Perth and Peel Green Growth Plan for 3.5 Million

Government of Western Australia Department of the Premier and Cabinet

Perth and Peel Green Growth Plan for 3.5 million Strategic Assessment of the Perth and Peel Regions Draft EPBC Act Strategic Impact Assessment Report Part D: MNES Assessment$IBQUFS December 2015

Acknowledgements This document has been prepared by Eco Logical Australia Pty Ltd and © Government of Western Australia Open Lines Consulting. Department of the Premier and Cabinet Disclaimer Dumas House This document may only be used for the purpose for which it was 2 Havelock Street commissioned and in accordance with the contract between Eco Logical Australia Pty Ltd and the Department of the Premier and West Perth WA 6005 Cabinet. The scope of services was defined in consultation with the Department of the Premier and Cabinet, by time and budgetary Website: www.dpc.wa.gov.au/greengrowthplan constraints imposed by the client, and the availability of reports Email: [email protected] and other data on the subject area. Changes to available information, legislation and schedules are made on an ongoing Tel: 08 6552 5151 basis and readers should obtain up to date information. Fax: 08 6552 5001

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Strategic Assessment for the Perth and Peel Regions

Contents

List of Figures ...... ii

List of Tables ...... iii

19 Wetlands of international importance (Ramsar) ...... 19-1 19.1 Summary ...... 19-1 19.2 Introduction ...... 19-4 19.3 Conservation outcome ...... 19-6 19.4 Baseline information for Ramsar ...... 19-6 19.5 Impact assessment approach for Ramsar ...... 19-7 19.6 Monitoring ...... 19-22 19.7 Becher Point Wetlands ...... 19-23 19.8 Forrestdale and Thomsons Lakes ...... 19-37 19.9 The Peel-Yalgorup System ...... 19-58

List of Figures

Figure 19-1: Location of Becher Point, Forrestdale and Thomsons Lakes, and Peel- Yalgorup Ramsar sites ...... 19-5

Figure 19-2: Becher Point Ramsar site ...... 19-25

Figure 19-3: Forrestdale and Thomsons Lake Ramsar site ...... 19-39

Figure 19-4: Phosphorus Risk for Urban, Industrial and Rural Residential Expansion areas within 5km of Forrestdale and Thomsons Lakes ...... 19-50

Figure 19-5: Peel-Yalgorup System Ramsar site ...... 19-60

Figure 19-6: Relative land use areas and nitrogen and phosphorus loads flowing to the Peel-Harvey Estuary from the coastal plain portion of the catchment ...... 19-74

Figure 19-7: Phosphorus Risk for Urban, Industrial and Rural Residential Expansion areas within the Peel-Harvey and Yalgorup Catchments ...... 19-79

Figure 19-8: Framework for State and MNES commitments for the Peel-Yalgorup Ramsar site ...... 19-84

Strategic Assessment for the Perth and Peel Regions

List of Tables

Table 19-1: Condition and trend ratings for LACs ...... 19-7

Table 19-2: Projected population estimates ...... 19-15

Table 19-3: Risk rating table ...... 19-17

Table 19-4: Consequence table for Ramsar risk assessment ...... 19-20

Table 19-5: Need for Ramsar monitoring ...... 19-22

Table 19-6: Ramsar listing criteria and justification for Becher Point Wetlands ...... 19-24

Table 19-7: Summary of the condition against each of the LACs for Becher Point Wetlands ...... 19-27

Table 19-8: Existing and proposed development around Becher Point Ramsar site ...... 19-29

Table 19-9: Summary of groundwater risk assessment for Becher Point Ramsar site ...... 19-30

Table 19-10: Summary of people pressure risk assessment for Becher Point Ramsar site ...... 19-33

Table 19-11: Ramsar listing criteria and justification for Forrestdale and Thomsons Lakes ...... 19-38

Table 19-12: Summary of the condition against each of the LACs for Forrestdale and Thomson Lakes Wetlands ...... 19-41

Table 19-13: Existing and proposed development around Forrestdale and Thomsons Lakes Ramsar site ...... 19-44

Table 19-14: Summary of groundwater risk assessment for the Forrestdale and Thomsons Lakes Ramsar site ...... 19-46

Table 19-15: Summary of people pressure risk assessment for Forrestdale Lake ...... 19-51

Table 19-16: Summary of people pressure risk assessment for Thomsons Lake ...... 19-52

Table 19-17: Summary of existing management arrangements for the Peel-Yalgorup System Ramsar site ...... 19-62

Table 19-18: Ramsar listing criteria and justification for the Peel-Yalgorup System ...... 19-64

Table 19-19: Summary of the condition against each of the LACs for the Peel Yalgorup System Ramsar site ...... 19-67

Table 19-20: Existing and proposed development areas in the Peel-Harvey and Yalgorup catchments ...... 19-72

Table 19-21: Summary of groundwater risk assessment for the Peel-Harvey subarea of the Peel-Yalgorup Ramsar site ...... 19-75

Table 19-22: Summary of groundwater risk assessment for the Yalgorup Lakes subarea of the Peel-Yalgorup Ramsar site ...... 19-76

Table 19-23: Summary of people pressure risk assessment for Peel-Yalgorup Ramsar site ...... 19-81

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Strategic Assessment for the Perth and Peel Regions

Table 19-24: Package of commitments to address both the legacy issues and future risks from the classes of action ...... 19-95

Strategic Assessment for the Perth and Peel Regions

19 Wetlands of international importance (Ramsar)

19.1 SUMMARY

There are three Ramsar sites within the Strategic Assessment Area. They are:

 the Peel-Yalgorup System of wetlands;

 Becher Point Wetlands; and

 Forrestdale and Thomsons Lakes.

The locations of these wetlands are shown in Figure 19-1.

None of the sites will be directly impacted by the proposed classes of action. However, all three are currently affected by a range of pressures or 'legacy' issues, and may be subject to additional indirect impacts from the classes of action.

The conservation outcomes for Ramsar are to maintain and where possible improve their ecological character in accordance with Australia’s obligations under the Ramsar Convention (see Section 19.3). This outcome is expected to be met for all three sites under the Strategic Conservation Plan.

19.1.1 Impacts

The key indirect impacts across the three sites relate to potential:

 changes to groundwater and/or surface water; and

 impacts from increased human use of or residence around wetlands.

Peel-Yalgorup System

The most important and complex set of potential impacts relate to the Peel-Yalgorup System. This site is spread over two major catchment systems and supports a wide range of ecological, social and economic values. Each major catchment is already subject to a number of pressures or legacy issues.

These legacy issues are the dominant factors in the health of the system and at a high level include:

 Threats to water quality at a catchment scale - particularly through increasing nutrients within the catchment from a range of sources including agriculture, horticulture and rural residential development.

 Decreasing inflows to the wetlands – due to a number of factors including decreased rainfall, increased evaporation, groundwater abstraction, and land use change.

 Increasing people pressures – due to a range of activities associated with the existing population.

 Altered tidal regime in the Peel inlet – due to the construction of the Dawesville channel.

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Strategic Assessment for the Perth and Peel Regions

In addition to the legacy issues, the proposed classes of action will lead to a set of future pressures and risks. While these are considered to be of a lower magnitude than the catchment scale pressures, it is critical that they are mitigated and managed appropriately. Potential future pressures and risks from the classes of action include:

 Threats to water quality at a local scale related to proposed new development – due to a range of potential sources including construction, vegetation clearing, increased developed area, and septic tanks and ATUs.

 Decreasing inflows to the Yalgorup lakes – due to potential groundwater abstraction from rural residential development.

 Increasing people pressures - due to a range of activities associated with the growing population.

Becher Point Wetlands

Becher Point Wetlands is at risk from a reduction in groundwater quantity and quality due to groundwater abstraction and increasing people pressures.

Forrestdale and Thomsons Lakes

Forrestdale and Thomsons Lakes are at risk from a reduction in groundwater quantity due to groundwater abstraction, groundwater quality from nearby construction, and increasing people pressures.

19.1.2 Commitments

The Strategic Conservation Plan (and supporting action plans) provides a package of commitments for the three Ramsar sites to address both the legacy issues and future risks from the classes of action. It does this through:

 A set of State commitments in Action Plan G to address the legacy issues.

 A set of MNES commitments in Action Plan F to address the risks from the classes of actions.

Peel-Yalgorup System

A range of conservation commitments are proposed to maintain and improve the condition of the Peel-Yalgorup System of wetlands. These relate to management activities and policies across the Peel-Harvey and Yalgorup catchments, including:

 establishment of the Peel Regional Park;  expansion of Yalgorup National Park;

 ongoing management of groundwater resources;

 measures to improve water quality (incorporated into Action Plan G) including mandatory soil testing, drainage interventions, and promotion of the use of soil products;

 updating relevant planning and environmental protection policies to address future changes in landuse; and

 monitoring of the Limits of Acceptable Change.

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These measures will address groundwater availability, nutrient inputs, and recreational use.

Forrestdale and Thomsons Lakes & Becher Point Wetlands

A simpler set of conservation commitments are proposed for Forrestdale and Thomsons Lakes and Becher Point Wetlands. These are focused on using a whole of catchment management approach to improve and maintain the health of the sites.

The commitments include measures to:

 manage access and use of the sites;

 ongoing management of groundwater resources;

 monitoring of the Limits of Acceptable Change; and

 investigate stormwater supplementation at Forrestdale Lake.

19.1.3 Outcomes

The package of conservation commitments across both Action Plans G and F are considered sufficient to ensure acceptable outcomes for each Ramsar site within the context of the EPBC Act. The design of the classes of action and implementation of conservation commitments will mean that the conservation objectives for each site will be achieved.

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19.2 INTRODUCTION

Wetlands of international importance include wetlands designated under Article 2 of the Ramsar Convention or declared by the Commonwealth Minster for the Environment to be a declared Ramsar wetland under the EPBC Act.

There are three Ramsar wetlands within the Strategic Assessment Area that may be impacted by future development in the Perth and Peel Regions. These include:

 Becher Point Wetlands;

 Forrestdale and Thomsons Lakes; and  the Peel-Yalgorup System of wetlands.

The location of these sites is shown in Figure 19-1.

This Chapter provides the conservation outcome for Ramsar, outlines the methodology used to assess impacts and define mitigation and management measures, and provides an impact assessment of each Ramsar site. It also:

 provides a brief introduction to each of the three wetlands, which is supported by a detailed condition statement for each site (Appendix D);

 defines conservation objectives for each of the wetlands and describes the Limits to Acceptable Change (LAC) that have been established for each site; and

 considers potential impacts to Ramsar values from the relevant classes of action and identifies practical mitigation and management measures (in the form of conservation commitments) to minimise impacts of the classes of action.

The Chapter is structured as follows:

 Section 19.3 – provides the conservation outcome for Ramsar.  Section 19.4 – summarises the baseline information used in the assessment.

 Section 19.5 – describes the methodology used to assess impacts to each Ramsar site.

 Section 19.6 – provides an overview of the Ramsar monitoring needs.  Section 19.7 – addresses the Becher Point wetlands.

 Section 19.8 – addresses Forrestdale and Thomson Lakes.

 Section 19.9 – addresses the Peel-Yalgorup System of wetlands.

Ramsar wetlands often provide habitat for threatened and migratory species listed under the EPBC Act, and can also support Threatened Ecological Communities (TECs). Where the three Ramsar wetlands support these values, discussion and assessment is provided in Chapters 18 and 20 as this chapter solely focuses on identifying, assessing and mitigating impacts to Ramsar values.

19-4

Figure 19-1: Location of Becher Point, Forrestdale and Thomsons Lakes, and Peel-Yalgorup Ramsar Sites Central

Kwinana !H

Rockingham !H

Jarrahdale !H

Serpentine !H

Mandurah !H

South Metro Peel

Pinjarra !H

Dwellingup !H

Waroona !H

Legend

Strategic Assessment Area Ramsar Wetland Sub- group: Becher Point 0 10 20 Wetlands Kilometres Datum/Projection: Forrestdale & GDA 1994 MGA Zone 50 Thomsons Lakes Data Source: DPaW Peel-Yalgorup System Prepared by: JL Date: 19/11/2015 ± Strategic Assessment for the Perth and Peel Regions

19.3 CONSERVATION OUTCOME

The conservation outcome for Ramsar is:

The ecological character of wetlands of international importance within the Perth and Peel regions is maintained and where possible improved. Measures and actions are consistent with Australia’s obligations under the Ramsar Convention.

“Ecological character” is a key concept in relation to Ramsar sites. It provides a baseline description of a wetland at a given point in time and is used as part of the impact assessment process under the EPBC Act.

The conservation outcome is included in the Strategic Conservation Plan and was developed based on the over-arching aims and principles of the Ramsar convention and Australia’s associated international obligations. It is a key component to the protection of MNES and forms the highest level in the conservation outcomes framework (see Chapter 8).

Guided by this over-arching outcome, more specific conservation objectives were developed for each Ramsar site. These objectives are presented throughout this chapter and are based on the key aspects that define ecological character. Determining the objectives relied heavily on information provided in condition statements for each site (Appendix D).

19.4 BASELINE INFORMATION FOR RAMSAR

This section provides an outline of the resources and methods used in generating the baseline information used for the Ramsar impact assessments. Reference should also be made to the overall description of information for the assessment outlined in Chapter 7.

Baseline information describing the characteristics of each Ramsar site has been prepared in the form of condition statements by WA State Government Agencies. These statements included the following information:

 description of the Ramsar site and discussion of the site’s values;  Ramsar listing criteria;

 current condition (including limits of acceptable change);

 past, existing and future threats; and  management arrangements.

Information from these condition statements has been summarised below for each site. The complete condition statements are available at Appendix D.

A key component of each condition statement is the analysis of limits of acceptable change (LACs). LACs are an important tool to assist in determining both the current condition of Ramsar sites, and also trends in the condition of ecological character over time. Generally, LACs are set for parameters including hydrology, water quality and flora and fauna (native and exotic). Each Ramsar site has LACs which set the boundaries between which the condition of Ramsar site values can fluctuate without concern. When ambient conditions exceed LACs, it provides an indication that changes in the ecological condition of the site may be occurring.

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Strategic Assessment for the Perth and Peel Regions

Summaries of LACs discussed in the condition statements are presented below and provide a good summary of the current condition of each Ramsar site broken down by individual values. The trends in LACs have been used in the impact assessment to provide context to the potential risk from future impacts relative to the current condition of sites.

The relationship between LACs, condition and trend used in this assessment is summarised in Table 19-1.

Table 19-1: Condition and trend ratings for LACs

Condition or trend Relationship to LACs

Excellent condition LAC always met

Good condition LAC met in a majority of years

Moderate condition LAC not met in a majority of years

Poor condition LAC not met since they were established

Improving trend Fewer exceedances of LACs or small magnitude of exceedance over time

Stable trend LACs do not change over time

Degrading trend More exceedances of LACs or larger magnitude of exceedance over time

19.5 IMPACT ASSESSMENT APPROACH FOR RAMSAR

The overall approach to the impact assessment is provided in Part B of the report. In addition to this general approach, a tailored approach to the impact assessment for Ramsar has been developed. This section provides:

 An outline of the impact assessment considerations for Ramsar under the EPBC Act.

 An overview of the impact assessment approach for Ramsar.

 An identification of the activities that may lead to indirect impacts on the Ramsar sites.  An overview of the risk assessment process that has been used to understand potential impacts.

 An overview of the method for defining conservation commitments.

19.5.1 Addressing impacts to Ramsar sites under the EPBC Act

The EPBC Act Significant Impact Guidelines 1.1 provide over-arching guidance for undertaking impact assessment under the Act. The key element for consideration for Ramsar wetlands is the concept of ecological character. This is defined under the Act as “the combination of the ecosystem components, processes and benefits/services that characterise the wetland at the time of designation on the Ramsar List”.

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The Significant Impact Guidelines state that an action is likely to have a significant impact on the ecological character of a declared Ramsar wetland if there is a real chance or possibility that it will result in:

 Areas of the wetland being destroyed or substantially modified.

 A substantial and measurable change in the hydrological regime of the wetland, for example, a substantial change to the volume, timing, duration and frequency of ground and surface water flows to and within the wetland.

 The habitat or lifecycle of native species, including invertebrate fauna and fish species, dependent upon the wetland being seriously affected.

 A substantial and measurable change in the water quality of the wetland – for example, a substantial change in the level of salinity, pollutants, or nutrients in the wetland, or water temperature which may adversely impact on biodiversity, ecological integrity, social amenity or human health.

 An invasive species that is harmful to the ecological character of the wetland being established (or an existing invasive species being spread) in the wetland.

The same key considerations are also reflected in the Australian Ramsar Management Principles. Under this framework, management plans for Ramsar wetlands must contain mechanisms to address risk to a wetland’s ecological character, including measures to respond to:

 physical loss, modification or encroachment on the wetland;

 loss of biodiversity;  pollution and nutrient input;

 changes to water regimes;

 utilisation of resources; and  introduction of invasive species.

19.5.2 Overview of the assessment approach

It is critical to note that none of the three Ramsar sites will be directly impacted by the classes of action. As a consequence, the Ramsar impact assessment focuses on potential indirect impacts or the flow-on pressures brought about by the classes of action.

A set of work was undertaken by WA State Government Agencies to understand potential indirect impacts to the three Ramsar sites. This work involved risk assessments that examined each of the potential impacts from the classes of action.

The approach to undertaking this impact assessment has been to:

 Identify potential indirect impacts stemming from the classes of action.

 Undertake a risk assessment of these potential impacts.  Contextualise the potential impacts in terms of the current ‘baseline’ scenario (noting that all indirect impacts are currently impacting on the Ramsar sites to some degree).

 Evaluate the future pressures, their risk and potential intensity and outcome for Ramsar sites.

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Strategic Assessment for the Perth and Peel Regions

 Understand future pressures and their outcomes in terms of current trends in the condition of ecological character of the sites.

 Use the EPBC Act Significant Impact Guidelines 1.1 to frame the discussion of impacts and outcomes to the ecological character of the Ramsar sites - i.e. consider the following factors:

o destruction or substantial modification to the wetland; o changes to hydrological regime;

o changes to water quality;

o serious effects on the habitat or lifecycle of native species; and o establishment or spread of invasive species.

 Define conservation commitments (in the form of management and mitigation measures to address impacts) to ensure the conservation objectives will be achieved.

It should be noted that climate change impacts are addressed in Chapter 13. However, the conservation commitments for each Ramsar site includes climate change considerations, particularly via commitments around adaptive management and on-going monitoring and research.

19.5.3 Identifying potential indirect impacts

The classes of action that have the potential to indirectly impact the three Ramsar sites are urban, industrial, rural residential and infrastructure. While there are a range of issues associated with historical impacts to wetlands within the Perth and Peel regions (e.g. water quality issues), this impact assessment focuses on the future risks from the classes of action. The historical issues are discussed for context around current pressures and trends.

To structure the assessment, indirect impacts are assessed for each Ramsar site in relation to:

 Changes to the groundwater and/or surface water.  Changes to ecological values of the sites from increases in population (primarily via increased recreational use).

The activities that may lead to these indirect impacts are discussed below.

Changes to ground water and/or surface water

Activities associated with the classes of action with the potential to impact groundwater and surface water resources of the Ramsar sites include:

 Construction - e.g. temporary dewatering, activation of acid sulfate soils, contamination.

 Increased extent of urban, rural residential and industrial areas.

 Alterations to drainage.  Groundwater abstraction, including licensed abstraction for non-potable and potable supply and garden bores, which are exempt from licensing.

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Potential impacts from construction

Indirect impacts from construction can be associated with dewatering, activation of acid sulfate soils and/or introduction of contaminants. State agencies (DoW and DER) provide guidance documents about minimising and managing impacts from these activities.

At this stage, specific locations and scale of dewatering, potential acid sulfate soil activation and/or contaminant risk is not known and impacts to water quantity and quality can only be assumed. However, the duration of construction work is generally likely to be short term, intermittent and in varying locations over the next decades. This will limit the severity of potential impacts from construction to the Ramsar sites.

Dewatering

Temporary dewatering during the construction phase of development most commonly occurs for the installation of underground infrastructure and drainage systems where groundwater is close to the ground surface. It involves abstracting groundwater from construction areas, either from a bore or via an excavation within saturated conditions. Dewatering is generally required in a localised area and has a short duration (weeks) during construction.

Temporary dewatering can impact on the surface and groundwater quantity and quality of receiving environments through:

 reducing water levels (usually a local and temporary decline);

 mobilising nutrients and contaminants;

 increasing acidity by exposing acid sulfate soils and mobilising metals e.g. iron and aluminium;  increasing turbidity or sedimentation; and/or

 increasing salinity.

Treatment of groundwater released through dewatering may be employed to maintain or improve surface or groundwater quality of the receiving environment. Other management methods can be employed to limit the impacts or avoid the need for temporary dewatering.

Activation of acid sulfate soils

Acid sulfate soils are naturally occurring soils, sediments and peats that contain iron sulfides. They are most commonly found in low-lying land bordering the coast and wetland basins. Disturbance of acid sulfate soil, and its exposure to oxygen, can form sulfuric acid resulting in the release of metals, nutrients and acidity into the soil and groundwater system. This has the potential to cause significant environmental and economic impacts including:

 loss of biodiversity including fish kills in wetlands and waterways;

 contamination of groundwater resources by acid, arsenic, heavy metals and other contaminants;  loss of agricultural productivity;

 contamination of drinking water; and/or

 corrosion of concrete and steel infrastructure by acidic soil and water.

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There are regulatory requirements currently in place to ensure acid sulfate soils are appropriately managed during construction, namely Planning Bulletin 64/2009 Acid Sulfate Soils and related Acid Sulfate Soils Planning Guidelines. The Western Australian Planning Commission planning guidelines for acid sulfate soils (WAPC 2008) emphasise avoidance through early planning. The Guidelines indicate:

Where practicable strategies, schemes or amendments proposing any change of zoning that will lead to the introduction of, or an intensification of, development that is likely to result in significant amounts of excavation, drainage, or groundwater extraction on land depicted in either the DEC’s geographic data atlas or Landgate’s shared land information platform’s WA atlas map viewer or Landgate’s interest enquiry service as being wholly or partially within an area of “high to moderate acid sulfate soils” (i.e. depicted in red), should be avoided.

Throughout the planning process further measures in the Guidelines are aimed at ensuring that the potential for acid sulfate soils are adequately investigated and if not avoided, appropriate mitigation measures are established.

The Guidelines indicate (for example) that any structure plan involving land depicted in either the DEC’s geographic data atlas or Landgate’s shared land information platform’s WA atlas map viewer or Landgate’s interest enquiry service as being wholly or partially within an area of “high to moderate acid sulfate soils” (i.e. depicted in red) should address the issue of acid sulfate soils, and include an acid sulfate soils investigation that:

 Determines the likely presence and distribution of acid sulfate soils on the land, or alternatively, the absence of acid sulfate soils, based on at least step 1 of the DEC’s Identification and Investigation of Acid Sulfate Soils guideline.

 Demonstrates the capacity of the land to sustain the pattern and distribution of proposed land uses having regard to:

o the likely extent and severity of acid sulfate soils; o potential impacts on surface and groundwater quality and quantity;

o potential impacts on ecosystems and biodiversity;

o potential impacts on existing land uses in the vicinity; o any likely engineering constraints and impacts on infrastructure; and

o cumulative impacts.

 Where practicable, the pattern and distribution of proposed land uses within the plan area should seek to avoid the introduction, or an intensification, of development that is likely to result in significant amounts of excavation, drainage, or groundwater abstraction on land where the presence of acid sulfate soils has been confirmed by an acid sulfate soils investigation.

At the subdivision and development application stages the Guidelines (WAPC 2008) acknowledge that avoidance might not always be possible (although desirable) and a specific acid sulfate soil investigation and subsequent development of a management plan are required.

Introduction of contaminants

Contaminants can be released into surface and groundwater through:

 spillage or improper application of hazardous materials;

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 inappropriate disposal/management of groundwater derived from construction dewatering; and/or

 run-off from sealed surfaces that may contain oils, greases, heavy metals and other potential contaminants.

Given the generally sandy substrates of the Perth and Peel region, contaminated surface water is readily able to penetrate groundwater supplies. Once groundwater has been contaminated, it can be very expensive and often impossible to remove the pollutant. Natural dilution and dispersion may take hundreds of years. Contamination of groundwater can adversely affect the ecology of groundwater dependent ecosystems and can be a serious issue if groundwater in the area being developed is in a public drinking water source area as the groundwater may become unsuitable for drinking or other uses, or require expensive treatment.

Potential impacts from land use change resulting from removal of vegetation and increased extent of urban, rural residential and industrial areas

Removing vegetation and increasing the extent of urban, rural and industrial areas can have numerous impacts to water resources, including both the introduction of contaminants and nutrients as well as alteration to groundwater levels.

Numerous contaminants and nutrients can enter the surface water and groundwater systems due to increasing development and lead to compromised water quality. Pathways include:

 leaching and runoff of fertilisers, herbicides and pesticides;

 leaking of septic tanks and chemical storages;  runoff from impervious surfaces e.g. roads; and

 incorrect disposal of materials e.g. chemicals (household and commercial), fertilisers, dog faeces, garden waste.

Land clearing can also result in the disturbance and activation of acid sulfate soils and associated metals, and may also lead to salinity problems with alterations to groundwater levels.

In addition to potential impacts to water quality, the removal of vegetation (resulting in less evapotranspiration) and increased areas of urbanised land (where roof and road runoff channel rainwater into soak wells and stormwater basins) can also directly affect groundwater levels. Collectively, this can lead to increases in groundwater levels and surface flows.

Increased groundwater recharge has potential positive and negative impacts to the Ramsar sites. Increasing the static water levels in the superficial aquifer may raise water levels at the Ramsar sites and also has the potential to prevent saltwater intrusion. However, negative impacts include potential waterlogging and contaminated recharge, although these can be partially mitigated by first-flush systems and water sensitive urban design.

State Planning Policy 2.9: Water Resources (WAPC 2006) provides guidance on how water resources should be regarded and managed through the land-use planning system. SPP 2.9 provides recognition of the significant role that the planning system has in providing for total water cycle management. Guidance on the implementation of State Planning Policy 2.9 is provided in Better Urban Water Management (WAPC 2008a). This document provides a framework for how water resources should be considered at each planning stage by identifying the various actions and investigations required to support the particular planning decision being made. The Regional Water Plan provides context and support for these and guidance to the Western Australian Planning Commission (WAPC) on water

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planning priorities. The framework outlined in Better Urban Water Management is intended to be applied to both new greenfield and urban renewal projects where residential, commercial, industrial and rural residential uses and development are proposed (WAPC 2008a).

Better Urban Water Management recognises the Stormwater Management Manual for Western Australia (DoW 2007b) as the key guidance document for management of stormwater in WSUD. The manual was developed in partnership with the Swan River Trust and other stakeholders, advocates the use of WSUD where appropriate providing high-level policies, planning principles, and practical on ground best practice advice in stormwater management.

The Better Urban Water Management framework requires an increasing level of detail of water management planning to be implemented at the various levels of planning. A District Water Management Strategy would be prepared to support a District Structure Plan or Local Planning Scheme addressing the broad principles and approach to be applied for water management including to protect water resources. This gives consideration to catchment and regional scale issues, long term water resource management and planning.

At the next level down, local water management strategies are required to support local structure plans and urban water management plans will be required to accompany the subsequent subdivision or development applications with increasing level of detail on water sensitive urban design management measures to apply. All of these plans/strategies are referred to the Department of Water for formal comment and endorsed as the way forward. This endorsement is required in order for the Western Australian Planning Commission to approve the respective planning scheme, structure plan or planning application.

In addition to impacts to water resources, increased extent of urban, rural residential and industrial areas can also increase the pressure on remnant habitat from plant diseases, weeds (and therefore wildfire incidence) and feral animals and often lead to long-term degradation of these remnant areas.

Potential impacts from alterations to drainage

Urban and industrial developments can require altered drainage to adequately manage runoff and groundwater levels close to infrastructure. Stream diversions and installation of culverts, pipes and channels (either surface or subsurface) have the potential to impact surface and groundwater levels. These may be positive or negative depending on whether a wetland would benefit from more or less water. Additionally, altered drainage may divert contaminated runoff either into or away from wetlands.

Potential impacts from groundwater abstraction

Groundwater abstraction associated with the proposed development has the potential to reduce surface and groundwater levels. This has the potential for direct consequences of reduced water availability, but also indirect consequences such as allowing salt water intrusion into groundwater systems.

The Department of Water is responsible for managing the State's groundwater resources. In most areas of the State, groundwater use must be licensed under the Rights in Water and Irrigation Act 1914 administered by the Department of Water. Licensing is guided by allocation limits that set out how much water is available from a particular resource or area and how much water needs to be left in the system to ensure its sustainability, An allocation limit is an annual volume of water set aside for consumptive use from a water resource. This includes:

 water that is available for licensing;

 water that is exempt from licensing; and 19-13

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 water set aside for future public water supply.

Once an allocation limit is set, water is allocated up to that limit. Once the allocation limit is reached, no more licences are issued and trading is encouraged. Water for the environment is calculated, however not included in the allocation limit because it is left in the system and considered a non-consumptive use.

The future development of the Perth and Peel regions will result in increased demand for groundwater for non-potable supply for purposes including:

 dust suppression during construction;  irrigation of new areas of public open space, schools and playing fields;

 water supply in industrial areas; and

 domestic use in rural residential developments and to a lesser extent, in urban developments.

The future development of the Perth and Peel regions will also increase public (potable) water supply demand. The Water Corporation manages and operates the Integrated Water Supply Scheme (IWSS), which provides scheme water to domestic, industrial and commercial customers in the in the Perth, the Goldfields and Agricultural regions and some parts of the South West. The sources supplying the IWSS are an integrated system consisting of large dams, pipehead dams and pumpbacks, bores in superficial and confined groundwater aquifers, the Perth Seawater Desalination Plant and the Southern Seawater Desalination Plant. Plans to meet future increases in public water supply demand include:

 transferring groundwater abstraction to the deeper aquifers to protect the groundwater environment;

 groundwater replenishment (managed aquifer recharge);

 expanding seawater desalination capacity;

 continuing improvements in water use efficiency; and

 using wastewater recycling as a resource for industry, public open spaces and agriculture.

All groundwater use for both potable and non-potable supply (with the exceptions of stock and domestic use) must be licensed by the Department of Water and licence applications are assessed to ensure the proposed taking and use of water is ecologically sustainable and environmentally acceptable.

It is possible that cumulative impacts of ongoing increases in licensed groundwater abstraction could lead to reduced surface water and groundwater levels at the Ramsar sites. This risk will be managed through the Department of Water allocation planning and licencing processes.

The proposed development is also likely to result in increased abstraction from shallow aquifers through garden bores which are exempt from licensing. These bores can be used for domestic use, non- intensive stock watering and irrigation of lawns and gardens (<0.2 ha). The Department of Water estimates and accounts for garden bore use when setting groundwater allocation limits. To preserve water resources and encourage greater water use efficiency by the community water restrictions on the use of garden bores were initiated in 2007 on the Rights in Water and Irrigation Exemption (Section 26C) Order 2007. In 2010, the total winter sprinkler ban came into effect and is enforced by the Water Agencies (Water Use) By-laws 2010. The by-laws restrict use of domestic garden bores to a roster of three days a week with a total use-ban during winter.

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Strategic Assessment for the Perth and Peel Regions

The annual winter sprinkler ban is now in its sixth year. It has become an accepted part of the water use calendar, as evidenced by a strong reducing trend in infringements for using garden bores during the ban.

The Department of Water also encourages good practice use of garden bores:

 via its Operational policy 5.17 - Metropolitan domestic garden bores, which discourages the use of bores in areas deemed unsuitable; and

 by recommending: o establishment of water efficient gardens that incorporate appropriate plant and surface treatment selection;

o industry best practice irrigation techniques; and o water efficiency measures to ensure the most efficient use of water.

Changes to ecological values of the sites from increases in population

The future development of the Perth and Peel regions is expected to support population growth of 3.5 million people. Currently, the natural and aesthetic values of the Ramsar sites and their close proximity to urban areas attract a range of people including local residents and tourists participating in a wide variety of activities including, bush walking, bird watching, picnicking, environmental study and education, 4WD and trail bike riding, horse riding, fishing, swimming, boating and water sports. An increase in population as a result of urban growth will likely intensify any existing impacts and/or the frequency of those impacts and may expand the footprint of those impacts.

The Department of Planning has projected estimates that draft sub-regional frameworks footprints will provide capacity for population increases across the region. The estimated magnitude of these is provided in Table 19-2 below. It has been assumed that given their natural and aesthetic values the distance travelled by users to attend these Ramsar site would likely encompass the Local Government Areas outlined in Table 19-2.

Table 19-2: Projected population estimates

Local government area Estimated population increase Affected Ramsar site/s

Shire of Murray 150,000 Peel-Yalgorup

Shire of Waroona 15,000 Peel-Yalgorup

City of Canning 34,000 Forrestdale and Thomsons Lakes

City of Gosnells 74,000 Forrestdale and Thomsons Lakes

City of Rockingham 100,000 Peel-Yalgorup, Becher Point

City of Mandurah 60,000 Peel-Yalgorup, Becher Point

Peel-Yalgorup, Becher Point, Forrestdale Shire of Jarrahdale-Serpentine 90,000 and Thomsons Lakes

City of Armadale 87,000 Forrestdale and Thomsons Lakes

City of Cockburn 67,000 Forrestdale and Thomsons Lakes

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Local government area Estimated population increase Affected Ramsar site/s

Becher Point, Forrestdale and Thomsons City of Kwinana 55,000 Lakes

Activities with the potential to impact Ramsar sites resulting from increased population pressure may be undertaken both lawfully and illegally. These include:

 access by vehicles (4WDs, trail bikes), pedestrians, campers, recreational fishers, bird-watchers, horse-riders, dogs and cats;

 boating and kayaking / canoeing;  fishing, crabbing, prawning; and

 arson and campfire fire escapes.

WA State Agencies used data from several sources to support the analysis around increased population pressure. This includes information about what has historically occurred and continues to occur at each of the sites, in terms of usage and people pressures. The data is largely based on observations from on- ground site inspections, monitoring data (where available), aerial photography and information contained in management plans, and from stakeholder discussions.

Potential impacts from access to Ramsar sites

Access to the Ramsar sites from increased number of users presents the largest potential indirect ‘people pressure’ impact to the Ramsar sites. Access, both legal and illegal, occurs from vehicle use (4WD, trail bikes); pedestrians; campers; recreational fishers; bird-watchers; horses and their riders; and dogs and cats. Combined, this potentially results in:

 physical damage to wetlands and associated vegetation, particularly if access is not confined to existing tracks, trails and campsites;

 trampling and destruction of Thrombolites (Peel-Yalgorup System only);

 introduction and spread of weeds and dieback; and  disturbance to and predation on migratory shorebirds, waterbirds and other fauna.

Potential impacts from boating and fishing

The Economic Development and Recreation Management Plan for the Peel Waterways (PIMA 2002) identified erosion of foreshores in the estuary from boat wash as a major threat to fringing vegetation. This has the flow-on potential to not only increase the problem of shoreline erosion but also to negatively impact on fauna relying on fringing vegetation for foraging, roosting and breeding habitat (e.g. waterbirds). Launching non-powered vessels in areas without appropriate infrastructure (i.e. boat ramps) can also have similar effects.

Much of the boating in the Peel-Harvey Estuary is linked to fishing, crabbing and prawning. Apart from the impacts of the boats themselves, there are also the effects of direct take of target species and by- catch and indirect effects to other fauna and ecosystems (e.g. from abandoned gear, benthic habitat disturbance). An increase in night-time lighting of waterways (from boat lights and cars launching boats) may also disturb behaviour of both nocturnally active and sleeping fauna.

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Potential impacts from fire

Fires may be either started deliberately (arson) or via escapes from camp/cooking fires. Once lit, these fires can result in significant damage to wetland vegetation and fauna, while fire fighting activities may also cause physical damage to wetland areas.

19.5.4 Risk assessment of potential indirect impacts from the classes of action

A risk assessment framework was determined to be the most appropriate method for analysing the potential indirect impacts to Ramsar sites. For ground and surface water issues, detailed modelling is not available, nor is the level of detail around the proposed classes of action sufficient to provide meaningful quantitative results. There is also uncertainly around future visitation/usage of each of the Ramsar sites as population increases. Some assumptions can be made based on current usage and associated pressures at each site, however it was considered that attempting to quantify this would not provide robust outcomes.

As a result, risk assessments were carried out by WA Government agencies to examine the potential indirect impacts for each Ramsar site from the proposed classes of action. The methodology for the risk assessments is provided below, while the results are presented in the discussion of each site.

Overall risk rating

For each Ramsar site, the risks associated with changes to the groundwater and/or surface water, and increasing population pressures from the classes of action were determined.

Risks were determined as a function of the likelihood of an event occurring and the consequence of that event (should it occur) as indicated in Table 19-3.

Table 19-3: Risk rating table

Consequence

Likelihood Negligible Minor Moderate Major Extreme

Almost certain Medium High High Very High Very High

Likely Medium Medium High High Very High

Possible Low Medium Medium High High

Unlikely Very Low Low Medium Medium High

Rare Very Low Very Low Low Medium Medium

Likelihood

The five categories of likelihood were defined as:

 Almost certain – is expected to occur.  Likely – strong probability of occurrence in the next 30 years.  Possible – better than even chance of occurrence at some time in the next 30 years.  Unlikely – not expected to occur, except in exceptional circumstances.  Rare – not expected to occur at all.

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Consequence

Consequence was also determined in five categories and was separated for individual components or values of the Ramsar sites as per Table 19-4.

19.5.5 Eutrophication risk

Water quality is recognised as a concern for each of the Ramsar sites. In particular, the Peel-Harvey Estuary system has a long history of water quality decline and related impacts. Where (nutrient related) water quality was given a risk rating of high or very high in the overall risk rating, further assessment was undertaken using data from the Department of Water to identify eutrophication risk associated with each of the proposed new urban, industrial and rural residential areas.

In a similar manner to the broad risk assessment, the eutrophication risk assessment used a likelihood and consequence approach to determine a risk rating for a particular location. Likelihood refers to the likelihood of phosphorus leaching from a given land unit to where it has the potential to contribute to eutrophication of surface water. This was based on phosphorus export hazard maps from Department of Agriculture and Food Western Australia (van Gool et al 2005).

The consequence variable reflects the sensitivity and values of the receiving environment. For example, within the Peel-Harvey coastal catchment, areas draining directly to the estuary or within 1,000 m of it were given the highest consequence rating, based on the sensitivity to nutrient enrichment, ecological and social values. Areas draining to major tributaries had a lower consequence rating, followed by areas further from the main drainage lines. For other Ramsar sites, land within 500 m of the boundary was given the highest consequence rating.

It should be noted that the phosphorus export hazard mapping was developed for use in assessing leaching potential under broadacre agricultural land use. It therefore does not account for the changed hydrological pathways (introduction of drainage) that may occur under urban or industrial land use or the presence of septic tanks or ATUs which may act as nutrient point sources.

Relative risk has been calculated for all new urban, industrial and rural residential areas within the Peel- Harvey coastal catchment and within 5 km of the Forrestdale and Thomsons Lakes Ramsar boundary on a scale of 1-10, with 10 being those areas with highest risk of contributing to nutrient enrichment.

Although eutrophication risk data is proposed to be developed for nitrogen in the future, at the time of writing, data was available for phosphorus only. Phosphorus is of great importance in freshwater ecosystems because it is often the nutrient limiting primary production (Davis et al. 1993). In the Peel- Harvey Estuary phosphorus has also been identified as the limiting nutrient and driver to algal growth. For these reasons this is not seen as a limitation of the assessment.

19.5.6 Defining conservation commitments

Mitigation and management requirements have been formulated to meet the conservation outcomes and objectives of the wetlands and to reduce impacts. They are framed below and in the Strategic Conservation Plan (Action Plans F and G) as conservation commitments for the Ramsar sites.

While the three Ramsar sites have differences in their values, threats and management regimes, they do share many commonalities and therefore similar future management and mitigation actions are often appropriate. Required management and mitigation measures are presented for each site in terms of:

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 Existing arrangements that are currently in place to manage the sites directly and/or their values (e.g. groundwater of the region in which the site exists). These are usually statutory or a part of Reserve management plans.

 Future arrangements, which are required in addition to current arrangements to future address potential impacts to the sites from the classes of action, as identified in this impact assessment.

Management and mitigation measures have been developed in consultation with key WA State Government Agencies, including the Department of Premier and Cabinet, the Department of Water, Parks and Wildlife, and Fisheries.

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Table 19-4: Consequence table for Ramsar risk assessment

Consequence Ramsar site value Negligible Minor Moderate Major Extreme

Ground and surface water quantity (change in depth, extent, volume, flow, recharge, wetting drying frequency, timing or duration) Levels of change (if any) are Levels of change are just Changes are outside natural Changes are substantially Changes are substantially within natural variations, or outside natural variation, variations, frequent or outside natural variations, outside natural variations, Ground and surface are so low as to be short-term, infrequent and periodic, but naturally long term but reversible with long term or permanent and water quality undetectable. reversible. reversible. management. irreversible. (changes in chemical composition, pH/salinity, turbidity/sedimentation or contamination due to pollutants, nutrients)

Littoral vegetation Alteration or disturbance 1 to 5% of the 5 to 10% of the 10 to 30% of the Greater than 30% of the and/or ecological within natural variability. vegetation/communities vegetation/communities vegetation/communities vegetation/communities communities Less than 1% of the affected in a major way or affected in a major way or affected in a major way or affected in a major way or vegetation/communities removed. Reestablishment removed. Reestablishment removed. Reestablishment removed. Reestablishment affected or removed. in less than 1 year. in 1 to 5 years. in 5-10 years. in >10 yrs.

Thrombolites No alteration or disturbance Less than 1% of the 1-5% of the Thrombolites 5-10% of the Thrombolites Greater than 10% of the to the extent or condition of affected in a major way or affected in a major way or affected in a major way or Thrombolites affected in a Thrombolites. removed. removed. removed. major way or removed.

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Consequence Ramsar site value Negligible Minor Moderate Major Extreme

Migratory shorebirds No alteration to the amount, Minor alteration (1-5%) to Moderate alteration (5-10%) Major alteration (10-30%) to Extreme alteration (>50%) and other wetland condition* or type of suitable the amount, condition* or to the amount, condition* or the amount, condition or to the amount, condition or birds habitat for shorebirds. type of suitable habitat for type of suitable habitat for type of suitable habitat for type of suitable habitat for Shorebird species diversity shorebirds. Shorebird shorebirds. Shorebird shorebirds. Shorebird shorebirds. Shorebird and abundance within species diversity and species diversity and species diversity and species diversity and recent historical levels. abundance is maintained abundance is negatively abundance is negatively abundance is negatively * condition of suitable with recent historical levels. impacted from recent impacted from recent impacted from recent habitat includes no * condition of suitable historical levels with no historical levels with an historical levels with local disturbance from habitat includes disturbance effect on population viability effect on population viability extinctions imminent/ pedestrians/dogs/cats. from pedestrians/dogs/cats and/or dynamics. and/or dynamics. immediate or population no in a few places, rarely. * condition of suitable * condition of suitable longer viable. habitat includes disturbance habitat includes disturbance * condition of suitable from pedestrians/dogs/cats from pedestrians/dogs/cats habitat includes disturbance in some places, some of the in many places, most of the from pedestrians/dogs/cats time. time. in most places, all of the time.

Ecosystem function Localised, temporary Localised measurable Measurable changes to few Measurable changes to few Measurable changes to disturbance to ecosystem changes to few ecosystem ecosystem components at ecosystem components most ecosystem within natural variability. components without a major numerous sites or to several across the entire Ramsar components at many change in function or loss of ecosystem components at a site or to most ecosystem locations. Major change in components. Recovery in localised site. No major components at some sites. ecosystem function, with a less than 1 year. change in function or loss of Major change in ecosystem long term or irreversible loss components. function, with a partial loss of some components. Recovery in 1 to 2 years. of some components. Recovery, if at all, greater Recovery in 3 to 10 years. than 10 years.

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Strategic Assessment for the Perth and Peel Regions

19.6 MONITORING

Monitoring across the three Ramsar sites is important to meet a range of needs (see Table 19-5). Conservation commitments around monitoring are made in relation to each of the sites and the specific measures are incorporated into the Assurance Plan (Action Plan I).

Table 19-5: Need for Ramsar monitoring

Monitoring Details requirements

The Western Australian government will need to be able demonstrate that the conservation outcomes and objectives committed to through this strategic assessment are being met. Reporting For Ramsar sites, this will require monitoring to determine if the key elements of ecological requirements for character have an ‘ongoing presence’ at each of the sites. this assessment There will be periodic review of conservation commitments (e.g. management actions) and there needs to be information available as to whether these commitments were both implemented and effective. This is a key step in the adaptive management pathway.

In order to manage the Ramsar sites well (and therefore fulfil Australia’s international obligations), there is a need to monitor the effectiveness of implemented actions to determine if they are working effectively (e.g. are water allocation limits allowing sufficient Effective Ramsar water to remain in the system for environmental purposes?). site management For some sites (e.g. Forrestdale Lake) additional information is required to determine the best management strategies (and therefore investment). This requires additional investigation and baseline monitoring.

As a signatory to the Ramsar convention, Australia must be able to report on the ecological Ramsar reporting character of its Ramsar sites. This requires monitoring of key parameters (i.e. those requirements indicated in the LACs).

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Strategic Assessment for the Perth and Peel Regions

19.7 BECHER POINT WETLANDS

19.7.1 Description of the wetland

The Becher Point Wetlands Ramsar site (Figure 19-2) was listed as a Wetland of International Importance under the Ramsar Convention in January 2001.

The Ramsar site is part of the Port Kennedy Scientific Park (Nature Reserve 44077) and exists approximately 9 km south of the city of Rockingham. Excluding a small section in the southwest, the reserve is vested in the Conservation Commission for the purpose of ‘Conservation of Flora and Fauna’ and is administered by the Department of Parks and Wildlife as part of the Rockingham Lakes Regional Park.

The Ramsar site covers approximately 677 ha and is made up of approximately 60 small wetlands (Ramsar Information Sheet). These are made up of chains of small linear, ovoid or irregular shaped basins arranged in five groups, each roughly parallel to the coast and separated by sand ridges. The wetland series ranges in age from 1000 – 5000 years and exhibits a continuum of development in geomorphology, sedimentary fill, hydrology, hydrochemistry and vegetation.

The sedgelands that occur within the linear wetland depressions of the Ramsar site are listed as a threatened ecological community (TEC) under the EPBC Act (Sedgelands in Holocene dune swales of the southern Swan Coastal Plain) and is listed as endangered (see Chapter 18). The system is considered to be a unique wetland system in Western Australia.

Key features of the Becher Point wetlands are summarised below and a detailed description is provided in Appendix D.

 The wetlands are comprised of an extensive geological sequence of linear interdunal swales with calcareous/quartzose sediments.

 There are approximately 60 wetlands encompassed within the Ramsar site, and this is part of a larger suite of up to 300 wetlands.

 The wetlands are freshwater and entirely groundwater fed, with seasonal recharge during high rainfall periods.

 The distributions of plant communities within and amongst the wetlands are diverse and extremely dynamic, with very different flora assemblages developing between wetlands in close physical proximity.

 The Becher Point wetlands contain 20.3 ha of the Sedgelands in Holocene Dune Swales of the Southern Swan Coastal Plain TEC, which represents approximately 12.4% of the TEC’s entire distribution (164 ha).

 Some shorebird species have been recorded using the beach areas of the site in numbers >0.1% of their flyway population. More commonly, the site provides transient foraging habitat.

 A history of traditional owner use of the Becher Point Wetlands Ramsar site has not been determined but it’s scientific and education values are high due to its uniqueness.

 Management of the site is guided by the Rockingham Lakes Regional Park Management Plan 2010 (Department of Environment and Conservation on behalf of the Conservation Commission of Western Australia 2010) and the 2011-2016 Interim Recovery Plan (DEC 2011a) for the EPBC Act listed Threatened Ecological Community Sedgelands in Holocene Dune Swales.

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 Water allocation limits have been set of the Rockingham Groundwater Area and their development considered the environmental requirements of wetlands, include those at Becher Point. The current groundwater licence entitlements surrounding Becher Point Ramsar site are within the allocation limits.

 Current threats to the Ramsar site include urban development, changes to hydrological regimes, fire, problem introduced species and recreation.

19.7.2 Ramsar listing criteria

The Becher Point Wetlands Ramsar site meets two of the nine Ramsar listing criteria. The listing criteria and justification are presented in Table 19-6 below and have been taken from the Ramsar Information Sheet (RIS) for the site.

Table 19-6: Ramsar listing criteria and justification for Becher Point Wetlands

Criterion Justification

1: A wetland should be The Becher Point Wetlands Ramsar site comprises an example of shrub swamps considered internationally and seasonal marshes formed in an extensive sequence of interdunal depressions important if it contains a that have arisen from seaward advancement of the coastline over recent millennia. representative, rare, or This geomorphological sequence of Holocene wetlands is rare in the South-West unique example of a Coast bioregion and is one of the youngest wetland systems on the Swan Coastal natural or near-natural Plain. Examples of this type of geomorphological sequence in equally good wetland type found within condition and within a protected area are considered rare globally (Semeniuk 2007). the appropriate In addition to the presence of a nationally endangered sedgeland community, the biogeographic region. conservation values of the wetlands are primarily related to the geomorphic significance of the site and the respective location of the wetlands along the evolutionary time sequence. When conserved as a representative unit, the relative youth of the wetlands, and the range of wetlands of different ages in association with their geomorphic history, provide important opportunities for research on wetland evolution (V & C Semeniuk Research Group 1991).

2: A wetland should be The Becher Point Wetlands Ramsar site supports a nationally listed threatened considered internationally ecological community ‘Sedgelands in Holocene dune swales of the southern Swan important if it supports Coastal Plain’. The sedgeland community is nationally listed as Endangered under vulnerable, endangered, or the EPBC Act. critically endangered The sedgeland community has a restricted distribution and is almost entirely located species or threatened within linear wetland depressions (swales) occurring between parallel sand ridges of ecological communities. the Rockingham-Becher Plain in south-west Western Australia. The best record of the sedgeland community occurs along a linear transect from the Ramsar site through to the hinterland, which spans the last 8,000 years of the Holocene Epoch (DEC 2011a). The sedgeland community within the Ramsar site is particularly important for the outstanding demonstration of a continuous depositional history of sediment during the last 3,000 years.

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Figure 19-2: Location of Becher Point

Legend

Strategic Assessment Area 0 0.55 1.1 Kilometres Ramsar Wetland Sub- Datum/Projection: group: GDA 1994 MGA Zone 50 Data Source: DPaW Becher Point Wetlands Prepared by: JL Date: 19/11/2015 ± Strategic Assessment for the Perth and Peel Regions

19.7.3 Current condition

Overall, the condition of the Becher Point wetlands is good and this condition is being maintained over time. Key components and processes within the wetland, which have moderate condition and appear to be on a declining trend include:

 water levels within the wetlands in the northern and eastern areas of the Ramsar site;

 total phosphorus and total nitrogen levels in groundwater have been elevated in relation to LAC levels at some monitoring time points in the last few years; and

 fire events have been more frequent than the LAC stated frequency.

The current condition of the Becher Point wetlands is discussed in detail Appendix D. Table 19-7 summarises the results of the condition assessment with reference to the LACs.

19.7.4 Conservation objective

The conservation objective for the Becher Point Ramsar site is:

Maintain the ecological character of the Becher Point Ramsar site via the ongoing presence of the following characteristics:

o A suite of approximately 60 discrete, small wetlands in inter-dunal swales.

o Geological sequence of wetland ages with corresponding evolution of wetland characteristics.

o Seasonal wetting of inter-dunal swales.

o Water quality that is not saline, acidic or eutrophic.

o Vegetation dominated by native plants and very low abundance of Typha. o No loss of Sedgelands in Holocene dune swales of the southern Swan Coastal Plain TEC.

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Table 19-7: Summary of the condition against each of the LACs for Becher Point Wetlands

Components and Limits of acceptable change (LAC) Condition Trend processes

Geomorphology Extensive geological sequence of linear interdunal swales with calcareous/quartzose sediments. No LACs have Good Stable been established but a provisional LAC is that there should be no loss of interdunal swale occurrences.

Water levels Seasonal rainfall, rise in groundwater and reduced evaporation facilitate seasonal wetting of dunal swales. The Moderate (northern Degrading limits of acceptable change are expressed as water level ranges and levels above ground level. They are and eastern areas) (northern and different for each wetland (see Appendix D); though, the maximum range is 126cm, with minimum to maximum Good (elsewhere) eastern areas) values exist between 59cm and -168cm. Stable (elsewhere)

Period of Period each year where water level reaches long term mean maximum (1991-2008 ECD). LAC not yet NA NA inundation developed.

Hydrochemistry Salinity: Measured as Total Dissolved Solids - combined content of all inorganic and organic substances Good Stable contained in the surface water. The limits of acceptable change are significantly different for each wetland (see Appendix D).

pH (groundwater): Disturbance of Acid Sulfate Soils in the catchment could be expected to lead to oxidation of Good Stable sulfur containing sediments and showing as lowered pH. The limits of acceptable change are different for each wetland (see Appendix D); though, exist between pH 6.9 and 8.1.

Total phosphorous in groundwater: The limits of acceptable change are significantly different for each wetland Moderate Interim degrading (see Appendix D).

Total nitrogen in groundwater: the LAC is set at the ANZECC value of max 1,500 ug/L. Moderate Interim degrading

TECs Nationally listed threatened ecological community ‘Sedgelands in Holocene dune swales of the southern Swan Good Interim stable Coastal Plain’. No LAC has been established but the interim limit is no loss of TEC occurrences.

Native Species Abundance cover > 25%. Good Stable Cover

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Components and Limits of acceptable change (LAC) Condition Trend processes

Fire (surrogate Fire events within individual reserve portions occur less than once per every 6 years. Moderate Degrading indicator)

Weed cover Good Stable to improving Any presence of a declared weed. (surrogate indicator)

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19.7.5 Analysis of relevant impacts

The following section discusses potential impacts to the Becher Point Ramsar site. As discussed above, the Ramsar site does not fall within the footprint of a proposed class of action, and therefore no direct impacts are anticipated.

However, there are a range of potential indirect impacts that are relevant including those relating to changes to the groundwater regime (the wetlands are entirely groundwater fed) and others associated with increased ‘people pressure’ to the site.

Impacts are assessed in accordance with the methodology described in Section 19.4 above.

Changes to ground water and/or surface water

Introduction

The potential impacts to groundwater and/or surface water are examined within the scope of proposed development including:

 infrastructure; and

 planned future urban, industrial and rural residential land within a 5 km radius of Becher Point Wetlands.

The total areas of existing and proposed urban, industrial and rural residential development within the relevant areas that inform the assessment are given in Table 19-8.

Table 19-8: Existing and proposed development around Becher Point Ramsar site

Area within 5 km (ha) Urban Industrial Rural residential

Existing 2,611 135 431

Expansion 700 - 612

Future total 3,311 135 1,403

Becher Point wetlands are entirely groundwater dependent and therefore this assessment considered only the hydrogeological properties of the Superficial and Rockingham aquifers. Any development outside this area is unlikely to have any impact in relation to potential changes to surface or groundwater at the site.

The Becher Point Ramsar site is part of the conservation estate, and is currently bordered by the Indian Ocean to the west, medium density urban development and golf courses to the north and south and regional playing fields with rural and rural residential land to the east.

The site is located within the Churcher West subarea of the Rockingham Groundwater Area. The Rockingham-Stakehill Groundwater Management Plan, released in 2008, sets allocation limits for the area. The Department of Water revised allocation limits for the plan in 2007 based on PRAMS (Perth Regional Aquifer Modelling System) modelling and considered water requirements for recognised

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wetlands within the area including the Becher Point wetlands (DoW, 2008a). With the exception of Cooloongup and Karnup West Subarea, there is water available for licensing.

Current pressures

Groundwater levels across the Perth and Peel region are under pressure from a drying climate. Within the Becher Point Ramsar site, water levels within individual wetlands are generally stable and remain within the limits of acceptable change, although there is evidence of the drying trend. The exception to this is for wetlands in the north and east of the site, where there have been significant declines in water levels monitored at three bores. This decline has been attributed to the cumulative effect of drying climate and groundwater abstraction from the licenced bores at Kennedy Bay Golf Course.

Water quality trends within the wetland are mixed. The wetlands continue to retain their freshwater character and neutral pH. However, there is early evidence from monitoring that nitrogen and phosphorous levels are increasing within the groundwater system. The most likely cause of this is nutrients leaching into the system from fertiliser application to the nearby golf course and urban areas. However, further investigation is required before firm conclusions can be drawn about the extent and severity of nutrient contamination in the groundwater and any flow-on effects on wetland function.

Future pressures and risks (broad scale)

The risk assessment work undertaken by the Department of Water has identified future pressures to groundwater resources at Becher Point Ramsar site and their relative risk levels. These are summarised in Table 19-9 and then further discussed below.

Table 19-9: Summary of groundwater risk assessment for Becher Point Ramsar site

Potential impact Risk to quantity Risk to quality

Impacts from construction – temporary dewatering Low Medium

Impacts from construction – activation of ASS NA Medium

Impacts from construction – contamination NA Low

NA – potentially Removal of vegetation and increased developed footprint Medium beneficial

Alterations to drainage Low Low

Groundwater abstraction – non-potable supply (irrigation and High High licence - exempt uses)

Groundwater abstraction – potable supply (public water Medium Low supply)

NA – potentially Groundwater management activities High beneficial OR medium

Overall, groundwater abstraction from the Superficial aquifer for non-potable supply present a future high risk to groundwater quality and quantity, whilst groundwater management activities (e.g. managed aquifer recharge schemes) present a high risk to groundwater quality.

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Impacts from construction present a low to medium future risk to the Becher Point Ramsar site. This is due to:

 Groundwater drawdown from construction dewatering is likely to have a limited extent, be temporary, be located away from the Ramsar site and is well regulated.

 The majority of the study area is mapped as no known risk of acid sulfate soil disturbance with the exception of isolated wetlands within the Ramsar site and other Conservation Category Wetlands within the wider area including Lakes Cooloongup and Walyungup. Significant buffering capacity exists within the Safety Bay Sand and Tamala Limestone.

 Contamination events are likely to be few and have regulatory clean-up controls in place. The depth to groundwater across the study area and groundwater flow direction means that the likelihood of contaminants penetrating the groundwater is low.

Increased recharge to the superficial aquifer resulting from vegetation clearance and large impervious surfaces has potential positive and negative impacts to the Ramsar site. Increasing the static water levels in the superficial aquifer can potentially raise water levels at the Ramsar sites and may also prevent seawater intrusion. Negative impacts include contaminated water recharge, which is partially mitigated by first-flush systems and water sensitive urban design, and is therefore considered medium risk.

No surface drainage exists within the vicinity of the Becher Point Ramsar site due to free draining sediments and depth to groundwater. Sub-surface drainage should not be required for any proposed development within the broader area due to the clearance between the ground surface and the maximum groundwater levels.

The specific draw point locations and volumes of any ongoing abstraction associated with the development are not able to be quantified at this stage. However, there are identified future uses resulting from the classes of action that have the potential to reduce groundwater levels within the Ramsar site, including irrigating public open space, golf courses and sporting complexes and usages which are exempt from licencing in rural residential development. The cumulative impacts of some of these uses (i.e. golf course irrigation) along with drying climate are already being observed in parts of the Ramsar site. Whilst the current changes have not resulted in noticeable changes to wetland ecosystems, there is the potential for the situation to exacerbate over time, and in particular with increasing development and associated pressure on water resources.

There is limited water available across the Rockingham-Stakehill groundwater area. Three superficial resources are fully allocated therefore new licence entitlements will not be allocated to these resources. Therefore, adaptive management is fundamental to the groundwater allocation planning process, as such the Department of Water have evaluated the Rockingham-Stakehill Groundwater Allocation Plan since its release in 2008. Recent evaluations indicate that the allocation limits may need to be reviewed in line with the drying climate. The review will be undertaken in 2016-17.

There is currently no groundwater licensed for public water supply from the subareas. There is also no public water supply or public water supply reserve component set under the allocation limits, which means it is also unlikely that there will be groundwater licensed for potable supply from the subareas in the future. Future increases in demand for potable water in urban and industrial development will be provided by the IWSS and are likely to be met using sources other than groundwater such as seawater desalination and groundwater replenishment. Groundwater abstraction for the IWSS is a significant distance from the Becher Point Ramsar site. 19-31

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Managed aquifer recharge is being considered in a number of locations on the Swan Coastal Plain, particularly where there are existing or proposed wastewater treatment plants. There is one wastewater treatment plant under construction to the north of Becher Point (Water Corporation East Rockingham Wastewater Treatment Plant) and land set aside for a second treatment plant to the east of the wetlands. The City of Mandurah is currently looking at the potential for managed aquifer recharge and irrigation of public open space from the Water Corporation’s Caddadup Wastewater treatment plant. This is being managed through Department of Water and any managed aquifer recharge program would investigate any impacts on wetlands. Other opportunities for managed aquifer recharge to occur utilising treated wastewater are also possible, however specific details with regards to a potential project are currently unknown.

It is likely that a managed aquifer recharge project will cause increases in groundwater levels in the wetlands which could provide a potential benefit by offsetting a reduction in groundwater levels as a result of other activities. However without appropriate controls in the recovery of recharged water, a reduction in water levels may also occur. The introduction of additional water into the aquifer upstream of the wetlands could increase the volume and movement of nutrient enriched groundwater entering the wetlands. Careful consideration and planning of any managed aquifer recharge, including an assessment of all potential risks will be required.

Increasing people pressures

Current pressures

The coastal nature and aesthetic values associated with the Becher Point Ramsar site attract a range of people including local residents and tourists. Fishing, swimming and boating are popular activities in the coastal areas (DEC 2010a). The usershed of the site is likely to be significantly greater than that of a local urban park, due to the popularity of coastal activities and the close proximity of the Port Kennedy boat ramp.

This site is located in close proximity to urbanisation, and recreational activities affect several areas that contain the EPBC Act listed Sedgelands in Holocene Dune Swales TEC. Pedestrian access by means of formal and informal walk trails can have a negative effect on the TEC as people walk through occurrences and trample vegetation. Unauthorised vehicle access is a major problem in several groups of TEC occurrences in particular Port Kennedy Scientific Park, IP14 and east of Bakewell Drive (Interim Recovery Plan, DEC 2011a).

Fences bordering these TEC sites are regularly breached enabling four wheel drives and trail bikes to access these areas. As a result issues such as rubbish dumping, increased fire frequency, trampling of vegetation and increased weed spread are noticeable (Interim Recovery Plan, DEC 2011a). Unauthorised vehicle access is also an issue on adjacent beaches where it has caused erosion and damage to vegetation (DEC 2010a).

Future pressures and risks

The risk assessment work undertaken by Parks and Wildlife has identified future ‘people pressures’ to ecological values at Becher Point Ramsar site and their relative risk levels. These are summarised in Table 19-10 and then further discussed below. Overall, unlawful vehicle access presents a future high risk to both the structure of the wetlands dunes and swales and the TEC vegetation as well as to

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migratory shorebirds. Fire (both arson and campfire escapes) also presents a future high risk to the TEC.

Table 19-10: Summary of people pressure risk assessment for Becher Point Ramsar site

Risk to wetland Risk to Potential impact Risk to sedgeland TEC structure shorebirds

High – physical disturbance; Access (unlawful) – vehicles High High weeds & dieback

Access (unlawful) – pedestrians, Medium – physical NA Medium recreational fishers disturbance; weeds & dieback

High – physical disturbance, Fire – arson and campfire escapes NA NA death

Illegal vehicle access is likely to have considerable future impacts to the ecological character of the Becher Point Ramsar site, unless appropriate measures can be put in place to prevent access to the site. Four wheel drives and trail bikes have the potential to cause considerable damage to the dune and swales structure of the wetland, particularly with repeated access to the same areas. Whilst this damage also physically disturbs vegetation, the presence of vehicles within the wetland can lead to the introduction and spread of weeds and dieback. Currently, the site is in good condition with respect to weeds, with the limit of acceptable change for weeds on a stable to improving trend. Any future risk to this from increased vehicular access would be of concern.

Pedestrian access (including recreational fishers accessing the beach) has a lesser potential to impact the site but may result in some disturbance to the sedgeland TEC if formed paths are not utilised as well as the introduction and spread of weeds and/or dieback. Solutions to manage the more significant issue of illegal vehicle access/use are also likely to adequately address pedestrian access issues.

Both vehicles and people have the potential to disturb shorebirds. A number of shorebirds (EPBC Act listed migratory shorebirds and other species e.g. Pelicans) have been recorded within the beach sections of the Becher Point Ramsar site. Their usage of this area is likely to be casual roosting (see Appendix D), but roosting birds will be susceptible to disturbance from vehicles in particular, as fishers and recreational 4WD’ers access the beach. This disturbance risk increases with increasing vehicle traffic.

Fire presents a significant risk to the site, whether it is started by arson or escape of cooking campfires from recreational fishers. The predicted frequency of both types of fire event is expected to increase with greater usage of the site and surrounding urban populations. Fire has the potential to significantly impact on the wetland vegetation if not appropriately contained. The ability for agencies to contain fires within the wetland can be constrained in certain circumstances due to risks associated with unexploded ordinance.

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19.7.6 Mitigation and management

Changes to groundwater

The most significant future risks to the groundwater regime of the Becher Point Ramsar site are increased groundwater abstraction for non-potable supply (e.g. for irrigation of new areas of public open space) and groundwater management activities (e.g. managed aquifer recharge schemes). Both these risks can be successfully managed and mitigated via the appropriate application of the planning process. This process is led by the Department of Water and involves a range of measures as discussed below.

The Department of Water will continue to manage groundwater abstraction in the region in accordance with the requirements of the Rights in Water and Irrigation Act 1914. Groundwater allocation limits (that include estimates of exempt use) for the Rockingham Groundwater Area and licensing in the vicinity of the Becher Point Wetlands are guided by the Rockingham-Stakehill groundwater management plan (DoW 2008a). For a licence to be granted, there must be water available under the allocation limit in the subarea in which the proposed development is located. With the exception of Cooloongup and Karnup West subarea there is water available for general licensing in vicinity of Becher Point. Any licensing requirements associated with the proposed development in subareas where water is not available would rely on licence transfers through the development process or on licence trades.

There is also currently some water available for public water supply from the Jandakot groundwater area. Volumes currently licensed within the proposed development area could be transferred for use as water for public open space so that abstraction does not increase as the areas are developed. As the areas are developed, opportunities to reduce licensed groundwater use through licence transfers and maximum efficiency of water for public open space should be explored.

The installation of new garden bores should be limited near the wetlands and be guided by Operational policy 5.17 – Metropolitan domestic garden bores (DoW 2011) which emphasises water conservation and efficiency and by the garden bore suitability map. Any future opportunity to strengthen this advice into a more formally regulated process is likely to be advantageous.

The Department of Water will continue to:

 manage groundwater abstraction within allocation limits and regularly review allocation limits through an adaptive management process;

 monitor water regional groundwater level;  assess annual monitoring provided as a condition of groundwater licences in the vicinity of the Becher Point Wetlands Ramsar site;

 undertake compliance inspections and meter audits to ensure groundwater use is within licence entitlements;

 work with local government and other licencees to improve water use efficiency including design and maintenance of public open space;

 determine appropriate areas for and implement water restrictions on the use of garden bores;

 work with the Department of Parks and Wildlife in the implementation of the Interim Recovery Plan for the Sedgelands in Holocene Dune Swales TEC;

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 develop strategies and management plans to protect the quantity and quality of water resources, protect infrastructure from flooding, and enhance the living environment for the community through the development of allocation plans and water quality improvement plans; and

 provide advice with regard to water quantity and quality to the Western Australian Planning Commission and the Local Government Authority under Better Urban Water Management to inform decision making through the State planning process.

Finally, the Better Urban Water Management Framework will remain the primary mechanism for protection of water quantity and quality through the land planning process. The Western Australian Planning Commission will continue to administer and provide for best practice water management across new urban, industrial and rural residential developments in accordance with the Framework. The Department of Water will continue to provide advice to inform decision making through the State planning process.

Increasing people pressures

The required management approach to successfully addressing potential impacts from increasing people pressures is two pronged. Measures are required to:

 prevent and discourage unlawful access to the site and illegal activities (i.e. arson); and

 facilitate managed recreation opportunities so that people can enjoy the values of the site through passive recreation that has been designed in such a way as to avoid and minimise impacts.

Management actions at the Becher Point Ramsar site are currently guided by the Rockingham Lakes Regional Park Plan and it is intended that future management of the area will continue to be embedded in formal park management plans (the coverage and configuration of these may change over time). Key requirements of the future management regime are:

 upgrade and extend the existing vermin proof fence, including adding additional strength fencing to combat unlawful entry/damage, including ongoing maintenance;

 undertake rehabilitation of coastal vegetation complexes including weed control and implementation of feral animal control programs; and

 construct ~9 km of walking paths and boardwalks along existing tracks to facilitate passive recreation and reduce the need for unlawful vehicle access to experience the Ramsar Wetland site. Proposed infrastructure includes a coastal lookout and interpretive signage.

It is expected that the combination of preventative measures (i.e. fencing) and facilitated recreation and rehabilitation will greatly benefit the site and will reduce the risk of inappropriate visitation and usage into the future.

Conservation commitments

The following conservation commitments for the Becher Point Ramsar site are provided in the Strategic Conservation Plan (Action Plan F). They have been developed to address the key risks identified in this assessment and support the broader management regime that exists for the site.

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The conservation commitments are:

 Implement key actions necessary to improve and maintain the health of the wetlands using a whole of catchment management approach, including improvements to the monitoring and reporting on the health of the system.

 Implement a monitoring program that includes the limits of acceptable change, and installing additional monitoring bores to determine impacts from nearby water users to ensure ongoing viability of the vegetation communities of Becher Point wetlands.

 Conserve the ecological characteristics of the Becher Point Ramsar site by managing adjacent land uses and indirect impacts through implementing measures to prevent and discourage unlawful access to the site and illegal activities; facilitate managed recreation opportunities and protect and conserve threatened ecological communities.

 Continue to manage groundwater resources in accordance with the requirements of existing legislation and policy including taking an adaptive management approach to groundwater allocations based on annual evaluations.

19.7.7 Outcome for the Becher Point Ramsar site

This assessment has identified the following key issues relevant to the outcome for the Becher Point Ramsar site:

 There will be no direct impacts to the site from the classes of action, however indirect impacts to water resources and ecological values from increased people pressures are possible.

 Groundwater abstraction from the Superficial aquifer for non-potable supply presents a future high risk to groundwater quality and quantity, whilst groundwater management activities (e.g. managed aquifer recharge schemes) present a high risk to groundwater quality.

 Unlawful vehicle access presents a future high risk to both the structure of the wetlands dunes and swales and the TEC vegetation as well as to migratory shorebirds. Fire (both arson and campfire escapes) also presents a future high risk to the TEC.

 The risks to groundwater values of the site can be effectively managed under existing management and regulatory regimes. This will rely on the Department of Water continuing to manage groundwater abstraction and licencing and pursuing opportunities to strengthen controls on garden bores. A conservation commitment is provided around this issue.

 Management of the ecological values of the site relies on measures to prevent and control access and fire and to better facilitate recreational activities. This is best achieved under the strategic direction of Rockingham Lakes Regional Park Management Plan and Sedgelands in Holocene Dune Swales Recovery Plan. A conservation commitment is provided around this issue.

Based on the current understanding of future risks and the existing and future ability to manage these, the overall outcome for the Becher Point Ramsar site is considered acceptable and is one that meets the conservation objectives. It is anticipated that the ecological character of the Becher Point Ramsar site will be maintained in parallel with the implementation of the classes of action.

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19.8 FORRESTDALE AND THOMSONS LAKES

19.8.1 Description of the wetlands

The Forrestdale and Thomsons Lakes Ramsar site was originally nominated as a Wetland of International Importance in 1990. While the two lakes occur in separate locations, they are listed as one Ramsar site.

Forrestdale Lake is located approximately 25 km south east of Perth, in the City of Armadale and Thomsons Lake is located approximately 34 km south west of Perth in the City of Cockburn (Figure 19-3). Both lakes lie within the southern Perth metropolitan area. The lakes are approximately 8.5 km apart, separated by medium density urban development, rural and semi-rural (rural residential) land. Forrestdale and Thomsons Lakes are Class A nature reserves vested in the Conservation Commission of Western Australia. Thomsons Lake Nature Reserve also forms part of the Beeliar Regional Park.

The two lakes are fresh/brackish, seasonal wetlands, predominately fed by groundwater with little surface drainage. These lakes are the best remaining examples of brackish, seasonal lakes with extensive fringing sedgeland, typical of the Swan Coastal Plain.

Key features of the Ramsar site are summarised below. A detailed description is provided in Appendix D.

 Forrestdale and Thomsons Lakes are situated in sand dune systems and, when inundated, contain large areas of open water that are dominated by submerged and floating macrophytes and fringed by rushes and bulrushes, behind which are trees tolerant of seasonal waterlogging. The higher ground around the lakes supports open woodland.

 The lakes are weakly coloured, generally clear and both have a neutral to slightly alkaline pH.

 The lakes have moderately elevated nutrient concentrations above natural levels and occasional algal blooms have been recorded.

 Forrestdale Lake usually dries out by mid-summer whereas Thomsons Lake retains water for longer periods.

 The Ramsar site contains rich and diverse communities of aquatic invertebrates that are representative of relatively undisturbed, large, shallow Swan Coastal Plain wetlands dominated by submerged macrophytes.

 There are 339 recorded taxa within 1.5 km of the centre of Forrestdale Lake. This includes: two Western Australian listed Threatened Ecological Communities; (SCP08 – Herb rich shrublands in claypans and SCP10a – Shrublands on dry clay flats); seven threatened species; and four priority species.

 There are 302 recorded taxa within 2 km of the centre of Thomsons Lake. This includes: the Western Australian listed Threatened Ecological Community (SCP24 Northern Spearwood shrublands and woodlands); four threatened species; and nine priority species.

 Forrestdale and Thomsons Lakes provide important habitat for waterbirds on the Swan Coastal Plain. 85 species of waterbird occur at the two lakes, including 29 migratory species listed under EPBC Act. In addition, 27 waterbird species have been recorded breeding at the lakes.

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 Forrestdale Lake was traditionally an important turtle hunting site for indigenous peoples from as far away as Pinjarra, 50 km to the south. Contemporary uses of the Ramsar site include bird- watching, nature walks, horse riding and general recreation.

19.8.2 Ramsar listing criteria

The listing criteria, taken from the Ramsar Information Sheet (RIS) for the site are presented in Table 19-11. Ramsar criteria 5 and 6 were once considered met; however upon review these are now not considered to be met for reasons described in Appendix D.

Table 19-11: Ramsar listing criteria and justification for Forrestdale and Thomsons Lakes

Criterion Justification

1: A wetland should be considered Forrestdale and Thomsons Lakes are the best remaining examples of internationally important if it brackish, seasonal lakes with extensive fringing sedgeland typical of the contains a representative, rare, or Swan Coastal Plain. While these types of wetland were formerly common, unique example of a natural or extensive development of the Swan Coastal Plain has resulted in the loss near-natural wetland type found of many of these wetlands, and most of the remaining wetlands of this within the appropriate type have been degraded through drainage, eutrophication and the loss of biogeographic region. fringing vegetation.

3: A wetland should be considered Forrestdale and Thomsons Lakes provide important habitat for waterbirds internationally important if it on the Swan Coastal Plain with 85 species of waterbird occurring at the supports populations of plant and/or two lakes, including 29 migratory species listed under the EPBC Act. In animal species important for addition, 27 waterbird species have been recorded breeding at the lakes. maintaining the biological diversity The Ramsar site contains rich and diverse communities of aquatic of a particular biogeographic invertebrates that are representative of relatively undisturbed, large, region. shallow Swan Coastal Plain wetlands dominated by submerged macrophytes. There are two WA listed Threatened Ecological Communities at Forrestdale Lake Nature Reserve, two ‘Declared Rare Flora’ species listed under WA legislation and nine Priority taxa. Thomsons Lake Nature Reserve contains one ‘Declared Rare Flora’ species listed under WA legislation and three Priority taxa. Thomsons Lake is one of the last remaining refuges within the Swan Coastal Plain for the threatened Australasian Bittern Botaurus poiciloptilus, is one of few known breeding localities for Baillon’s Crake Porzana pusilla, and was the last remaining wetland within the Perth metropolitan area where the Swamp Harrier Circus approximans was known to breed; however, these species have not been recorded breeding at this lake since the mid-1980s.

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Figure 19-3: Forrestdale and Thomsons Lake Ramsar Site

Central

South Metro Peel

Legend

Strategic Assessment Area 0 1.5 3 Kilometres Ramsar Wetland Sub- Datum/Projection: group: GDA 1994 MGA Zone 50 !H Data Source: DPaW Forrestdale & Thomsons Lakes Prepared by: JL Date: 19/11/2015 ± Strategic Assessment for the Perth and Peel Regions

19.8.3 Current condition Since Forrestdale and Thomsons Lakes were first listed under the Ramsar Convention in 1990, many of the components, processes, benefits and services critical to the ecological character of the site have been maintained including:

 Water quality has generally been maintained. The lakes are still fresh/brackish, weakly coloured, generally clear, have a neutral to slightly alkaline pH and are moderately enriched.

 Invertebrate species richness has remained relatively stable. This indicates that conditions remain that support the faunal species, including waterbirds and turtles.

However, there have also been a number of changes to the wetlands. Major changes include:

 The lakes are experiencing substantially lower maximum water depths, reduced period of inundation and earlier annual drying. The altered hydrological regime has been attributed to reduced rainfall from climate change, groundwater abstraction and urban development.

 Wetland vegetation has generally declined in condition since monitoring commenced though in recent years there have been improvements in canopy condition at both lakes.

 Typha orientalis now covers expansive areas of the water’s edge and is encroaching across the lake beds. Typha is displacing and changing riparian vegetation, which appears to be altering waterbird habitat. The invasion of Typha is facilitated by drier conditions and some active control measures have been implemented. These measures have been successful in reducing coverage of Typha around parts of the lakes.

 The number of waterbirds and number of species recorded at Forrestdale and Thomsons Lakes have been variable, but overall have declined in recent years. Numbers of migratory shorebirds have also declined, likely due to loss of suitable habitat from the encroachment of riparian vegetation across the lake floor.

The current condition of Forrestdale and Thomsons Lakes is discussed in detail Appendix D. Table 19-12 summarises the results of the condition assessment with reference to the LACs.

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Table 19-12: Summary of the condition against each of the LACs for Forrestdale and Thomson Lakes Wetlands

Components and Limits of acceptable change (LAC) Condition Score Trend processes

At the sediment surface (wet years), or up to 0.5 m below the lake bed levels (medium years), or 0.5–1.0 m below the lake bed surface (dry years) (DoE 2004) for 3–4 consecutive months annually. Annual minimum Stable to Always < 1.0 m below the sediment surface (DoE 2004). Good to excellent water depth degrading Not 0.5–1.0 m below the sediment surface for longer than 4 consecutive months more than once every ten years or for 2 consecutive years (Froend et al. 1993).

> 0.9 m (DoE 2004) for 2 months during spring.

Annual maximum > 1.6 m at least once every 10 years (for invertebrates) Poor Degrading water depth No less than 0.5 m more than once every 10 years (Froend et al. 1993).

No greater than 2.5 m for 2 consecutive years (Froend et al. 1993). Excellent Stable

> 6 consecutive months of inundation annually (Balla and Davis 1993; Briggs and Thornton 1999). Moderate Degrading

Period of Preferred earliest drying by April (wet year), Feb–Mar (medium year) or January (dry year) (DoE 2004). Moderate Degrading inundation/drying Permanent water present for not more than 2 consecutive years in every ten years (Crome 1988; Halse et al. Excellent Stable 1993; Davis et al. 2001).

Colour < 30 g 440 m-1 at all times Excellent Stable

Turbidity < 40 NTU at all times Excellent Stable

Salinity < 2,475 μS cm-1 during winter Moderate Stable pH > 7.0 (ANZECC 2000), < 9.0 (Davis et al. 1993) Good Stable

Chlorophyll a < 100 μg L-1 (Davis et al. 1993) Excellent Stable

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Components and Limits of acceptable change (LAC) Condition Score Trend processes

Nutrients TP < 100 μg L-1 (Davis et al. 1993), TN < 1,500 μg L-1 (ANZECC 2000) Poor stable

Littoral vegetation Current extent and biomass of native and exotic riparian vegetation unknown. NA - not monitored extent and condition Current area of lake bed encroached by Typha and other riparian vegetation unknown. NA - not monitored

Aquatic > 14 families during spring Moderate Stable invertebrates

Consideration should be given to climatic patterns and their potential effect on bird numbers.

Waterbirds Generally each lake should support: Stable to Moderate to good > 5,000 total waterbirds in 4 out of 5 years. degrading Breeding of 27 species a minimum of once every three years (lakes combined).

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19.8.4 Conservation objective

The conservation objective for the Forrestdale and Thomsons Lakes Ramsar site is:

Maintain the ecological character of the Forrestdale and Thomsons Lakes Ramsar site via the ongoing presence of the following characteristics:

o A regular cycle of wetting and drying. o Shallow water depths.

o Water quality that is not saline, acidic or eutrophic.

o Vegetation dominated by native plants.

o Suitable foraging, roosting and breeding habitat for water birds (incl. migratory species).

o Presence of Threatened Ecological Communities, rare and priority flora species, migratory shorebirds.

19.8.5 Analysis of relevant impacts

The following section discusses potential impacts to the Forrestdale and Thomsons Lakes Ramsar site. The Ramsar site does not intersect with the classes of action and will therefore not be subject to direct impacts. However, there are a range of potential indirect impacts that are relevant including those relating to potential changes to the ground and surface water regime and others associated with increased ‘people pressure’ to the site.

Impacts are assessed in accordance with the methodology described in Section 19.4 above.

Changes to groundwater and/or surface water

Introduction

The potential impacts to groundwater and/or surface water are examined within the scope of proposed development including:

 infrastructure; and  planned future urban, industrial and rural residential land within a 5 km radius of Forestdale and Thomsons Lakes Ramsar site.

The total areas of existing and proposed urban, industrial and rural residential development within the relevant areas that inform the assessment are given in Table 19-13.

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Table 19-13: Existing and proposed development around Forrestdale and Thomsons Lakes Ramsar site

Area within 5 km (ha) Urban Industrial Rural residential

Existing 6,431 1,556 2,889

Expansion 752 2,814 637

Future total 7,183 4,370 3,526

Given both Forrestdale and Thomsons Lakes are groundwater dependent ecosystems that are supported by the Superficial Aquifer, the assessment radius was defined to consider the hydrogeological properties of the aquifer. Any development outside this area is unlikely to have any indirect impact in relation to potential changes to surface water or groundwater at the lakes.

Forrestdale Lake is located in the City of Armadale Subarea in the Perth South Groundwater Area. There is no groundwater allocation plan for the Perth South Groundwater Area and the current limits were determined through an allocation limit review in 2008 (DoW 2008b). Current licensed entitlements in the City of Armadale Subarea are within the allocation limits. Licensed entitlements in other subareas in the Jandakot Groundwater Area near Forrestdale Lake are also within allocation limits.

Thomsons Lake is located in the Thomsons Subarea of the Cockburn Groundwater Area. The Cockburn Groundwater Area Allocation Plan, released in 2007, set the current allocation limits (DoW 2007a). Current licensed entitlements in the Thomsons Subarea are within the allocation limits. Licensed entitlements in other subareas in the Jandakot Groundwater Area near Thomsons Lake are also within allocation limits. All licence applications, even in subareas that are not fully allocated, are individually assessed to consider potential impacts to groundwater dependent ecosystems (DoW 2012b) and impacts are managed through licence conditions including the requirement to monitor groundwater levels and water quality where possible impacts are determined.

Both Forrestdale and Thomsons Lakes were studied as part of the Department of Water’s Perth shallow groundwater systems (SGS) investigation. This was a four year (2007 – 2010) program that focused on numerous wetlands situated on Gnangara and Jandakot groundwater mounds. Investigations at Forrestdale and Thomsons Lakes confirmed both lakes are groundwater dependent ecosystems that are supported by the Superficial Aquifer.

Key findings from the SGS investigation at Forrestdale Lake include (Bourke and Paton 2010):

 The lake is not a flow through lake but acts as drainage basin that captures local groundwater discharge and drainage.

 Local groundwater levels, and therefore groundwater discharge into the lake, are dependent on recharge by rainfall.

 In addition to rainfall, groundwater levels are also sensitive to changes in land use, drainage and abstraction.

 The Kardinya Shale that forms a confining layer between the Superficial and Leederville aquifers is absent beneath the lake so abstraction from the Leederville aquifer has the potential to impact on lake levels.

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 The risk of acidification due to oxidation of acid sulfate soils at Forrestdale Lake is minimised by the high buffering capacity of the sediments in the lake basin and high pH of the lake water.

Key findings from the SGS investigation at Lake Thomsons include:

 Thomsons Lake shows characteristics of a flow-through lake, with groundwater levels being higher than in the lake on the eastern (upgradient) side, and mostly lower than in the lake to the west.

 Thomsons Lake is in hydraulic connection with the regional groundwater flow system.

 Groundwater and lake water hydrochemistry are also clearly linked, indicating the dependence of the lake on groundwater within the Superficial Aquifer.

 The lake receives drainage water through a supplementation program that was initiated in winter 2004 and has continued every winter since.

Current Pressures

At Forrestdale Lake there has been a general trend in declining peak lake levels, reduced amount of time the lake is wet (hydroperiod) and earlier drying since 1992, due to reduced rainfall, groundwater abstraction and urbanisation. Local levels in the Superficial Aquifer have been relatively stable since monitoring commenced in 1996, though show a slight declining trend in minimum levels.

At Thomsons Lake there has also been a general trend in declining peak lake levels, reduced hydroperiods and earlier drying since 1992. This is again due to reduced rainfall, groundwater abstraction and urbanisation. This trend has been mitigated to some extent by the supplementation program initiated in 2004 (see below), which contributed to lake levels approaching target levels by supplementing water levels with water from surface drainage.

Local levels in the Superficial Aquifer have been relatively stable since 2007.

A drainage scheme diverts water from residential subdivisions to the east of Thomsons Lake, away from the lake in order to minimise changes to water levels and protect it from nutrient loading. The lake receives drainage water through a supplementation program that was initiated in winter 2004 and has continued every winter since. With agreement from the Water Corporation, water is diverted from the South Jandakot Branch Drain into Thomsons Lake by means of adjustable weir boards (Department of Conservation and Land Management 2006). Agricultural drains are used to direct drainage into Thomsons Lake from Kogolup South Eye and the area east of the lake. The drain from Kogolup South is still present but was blocked when pipes were laid between the two lakes (GB Hill & Partners Pty Ltd and WAWA 1990).

The Water Corporation maintains a network of main drains in the Forrestdale area (Forrestdale Main Drain and Berriga Main Drain). Forrestdale Lake is connected to Forrestdale Main Drain through an overflow outlet and water only flows rarely during flood events (Bourke and Paton 2010). There is also an extensive network of local authority and private drains in the area which were developed to reduce periods of inundation and water logging by restricting maximum groundwater levels. By restricting maximum groundwater levels these drains could also be impacting on lake levels.

James Drain flows towards Forrestdale Lake for three to four months of the year and drains surface water and groundwater (Coffey 2008). Skeet Drain also flows into Forrestdale Lake from Skeet Oval however the volumes of water are very low. Road drains in the area (Weld, Fisher and Moore) discharge to groundwater and do not flow directly into the lake (ERM 2000). According to locals of the

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area, the expansion of the Wungong dam in the late 1970s was largely responsible for reducing water levels in Forrestdale Lake, by reducing overflow from Wungong brook. Diversion of other surface water away from the lake during urbanisation and groundwater abstraction have also been cited as causes of lower lake levels since the 1970s (Giblett 2006).

Average maximum water depths from 1980 to 1999, the decades before and after the Ramsar site was listed, were 105 cm (range 38–206 cm) at Thomsons Lake, and 103 cm (range 47–187 cm) at Forrestdale Lake. Since 2000, average maximum water levels have declined 15 cm at Thomsons Lake (0–142 cm), and 63 cm at Forrestdale Lake (8–83 cm). The supplementation program at Thomsons Lake, has contributed to the smaller declines in average maximum lake levels compared to those at Forrestdale Lake.

The duration of time that water is present in Forrestdale and Thomsons Lakes is currently less than in the previous dry phase in the 1980s. Since 1998 both lakes have dried for at least five months each year. In 2013 both were dry for seven months. In some years since 2009 Thomsons Lake has dried for a shorter period than Forrestdale Lake. This may have been due to the influence of the supplementation program. In addition to drying for longer periods of time, Forrestdale and Thomsons Lakes are also drying out earlier than in previous years.

The altered hydrological regime has been attributed to reduced rainfall from climate change, groundwater abstraction and urban development.

Regarding water quality, both lakes have the potential to receive pollutants via ground and surface water. As per Section 19.8.3 however, water quality has generally been maintained despite development pressure in the surrounding area. Nutrient levels are considered to be moderately high.

Future pressures and risks (broad scale)

The risk assessment work undertaken by the Department of Water has identified future pressures and associated risks to groundwater resources at Forrestdale and Thomsons Lakes. These are summarised in Table 19-14 and then further discussed below.

Overall, high risks to groundwater quantity may result from abstraction for non-potable supply and garden bores, and alterations to drainage if less water enters the system.

Table 19-14: Summary of groundwater risk assessment for the Forrestdale and Thomsons Lakes Ramsar site

Potential impact Risk to quantity Risk to quality

Impacts from construction – temporary dewatering Medium Medium

Impacts from construction – activation of ASS NA High

Impacts from construction – contamination NA High

Removal of vegetation and increased developed footprint NA High

Licensed groundwater abstraction – potable (public water) Medium NA supply

Licensed groundwater abstraction – non-potable supply High NA

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Potential impact Risk to quantity Risk to quality

Groundwater abstraction that is exempt from licensing (garden High NA bores)

Alterations to drainage – more water entering system Potentially beneficial High

Alterations to drainage – less water entering system High Potentially beneficial

High risks to groundwater quality may result from increased penetration of nutrients and/or contaminants from activation of acid sulfate soils, construction contamination, and alterations to drainage if poor quality water is diverted into the system.

Impacts from construction present a medium to high future risk to the Forrestdale and Thomsons Lakes Ramsar site. This is because:

 It is possible that dewatering during the construction phase of developments in the surrounding area could lead to reduced ground and surface water levels and quality at the lakes. This assessment outcome is largely due to the proposed industrial development area to the immediate west and south of Thomsons Lake and the industrial development area south of Forrestdale Lake.

 Both lakes have been identified as having high risk of acid sulfate soils i.e. less than three metres from the soil surface (Swan Catchment Council 2004). This means that digging, dewatering, drainage or abstraction activities in the wider area that lower the water table and expose sulfidic sediments has the potential to cause considerable environmental damage at the lakes and is considered to present a high risk.

 Construction activities are considered to present a high risk to localised groundwater quality. Once the Superficial Aquifer has been contaminated, it can be very expensive and often impossible to remove the pollutant. Localised spills from industrial development can enter the groundwater system and then penetrate the lakes.

It is possible that the removal of vegetation (resulting in less evapotranspiration) and increased areas of urbanised land (where roof and road catchments channel rainwater into soak wells and stormwater basins) could increase the percentage of rainfall entering the Superficial Aquifer as recharge. This could increase groundwater and surface water levels and benefit the lakes, at which water levels are currently in breach of a number of hydrological LACs.

Though increased water levels would benefit the lakes, it is possible the removal of vegetation and increases in urbanisation through the proposed development could also increase the volume of poor quality water (including nutrient enriched water) entering the Superficial Aquifer. Nutrient contamination is primarily from fertilised rural and urban lands. Nutrients from land uses adjacent to lakes can be transported in groundwater and lead to reduced surface water quality. The potential impacts of increased volumes of nutrient rich water entering the Superficial Aquifer are considered to be major. This level of assessment is considered appropriate because both lakes are already moderately nutrient enriched and any decline could lead to the water quality LACs at the lakes being breached more often with long term consequences for their ecological character.

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Regarding abstraction of groundwater for non-potable supply, it is possible that cumulative impacts of ongoing increases in groundwater abstraction from the Superficial Aquifer for non-potable supply associated with the proposed development (e.g. for the irrigation of public open space) will lead to reduced groundwater levels and surface water levels at the lakes. The potential impacts of increased groundwater abstraction are considered to be major, as a number of hydrological LACs associated with low water levels are already being breached on an ongoing basis due to abstraction and reduced rainfall. Any increase in these breaches has the potential to result in long term consequences for the ecological character of the lakes and require a significant management response to remediate.

For potable supply, it is unlikely that cumulative impacts of ongoing increases in groundwater abstraction from the Superficial or Leederville aquifers associated with proposed development will lead to reduced groundwater levels and surface water levels at the lakes. This is because future increases in demand for potable water are likely to be met using sources other than groundwater, such as seawater desalination and groundwater replenishment.

Regarding the abstraction of groundwater for activities that are exempt from licensing activities (e.g. garden bores), it is possible that future urban development will lead to a cumulative increase in groundwater abstraction from the Superficial Aquifer. This could possibly result in a reduction of groundwater levels and surface water levels at the lakes. This may also lead to more water level LACs being breached on an ongoing basis. Given a number of hydrological LACs associated with low water levels are already being breached, the potential impact of increased groundwater could have significant, long term consequences for the ecological character of the lakes.

The modification of surface drainage and installation of sub-surface drainage in urban and industrial development surrounding the lakes has the potential to induce both positive and negative impacts at Forrestdale and Thomsons Lakes. Depending on the design, it is possible that alterations could increase or decrease the volume of drainage water entering the lakes. An increase in the volume of drainage water entering the lakes could have a positive impact on surface water levels and lead to a number of hydrological LACs being met more often. However, it could also lead to increased nutrient concentrations in surface water at the lakes and contribute to more water quality LACs being breached. This could have major, long term consequences for the ecological character of the lakes and therefore represents a high risk to their ecological character.

Conversely, it is possible that a decrease in the volume of drainage water entering the lakes could have positive impact if it meant that less nutrient enriched water entered the lakes. However, it could also have a negative impact on surface water levels and lead to more hydrological LACs being breached. Given a number of hydrological LACs associated with low water levels are already being breached, the potential impact of alterations to drainage that decrease the volume of water entering the lakes could have major, long term consequences for their ecological character and therefore represents a high risk to their ecological character.

Future pressures and risks (specific expansion areas)

Using the methodology described in Section 19.5.4, Figure 19-4 shows the nutrient enrichment risk attributed to each of the proposed new urban, industrial and rural residential areas within 5 km of the Forrestdale and Thomsons Lakes Ramsar boundary. Locations that have high risk are likely to require more management than low-risk areas.

This risk rating should be considered in the context of the future proposed land use. Different land uses are associated with varying nutrient export risks owing to differences in nutrient inputs and transport

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pathways. For example, where industrial areas are connected to the sewer, depending on the specific industry, nutrient export risk is likely to be low. Urban and rural residential may be higher owing primarily to fertiliser application and in the case of rural residential septic tanks or ATU’s.

There are areas of all three future land uses (urban, industrial and rural residential) in high phosphorus export risk areas within 5 km of the Forrestdale and Thomsons Lake Ramsar boundary. Of particular note are the urban and industrial areas in close proximity to Forrestdale Lake.

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Figure 19-4: Phosphorus Risk for Urban, Industrial and Rural Residential Expansion areas within 5km of Forrestdale and Thomsons Lakes

Legend Urban Strategic Assessment Area Forrestdale & Thomsons Lakes 5km Buffer Phosphorus Risk 0-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10 Industrial

Rural Residential

0 3.5 7

Kilometres Datum/Projection: GDA 1994 MGA Zone 50 Data Source: DoW (2015) Prepared by: SM Date: 19/11/2015 ± Strategic Assessment for the Perth and Peel Regions

Increasing people pressures

Current pressures and risks

Although Forrestdale and Thomsons Lakes are primarily reserved for nature conservation purposes, passive recreation that does not impact on natural values or ecosystems of the reserve is permitted. Contemporary uses of the Ramsar site include bird-watching, nature walks, horse riding and general recreation.

Access is more restricted at Thomsons Lake due to the presence of a vermin proof fence around the perimeter of the reserve. Horse-riding occurs on an external trail that runs around some of the perimeter of the Forrestdale Lake Nature Reserve (CALM, 2005a) and on trails on the adjoining recreation reserve, and outside of the vermin proof fence at Thomsons Lake (CALM, 2005b).

Current adjacent land use at Forrestdale and Thomsons Lakes includes urban development and rural- living blocks.

Currently, the greatest threats to the values of the lakes from visitor access are from uncontrolled and unauthorised access by horse and trail bike riders. These activities cause trampling and grazing of plants, spreading weeds and disease, disturb native fauna, and result in soil compaction and erosion. Excessive disturbance of waterbirds by humans and dogs may also occur, especially in summer and autumn when the lake is drying out. Rubbish dumping can also be an issue.

Unplanned fire (i.e. in the context of recreational use, due to arson) is a significant threat to the natural values of the lakes. Infestations of Typha orientalis are fire hazards because fires in these bulrushes are difficult to control and can cause damage to fringing vegetation. Frequent wildfire in wetland areas will also prevent the establishment of paperbark vegetation and will lead to an even greater domination of Typha. Fire activity also encourages the invasion of Typha in wetland areas because it regenerates more rapidly than local rush species.

Future pressures and risks

The risk assessment work undertaken by Parks and Wildlife has identified future ‘people pressures’ to ecological values at the Forrestdale and Thomsons Lakes Ramsar site and their relative risk levels. These are summarised in Table 19-15 and Table 19-16 and then further discussed below.

Table 19-15: Summary of people pressure risk assessment for Forrestdale Lake

Potential impact Risk to littoral vegetation Risk to shorebirds

Access (unlawful) – vehicles, Medium to high – physical Low (horses) horse-riders disturbance; weeds & dieback Medium (vehicles)

Access (lawful) – pedestrians, Low to medium – physical High (pedestrians with dogs) horse-riders disturbance; weeds & dieback Low (horses)

Bird watching NA Low

Very high (disturbance) Increased dogs and cats NA Medium (predation)

Fire – arson High – physical disturbance, death NA

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At Forrestdale Lake high risk to littoral vegetation can result from unlawful access by vehicles and horse-rider and arson. High risk to shorebirds can result from pedestrians with dogs and from increasing numbers of dogs and cats accessing the reserve from adjacent properties. At Thomsons Lake increasing numbers of dogs and cats accessing the reserve from adjacent properties also presents a high risk to shorebirds, while arson presents a high risk to vegetation.

Illegal access is likely to have considerable future impacts to the ecological character of the Forrestdale Lake portion of the Ramsar site, unless appropriate measures can be put in place to prevent illegal access to the site. Trail bikes and horse-riders (off trail) have the potential to cause considerable damage to littoral vegetation and other ecological communities. Both activities are also known to spread weeds and dieback, although horses to a lesser degree. Currently, the full condition of the site’s vegetation is unknown (i.e. no data to support an assessment against vegetation LACs), however declines in vegetation condition and expansion of Typha have been observed. This makes any future activities that may exacerbate declines in condition (damage, weeds, dieback) of concern.

Pedestrians and horse-riding on designated trails have a lesser potential to impact on vegetation and are considered to present a low to medium risk. However, pedestrians with dogs present a high risk to shorebirds due to their disturbance potential. Shorebirds are also at very high risk from increased numbers of dogs and cats associated with increased urban development. These species are known to both disturb and prey on shorebirds/waterbirds and their eggs/young. The number of waterbirds and number of species recorded at both Forrestdale and Thomsons Lakes have been variable, but appear to have declined in recent years. This makes any activities that directly disturb birds or lead to declines in the condition of their habitat of concern.

Arson presents a high risk to the littoral vegetation at Forrestdale Lake, both directly and indirectly. The predicted frequency of arson is expected to increase with greater usage of the site and surrounding urban populations. Damage and death of vegetation is a direct result of fire. The impact of arson may also be exacerbated through the interaction with weed infestation, particularly Bulrush Typha orientalis colonisation, as fires are difficult to control where this species dominates and fire allows even greater domination of the species.

Table 19-16: Summary of people pressure risk assessment for Thomsons Lake

Potential impact Risk to littoral vegetation Risk to shorebirds

Access (unlawful) – vehicles, horse Medium – physical disturbance; Low riding weeds & dieback

High (disturbance); Medium Increased dogs and cats NA (predation)

Fire – arson High – physical disturbance, death NA

Thomsons Lake is at less risk from increased recreation and population pressures due to a vermin proof fence being constructed around Thomsons Lake Nature Reserve in 1993. Risks to vegetation and shorebirds from access are considered low to medium. However, similar concerns regarding the risk from increased numbers of dogs and cats and arson apply to Thomsons Lake in the same was as they do for Forrestdale.

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19.8.6 Mitigation and management

Changes to groundwater

Construction

Risks to water quality from construction activities can be effectively avoided and mitigated using best practice construction environmental management controls. These controls are currently and will continue to be requirements of development approvals. Action Plan F includes an over-arching conservation commitment around the continued implementation of these measures.

Examples of such controls include:

 Construction Environment Management Plans (CEMPs);

 Acid Sulfate Soil Management Plans;  Sediment and Erosion Control Plan;

 spill response procedures; and

 appropriate storage and stockpiling of oils, greases, heavy metals and other potential contaminants.

Groundwater abstraction

As for Becher Point Ramsar site, a significant future risk to the groundwater regime of the Forrestdale and Thomsons Lake Ramsar site is increased groundwater abstraction for non-potable supply (e.g. for irrigation of new areas of public open space) and garden bores. These risks can be successfully managed and mitigated via the appropriate application of the planning process. This process is led by the Department of Water and involves a range of measures as discussed below.

The Department of Water will continue to manage groundwater abstraction in accordance with the requirements of the Rights in Water and Irrigation Act 1914 and Ministerial Statement No. 688. Groundwater allocation limits (that include estimates of exempt use) and licensing on the Jandakot groundwater system are managed in line with conditions and commitments set in Ministerial statement 688 that aim to protect significant environmental values supported by the system, including Forrestdale and Thomsons Lakes (Government of Western Australia 2005).

Any ongoing abstraction for non-potable or potable supply requires a licence under the RIWI Act. For a licence to be granted, there must be water available under the allocation limit in the subarea in which the proposed development is located. There is currently water available for general licensing in all subareas in the vicinity of the lakes other than Valley, Airport, South Lakes and Wright subareas. Any licensing requirements associated with the proposed development in these subareas would rely on licence transfers through the development process or on licence trades. There is also currently some water available for public water supply from the Jandakot groundwater area.

Volumes currently licensed within the proposed development area could be transferred for use as water for public open space so that abstraction does not increase as the areas are developed. As the areas are developed, opportunities to reduce licensed groundwater use through licence transfers and maximum efficiency of water for public open space should be explored.

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Any development within the Jandakot Underground Water Pollution Control Area will be guided by State Planning Policy 2.3 - Jandakot Groundwater Protection Policy which ensures land use change is compatible with long-term priority use of groundwater for public water supply and restricts activities that may cause groundwater contamination.

Alterations to drainage

Ideally, any alterations to drainage infrastructure associated with proposed developments should aim to help maintain surface water levels and quality at the lakes. Potential impacts associated with alterations to drainage are required to be addressed through the planning process. Detailed design considerations for subsoil drainage are given in water resource considerations when controlling groundwater levels in urban development (DoW 2013).

Drainage water, diverted from the South Jandakot Branch Drain into Thomsons Lake by means of adjustable weir boards, has been used successfully to supplement water levels since 2004 (CALM 2006a). The program contributed to lake levels in 2013 and 2014 approaching the target level of 12.6 m AHD and has not resulted in increased nutrient concentrations in surface water. Water levels at Forrestdale Lake could benefit from a similar supplementation program. An investigation for such a program should also assess whether local authority or private drains in the area are restricting maximum groundwater levels and in turn impacting on lake levels. It should also identify drainage or land use adjacent to the lake that may be contributing to its nutrient concentrations. Any alterations to drainage at Forrestdale Lake would be managed under the under the Southern River Integrated Land and Water Management Strategy (DoW 2009b) and the Forrestdale main drain arterial drainage strategy (DoW 2009c).

Thomsons Lake’s regional drainage infrastructure is managed by the Water Corporation under the South Jandakot Drainage Management Plan (GB Hill and Partners 1990). The drainage scheme is managed in line with conditions and commitments in Ministerial Statement No.’s 45 and 467 set under the Environmental Protection Act which include implementing relevant components of the Environmental Management Programme for the South Jandakot Drainage Scheme (GB Hill and Partners and WAWA 1990) and monitoring the environmental performance of the scheme. Alterations to the drainage infrastructure at Thomsons should require a review and update of the South Jandakot Drainage Management Plan and associated Ministerial statements.

Other management measures

The Department of Water will continue to:

 monitor water levels (groundwater and surface water) and water quality at the lakes;

 monitor wetland vegetation and macroinverebrates;  report on condition at the lakes against criteria in Ministerial Statement No. 688 to the Office of Environmental Protection Authority;

 distribute annual public water supply licensing considering condition at the lakes;

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 undertake compliance inspections and meter audits to ensure groundwater use is within licence entitlements;

 work with local government and other licencees to improve water use efficiency including design and maintenance of public open space;

 determine appropriate areas for and implement water restrictions on the use of garden bores;  regularly review allocation limits through an adaptive management process; and

Increasing people pressures

The required management approach to successfully addressing potential impacts from recreational use of the Forrestdale and Thomsons Lakes Ramsar site is two pronged. Measures are required to:

 prevent and discourage unlawful access to the site and illegal activities (i.e. arson); and

 facilitate managed recreation opportunities so that people can enjoy the values of the site through passive recreation that has been designed in such a way as to avoid and minimise impacts.

Management actions at the Forrestdale and Thomsons Lakes Ramsar site are currently guided by the Forrestdale Lake Nature Reserve Management Plan, Thomsons Lake Nature Reserve Management Plan and Beeliar Regional Park Management Plan. It is intended that future management of the area will continue to be embedded in formal park management plans (the coverage and configuration of these may change over time). Key requirements of the future management regime are:

 Upgrades and extension of fencing, including adding additional strength fencing to combat unlawful damage at Forrestdale Lake and ongoing maintenance of vermin proof fence at Thomsons Lake.

 Construction of two bird hides and associated paths and boardwalks to facilitate passive recreation and reduce the need for unlawful vehicle access to experience the Ramsar site. Proposed infrastructure includes interpretation shelters, signage and seating. Signage should also include messaging that all dogs must be on leads within the sites.

 Rehabilitation of wetland and adjacent banksia woodland vegetation complexes including weed control and implementation of feral animal control programs.

 Removal of unlawfully dumped rubbish and construction material following the extensions and upgrades to fencing.

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Conservation commitments

The following conservation commitments for the Forrestdale and Thomsons Ramsar site are provided in the Strategic Conservation Plan. They have been developed to address the key risks identified in this assessment and support the broader management regime that exists for the site.

The conservation commitments are:

 Implement a monitoring program that includes the limits of acceptable change.

 Conduct an investigation into a potential stormwater supplementation program for Forrestdale Lake to identify limits of acceptable change, incorporate findings into adaptive management arrangements and future planning.

 Implement management arrangements to further conserve the ecological characteristics of the wetland, including fencing extension and upgrades, construction of passive recreation facilities, vegetation rehabilitation, fauna management and rubbish removal.

19.8.7 Outcome for the Forrestdale and Thomsons Lakes Ramsar site

This assessment has identified the following key issues relevant to the outcome for the Forrestdale and Thomsons Lakes Ramsar site:

 There will be no direct impacts to the site from the classes of action, however indirect impacts to water resources and ecological values from increased people pressure are possible.

 Groundwater abstraction from the Superficial aquifer for non-potable supply and garden bores; as well as alterations to drainage present a future potential high risk to groundwater quantity.

 Impacts from construction, removal of vegetation and alterations to drainage present a future potential high risk to groundwater quality.

 At Forrestdale Lake pressures from unlawful access (vehicles, horse-riding) and arson pose a potential high risk to vegetation, while pedestrians (with dogs) and increased numbers of dogs and cats pose a potential high risk to shorebirds.

 Thomsons Lake is at less risk from increased recreation and population pressures due to a vermin proof fence. However, arson and increased numbers of dogs and cats pose a potential high risk to vegetation and shorebirds respectively.

 The majority of risks to groundwater of the sites can be effectively managed under existing management and regulatory regimes. This will rely on the Department of Water continuing to manage groundwater abstraction and licencing and pursuing opportunities to strengthen controls on garden bores (a conservation commitment is provided around this issue). This also assumes best practice construction controls and regulation by local government.

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 Risks to groundwater from alterations to drainage require additional commitments, including an investigation into whether Forrestdale Lake would benefit from water supplementation. A conservation commitment is provided around this issue.

 Management of the ecological values of the site relies on measures to prevent and control access and fire and to better facilitate recreational activities. This is best achieved under the strategic direction of a management plan (currently the Forrestdale Lake Nature Reserve Management Plan, Thomsons Lake Nature Reserve Management Plan and Beeliar Regional Park Management Plan). Actions required include fencing extension and upgrades, construction of passive recreation facilities, vegetation rehabilitation, fauna management and rubbish removal. A conservation commitment is provided around this issue.

Based on the current understanding of future risks and the existing and future ability to manage these, the overall outcome for the Forrestdale and Thomsons Lakes Ramsar site is considered acceptable and is one that meets the conservation objectives. It is anticipated that the ecological character of the Ramsar site will be maintained in parallel with the implementation of the classes of action.

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19.9 THE PEEL-YALGORUP SYSTEM

19.9.1 Description of the wetland

Introduction

The Peel-Yalgorup System Ramsar site was originally nominated as a Wetland of International Importance in 1990. The site is located approximately 80 km south of Perth within the Swan Coastal Plain bioregion (Table 19-4). It covers more than 26,000 ha and spans four municipal boundaries - City of Mandurah and the Shires of Waroona, Murray and Harvey.

The Peel-Yalgorup System is a large and diverse system of shallow estuaries, coastal saline lakes and freshwater marshes. The Ramsar site includes:

 The Peel Inlet and Harvey Estuary, which lies on the western edge of the Swan Coastal Plain. The estuarine system consists of two interconnected shallow lagoons, (which are the Peel Inlet and the Harvey Estuary), into which the Murray, Serpentine and Harvey Rivers discharge and the estuarine portions of those rivers as defined by saltwater penetration.

 Lake McLarty and Lake Mealup, which are shallow, moderate sized wetlands on the plain to the east of the Harvey Estuary. Lake McLarty has no natural surface water drainage channels (although there is a drainage channel to the south that has the potential to overbank into the wetland). The dominant water source is groundwater and the lake intersects the shallow, surficial fresh groundwater aquifer.

 Ten elongated coastal saline wetlands inside the Yalgorup National Park. The lakes are approximately 600 m from the Harvey Estuary separated from the estuary by a fossil dune ridge. The lakes have no inflow or outflow channels. Inflows are from direct precipitation, localised run off and groundwater.

Key features of the Ramsar site are summarised below. A detailed description is provided in Appendix D as well as in the Ramsar Information Sheet and Ecological Character Description (Hale and Butcher 2007).

 The Peel Inlet and Harvey Estuary are large shallow estuarine waters fed by the Serpentine, Murray and Harvey Rivers, and are connected to the Indian Ocean by the Mandurah and Dawesville channels.

 Lake McLarty and Lake Mealup are seasonal freshwater to brackish wetlands. The Yalgorup National Park wetlands are brackish to hypersaline. The wetlands are shallow and fed mainly from groundwater and rainfall. The site is fringed mainly by samphire, rushes and sedges and paperbark communities.

 The Yalgorup Lakes are a group of mostly permanent wetlands which include Lake Clifton, one of the few places in the world where living Thrombolites occur in inland water. Thrombolites are underwater rock-like structures that are formed by the activities of microbial communities. They are actively growing and rely on an inflow of carbon-rich groundwater. In Lake Clifton the Thrombolites are considered to be over 2,000 years old.

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 The Peel-Yalgorup System Ramsar site is the most important area for waterbirds in south-western Australia. It supports a large number of waterbirds and a wide variety of waterbird species. It also supports a wide variety of invertebrates, and estuarine and marine fish.

 Licensing for groundwater abstraction in the Peel-Harvey coastal plain catchment is guided by the Peel Coastal, Murray and Serpentine Groundwater Allocation Plans (DoW 2014, 2012a, under development).

 The Peel-Yalgorup Ramsar site is of importance to the regional economy and has a number of important social and cultural values.

Dawesville Channel

The single most influential factor in the recent history of the Ramsar site has been the construction of the Dawesville Channel completed in 1994. As early as the 1970s and continuing through to the early 1990s, the system suffered the effects of eutrophication, predominantly due to inputs of phosphorus from the catchment. This resulted in an increase in algal growth, and of particular concern, blooms of the potentially toxic cyanobacterium, Nodularia. A three part action strategy to address the problems of eutrophication in the estuary was developed (EPA1994) and included measures to:

 reduce nutrient run-off from the catchment;  continue harvesting of macroalgae as necessary; and

 increase flushing to the ocean.

The third of these was achieved by the construction of the Dawesville Channel, which connects the estuary to the Indian Ocean near the junction of the Peel Inlet and Harvey Estuary. The increased flushing provided by the Channel, was predicted to eliminate Nodularia blooms, increase dissolved oxygen concentrations, improve water clarity and stabilise salinity (EPA 1994). The Channel is 2.5 km long, 200 m wide and between 4.5 and 6.5 m deep and has associated canal developments that have been constructed over the last 15 years.

The increased connection to the marine environment has resulted in fundamental and permanent changes to ecological components of the Peel-Harvey Estuary. Attributes such as hydrology and water quality have changed significantly and had effects on the biotic components of the system. With increased exchange with marine waters, water quality in the estuarine basins has improved, particularly in the Harvey Estuary where periods of stratification and deoxygenation are shorter and less frequent. Nodularia blooms have been absent and turbidity during spring has decreased. In contrast to pre- Channel years, water quality in the Harvey Estuary has become very similar to that in the Peel Inlet.

While there can be no doubt that the Peel-Yalgorup System remains a wetland of international importance and that it continues to meet the Ramsar criteria under which it was listed (Lane et al. 2002), management of the system must be consistent with this new environment. For this reason, the current ecological character description based on changes summarised in Hale and Butcher (2007), is the benchmark against which future change should be measured.

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Figure 19-5: Peel-Yalgorup System Ramsar Site

Mandurah !H

Pinjarra !H

South Metro Peel

Waroona !H

Legend

Strategic Assessment 0 6 12 Area Kilometres Datum/Projection: Ramsar Wetland Sub- GDA 1994 MGA Zone 50 group: Data Source: DPaW Peel-Yalgorup System Prepared by: JL Date: 19/11/2015 ± Strategic Assessment for the Perth and Peel Regions

Social and cultural values

In addition to its environmental values, the Peel-Yalgorup Ramsar site plays a significant role in both the economy and the social and cultural fabric of the region.

Sea mullet, yellow eye mullet, yellow-fin whiting, Australian herring, tailor, cobbler, King George whiting, and Perth herring are eight of the 28 species reported in commercial fishery landings from 1999-2013 in the Peel-Harvey estuary. There are 11 licenced fishers in the estuary, with all of them active in 2013. Total catch value (wholesale) is currently between $2 and $3 million per year.

The long-term stability of the trend in the standardised catch per unit effort of two key species in the Peel-Harvey estuarine fin fishery (cobbler and sea mullet) suggests stock abundance is stable (Fletcher and Santoro 2014). Cobbler catch rates have improved since the last ecological character description (Hale and Butcher, 2007), whilst sea mullet has continued to fluctuate at similar levels over the last ten years.

Blue Manna crabs are considered a key species in the region for their value in recreational fishing, and to a lesser extent, commercial fisheries which in 2005-06 was worth $13.7 million to the local economy (Peel-Harvey Catchment Council, 2009). There are currently a number of management measures in place for recreational fishing of crabs to reduce impacts of over-fishing, including but not limited to: bag and boat limits; restrictions on catch condition and size; and seasonal closures of the fishery within the Peel-Harvey Estuary.

Tourism in the Peel region contributes approximately $150 million annually to the region, with both domestic and international visitors. The most popular recreational and tourism activities associated with the Ramsar site include: bushwalking, bird watching, camping, fishing, boating, crabbing, water skiing, canoeing, kayaking, kite surfing, sailing, wake boarding and swimming (URS 2007).

Throughout the Ramsar site there is a range of infrastructure that is available for recreation and tourism managed by Parks and Wildlife and Local Government Authorities. This includes camping facilities Martin Tank Lake and Herron Point on the Harvey Estuary, and key day use sites including the Thrombolite Boardwalk, Lake Hayward and Island Point. Parks and Wildlife also manage a series of bird hides to watch shore and migratory birds visiting the Ramsar site including at Lake Pollard in Yalgorup Nation Park, Creery Nature Reserve and Samphire Cove Nature Reserve.

The estuarine and river waterways of the Peel-Yalgorup Ramsar site provide one of the most popular recreational boating and fishing environments in WA. The area contains a range of public and private jetty facilities, including commercial tour operators, boat and house boat hire and private recreation vessels. The more sheltered estuary and river environments provide conditions suitable for boating over longer periods than more exposed ocean environments and the opening of the Dawesville Channel has increased access to the estuary for both a greater number and larger vessels. The Peel Region Recreational Boating Facilities Study (Department of Transport, April 2011), which covered the City of Mandurah and the Shires of Murray and Waroona, identified that:

 The Peel Region has a very high ratio of recreational boat ownership per head of population, at 101.7 per 1,000 for 2009. Based on predicted trends this is forecast to rise to 120.9 per 1,000 at 2031.

 Department of Fisheries observations are that on a good boating day approximately 50 per cent of the boats on the water in the Peel Region will be visitors from elsewhere, predominantly the greater Perth Metropolitan Region (Department of Fisheries, 2001).

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The Peel-Yalgorup System Ramsar site lies within Pinjarup country, a dialect group of the Nyoongar Native Title claimants. As with other Indigenous Australians, Pinjarup people were strongly connected to each other, their culture and their country through the Dreaming. In southwest Australia, water is of special significance and the ‘Waugal’ is the creative and life-giving being associated with all freshwater sources, surface and ground. Although dormant most of the time, the Waugal may cause immense harm if disturbed. Hence all fresh water-bodies may be considered to be highly significant mythological sites, with certain areas having particular significance as a place where the Waugal enters or exits the ground, or where it rests (Dortch et al. 2006).

There are over 356 sites of aboriginal significance in the Peel-Harvey Catchment and 27 specific sites on the Peel-Harvey Estuary have been identified for the proposed heritage trail (Dortch et al. 2006). This includes sites of artefact scatter, camp sites, ceremonial sites, fish traps, skeletal remains and sites of mythological significance.

Current management arrangements

The current management arrangements within the Peel-Yalgorup System Ramsar site are complex. They consist of:

 a number of government agencies (State and Local) who hold land within the site;

 a number of government agencies with responsibilities in relation to waterways;  land owned privately (Lake Mealup Preservation Society); and

 an extensive network of community groups (with varying roles and responsibilities) undertaking conservation, monitoring and research, and education activities within the Ramsar site.

A brief summary of the current management arrangements is provided in Table 16 below with more details available in Appendix D.

Table 19-17: Summary of existing management arrangements for the Peel-Yalgorup System Ramsar site

Agency / group Responsibility

Manages lands within the Ramsar site that are vested within the Conservation Commission of Western Australia under the CALM Act, including the Yalgorup National Park that contains Parks and Wildlife all of the Yalgorup Lakes and multiple nature reserves and conservation parks that fringe the Peel-Harvey Estuary, including Lake McLarty and a portion of Lake Mealup. Manages Lake Clifton Thrombolite community in accordance with the Interim Recovery Plan.

Manages groundwater use primarily via allocation limits and groundwater licences (as regulated under the Rights in Water and Irrigation Act 1914). Manages surface water use via allocation limits, surface water licences and permits to interfere with the beds and banks of watercourses and wetlands in the Murray River System surface water area, which is proclaimed under the Rights in Water and Irrigation Act 1914. Department of Water Manages the legislative requirements of the Waterways Conservation Act 1976, created for the purpose of conservation and management of certain lands, as well as the Waterways Conservation Regulations 1981 in the Peel Inlet management area. Licenses dredging, reclamation, dewatering and excavation in the waterway, including for retaining walls, jetties, private boat ramps and public facilities. The functions of the Minister include considering public amenity and having regard for maintaining public access in the

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Agency / group Responsibility management area. Is responsible for developing strategies and management plans to protect the quantity and quality of water resources and providing advice on flood management to land planners and local government. Consults the Department of Parks and Wildlife’s Ramsar coordinator when developing water resource management plans that may impact on the Ramsar site. Manages several foreshore reserves in and around the Ramsar site.

Is responsible for conserving, developing and managing fish and aquatic resources. Manages and licenses commercial and recreational fishing activities within the Ramsar site, Department of through compliance and community education. Fisheries Responsible for providing scientific knowledge and advice to support the conservation and sustainable use of the State’s aquatic resources. Lead agency for aquatic biosecurity.

Is responsible for marine safety and the provision of coastal facilities such as jetties and Department of moorings. This includes managing designated water ski areas, launching ramps and jetties, Transport moorings, boating prohibited areas, boating speed restrictions, navigation aids and dredging within the Ramsar site.

Local government – City of Have land management responsibilities for conservation and recreation reserves inside or Mandurah and adjacent to the Ramsar site. Shires of Murray, Manage most boat ramps and navigational channels. Waroona and Harvey

Is an incorporated, not-for-profit, community based Natural Resource Management Peel-Harvey organisation that promotes an integrated approach to catchment management and protection Catchment and restoration of the environment within the Peel-Harvey catchment. Council (PHCC) Coordinated the development of the Ecological Character Description.

Owns three freehold lots within and adjacent to the Peel-Yalgorup Ramsar site. The Mealup properties are subject to conservation covenants through the National Trust of Australia (WA) Preservation and are managed by the Society in accordance with a management plan for the covenanted Society Inc. bushland.

Support the planning and implementation of on-ground activities conducted by Local Government, private landholders and community groups on public land e.g. revegetation, Landcare Centers streamlining (fencing and revegetation of riparian areas), protection of bushland, weed control, litter removal and wetland enhancement.

Other community Groups include Peel Preservation Group, Lake Mealup Preservation Society, Men of Trees groups and the Mandurah Bird Observers Group and BirdLife Australia (Peel).

19.9.2 Ramsar listing criteria

The current listing criteria, taken from the Ramsar Information Sheet (RIS) for the site are presented in Table 19-18. A history of how the site has been listed is provided in Appendix D.

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Table 19-18: Ramsar listing criteria and justification for the Peel-Yalgorup System

Criterion Justification

1. A wetland should be considered The site includes the largest and most diverse estuarine complex in south- internationally important if it contains a western Australia and also particularly good examples of coastal saline representative, rare, or unique example lakes and freshwater marshes. of a natural or near-natural wetland type found within the appropriate biogeographic region.

3. A wetland should be considered The site is one of only two locations in south-western Australia and one of internationally important if it supports very few in the world where living Thrombolites occur in inland waters. populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region.

4. A wetland should be considered The basic description of this criterion implies a number of common internationally important if it supports functions/roles that wetlands provide and the following apply at the Peel- plant and/or animal species at a critical Yalgorup System Ramsar site, in most if not all cases both at the date of stage in their life cycles, or provides listing and at present: refuge during adverse conditions. • the critical life stage of migration: annual use by large numbers of many species of migratory animals; • the critical life stage of drought refuge: seasonal influx of large numbers of waterbirds from dried out wetlands in surrounding areas, and periodic massive influx from wider regions during drought; • the critical life stage of breeding: regionally and nationally significant colonies of cormorants occurred in the 1980s in paperbark swamp in “Carraburmup Swamp Nature Reserve” (Jaensch et al. 1988) on the south-east side of Peel Inlet (and part of the Ramsar site) and small breeding colonies of pelicans breed now and then on islets in Peel Inlet; in addition, the Yalgorup Lakes are a significant site bioregionally for breeding of Hooded Plover; • breeding also applies to fishes, crabs and prawns; and • the critical life stage of moulting: Shelduck and Musk Ducks that congregate on the open waters of the Ramsar site outside the breeding season are engaging in moult (hence, the birds are flightless for a short period).

5. A wetland should be considered The site comprises the most important area for waterbirds in south-western internationally important if it regularly Australia, supporting in excess of 20,000 waterbirds annually, with greater supports 20,000 or more waterbirds. than 150,000 individuals recorded at one time (February 1977). Numbers exceeding 20,000 birds have been recorded in all comprehensive surveys conducted in the 1990s in the Peel-Harvey Estuary.

6. A wetland should be considered According to the 5th edition of Waterbird Population Estimates internationally important if it regularly (http://www.wetlands.org/WatchRead/Currentpublications/tabid/56/mod/157 supports 1% of the individuals in a 0/articleType/ArticleView/articleId/3376/Waterbird-Populations-Estimates- population of one species or Fifth-Edition.aspx), the site regularly supports 1% of the population of: Red- subspecies of waterbird. necked Avocet (Recurvirostra novaehollandiae), Red-necked Stint (Calidris

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Criterion Justification ruficollis), Red-capped Plover (Charadrius ruficapillus), Hooded Plover (Thinornis rubricollis), Black-winged Stilt (Himantopus himantopus), Banded Stilt (Cladorhynchus leucocephalus), Curlew Sandpiper (Calidris ferruginea), Sharp-tailed Sandpiper (Calidris acuminata), Fairy Tern (Sternula nereis), Musk Duck (Biziura lobata), Grey Teal (Anas gracilis), Australasian Shoveler (Anas rhynchotis), Australian Shelduck (Tadorna tadornoides) and, Eurasian Coot (Fulica atra).

8. A wetland should be considered The Peel-Yalgorup System Ramsar site is important as a nursery and/or internationally important if it is an breeding and/or feeding ground for at least 50 species of fish, the Western important source of food for fishes, King Prawn (Penaeus latisulcatus) as well as the commercially significant spawning ground, nursery and/or Blue Swimmer Crab (Portunus pelagicus). In addition, the Peel-Harvey migration path on which fish stocks, Estuary is a migratory route for the Pouched Lamprey (Geotria australis). either within the wetland or elsewhere, depend.

Note – the Thrombolite (microbialite) Community of a Coastal Brackish Lake (Lake Clifton) was listed under the EPBC Act as critically endangered in January 2010. This listing means the site also meets Ramsar Criteria 2 - A wetland should be considered internationally important if it supports vulnerable, endangered, or critically endangered species or threatened ecological communities.

19.9.3 Current condition

Overall the current condition of the Peel-Yalgorup Ramsar site is mixed, but despite this, the site retains most of those values recognised in all six of the criteria from the 2007 review of the Ramsar Information Sheet (note: for the Western King Prawn there is insufficient information available to assess).

The wetland habitat remains suitable to support high numbers of waterbirds in all parts of the system with perhaps the exception until June 2012, being for Lake Mealup, where all species counts had declined. Recent restoration of near natural hydrological regime, and aquatic vegetation through the redirection of the Mealup Main drain into Lake Mealup should facilitate a return to expected populations of waterbirds in that wetland. The Shorebird 20-20 data confirms that habitat within the components of the Peel-Yalgorup system remains suitable to support high numbers of waterbirds with numbers across the entire Peel-Yalgorup System Ramsar site being greater than 20,000 for all six years of monitoring 2008-2013 and a maximum count in 2013 of over 90,000 waterbirds was recorded.

Assessment against LACs highlights that many of the LACs are being met in the majority of years. However, the assessment also shows that LACs for a number of key components and processes are either never being met, or not being met in the majority of years. These components and processes include:

 Nutrients (Total-P, Total-N, NOx) - particularly in the Serpentine and Murray Rivers, Goegrup Lake, Yalgorup Lakes and during low water levels in Lake McLarty.

 Phytoplankton – particularly significant in the Serpentine and Murray Rivers and in Goegrup lake and in the Peel Inlet and Harvey Estuary.

 Dissolved Oxygen - particularly in bottom waters and in the Serpentine and Murray Rivers.

 Salinity - particularly in the Yalgorup Lakes.

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 Littoral Vegetation – particularly along fringes of the Peel Inlet and Harvey Estuary and lower reaches of its tributaries.

The areas of most concern are the Serpentine River and Murray River where the greatest proportions of water samples exceed the LAC for total phosphorous and for dissolved oxygen and consequently where the greatest number of fish kills occur. The steady increase in salinity and nutrient concentrations in the Yalgorup Lakes is significant. In particular increasing salinity is likely to lead to the deterioration of the processes responsible for forming the Thrombolites if the trend is not able to be managed effectively.

Declining water quality in Lake Mealup (particularly pH) up to the construction of the Weir on the Mealup Main Drain and diversion of drainage water into the lake in 2012, appeared responsible for declining waterbird usage. However, since June 2012, water quality (with the exception of total phosphorous concentration) has improved and now close to natural conditions exist. It is hoped that as a result the lake will again support significant waterbird populations.

Similarly, the return to a more normal hydrological regime in Lake Mealup has led to significant regeneration of Paperbark in the littoral zone of the lake. Intensive management of the weed Typha (in Lake Mealup and Lake McLarty) has also improved habitat values of these lakes which is hoped will contribute to higher waterbird usage.

Evaluation of the available data for the biotic and abiotic components and processes for the Peel- Yalgorup System Ramsar site confirms that the attributes that justified its listing as a wetland of international significance in 1990 are still present in the system. However, significant pressures exist (including reduced rainfall and higher temperatures, together with future abstraction of groundwater and land use change) that have the potential to negatively impact on the ecological character of the wetlands that make up this system.

The current condition of the Peel-Yalgorup System Ramsar wetlands is discussed in detail Appendix D. Table 19-19 summarises the results of the condition assessment with reference to the LACs.

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Table 19-19: Summary of the condition against each of the LACs for the Peel Yalgorup System Ramsar site

Components and Limits of acceptable change (LAC) Condition Trend processes

Peel-Harvey Estuary

TP < 30 g/L (maximum). Poor Nutrients Stable to degrading PO4, NH4, NOx - median concentrations < 10 g/L Moderate to good

Dissolved Oxygen 70-80 % saturation Moderate to good Degrading pH pH > 7 at all times Good Stable

Winter salinity in the centre of the Peel Inlet and Harvey Estuary < 30 ppt for a minimum of 3 Salinity months. Moderate Degrading Water in the Harvey River mouth over winter < 3 ppt.

Chlorophyll a Median concentrations < 10 g/L Moderate Stable

Seagrass – LACs not established Benthic Plants NA NA Macroalgae – LACs not established

LACs not established for extent of samphire or paperbarks, but limited data suggests that Littoral vegetation any reduction in fringing vegetation will be significantly deleterious to the condition of the Moderate to good Degrading extent and condition system

Median CPUE for Blue Swimmer Crabs should not drop below 1.0 kg/trap lift per annum Estuarine invertebrates Moderate Stable (based on commercial fishing).

Fish LACs not established NA NA

Support > 20,000 total waterbirds in 4 out of 5 years

Waterbirds Support > 1 % of the population of the following birds 3 out of 5 years: (preliminary LACs that  Banded Stilt (3000) Moderate to good Stable to degrading need review)  Red-necked Stint (3200)

 Red-capped Plover (950)  Red-necked Avocet (1100)

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Components and Limits of acceptable change (LAC) Condition Trend processes  Fairy Tern (60)  Curlew Sandpiper (1800)  Sharp-tailed Sandpiper (1600)  Musk Duck (250)  Australasian Shoveller (120)  Eurasian Coot (10,000)  Grey Teal (20,000) Breeding recorded for waterbird species (Pelicans, Little Pied Cormorants, Little Black Cormorants, Black Swan, Grey Teal, Darter and Black-winged Stilt) a minimum of once No data available NA every three years.

Lakes McLarty and Mealup

PO4 < 30 g/L McLarty – degrading NH4 < 40 g/L Nutrients Moderate to good Mealup – Stable to NOx < 100 g/L improving All applied when water levels are > 500mm

Salinity under rush and sedge communities < 1 ppt. Salinity Good Stable to degrading Salinity under paperbark communities < 0.5 ppt. pH pH > 7 at all times Excellent Stable

Groundwater discharge LAC not established NA NA

Phytoplankton LAC not established NA NA

Aquatic Plants Greater than 50% of open water not covered in floating aquatic plants. Excellent Stable

Typha limited to < 20 % of the wetland area.

Littoral Vegetation Freshwater sedges covering a minimum of 20% of the wetland area. Good to excellent Stable

Paperbarks – no net loss in extent or health

Invertebrates LAC not established-surrogate indicator is maintenance of waterbird populations NA NA

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Components and Limits of acceptable change (LAC) Condition Trend processes

Support > 20,000 total waterbirds in 4 out of 5 years

Support > 1 % of the population of the following birds 3 out of 5 years:  Banded Stilt (3000)  Red-necked Stint (3200)  Red-capped Plover (950) Poor to good Insufficient information  Red-necked Avocet (1100)  Curlew Sandpiper (1800) Waterbirds  Black-winged Stilt (3000)  Sharp-tailed Sandpiper (1600)  Australasian Shelduck (2400)  Eurasian Coot (10,000) Breeding recorded for waterbird species (Australian Shelduck, Little Pied Cormorants, Little Black Cormorants, Black Swan, Grey Teal, Darter, Pacific Black Duck, Great Crested Grebe, No data available NA Purple Swamphen, Dusky Moorhen and Spotless Crake) a minimum of once every three years.

Yalgorup Lakes

Nutrients PO4, NH4, NOx - median concentrations < 10 g/L Moderate Degrading

Salinity Lake Clifton salinity < 35 ppt maximum and < 25 ppt during winter and spring. Poor Degrading pH pH > 7 at all times Excellent Stable

LAC not established, but limited depth to groundwater data suggests that hydraulic head has Groundwater discharge Moderate to good Stable to degrading reduced by between 20 – 50cm over the 20 year period since 1995

Phytoplankton LAC not established NA NA

Benthic Plants No sustained epiphytic macroalgal growth on Thrombolites at Lake Clifton Good Stable to degrading

Thrombolites No loss of Thrombolites at Lake Clifton Good Stable to degrading

Invertebrates LAC not established NA NA

Fish LAC not established NA NA

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Components and Limits of acceptable change (LAC) Condition Trend processes

Support > 1 % of the population of the following birds 3 out of 5 years:  Banded Stilt (3000) Waterbirds  Red-necked Stint (3200) Poor to good Stable to degrading (preliminary LACs that  Hooded Plover (950) need review)  Musk Duck (250)  Australian Shelduck (2400) Successful breeding recorded for waterbird species (Black Swans, Hooded Plover, Red- No data available NA capped Plover, Banded Lapwing and Great Crested Grebe).

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19.9.4 Conservation objective

The conservation objective for the Peel-Yalgorup Ramsar site is:

Maintain the ecological character of the Peel-Yalgorup Ramsar site via the ongoing presence of the following characteristics:

o Large and diverse complex of ecosystem types including shallow estuaries, coastal saline lakes and freshwater marshes.

o Populations of plants and animals important to maintaining the biodiversity of the Swan Coastal Plan bioregion, include threatened species and communities.

o An actively growing Thrombolite community.

o Water quality that is equivalent to or better than current and/or recent historical conditions.

o Suitable habitat to support a range of species during critical life cycle stages, including breeding and moulting waterbirds; over-wintering migratory shorebirds; and breeding fish and crustaceans.

o Very high abundance of waterbirds and migratory shorebirds, sufficient to meet Ramsar listing criteria.

o Breeding, nursery and feeding habitat for numerous fish and crustacean species.

19.9.5 Potential impacts from the classes of action

The following section discusses potential impacts to the Peel-Yalgorup Ramsar site from the proposed classes of action. It is important to note that while current pressures (‘legacy issues’) are discussed for context, the analysis of potential future impacts only relates to the classes of action.

The Ramsar site does not fall within the footprint of a proposed class of action and will therefore not be subject to direct impacts. However, there are a range of indirect impacts that are relevant including those relating to changes to groundwater and/or surface water (including nutrient inputs) and others associated with increased ‘people pressure’ to the site.

Impacts are assessed in accordance with the methodology described in Section 19.5 above.

Changes to ground water and/or surface water

Introduction

The potential impacts to groundwater and/or surface water are examined within the scope of proposed development including:

 infrastructure;

 planned future urban, industrial and rural residential land within the Peel-Harvey coastal catchment (including Peel-Harvey Estuary, Lake Mealup and Lake McLarty); and

 planned future rural residential land within the Yalgorup catchment.

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The total areas of existing and proposed urban, industrial and rural residential development within the relevant areas that inform the assessment are given in Table 19-20.

Table 19-20: Existing and proposed development areas in the Peel-Harvey and Yalgorup catchments

Peel-Harvey coastal catchment (ha) Urban Industrial Rural residential

Existing 14,004 3,840 7,906

Expansion 4,715 5,035 4,655

Future total 18,719 8,875 12,561

Yalgorup catchment (ha) Urban Industrial Rural residential

Existing 121 0 426

Expansion 0 0 31

Future total 121 0 457

The assessment of the changes to groundwater and/or surface water has been undertaken separately for the Peel-Harvey and the Yalgorup Lakes systems. This was considered appropriate due to both the different development pressures (as per Table 19-20 above) and different hydrological regimes of the two areas.

The Serpentine and Murray groundwater areas overlap the Peel-Harvey catchment. Lakes McLarty and Meelup are located within the Coolup subarea of the Murray Groundwater Area. Allocation limits for the Serpentine Groundwater Area only incorporate the volume for general licensing. Although there isn’t a groundwater allocation plan for the Serpentine Groundwater Area, allocation limits are set for the Superficial aquifer. A review of allocation limits in the groundwater area is planned for 2016-17.

The Yalgorup Lakes are located in the Peel Coastal Groundwater Allocation Plan area.

Current data on allocation limits, components and licensing from the Superficial aquifer within the Peel- Yalgorup Lakes catchment indicate there is water available for further general licencing within the Serpentine and Murray Groundwater Areas. Allocation limits within the South West Coastal Groundwater Area have been reduced to current use to protect the resource and its in-situ values. Groundwater level trends are relatively stable suggesting that discharge into wetlands has been maintained under current conditions, however there is concern that water quality changes may be occurring. This has been identified as a threat to the health of the Thrombolites as they rely on fresh groundwater discharge to maintain salinity levels below the limit of acceptable change at 35,000 ppt.

Current pressures – Peel-Harvey System

The major sources of water to the Peel-Harvey System are from direct rainfall, surface water flows (rivers and drains), groundwater and tidal exchange via the Dawesville Channel. The river inflows are from three major river systems, the Murray and Serpentine Rivers (which discharge to the Peel Inlet) and the Harvey River (which discharges to the Harvey Estuary).

Hydrological aspects such as rainfall, evaporation, river inflows and groundwater influences have not changed as a result of the Dawesville Channel. The Dawesville Channel, however, has had a significant effect on the tidal regime of the Peel Inlet and Harvey Estuary. An increase in tidal range has resulted in changes to the intertidal areas around the estuary. The intertidal zone is now broader than it was and

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upper intertidal areas are submerged more frequently but for a reduced duration, while lower areas are inundated less frequently for increased periods (DAL 2002).

One of the key changes in hydrology of the Peel-Harvey System relates to the recently drying climate in the south-west of Western Australia. During the last decade (2003-2013), this drying has resulted in total rainfall inflows into the Peel Inlet declining by 22% compared with the historical period at the time of Ramsar listing (1900-1990). Similarly, the inflows into the Harvey Estuary have declined by 18%. This is mostly due to declines in rainfall from February through to October.

The Peel-Harvey Estuary has suffered the effects of eutrophication for a number of decades. The construction of the Dawesville Channel was a component of a three part strategy to address the excessive nutrients entering the system. Although the nutrient concentrations within the estuary basins have decreased significantly since the opening of the Channel in 1994 due to increased tidal flushing, there is no evidence that there has been a corresponding reduction in nutrient loads entering the system from the catchment. To address the problem of eutrophication in the estuary, targets have been set for phosphorus and dissolved oxygen in the Water Quality Improvement Plan (EPA 2008a).

The median annual nutrient loads to the Peel-Harvey Estuary for the period 1997-2007 were estimated to be 1,022 tonnes of nitrogen and 140 tonnes of phosphorus (Kelsey et al. 2011). Of this, most originated in the coastal plain portion of the catchment, with 818 tonnes of nitrogen and 135 tonnes of phosphorus entering from a land area of 2,805 km2.

The areas of different land uses and their relative nitrogen and phosphorus loads are shown in Figure 19-6. The main sources of nutrient to the estuary are from septic tanks, horse and life style blocks, grazing, dairy farms, horticulture and intensive animal industries. As indicated in Figure 19-6, urban areas currently contribute a small amount of nutrient due to their small relative area. However since 2007, the urban area has increased. Work done since the modelling by Kelsey et al. has also shown that urban residential areas contribute similar or greater nutrient loads on a per area basis than most agricultural lands (Kelsey et al. 2010).

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Point Sources Septic tanks Horses & lifestyle blocks Grazing & cropping Cattle for dairy Conservation and natural Horticulture & viticulture Industry, manufacturing and transport Intensive animal use Urban Plantation

Figure 19-6: Relative land use areas and nitrogen and phosphorus loads flowing to the Peel-Harvey Estuary from the coastal plain portion of the catchment

Current pressures – Yalgorup Lakes

The Yalgorup Lakes primary inflows are direct rainfall and groundwater. Depth to groundwater measurements taken from a number of bores around the Yalgorup Lakes suggests that there has been a slight reduction in groundwater flows into the lake system over the last two decades. The reduction in groundwater depth together with reductions in direct rainfall onto the lake is reflected in a shallower lake depth in Lake Clifton as measured in early and late spring (September and November). The trend towards a shallower depth of around 0.5 m is reflected in data collected over a 27 year period from 1985 through 2012 (Lane et al. 2013).

The causes of reduced groundwater flows include reduced rainfall and increased evaporation across the catchment, land use changes, clearing and increased groundwater abstraction for private and commercial purposes, most notably the establishment of pine plantation near the site (Rockwater, 2009). Shams (1999) suggested that groundwater discharge rates to the Lakes were being affected by abstraction for horticultural, agricultural and rural residential purposes, however, the changes in volume have not been quantified.

Nutrients from the land uses adjacent to the Yalgorup Lakes are transported to the lakes in groundwater. Nutrient loads are thus difficult to estimate, as de-nitrification rates and potential to adsorb phosphorus to the soil matrix are unknown. Several authors (Gerritse et al. 2002) have highlighted the potential of sandy Swan Coastal Plain soils to become saturated with phosphorus within years or decades of fertilised land uses being established. Once this occurs, surplus phosphorus from fertilised land uses will quickly reach the lakes. Evidence suggested that the amount of nutrient entering Lake Clifton was critically high and the lake had exceeded its nutrient assimilation capacity in the 1990s (EPA

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1991). LACs for nutrients and pH are currently in moderate condition and appear to be on a degrading trajectory.

Future pressures and risks (broad scale)

The risk assessment work undertaken by the Department of Water has broadly identified future pressures and associated risks to ground and surface water resources within the Peel-Yalgorup Ramsar site. These are summarised in Table 19-21 and Table 19-22 and then further discussed below.

Table 19-21: Summary of groundwater risk assessment for the Peel-Harvey subarea of the Peel-Yalgorup Ramsar site

Potential impact Risk to quantity Risk to quality

Impacts from construction CLOSE to estuary or lakes – NA High temporary dewatering

Impacts from construction CLOSE to estuary or lakes – NA High temporary dewatering – activation of ASS

Impacts from construction CLOSE to estuary or lakes – NA Medium contamination

Impacts from construction AWAY FROM to estuary or lakes – Medium NA temporary dewatering

Impacts from construction AWAY FROM to estuary or lakes – NA High activation of ASS

Impacts from construction AWAY FROM to estuary or lakes – NA Medium contamination

Removal of vegetation and increased developed footprint High – contaminants NA (residential, industrial, rural residential) Very high – nutrients

Increased numbers of septic tanks or alternative units NA Very High

Farm dam construction Low NA

Alterations to drainage Low – medium Low – medium

Groundwater abstraction – non-potable supply Medium NA

Groundwater abstraction – potable (public water) supply Medium NA

NA – potentially NA – potentially Groundwater management activities beneficial OR medium beneficial

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Table 19-22: Summary of groundwater risk assessment for the Yalgorup Lakes subarea of the Peel- Yalgorup Ramsar site

Potential impact Risk to quantity Risk to quality

Impacts from construction – temporary dewatering Medium Medium

Impacts from construction – activation of ASS NA Medium

Impacts from construction – contamination NA Medium

Removal of vegetation and increased developed footprint NA Very high (rural residential)

Increased septic tank or alternative units NA Very High

Groundwater abstraction – supply for rural residential Very High Very High

In the Peel-Harvey subarea, the major risks are associated with nutrient and contaminant inputs to the system. High to very high risks to water quality (ground and surface) may result from construction activities, removal of vegetation and increased development footprint, and increased numbers of septic tanks or alternate treatment units (ATU’s). Risks to water quantity are considered lower due to the large volumes of water available to enter the system (ground, surface and tidal waters).

In the Yalgorup Lakes subarea, there are potential high risks to both the quantity and quality of water resources. Very high risks to groundwater quantity (and flow on impacts to Thrombolite communities) are associated with declining rainfall, increased evaporation, and abstraction for rural residential use. Landuse changes have the potential to reduce recharge or increase nutrient or other contaminants entering the system. Very high risks to water quality (ground and surface) may result from the increased rural residential footprint and an increased numbers of septic tanks or ATU’s.

Impacts from construction present a medium to high future risk to the Peel-Yalgorup System Ramsar site in both subareas. This is because:

 It is possible that dewatering during the construction phase of developments in the surrounding area could lead to reduced groundwater levels. Construction close to the Peel-Harvey Estuary presents a high risk, due to the potential for saltwater to intrude into dewatered areas.

 Digging, dewatering, drainage or abstraction activities in the wider area that lower the water table and expose sulfidic sediments has the potential to cause considerable environmental damage due to acidification. The impact on the Peel-Harvey Estuary may be less significant due to the influence of tidal flushing, though this depends on the extent of contamination.

 It is possible that construction activities may result in localised ground or surface water quality impacts. Contaminated groundwater could then discharge into the lakes or estuary and adversely affect the aquatic ecosystem health. The potential impacts on the lakes associated with contamination during the construction activities are considered major as once the Superficial aquifer has been contaminated, it can be very expensive and often impossible to remove the pollutant. Again, the impact on the Peel-Harvey Estuary may potentially be less significant due to the influence of tidal flushing, though this depends on the extent and type of contamination.

In the Peel-Harvey System, the expected magnitude of abstraction as a result of the relevant classes of action is difficult to estimate, but it is unlikely that licensed abstraction from the Superficial Aquifer will greatly increase (the South West Coastal management area is already fully allocated and others are

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likely to become so). The aquifer is too thin to support abstraction and is clayey and salty in many areas (Johnston pers. comm.). Thus, it is expected that future increased groundwater abstraction will have little impact on flow volume to the Estuary. Similarly, farm dam construction is also likely to be a small impact1. The future of aquifer recharge schemes in the catchment is unknown and thus difficult to risk assess. However, if and when such schemes occur any impacts will be fully assessed prior to establishment.

The Peel-Harvey Estuary currently receives approximately twice as much nitrogen and phosphorus as it can assimilate (Kelsey et al. 2011), thus any activities that increase the nutrient load into the system present a high to very high risk. In this assessment, the key high risk activities are the increased development footprint – particularly for residential and rural residential land uses, and an increase in the number of septic units and ATU’s (risk of leakage and/or overflow).

Recent improvement in technology such as reticulated sewerage, smaller lot size (and therefore gardens) and water sensitive urban design have the potential to significant reduce nutrient loads exported from urban developments. However, the efficacy of such technologies in WA is not well studied or understood. In contrast to eastern states, the sandy soils of south-western WA may limit the effectiveness of these technologies. Furthermore, ATUs should only be used in rural residential developments with sufficiently large lot sizes to minimise the risk of nutrient pollution to water bodies. At this time, there is a 1 ha minimum lot size specified under State Planning Policy 2.1 for the Peel-Harvey Coastal Plain Catchment (SPP 2.1), however some researchers suggest 2 ha may be more appropriate. Taking this uncertainty into account, the risk assessment has taken a worst-case scenario to future development with a resultant high to very high risk rating.

On sandy coastal plain soils such as those in the Perth Peel Region, most of the urban nutrients are applied in applications to gardens and lawns. These then infiltrate and drain to the artificial drainage network and are transmitted to receiving water bodies. Due to the limited ability of sandy soils to assimilate nutrients in the catchment, unless soil amendments are used in urban developments in the Peel-Harvey catchment, all intensification associated with residential development can be assumed to cause greater nutrient inputs than existing land uses. This assumption is further validated by unpublished data from the Department of Water, which suggests urban residential blocks larger than 400 m2 have some of the greatest nutrient application per hectare per year.

Future pressures and risks (specific expansion areas)

Using the methodology described in Section 19.5.4, Figure 19-7 shows the nutrient enrichment risk attributed to each of the proposed new urban, industrial and rural residential areas within the Yalgorup and Peel-Harvey coastal catchments. Locations that have a high risk are likely to require more management than low-risk areas. This risk rating should be considered in the context of the future proposed land use. Different land uses are associated with varying nutrient export risks owing to differences in nutrient inputs and transport pathways.

1 However, noting that localised impacts from the construction of dams on downstream wetlands can be significant and are likely to become more so with climate change. Off-stream farm dams are not regulated under the RIWI Act and therefore are the primary responsibility of local government regarding any approvals and management.

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As identified in the preceding section, urban areas can have some of the highest nutrient input rates per hectare. Of the proposed urban expansion, the North Ravenswood and West Pinjarra expansion areas represent the highest threat to water quality, given their relatively large size combined with high eutrophication risk. Development of these areas for urban land use represents a high risk to water quality and will require significant management and mitigation.

Nambeelup industrial expansion area also covers a large area and rates highly for eutrophication risk. With a proposed future industrial land use, the likelihood of high nutrient input rates is much lower than for urban areas (depending on the type of industrial activities allowed in the area). Export risk could be associated with either future point source discharges or with diffuse nutrient inputs if the area was not connected to the sewer. Due to costs of reticulated sewerage for large blocks, many industrial areas remain unsewered. In the case of Nambeelup, planning for this area is somewhat progressed and a Drainage and Water Management Strategy (DWMS) has been approved by the Department of Water. The DWMS and PRS amendment have confirmed the industrial area is to be connected to Water Corporation sewer services, and an Engineering Servicing Report has been provided to this effect. Any potential future point source discharges will be managed through DER licencing processes.

A number of rural residential areas also rate highly in terms of eutrophication risk, most sizable of which is North Dandalup. These areas will require careful consideration in relation to the use of septic tanks and ATUs.

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Figure 19-7: Phosphorus Risk for Urban, Industrial and Rural Residential Expansion areas within 5km of the Becher Point Wetlands

Legend Urban Strategic Assessment Area Becher Point Wetlands 5km Buffer Phosphorus Risk 0-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10

Rural Residential

0 2.5 5

Kilometres Datum/Projection: GDA 1994 MGA Zone 50 Data Source: DoW (2015) Prepared by: SM Date: 19/11/2015 ± Strategic Assessment for the Perth and Peel Regions

Increasing people pressures

Current pressures

For decades, the Peel-Harvey Estuary and surrounds have been an important recreation destination for tourists and local residents. Land and water-based recreation and tourism form an integral part of the Peel Region. Tourism and recreation are a strong focus in the Peel region, and it is estimated that tourism brings in approximately $150 million dollars per annum (URS 2007). The increase in residential development and the opening of the Forest Highway has increased recreational pressure on the Peel- Yalgorup site.

The lands and waters of the Ramsar site include a number of popular day use and recreation destinations. Popular recreational activities include bushwalking, bird watching, picnicking on lands around the estuary, camping, horse-riding, motorbike and four-wheel-driving, fishing, swimming, boating, crabbing, water skiing, jet skiing and canoeing.

The Peel-Yalgorup estuarine and river waterways provide one of the most popular recreational boating and fishing environments in WA. The more sheltered estuary and river environments provide conditions suitable for boating over longer periods than more exposed ocean environments. The Peel Region Recreational Boating Facilities Study (Department of Transport, April 2011), which covered the City of Mandurah and the Shires of Murray and Waroona, identified that:

The Department of Transport conducts surveys of boating activity at boat launching facilities located in the Peel Region. Results from a survey undertaken from December 2008 to January 2009 to identify postcode distributions of boats using the Peel estuary found that boat users were prepared to travel from Perth and outskirts and from the southwest of the State (such as Collie and Harvey) to undertake boating activities in the Peel Region waterways.

While recreational enjoyment of the Peel-Yalgorup site is a service/benefit of the wetlands, it also has the ability to impact negatively on the ecological character. The two major impacts are erosion and physical disturbance of the shoreline and adjacent fringing vegetation due to boating and recreational vehicle use, and disturbance of waterbirds at vulnerable stages in their lifecycle.

Future pressures and risks

The risk assessment work undertaken by Parks and Wildlife has identified future ‘people pressures’ and the associated level of risk to ecological values at the Peel-Yalgorup Ramsar site. These are summarised in Table 19-23 and then further discussed below.

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Table 19-23: Summary of people pressure risk assessment for Peel-Yalgorup Ramsar site

Risk to Potential impact Risk to littoral and/or aquatic ecosystems shorebirds

Access (unlawful) – vehicles, unpowered High – physical disturbance; weeds & Medium vessel launching, camping dieback

Access (lawful) – vehicles, unpowered Medium – physical disturbance; weeds & Medium vessel launching, camping dieback

Access (lawful) – pedestrians (incl. dog High – physical disturbance High walking) Medium – weeds & dieback

High – physical disturbance to vegetation; Boating incl. boats, jet skis, fan boat Medium foreshore erosion

Bird watching NA Medium

Recreational fishing (incl. crabbing and High – physical disturbance; unsustainable Medium prawning) catch

Increased infrastructure for recreation – High – physical disturbance; erosion Medium launch sites and moorings

Fire – arson and campfire escapes High – physical disturbance; death NA

Increased number of dogs and cats from NA High residential areas

Trampling and interference with High – physical disturbance NA Thrombolites (pedestrian and vehicle)

Overall, the majority of recreational activities undertaken in the Peel-Harvey Ramsar site present a high future risk to littoral and/or aquatic ecosystems. Of these, activities which involve dogs (or cats) also present a high risk to shorebirds.

Access and recreational use are already impacting on the ecological character of the Peel-Yalgorup Ramsar site. This situation is likely to be exacerbated in the future, with considerable potential impacts, unless appropriate measures can be put in place to adequately manage the future pressure.

Access (both lawful and unlawful) to terrestrial areas of the site has the potential to damage littoral vegetation both directly (e.g. via trampling) and indirectly via the introduction of weeds and dieback. In particular, claypans surrounding the Peel-Harvey Estuary are favoured locations for illegal four-wheel driving, motor cycles and quad bikes, while the Thrombolite communities of Lake Clifton have experienced trampling and physical disturbance. With more people living around and visiting the Peel- Yalgorup Ramsar site, there is likely to be an increase in this type of activity.

Boating activities have the potential to impact both terrestrial vegetation during launching and aquatic communities during on-water boat use. The Economic Development and Recreation Management Plan for the Peel Waterways (ECB & WRC 2002) identified erosion of foreshores in the estuary from boat

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wash as a major threat to the fringing vegetation. This trend is likely to continue with increases in boating numbers from both the local and regional population.

With an increase in population, the recreational areas will experience heavier use on a more frequent basis, resulting in the need for further recreational infrastructure (i.e. boating launch sites and moorings). The future construction and installation of these sites could result in disturbance to animals and habitat if installed inappropriately or in an unsuitable location. Subsequent use of these facilities, or increased use of existing facilities, may also result in ongoing risk of physical disturbance and erosion around the Peel-Harvey Estuary.

Fire (from arson and campfire escapes) presents a high risk to the littoral vegetation and the predicted frequency of arson is expected to increase with greater usage of the site and surrounding urban populations. Damage and death of vegetation is a direct result of fire and can favour the introduction of exotic flora species.

The Peel-Harvey Estuary is recognised as one of the most important shorebird sites in south-western WA. The majority of activities likely to increase into the future have been assessed as presenting a medium risk to shorebirds, with those associated with dogs and/or cats a high risk. Given the importance of this site to shorebirds, and current evidence from the LACs that shorebird numbers may be declining, it is deemed critically important that all management measures put in place to address recreational pressures to the Ramsar site consider shorebirds and take proactive steps to reduce disturbance both directly to the birds and indirectly to their habitats.

19.9.6 Mitigation and management

As outlined in the previous sections, the current condition of the Ramsar site is the subject of a range of historical and current pressures. These ‘legacy issues’ are the dominant factors in the health of the system and at a high level include:

 Decreasing inflows to the wetlands – due to a number of factors including decreased rainfall, increased evaporation, groundwater abstraction, and land use change.

 Increasing people pressures – due to a range of activities associated with the existing population.  Altered tidal regime in the Peel inlet – due to the construction of the Dawesville channel.

 Decreasing inflows to the Yalgorup lakes – due to potential groundwater abstraction from rural residential development.

 Increasing people pressures - due to a range of activities associated with the growing population.

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The Strategic Conservation Plan (and supporting action plans) provides a package of commitments to address both the legacy issues and future risks from the classes of action. It does this through:

 A set of State commitments in Action Plan G to address the legacy issues.  A set of MNES commitments in Action Plan F to address the risks from the classes of actions.

The framework for this package of commitments is illustrated in Figure 19-8 and discussed below in relation to:

 water quality;

 continued management of groundwater resources;  people pressures;

 monitoring and indicators; and

 implementation and policy.

The conservation commitments are identified in the text and provided in full at the end of this section.

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Figure 19-8: Framework for State and MNES commitments for the Peel-Yalgorup Ramsar site

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Water quality

Current and future pressure to water quality will be addressed through a wide ranging set of measures that are encapsulated in two key commitments:

 implementation of actions to improve and maintain the health of the Peel-Yalgorup wetland system, particularly through the reduced inflow of nutrients (State commitment #37); and

 specific consideration of two proposed urban expansion areas to address potential water quality impacts (MNES commitment #99).

Reducing the inflow of nutrients

There are three key measures to reduce the inflow of nutrients:

 targeted mandatory soil testing on the coastal plain;

 long term drainage intervention program for the Peel-Harvey Catchment; and

 promotion of the use of soil products.

Targeted mandatory soil testing on the coastal plain

Reducing the over-application of agricultural fertiliser is thought to be the most cost effective long term intervention to prevent further deterioration of both the Peel-Harvey and Swan Canning Estuaries (while the Swan Canning is not directly related to the Peel-Harvey Estuary it is discussed here given the overlap in the program).

Agriculture in the coastal plain catchments contributes approximately 80% of the total phosphorus inflows into the Peel-Harvey Estuary and one-third of the total phosphorus inflows into the Swan Canning Estuary.

Available research suggests that due to historic fertiliser application approximately 70% of paddocks in the Peel-Harvey coastal catchment do not currently require additional phosphorus application to maintain farm productivity. From the sampling of properties undertaken as part of the Fertiliser Partnership arrangements even greater over application of phosphorus is evident in the Swan Canning coastal catchment. The research suggests that if phosphorus was applied based on soil testing calibrated for local soil types then phosphorus losses from agriculture in these coastal plain catchments could be reduced by 25%.

The proposed program aims to reduce the over application of fertilisers at targeted sites in the Peel- Harvey and Swan Canning coastal catchments as well as improve soil productivity, agronomic yield and economic outcomes for agricultural fertiliser users.

The proposed program would apply to properties over 40 hectares in the Peel-Harvey and Swan Canning coastal plain catchments where the land is used for commercial agricultural production and consist of two parts:

 soil testing and agronomic advice and reporting; and  a targeted extension program.

Landholders covered by the regulations will be required to undertake and submit a valid soil test at least once every three years and receive independent agronomic advice prior to the application of fertiliser.

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The proposed regulation leaves the ultimate decision regarding fertiliser application with the landholder (i.e. it is not proposed to regulate fertiliser use).

The program will capture approximately 800 properties in Peel-Harvey and a further 200 properties in the Swan Canning coastal catchment. It is proposed that the State meet the costs of the soil testing and independent agronomic advice for the first three years of the program estimated at $6 million with detailed costings to be finalised as part of the 2016 State budget process.

Drainage intervention

The extensive engineered drainage system on the Peel-Harvey coastal plain carries the bulk of the nutrient run-off from agricultural land uses to the rivers and estuaries in the Peel Region. While there has been some progress in constructing interventions to remove nutrients from the Swan Canning drainage system there has only been very limited work of this nature to date in the Peel-Harvey coast catchment.

In order to meet the phosphorus inflow target for the Peel-Harvey it is necessary to achieve a further reduction of 30-35 tonnes/year of phosphorus inflow on top of the reductions that are projected to be achieved through the targeted mandatory soil testing program. In the absence of other alternatives that can be effective on this scale, it is proposed to implement a drainage intervention program to deliver this reduction.

Based on work undertaken by the Department of Water, Peel-Harvey Catchment Council and the Department of Premier and Cabinet, in liaison with Water Corporation and Parks and Wildlife, it is estimated that a drainage program to reduce phosphorus inputs to the estuary from drains by 30-35 tonnes/year would cost approximately $110 million over 20 years.

The key components of this program are summarised as follows:

 constructed wetlands augmented with offline treatment technologies;

 stock exclusion and riparian zone management;  application of phosphorus binding clays or equivalents;

 sedimentation basins for organic carbon removal;

 drain maintenance;  drain modification at subcatchment and landholder scale; and

 urban stormwater retrofitting.

This program would build on the five drainage intervention projects (totalling $3.85 million) targeting the reduction of phosphorus, sediment and organic matter in the Peel-Harvey Catchment that have been developed and submitted to Royalties for Regions for funding as part of a broader Regional Estuaries Initiative. Elements of the long term program could commence immediately following completion of the strategic assessment process, based on an expansion of work undertaken with the proposed Royalties for Regions funding. However, for other components of the program further work will need to be undertaken on tenure, design and risk issues (e.g. hydraulic and flood modelling).

The long term program would be split into 3 stages:

 design and establish pilot projects for rural drainage interventions and complete urban stormwater retrofits (over five years);

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 implement proven designs for rural drainage interventions in priority sub catchments over 10 years); and

 evaluation and refinement of projects and ongoing management arrangements (over five years).

The first five years of the program are proposed to allow refinement of the most promising nutrient capture techniques and to evaluate efficacy of the various options. Substantial community consultation and site identification would allow land access (both public and private) to be resolved for the second phase.

Many of the interventions would be similar in concept to the Wetland Treatment System, which has been constructed at the lower end of Ellenbrook to reduce nutrient inflows from agriculture into the Swan River, with early results showing a high degree of effectiveness.

Promotion of the use of soil products

Western Australia’s sandy soils are characterised by low natural fertility, poor water-holding capacity, poor nutrient retention and a tendency to become water-repellent. The greater demands on these soils to sustain consumers have required regular inputs of nutrients and high quality water. In most cases, the required nutrients are applied in the form of water-soluble chemical fertilisers. This practice is not environmentally sustainable and has been identified as one of the major contributors to algal pollution problems in the Perth and Peel rivers and estuaries.

The addition of appropriate natural (compost and clay) and/or recycled (soil products) materials to soils has the potential to improve water and fertiliser selection and efficiency, while having no detrimental impact on production quantity or quality.

One of the current barriers to this process is uncertainty about which soil products can safely be used. Soil products are waste derived materials that have been evaluated in such a way that their use will not cause unacceptable risk to the environment. Although there is considerable interest in the use of soil products, until recently there have been inadequate regulated standards to identify the beneficial constituents and potential contaminants in order to understand the application risks.

To address this, State agencies are actively progressing steps to progress a regulatory system for the use of Waste Derived Material to land, providing the materials used do not compromise environmental values. The intention is that materials that meet the standard will be classified as a 'soil product' in the first instance. The next phase will focus on doing further work on matching the soil product type and application rate to the characteristics of specific soil types.

Investigations of proposed urban expansion areas

As identified previously, the proposed North Ravenswood and West Pinjarra expansion areas represent a risk to water quality in the Peel-Harvey Catchment, given their relatively large size combined with high eutrophication risk.

Any future development within these areas will require specific consideration of water quality issues in accordance with the Better Urban Water Management Framework.

Continued management of groundwater resources

Current and future pressures to groundwater will be addressed through continued management of groundwater resources in accordance with the requirements of existing legislation and policy (MNES commitment #98). This is particularly relevant to the Yalgorup lakes. 19-87

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Due to climate induced reductions in recharge it is unlikely that there are sufficient groundwater resources to meet future demand. The development of alternative water source options will be required. There is also a need to implement several management strategies as part of conducting the current review of the Peel Coastal Groundwater Allocation Plan to minimise the impacts of a drying climate and abstraction upon the Yalgorup Lakes system. Proposed strategies include:

 Groundwater Dependent Ecosystem (GDE) licence assessment tools to minimise the risk of proposed abstraction near GDEs including the Thrombolite Threatened Ecological Community (TEC) and wetland habitat of migratory and threatened bird species.

 Minimising further risks to GDEs by reducing allocation limits to restrict the availability of additional groundwater licences.

 Monitoring and evaluation of prescribed GDE sites against resource objectives. These sites need prescribed minimum groundwater levels and salinity profiling to inform reporting and evaluation of resource objectives.

 Interventions to safeguard the EPBC Act listed Thrombolite TEC from the impacts of increased groundwater abstraction.

 Managed aquifer recharge where feasible as an alternative source in urban areas to offset reduction of groundwater inflow.

The review of the Southwest Coastal Groundwater Allocation Plan led to the new Peel Coastal Groundwater Allocation Plan being released for public comment in November 2014 and has the following objectives:

 prevent significant inland movement of seawater due to abstraction;

 prevent salt water up-coning affecting other users;

 maintain groundwater levels in the superficial aquifer that minimise risk to groundwater-dependent ecosystems; and

 maintain sufficient fresh groundwater discharge into Lake Clifton, Lake Preston and Martin’s Tank.

This is to be achieved using the following management measures:

 Reducing allocation limits by up to 50 per cent, and capping at current levels of use.

 Increased monitoring and reporting requirements for water user under operating strategies. This will allow agencies to monitor the impact to the resource that individual abstraction is having and help determine the level of risk associated with the abstractions.

 Recommencement of water quality profile monitoring to identify changes to the thickness of the freshwater lens in response to groundwater abstraction and climate change.

 Implement groundwater triggers which relate groundwater level to groundwater discharge into Lake Clifton, Lake Preston and Martins Tank to identify if groundwater levels decline may impact on discharge into lakes.

Despite these management strategies, it should be noted that climate change has the potential to reduce direct and indirect inputs into the lakes. Additional management options that may need to be considered in the future include:

 Remove pine plantations: reduce evapotranspiration and interception of groundwater to increase discharge into wetlands.

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 Water reuse – reduce abstraction to increase discharge into wetlands.

 Water trading – optimise water use.  Restricted abstraction within wetlands buffers.

 Direct supplementation into Lake Clifton.

Construction

Examples of such controls include:

 Construction Environment Management Plans (CEMPs);

 Acid Sulfate Soil Management Plans;  Sediment and Erosion Control Plan;

 spill response procedures; and

 appropriate storage and stockpiling of oils, greases, heavy metals and other potential contaminants.

Better Urban Water Management Framework

People pressures

Current and future pressure to the Ramsar site from people will be addressed through two key measures:

 establishment and management of the Peel Regional Park (MNES commitment #95); and

 expansion of the Yalgorup National Park (MNES commitment #97).

Establishment and management of the Peel Regional Park

The key commitment to manage recreational pressures and achieve positive biodiversity (and therefore Ramsar) outcomes is the establishment of the Peel Regional Park. Action Plan H of the Strategic Conservation Plan incorporates details about this process and describes the new park as follows:

“The Peel Regional Park comprises the Peel Inlet, Harvey Estuary and the lower parts of the associated rivers (Murray, Serpentine and Harvey) together with 6,375 hectares of land surrounding these waterways.”

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Regional parks are areas identified as having regionally significant conservation, landscape and recreation values and may consist of land areas managed by a range of different land management agencies, and private landowners. Regional parks therefore provide the opportunity for a consortium of land managers and landowners to work together to develop a coordinated management approach.

The park will provide for coordinated management of land and waters for conservation and recreation across a range of tenures and represents an important biodiversity conservation action to directly benefit the Ramsar site, including:

 more effective management of impacts on Ramsar values from threatening processes resulting from increased population pressures and recreational activity;

 coordinated management of the park between State Government agencies and local government leading to significant efficiencies in management of waterway and foreshore issues;

 delivery of biodiversity conservation initiatives whilst enhancing community use and provision of nature based tourism and recreation opportunities;

 protection of important landscapes of the Peel Region;

 protection and sustainable management of the Peel Inlet and Harvey Estuary, which is the largest commercial and recreational estuarine fishery in Western Australia;

 protection of indigenous and non-indigenous cultural heritage sites; and

 raising awareness and engaging the community in local conservation issues.

The creation and management of the park will also assist with delivering regional scale conservation outcomes and deliver unfulfilled objectives of the Environmental Protection Authority’s (EPA) Environmental Protection (Peel Inlet-Harvey Estuary) Policy 1992, recommendations of the EPA on the PRS (Bulletin 994, August 2000) and the EPA’s Peel Inlet and Harvey Estuary System Management Strategy (Bulletin 1087, January 2003).

Establishment will include the following priority conservation projects which are proposed to be funded as up-front conservation actions:

 The Peel-Yalgorup Ramsar site boundary extension – to include the Serpentine River and associated wetlands of Goegrup and Black lakes. This will help improve alignment between the Peel Regional Park and the Peel Yalgorup Ramsar site boundary.

 Acquisition of privately owned land reserved for Regional Open Space for inclusion in the conservation reserve system.

 Peel-Harvey Riparian Zone Restoration Project – to work with the Peel-Harvey Catchment Council and other stakeholders to conserve remnant and riparian vegetation and restore disturbed areas (i.e. control of off-road vehicles, feral animals, weeds and dieback, and undertake revegetation, rehabilitation and restoration projects).

 Access to the Estuary Strategy – to work with the community and other stakeholders to implement multi-use recreational nodes and a network of trails, primarily for walking, cycling and canoeing which link recreation sites and other destinations around the Peel-Harvey estuary and associated waterways. The strategy would deliver upgrades to day use recreation sites such as picnic areas, canoe and boat launching areas that ensure recreation occurs in a controlled and planned manner utilising appropriate areas thereby taking pressure off sensitive conservation sites and values.

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 Migratory Bird Habitat Protection Works – to protect and restore estuarine ecosystems and Ramsar values focussing on priority areas for migratory birds and shorebirds. This would comprise habitat protection, interpretation, on-ground management and monitoring. As part of this priority conservation program it is proposed to expand Len Howard Conservation Park and Class A nature reserves at Samphire Cove, Creery, Austin Bay and Kooljerrenup into the adjacent intertidal areas. Within these reserve expansion areas added protection would be provided to migratory shorebird habitat and disturbance to birds from pedestrians, dogs and cats, motorised and non-motorised vessels would be better managed. Access would also be limited during critical feeding and breeding times (November to March). There would be no proposed restriction on fishing within these areas. The management of fishing would remain the responsibility of the Department of Fisheries as per current management arrangements.

It is proposed that Parks and Wildlife will coordinate management of the Peel Regional Park according to a management plan prepared in consultation with stakeholders under the Conservation and Land Management Act 1984. The management plan will provide the statutory framework for management of those lands and waters within the regional park vested in the Conservation Commission and Marine Parks and Reserves Authority, and also provide direction for other agencies in managing their lands in the park.

The park will be managed for conservation and recreation purposes across a range of different tenures. Parks and Wildlife’s role in the park will encompass, but may not be limited to:

 managing lands owned by the Western Australian Planning Commission prior to them being transferred to the Conservation Commission of Western Australia;

 managing lands vested in the Conservation Commission of Western Australia;

 managing waters vested in the Marine Parks and Reserves Authority; and  preparing a Peel Regional Park management plan ensuring an integrated management approach between the management of land, water and the different management agencies involved in the park.

The management planning process will be coordinated by Parks and Wildlife, in liaison with the relevant local governments and the community. The regional park will have a formal management advisory committee drawing members from local government, Aboriginal, conservation, recreation and tourism stakeholder groups. The committee will be convened and administered by Parks and Wildlife. This follows the model implemented for existing regional parks.

Further consultation on park management issues including final park boundaries and a new park name will occur during the management planning process for the park.

Funds will be made available to Western Australian Planning Commission/Department of Planning for the acquisition of additional private property currently zoned as Regional Open Space for inclusion into the conservation reserve system. Ongoing recurrent funding will be allocated to Parks and Wildlife for the ongoing management of the park. Protecting the biodiversity values of the park by conserving remnant vegetation and restoring disturbed areas will be a key outcome and will be undertaken in conjunction with the local community. Funding will be available for implementing strategies for collaborative management of recreational access and associated impacts to fringing vegetation and the control of feral animals, weeds and dieback.

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Expansion of the Yalgorup National Park

Specific to the Yalgorup portion of the Ramsar site is a commitment to expand Yalgorup National Park south to Binningup along the coast. This would include land acquisition and maintenance of values. Components include:

 Cape Bouvard freehold lands (approximately 1,180 ha);

 land for conservation, ecosystem linkages and Ramsar buffer – acquire private land for southern extension (approximately 2,333 ha); and

 State forest converted to national park. (approximately 2,050 ha).

Monitoring and indicators

A program of water quality monitoring for the Peel-Harvey catchment will be established as part of the over-arching assurance processes for the Strategic Conservation Plan. These measures are incorporated into Action Plan I.

The monitoring program (MNES commitment #96) will incorporate a specific focus on the LACs to ensure that conditions and trends in the wetland system are understood, and so that management can be focused on ensuring the ecological character of the site is maintained.

The State will also under take a range of activities to improve the knowledge and understanding of the water quality of the Peel-Harvey catchment (State commitment #39). These will be focused on supporting decision making and include:

 developing estuarine health indicators; and

 setting water quality objectives for all sub-catchments.

Implementation and policy

Effective implementation of the conservation commitments for the Peel-Yalgorup Ramsar site over the life of the Strategic Conservation Plan will be critical. In particular, the implementation arrangements of the State commitments to improving water quality will be improved.

In addition, review of relevant State policies will be undertaken (State commitment #42).

Implementation of water quality commitments

It has been recognised for some time that a number of agencies and community groups are involved in the delivery of activities related to water quality and land use planning in the Peel-Harvey and that improved coordination of effort could yield better results.

In the short term, the existing statutory Peel Regional Planning Committee (PRPC) is proposed to be reconstituted to ensure that planning decisions are cognisant of the water quality improvement outcomes associated with the approved classes of action. This will be a fundamental undertaking to ensure that the statutory planning system gives effect to the approved strategic objectives.

A non-statutory arrangement has been established as an interim measure to deliver on an election commitment and to lead and coordinate the development of relevant Peel-Harvey components of this project and implementation of the measures described above. The Peel-Harvey Estuary Management Committee (PHEMC) comprises Director General level officers (or equivalent) of the key agencies and 19-92

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NGO’s involved in decision making and on-ground delivery of activities and projects that aim to improve water quality. The establishment of this arrangement now will help immediately reduce duplication, coordinate existing management effort and inform the preparation, implementation and reporting of the State’s future management commitments for the system. The committee’s work is supported by a Senior Officers Group (SOG) drawn from the key agencies with secretarial support from Department of Premier and Cabinet.

In the longer-term, the Peel-Harvey Estuary Management Committee will transition to a different administrative arrangement, namely a non-statutory management committee, the Water Quality Taskforce (State commitment #38). This committee would report to the Minister for Water, and implement the relevant parts of the Strategic Conservation Plan with a focus on water quality improvement in the Peel-Harvey Estuary (State commitment #37) in order to:

 Oversee the delivery of the mandatory soil testing and independent agronomic advice and related behaviour change and extension program.

 Facilitate the availability of soil amendments and uptake.

 Reduce the volume of nutrients leaving the drainage system.

 Build partnerships and educate community to support delivery of above objectives.  Monitor implementation and effectiveness of existing development control mechanisms in the context of supporting WQIP targets and other Ramsar commitments, and provide advice on reform over time.

 Reduce soil erosion, organic loading and other nutrient runoff in the catchment through riparian zone and wetland management and protection, in partnership with landholders, local government and government agencies.

 Monitor and report on progress against water quality targets.

Policy review

State Government agencies have been investigating means across Government to regulate land use, and environmental protection in the Peel-Harvey Catchment, to achieve the water quality targets set out in the Peel-Harvey Water Quality Improvement Plan (WQIP).

The State Planning Policy 2.1 for the Peel-Harvey Coastal Plain Catchment (SPP 2.1) and the Environmental Protection Peel Inlet – Harvey Estuary Policy 1992 (EPP) provide environmental quality objectives (through the EPP) and a mechanism for achieving and maintaining these objectives (through the SPP 2.1). Limited implementation of the policies set out in SPP 2.1 and the EPP and the management measures recommended in the WQIP and the lack of a strong and cohesive governance body to oversee progress towards water quality targets has resulted in little change to the rate of phosphorus inputs to the Peel-Harvey catchment in the last 20 years.

Revision of SPP 2.1 and the EPP will occur (State commitment #42) with a key focus on preventing high nutrient export activities on soils with a low phosphorus retention capacity. To support this as part of the same commitment the State will also consider the development of Planning and Development Act 2005 mechanisms.

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Conservation commitments

The package of conservation commitments for the Peel-Yalgorup Ramsar site are provided in Table 19-24. This includes the State commitments (Action Plan G) to address legacy issues and MNES commitments to address future risks from the classes of action (Action Plan F).

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Table 19-24: Package of commitments to address both the legacy issues and future risks from the classes of action

State commitments to address legacy issues (Action Plan G) MNES commitments to address future risks of the classes of action (Action Plan F)

State commitment #37  Establish the proposed Peel Regional Park and marine management area (as  Implement key actions necessary to improve and maintain the health of the Peel- detailed in Action Plan H) including the following priority conservation projects: Yalgorup wetland system, particularly through the reduced inflow of nutrients, using o Peel Yalgorup Ramsar site boundary extension; a whole of catchment management approach, including: o acquisition of regional open space land for inclusion in the conservation o Implementing mandatory best practice soil testing. reserve system; o Reporting fertiliser use. o Peel-Harvey Riparian Zone Restoration Project; o Facilitating the greater uptake of soil products to reduce nutrient runoff and o Access to the Estuary strategy; and leaching, and improve water holding capacity on poor soils. o Migratory Bird Habitat Protection works (including expansion of existing nature o Instigation of a drainage intervention program. reserves and conservation park into intertidal areas). o Continuing bagged fertiliser regulation. o Development of nitrogen targets and to guide catchment management  Implement a monitoring program that includes the limits of acceptable change. decisions. o Development of actions to reduce sediment and organic loading.

o Improvement in the monitoring and reporting on the health of the river system  Extend the Yalgorup National Park (as detailed in Action Plan H). including the publication of annual water quality report cards. o Improve regulation of agricultural point sources.

o Undertaking of whole of catchment numerical modelling to provide revised load  Continue to manage groundwater resources in accordance with the requirements reduction targets that will support drainage management actions, guide of existing legislation and policy including taking an adaptive management investment planning and provide the basis for compliance testing against approach to groundwater allocations based on annual evaluations. targets, with modelling to be reviewed every five years

o Development, operation and maintenance of an estuarine ecosystem response

model to inform management decisions

State commitment #38  Any future development within the Ravenswood North or Pinjarra West precincts  Establish the Peel-Harvey Water Quality taskforce as a coordinating body to will require specific consideration of arising water quality issues. These precincts 19-95

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State commitments to address legacy issues (Action Plan G) MNES commitments to address future risks of the classes of action (Action Plan F) oversee roles, responsibilities and actions relating to protection of the are located in environmentally sensitive hydrological catchments and may require environmental values of the Peel-Harvey system. additional design measures to address water quality and quantity. Such measures should be identified as early in the land use planning process as possible, in State commitment #39 accordance with the Better Urban Water Management Framework.  Undertake activities that improve the knowledge and understanding of the water quality of the Peel-Harvey and Swan-Canning catchments to support decision making including: o developing estuarine health indicators; and  Additional commitments related to the Thrombolite (microbialite) Community of a Coastal Brackish Lake (Lake Clifton) are incorporated into Action Plan F o setting water quality objectives for all sub-catchments.

State commitment #42  Review the State Planning Policy 2.1 for the Peel-Harvey Coastal Plain Catchment (SPP 2.1) and the Environmental Protection (Peel-Harvey Estuary) Policy and consider development of Planning and Development Act 2005 mechanisms to prevent high nutrient export activities on soils with a low phosphorus retention capacity.

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19.9.7 Outcome for the Peel-Yalgorup Ramsar site

The assessment has identified that the major issues facing the condition of the Peel-Yalgorup Ramsar site relate to a range of historical and current pressures ('legacy' issues). However, potential indirect impacts from the classes of action pose a series of risks that need to be managed appropriately.

Legacy issues

The legacy issues which are the dominant factors in the health of the system include:

 Decreasing inflows to the wetlands – due to a number of factors including decreased rainfall, increased evaporation, groundwater abstraction, and land use change.

 Increasing people pressures – due to a range of activities associated with the existing population.

 Altered tidal regime in the Peel inlet – due to the construction of the Dawesville channel.

It is critical that these issues are addressed in order to maintain the ecological character of the wetlands. As a result, the State is providing a series of commitments through Action Plan G (State commitments) which include:

 Actions to improve the health of the Ramsar site including improving water quality. These include mandatory best practice soil testing, drainage interventions, and promoting the use of soil products.

 Establishment of the Peel-Harvey Water Quality task force which will be a coordinating body to oversee roles, responsibilities and actions relating to protection of the environmental values of the Peel-Harvey system.

 Improving knowledge and understanding of water quality of the Peel-Harvey catchment. This will provide a better understanding of the ecological responses to water quality in order to inform adaptive management of the system.

 Review of the State Planning Policy 2.1 for the Peel-Harvey Coastal Plain Catchment (SPP 2.1) and the Environmental Protection (Peel-Harvey Estuary) Policy with the aim of preventing high nutrient export activities on soils with a low phosphorus retention capacity.

Classes of action

While there will be no direct impacts to the Ramsar site as a result of the classes of action, there are a set of future indirect pressures and risks. These are considered to be of a lower magnitude than the catchment scale legacy issues, but it is critical that they are mitigated and managed appropriately.

The potential indirect impacts include:

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 Decreasing inflows to the Yalgorup lakes – due to potential groundwater abstraction from rural residential development.

 Increasing people pressures - due to a range of activities associated with the growing population.

As a result, the State is providing a series of commitments through Action Plan F (MNES commitments) which include:

 Establishing the Peel Regional Park and expand Yalgorup National Park to provide for improved protection and management of the Ramsar site.

 Continuing to manage groundwater resources in accordance with the requirements of existing legislation and policy with the aim of avoiding over abstraction of groundwater.

 Addressing potential water quality impacts from the proposed Ravenswood (north) and West Pinjarra urban expansion areas.

 Implementing a monitoring program that includes the limits of acceptable change to better understand and manage the Ramsar site.

Outcome

Based on the package of commitments to address both the legacy issues and future risks from the classes of action, it is expected that the conservation objective for the Peel-Yalgorup Ramsar site will be achieved.

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