 2). The type of information on riparian works that may be useful includes:

• areas of weed removed from riparian zones

• length of riparian zone fenced to prevent stock access

• area of riparian zone revegetated or rehabilitated.

5.5 Native vegetation

Background

Native vegetation within the Catchment is important for maintaining the health of individual species of flora and fauna, ecosystem process and genetic diversity. The degradation or clearing of native vegetation can impact on critical ecosystem services such as water quality, nutrient recycling and resources such as food and fibre. Impacts on native vegetation can also induce soil salinity and acidity, soil erosion, loss of nutrients, changes to flow regimes and climate change. The presence of exotic weed species can affect the condition of native vegetation and the extent to which it can provide habitat. The rate of biodiversity loss accelerates dramatically when a vegetation community declines below approximately 30% of its original area.

Native vegetation mapping in the outer Catchment was undertaken during the 2005 Audit period by the former DIPNR (Map 5.4). This mapping is more descriptive than what was presented in the 2003 Audit report. There are however, small areas in the Upper Coxs River (priority), Kowmung River and Upper Wollondilly River (priority) sub-catchments, which are currently being mapped as part of a project funded by the Hawkesbury–Nepean CMA.

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This audit examines the extent and condition of native vegetation in the Catchment, as well as the area of:

• native vegetation cleared

• weeds removed

• revegetated and rehabilitated parts

• vegetation protected in National Parks and Reserves.

Findings

Native vegetation covers approximately 50% of the Catchment (Map 4.1) based on new land-use mapping completed during the 2005 Audit period by the DNR. It should be noted that the 2003 Audit report estimated that 63% of the Catchment is covered by native vegetation based on data from the Eastern Bushland Database.

The Kowmung River, Lower Coxs River (priority), Lake Burragorang, Little River, Nattai River, Woronora River, O’Hares Creek, Upper Nepean River and Upper Shoalhaven River sub-catchments have a large percentage of native vegetation cover (>80%). The sub-catchments with the lowest percentage of native vegetation cover (<20%) are the Upper Wollondilly River (priority) and Mulwaree River (priority) (see Map 5.4).

The SCA has recently undertaken an analysis of the change in the extent of native vegetation between March 1988 and October 2002, and the levels of clearing within each sub-catchment. While outside the 2005 Audit period, this analysis provides useful information about the rate of change in extent of native vegetation in key sub-catchments. The extent of native vegetation decreased by 0.76% in the Catchment during the study period (1988–2002). The highest increase in cleared land between 1988 and 2002 was in Back and Round Mountain Creek and Werriberri Creek (priority) sub-catchments. Wollondilly River (priority), Lake Burragorang and Reedy Creek had 0.5% of the total native vegetation cleared during the study period, and there was a decrease of 0.65% of land cleared at Upper Wollondilly (priority) during the study period.

Approvals under the Native Vegetation Conservation Act 1997 were granted for the removal of 30.96 hectares of native vegetation in the Catchment during the 2005 Audit period. This is far less than the 728.76 hectares of native vegetation removed from the Braidwood district alone during the 2003 Audit period. The extent of clearing in the Braidwood Creek sub-catchment during the 2005 Audit period was limited to 4.56 hectares of Eucalyptus seeberi for the construction of a high voltage electricity line to supply Rose Meadow customers, and 22.1 hectares of native Poa tussock grass (Poa labillardieri) removed by aerial spraying and re-seeded with improved pasture.

Track construction in protected land resulted in 0.18 hectares of clearing of Eucalyptus macrohyncha in the Wollondilly River (priority) sub-catchment and the clearing of 0.18 hectares of Eucalyptus eugenoides in the Upper Coxs River (priority) sub-catchment.

During the 2005 Audit period, DEC acquired a total of 3,665 hectares in the Catchment, including land in the Bees Nest Nature Reserve, Blue Mountains National Park, Deua National Park, Hartley Historical Site, Illawarra Escarpment State Conservation Area, Marangaroo (Mt Walker) and Morton National Park. A number of Wilderness Areas in the Catchment were also declared in 2003–04, including Budawang, Kanangra-Boyd, Nattai and Woila Deua (DEC, 2004).

Restoration and protection programs are detailed in the Actions and Response section of this Chapter.

The majority of the native vegetation in the Warragamba and Metropolitan Special Areas have low disturbance (Map 5.5 and Figure 5.7). There are however, large areas in the Special Areas where native vegetation has been cleared or impacted.

Map 5.4 – Native vegetation in the Sydney Drinking Water Catchment

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Figure 5.7 – Nepean River in the Metropolitan Special Area, October 2005

Implication

There was a significant reduction in the area of native vegetation cleared with approval under the Native Vegetation Conservation Act 1997 compared to during the 2003 Audit period, which is a positive outcome for ecosystem health and protection of water quality in the Catchment.

The lowest percentage of native vegetation cover is in the Upper Wollondilly River (priority) and Mulwaree River (priority) sub-catchments. The low percentage cover of native vegetation in these sub-catchments may put water quality and ecosystem health at risk.

Some areas of the Catchment play a particularly important role in preventing pollutants entering the water supply and proper management and ongoing monitoring of vegetation within these areas is clearly important in maintaining water quality and quantity. These areas include those in immediate proximity to the water storages, riverine corridors (over 18°) and flood prone lands. Detailed studies of the extent and condition of native vegetation can indicate the general state of ecosystem diversity and promote greater understanding of a catchments capacity to yield high water quality.

Future directions

Vegetation mapping for the entire Catchment should be completed by December 2005. Additional information and mapping is needed on the condition of native vegetation in the outer Catchment to provide greater capacity and support to decisions about where management responses are required, particularly for areas outside the Special Areas where there is less direct and formal management arrangements for vegetative communities. The condition and relative significance of the native vegetation that is not in protected or managed areas should be determined using similar methodology used in DEC Special Areas condition assessment (Map 5.5).

All on-ground works being undertaken or funded by Government to revegetate and rehabilitate native vegetation should be integrated and a spatial database of location, type and area of works created and maintained. See Recommendation 2.

Recommendation 25: The DNR, DEC and the SCA jointly undertake vegetation condition mapping of areas outside the Special Areas.

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Actions and Response

Response to Issue

There are many responses to the degradation of ecosystem health including programs to reduce the impacts of pollution (Chapter 2), new water management rules under statutory water sharing plans (Chapter 3) and programs to improve land management (Chapter 4). In addition there are specific responses to the degradation of ecosystem health, including:

• programs to monitor ecosystem water quality

• programs to monitor macroinvertebrates

• programs to maintain and enhance native fish communities

• programs to maintain and enhance riparian zones

• programs to maintain and enhance native vegetation.

Programs to monitor ecosystem water quality and macroinvertebrates

In addition to SCA’s water quality monitoring program, there are several more localised long-term water quality monitoring programs in the Catchment including:

• Streamwatch Program – community/school-based assessment of water quality and macroinvertebrates in local streams. There are 112 Streamwatch locations across the Catchment

• Wingecarribee Shire Council – water quality assessment survey to examine the performance of STP upgrades and assess the impacts on local receiving waters

• Goulburn City Council – Wollondilly and Mulwarree Ponds Water Quality Survey – assessment of water quality in Wollondilly and Mulwaree ponds for managing ecosystems health

• Lithgow City Council – recreational water quality assessment of Lake Lyall

• Blue Mountains City Council – Blue Mountains Water Monitoring Program to measure physical parameters for recreational and aquatic values.

The draft Regional Environmental Plan (REP) includes a Catchment Management Strategy which states that a water quality monitoring program will be undertaken at a sub-catchment level to inform rectification action planning and enable assessment of achievement against water quality objectives.

Programs to maintain and enhance native fish communities

CSIRO is researching Daughterless carp gene technology. This technology involves manipulating the genes of carp to produce an inheritable ‘daughterless carp’ gene which prevents fish from developing as females. This would result in fewer and fewer females being produced each generation until the carp population was mostly male. However, the technology needs to be further developed and thoroughly tested before it can be released.

The NSW DPI has initiated the following relevant programs for fish management:

• Fisheries have been undertaking surveys of carp populations within the Catchment for the Australian Invasive Animals CRC. This has included sampling for both larval and adult fish in order to determine ‘hot-spots’ of carp breeding. It is also undertaking a comparative analysis of age, sex, genetic, spatial and temporal dynamics of carp populations. This project continues to provide insights into the ecology of invasive carp and will help to create a very sound basis for the design of integrated pest management approaches.

Map 5.5 – Vegetation disturbance in the Special Areas in the Sydney Drinking Water Catchment

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• National Plan for Macquarie Perch, including a Macquarie perch survey to be undertaken in the Woronora River.

• Bass Habitat Restoration at Broughton Creek and Kangaroo River, funded by the Recreational Fishing Freshwater Trust Habitat Grant. The project was undertaken during 2003, and involved the removal of privet and replanting endemic riparian species to improve the habitat for Macquarie Perch and Australian Bass.

• Reducing the impact of road crossings on environmental flows, water quality and fish passage funded by the Environmental Trust – 75% of road crossings in the Hawkesbury–Nepean catchment have been assessed and the priority road crossing for remediation identified.

• Weir Review Program, as discussed in Section 5.3.

The SCA commenced design for a $7 million fishway and multi-level offtake point at Tallowa Dam in 2003. The fishway would enable migratory fish species to access the Shoalhaven and Kangaroo Rivers, upstream of the 42 metre high dam wall at Tallowa.

The Sydney Metropolitan CMA undertook a project between May 2004 and May 2005 to review fish passage in urbanised areas. The project identified in-stream structures that disrupt fish passage, prioritised them in order of importance and presented options for remediation. The Woronora River and O’Hares sub-catchment were included in this project.

Programs to maintain and enhance riparian zones

The SCA’s Healthy Catchment Program includes a Riparian Strategy to improve the condition of riparian zones in the Catchment. The Strategy requires the identification of the condition of the riparian zone within the Catchment and provides for grants and assistance schemes, education programs and regulatory processes in consultation with appropriate authorities. As discussed in Section 5.4, the SCA has completed a riparian zone index in 2003–04 to assist implementation of this strategy.

The SCA has provided financial assistance to various organisation and landholders for on-ground work to improve riparian vegetation, including:

• Almost $100,000 of funding to landholders during 2003–04 in the Coxs River sub-catchment for on-ground works including the removal of Salix cinerea willows and other weeds, revegetating with native trees and removing rubbish. 13 km of works have been completed to date.

• Willow control above and within Cecil Hoskins Nature Reserve and along other sections of the Wingecarribee River. The work above the Reserve was part of a three year Salix cinerea program undertaken by SCA in partnership with the then DIPNR and Wingecarribee Shire Council.

• Riparian revegetation and weed control along Werriberri Creek in conjunction with the Hawkesbury Nepean CMA and Wollondilly Shire Council. The work was undertaken in May and June 2005 and involved the removal of about one hectare of privet, Blackberry and Japanese Honeysuckle.

• Various riparian restoration projects in the Kangaroo River sub-catchment to eradicate privet and madeira vine infestations.

The Hawkesbury–Nepean CMA is also preparing a River Health Strategy at the request of the Minister for Natural Resources. The Strategy has been developed by assessing 150 river reaches to understand values ad pressures on each reach. The Strategy aims to maintain the condition of natural or near natural reaches, maintain and improve good condition reaches and improve environmental condition in the remaining reaches. While broader than riparian vegetation, the Strategy will assist the CMA to invest in programs such as riverbank management in a prioritised manner. The Strategy is expected to be submitted to the Minister for Natural Resources in December 2005.

The Hawkesbury–Nepean CMA removed Willows from a 750 m length of the Wollondilly River under the Catchment Protection Scheme in 2004–05. In addition, the Hawkesbury–Nepean CMA has developed a number of riparian zone management projects which help to protect riparian vegetation. These include:

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• Warragamba Riparian Biodiversity Project, which provides technical advice and funds to landholders to carry out on-ground works including revegetation, weed and erosion control, fencing and providing stock with alternate watering sources. The following works were completed during 2004–05:

o 585 ha of riparian landscape rehabilitated or protected

o 39 km of riparian zone fenced and protected from stock

o 80,367 native tubestock planted to enhance riparian zones

o 85 km of riparian zone treated for weeds

o 11 off-river stock watering systems installed.

• Targeted Pussy Willow Control Program, which aims to control and where possible stop the spread of Pussy Willow (Salix cinerea) across the Wingecarribee Shire. The following works were undertaken during 2003–04:

o 14 properties were treated for pussy willow

o 75% of a large infestation at Cecil Hoskens Nature Reserve in Moss Vale was controlled.

The Southern Rivers CMA is also administering a South-east integrated river and wetland protection and rehabilitation program, a Riparian partnership project and the Kangaroo River and Broughton Creek Privet Reduction Program in the Kangaroo River (priority) sub-catchment.

The degradation of native riparian vegetation along NSW water courses was also listed in November 2001 as a key threatening process under the Fisheries Management Act 1994. Once listed, the NSW DPI may prepare a threat abatement plan to identify actions required to manage the key threatened process so as to abate, ameliorate or eliminate its adverse effects on threatened biodiversity.

Programs to maintain and enhance native vegetation

Actions to maintain and enhance native vegetation include formally protecting high conservation areas, minimising clearing, removing weed infestation and revegetating cleared areas to restore biodiversity values.

Programs to protect high conservation areas

As discussed in Section 5.5, the areas of land protected in National Parks and reserves has increased during the 2005 Audit period. In addition, DEC also administers three mechanisms that enable landholders to formally protect conservation value, including native vegetation. These mechanisms are:

• Voluntary conservation agreements (VCAs) which are a permanent legal protection for the property’s special features, through an agreement between the landholder and the Minister for the Environment

• Wildlife refuges, where specified land is legally declared a wildlife refuge, and the terms of the agreement can be changed over time

• Land for Wildlife, where information is provided to landholders to help conserve the bushland.

Other initiatives such as the Southern Rivers CMA’s Southern Rivers Bush Incentives program funds the management of selected sites on private land that have high conservation native vegetation. The Southern Rivers CMA has also implemented a comprehensive voluntary biodiversity conservation scheme for south-east NSW, as well as projects to protect biodiversity in the Southern Catchment and revegetation of the Braidwood Granites.

Programs to manage vegetation clearing

The Native Vegetation Act 2003 sets a legal framework for ending broadscale clearing unless it improves or maintains environmental outcomes, encouraging revegetation and rehabilitation of land with native vegetation, and rewarding farmers for good land management. Landholders seeking to clear native

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vegetation are now required to either submit a development application, or enter into a legally binding agreement with the local CMA called a Property Vegetation Plan.

The NSW Government has recently amended the Threatened Species Conservation Act 1995. The key amendments included:

• the integration of biodiversity into strategic land use planning under the EP&A Act

• the accreditation of flora and fauna consultants

• embedding threatened species conservation in native vegetation protection and incentives schemes

• transparent prioritisation of recovery and threat abatement actions

• upgraded enforcement and compliance provisions.

Weed control and native vegetation management programs

• The SCA’s Pest and Weed Control Program for Special Areas focuses on the control of blackberry, serrated tussock, pampas, willows and privet, and on feral goats, deer and pigs.

o The control of serrated tussock included the SCA treating 264 hectares in Braidwood, Upper Nepean, Shoalhaven and Warragamba catchments, with DEC treating 1,210 hectares in the Joorilands area.

o Control of willows included the SCA treating 128 hectares in the Shoalhaven Catchment.

o SCA also funded a $5 million weed control program on the Wingecarribee Swamp. The program aims to eradicate or reduce infestations of pussy willows to a manageable level.

• The Hawkesbury–Nepean CMA has implemented a Warragamba Terrestrial Biodiversity Program which aims to protect and improve good quality remnant vegetation including native grasslands, woodlands and forests to increase the biological diversity of these remnants and to protect them from future degradation. As part of this program the following works were undertaken during 2004–05:

o 588 hectares of remnant vegetation was protected by 42 kilometres of fencing

o 27 kilometres of direct seeding

o 15,600 tubestocks were planted

o 230 hectares of direct weed control.

• Various other restoration projects in the Catchment during the 2005 Audit period were funded through the National Heritage Trust, including:

o Glowworm Glen Wetland Study undertaken by the Glowworm Glen Bushcare Group and Wingecarribee Shire Council

o Mount Gibraltar Forest Regeneration and Protection Project undertaken by the Mount Gibraltar Landcare and Bushcare and Wingecarribee Shire Council

o Linking a Bushland Remnant to a Riparian Zone on the Wollondilly River undertaken by F Downes and C Pryma at Canyonleigh

o Protecting High Conservation Value Riparian Vegetation Along Trimble Creek at Kangaroo Valley in the Kangaroo River (priority) sub-catchment, undertaken by Centre For Leadership Pty Ltd

o Berkeley Brush Dry Rainforest Restoration Project in the Nerrimunga Creek sub-catchment, by the Budjong Creek Land Care group

o Protection and Restoration of a Mulloon Creek Drained Wetland for Biodiversity and Sustainable Land Use in the Reedy Creek sub-catchment, by Coote, Anthony Edmund Rundle.

• Landcare and Bushcare groups operate in the Catchment, undertaking work to protect and restore native vegetation.

Audit of the Sydney Drinking Water Catchment 2005 108

• Local Councils undertake or facilitate many on-ground works for restoring and maintaining native vegetation in the Catchment. A few examples include:

o Wollondilly Council restoration of Werriberri Creek in the Werriberri Creek (priority) sub-catchment

o Wollongong City Council carried out riparian zone restoration in the Mid Shoalhaven River sub-catchment with Gallaghers Creek Bushcare group

o Wingecarribee Shire Council programs included:

o blackberry control on Wingecarribee River at Berrima, in collaboration with the Hawkesbury–Nepean CMA, local landholders and Berrima Bushcare

o creek bank restoration at Gibbergunyah Creek, Mittagong Creek, Whites Creek at Moss Vale, Iron Mines Creek, Medway Rivulet at Sutton Forest, Caalang Creek at Robertson, Wingecarribee River and the creekline below Lake Alexandra

o Bushland rehabilitation at Penrose, Mt Gibraltar, Robertson, Mt Alexandra Reserve, Berrima Common, Bong Bong Common, Hammock Hill, Mansfield Park, Wingello Forest, Cunningham Park, Yerrinbool and Welby

o Bush regeneration work in 15 bushland reserves by council’s bush regeneration team.

o Blue Mountains City Council has a number of programs including:

o support of 50 local Bushcare and Landcare groups

o a noxious weeds program is focused on treating weeds in our urban areas

o Weedpoint – a system that allows officers to use portable computers to map the location of noxious weeds on private land on-site

o BlueSpace weed mapping database – the weed mapping system was redesigned to accommodate new weed mapping information in conjunction with the CRC for Australian Weed Management

o Bush Backyards Scheme to set up a network of landowners who have a commitment to native plant and animal conservation on their property to provide significant habitat

o assistance to rural landowners to develop weed management plans, subsidised participation in land management workshops and courses, and facilitation of grant applications for sustainable pasture management, fencing, weed control and revegetation

o Goulburn-Mulwaree Council completed a South Goulburn Vegetation Management Plan.

Other programs

The Local Government Association has developed the Urban Forest Policy which aims to improve urban forest planning, management and practices throughout NSW Local Government areas.

The Lithgow and District Community Nursery is providing between 30,000 and 40,000 local trees and shrubs to the community and rehabilitation of Paralucia spinifera (copper winged butterfly) habitat adjacent to the nursery property (see case study).

Gaps in the response

The monitoring of ecosystem water quality and macroinvertebrate communities provides useful information about the state of the Catchment. Actions that respond to and investigate reduced water quality and impaired macroinvertebrate communities now need to be developed and implemented based on this monitoring information.

Ecosystem Health 109

Programs to improve fish passage now need to be implemented. Partnerships between a number of stakeholders will be needed to ensure major projects such as the removal or modification of barriers to fish passage are achieved.

There are many programs for the restoration of riparian and native vegetation which will contribute to improved ecosystem health. These programs need to be coordinated across the Catchment to ensure priority areas are targeted for funding and on-ground works.

Case Study – Lithgow and District Community Nursery Lithgow and District Community Nursery has been established on the old Hermitage Colliery site for the past 4 years. Rehabilitation of the former washery site included removal of coal piles, levelling and application of pebbles over the entire surface.

The nursery grows only local native plants from seed (Figure 5.8). For the past 14 years the nursery has been working to protect threatened plant and animal species, re-green Lithgow valley and educate the local community. It provides between 30, 000 and 40,000 local trees and shrubs per annum to groups such as Landcare, Delta Electricity, RTA and schools.

Figure 5.8 – Lithgow and district community nursery native plants

Along with the rehabilitation of the degraded mine site a large section of Paralucia spinifera (Copper winged butterfly) habitat is being rehabilitated beyond the fence of the nursery grounds (Figure 5.9). The butterfly (Figure 5.10) is an endangered species that is only found in 15 locations within this immediate area. The rehabilitation involves clearing pest and weed species and revegetating with Bursaria spinosa the native blackthorn shrub.

Figure 5.10 – Copper winged butterfly

Figure 5.9 – Rehabilitation of Copper winged butterfly habitat beyond the fence of the Lithgow and district community nursery

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Acronyms 119

Acronyms

ANSTO – Australian Nuclear Science and Technology Organisation

ANZECC – Australian and New Zealand Environment and Conservation Council

ARMCANZ – Agriculture and Resource Management Council of Australia and New Zealand

ASU – Area Standard Unit

AusRivAS – Australian River Assessment System

BOD – Biological Oxygen Demand

BWSA – Bulk Water Supply Agreement

CAP – Compliance Activity Plan

CMA – Catchment Management Authority

CRC – Cooperative Research Centre

CSIRO – Commonwealth Scientific and Industrial Research Organisation

DEC – Department of Environment and Conservation

DIPNR – Department of Infrastructure, Planning and Natural Resources

DLWC – Department of Land and Water Conservation

DMR – Department of Mineral Resources

DNR – Department of Natural Resources

DoP – Department of Planning

EASI – Environmental Assessment of Sites and Infrastructure

EBD – Eastern Bushlands Database

EP – Equivalent Population

EPA – Environment Protection Authority

ESD – Ecological Sustainable Development

HCP – Healthy Catchments Program

H-N CMA – Hawkesbury-Nepean Catchment Management Authority

HNRMF – Hawkesbury Nepean River Management Forum

HRC – Healthy Rivers Commission

IPART – Independent Pricing and Regulatory Tribunal of NSW

LEP – Local Environmental Plan

NDVI – Normalised Difference Vegetation Index

NHMRC – National Health and Medical Research Council

NHT – National Heritage Trust

NLWRA – National Land and Water Resources Audit

NPWS – National Parks and Wildlife Service

NSW DPI – New South Wales Department of Primary Industries

Audit of the Sydney Drinking Water Catchment 2005 120

PRP – Pollution Reduction Program

PSR – pressure-state-response

RACC – Regional Algal Coordinating Committee

RAP – Rectification Action Plan

REP – Regional Environmental Plan

RUSLE – Revised Universal Soil Loss Equation

SCA – Sydney Catchment Authority

SEPP 58 – State Environmental Planning Policy 58

SIRIS – Sustainable Investment Research Institute

SLWCA – Strategic Land and Water Capability Assessment

SMP – Subsidence Management Plan

SoE – State of the Environment

SOI – Statement of Intent

STP – Sewage Treatment Plant

WFP – Water Filtration Plant

Appendix A 121

Appendix A

Table 1 – Criteria for identifying a sub-catchment as being under pressure in Table ES1 Executive Summary

Indicator number Indicator or issue Criteria

Phosphorus Top 5 sub-catchments with estimated annual load of phosphorus Figure 2.1 Nitrogen Top 5 sub-catchments with estimated annual load of nitrogen Figure 2.2 STP Bowral – the greatest number of bypasses, Goulburn – the greatest number of overflows Table 2.2

2.1

Unsewered Sub-catchments with an unsewered village population of > 1000 Table 2.3

2.2 Water quality at WFPs Exceedence of the BWSA in > 50% of samples at Cascade, Greaves Ck, Kangaroo Valley, Macarthur, Nepean and Wingecarribee WFPs Table 2.5

2.3 Algae blooms Sub-catchments with an incidence of >2 000 cells/ml of toxic cyanobacteria Map 2.4 2.4 Pathogens Sub-catchments with > 5% of samples with incidences of Cryptosporidum or Giardia Map 2.5

Extraction licences Sub-catchments with > 2000 megalitres licence for extraction per annum Figure 3.1 3.1

Farm dams Sub-catchments with density > 1 farm dam / 1km2 Map 3.1 3.2 Groundwater bores Sub-catchments with density > 3 groundwater bores / 10km2 Map 3.2

Weirs Sub-catchments with > 10 weirs or barriers Map 3.3 3.3

Transfers Increase in volume of water transferred by 50% Table 3.1

Increasing urbanisation Sub-catchments with > 100 SEPP 58 dwelling applications Figure 4.1 4.1

Other developments Sub-catchments with > 25 SEPP 58 other development applications Figure 4.2

4.2 Sites of pollution or potential contamination

Sub-catchments with density > 1 site of pollution or potential contamination with medium, high or very high risk / 10km2 Map 4.2 and 4.3

4.3 Soil erosion Sub-catchments with very high or high estimated erosion Map 4.4 4.4 Dryland Salinity Sub-catchments with widespread risk of salinity Map 4.5

5.1 Ecosystem water quality A location in a sub-catchment with 3 or 4 parameter groups with a very poor WQ rating Map 5.1

5.2 Macroinvertebrates A location in a sub-catchment with an AusRivAS health rating of severely or significantly impaired Map 5.2

5.3 Fish Sub-catchments which have observed exotic species Pages 95 and 96 5.4 Riparian vegetation A location in a sub-catchments with < 50% native vegetation cover in the riparian zone Map 5.3 5.5 Native vegetation Sub-catchments with < 20% native vegetation cover Map 5.4

Appendix B 123

Appendix B

Individuals and organisations who provided a submission or response to the Sydney Drinking Water Catchment Audit

Individuals

AW Bathgate

Chris Jonkers, Julie Favell and Connor Favell

Leon Francis

Ninian F Struthers

Ted Westwood

Organisations

Department of Commerce

Department of Energy, Utilities and Sustainability

Department of Environment and Conservation (DEC)

Department of Infrastructure, Planning and Natural Resources (DIPNR)

Department of Local Government

Hawkesbury–Nepean Catchment Management Authority

Hunter Water Corporation

IPART

NSW Aboriginal Land Council

NSW Department of Health

NSW Department of Primary Industries

Rural Fire Service

Sydney Catchment Authority (SCA)

Sydney Metropolitan Catchment Management Authority

Transgrid

Wollondilly Shire Council

Appendix C 125

Appendix C

List of stakeholders provided with a draft of the report to comment on the accuracy of information and data provided to the audit:

• Sydney Catchment Authority

• Hawkesbury–Nepean Catchment Management Authority

• Department of Natural Resources

• New South Wales Department of Primary Industries

Appendix D 127

Appendix D

Roles and Responsibilities of Stakeholders

Sydney Catchment Authority (SCA)

The SCA’s role and responsibilities are specified by the Sydney Water Catchment Management Act 1998. Section 13 of this Act identifies the SCA’s role to manage and protect the catchment areas and catchment infrastructure works, be a supplier of bulk water, and to regulate certain activities within or affecting the outer catchment and inner catchment areas. The principal objectives of the SCA defined in the Act are to ensure the catchment areas and infrastructure are managed and protected to promote water quality, the protection of public health and safety and the protection of the environment. The Act also enables an Operating Licence to be issued to authorise the SCA to provide, construct, operate, manage and maintain systems and services, in order to achieve its objectives.

The Act also requires the SCA to make arrangements with Sydney Water Corporation in relation to the standard of the quality of the water supplied to Sydney Water. The Bulk Water Supply Agreement addresses the supply of raw water to customers (primarily Sydney Water). This agreement specifies what the raw water quality to be supplied to the water filtration plants.

The SCA has a Water Management Licence, administered by DNR, for its activities in relation to the abstraction and use of water from identified water sources and water management works. The licence also specifies the quantity of water that must be made available for environmental purposes.

The SCA regulates activities in the special and controlled areas likely to impact on its ability to supply high quality raw water to its customers through the Sydney Catchment Management (General) Regulation. The SCA jointly manages the Special Areas with the Department of Environment and Conservation (NSW) under the Special Areas Strategic Plans of Management. The Plan sets the framework for a high level of protection of the natural and cultural heritage in these areas, and maintain the areas as intact buffers for the storages.

The Sydney Catchment Management (Environmental Protection) Regulation allows SCA to exercise power under the Protection of the Environment Operations Act 1997, in relation to non-scheduled activities. These powers may be exercised for the purposes of protecting catchment areas or protecting and enhancing the quality of water in catchment areas.

The SCA is also involved in the development assessment process in the Catchment under the Environmental Planning Act through a concurrence role under SEPP 58, which assists in protecting Sydney’s drinking water supply.

Department of Natural Resources (DNR) formerly DIPNR

The DNR aims to achieve coordinated and sustainable management of the State’s natural resources through an integrated catchment management framework. The DNR develops policies for natural resource management and maintains databases on the condition of the State’s land, soil, water and vegetation. The DNR is leading the development of a Water Sharing Plan for the Sydney Region, including the Catchment area. The DNR also administers water management licences issued under the Water Act 1912, such as for surface water or groundwater extractions.

128 Audit of the Sydney Drinking Water Catchment 2005

Department of Environment and Conservation (DEC)

The Department of Environment and Conservation (NSW) was established in September 2003, and joins together the Environment Protection Authority (EPA), the National Parks and Wildlife Service (NPWS), the Botanic Gardens Trust and Resource NSW. The Department of Environment and Conservation (NSW) does not encompass, but shares links with, the SCA.

DEC manages natural and cultural heritage across NSW, promotes sustainable consumption, resource use and waste management, regulates activities to protect the environment and conducts biodiversity, plant, environmental and cultural heritage research to improve decision making.

The EPA regulates potentially polluting activities under the environment protection legislation and the NPWS is responsible for maintaining the parks and reserves in NSW. The NPWS also jointly manages the catchment’s Special Areas with the SCA under the Special Areas Strategic Plans of Management.

Natural Resources Commission of New South Wales (NRC)

The Natural Resources Commission (NRC) was established by the Natural Resources Commission Act 2003 with a broad function of providing the Government with independent advice on a range of natural resource management issues. The NRC reports jointly to the Premier and the Minister for Natural Resources. The NRC's core functions are to:

• recommend state-wide standards and targets for natural resource management

• review and recommend the approval of Catchment Action Plans prepared by 13 Catchment Management Authorities across NSW

• audit Catchment Management Authorities' implementation of these plans and their effectiveness in achieving state-wide standards and targets.

Other roles on the NRC include:

• preparing to audit Water Sharing Plans under the Water Management Act 2000

• preparing to advise the Department of Environment and Conservation and some specialist committees on threatened species under the Threatened Species Legislation Amendment Act 2004 when it commences.

NSW Department of Health (DOH)

The primary aim of NSW Health is to ensure the public is provided with the best possible health care, and thus has a role in ensuring safe drinking water. The DOH monitors the quality of drinking water via information provided by the agencies it regulates, and develops standards and guidelines for the treatment of waste water.

It manages the testing program established to verify Cryptosporidium and Giardia testing results supplied by Sydney Water, the SCA and independent laboratories.

The Chief Health Officer of the DOH has the power to restrict or prevent the use of water considered unfit for human consumption.

Department of Planning (DoP) formerly DIPNR

The DoP is involved in the planning, policy and regulation in relation to the natural and built environment, rural and urban management (including urban growth, renewal and consolidation) and the development of housing policies.

Appendix D 129

The DoP is preparing the Drinking Water Catchments Regional Environmental Plan No. 1 (the REP) in conjunction with the SCA. This REP will provide catchment management strategies to improve the planning, management and knowledge base for water quality protection in the catchments. State Environmental Protection Policy 58 (SEPP 58) ‘Protecting Sydney’s Water Supply’ is currently in place to perform this function until the REP is finalised.

New South Wales Department of Primary Industries (NSW DPI)

The NSW Department of Primary Industries was formed in July 2004 with the amalgamation of Mineral Resources NSW, NSW Agriculture, NSW Fisheries and State Forests NSW. The Department partners with industry and other public sector organisations to foster profitable and sustainable development of primary industries in NSW.

The Mineral Resources Division is responsible for approving, regulating and monitoring mining and associated activities in NSW. It has a role in the rehabilitation of abandoned and derelict mine sites, and is currently rehabilitating some priority derelict mine sites in the Catchment with the SCA.

The Agriculture Division conducts agricultural research and provides practical and sustainable farm production and environmental advice to commercial farmers, graziers, horticulturists, agribusiness and other groups. This collaborative effort draws together a comprehensive range of information and knowledge which can also be disseminated through best management practices guidelines. There are extensive areas of agriculture in the Catchment.

The Fisheries Division is responsible for the sustainable management of commercial and recreational fishing, the protection of aquatic threatened species, populations and ecological communities, the protection of key aquatic habitats and the conservation of aquatic biodiversity. It carries out scientific research and resource management compliance and also provides management and advisory services. In consultation with industry and the community, Fisheries develops policies and regulations on the sustainable use of the states aquatic resources. Fisheries has undertaken substantial fish sampling in the Catchment and are currently investigating the distribution of both threatened and pest aquatic specie as well as working to ameliorate the effects of instream barriers to fish passage within the Catchment.

The State Forests Division is responsible for sustainably managing more than 2 million hectares of public native forests and a large area of planted forests in NSW. There are some areas of State Forest in the Catchment.

Local Councils

Local councils have many roles and responsibilities in the Catchment, including as:

• a regulator under the Protection of the Environment Operations Act 1997

• a land use planner using the Environmental Planning and Assessment Act 1979

• as an operator responsible for the management of infrastructure such as urban stormwater systems and sewerage services.

Catchment Management Authorities (CMAs)

Thirteen Catchment Management Authorities (CMAs) have been established across the State by the New South Wales Government to ensure that regional communities have a significant say in how natural resources are managed in their catchments. There are 3 CMAs within the Catchment, namely the Sydney Metro, Hawkesbury–Nepean and Southern Rivers.

The CMAs are locally driven organisations with a board that reports directly to the NSW Minister for Natural Resources. The CMAs are established under the Catchment Management Authorities Act 2003 (CMA Act) to coordinate natural resource management (NRM) in each catchment. The CMAs are

130 Audit of the Sydney Drinking Water Catchment 2005

responsible for involving regional communities in management of the NRM issues facing their region, and are the primary means for the delivery of funding from the NSW and Commonwealth governments to help land managers improve and restore the natural resources of the State.

The CMAs are responsible for the Catchment Blueprints which are aimed at natural resource management at a sub-catchment level. These Catchment Blueprints form the basis of the Catchment Action Plans being prepared by CMAs.

The CMAs work in partnership with the community, local government, State Government agencies, industry and individuals.

Department of Energy, Utilities and Sustainability (DEUS)

The DEUS promotes the sustainable supply and use of energy and urban water in NSW. The DEUS provides an oversight of the local water utilities in rural and regional areas. The DEUS collaborate with other government agencies, energy industry and the water utilities, consumer interest groups and other stakeholders.

Independent Pricing and Regulatory Tribunal of NSW (IPART)

IPART has a range of roles, including setting maximum water prices and administering licences that authorise water utilities, including the Operating Licences issued to Sydney Water Corporation and the SCA. IPART completed the end of term review of SCA’s Operating Licence in 2005 and a new Operating Licence will be issued to SCA on 1 January 2006.

NSW Rural Fire Service (RFS)

The RFS is responsible for the coordination and planning of bushfire fighting and hazard reduction operations throughout NSW. At the local government scale, there are Bushfire Management Committees included in the above role, including representatives from NPWS and the SCA. The SCA has worked with the RFS on improving fire management practices.

NSW Rural Lands Protection Boards (RLPB)

The RLPB is involved in the control of pest animal species and livestock diseases. It also has an advisory role to landholders. The SCA and the NPWS have worked with the RLPB to ensure the coordination of pest control strategies in the Catchment.

NSW Rural Assistance Authority

This authority administers assistance measures to rural producers and small businesses. Conservation funding exists, for example, to encourage improved and sustainable land management. Projects include woody weed control and livestock effluent control. The authority also manages the Water Reform Structural Adjustment Program which aims to improve irrigation practices, increase water use efficiency on farms, and minimise negative impacts from irrigation upon the NSW environment.

Dams Safety Committee

The statutory function of the Dams Safety Committee is to ensure all prescribed dams in NSW are safe and maintained. The Committee must also ensure that mining operations near dams do not affect the integrity of the dam or create significant water loss from a storage.

Appendix D 131

NSW Heritage Council

The main role of the NSW Heritage Council is to implement the Heritage Act 1977. This includes management design and implementation for heritage listings and an advisory role on matters affecting heritage sites. Heritage Council listings include both built and key natural environments. The Wingecarribee Swamp in the Catchment is a state listed natural site. There are many built sites of state and local heritage significance in the Catchment, including Avon, Cataract and Cordeaux Dams.

Universities

Universities are often involved in providing expertise and research support for the SCA. For example, the University of NSW and the Macquarie and Sydney Universities have been involved in research on pathogens. The University of Western Sydney has assisted in creating carbon and nutrient budgets, and Wollongong University has assisted with sediment budgets.

Industry

Industry in the Catchment is diverse and includes: mining and extractive industry, forestry and horticulture, livestock and commercial industries, and telecommunication and energy-based industry. The environmental performance of all industry is regulated by either Council, the SCA or the EPA under the Protection of the Environment Operations Act 1997. New industry is subject to development assessment processes under the EP&A Act, including SEPP 58 for developments with a high potential threat to water quality.

Residents

Individuals must seek council approval to conduct water supply work, draw water from a council water supply, conduct sewerage or stormwater works, or connect a private drain or sewer to a public drain or sewer. Residents can have a role in community groups which are active in decision making. All residents have a basic responsibility to prevent pollution.

Appendix E 133

Appendix E

Figure 1 – The percentage of samples with > 2000 cells/mL of toxic cyanobacteria for the 2001, 2003 and 2005 Audit periods

0

20

40

60

80

100

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AK AL Total

Sample sites

% o

f sam

ples

with

> 2

000

cells

/mL

1999-2001 2001-2003 2003-2005

Source: SCA 2005

Figure 2 – The percentage of samples with > 2000 cells/mL of total cyanobacteria for the 2001, 2003 and 2005 Audit periods

0

20

40

60

80

100

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AK ALTotal

Sampled sites

% o

f sam

ples

with

> 2

000

cells

/mL

1999-2001 2001-2003 2003-2005

Source: SCA 2005

134 Audit of the Sydney D

rinking Water C

atchment 2005

Table 1 – Volume (ML) of water licensed to be extracted for each sub-catchment in the Sydney Drinking Water Catchment and the use of the water extracted

Back

and

Rou

nd

Mou

ntai

n C

reek

Brai

dwoo

d C

reek

Bung

onia

Cre

ek

End

rick

Riv

er

Jerra

battg

ula

Cre

ek

Kang

aroo

Riv

er

Kow

mun

g C

reek

Lake

Bur

rago

rang

Littl

e R

iver

Low

er C

oxs

Riv

er

Mid

Cox

s R

iver

Mid

Sho

alha

ven

Riv

er

Mon

garlo

we

Riv

er

Mul

war

ee R

iver

Nat

tai R

iver

Ner

rimun

ga C

reek

O'H

ares

Cre

ek

Ree

dy C

reek

Upp

er C

oxs

Riv

er

Upp

er N

epea

n R

iver

Upp

er S

hoal

have

n R

iver

Upp

er W

ollo

ndilly

Wer

riber

ri C

reek

Win

geca

rribe

e R

iver

Wol

lond

illy R

iver

Wor

onor

a R

iver

Tota

l

Domestic 0 1 10 0 2 8 0 2 1 0 5 0 3 3 3 2 0 0 1 3 0 9 6 11 12 0 82 Experimental

research 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 3

Farming 0 0 0 0 0 7 0 5 0 0 0 0 0 0 0 0 0 5 0 15 0 0 5 0 5 0 47 Industrial 0 0 2 0 0 11 0 0 0 0 78 0 46 5 76 0 0 1 114 7 0 7 84 177 89 0 697

Industrial – Sand and

gravel 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 84 0 89

Irrigation 1330 124 936 15 374 1089 151 265 0 107 881 61 295 1260 36 277 267 268 119 919 140 1356 1891 1703 3926 52 17842 Mining 0 0 86 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 73 0 0 0 0 0 0 0 159

Pisciculture 0 0 0 0 0 0 0 0 0 0 0 0 9 0 0 0 0 0 2 0 0 0 0 18 0 0 29 Recreation – High security 0 8 0 0 0 0 0 0 0 50 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 59

Recreation – Low security 0 9 0 0 0 8 0 0 0 0 0 0 0 83 0 0 0 0 0 2 0 3 0 0 2 0 107

Stock 0 1 44 0 5 36 0 8 6 0 7 5 5 10 15 4 6 5 6 25 0 65 54 64 65 0 436 Town water

supply 0 360 0 0 0 3650 0 0 0 0 70 0 0 0 0 0 0 0 0 250 0 10200 0 2920 269 0 17719

Total 1330 503 1083 15 381 4809 151 280 7 157 1041 66 358 1361 130 283 273 279 315 1221 140 11640 2040 4894 4455 52 37269 Source: DIPNR 2005

Appendix E 135

Table 2 – Percentage of samples collected in exceedence at lake and reservoir locations for the 2005 Audit period

Code SCA Code Station Name Turbidity

(<10NTU)Conductivity (<30 µS/cm)

pH (6.5–8.5)

Total Al

(<0.055 mg/L)

Total Fe

(<0.3 mg/L)

Total P (<10 µg/L)

Filtered P (<5 µg/L)

Total N (<350 µg/L)

Oxidised N (<10 µg/L)

Ammonia (<10 µg/L)

Dissolved Oxygen

(85–110%)

Chlorophyll-a (<5 µg/L)

A DAV7 Lake Avon at the Upper Avon Valve 3.0 99.5 7.1 24.1 13.2 12.5 6.9 13.1 87.1 45.7 56.4 13.7 C DCA1 Lake Cataract at Dam Wall 3.1 99.5 7.2 24.5 13.2 12.8 7.1 13.5 87.5 45.4 57.2 12.8 D DCO1 Lake Cordeaux at Dam Wall 3.1 99.5 4.7 23.8 12.5 13.1 7.3 12.9 87.9 43.2 57.7 12.9 F DFF6 Lake Fitzroy Falls at Midlake 3.2 99.5 3.9 23.9 11.7 13.5 7.5 11.1 87.9 40.6 57.1 12.0 G DGC1 Lake Greaves at Dam Wall 3.1 99.4 4.0 22.4 10.2 11.9 6.0 9.4 88.1 39.3 57.5 10.9 H DLC1 Lake Lower Cascade at 50m upstream 3.2 100.0 3.7 20.9 8.9 12.0 6.1 9.5 88.8 38.3 58.0 10.1 I DNE2 Lake Nepean at 300m upstream of Dam Wall 3.2 100.0 3.8 21.2 9.1 12.3 6.3 9.7 88.8 37.9 58.4 10.2 K DTA1 Lake Yarrunga at 100m from Dam Wall 3.4 100.0 3.8 21.7 9.5 12.6 6.5 9.0 88.2 38.2 59.3 10.2

L DTA3 Lake Yarrunga at Kangaroo River and Yarrunga Junction 17.8 100.0 2.8 66.7 90.9 77.3 56.1 81.8 87.9 78.7 82.0 31.8

M DTA5 Lake Yarrunga at Shoalhaven River 3.0 100.0 3.9 19.0 6.1 10.5 4.7 6.6 88.1 35.3 58.7 9.0 N DTA8 Lake Yarrunga at Kangaroo River, Bendeela PS 2.6 100.0 4.0 18.2 5.3 9.8 4.2 5.9 88.3 34.2 58.6 9.0 O DTA10 Lake Yarrunga at Kangaroo arm, Reed Island 3.2 100.0 3.8 19.9 7.2 11.5 5.7 7.3 88.2 36.6 58.9 10.2 P DTC1 Lake Top Cascade at 100m upstream of Dam Wall 2.5 100.0 4.0 17.3 4.1 8.7 3.1 5.8 88.2 33.5 58.8 7.8 Q DWA2 Lake Burragorang at 500m upstream of Dam Wall 1.9 100.0 4.7 16.5 3.5 9.1 3.3 5.7 88.1 32.3 59.7 7.8 R DWA9 Lake Burragorang at 14km upstream of Dam Wall 0.9 100.0 9.9 21.4 5.3 11.8 5.8 11.8 85.4 40.6 48.0 10.8 S DWA12 Lake Burragorang at 9km upstream of Coxs River 2.5 100.0 4.1 17.7 3.6 8.8 3.1 5.1 88.9 31.1 59.4 7.5 T DWA19 Lake Burragorang at Kedumba River arm 1.9 100.0 4.7 16.9 4.1 9.7 3.8 5.8 88.3 33.5 59.6 8.4

U DWA21 Lake Burragorang at Coxs Arm 37km upstream of Dam Wall 2.4 100.0 7.0 22.5 5.3 13.3 4.8 8.3 85.3 37.8 50.6 10.8

V DWA27 Lake Burragorang at Wollondilly Arm 23 km upstream of Dam Wall 2.4 100.0 7.1 22.0 4.3 12.1 3.8 8.2 86.1 36.1 50.7 10.0

W DWA39 Lake Burragorang at Wollondilly Arm 40 km from Dam Wall 2.0 100.0 9.7 27.0 6.2 18.1 5.9 12.2 86.3 38.8 46.8 15.2

X DWI1 Wingecarribee Lake at outlet 1.8 100.0 22.5 39.8 13.2 28.8 14.9 28.8 84.8 63.1 22.7 33.3 Y DWO1 Lake Woronora at Dam Wall 0.2 100.0 25.5 23.4 2.0 0.5 0.0 1.5 86.7 52.7 22.3 3.9

AF RPR1 Lake Prospect at Midlake 0.0 100.0 0.0 3.7 3.6 0.9 0.0 2.7 7.1 20.4 23.3 6.0 AG RPR3 Lake Prospect near RWPS 0.0 100.0 0.0 14.3 0.0 3.6 0.0 0.0 0.0 20.0 9.3 8.0

Source: SCA 2005 Notes: pH and dissolved oxygen percentage indicates outside guideline range. ANZECC and ARMCANZ 2000 guideline values in parenthesises. Red cells indicate 75–100%, orange 50–75% and yellow 25–50% exceedence of guidelines.

136 Audit of the Sydney D

rinking Water C

atchment 2005

Table 3 – Percentage of samples collected in exceedence at catchment locations for the 2005 Audit period

Code SCA Code Station Name Turbidity

(<15NTU)Conductivity (<350 µS/cm)

pH (6.5-8.5)

Total Al (<0.055 mg/L)

Total Fe (<0.3 mg/L)

Total P (<20 µg/L)

Filtered P (<15 µg/L)

Total N (<250 µg/L)

Oxidised N (<15 µg/L)

Ammonia (<13 µg/L)

Dissolved Oxygen (85-

110%)

Chlorophyll-a (<5 µg/L)

CA E083 Coxs River at Kelpie Point 9.9 0.0 3.8 42.9 11.1 23.1 3.0 30.8 20.7 18.2 7.7 0.0

CB EI30 Kowmung River at Cedar Ford 2.9 0.0 0.0 24.1 5.1 16.7 2.7 35.7 37.5 18.4 7.7 8.1

CC EI57 Kedumba River at Maxwells Crossing 38.7 0.0 0.0 31.6 13.2 23.3 0.0 79.1 97.1 31.4 19.2 2.9

CD E203 Gibbergunyah Creek at Mittagong STP 15.4 69.2 0.0 95.8 8.3 100.0 95.8 100.0 100.0 100.0 84.0 18.2

CE E206 Nattai River at The Crags 44.3 55.0 3.7 34.2 7.9 94.7 94.4 100.0 100.0 56.8 14.8 8.8

CF E210 Nattai River at Smallwoods Crossing 22.2 22.2 0.0 84.2 0.0 36.8 0.0 94.7 68.4 78.9 47.1 42.1

CG E243 Little River at Fireroad 0.0 0.0 11.5 46.2 0.0 0.0 0.0 19.2 92.0 80.8 23.1 7.7

CH E332 Wingecarribee River at Berrima 33.3 0.0 6.4 93.9 51.0 100.0 14.3 100.0 100.0 93.9 22.9 100.0

CI E409 Wollondilly River at Murrays Flat 23.5 90.9 25.9 16.0 13.8 100.0 100.0 100.0 73.9 93.9 70.4 70.0

CJ E450 Wollondilly River at Golden Valley 13.2 100.0 14.3 28.0 39.3 60.7 15.4 100.0 54.5 32.0 23.8 56.0

CK E457 Mulwarree River at Towers Weir ND ND ND ND ND ND ND ND ND ND ND ND

CL E488 Wollondilly River at Jooriland (Fowlers Flat) 10.4 6.0 0.0 94.7 15.8 40.4 3.6 93.0 82.1 35.7 13.7 53.6

CM E531 Werriberri Creek at Werombi 2.0 58.4 10.7 43.8 51.6 2.9 0.0 34.3 51.7 62.1 64.0 3.4

CN E601 Nepean River at Inflow to Lake Nepean ND ND ND ND ND ND ND ND ND ND ND ND

CO E602 Burke River at inflow to Lake Nepean 1.4 0.0 22.2 55.0 100.0 5.0 0.0 15.4 15.4 13.5 14.8 0.0

CW E697 Nepean River 0.0 0.0 0.0 61.8 38.2 29.4 0.0 82.4 100.0 61.8 21.9 52.9

CP E706 Kangaroo River at Hampden Bridge 22.6 0.0 3.7 45.7 43.5 32.6 11.1 43.5 60.0 40.9 11.1 20.5

CQ E822 Mongarlowe River at Mongarlowe 14.3 0.0 11.1 66.7 42.4 12.1 9.1 18.2 37.5 30.3 30.8 3.0

CR E847 Shoalhaven River at Fossickers Flat 55.7 0.0 0.0 100.0 66.7 53.3 11.1 73.3 42.9 11.1 0.0 11.1

CS E851 Shoalhaven River at downstream Tallowa Dam 0.0 0.0 7.4 89.7 20.7 3.4 0.0 100.0 93.1 79.3 3.7 10.3

CT E860 Shoalhaven River at Mount View 17.9 0.0 0.0 35.0 35.0 19.5 17.5 31.7 0.0 30.0 3.8 7.5

CU E861 Shoalhaven River at Hillview 27.3 0.0 19.2 57.5 27.5 20.0 0.0 42.5 25.0 34.2 12.0 21.1

CV E891 Gillamatong Creek at Braidwood 14.3 100.0 3.8 81.8 44.4 58.3 7.4 100.0 87.5 22.2 76.0 25.9

CY GO515 Woronora River at the Neddles 3.8 0.0 0.0 34.5 0.0 3.4 0.0 10.3 33.3 20.7 7.7 0.0 Source: SCA 2005 Notes: pH and dissolved oxygen percentage indicates outside guideline range. ANZECC and ARMCANZ 2000 guideline values in parenthesises

Red cells indicate 75–100%, orange 50–75% and yellow 25–50% exceedence of guidelines

Appendix E 137

Table 4 – Change from the 2003 Audit Report for water quality parameter groups

Code SCA Code Phy Tox Nut Chlor & DO CA E083 | - - | CB E130 | | | + CC E157 - | | | CD E203 + | | | CE E206 + - | | CF E210 - - | | CG E243 | + - | CH E332 | | | | CI E409 | | | + CJ E450 | | | - CL E488 + - | - CM E531 | + + + CO E602 - | - | CP E706 | + - | CQ E822 | | | - CR E847 - - - | CS E851 + | | | CT E860 | + | | CU E861 - | | | CV E891 | + + | A DAV7 - | - | C DCA1 - + | | D DCO1 - + | | F DFF6 - + | + G DGC1 - + - - H DLC1 - | | - I DNE2 - | | | K DTA1 - + | | L DTA3 - | | | M DTA5 - + | | N DTA8 - + | | O DTA10 - + | | P DTC1 - | | - Q DWA2 - | - | R DWA9 - | - + S DWA12 - | - | T DWA19 - + - | U DWA21 - + - - V DWA27 - | - | W DWA39 - + - - X DWI1 - + | + Y DWO1 - + | +

AF RPR1 - | | | AG RPR3 - | | | CY GO515 CW E697

Note: Red cells indicate 75–100%, orange 50–75% and yellow 25–50% exceedence of guidelines

- = increased percentage exceedence from 2003 audit period, + = decreased percentage exceedence from 2003 Audit period and | = no change from 2003 Audit period

138 Audit of the Sydney Drinking Water Catchment 2005

Table 5 – DEC Code (water quality and macroinvertebrate), SCA Code and site description WQ Code Macro Code SCA Code Site Description

A DAV7 Lake Avon at the Upper Avon Valve B DBP1 Bendeela Pondage C DCA1 Lake Cataract at Dam Wall D DCO1 Lake Cordeaux at Dam Wall E DFF Fitzroy Falls composite F DFF6 Lake Fitzroy Falls at Midlake G DGC1 Lake Greaves at Dam Wall H DLC1 Lake Lower Cascade at 50m upstream I DNE2 Lake Nepean at 300m upstream of Dam Wall J DPAE Bendeela picnic area K DTA1 Lake Yarrunga at 100m from Dam Wall L DTA3 Lake Yarrunga at Kangaroo and Yarrunga Junction M DTA5 Lake Yarrunga at Shoalhaven River N DTA8 Lake Yarrunga at Kangaroo River, Bendeela PS O DTA10 Lake Yarrunga at Kangaroo arm, Reed Island P DTC1 Lake top Cascade at 100m upstream of Dam Wall Q DWA2 Lake Burragorang at 500m upstream of Dam Wall R DWA9 Lake Burragorang at 14km upstream of Dam Wall S DWA12 Lake Burragorang at 9km upstream of Coxs River T DWA19 Lake Burragorang at Kembula River arm U DWA21 Lake Burragorang at Coxs arm 37 km upstream of Dam Wall V DWA27 Lake Burragorang at Wollondilly arm 23 km upstream of Dam Wall W DWA39 Lake Burragorang at Wollondilly arm 40 km upstream of Dam Wall X DWI1 Wingecarribee Lake at outlet Y DWO1 Lake Woronora at Dam Wall Z HBP HBP1 and HBP2 taps

AA HFF4 NPWS picnic shelter tap at Fitzroy Falls AB HOP6 Oberon pipeline, Leura AC HPR1 Upper Canal at Prospect WFP AD HUC1 Upper Canal at Broughtons Pass AE HUC3 Upper Canal at Kenny Hill AF RPR1 Lake Prospect at Midlake AG RPR3 Lake Prospect near RWPS AH COMP1,COMP3 Prospect WFP AI COMP5 Illawarra System AJ COMP6 Blue Mountains System AK DNE7 Lake Nepean AL DWI3 Lake Wingecarribee at Midlake AM DWI Lake Wingecarribee composite

Appendix E 139

Table 5 – DEC Code (water quality and macroinvertebrate), SCA Code and site description (Continued)

WQ Code Macro Code SCA Code Site Description MA A5 Mulwaree River at Lake Bathurst MB A6 Tarlo River at Tarlo OT A8 Bungonia Creek at Bungonia OV A16 Coxs River at Lidsdale

CA E083 Coxs River at Kelpie Point MC E086 Coxs River at Kelpie Point

CB MD E130 Kowmung River at Cedar Ford CC ME E157 Kedumba River at Kedumba crossing CD E203 Gibbergunyah Creek at Mittagong STP CE MF E206 Nattai River at The Crags CF MG E210 Nattai River at Smallwoods Crossing CG E243 Little River at Fireroad CH E332 Wingecarribee River at Berrima CI MH E409 Wollondilly River at Murrays Flat CJ E450 Wollondilly River at Golden Valley CK MI E457 Mulwaree River at The Towers CL MJ E488 Wollondilly River at Jooriland CM E531 Werriberri Creek at Werombi CN E601 Nepean River at Inflow to Lake Nepean CO E602 Burke River at inflow to Lake Nepean

MK E6133 Goondarin Creek at top of Cordeaux Dam CW E697 Nepean River CP ML E706 Kangaroo River at Hampton Bridge CQ MM E822 Mongarlow River at Mongarlowe

MN E8311 Corang River at Meangora MO E8361 Nerrimunga Creek at Minshall Trig

CR MP E847 Shoalhaven River at Fossikers Flat CS E851 Shoalhaven River at downstream Tallowa Dam CT OQ E860 Shoalhaven River at Mount View CU MQ E861 Shoalhaven River at Hillview

MR E890 Boro Creek at Marlowe CV MS E891 Gillamatong Creek at Braidwood CY MT GO515 Woronora River at the Neddles

OG Mong1 Mongarlowe River at Charleyong OH N935 Nepean River at Pheasents Nest OI R13 Mongarlowe River at Monga OJ R21 Waratah Rivulet at Flat Rock crossing OK R7 Mulloon Creek at Tawarri OL R8 Currembene Creek at Krawaree Rd crossing OM Reed1 Reddy Creek at Mayfield Rd

140 Audit of the Sydney Drinking Water Catchment 2005

Table 5 – DEC Code (water quality and macroinvertebrate), SCA Code and site description (Continued)

WQ Code Macro Code SCA Code Site Description ON U10 Wingecarribee River at Berrima OO Uwol1 Wollondilly River at Baw Baw Bridge OP Winge2 Wingecarribee River at Greenstead MMP01 Tonalli River up/st Yerrandrie MU MMP02 Tonalli River upstream of Basin Creek MV MMP03 Werriberri Creek at Serenity Park MW MMP04 Blue Gum Creek along fire trail W41 MX MMP05 Little River at fire trail W41 MY MMP06 Shoalhaven River at Yarra Glen MZ MMP07 Jinden Creek at Jinden Ridge Rd NA MMP08 Boggy Creek upstream of Shoalhaven River NB MMP09 Jerrabattgulla Creek at Warragandra NC MMP10 Shoalhaven River at Berlang OU MMP11 Titringo Creek at High Forest ND MMP12 Endrick River at Nerriga NE MMP14 Kowmung River at Kowmung fire trail MMP15 Tuglow River @ Tuglow Forest Rd NF MMP16 Witts Creek at Krawaree Rd crossing NG MMP17 Shoalhaven River at Farrington crossing NH MMP18 Back Creek at Wallace Gap Rd NI MMP19 Bombay Creek at Bombay fire trail NJ MMP20 Nepean River at Maguires crossing NK MMP27 Wollondilly River at Goonagulla NL MMP30 Black Bobs Creek at Bunny Galore NM MMP32 Durran Durra Creek at Euradux OS MMP33 Kings Creek upstream Boro Creek NN MMP34 Boro Creek at Lower Boro NO MMP36 Cedar Creek at Hayes crossing NP MMP37 Coxs River at McKanes Bridge NQ MMP38 Farmers Creek at Great Western Highway NR MMP39 Woodford Creek at Woodford Dam NS MMP40 Yosemite Creek upstream of Minnihaha Falls NT MMP41 Kedumba River at Scenic Railway NU MMP42 Brogers Creek at Priddles Lane crossing NV MMP43 Kangaroo River at Upper Kangaroo NW MMP45 Werriberri Creek at top of Warragamba NX MMP48 Jerrara Creek at Jerrara Rd NY MMP50 Wollondilly River at Gundowringa NZ MMP51 Jacqua Creek at Lumley Rd

Appendix E 141

Table 5 – DEC Code (water quality and macroinvertebrate), SCA Code and site description (Continued)

WQ Code Macro Code SCA Code Site Description OA MMP52 Nadgigomar Creek at Oallen Ford OB MMP53 Woronora River at Eckersley Ford OC MMP55 Little River at Six Foot Track OD MMP56 Jenolan River at Camping Area OE MMP57 Werriberri Creek at The Oaks OF MMP58 Little River at Buxton OR MMP76 Leura Falls Creek at FT W74 A1 Witts Creek A10 Sooly Creek A11 Coxs R A12 Kings Ck A13 Brogers ck A14 Jerrabattagulla Ck A15 Nadgigomar Ck OV A16 Coxs River at Lidsdale A2 Upper Shoalhaven R A3 Reedy Ck A4 Upper Mongarlowe R MA A5 Mulwaree River at Lake Bathurst MB A6 Upper Tarlo River at Tarlo A7 Woolshed Ck OT A8 Bungonia Ck at Bungonia A9 Heffernans Ck R1 Nepean R R10 Heathcoate Ck R12 Nattai R OI R13 Upper Mongarlowe R at Monga R16 Little R R17 Wollondilly R R18 Guineacor Ck OJ R21 Waratah Rivulet at Flat Rock crossing R22 Kowmung R R4 Endrick R R6 Reedy Ck OK R7 Mulloon Ck at Tawarri OL R8 Currumbene Ck at Krawaree Rd crossing U10 Wingecarribee R U11 Wollondilly R U12 Mulwaree R U2 Mittagong Ck

142 Audit of the Sydney Drinking Water Catchment 2005

Table 5 – DEC Code (water quality and macroinvertebrate), SCA Code and site description (Continued) WQ Code Macro Code SCA Code Site Description

U3 Katoomba ck U4 Gibbergunyah Ck U5 Nattai R U6 Farmers Ck U7 Gillamatong Ck U8 Paddys R U9 Forbs Ck

Appendix E 143

Table 6 – Code, SCA Code and macroinvertebrate Ausrivas band for the 2003 and 2005 Audit periods

Code SCA Code Edge Riffle Combined 2001 2002 2003 2004 2001 2002 2003 2004 2001 2002 2003 2004

MA A5 A A A - - - - - - - - - MB MMP30 - A - - - - - - - - - - MC E086 X A A A X A A A X A A A MD E130 - A A A - A A A - A A A ME E157 A A A A A X A X A A A A MF E206 A A A A A A A A A A A A MG E210 - A A A - - A B - - A B MH E488 - A A OEM - B - - - B - - MI E457 B C A B - - - - - - - - MJ A6 A B B C - - - - - - - - MK E6133 - B - - - - - - - - - - ML E706 A A A A A A A A A A A A MM E822 - A - - - - - - - - - - MN E8311 OEM A X A B - - - NRA - - - MO E8361 B A B A - - - - - - - - MP E847 B A B A - B A B - B B B MQ E861 A A A B A A B A A A B B MR E890 A B A B - - - - - - - - MS E891 B B B B - - - - - - - - MT GO515 B B A C A A B - B B B - MU MMP02 - B B B - - - - - - - - MV MMP03 - A A B - - A A - - NRM B MW MMP04 - B A B - - - - - - - - MX MMP05 - B A A - A A - - B A - MY MMP06 X A A X B B A B B B A NRA MZ MMP07 - - - - - - - - - B - - NA MMP08 - A OEM A - - - - - - - - NB MMP09 A A B X - - - - - - - - NC MMP10 - - - - - - - - - A - - ND MMP12 OEM A A A A - B A NRA - B A NE MMP14 A A B X X A A B A A B NRA NF MMP16 B A A B A A B B B A B B NG MMP17 A A A A A A A B A A A B NH MMP18 - A - - - - - - - - - - NI MMP19 - A - - - - - - - - - - NJ MMP20 - A B A - - - A - - - A NK MMP27 X A A X - - - - - - - - NL E409 - B - - - - - - - - - - NM MMP32 - B - - - - - - - - - - NN MMP34 - A - - - - - - - - - - NO MMP36 - B - - - - - - - - - - NP MMP37 A A A A X B A A A B A A NQ MMP38 - - - - - - - - - C - -

144 Audit of the Sydney Drinking Water Catchment 2005

Table 6 – Code, SCA Code and macroinvertebrate Ausrivas band for the 2003 and 2005 Audit periods (Continued)

Code SCA Code Edge Riffle Combined 2001 2002 2003 2004 2001 2002 2003 2004 2001 2002 2003 2004

NR MMP39 A B A A - - - - - - - - NS MMP40 A C B A A - - - A - - - NT MMP41 C C - - - - - - - - - - NU MMP42 - - - - - - - - - B - - NV MMP43 B A B A A A A A B A B A NW MMP45 - B - - - - - - - - - - NX MMP48 - A - - - - - - - - - - NY MMP50 - A - - - - - - - - - - NZ MMP51 A A C B - - - - - - - - OA MMP52 - A - - - - - - - - - - OC MMP55 X A A A A B A A A B A A OD MMP56 - - - - - - - - - B - - OE MMP57 A A A C - - - - - - - - OF MMP58 - B - - - - - - - - - - OG Mong1 A A A A A A B A A A B A OH N935 - - A A - - B B - - B B OI R13 X A X A X A A X X A A A OJ R21 A A B B C - - - C - - - OK R7 A A B B - - C - - - C - OL R8 B A A A A A B - B A B - OM Reed1 A A A A - - A B - - A B ON U10 C B B B B - C B C - C B OO Uwol1 A A A B - - - - - - - - OP Winge2 A A A A A A B A A A B A OQ E860 OEM X A A B A B A NRA A B A OR MMP76 - - A B - - - A - - - B OS MMP33 A - A A - - - - - - - - OT A8 B - B B - - - - - - - - OU MMP11 A OEM A A - - - - - - - - OV A16 A X A A A B A A A B A A

Source: Ecowise 2005 Note: Lavender = Richer assemblage than AusRivAs reference condition; Green = Similar to AusRivAs reference location; Yellow = Significantly impaired; Red = Severely impaired. OEM = outside experience of model, no assessment can be made of the site; NRA = No Reliable Assessment could be made of the site

Appendix E 145

Table 7 – Location description of sites used in the Delta Coxs River Fish study

Site Code Location Description CR1 Coxs River upstream of Lake Lyell

EFR2 Coxs River downstream of Lake Lyell

EFR3 Coxs River downstream of Lake Lyell at McKanes Bridge

EFR4 Coxs River downstream of Lake Lyell at Glenroy Bridge RR5 Coxs River downstream of Lake Lyell at Lithgow Gauge

Source: Delta 2005