An across-government initiative
groundwater – biodiversity – land use
July 2009 Gnangara sustainability strategy appendix 1 Gnangara groundwater system zone plans Draft for public comment
An across-government initiative
Department of Water Department of Agriculture and Food WA Department for Planning and Infrastructure Department of Environment and Conservation Gnangara sustainability strategy task force Department of Water 168 St Georges Terrace Perth Western Australia 6000 Telephone +61 8 6364 7600 Facsimile +61 8 6364 7601 www.gnangara.water.wa.gov.au
© Government of Western Australia 2009
July 2009 This work is copyright. You may download, display, print and reproduce this material in unaltered form only (retaining this notice) for your personal, non-commercial use or use within your organisation. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. Requests and inquiries concerning reproduction and rights should be addressed to the Department of Water.
All maps in this publication were produced by the Department of Water (for the GSS Taskforce), with the intent that they be used for the Gnangara sustainability strategy (draft for public comment). While the Department of Water has made all reasonable efforts to ensure the accuracy of this data, the Department accepts no responsibility for any inaccuracies and persons relying on this data do so at their own risk.
Gnangara sustainability strategy appendix 1: Gnangara groundwater system zone plans Draft for public comment
GSS 3 ISBN 978-1-921637-43-8 (print) 978-1-921637-44-5 (online) ISSN 1836-1528 (print) 1836-1536 (online)
Cover image Housing meets horticulture. Image supplied by the Department of Water. Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
Contents
Gnangara groundwater system zone plans 1
Introduction 1 1 Zone 1 plan – West Gnangara, East Gnangara, Gnangara and Whiteman subareas 1
1.1 Overview 1
1.2 Allocation status of Zone 1 4
1.3 Issues 5
1.4 Objectives 5
1.5 Recommendations for the whole of Zone 1 with associated benefi ts and risks 6
1.6 Recommendations to address the water and land management issues in Zone 1 8
1.6.1 Public water supply management 8
1.6.2 Urbanisation and commercial use 8
1.6.3 Land use management 11
1.6.4 Biodiversity 14 2 Zone 2 plan – Carabooda, West Pinjar, Nowergup, Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas 18
2.1 Overview 18
2.2 Allocation status of Zone 2 19
2.3 Issues 20
2.4 Objectives 20
2.5 Recommendations for the whole of Zone 2 with associated benefi ts and risks 21
2.6 Recommendations to address water and land management issues in Zone 2 23
2.6.1 Public water supply management 23
2.6.2 Urbanisation and commercial use 23
iii Gnangara Sustainability Strategy Appendix 1 Contents Gnangara groundwater system zone plans
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2.6.3 Land use management 27
2.6.4 Biodiversity 30 3 Zone 3 plan – Bullsbrook, Ellenbrook Town and West Swan subareas 34
3.1 Overview 34
3.2 Allocation status of Zone 3 34
3.3 Issues 36
3.4 Objectives 36
3.5 Recommendations for the whole of Zone 3 with associated benefi ts and risks 37
3.6 Recommendations to address water and land management issues in Zone 3 39
3.6.1 Public water supply management 39
3.6.2 Urbanisation and commercial use 40
3.6.3 Land use management 41
3.6.4 Biodiversity 43 4 Zone 4 plan – Quinns Rock, Eglinton and Yanchep–Two Rocks subareas 45
4.1 Overview 45
4.2 Allocation status of Zone 4 45
4.3 Issues 46
4.4 Objectives 47
4.5 Recommendations for the whole of Zone 4 with associated benefi ts and risks 48
4.6 Recommendations to address water and land management issues in Zone 4 49
4.6.1 Public water supply management 49
4.6.2 Urbanisation and commercial use 50
4.6.3 Land use management 52
4.6.4 Biodiversity 53 5 Zone 5 plan – Gingin Brook 1,2,3 and 4 and Lake Mungala subareas 56
5.1 Overview 56
5.2 Allocation status of Zone 5 56
5.3 Issues 58
iv Gnangara Sustainability Strategy Appendix 1 Contents Gnangara groundwater system zone plans
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5.4 Objectives 58
5.5 Recommendations for the whole of Zone 5 with associated benefi ts and risks 59
5.6 Recommendations to address water and land management issues in Zone 5 60
5.6.1 Public water supply management 60
5.6.2 Urbanisation and commercial use 60
5.6.3 Land use management 61
5.6.4 Biodiversity 63 6 Zone 6 plan – West Yanchep, East Yanchep and Banksia subareas 65
6.1 Overview 65
6.2 Allocation status of Zone 6 66
6.3 Issues 67
6.4 Objectives 67
6.5 Recommendations for the whole of Zone 6 with associated benefi ts and risks 68
6.6 Recommendations to address water and land management issues in Zone 6 70
6.6.1 Public water supply management 70
6.6.2 Urbanisation and commercial use 70
6.6.3 Land use management 72
6.6.4 Biodiversity 75 7 Zone 7 plan – Whitfords, Gwelup, Perth North and Cottesloe Peninsula subareas 79
7.1 Over view 79
7.2 Allocation status of Zone 7 80
7.3 Issues 81
7.4 Objectives 81
7.5 Recommendations for the whole of Zone 7 with associated benefi ts and risks 82
7.6 Recommendations to address the water and land management issues in Zone 7 83
7.6.1 Public water supply management 83
7.6.2 Land use management 85
7.6.3 B i o d i ve r s i t y 86
v Gnangara Sustainability Strategy Appendix 1 Contents Gnangara groundwater system zone plans
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List of fi gures
Figure 1 GSS subareas grouped into seven zones according to land use similarities 2
Figure 2 Zone 1 2008 licensed groundwater allocation – 39.9 gigalitres 3
Figure 3 Zone 1 public water supply borefi elds 17
Figure 4 Zone 2 2008 licensed groundwater allocation – 27.6 gigalitres 19
Figure 5 Zone 2 public water supply borefi elds 33
Figure 6 Zone 3 2008 licensed groundwater allocation – 16.6 gigalitres 35
Figure 7 Zone 3 public water supply borefi elds 44
Figure 8 Zone 4 2008 licensed groundwater allocation – 27.7 gigalitres 46
Figure 9 Zone 4 public water supply borefi elds 55
Figure 10 Zone 5 2008 licensed groundwater allocation – 23.6 gigalitres 57
Figure 11 Zone 6 2008 licensed groundwater allocation – 11.2 gigalitres 66
Figure 12 Zone 6 public water supply borefi elds 78
Figure 13 Zone 7 2008 licensed groundwater allocation — 84.6 gigalitres 80
Figure 14 Zone 7 public water supply borefi elds 89
Figure 15 Department of Water gazetted groundwater subareas 90
vi Gnangara groundwater system zone plans Introduction Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
The Gnangara sustainability strategy’s appendix 1: Gnangara groundwater system zone plans provide details of land use and water management at the subarea scale.
For the purposes of developing the Gnangara sustainability strategy (GSS), the area covering the Gnangara groundwater system was subdivided into 30 subareas. These subareas were grouped into seven zones according to hydrological and land use similarities (Figure 1). Sections 1 to 7 provide an overview, highlight the major issues and list the GSS recommended options for each zone.
This document should be read in conjunction with the Gnangara sustainability strategy situation statement, which provides the context for the GSS itself. The Situation statement provides detailed background description and highlights issues surrounding land and water use of the Gnangara groundwater system taken from current literature, government planning documents and government reports. It also presents an overview of governance mechanisms associated with land and water use of the system.
1 Gnangara Sustainability Strategy Appendix 1 Introduction Gnangara groundwater system zone plans
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Figure 1 GSS subareas grouped into seven zones according to land use similarities
2 Zone 1 plan – West Gnangara, East Gnangara, Gnangara and Whiteman subareas Zone 1 Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
1.1 Overview Land Percentage of Subarea area ha total GSS area A main feature of Zone 1 is that it is predominantly crown land. Commercial pine plantation forestry is Gnangara 7666 3.6 the main land use within the Gnangara and West Gnangara subareas. Native Banksia woodland East Gnangara 6361 3.0 occurs on the East Gnangara subarea whilst Whiteman Park, as a regional recreation and West Gnangara 4096 1.9 conservation reserve, dominates the Whiteman subarea. Whiteman Park, managed by the Whiteman 4306 2.0 Department for Planning and Infrastructure, links to Gnangara Park over state forest managed by Local governments the Department of Environment and Conservation. These parks have regional ecological and social City of Wanneroo, Shire of Chittering, City of Swan values and offer diverse recreational and tourism Population in 2006 opportunities. Bush Forever sites are located across the zone, protecting regionally important bushland Gnangara – 26, East and West Gnangara – 0, and associated wetlands. Extensive sandmining Whiteman – 55 tenements are also present in this zone. Land form (surface geology) Zone 1 is bounded by urban land on the southern boundary of Whiteman Park, private property in Bassendean Dunes, lacustrine (peat, peaty sands) East Wanneroo to the west, rural holdings and Ellenbrook townsite to the east, and Banksia Wetlands woodland on state forest or RAAF managed lands to the north. The majority of the zone exists within Wetlands in Lexia and Melaleuca groups (21 the Priority 1 Water source protection area and is ministerial criteria sites), Horse Swamp, Hawkins predominantly publicly owned. Road Swamp, Bustard Swamp, Mussel Pool, Bennett Brook Currently there are signifi cant licensed allocations for public water supply and investment in public water Indigenous sites of signifi cance supply infrastructure. 19, including Bennett Brook, Payne Road, Mussel Pool, Beechboro Road
3 Zone 1 – West Gnangara, East Gnangara, Gnangara Sustainability Strategy Appendix 1 Zone Gnangara and Whiteman subareas Gnangara groundwater system zone plans
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1.2 Allocation status of Zone 1 • The current water management strategy in over allocated areas is to cap use (so no new licences are issued), reduce use The GSS zone and subarea boundaries differ from through effi ciency, and recover water where the current water allocation management area licensing processes allow. boundaries used by the Department of Water. The Gnangara groundwater area is proclaimed in • A small volume of water is available from the accordance with s.26B of the Rights in Water and State Forest and Beechboro groundwater Irrigation Act 1914 (Figure 15). subareas.
As of December 2008 the licensed groundwater • There is no additional water available from allocation status for gazetted groundwater subareas the Mirrabooka, Leederville or Yarragadee which fall within GSS Zone 1, is as follows (see aquifers in this zone. Figure 2): Predicted continued reduction in recharge from rainfall will reduce water availability in future years. Appropriate • The draft Gnangara groundwater areas changes in current land use may alter this trend. management plan (2008) set allocation limits which indicate that groundwater subareas In Zone 1 the GSS recommends that the area in the Superfi cial aquifer are 30.6 to 171 per under pines be largely replaced by parkland that cent allocated under the current climate and is managed to increase recharge. Water balances current land and water use.
Figure 2 Zone 1 2008 licensed groundwater allocation – 39.9 gigalitres
4 Gnangara Sustainability Strategy Appendix 1 Zone 1 – West Gnangara, East Gnangara, Zone Gnangara groundwater system zone plans Gnangara and Whiteman subareas
July 2009
from PRAMS show that if this landuse change • the demand for land uses which generate occurs, storages will recover within about fi ve years local employment, to avoid the rapidly of pine removal and then reach an equilibrium with growing populations in the north-west and the new climate by 2030, assuming no further north-east corridors having to commute long drying occurs. Some increases in abstraction for distances for work public water supply may be possible from the State Forest and Beechboro groundwater subareas • the need for additional urban land to support under this new land use. This would enable the Wanneroo Activity Centre drinking water to be made available for expansion • the need for major north-south and east- at Ellenbrook and Upper Swan and some recovery west transport linkages of the Lexia wetlands. 1.4 Objectives In addition to the licensed use of water outlined above, it is estimated that approximately 2.5 The objectives of the Gnangara sustainability gigalitres of water is abstracted from the Superfi cial strategy for Zone 1 are to: aquifer for unlicensed use. Unlicensed use includes taking of water for stock and domestic purposes in addition to use for domestic garden bores. • protect the public water supply resource and assets
1.3 Issues • maintain and protect the existing Banksia woodland and remnant bushland
The most important issues that need to be • manage Phytophthora cinnamomi dieback addressed within Zone 1: • rehabilitate degraded parts of identifi ed • the determination of appropriate post-pine regional ecological linkages land use for approximately 7000 hectares in • protect signifi cant wetlands and Gnangara pine plantation groundwater dependent ecosystems • the existence of European House Borer in • continue access to mine basic raw materials the Gnangara pine plantation and maximise sandmining from disturbed • the confl icts arising from burning and smoke areas, thus protecting bushland haze which affect residences in adjacent • maximise sustainable water and energy subareas production (wind, bio-energy, solar) • the occurrence and possible intensifi cation • prevent the formation of acid sulphate soils of acid sulphate soils • promote tourism and recreation activities • the increasing demand for public water and facilities supply • accommodate new transport corridors to • the managing of ‘stranded’ public water meet Network City objectives supply assets • provide employment generating land to • the reduction in water levels and functional service growing populations condition of wetlands and damplands • provide additional urban land to support • the demand for passive recreational facilities Wanneroo Activity Centre in accordance to cater for the expanding urban areas in with Network City principles the surrounding areas of East Wanneroo, Ellenbrook and Caversham which may • protect Indigenous heritage. increase groundwater demand pressures
5 Zone 1 – West Gnangara, East Gnangara, Gnangara Sustainability Strategy Appendix 1 Zone Gnangara and Whiteman subareas Gnangara groundwater system zone plans
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1.5 Recommendations for the whole of Zone 1 with associated benefi ts and risks
Recommendation Benefi ts Risks
1. It is recommended that no • Increased groundwater • Local residents’ loss of tree amenity further commercial pine recharge • Loss of recreational opportunities replanting be undertaken in • Control of European House • Loss of commercial timber production, value adding Gnangara plantation. Borer and related employment • In line with the government • Loss of food source for the endangered Carnaby’s commitment to remove pine black-cockatoo plantations • In subareas where there is no further replanting of pines • General public support for this, the Gnangara sustainability strategy’s recommended and little support for retaining post-pine landuse may need to be assessed under the pines Environment Protection and Biodiversity Conservation • Simplifi ed governance Act 1999 (EPBC Act), which protects nationally listed threatened species such as the Carnaby’s black- cockatoo • Transference of management costs • Lost opportunity for carbon credits • A carbon defi cit
2. It is recommended that • Increased biodiversity and • High cost of establishment regional ecological linkages increased resilience of • Precludes alternative land uses across the Gnangara and ecosystems to climate change • Decreases ability to maximise recharge West Gnangara subareas be • Retention of social amenity • Ongoing maintenance and decision as to who pays established. and landscape values • Cleared pine plantation and parkland areas may be • More cost effective than perceived as undeveloped land with potential for urban returning whole area to native development woodland • Higher recharge than under current commercial pines and widespread rehabilitation to native bush • All on existing crown land vested with the Conservation Commission
3. It is recommended that • Increased recharge and • Potential to temporarily mobilise acidifi ed soil layers if outside the proposed watertable water tables rise while slowing the formation of more ecological linkages, cleared • Increased potential recharge acidity by reduced drying plantation areas should be coincides with high number of • Uncertainty with management implications of a parkland managed to protect the public water supply bores and option groundwater resource and infrastructure • Funding for the initial and ongoing management of a to increase recharge around • Water table benefi ts for parkland option have not been identifi ed bore fi elds for public water many signifi cant wetlands • Ongoing maintenance and the need for a decision as to supply. and groundwater dependent who pays for and manages the cleared plantation areas ecosystems
6 Gnangara Sustainability Strategy Appendix 1 Zone 1 – West Gnangara, East Gnangara, Zone Gnangara groundwater system zone plans Gnangara and Whiteman subareas
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1.5 Recommendations for the whole of Zone 1 with associated benefi ts and risks
Recommendation Benefi ts Risks
4. It is recommended that • Urban consolidation and • Contamination risk of groundwater resources identifi ed areas on the edge sustainability benefi ts • Potential loss of vegetation amenity of crown land be investigated associated with a more • Removal of disturbed buffer area protecting high quality with a view to their excision compact urban form native vegetation from disturbance for urban deferred or • Proximity to services and • Excision of Priority 1 and Priority 3 Water source industrial development employment opportunities in protection areas requires change to Metropolitan to provide employment an area of low employment Region Scheme and State planning policy and related generating land for strategic • Revenue generation for crown legislation employment categories. land management • Carbon emission on clearing (Refer to GSS Figure 11) • Possible increased water • Carbon balance reduced recharge from urban area • Potentially little impact on conservation values if located appropriately • Maintenance of reserve integrity as they are on the edge of crown land • Reduction in impacts associated with long distance travel to places of employment
1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.1 1.6.1.1 • Public water supply and bores (Figure It is recommended that: Public water supply Public water 3): 1. outside proposed linkages, cleared management supply o Zone 1 borefi elds: Pinjar, East plantation areas should be managed Wanneroo Lexia, and East to increase recharge around bore Mirrabooka; plus Wanneroo and fi elds and protect the quality of the Lexia water treatment plants groundwater resource for public water o 2007–08 borefi eld abstraction was supply. 39. GL 2. a project be undertaken to defi ne the o abstraction by aquifer: Superfi cial ecology, water use and management of 14.5 GL, Leederville 13.43 GL and parkland option for promoting recharge Yarragadee 11.32 GL in borefi elds and windows to the • Much of Zone 1 lies within the Priority 1 confi ned aquifers. Water source protection area 3. a project be undertaken to investigate • Clearing of pine plantations may lead the possibilities for co-locating wind, to increased groundwater levels around solar energy and bio-energy production Lexia borefi eld with recharge enhancement. This would supply the adjacent urban area with water and energy to make the area self- suffi cient. 4. consideration be given to increase the yield from Lexia borefi eld if recharge is enhanced post-pines and the environment can be maintained, before investigations into alternative supplies.
7 Zone 1 – West Gnangara, East Gnangara, Gnangara Sustainability Strategy Appendix 1 Zone Gnangara and Whiteman subareas Gnangara groundwater system zone plans
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1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.2 1.6.2.1 • Zone 1 is particularly well located It is recommended that: Urbanisation and Urban relative to other land within the 5. the amending of the Priority 1 boundary commercial use development Metropolitan region given its proximity be investigated to permit the possible to the Central Business District and expansion of the East Wanneroo area to associated infrastructure. Network City address the need for additional urban encourages the development of such land adjacent to the existing City of land where possible which will lead Wanneroo Regional Activity Centre. to a more compact urban form and 6. any excision of Department of associated benefi ts Environment and Conservation • There is a demand for new urban land or Western Australian Planning in East Wanneroo to increase the urban Commission managed lands be used to catchment of the City of Wanneroo generate funding for rehabilitation works Regional Activity Centre in ecological linkages or land swaps for • No urban growth is currently permitted priority conservation land. within Zone 1 given the Priority 1 Water 7. existing bushland remnants, Bush source protection area classifi cation and Forever sites, proposed ecological amending the Priority 1 boundary to linkages and Whiteman Park not be meet demand should be investigated cleared and possible excisions only made on cleared land on the edge of crown land blocks.
1.6.2.2 • Transport modelling undertaken for It is recommended that: Requirement the North West corridor structure plan 8. opportunities for new east-west and for transport indicates that major new east-west and north-south transport corridors required corridors north-south transport corridors are to accommodate growth in the north- required to accommodate growth in the west and north-east corridors and north-west and north-east corridors and to meet Network City objectives be to meet Network City objectives investigated. 9. all proposed new transport corridors take into account the impact on the environment and the integrity of bushland blocks.
8 Gnangara Sustainability Strategy Appendix 1 Zone 1 – West Gnangara, East Gnangara, Zone Gnangara groundwater system zone plans Gnangara and Whiteman subareas
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1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.2.3 • Research undertaken for the North It is recommended that: Requirement West corridor structure plan indicates 10. consideration be given to Zone 1 for the for that land suitable for employment location of critically important strategic employment generation, particularly in the strategic employment generating uses that generating employment categories of research and require large areas of land. Possible land development, is in critically short supply uses could include research and in the north-west corridor development, industrial, correctional • Employment self-suffi ciency is 38.3%, services, educational institutions and with approximately only 50 000 jobs related uses that are compatible with currently being available in the corridor. Priority 3 classifi cation. For an employment self-suffi ciency 11. further planning and environmental target of 72% – the target adopted assessment be completed for areas by state parliament’s North-West on the edge of crown land to assess Corridor Coordination Committee – their suitability for excision to provide approximately 95 000 jobs are required employment generating development. • If the north-west corridor continues to These areas include: develop with its current development • State forest (up to 720 ha) on the format, overall employment self- corner of Neaves and Pinjar roads suffi ciency would only be 42% • State forest (up to 500 ha) south of • The current and projected jobs shortfall Neaves Road and west of Quail Road requires immediate measures to • Western Australian Planning increase employment opportunities in Commission owned land (up to 120 the short term, as well as long-term ha) on the southern boundary of strategies Whiteman Park, adding to Malaga • The draft Industrial land needs study Industrial Area (DPI Land Corp 2008) identifi ed the • A section of land in the south-west need for an additional 730 ha in the portion of West Gnangara could be north-west corridor which includes part excised from the Priority 1 Water of Zone 1. The most suitable location for source protection area and may be industry will be determined in Stage 2 of suitable for extending the Neerabup the study industrial area or for the extension of urban development. 12. consideration of excising the above areas from the Priority 1 Water source protection area classifi cation and conversion to Priority 3 would be required. 13. development and land uses include measures to prevent adverse effects on water quality. These could include directing all water from hard surfaces and wastewater away from public drinking water source areas.
9 Zone 1 – West Gnangara, East Gnangara, Gnangara Sustainability Strategy Appendix 1 Zone Gnangara and Whiteman subareas Gnangara groundwater system zone plans
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1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.2.4 • The City of Swan is working to secure 14. It is recommended that the City of Requirement a site of approximately 80 ha for Swan evaluate the utilisation of the for regional a regional sporting complex to fi ll south-east corner of the Gnangara open space an identifi ed gap in provision in the pine plantation, the south-east area of north-east corridor. The City and Whiteman Park or another degraded the Department of Environment and area including Bullsbrook for regional Conservation have identifi ed a site in the recreation facilities. The availability of Gnangara subarea as being potentially irrigation water needs to be a major part suitable and these facilities could be of the investigation and water effi cient appropriate in this zone measures need to be adopted.
1.6.2.5 • Cleared pine areas and degraded 15. It is recommended that the compatibility Requirement sites in this zone may be suitable for of civic and institutional uses with the for civil and civil, institutional type uses and other constraints of being in a Priority 1 area institutional employment generating uses subject be investigated for future needs. areas to investigations that can confi rm the potential impacts on groundwater resources
1.6.2.6 • A ready supply of basic raw materials It is recommended that: Extraction close to established and developing 16. basic raw materials (principally sand) of basic raw parts of the Metropolitan region is existing within Zone 1 be extracted to materials essential to keep land development meet the high demand in the Perth–Peel costs down and contribute to affordable region. housing. Priority resource locations and 17. in order to extract basic raw materials key extraction areas as defi ned inState without compromising future long- planning policy 2.4 Basic raw materials term development for urban and other July 2000 are shown in Figure 3.11 of purposes, sequential land use planning the Situation statement should be undertaken to make sure that extraction and rehabilitation can take place in a controlled way. 18. the availability of suitable road access be assessed. 19. extraction operations be staged to avoid confl icts with adjacent land use. 20. preference be given to mining operations on already cleared lands to ensure that mining tenements exclude remnant vegetation areas.
10 Gnangara Sustainability Strategy Appendix 1 Zone 1 – West Gnangara, East Gnangara, Zone Gnangara groundwater system zone plans Gnangara and Whiteman subareas
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1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.3 1.6.3.1 • Whiteman Park and the southern part It is recommended that: Land use Gnangara of Gnangara Park are in close proximity 21. Whiteman Park and Gnangara Park management Park and and have high conservation value, be retained and their management Whiteman regional recreational value, tourism integrated and resourced as key Park value and a sense of place. These icon regional tourism, recreation and parks could be managed by a single conservation reserves. agency 22. Gnangara off road vehicle area be • Gnangara and Whiteman parks cater retained and resourced in the medium for active and regionally important term (between fi ve and ten years) and recreational activities that may need upgraded for the safe use of riders buffers from housing or other uses (as recommended in the report from • The Gnangara off road vehicle area Trail Bike Management Australia 2008) (ORVA) is 361 ha in area, has a capacity and for the protection of groundwater of about 1000 riders a day and is located resources. on state forest on the corner of Gnangara 23. the Department of Environment and Road and Centre Way. It provides a Conservation prepare a CALM Act legal opportunity for riders of non-road 1984 area management plan for registered motorcycles and quad bikes, Gnangara Park incorporating the and people who do not hold a driver’s GSS recommendations adopted by licence, to ride on public land. A recent government. review of the Gnangara and Pinjar ORVAs for the Department of Environment and Conservation has recommended their retention and upgrade for the safety of riders Other recreational uses in Gnangara and Whiteman parks include: o horse trail – a long distance horse trail from East Wanneroo to Moore River o dual use paths – a series of dual use and walking trails are proposed for Whiteman Park and Gnangara Park to be used by park neighbours and as regional recreational resources o shooting ranges – shooting complexes in state forest off Perry Road (managed by the City of Wanneroo) and in Whiteman Park (managed by Western Australian Planning Commission) will be retained. A new shooting range (to replace the Swanbourne facility) in state forest 65 in the north-east corner of Gnangara plantation is proposed on ex-plantation land o regional sporting grounds for the cities of Wanneroo and Swan
11 Zone 1 – West Gnangara, East Gnangara, Gnangara Sustainability Strategy Appendix 1 Zone Gnangara and Whiteman subareas Gnangara groundwater system zone plans
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1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.3.2. • The state government has two major It is recommended that: Pine timber-supply agreements – WESFI and 24. standing pine be commercially plantation Wesbeam – which require a continuous removed from Gnangara plantation supply of softwood timber until the end in a targeted program by the Forest of 2025 and 2029 respectively. There Products Commission (FPC) and no is no agreement to replant harvested further commercial pine replanting be areas with pine or other commercial undertaken in the Gnangara plantation. forestry species. 25. the cleared plantation areas of • Since 2002, 20 per cent of the total Gnangara and West Gnangara subareas plantation area has been clear-felled should be managed to protect the and is fallow groundwater resource and to increase • The following table shows the area of recharge around public water supply land covered by pine plantation and the bores. Options for post-pine are still percentage of remaining plantation to being considered. be harvested 26. the community (particularly at Ellenbrook and East Wanneroo) be Sept 2002 Remaining kept informed of transitional plans Plantation 2008 ha % and actions in removing pines and ha establishing new land uses. Gnangara 6457 3558 55 27. the Department of Agriculture and Pinjar 7598 6741 89 Food WA (EHB Unit), FPC and the Yanchep 7392 7089 96 Department of Environment and Total 21 447 17 395 81 Conservation (DEC) continue to work cooperatively during FPC harvesting • Under the current harvesting regime operations, the EHB control program, of around 1000 ha of clear-fall per pine wilding control, retention of annum across zones 1,2 and 6, the pine specimen/shade trees (if possible), post- plantations will be removed by 2026 pine revegetation by DEC and working with the community to incorporate sense of place values. 28. the community values of life and property, plus the commercial timber resource, be protected from destructive wildfi res.
1.6.3.3 • The discovery in 2004 of the introduced 29. It is recommended that the commercial European European House Borer (EHB) in the use of plantation residues and stumps House Borer Gnangara pine plantation and adjoining for bioenergy or other uses be suburbs, including Ellenbrook, has supported to assist European House added weight to the need for removing Borer control in infected pine plantations pine earlier from this plantation and their buffers • Collaboration between DAFWA (EHB Unit), FPC, and the DEC is systematically removing standing pine, pine timber debris and pine stumps from a 2km buffer between the plantation and urban development. This process would be signifi cantly assisted with the development of a bio-fuel plant that commercially uses the pine debris and stumps
12 Gnangara Sustainability Strategy Appendix 1 Zone 1 – West Gnangara, East Gnangara, Zone Gnangara groundwater system zone plans Gnangara and Whiteman subareas
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1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.3.4 • Alternative forest species and 30. It is recommended that alternative forest Alternative management systems need to be species that will enable recharge be forestry identifi ed which: identifi ed. species o may replace areas of previous plantations o have a suffi ciently low average density to allow groundwater recharge equivalent to Banksia woodland. • Eucalypt species such as Eucalyptus cladocalyx may be suitable, as the primary product is a saw log, requiring heavy early culling within the stand and pruning at different stages to produce the product
1.6.3.5 • In Zone 1, broadscale mapping has 31. It is recommended that monitoring and Acid sulphate identifi ed the subareas as having investigation of potential acid sulphate soils moderate to low risk of acid sulphate soils be undertaken. soils (ASS), except in areas where there are peaty wetland sediments where the risk of ASS is high to moderate • Recent preliminary data show that in these subareas, pH in the watertable is low and the concentration of metals in the soil profi le is high • An investigation into groundwater and soil acidity is currently underway in this area
13 Zone 1 – West Gnangara, East Gnangara, Gnangara Sustainability Strategy Appendix 1 Zone Gnangara and Whiteman subareas Gnangara groundwater system zone plans
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1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.4 1.6.4.1 • The GSS has identifi ed patches of intact It is recommended that: Biodiversity Ecological remnant vegetation for retention with the 32. ecological linkages, consisting of linkages aim of rehabilitating the adjoining areas existing remnant bushland and new to form regional ecological linkages linkages be established across the • The majority of the East Gnangara Gnangara and West Gnangara subareas subarea retains its native vegetation, to link Whiteman Park and the Banksia except in small patches around the woodland surrounding the pine sand mine and private property plantation. locations. This zone provides major 33. degraded vegetation in the Bush regional ecological linkages between Forever sites be rehabilitated. Whiteman Park to the south, Gnangara Park to the north and east, and into the Darling Scarp • Phytophthora cinnamomi dieback is widespread in this zone and represents a major threat to biodiversity, vegetation communities and habitat structure • Only 22% of the Gnangara and West Gnangara subareas remain as bushland. Bush Forever (WAPC 2000) identifi ed fi ve regional ecological linkages and the Perth Biodiversity Plan (WALGA 2004) identifi ed eight linkages across this zone. The GSS proposes that 12 ecological linkages, consisting of existing remnant bushland and new linkages, covering 9298 ha, be established across the Gnangara and West Gnangara subareas following clearance of pines. There will also be a need to rehabilitate some of the degraded vegetation in the two major linkages through Whiteman Park • Approximately 40% of the land (1922 ha) within these linkages will need to be rehabilitated to link large areas of bushland in Gnangara Park, Whiteman Park and several east–west linkages across the ex-plantation areas
14 Gnangara Sustainability Strategy Appendix 1 Zone 1 – West Gnangara, East Gnangara, Zone Gnangara groundwater system zone plans Gnangara and Whiteman subareas
July 2009
1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.4.2 • Two declared rare fl ora and fi ve species It is recommended that: Threatened of priority fl ora are present in Zone 1 34. threatened fl ora, fauna and fl o r a , • The endangered threatened ecological ecological communities be managed fauna and community, SCP 20a Banksia attenuata in accordance with the Wildlife ecological woodland, has four occurrences in the Conservation Act 1950 (WA), and the communities Whiteman subarea. Threats include relevant recovery plans for threatened continued clearing for development, and priority species and ecological lowering of the groundwater level, communities. climate change, invasive weeds and 35. where applicable, threatened fl ora, the introduced pathogen Phytophthora fauna and ecological communities cinnamomi also threaten this community be managed in accordance with the • Two priority listed reptile species Environment Protection and Biodiversity are present in the East Gnangara Conservation Act 1999 (Cwlth). and Whiteman subareas along with 36. further research into population signifi cant populations of the priority demography, size and habitat and food listed mammals (Quenda, Black-gloved resource (native woodland and pine Wallaby) plantation) preference and availability • Signifi cant frog populations and frog of Carnaby’s black-cockatoo be breeding sites are scattered throughout undertaken. • The endangered Carnaby’s black- cockatoo (Calyptorhynchus latirostris) occurs throughout the zone. Both the Gnangara pine plantation and the surrounding remnant native vegetation represent important foraging habitat for this species • Zone 1 post-pine landuse presents signifi cant opportunities to re-establish or improve habitat associated with linkages, existing bushland and recharge zones for the Carnaby’s black- cockatoo
15 Zone 1 – West Gnangara, East Gnangara, Gnangara Sustainability Strategy Appendix 1 Zone Gnangara and Whiteman subareas Gnangara groundwater system zone plans
July 2009
1.6 Recommendations to address the water and land management issues in Zone 1
Management Issue Explanation Recommendations consideration
1.6.4.3 • There are few effective options available It is recommended that: Wetlands and for managing some wetlands under 37. in order to develop a greater groundwater drying climate scenarios where there understanding of the use of wetlands dependent is either a long lag time in groundwater by waterfowl and other aquatic species, ecosystems recovery or no recovery, and/or where and the impacts from the loss of there is a severe impact from acid wetlands along much of the Swan sulphate soils coastal plain, wetland biodiversity • Zone 1 overlies shallow groundwater values and wetland complexes be and contains numerous wetlands in identifi ed and prioritised in a regional the Lexia and Melaleuca groups, 21 of context. which are ministerial criteria sites. Some 38. the feasibility of maintaining or increases in groundwater levels are recovering wetlands affected by expected after pine removal groundwater decline and acid sulphate • The wetlands are all potentially acidic soils be determined. sumplands or damplands on grey 39. local area models be developed sands with many including peat and to determine wetlands and other diatomaceous earths. Drying and groundwater dependent ecosystems burning of the wetlands will pose a most at risk from declining water levels. high risk from acid sulphate soils and 40. areas surrounding wetland be associated heavy metals managed to increase recharge by using • No permanent lakes, streams or rivers stormwater and treated wastewater exist in this zone. There are seasonal streams to manage local groundwater tributaries of the Bennett Brook and levels. patches of palusplain in Whiteman Park 41. further analyses of risks and cost- benefi ts of management options be undertaken. 42. remaining wetlands and groundwater dependent ecosystems be monitored and protected from development. 43. it be determined whether there are any wetlands or groundwater dependent ecosystems that should be incorporated into any future review of ministerial criteria sites.
16 Gnangara Sustainability Strategy Appendix 1 Zone 1 – West Gnangara, East Gnangara, Zone Gnangara groundwater system zone plans Gnangara and Whiteman subareas
July 2009
Figure 3 Zone 1 public water supply borefi elds
17 Zone 2 plan – Carabooda, West Pinjar, Nowergup, Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas Zone 2 Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
2.1 Overview Neerabup 1759 0.8
Zone 2 contains signifi cant numbers of high quality Carramar 1319 0.6 wetlands, lakes and groundwater dependent ecosystems. Land use within the zone includes a Mariginiup 3019 1.4 signifi cant area of horticulture on relatively small rural holdings, which is reliant on groundwater, and urban Lake Gnangara 1895 0.9 areas within the City of Wanneroo. Local government This zone is the focus of The future of east City of Wanneroo Wanneroo: Land use and water management in the context of Network City. This plan integrates land Population in 2006 use planning and future development with water resource planning objectives, the allocation of land Carabooda – 448, West Pinjar – 0, Nowergup – 211, for horticultural uses, the protection of access to Lake Pinjar – 77, Nerrabup – 85, Carramar – 9026, basic raw materials and the protection of the lakes Mariginiup – 1536, Lake Gnangara – 1737 for the benefi t of the whole community. A structure plan for the zone is being developed and will result Land form (surface geology) in signifi cant urbanisation of the southern two thirds of Zone 2, which may assist with the recharge of Spearwood, Tamala Limestone groundwater to the system and to the important lakes in this zone. Wetlands
Lake Neerabup, Lake Pinjar, Nowergup Lake, The subareas within Zone 2 are bounded by urban Lake Gnangara, Lake Mariginiup, Lake Jandabup, land and recreational areas on the western boundary, Carabooda Lake, Coogee Swamp, Mindarie Lake, industrial and urban land to the south, Yanchep Camel Swamp, Lake Adams, Little Mariginiup, Snake National Park and state forest to the north, and Swamp, Little Dundabar Swamp, Ballanup/Badgerup Gnangara pine plantation on state forest to the east. Lake, Little Badgerup Swamp, Wilgarup Lake
Indigenous sites of signifi cance Percentage of Subarea Land area ha 17, including Lake Neerabup, Lake Mariginiup, total GSS area Gnangara Lake, Lake Adams
Carabooda 1815 0.8
West Pinjar 1663 0.8
Nowergup 1692 0.8
Lake Pinjar 2803 1.3
18 Gnangara Sustainability Strategy Appendix 1 Zone 2 – Carabooda, West Pinjar, Nowergup, Zone Gnangara groundwater system zone plans Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas July 2009
2.2 Allocation status of Zone 2 • A small volume of water is available from the Carramar, Joondalup and Neerabup groundwater subareas. The GSS zone and subarea boundaries differ from the current water allocation management area • There is no additional water available from boundaries used by the Department of Water. the Mirrabooka, Leederville or Yarragadee The Gnangara groundwater area is proclaimed in aquifers in Zone 2. accordance with s.26B of the Rights in Water and Irrigation Act 1914 (Figure 15). Predicted continued reduction in recharge from rainfall will reduce water availability in future years. As of December 2008 the licensed groundwater Changes in current land use may alter this trend. allocation status for gazetted groundwater subareas which fall within GSS Zone 2, is as follows (see Figure 4): In Zone 2 the GSS recommends that private licensed abstraction be reduced, and recharge enhanced, by • The draft Gnangara groundwater areas urbanising signifi cant parts of the Lake Mariginiup management plan (2008) set allocation limits and Lake Gnangara subareas as part of The future which indicate that groundwater subareas of east Wanneroo: Land use and water management in the Superfi cial aquifer are 88 to 140 per in the context of Network City. cent allocated under the current climate and current land and water use. The GSS also recommends that in the future water be allocated as a periodic share of available water • The current management strategy in over enabled through the statutory water management allocated areas is to cap use (so no new plan. This will enable allocations to refl ect the inter- licences are issued), reduce use through annual and seasonal availability of water. effi ciency and recover water where licensing processes allow.
Figure 4 Zone 2 2008 licensed groundwater allocation – 27.6 gigalitres
19 Zone 2 – Carabooda, West Pinjar, Nowergup, Gnangara Sustainability Strategy Appendix 1 Zone Lake Pinjar, Neerabup, Carramar, Mariginiup Gnangara groundwater system zone plans and Lake Gnangara subareas July 2009
In addition to the licensed use of water outlined • maintain and retain sense of place with the above, it is estimated that approximately 0.28 rural nature of Zone 2, including sense of gigalitres of water is abstracted from the Superfi cial place associated with land use for horticulture aquifer for unlicensed use. Unlicensed use includes taking of water for stock and domestic purposes in • integrate the management of land and water addition to use for domestic garden bores. use for East Wanneroo • maximise local employment opportunities 2.3 Issues • maintain water quality for downstream public water supply The most important issues that need to be addressed within Zone 2: • protect high value biodiversity assets and create ecological linkages • the development, currently in progress, of • recover over-allocations of groundwater a new structure plan for East Wanneroo, proposing the intensifi cation of development, • accommodate new transport corridors to which will change land use signifi cantly meet Network City objectives
• the demand for land uses which generate • provide employment generating land to local employment, to avoid the rapidly service growing populations growing populations in the north-west and north-east corridors who need to commute • provide additional urban land to support long distances to work Wanneroo Activity Centre in accordance with Network City principles • the need for major north-south and east- west transport linkages • minimise carbon footprints
• the need to evaluate the continued use of • maximise recreational opportunities Carabooda and Neerabup subareas for • allow for continuing extraction of basic raw horticulture and its ongoing water supply in materials (principally limestone) the medium to long term • determine appropriate post-pine land use for • the already signifi cant over allocation of the West Pinjar subarea (‘tear drop’ of Pinjar water resources, with the added pressure of pine plantation) such as low density forestry, off increased demand from urban development road vehicle area, ecological linkages, limestone in adjacent subareas and from existing mining and employment generating land uses horticulture users within the zone • consolidate purchase of land by Western • the decline in groundwater levels of four to Australian Planning Commission and its fi ve metres which have occurred in the Lake vesting and management Gnangara and Mariginiup subareas • re-evaluate any previously identifi ed • wetlands which are declining and are under groundwater source options in light of threat. updated groundwater allocation plans
2.4 Objectives • prevent the formation of acid sulphate soils and improve acid sulphate soils risk map The objectives of the Gnangara sustainability • clarify water entitlements so that groundwater strategy for Zone 2 are to: can be traded to its highest volume
• analyse and determine wetland values which • assess water recycling and supplementation are feasible to maintain opportunities
• maintain water effi cient and high value crops • protect cultural (Indigenous and European) for Perth by the protection of Nowergup and heritage. Carabooda horticulture areas 20 Gnangara Sustainability Strategy Appendix 1 Zone 2 – Carabooda, West Pinjar, Nowergup, Zone Gnangara groundwater system zone plans Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas July 2009
2.5 Recommendations for the whole of Zone 2 with associated benefi ts and risks
Recommendation Benefi ts Risks
1. It is recommended • Energy and transport • Increased population in Zone 2 will require more water that The future of east effi ciencies with the from the Integrated Water Supply Scheme Wanneroo: Land use and population living closer to key • Loss of horticultural capacity, Perth’s food security and water management in the employment centres reduced local food production context of Network City be • Promotes Network City • Altered sense of place and identity associated with East implemented. This would principles and a more Wanneroo convert horticultural areas compact urban form • Direct runoff from urban areas into wetlands could result in Lake Mariginiup and • The possibility of increased in contamination unless adequate water sensitive urban Lake Gnangara subareas to groundwater and lake design principles are followed higher density (R20) urban recharge from stormwater • Possible contamination of groundwater resources development which would runoff from the higher density • Urban impact on adjacent bushland and wetlands help maximise groundwater urban environment recharge. A local area • General land owner support model will be developed for for conversion Lake Mariginiup to provide • Economic support to fi ner scale modelling of the Wanneroo town centre impacts of urbanisation on • Horticulturalists receive capital the wetland. for retirement or expansion elsewhere • Consolidation of Perth’s urban form
2. Where it is predicted • Effective use of resources • Wetland biodiversity may be lost that wetlands will dry out • Terrestrialised ecological • Weeds may invade areas before a desirable terrestrial despite land and water communities have new values ecosystem is established management interventions, • Peat fi res it is recommended that • Community may not accept loss of wetlands management be centred on transition to a terrestrial ecosystem.
3. It is recommended that: • Horticulture is retained to • Lack of government willingness to mandate water and • horticulture is retained in the contribute to Perth’s needs for nutrient effi ciency practices Carabooda and Nowergup vegetables and fruit • Uncertainty over water and land security may affect subareas • Contributes to Perth’s future growers capacity to invest in water and nutrient • water be allocated refl ecting food security effi ciency practices a periodic share of available • Groundwater is managed • Economic effects of reduced allocations on horticulture water sustainably • horticultural practices which • Reduced impact of nutrients use water and nutrient best and water over allocation on practices and alternate downstream values production methods such as • Declining groundwater hydroponics be encouraged. levels provide motivation for investment in water effi ciency practices and better use of limited resource • Greater water use effi ciency through reduced allocations will be required
21 Zone 2 – Carabooda, West Pinjar, Nowergup, Gnangara Sustainability Strategy Appendix 1 Zone Lake Pinjar, Neerabup, Carramar, Mariginiup Gnangara groundwater system zone plans and Lake Gnangara subareas July 2009
2.5 Recommendations for the whole of Zone 2 with associated benefi ts and risks
Recommendation Benefi ts Risks
4. It is recommended that • Addresses the critical • Higher risk of contamination to Priority 3 Water source industries having a low water shortage of employment land protection area if appropriate water quality management demand be investigated to in the north-west corridor, measures are not implemented and public water supply generate employment. which has a low employment bores are re-started self-suffi ciency of 38% when • Lost opportunity for replanting trees post-pine for 72% is required amenity value • Provision of employment • Loss or transfer of the Pinjar off road vehicle area opportunities reduces need for • Carbon cost commuting • Income generation through sale of crown land where identifi ed
5. It is recommended that all • Greater water use effi ciencies • Altered urban amenity and changing of traditional new developments adopt and greater recharge landscape water sensitive urban design • Community engagement with • Ability to maintain or enforce water sensitive urban principles. water effi cient processes design is limited • Water quality improves when entering receiving bodies
6. It is recommended that: • Increased recharge of • Possible contamination of aquifer • the use of recycled water groundwater • Managing community perceptions of using recycled from Alkimos for use by • Generally supported by the water horticulture, other industries community • Managing expectations of alternative uses of limited and/or recharge to • Climate independent resource resource groundwater is re-examined that is growing at 3% per • Existing regulatory framework and governance in the future annum mechanisms need adapting • the use of recycled water • Horticulture may be viable in from Beenyup to recharge the future by using recycled groundwater is investigated water and considered within this zone.
7. It is recommended that • Increased biodiversity and • Decreased ability to maximise recharge ecological linkages be increased resilience of • High cost of establishment and on-going management established in this zone. ecosystems to climate change costs • Retention of social amenity • Precludes alternative land uses and landscape values • Ecological linkages are not adopted in structure plans • Strongly supported by the • Ecological linkages may not adapt to climate change community and therefore may lose ecological functionality • Ecological linkages are • Uncoordinated decision making by multiple agencies adopted in structure plans leading to poor outcomes and the Gnangara Park management plan • Reduced impacts on Superfi cial aquifer where confi ned aquifer connects, compared to widespread revegetation
22 Gnangara Sustainability Strategy Appendix 1 Zone 2 – Carabooda, West Pinjar, Nowergup, Zone Gnangara groundwater system zone plans Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.1 2.6.1.1 • Public water supply and bores (Figure 5): 1. It is recommended that Public water supply Public water o Zone 2 borefi elds: independent artesian any previously identifi ed management supply (Yarragadee) – only one active bore, although groundwater source options a number are on the eastern boundary in be re-evaluated in the light adjoining subareas of updated groundwater o 2007–08 borefi eld abstraction was 6 GL from allocation plans. Yarragadee aquifer.
2.6.2 2.6.2.1 • The existing land uses are refl ected in the zones It is recommended that: Urbanisation and The future and reserves of the Metropolitan Region Scheme, 2. a subregional structure plan for commercial use of east but in GSS Zone 2 the land use will change East Wanneroo be prepared, Wanneroo: signifi cantly with the changes proposed in The which is in accordance with Land use future of east Wanneroo: Land use and water the recommendations of The and water management in the context of Network City and future of east Wanneroo: Land management subsequent amendment to the Metropolitan use and water management in the Region Scheme in the context of Network context of • The future of east Wanneroo: Land use and City prepared in 2007 and Network City water management in the context of Network the fi ndings of theGnangara City integrates land use planning and future sustainability strategy. development with water resource planning 3. a net density of residential objectives, the allocation of land for horticultural development of at least 20 uses and the protection of access to basic raw dwellings per hectare be materials and the lakes for the benefi t of the achieved to ensure that whole community. (Refer to section 3.5.1 of the there is enough stormwater Situation statement) to augment groundwater • A subregional structure plan is currently levels once it is added to the being prepared for the development of this Superfi cial aquifer through zone, generally in accordance with the land soakwells and infi ltration use concept plan. The GSS fi ndings and basins. recommendations will be incorporated into the structure plan
23 Zone 2 – Carabooda, West Pinjar, Nowergup, Gnangara Sustainability Strategy Appendix 1 Zone Lake Pinjar, Neerabup, Carramar, Mariginiup Gnangara groundwater system zone plans and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.2.2 • The unifying theme of Network City is to integrate 4. It is recommended that Network City transport and land use in a network of activity Network City principles centres connected by activity and transport be considered in any corridors that allow for the movement of freight development within GSS Zone and people 2 subareas. These include: • Network City does not propose any signifi cant • accommodating urban growth changes to GSS Zone 2 but emphasises the primarily within the Network importance of the activity centres such as City pattern, incorporating Wanneroo and Wangara. It has identifi ed the new activity centres within need for upgraded transport links and strong the area as well as existing local employment targets centres such as Wanneroo • Network City promotes a more compact urban and Wangara linked by activity form and the development of East Wanneroo and transport corridors conforms to this principle • protecting access to raw materials • protecting fertile areas to encourage urban horticulture • protecting and improving the natural environment, open spaces and heritage by: o protecting biodiversity and ecosystem functions by retaining, connecting and managing habitat surrounding and through the city o protecting and improving waterways and air quality o protecting water supplies, both surface and groundwater.
24 Gnangara Sustainability Strategy Appendix 1 Zone 2 – Carabooda, West Pinjar, Nowergup, Zone Gnangara groundwater system zone plans Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.2.3 • The Industrial lands needs study completed It is recommended that: Requirement in June 2008 identifi ed the need for additional 5. the south-west corner of West for employment generating land of up to 3100 Gnangara (corner of Neaves employment ha by 2030 in the Perth–Peel Region, with and Pinjar Roads) in Zone generating approximately 730 ha required in the north- 1 that has been cleared of land west corridor. The second stage of this study is pines and has good access to currently underway and will examine potential employment, transportation industrial sites throughout the Perth–Peel Region and infrastructure be including GSS Zone 2 considered for its potential to • Part of this demand can be met from the accommodate an expansion Neerabup Industrial Park but the provision of of the Neerabup industrial area additional employment generating land within the for employment generating corridor will be critical to the ability of the corridor uses. The area may need to to achieve long-term employment self suffi ciency be excised from the Priority 1 targets and avoid ineffi cient and unsustainable Water source protection area transportation patterns developing classifi cation. • The existing Neerabup industrial area covers a 6. an area in the southern portion total of 1020 ha. There are signifi cant constraints of the West Pinjar subarea on the use of this land however, because: also be investigated for the o 350 ha is currently occupied and quarried expansion of the Neerabup by Cockburn Cement and will only become industrial area. available in 30 to 50 years 7. the excision and sale of state o 120 ha is being mined for sand and will not forest for development be available for 15 to 20 years considered as a potential o 80 ha is a priority water extraction area funding source for the cost o 107 ha is identifi ed by Bush Forever for of re-establishing native bushland protection vegetation in state forest o 28 ha is currently developed. and other environmental In summary, the land available for development maintenance. within this zone is only 336 ha at present, which means there is a considerable need for additional industrial land in the north-west sector. Of this: o 50 ha is currently being developed by LandCorp o 15 ha contains a laminated veneer lumber plant and additional land is reserved for a future bioenergy plant. • Intensive employment activities in proximity to employment sources are vital to achieving sustainable urban forms and transportation networks • Employment self-suffi ciency is currently 38% for the north-west corridor. To meet an employment self-suffi ciency target of 72%, as adopted by the North-West Corridor Coordination Committee, approximately 95 000 jobs are required immediately
25 Zone 2 – Carabooda, West Pinjar, Nowergup, Gnangara Sustainability Strategy Appendix 1 Zone Lake Pinjar, Neerabup, Carramar, Mariginiup Gnangara groundwater system zone plans and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.2.4 • A ready supply of basic raw materials close It is recommended that: Extraction to established and developing parts of the 8. basic raw materials within of basic raw Metropolitan region is essential to keep land Zone 2 be extracted to meet materials development costs down and contribute to the high demand for sand and affordable housing. Priority resource locations limestone in the Perth–Peel and key extraction areas as defi ned inState region. planning policy 2.4 Basic raw materials July 9. in order to extract basic 2000 are shown in Figure 3.11 of the Situation raw materials without statement compromising future long-term • There are basic raw materials (limestone and development for urban and sand) located in Zone 2. These should be other purposes, sequential protected for use and the land should eventually land use planning should be be rehabilitated, once extraction is completed, for undertaken to make sure that its long-term use in ways appropriate to the GSS extraction and rehabilitation and the Metropolitan Region Scheme can take place in a controlled way. 10. the availability of suitable road access be assessed. 11. e x t r a c t i o n o p e r a t i o n s b e planned and managed to avoid confl icts with adjacent land use. 12. planning for basic raw material utilisation comply with recovery plans for the threatened ecological community (Limestone ridges SCP 26a) and the limestone threatened species (Eucalyptus argutifolia).
2.6.2.5 • Initial transport modelling undertaken for the It is recommended that: Requirement North-West corridor structure plan indicates a 13. the GSS take into account for transport need to upgrade Gnangara Road and Neaves the need for major transport corridors Road to four lanes which will provide adequate corridors and that the linkages between the north-west and north-east alignment of these be corridors incorporated into appropriate • The modelling also identifi ed the need for the plans as detailed alignment construction of a new road linking Flynn Drive studies are completed by the with Alexander Drive which will alleviate traffi c Main Roads Department. congestion on Wanneroo Road and the Mitchell 14. consideration be given to Freeway aligning transport corridors outside of the current Priority 1 Underground Water Pollution Control Area (UWPCA) (i.e. the alignment of the proposed road linking Flynn Drive and Alexander Drive). Where this cannot be achieved, measures must be undertaken to properly mitigate this risk.
26 Gnangara Sustainability Strategy Appendix 1 Zone 2 – Carabooda, West Pinjar, Nowergup, Zone Gnangara groundwater system zone plans Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.3 Land use 2.6.3.1 • Horticulture in Wanneroo is viewed as important It is recommended that: management Horticulture not only for its fresh food, health and employment 15. the current Carabooda and benefi ts but also for the sense of place agriculture Nowergup subareas be provides. Challenges for the area include: retained for horticulture and o the over-allocation of groundwater resources retained as rural zoning in the o the recommendation that half the current Metropolitan Region Scheme Wanneroo production area be converted to (approximately 3500 ha). urban use 16. approximately 1100 ha of o many horticulturalists expect their land to be Crown land adjacent to urbanised at some stage to provide a capital the Carabooda-Nowergup gain to enable them to retire or to reinvest in subareas be retained for businesses further from the urban fringe. potential agriculture and • Horticulturalists will not invest in effi cient irrigation related industry use, including systems if they cannot see long-term land and horticulture production. This water security area includes approximately • It is estimated that approximately 2000 ha of 800 ha of pine plantation. cultivated land close to Perth will be needed Conversion of new land to in 40 years time to secure a supply of ‘fresh’ horticultural use is dependent vegetables for the Perth market to meet the upon an additional water demands of an increased population. To retain source being available. 2000 ha in cultivation, it was envisaged that a 17. all users be encouraged to land parcel of approximately 3000 ha be retained adopt water and nutrient for potential agriculture and related industry use, effi ciencies through the use of including horticulture. This area does not fall licenses and other tools such within the Priority 1 UWPCA boundary as metering, education and • The future of east Wanneroo: Land use and incentives. water management in the context of Network 18. horticultural practices which City (WAPC August 2007) identifi ed a Proposed use water and nutrient best Future Rural & Agricultural Precinct (measuring practices and alternate 2103 ha), which was to be set aside for both production methods such as horticultural and other rural and agricultural uses. hydroponics be encouraged. The proposed precinct included approximately 19. total private licensed 1100 ha of Crown land, approximately 800 ha of abstraction should be reduced which is currently under state forest. The balance by around 20 per cent. is privately owned and some of this land is 20. a land swap or purchase of the currently used for horticulture northern ‘tip’ of the Carabooda • Additional land in the Carabooda and Nowergup subarea for an area of state areas is in private ownership (measuring 2452 forest be considered to reduce ha) and are currently zoned Rural. Approximately the impact of groundwater 650 ha of this existing Rural zoned land is used abstraction on the surrounding for horticultural purposes, and the balance of woodlands and Yanchep approximately 1800 ha is used for a range of caves. rural and agricultural uses. This land does not fall 21. the provision of recycled water within the Priority 1 UWPCA boundary for a horticulture precinct for • Conversion of new land to horticultural use is Carabooda be re-examined in dependent upon an additional water source being the future. available. Recycled water is viewed as a potential water supply option for the Carabooda area once suffi cient volumes are available
27 Zone 2 – Carabooda, West Pinjar, Nowergup, Gnangara Sustainability Strategy Appendix 1 Zone Lake Pinjar, Neerabup, Carramar, Mariginiup Gnangara groundwater system zone plans and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.3.2. • Poultry farming for eggs and ‘grow out’ facilities 22. It is recommended that Poultry for meat are declining north of Perth with larger provision be made for farming producers moving further out to Gingin and intensifi cation of industrial and Bunbury agricultural land use activities • Three to four ‘grow out’ facilities remain in the (for example, food processing area immediately north of Perth which supply a facilities). processing plant in Osborne Park • It is anticipated that the processing plant will relocate in the next few years and ‘grow out’ facilities will transfer to be closer to the processing facility • State planning policy 4.3 Poultry farms policy (WAPC 1998) outlines the land use planning and water quality issues that should be addressed in relation to poultry farming
2.6.3.3 • The Pinjar off road vehicle area (ORVA) is located It is recommended that: Recreation on 250 ha of state forest on the corner of Old 23. the City of Wanneroo Yanchep Road and Wattle Avenue and has a determine a location for a capacity of about 1000 riders a day. It provides a regional open space facility, legal opportunity for riders of non-road registered providing that an adequate motorcycles and quad bikes, and people who do water supply for irrigation not hold a driver’s licence, to ride on public land can be identifi ed and that • A recent review of the Gnangara and Pinjar water effi cient measures are ORVA for the Department of Environment and adopted. Conservation has recommended their retention 24. the Pinjar ORVA be retained on and upgrade for the safety of riders or near its current location and • The City of Wanneroo requires approximately 40 its management upgraded to ha for a regional open space reserve for primarily address safety and behaviour active recreation issues.
28 Gnangara Sustainability Strategy Appendix 1 Zone 2 – Carabooda, West Pinjar, Nowergup, Zone Gnangara groundwater system zone plans Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.3.4 • The quality, variety and accessibility of public It is recommended that: Water open space is important for the physical, mental 25. all new developments sensitive and social wellbeing of communities. Currently 39 (including public open space) urban design GL of water is used to irrigate public open space adopt water sensitive design and public across the GSS study area principles which incorporate open space • Approximately 0.35 GL is used to irrigate public the sustainable management open space in this zone (see Figure 4) and integration of stormwater, wastewater and groundwater into urban design. 26. public open space be managed with greater water and nutrient use effi ciencies by encouraging local government to: • monitor water use • maintain water effi cient irrigation systems • develop best practice systems • redevelop public open space using hydrozones and ecozones. 27. annual allocations of groundwater to local government be based on seasonally-recorded groundwater levels, with the feasibility of increased allocations in return for increased recharge using stormwater and treated wastewater.
2.6.3.5 • Acid sulphate soils and groundwater acidifi cation It is recommended that: Acid in the Mariginiup, Lake Pinjar and Lake Gnangara 28. further research be carried sulphate subareas is generally high to moderate where out to better understand soils associated with grey sands with low buffering the potential acid sulphate capacity and the large number of seasonal soil implications on the wetlands Spearwood–Bassendean dune • Acidifi cation of Lake Jandabup is contained by interface from increased urban relatively expensive augmentation using nearby and transport development groundwater and this becomes less viable as and the associated impacts to regional groundwater levels fall wetlands. • The potential for acid sulphate problems in 29. Management of acid sulphate non-wetland soils in the Carabooda, Nowergup, soils and improvement of the Neerabup, West Pinjar and Carramar subareas is acid sulphate soils risk map generally considered low, mainly due to the high be undertaken by utilising buffering capacity of the coastal dune sands. information and studies However, wetland sediments are considered a from the impacts that have moderate to high acid sulphate soils risk occurred at Lake Gnangara.
29 Zone 2 – Carabooda, West Pinjar, Nowergup, Gnangara Sustainability Strategy Appendix 1 Zone Lake Pinjar, Neerabup, Carramar, Mariginiup Gnangara groundwater system zone plans and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.4 2.6.4.1 • This zone has four under-represented vegetation It is recommended that: Biodiversity Ecological complexes and several signifi cant wetlands. 30. proposed ecological linkages linkages The GSS has identifi ed ecological linkages that be incorporated into structure attempt to protect intact remnant vegetation, plans. wetlands and Bush Forever sites while 31. two ecological linkages in rehabilitating linkages with surrounding subareas West Pinjar be re-established, • The remnant vegetation has been heavily cleared on state forest, once pines are for agricultural, pine plantation, urban and cleared. industrial development in this zone. Remnants 32. the purchase by the remaining are small and highly fragmented and Western Australian Planning a number have been identifi ed as regionally Commission of Bush Forever signifi cant by Bush Forever. Larger remnants are areas in Lake Pinjar subarea at risk of becoming highly fragmented due to be consolidated. continued development pressure • Several under-represented vegetation complexes in formal conservation estate occur. Identifi ed priorities for additional protection include vegetation complexes on yellow Spearwood soil (Cottesloe Central/South and Karrakatta Central/ South) and wetland Herdsman Complex. Wetland Pinjar vegetation complex lies largely within Lake Pinjar and Mariginiup subareas and are identifi ed as Bush Forever sites • Bush Forever (WAPC 2000) identifi ed four regional ecological linkages and the Perth Biodiversity project (WALGA 2004) an additional six regional linkages across this zone. The GSS has identifi ed 14 priority conceptual links within Zone 2, which will provide links to large areas of bushland in Neerabup and Yanchep national parks, Gnangara Park, Whiteman Park, lakes and to the coast • It is proposed that the remnant bushland in the West Pinjar subarea be connected by two ecological linkages of over 837 ha once the area has been cleared of pines. Only 21% of the linkages require rehabilitation
30 Gnangara Sustainability Strategy Appendix 1 Zone 2 – Carabooda, West Pinjar, Nowergup, Zone Gnangara groundwater system zone plans Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.4.2 • There are two threatened ecological communities It is recommended that: Threatened in this zone. These are: 33. threatened fl ora, fauna and fl o r a , o SCP 20a Banksia attenuata, where the ecological communities be fauna and community is threatened by lowering of managed in accordance with ecological the groundwater level and reduction in soil the Wildlife Conservation Act communities moisture recharge due to climate change 1950 (WA), and the relevant o Limestone ridges SCP 26a where the recovery plans for threatened community is threatened by clearing for and priority species and mining operations and by too frequent fi re with ecological communities. subsequent weed invasion 34. where applicable, threatened • There are seven recorded occurrences of the fl ora, fauna and ecological declared rare fl ora species Eucalyptus argutifolia communities be managed on limestone ridges in this zone and seven in accordance with the populations of priority fl ora have been recorded. Environment Protection and The impacts of hydrological changes on the Biodiversity Conservation Act priority fl ora are largely unknown 1999 (Cwlth). • Priority listed mammals are known to occur 35. confl ict between protection within this zone. The wetlands within this zone of the Limestone ridges (SCP provide important breeding sites for remnant frog 26a TEC), the declared rare populations fl ora species Eucalyptus • The endangered Carnaby’s black-cockatoo argutifolia on limestone ridges (Calyptorhynchus latirostris) occurs throughout and limestone mining be the zone. Both the Pinjar pine plantation and the negotiated on a regional scale. surrounding remnant native Banksia vegetation represent important foraging habitat for this species
31 Zone 2 – Carabooda, West Pinjar, Nowergup, Gnangara Sustainability Strategy Appendix 1 Zone Lake Pinjar, Neerabup, Carramar, Mariginiup Gnangara groundwater system zone plans and Lake Gnangara subareas July 2009
2.6 Recommendations to address water and land management issues in Zone 2
Management Issue Explanation Recommendations consideration
2.6.4.3 • There are few effective options available for It is recommended that: Wetlands managing some wetlands under drying climate 36. wetland biodiversity values and scenarios where there is either a long lag time and wetland complexes be groundwater in groundwater recovery or no recovery, and/or identifi ed and prioritised. dependent where there is a severe impact from acid sulphate 37. remaining wetlands and ecosystems soils groundwater dependent • This zone contains signifi cant high quality ecosystems be monitored and wetlands (damplands, sumplands and lakes) protected from development. and other groundwater dependent ecosystems, 38. it be determined whether including seven ministerial criteria sites there are any wetlands or • The Pinjar wetland vegetation complex occurs groundwater dependent only within the GSS study area and lies largely ecosystems that should be within Lake Pinjar and Mariginiup subareas incorporated into any future • Although 98% of Lake Pinjar subarea is protected review of ministerial criteria by Bush Forever and the nominated additions to sites. Bush Forever, the Western Australian Planning 39. the feasibility of maintaining Commission has purchased just over 50% of or recovering wetlands these sites. It is important to consolidate these affected by water decline and purchases not only through further acquisitions acid sulphate soils by using but also by vesting the land in the Department of stormwater and wastewater Environment and Conservation managed estate streams be determined. 40. further analyses of risks and cost-benefi ts of management options be undertaken. 41. an assessment be undertaken of the relative effectiveness of the continued augmentation of wetlands (Lake Jandabup, Lake Nowergup) in a drying climate compared with other alternative uses of groundwater. (A local area model is being developed for Lake Nowergup). 42. an investigation be undertaken into the importance of wetlands for waterfowl and migratory birds.
32 Gnangara Sustainability Strategy Appendix 1 Zone 2 – Carabooda, West Pinjar, Nowergup, Zone Gnangara groundwater system zone plans Lake Pinjar, Neerabup, Carramar, Mariginiup and Lake Gnangara subareas July 2009
Figure 5 Zone 2 public water supply borefi elds
33 Zone 3 plan – Bullsbrook, Ellenbrook Town and West Swan subareas Zone 3 Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
3.1 Overview Population in 2006
The zone is largely rural and semi-rural, with West Swan – 6344, Ellenbrook Town – 12 530, increased urbanisation occurring in Ellenbrook and Bullsbrook – 834 West Swan. Signifi cant growth is occurring within the City of Swan and development will be guided by Land form (surface geology) the draft Swan urban growth corridor subregional structure plan 2008, the Ellenbrook place plan 2004 Bassendean Dune, Guildford Clay, lacustrine and the draft Bullsbrook townsite and rural strategy (peat, peaty sands) 2008, the Metropolitan Region Scheme and Network City. Social values include tourism and recreation, Wetlands especially in the Swan Valley. Conservation wetlands exist across the area, Several Bush Forever sites are located within Zone including Edgecombe seepage, Egerton Spring, 3, and these provide important core areas for the Lake Yakine, Kings Spring, Ellenbrook Swamp, development of ecological linkages. Twin Swamps and Ellen Brook
Indigenous sites of signifi cance The Swan River and Ellen Brook form the southern and eastern boundary for Zone 3 with urban and 56, including Ellen Brook, Bennett Brook camp industrial area to the south-west, Whiteman Park area, Monger Brook, Marshalls Paddock, South and Banksia woodland on state forest to the west Bullsbrook and rural holdings to the north.
Percentage of Subarea Land area Ha total GSS area 3.2 Allocation status of Zone 3
West Swan 4211 2.0 The GSS zone and subarea boundaries differ from the current water allocation management area Ellenbrook 4867 2.3 boundaries used by the Department of Water. Town The Gnangara groundwater area is proclaimed in accordance with s.26B of the Rights in Water and Bullsbrook 6750 3.1 Irrigation Act 1914 (Figure 15). Local governments As of December 2008 the licensed groundwater Town of Bassendean, Shire of Chittering, City of allocation status for gazetted groundwater subareas Swan which fall within GSS Zone 3, is as follows (see Figure 6):
34 Gnangara Sustainability Strategy Appendix 1 Zone 3 – Bullsbrook, Ellenbrook Town Zone Gnangara groundwater system zone plans and West Swan subareas
July 2009
• The draft Gnangara groundwater areas In Zone 3 the GSS recommends that abstraction management plan (2008) set allocation limits for horticulture and public open space be reduced which indicate that groundwater subareas through increased water use effi ciencies with in the Superfi cial aquifer are 88 to 161 per licensed amounts being reduced by 20 per cent on cent allocated under the current climate and average, or to the allocation limit, as appropriate. current land and water use. The GSS also recommends that in the future water be allocated as a periodic share of available water • The current management strategy in over which will enable allocations to refl ect the inter- allocated areas is to cap use (so no new annual and seasonal availability of water. licences are issued), reduce use through effi ciency and recover water where licensing In addition, the GSS recommends that treated processes allow. wastewater be increasingly used for augmenting • A small volume of water is available from the groundwater levels and direct use where available State Forest groundwater subarea. and suitable (e.g. vines on suitable soils). Depending on the amount of reuse and future climate, • There is no additional water available from groundwater levels may be stabilised in parts of the the Leederville or Yarragadee aquifers in zone under this regime. Zone 3. In addition to the licensed use of water outlined Predicted continued reduction in recharge from above, it is estimated that approximately 0.96 rainfall will reduce water availability in future years. gigalitres of water is abstracted from the Superfi cial Changes in current land use may alter this trend. aquifer for unlicensed use. Unlicensed use includes taking of water for stock and domestic purposes in addition to use for domestic garden bores.
Figure 6 Zone 3 2008 licensed groundwater allocation – 16.6 gigalitres
35 Zone 3 – Bullsbrook, Ellenbrook Town Gnangara Sustainability Strategy Appendix 1 Zone and West Swan subareas Gnangara groundwater system zone plans
July 2009
3.3 Issues • allow the Swan urban growth corridor and Ellenbrook townsite to expand in accordance with approved structure plans The most important issues that need to be addressed within Zone 3: • restore aquifer balance by increasing recharge and reducing discharge • the area covered by the Swan Valley Planning Act 1995 does not have the • reduce nitrogen and phosphorus leakage groundwater resource to support its into the Swan River potential horticultural use • support the implementation of the • the existence of threatened ecological Ellenbrook/Chittering landcare plan (Swan communities in both Ellenbrook and River Trust) Bullsbrook • protect threatened ecological community • the critically endangered Western Swamp sites, including mound springs Tortoise habitat is under threat from urban • protect the Western Swamp Tortoise by development and climate change protecting its habitat and the water balance • the management of acid sulphate soils • protect Bush Forever sites and remnant • Bullsbrook and Ellenbrook have signifi cantly vegetation on the biologically unique and over-allocated water resources with further highly cleared eastern side of the Swan pressure coming from increased urban coastal plain development • prevent the formation of acid sulphate soils • the signifi cant growth which is occurring and protect groundwater quality within this zone. Development will be • maintain opportunities for rural lifestyle guided by the draft Swan urban growth corridor subregional structure plan 2008, • manage winter fl ood mitigation the Ellenbrook place plan 2004, the draft Bullsbrook townsite and rural strategy • identify and protect Indigenous and 2008, the Metropolitan Region Scheme and European heritage (e.g. associated with Network City tributaries of Swan River)
• the urbanisation of areas within this zone • support regional tourism and recreation will generate increasing amounts of climate • maintain and enhance Whiteman Park by independent wastewater streams that may extending it to include rural zoned land to be directly or indirectly used locally or in the the west of Beechboro Road North neighbouring Chittering Valley • mitigate the spread and intensifi cation of • the existence and protection of 837 ha of Phytophthora cinnamomi dieback bushland identifi ed as regionally signifi cant land currently zoned rural to the west of • rehabilitate degraded sites Beechboro Road North and Whiteman Park. • support mineral extraction (sandmining) 3.4 Objectives • support the Swan Valley Planning Act 1995
The objectives of the Gnangara sustainability • control European House Borer strategy for Zone 3 are to: • manage salt water interface linked to abstraction (West Swan). • protect Priority 3 Water source protection areas and public water supply infrastructure and water resources
36 Gnangara Sustainability Strategy Appendix 1 Zone 3 – Bullsbrook, Ellenbrook Town Zone Gnangara groundwater system zone plans and West Swan subareas
July 2009
3.5 Recommendations for the whole of Zone 3 with associated benefi ts and risks
Recommendation Benefi ts Risks
1. It is recommended that • Protection of social, heritage and • Reduced economic opportunity for employment the GSS support the Swan economic values associated with diversity and/or alternative future unknown land Valley Planning Act 1995 to tourism, horticulture, viticulture and use activities and urban development protect tourism, horticulture, rural amenity • Pressure on limited groundwater resources viticulture and rural amenity. • Extremely strong community support • Potential for saltwater intrusion from Swan River
2. It is recommended that • Retains social amenity and sense of • Reduces opportunity to develop employment Bullsbrook subarea place associated with subarea generating land uses be retained as rural in • Reduced need for infrastructure accordance with the draft associated with urban development Bullsbrook townsite and rural strategy 2008.
3. It is recommended that: • Traditional grape growing and • Lack of government willingness to mandate water • horticulture be retained in horticultural areas retained and nutrient effi ciency practices current horticultural sectors • Over allocation redressed and aquifer • Uncertainty over water security may affect • water be allocated refl ecting managed sustainably growers’ capacity and willingness to invest in a periodic share of available • Reduced impact of nutrients and water and nutrient effi ciency practices water water allocation on downstream • Lack of a mechanism to update and mandate • horticultural practices which values water and nutrient effi ciency practices as use water and nutrient best • Reduced water allocations motivates techniques are improved practices and alternate investment in water effi ciency production methods such as practices and better use of limited hydroponics be encouraged. resource
4. It is recommended that • Reduced demand on groundwater • Contamination of groundwater investigations be conducted resources • Increased costs and energy use due to disparate into: • Improved social amenity for local water treatment plants • diverting stormwater from residents (irrigated public open • Less water available for Beenyup Wastewater Ellen Brook, thus improving space, viticulture, horticulture) Treatment Plant stream and estuarine water • Opportunities for private supply of • Obtaining health regulator support for sewer qualities water and trading mining • sewer mining, to enable • Reduced fl ow of nutrients into Ellen • Public not willing to pay for treated wastewater wastewater to be reused Brook while groundwater is still freely available close to the area that it is • Reduced costs and carbon • Reduced surface water fl ows may interfere with generated, thus reducing emissions from avoided pumping environmental values of Ellen Brook pumping costs.
37 Zone 3 – Bullsbrook, Ellenbrook Town Gnangara Sustainability Strategy Appendix 1 Zone and West Swan subareas Gnangara groundwater system zone plans
July 2009
3.5 Recommendations for the whole of Zone 3 with associated benefi ts and risks
Recommendation Benefi ts Risks
5. It is recommended that • Increased biodiversity and increased • High cost of land purchase, vegetation re- regional ecological linkages resilience of ecosystems to climate establishment and weed control between Gnangara Park, change • High ongoing maintenance costs and the need Whiteman Park, the Darling • Creation of social amenity and for a decision as to who manages these linkages Scarp and the Swan River be landscape values • Precludes alternative land uses established. • Enhanced landscape connection for • Decreases ability to maximise recharge Whiteman Park • Strong community support • Linkage along the river, brook and streams will help strip nutrients and protect aquatic fauna • Increased opportunity for passive and active recreation with associated benefi ts to the community
6. It is recommended that • Protects biodiversity Whiteman Park and land • Enhanced landscape connection for to the north of Ellenbrook Whiteman Park townsite be retained as • Strong community support ‘parks and recreation’ in • Maintains opportunities for passive the Metropolitan Region and active recreation with associated Scheme. benefi ts to the community • Maintains social amenity and landscape values • Maintains Whiteman Park’s value as an important tourism destination
7. Rural land to the west of • Supported by all the relevant state Beechboro Road North government agencies be amalgamated with • Consultation associated with Whiteman Park and reserved amendment of Metropolitan Region as ‘parks and recreation’ Scheme 1161/141 provided evidence in the Metropolitan Region of community support Scheme. • Overall improvement to Whiteman Park • Increased opportunity for passive and active recreation with associated benefi ts to the community • Social amenity and landscape values improved • Protection of 837 ha of bushland identifi ed as regionally signifi cant in Bush Forever 2000
38 Gnangara Sustainability Strategy Appendix 1 Zone 3 – Bullsbrook, Ellenbrook Town Zone Gnangara groundwater system zone plans and West Swan subareas
July 2009
3.6 Recommendations to address water and land management issues in Zone 3
Management Issue Explanation Recommendations consideration
3.6.1 3.6.1.1 • Public water supply and bores (Figure 7): It is recommended that: Public water supply Public water o Zone 3 borefi elds: Lexia and 1. the effects of public water supply management supply Mirrabooka relative to other factors on groundwater o 2007–08 borefi eld abstraction was 1.5 dependent ecosystems and Bennett GL Abstraction by aquifer: Superfi cial Brook be investigated. 0.62 GL, Mirrabooka 0.35 GL and 2. the GSS support the winter trial Leederville 0.56 GL pumping regimes to determine the effects on groundwater dependent ecosystems.
3.6.1.2 • Using locally treated wastewater It is recommended that: Stormwater generated in the newly urbanised areas 3. an investigation be carried out into and recycled for augmenting groundwater levels diverting stormwater in order to water and for direct reuse would reduce the maintain groundwater levels for need to pump water to Beenyup and wetlands and use in Swan Valley eventually Alkimos wastewater treatment viticulture and horticulture. plants while avoiding crossing Priority 1 4. freehold pasture land continue to be Water source protection areas managed to maximise recharge. 5. an investigation be carried out into the opportunities for using locally treated wastewater generated in the newly urbanised areas for augmenting groundwater levels and for direct reuse. 6. an investigation be carried out into the local wastewater treatment trials in the Swan Valley.
3.6.2 3.6.2.1 • Zone 3 contains residential and It is recommended that: Urbanisation and Urban commercial development in Ellenbrook 7. Ellenbrook townsite continue to expand commercial use development Town and Bullsbrook subareas and will as planned in the Ellenbrook place plan contain considerable urban development 2004 to become an important regional in West Swan in the future as refl ected centre providing signifi cant facilities and in the Draft Swan urban growth corridor services for the north-east corridor. subregional structure plan 2008. The 8. development to the south of Ellenbrook remainder of the zone is generally used townsite occur in accordance with for horticulture and agriculture the draft Swan urban growth corridor • Ellenbrook townsite will continue to structure plan 2008. expand as planned in the Ellenbrook 9. no further urban development occur place plan 2004 and will become an north of Ellenbrook townsite and the important regional centre providing Bullsbrook subarea be retained as a signifi cant facilities and services for the rural setting. north-east corridor 10. all new developments adopt • In the long term, Bullsbrook townsite water sensitive design principles may expand to 30 000 but this which incorporate the sustainable development would occur just to the management and integration east of the Gnangara study area of stormwater, wastewater and groundwater supply into urban design.
39 Zone 3 – Bullsbrook, Ellenbrook Town Gnangara Sustainability Strategy Appendix 1 Zone and West Swan subareas Gnangara groundwater system zone plans
July 2009
3.6 Recommendations to address water and land management issues in Zone 3
Management Issue Explanation Recommendations consideration
3.6.2.2 • A ready supply of basic raw materials It is recommended that: Extraction close to established and developing 11. basic raw materials within Zone 3 be of basic raw parts of the Metropolitan region is extracted to meet the high demand for materials essential to keep land development sand in the Perth–Peel region. costs down and contribute to affordable 12. in order to extract basic raw materials housing. Priority resource locations and without compromising future long- key extraction areas as defi ned inState term development for urban and other planning policy 2.4 Basic raw materials purposes, sequential land use planning July 2000 are shown in Figure 3.11 of the should be undertaken to make sure that Situation statement extraction and rehabilitation can take • There are basic raw materials (clay and place in a controlled way. sand) located in Zone 3. These should 13. the availability of suitable road access be protected for use and the land be assessed. should eventually be rehabilitated, once 14. extraction operations be staged to extraction is completed, for its long-term avoid confl icts with adjacent land use. use in ways appropriate to the GSS and 15. preference be given to mining on Metropolitan Region Scheme already cleared lands and wherever • The supply of sand resources is possible mining tenements exclude diminishing and becoming increasingly remnant vegetation areas. diffi cult to gain access to and extract
3.6.3 3.6.3.1 • The horticulture precinct has been It is recommended that investigations be Land use Horticulture protected by legislation that limits carried out into: management in the Swan subdivision and other land use options 16. the availability of irrigation water, Valley in order to protect the table grape and including treated wastewater. wine grape industries 17. local wastewater treatment trials in the • Options for subdivision have been Swan Valley. restricted, labour options are limited, land rates are high and land use confl icts are increasingly encountered • Mixed horticulture and tourism land uses may help to overcome some of these diffi culties • Water availability restricts expansion of horticulture in the Swan Valley • Treated wastewater is used for vines in other areas of the state (for example at Mt Barker) and depleted confi ned and unconfi ned aquifers are available for winter storage • There is additional water demand for horticulture in the nearby Chittering Valley
40 Gnangara Sustainability Strategy Appendix 1 Zone 3 – Bullsbrook, Ellenbrook Town Zone Gnangara groundwater system zone plans and West Swan subareas
July 2009
3.6 Recommendations to address water and land management issues in Zone 3
Management Issue Explanation Recommendations consideration
3.5.3.2 • The general objectives of the Swan 18. It is recommended that the GSS Swan Valley Valley Planning Act 1995 are the support the Swan Valley Planning Act Planning Act encouragement of the traditional 1995 and the protection of the sense of 1995 agricultural and other productive place values associated with tourism, uses of the area that complement its horticulture, viticulture and rural rural character, the protection of the amenity. environment and the character of the area, the reduction of nutrient levels in the Swan River and the promotion of tourism that complements the rural character of the Swan Valley
3.6.3.3 • There is a need to reduce nutrient fl ows It is recommended that: Water and into the Swan River from this zone 19. the horticulture sector be retained for nutrient • Maintaining and/or increasing production horticulture. effi cient can only be achieved through water use 20. all users be encouraged to adopt water horticultural effi ciencies because the zone is fully and nutrient effi ciencies through the practices allocated use of licences and other tools such as metering, education and incentives. 21. horticultural practices which use water and nutrient best practices and alternate production methods such as hydroponics be encouraged.
3.6.3.4 • In Zone 3, broad scale mapping has 22. It is recommended that mapping, Acid sulphate identifi ed the subareas in Zone 3 as monitoring and investigation of potential soils having moderate to low risk of acid acid sulphate soils be undertaken. This sulphate soils. However, local dewatering should include the impact of dewatering is thought to have caused acid sulphate on the eastern side of the Swan coastal soil problems in the Ellenbrook subarea plain. • Detailed information on acid sulphate soil distribution in Bullsbrook is lacking
3.6.3.5 • Metropolitan Region Scheme It is recommended that: Regional Amendment No. 1161/141 proposes 23. consideration of a band of replacement open space that the land to the west of Beechboro trees be planted along the eastern and Road North currently zoned rural in southern edges of the Gnangara pine the Metropolitan Region Scheme be plantation post-pines, to retain visual reserved as parks and recreation and amenity for Ellenbrook residents. amalgamated with Whiteman Park. 24. the extension of Whiteman Park This proposal is strongly supported includes land zoned rural west of by state government agencies and the Beechboro Road North. community 25. protection be given to the 837 ha of bushland identifi ed in Bush Forever, 2000 as regionally signifi cant. 26. the Priority 1 Water source protection area in the Metropolitan Region Scheme be retained.
41 Zone 3 – Bullsbrook, Ellenbrook Town Gnangara Sustainability Strategy Appendix 1 Zone and West Swan subareas Gnangara groundwater system zone plans
July 2009
3.6 Recommendations to address water and land management issues in Zone 3
Management Issue Explanation Recommendations consideration
3.6.3.6 • The quality, variety and accessibility of It is recommended that: Public open public open space is important for the 27. public open space be managed space physical, mental and social wellbeing, of with greater water and nutrient use communities. Currently 39 GL of water effi ciencies by encouraging local is used to irrigate public open space government to: across the GSS study area • monitor water use • Approximately 1.46 GL is used to irrigate • maintain water effi cient irrigation public open space in this zone (see systems Figure 6) • develop best practice systems • redevelop public open space using hydrozones and ecozones. 28. the possibility of using the south-east corner of the Gnangara pine plantation in Zone 1 or another degraded area, including Bullsbrook, be evaluated for regional recreation facilities by the City of Swan. The availability of irrigation water, including treated wastewater, needs to be a major part of the investigation.
3.6.4 3.6.4.1 • Over 95% of the eastern side of the It is recommended that: Biodiversity Ecological Swan coastal plain has been cleared 29. additional protection be given as a linkages of native vegetation for rural and more priority to vegetation complexes which recently urban development have less than 30% remaining on the • Important remnants are protected in eastern side of the Swan coastal plain. the Department of Environment and 30. the remaining remnants be incorporated Conservation Estate (including Twin where possible into ecological linkages Swamps, Ellen Brook and Neaves nature and these linkages be part of structure reserves) and others have been identifi ed plans and the Metropolitan Region as regionally signifi cant through Bush Scheme. Forever 31. rehabilitation and revegetation of • Two vegetation complexes occurring fragmented and degraded remnants be in this zone have less than 10% a priority. remaining across the Swan coastal plain 32. the GSS support ecological linkages (Beermullah and Guildford complexes) along the banks of the Swan River, Ellen and a further four have less than 30%. Brook and Bennett Brook to protect These vegetation complexes are a riverine vegetation and aquatic fauna. priority for additional protection and inclusion into ecological linkages • Bush Forever identifi ed four regional ecological linkages and the Perth Biodiversity project an additional three regional linkages across this zone. The GSS endorses six of these priority ecological linkages to provide a network to large areas of protected bushland in Whiteman Park and Gnangara Park to the west and the Darling Scarp to the east • Local ecological linkages have also been identifi ed by the City of Swan
42 Gnangara Sustainability Strategy Appendix 1 Zone 3 – Bullsbrook, Ellenbrook Town Zone Gnangara groundwater system zone plans and West Swan subareas
July 2009
3.6 Recommendations to address water and land management issues in Zone 3
Management Issue Explanation Recommendations consideration
3.6.4.2 • Three threatened ecological It is recommended that: Threatened communities from the eastern side of the 33. threatened fl ora, fauna and fl o r a , Swan coastal plain are present in this ecological communities be managed fauna and zone. All are groundwater dependent in accordance with the Wildlife ecological ecosystems (Tumulus Mound Springs – Conservation Act 1950 (WA), and the communities 7 sites, Wetlands SCP 15 - two sites and relevant recovery plans for threatened Muchea Limestone – two sites) and priority species and ecological • There are 12 populations of declared communities. rare fl ora and 12 populations of priority 34. where applicable, threatened fl ora, fl ora. Many are dependent on seasonal fauna and ecological communities surface water be managed in accordance with the • The last natural Western Swamp Tortoise Environment Protection and Biodiversity populations are found only in this zone, Conservation Act 1999 (Cwlth). restricted to Ellen Brook and Twin 35. the GSS supports the Western Swamps nature reserves. The habitat Swamp Tortoise habitat environmental for this population is protected under protection policy 2002. the Western Swamp Tortoise habitat environmental protection policy 2002
3.6.4.3 • Zone 3 generally has groundwater levels It is recommended that: Wetlands close to the surface and extensive 36. remaining wetlands and groundwater and areas of winter fl ooding palusplain. Two dependent ecosystems be monitored groundwater springs are monitored ministerial criteria and protected from development. dependent sites 37. it be determined whether there ecosystems • Biodiversity values in the Bennett Brook are any wetlands or groundwater (protected within Whiteman Park), dependent ecosystems that should be Swan River and Ellen Brook linkages incorporated into any future review of could be strengthened by targeted ministerial criteria sites. rehabilitation. This would provide the added benefi t of improving surface water quality by nutrient amelioration and soil amendment
43 Zone 3 – Bullsbrook, Ellenbrook Town Gnangara Sustainability Strategy Appendix 1 Zone and West Swan subareas Gnangara groundwater system zone plans
July 2009
Figure 7 Zone 3 public water supply borefi elds
44 Zone 4 plan – Quinns Rock, Eglinton and Yanchep–Two Rocks subareas Zone 4 Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
4.1 Overview Land form (surface geology)
Zone 4 lies within the north-western corridor of the Quindalup Dunes, Spearwood Dunes, Safety Bay Metropolitan Region Scheme and includes land Sand zoned urban, urban deferred, central city area, industrial and land reserved for parks and recreation Wetlands and public purposes. The coastal setting is a major attraction for development of the corridor. No signifi cant wetlands. Beonaddy Swamp, Pipidinny Swamp, Paul’s Swamp Much of the zone lies within a Priority 3 Water source protection area to manage the risk of Indigenous sites of signifi cance contamination to drinking water sources. 33, including Mindarie Waugul, Jindalee, Mindarie The zone has social values with recreational and Burial Mound, Yanchep Beach, Karli Spring tourism facilities found throughout the Yanchep–Two Rocks subarea and associated high quality beaches. Yanchep National Park is nearby and is one of Perth’s most popular tourist attractions. 4.2 Allocation status of Zone 4
The GSS zone and subarea boundaries differ from Percentage of Subarea Land area ha the current water allocation management area total GSS area boundaries used by the Department of Water. The Gnangara groundwater area is proclaimed in Quinns Rock 5743 2.7 accordance with s.26B of the Rights in Water and Irrigation Act 1914 (Figure 15). Eglinton 2424 1.2
Yanchep–Two 6888 3.2 As of December 2008 the licensed groundwater Rocks allocation status for gazetted groundwater subareas which fall within Zone 4, is as follows (see Figure 8): Local government • The draft Gnangara groundwater areas City of Wanneroo management plan (2008) set allocation limits which indicate that groundwater Population in 2006 subareas in the Superfi cial aquifer are 93 to 97 per cent allocated under the current Quinns Rock – 39 789, Eglinton – 59, Yanchep– climate and current land and water use. This Two Rocks – 4121 includes reserves set aside for public water supply expansion as the north west corridor grows along the coast as predicted by the Metropolitan Regional Scheme.
45 Zone 4 – Quinns Rock, Eglinton Gnangara Sustainability Strategy Appendix 1 Zone and Yanchep-Two Rocks subareas Gnangara groundwater system zone plans
July 2009
• A small volume of water is available from the if abstraction for public water supply, public open Eglinton, Quinns and Yanchep groundwater space and private bores becomes excessive. subareas. In addition to the licensed use of water outlined • There is no additional water available from above, it is estimated that approximately 0.5 the Leederville or Yarragadee aquifers in gigalitres of water is abstracted from the Superfi cial Zone 4. aquifer for unlicensed use. Unlicensed use includes Predicted continued reduction in recharge from taking of water for stock and domestic purposes in rainfall will reduce water availability in future years. addition to use for domestic garden bores. Changes in current land use may alter this trend. 4.3 Issues In Zone 4 the GSS recommends that all new developments use water sensitive design principles The most important issues that need to be which incorporate the sustainable management addressed within Zone 4: and integration of stormwater, wastewater and groundwater supply into urban design. Groundwater • this part of the north-west corridor is one of levels in the zone are not predicted to fall signifi cantly the fastest growing areas of Perth and its under the GSS recommendations because of the population will signifi cantly increase during high transmissivity of the limestone aquifer and the next 20 to 30 years. The rapid growth the recharging of roof and road runoff. Care will be places considerable pressure on local needed to avert the possibility of salt water intrusion
Figure 8 Zone 4 2008 licensed groundwater allocation – 27.7 gigalitres
46 Gnangara Sustainability Strategy Appendix 1 Zone 4 – Quinns Rock, Eglinton Zone Gnangara groundwater system zone plans and Yanchep-Two Rocks subareas
July 2009
and state government to provide facilities • better manage water usage for public and services including infrastructure and open space by using shared space, water opportunities for commercial activities, conservation strategies and water reuse recreation and employment • support the North-West corridor structure • the employment self-suffi ciency target of plan with most of the zone being allocated the north-west corridor is currently 38%. to urban uses, parks and recreation and To meet an employment self-suffi ciency having multiple transport corridors and some target of 72%, as adopted by the North- ecological linkages West Corridor Coordination Committee, approximately 95 000 new jobs are required • develop activity centres connected as a high priority by activity and transport corridors in accordance with Network City • there is potential in each of the subareas for public water supply, however saltwater • retain existing horticulture (note that intrusion is a risk which will need to be horticultural uses constitute only 1% of carefully managed, especially where the overall groundwater use) aquifer is deep and the salt water wedge • develop wastewater reuse extends a long way inland • protect threatened ecological communities • the need for improved water effi ciencies and groundwater dependent ecosystems related to watering of public open space • maintain Tamala Park as a regional landfi ll • the protection of ecological linkages and the facility. Quindulup Dune landform and vegetation
• linear urban development is occurring without corresponding employment opportunities, which has signifi cant sustainability and transport impacts if not addressed urgently.
4.4 Objectives
The objectives of the Gnangara sustainability strategy for Zone 4 are to:
• investigate the potential for additional public water supply (expansion of borefi elds in the development front)
• manage salt water intrusion from the ocean
• protect the Quindalup Dune landform and it’s associated vegetation
• maximise employment opportunities (industrial, energy-related, tidal power)
• maintain Eglinton ecological linkages
• identify and develop ecological linkages along the coastal dunes and from the coast to the Neerabup and Yanchep national parks
47 Zone 4 – Quinns Rock, Eglinton Gnangara Sustainability Strategy Appendix 1 Zone and Yanchep-Two Rocks subareas Gnangara groundwater system zone plans
July 2009
4.5 Recommendations for the whole of Zone 4 with associated benefi ts and risks
Recommendation Benefi ts Risks
1. It is recommended that • Increased water security • Decreases options for managed aquifer an investigation be carried • Decreased pumping costs because replenishment using treated wastewater to out into the groundwater public water supply will be close to raise groundwater levels and protect against resource for public water demand salt water intrusion if the public water supply supplies for a growing local • Intercepts groundwater that would borefi elds are close to the coast population, including ways of fl ow to the ocean • Possible saltwater intrusion into groundwater protecting the resource. • Aquifer is a proven safe resource • May preclude up-gradient land uses that have • Defers capital investment in alternative pollution potential or require groundwater by sources such as another desalination placing public water supply on the discharge plant end of the groundwater system
2. It is recommended that • Increased biodiversity and increased • Decreased opportunity for alternative land uses wetlands, threatened resilience of ecosystems to climate • Protection of ecosystems which may become species, threatened change unviable with climate change and variability ecological communities • Protection of intrinsic social, cultural • High cost of establishment and Bush Forever areas and landscape values and social • Reduces the ability to maximise recharge be protected, and that amenity ecological linkages be • Very strong community support established. • Supports property values • Legal requirement
3. It is recommended that all • Increased groundwater supplies to • Increased risk of contamination of groundwater stormwater be redirected into provide additional use options • Capital costs of stormwater diversion the Superfi cial aquifer. • Reduced saltwater intrusion risks for both public and private water users • Improved social amenity for local residents • Reduced contamination of ocean and beaches
4. It is recommended that the • Opportunity to implement Network • Further impacts on Quindulup Dune system and GSS support, in general, City principles reduced opportunities for ecological linkages the North-West corridor • Planning already well advanced • Vastly inadequate land allocated to employment structure plan subject to • General community support generating uses further consideration of: • Relatively few landholders, thus • Coastal borefi elds are subject to management of • sea level change and its providing the ability to strategically up-gradient pollutants and salt water intrusion impact on saltwater intrusion plan land use and inundation • Good quality groundwater available in • protection of ecological the coastal zone linkages, particularly as • Serviced by rail and freeway access they relate to the Quindalup • Green fi eld sites that can incorporate Dune system and east-west latest water conservation design linkages • Opportunities to use recycled water • provision of additional land from wastewater treatment plants for for employment generating horticulture or recharge of the aquifer uses • Distance from and down-gradient • use of recycled water from the Priority 1 Water source • provision of adequate protection area transport linkages that • Important wetlands and ecological have regard to potential sites protected as parks and environmental impacts. recreation in the Metropolitan Region Scheme
48 Gnangara Sustainability Strategy Appendix 1 Zone 4 – Quinns Rock, Eglinton Zone Gnangara groundwater system zone plans and Yanchep-Two Rocks subareas
July 2009
4.6 Recommendations to address water and land management issues in Zone 4
Management Issue Explanation Recommendations consideration
4.6.1. 4.6.1.1 • Public water supply and bores It is recommended that: Public water supply Public water (Figure 9): 1. the groundwater resource for public management supply o Zone 4 borefi elds: Neerabup (Quinns) water supplies be developed and and Neerabup treatment plant protected. o 2007–08 borefi eld abstraction was 2. the location of the coastal borefi eld 24.2 GL. Abstraction by aquifer: needs to be carefully planned to: Superfi cial 15.4 GL and Leederville • reduce saltwater intrusion risks 8.82 GL • take account of up-gradient land • As the population grows in this northern uses that may want to use treated coastal strip, the abstraction along the wastewater or may add pollutants coast will grow with demand. Coastal • avoid competition with private bores draw largely from the Superfi cial and local government users of and Leederville aquifers. Groundwater groundwater. levels are falling around the coastal borefi elds and are yet to reach a new equilibrium
4.6.1.2 • In some areas bores along the coast 3. It is recommended that public supply Saltwater experience a seasonal increase in bores in the coastal scheme be carefully intrusion salinity levels that may be due to monitored, as there is potential for upconing – vertical movement of the drawing the seawater interface inland. interface beneath the bore • Seawater intrusion can also occur in the Leederville aquifer where the aquifer is in contact with the Superfi cial aquifer near Quinns Rock • Research to provide a greater understanding of the system and of the movement of salt water is being undertaken
4.6.1.3 • A considerable volume of stormwater It is recommended that: Recycled drainage is infi ltrated to the groundwater 4. options for use of the water from the water in the Gnangara system and Alkimos wastewater treatment plant be opportunities to promote local-scale explored at an early stage before its use of a further portion of this water development precludes uses. should be encouraged 5. groundwater replenishment to the Superfi cial aquifer be investigated for combined environmental and drinking water supply benefi ts. 6. opportunities to promote local-scale use of stormwater that currently discharges into the ocean be encouraged.
49 Zone 4 – Quinns Rock, Eglinton Gnangara Sustainability Strategy Appendix 1 Zone and Yanchep-Two Rocks subareas Gnangara groundwater system zone plans
July 2009
4.6 Recommendations to address water and land management issues in Zone 4
Management Issue Explanation Recommendations consideration
4.6.2 4.6.2.1. • Existing and proposed land uses It is recommended that, in general, the Urbanisation and North-west are generally refl ected in the zones GSS support: commercial use corridor and reserves of the Metropolitan 7. th e North-West corridor structure plan. planning Region Scheme. The GSS Zone 4 will 8. the development of urban deferred predominantly be urban with activity land with the proviso that the Western centres, activity corridors, transport Australian Planning Commission corridors and signifi cant parcels of consider ecological linkages, parks and recreation employment generating land use, rising • The north-west corridor has been sea levels and saltwater intrusion. divided into four areas, two of which are in GSS Zone 4. These are: o North-west – ‘developing and future urban’ – which includes the north- west urban expansion areas of Butler, Jindalee, Alkimos, Eglinton, Yanchep and Two Rocks (St Andrews). Market forces for the supply of residential land in this area have driven the formulation of a number of more detailed plans including the Butler- Jindalee district structure plan, Alkimos-Eglinton district structure plan and the St Andrews district structure plan for the Yanchep–Two Rocks areas. All of these district structure plans are at differing stages of formulation, negotiation and adoption by the Western Australian Planning Commission o South-west – ‘developed urban’ – which includes the existing urban areas between Hepburn Avenue, Lukin Drive and west of Wanneroo Road. Major projects in this area include Burns Beach residential subdivision, the extension of the Mitchell Freeway, and the extension of the northern line transit system
50 Gnangara Sustainability Strategy Appendix 1 Zone 4 – Quinns Rock, Eglinton Zone Gnangara groundwater system zone plans and Yanchep-Two Rocks subareas
July 2009
4.6 Recommendations to address water and land management issues in Zone 4
Management Issue Explanation Recommendations consideration
4.6.2.2 • There is a signifi cant shortage of 9. It is recommended that the current Employment employment generating land in Zone 4 structure planning processes identify generating to provide employment opportunities and zone more employment generating land for the rapid population growth in this land in the north-west corridor and in area. Part of this demand will be met the GSS Zone 4. by the Neerabup industrial area in the long term but this site has signifi cant constraints and additional sites will most likely be critical to the ability of the corridor to achieve long-term employment self-suffi ciency targets and avoid ineffi cient transportation patterns developing • Intensive employment activities in proximity to employment sources are vital to achieving sustainable urban forms and transportation networks. There is potential for expansion into adjacent state forest, once the existing pine has been harvested. This would require an amendment to the Priority 1 Water source protection area
4.6.2.3 • The recently completed Industrial lands 10. It is recommended that the current Requirement needs study, 2008 identifi ed the need structure planning processes identify for industrial for additional employment generating and zone more employment generating land land of up to 3100 ha by 2030 in the land in the north-western corridor and in Perth–Peel Region, with approximately the GSS Zone 4. 730 ha required in the north-west sector. The second stage of this study is currently underway and will examine potential industrial sites throughout the Perth–Peel region • More industrial land is required in the north-west corridor or in close proximity if employment targets are to be met
4.6.2.4 • A ready supply of basic raw materials 11. To meet the requirements for basic raw Extraction close to established and developing materials, it is recommended that basic of basic raw parts of the Metropolitan region is raw materials should be protected for materials essential to keep land development mining and eventually be rehabilitated, costs down and contribute to affordable once extraction is completed, for other housing. Priority resource locations and long-term uses appropriate to the GSS. key extraction areas as defi ned inState planning policy 2.4 Basic raw materials July 2000 are shown in Figure 3.11 of the Situation statement • There are basic raw materials, principally sand and limestone, located in Zone 4
51 Zone 4 – Quinns Rock, Eglinton Gnangara Sustainability Strategy Appendix 1 Zone and Yanchep-Two Rocks subareas Gnangara groundwater system zone plans
July 2009
4.6 Recommendations to address water and land management issues in Zone 4
Management Issue Explanation Recommendations consideration
4.6.3 4.6.3.1 • The quality, variety and accessibility of It is recommended that: Land use management Water public open space is important for the 12. all new developments adopt sensitive physical, mental and social wellbeing of water sensitive design principles urban design communities. Currently 39 GL of water which incorporate the sustainable and public is used to irrigate public open space management and integration open space across the GSS study area of stormwater, wastewater and • Approximately 0.8 GL is used to irrigate groundwater supply into urban design. public open space in this zone (see 13. public open space be managed Figure 8) with greater water and nutrient use effi ciencies by encouraging local government to: • monitor water use • maintain water effi cient irrigation systems • develop best practice systems • redevelop public open space using hydrozones and ecozones. 14. all stormwater be redirected into the Superfi cial aquifer, some of which could be used for public open space. 15. regional water management strategies be produced. 16. at a sub-divisional level, all developers produce a water plan.
4.6.3.2 • In Zone 4, the risk of acid sulphate 17. It is recommended that monitoring and Acid sulphate soils in Yanchep–Two Rocks, Eglinton investigation of potential acid sulphate soils and Quinns Rock subareas is generally soils be undertaken. considered low, mainly due to the high buffering capacity of the coastal and Spearwood Dune sands
52 Gnangara Sustainability Strategy Appendix 1 Zone 4 – Quinns Rock, Eglinton Zone Gnangara groundwater system zone plans and Yanchep-Two Rocks subareas
July 2009
4.6 Recommendations to address water and land management issues in Zone 4
Management Issue Explanation Recommendations consideration
4.6.4 4.6.4.1 • Quindalup and Cottesloe central and It is recommended that : Biodiversity Ecological south vegetation complexes are under- 18. protection be given to suffi cient area linkages represented in the formal conservation of the Quindalup and Cottesloe central estate on the Swan coastal plain and and south complex which are under- require protection. represented in the formal conservation • Large areas of remnant vegetation estate on the Swan coastal plain. remain on the beach (Quindalup) dunes 19. remnant bushland and ecological in the Eglinton and Yanchep–Two Rocks linkages be protected in the planning subareas, but these are planned to be process, including linkages from cleared for future urban development Neerabup and Yanchep national parks • Bush Forever and the Perth Biodiversity to the coast and along the coastal project identifi ed four ecological dunes. linkages in Zone 4. The City of 20. these linkages be incorporated into Wanneroo has identifi ed a number of structure plans and the Metropolitan local corridors. The GSS proposes Region Scheme and that they be seven priority ecological linkages in supported by local government, Zone 4 (two north-south and fi ve east- Department for Planning and west) which will provide a link to large Infrastructure and the Western areas of bushland in Neerabup and Australian Planning Commission. Yanchep National Park, Wilbinga and along the coast • The identifi ed ecological linkages need to be incorporated into structure plans and supported by local government, the Department for Planning and Infrastructure and the Western Australian Planning Commission
4.6.4.2 • The threatened ecological community It is recommended that: Threatened Limestone ridges (SCP 26a) has 23 21. threatened fl ora, fauna and fl o r a , occurrences within Zone 4 ecological communities be managed fauna and • Threats to the Limestone ridges in accordance with the Wildlife ecological community include clearing for mining Conservation Act 1950 (WA), and the communities operations and too frequent fi re with relevant recovery plans for threatened subsequent weed invasion. The and priority species and ecological impacts of hydrological changes on this communities. community is largely unknown 22. where applicable, threatened fl ora, fauna and ecological communities be managed in accordance with the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth).
53 Zone 4 – Quinns Rock, Eglinton Gnangara Sustainability Strategy Appendix 1 Zone and Yanchep-Two Rocks subareas Gnangara groundwater system zone plans
July 2009
4.6 Recommendations to address water and land management issues in Zone 4
Management Issue Explanation Recommendations consideration
4.6.4.3 • There are few effective options available It is recommended that: Wetlands and for managing some wetlands under 23. wetland biodiversity values and wetland groundwater drying climate scenarios where there complexes be identifi ed and prioritised. dependent is either a long lag time in groundwater 24. the feasibility of maintaining or ecosystems recovery or no recovery recovering those wetlands and groundwater dependent ecosystems affected by groundwater decline be determined. 25. further analyses of risks and cost- benefi ts of alternative management options be undertaken. 26. an assessment be undertaken of the relative merits of the continued augmentation of wetlands in a drying climate compared with other alternative uses of groundwater. 27. remaining wetlands and groundwater dependent ecosystems be monitored and protected from development. 28. it be determined whether there are any wetlands or groundwater dependent ecosystems that should be incorporated into any future review of ministerial criteria sites.
54 Gnangara Sustainability Strategy Appendix 1 Zone 4 – Quinns Rock, Eglinton Zone Gnangara groundwater system zone plans and Yanchep-Two Rocks subareas
July 2009
Figure 9 Zone 4 public water supply borefi elds
55 Zone 5 plan – Gingin Brook 1,2,3 and 4 and Lake Mungala subareas Zone 5 Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
5.1 Overview Local governments
Land use in Zone 5 is largely rural and semi-rural City of Wanneroo, Shire of Gingin, Shire of with dryland agriculture the dominant land use Chittering, City of Swan across the zone. Bush Forever sites are situated in Gingin Brook 1 subarea, providing important Population in 2006 ecological linkages. There are further opportunities for ecological linkages in the other zones. Gingin Brook 1 – 595, Gingin Brook 2 – 105, Gingin Brook 3 – 29, Gingin Brook 4 – 303, Lake While most of Zone 5 lies outside the Priority 1 Mungala – 634 Water source protection area, being on the edge of the Gnangara Mound, groundwater recharge Land form (surface geology) is considered as the ‘window of recharge’ for the Yarragadee and Leederville aquifers. Upward Quindalup Dunes, Spearwood Dunes, leakage from the Yarragadee and Leederville Bassendean, Guildford Clay aquifers into the Superfi cial aquifer also occurs. These ‘windows’ are extremely important for water Wetlands management across the system. Conservation wetlands exist across the subarea. Lake Muckenburra, Lake Bambun, Lake Nambury, There have already been signifi cant declines in Lake Mungala, Lennard Brook, Moore River groundwater levels of up to 4 metres across some estuary, Gingin Brook, Ellen Brook subareas. Indigenous sites of signifi cance
Percentage of 29, including Moore River, Guilderton Bridge, Subarea Land area ha total GSS area Guilderton South, Moore River South
Gingin Brook 1 8569 4.0
Gingin Brook 2 2850 1.3 5.2 Allocation status of Zone 5 Gingin Brook 3 6116 2.8 The GSS zone and subarea boundaries differ from Gingin Brook 4 8112 3.8 the current water allocation management area boundaries used by the Department of Water. Lake Mungala 8104 3.8 The Gnangara groundwater area is proclaimed in accordance with s.26B of the Rights in Water and Irrigation Act 1914 (Figure 15).
56 Gnangara Sustainability Strategy Appendix 1 Zone 5 – Gingin Brook 1, 2, 3 and 4 Zone Gnangara groundwater system zone plans and Lake Mungala subareas
July 2009
As of December 2008 the licensed groundwater • There is no additional water available from allocation status for gazetted groundwater subareas Leederville and Yarragadee aquifer in this which fall within GSS Zone 5, is as follows (see zone. Figure 10): Predicted continued reduction in recharge from rainfall will reduce water availability in future years. • The draft Gnangara groundwater areas Changes in current land use may alter this trend management plan (2008) set allocation limits within this zone. which indicate that groundwater subareas in the Superfi cial aquifer are 100 to 139 per cent allocated under the current climate and In Zone 5 the GSS recommends that in the future current land and water use. water be allocated as a periodic share of available water, which will enable allocations to refl ect the • The current water management strategy in inter-annual and seasonal availability of water. over allocated areas is to cap use (so no new licences are issued) reduce use through The GSS also recommends that there is no net effi ciency and recover water where licensing expansion of horticulture in the zone and that processes allow. abstraction for horticulture and public open space is reduced through greater water use effi ciencies. Total • A small volume of water is available from private abstraction should be reduced by around 20 the Deepwater Lagoon South groundwater per cent. subarea.
Figure 10 Zone 5 2008 licensed groundwater allocation – 23.6 gigalitres
57 Zone 5 – Gingin Brook 1, 2, 3 and 4 Gnangara Sustainability Strategy Appendix 1 Zone and Lake Mungala subareas Gnangara groundwater system zone plans
July 2009
The area that recharges the Yarragadee aquifer • protect the Moore River and Gingin Brook needs special management to maintain recharge (sense of place, water quality, biodiversity rates in a drying climate. and Indigenous cultural values)
• manage salt water intrusion from the ocean Under this recommendation groundwater levels in and the Moore River this zone are expected to remain relatively stable or experience only modest declines. • promote tourism
There are no estimates of unlicensed use in the • protect wetlands, threatened ecological Superfi cial aquifer available for Zone 5. communities, threatened species and under- represented vegetation complexes
5.3 Issues • protect social and cultural values
• prevent the formation of acid sulphate soils. The most important issues that need to be addressed within Zone 5:
• the zone’s water resources are over allocated, with the Lake Mungala subarea being signifi cantly over-allocated
• the increased salt load and nutrient levels from adjacent rural and horticultural land uses into the Moore River, with the health of the lower system deemed to be threatened
• managing nutrient runoff in to watercourses and wetlands, including the Ellen Brook and its tributaries
• management of acid sulphate soils.
5.4 Objectives
The objectives of the Gnangara sustainability strategy for Zone 5 are to:
• restore Gingin Brook, Moore River and Ellen Brook riparian zones
• maximise groundwater recharge
• protect water quality
• manage winter fl ooding
• maintain rural production and productivity
• manage surface and groundwater abstraction
• assess potential for public water supply to Woodridge estate
58 Gnangara Sustainability Strategy Appendix 1 Zone 5 – Gingin Brook 1, 2, 3 and 4 Zone Gnangara groundwater system zone plans and Lake Mungala subareas
July 2009
5.5 Recommendations for the whole of Zone 5 with associated benefi ts and risks
Recommendation Benefi ts Risks
1. It is recommended that: • Reduced impact of nutrients and • Lack of mechanisms to limit horticulture • there be no net expansion of water on downstream values • Uncertainty over water and land security may horticulture in this zone • Horticulture contributes to Perth’s affect growers capacity and/or willingness to • water be allocated refl ecting food needs and security invest in water and nutrient effi ciency practices a periodic share of available • Aquifer managed sustainably • Economic impact on horticulturalists of reduced water allocations • all users be encouraged to adopt water and nutrient effi ciencies through the use of licences and other tools such as metering, education and incentives. • horticultural practices which use water and nutrient best practices and alternate production methods such as hydroponics be encouraged.
2. It is recommended that • Increased biodiversity • Reduces alternative land use opportunities Wilbinga unallocated crown • Protection of threatened ecological land, which forms a vital communities link between the Banksia • Increased biodiversity and increased woodland in the east and the resilience of ecosystems to climate coast, be retained. change • This has been a long standing recommendation
3. It is recommended that • Water quality protected, including • As this area is outside of the Metropolitan Moore River, Ellen Brook and nutrient loads into the Swan River and Region Scheme, there is no clear mechanism for Gingin Brook be protected Moore River estuaries purchase of public open space for conservation by catchment management • Maintenance of biodiversity values or recreation practices such as riparian and social values • Cost of rehabilitation to be met by multiple small fencing, protection of native landholders vegetation, reservation and revegetation.
59 Zone 5 – Gingin Brook 1, 2, 3 and 4 Gnangara Sustainability Strategy Appendix 1 Zone and Lake Mungala subareas Gnangara groundwater system zone plans
July 2009
5.6 Recommendations to address water and land management issues in Zone 5
Management Issue Explanation Recommendations consideration
5.6.1 5.6.1.1 • There are no public water supply bores Public water supply Public water in Zone 5 management supply
5.6.1.2 • The interactions between the It is recommended that: Interaction groundwater and surface waters in the 1. water quantity, quality and biodiversity between Moore River estuary and Gingin Brook assets, river banks and tuart stands be groundwater are dynamic, with water levels in the two protected. and rivers systems being closely interlinked. Much 2. an assessment of the Moore River of the surface water fl ow is derived from and Gingin catchment for suitability groundwater and recognition as a regional park be • Elevated nutrient levels exist in the undertaken. aquifers and rivers of the lower Moore 3. assessment of the use of surface and River, Gingin Brook and Ellen Brook. groundwater resources in the Gingin Groundwater to the south of Gingin Brook subareas continue. Brook contains elevated nutrient 4. the riparian zones along the Gingin concentrations which are considered to Brook, Ellen Brook and their seasonal adversely affect Gingin Brook and the tributaries be restored. lower Moore River estuary 5. assessments be undertaken of the high • Nutrient enrichment of the lower Moore phosphorus and nitrogen loads into River system is an issue of signifi cant Gingin Brook, Ellen Brook and the main concern. The continued health of the tributaries from agricultural drainage. lower system is deemed threatened 6. the GSS supports the Department of by nutrients washing off and leaching Water studies along Gingin Brook and into the catchment from agriculture. Gnangara North which aim to better Nutrient concentrations in the estuary understand the interaction between vary seasonally, being affected by groundwater and rivers. surface fl ows in winter and year-round 7. groundwater and surface water groundwater movement resources be managed in a coordinated manner.
5.6.2 5.6.2.1 • Moore River and Gingin Brook are It is recommended that: Urbanisation and Urban important wetlands and are likely to 8. the GSS support the Western Australian commercial use development represent unique and high biodiversity Planning Commission/Department for values Planning and Infrastructure position of • The majority of this zone is north of opposing any intensive development of the Metropolitan Region Scheme and the southern side of the Moore River. is covered by the Shire of Gingin and 9. the GSS support the Western Australian Chittering local government town Planning Commission/Department for planning schemes Planning and Infrastructure position • Most of this area is zoned rural in of no urban development in this zone, the local government town planning north of Bullsbrook. schemes
60 Gnangara Sustainability Strategy Appendix 1 Zone 5 – Gingin Brook 1, 2, 3 and 4 Zone Gnangara groundwater system zone plans and Lake Mungala subareas
July 2009
5.6 Recommendations to address water and land management issues in Zone 5
Management Issue Explanation Recommendations consideration
5.6.2.2 • A ready supply of basic raw materials 10. It is recommended that basic raw Extraction close to established and developing materials be protected for mining of basic raw parts of the Metropolitan region is and that the land should eventually materials essential to keep land development be rehabilitated, once extraction costs down and contribute to affordable is completed, for long-term uses housing. Priority resource locations and appropriate to the GSS. key extraction areas as defi ned inState planning policy 2.4 Basic raw materials July 2000 are shown in Figure 3.11 of the Situation statement • There are basic raw materials located in Zone 5
5.6.3 5.6.3.1 • The most signifi cant economic It is recommended that: Land use Agriculture broadacre land use is grazing of 11. horticulture be constrained to current management and legume-based annual pastures. Beef operations. horticulture cattle for yearling production, and 12. water allocations refl ect a periodic share horses for the racing industry and of available water. other equestrian activities are the main 13. freehold pasture land continue to be grazing livestock managed to maximise recharge. • Chicken meat production is the most 14. total private licensed abstraction should important intensive agriculture activity be reduced by around 20 per cent. in the zone. Other important industries 15. all users be encouraged to adopt water include pig meat and nutrient effi ciencies through the • Horticulture is important in parts of use of licences and other tools such as Gingin Brook 1 and 2 subareas with metering, education and incentives. carrots, citrus, avocadoes, mangoes 16. horticultural practices which use and leafy vegetables amongst the crops water and nutrient best practices and grown alternate production methods such as hydroponics be encouraged. 17. nutrient infl ows into the Moore River, Gingin Brook and Ellen Brook from dryland agriculture and horticulture be managed. 18. effi cient land use practices are adopted to minimise leaching of nutrients into groundwater. 19. impacts on groundwater from horticulture users in the Gingin area be investigated, although this area is outside of the study area.
61 Zone 5 – Gingin Brook 1, 2, 3 and 4 Gnangara Sustainability Strategy Appendix 1 Zone and Lake Mungala subareas Gnangara groundwater system zone plans
July 2009
5.6 Recommendations to address water and land management issues in Zone 5
Management Issue Explanation Recommendations consideration
5.6.3.2 • The quality, variety and accessibility of It is recommended that: Water public open space is important for the 20. all new developments adopt water sensitive physical, mental and social wellbeing, of sensitive design principles which urban design communities. Currently 39 GL of water incorporates the sustainable and public is used to irrigate public open space management and integration open space across the GSS study area of stormwater, wastewater and • Approximately 0.18 GL is used to irrigate groundwater supply into urban design. public open space in this zone (see 21. public open space be managed Figure 10) with greater water and nutrient use effi ciencies by encouraging local government to: • monitor water use • maintain water effi cient irrigation systems • develop best practice systems • redevelop public open space using hydrozones and ecozones.
5.6.3.3 • In Zone 5, mapping predicts a low to 22. It is recommended that monitoring and Acid sulphate moderate risk of acid sulphate soils over investigation be undertaken to provide soils much of the Gingin Brook and Lake better understanding of the potential for Mungala subareas acid sulphate soils. • However, there are extensive areas of lakes and wetland sediments and their potential for acid sulphate soils is not well understood
62 Gnangara Sustainability Strategy Appendix 1 Zone 5 – Gingin Brook 1, 2, 3 and 4 Zone Gnangara groundwater system zone plans and Lake Mungala subareas
July 2009
5.6 Recommendations to address water and land management issues in Zone 5
Management Issue Explanation Recommendations consideration
5.6.4 5.6.4.1 • The remnant vegetation in this zone It is recommended that: Biodiversity Remnant (except in parts of the Gingin Brook 1 23. the Wilbinga unallocated crown land vegetation subarea) has been extensively cleared be vested with the Department of and for rural development and many of Environment and Conservation under ecological the vegetation complexes present are the CALM Act 1984 in order to form a linkages poorly represented in the conservation vital link between the Banksia woodland estate in the east and the coast. This area of • Priorities for additional protection in the remnant vegetation is within Gnangara eastern side of the Swan coastal plain Park as well as being listed as a Bush include the Yanga complex, which has Forever site. less than 30% remaining across the 24. the regionally important bushland plain, and the Coonambidgee complex be reserved in the Shire of Gingin which has less than 30% protected Town Planning Scheme to refl ect its within the GSS study area ecological value and preservation. • A large block of remnant vegetation 25. a study be conducted to examine remains in the southern coastal part of whether Moore River and Gingin Brook the Gingin Brook 1 subarea (referred to catchments should be classifi ed as as ‘Wilbinga’) and has been identifi ed as a unique and high biodiversity value having regionally signifi cant biodiversity catchment. values by Bush Forever 26. a study be conducted to identify • Bush Forever did not cover most of regionally signifi cant biodiversity assets Zone 5 (as it is north of the Metropolitan within Zone 5 along similar lines as Region Scheme), so regionally Bush Forever. important bushland and wetland sites have not been formally identifi ed. There are opportunities for ecological linkages and further conservation reserves across this zone. • Ten priority ecological linkages have been identifi ed within Zone 5, including linkage along the coast and to large areas of protected bushland in Gnangara Park, Yeal Nature Reserve and outside the GSS study area into the Darling Scarp, Dandaragan Plateau and Moore River Nature Reserve • The identifi ed ecological linkages need to be incorporated into structure plans and be supported by local government, the Department for Planning and Infrastructure and the Western Australian Planning Commission
63 Zone 5 – Gingin Brook 1, 2, 3 and 4 Gnangara Sustainability Strategy Appendix 1 Zone and Lake Mungala subareas Gnangara groundwater system zone plans
July 2009
5.6 Recommendations to address water and land management issues in Zone 5
Management Issue Explanation Recommendations consideration
5.6.4.2 • Five threatened ecological communities It is recommended that: Threatened which are restricted to the eastern side 27. threatened fl ora, fauna and fl o r a , of the Swan coastal plain and which are ecological communities be managed fauna and all communities dependent on seasonal in accordance with the Wildlife ecological water are present in Zone 5. Clearing, Conservation Act 1950 (WA), and the communities too frequent fi re, dropping watertable relevant recovery plans for threatened and weed invasion threaten these and priority species and ecological communities communities. • Five declared rare fl ora and 13 priority 28. where applicable, threatened fl ora, fl ora species are also present fauna and ecological communities • Only limited information is available on be managed in accordance with the fauna in most of Zone 5 Environment Protection and Biodiversity Conservation Act 1999 (Cwlth).
5.6.4.3 • The Moore River and Gingin Brook It is recommended that: Wetlands and are important wetlands representing 29. water quantity, quality and biodiversity groundwater a unique and high biodiversity value assets, river banks and tuart stands be dependent catchment on the Swan coastal plain. protected. ecosystems Ecological linkages have been identifi ed 30. an assessment of the Moore River along the Moore River, Gingin and Ellen and Gingin catchment for suitability brooks. Targeted restoration of these and recognition as a regional park be riparian zones and other seasonal undertaken. tributaries would provide the added 31. assessment of the use of surface and benefi t of improving surface water groundwater resources in the Gingin quality by nutrient amelioration and soil Brook subareas continue. amendment 32. the riparian zones along the Gingin • There is little data available for a range Brook, Ellen Brook and their seasonal of diverse lakes and seasonal streams tributaries be restored. that occur in this zone and include more 33. assessments be undertaken of the high or less permanent black-water wetlands phosphorus and nitrogen loads into (including the area just north of Moore Gingin Brook and Ellen Brook and into River and portions of the Pinjarra Plain). agriculture drainage (Ellen Brook and It is likely that these areas contain Gingin Brook and the main tributaries). endemic, and perhaps rare, species, 34. remaining wetlands and groundwater including fi sh dependent ecosystems be monitored • Priority listed semi-aquatic species exist and protected from development. in Zone 5. 35. it be determined whether there are any • Private property and small reserves wetlands or groundwater dependent containing lakes and wetlands within ecosystems that should be incorporated the Lake Mungala subarea provide into any future review of ministerial important habitat for numerous species criteria sites. • The impacts of hydrological changes on the priority fl ora are largely unknown. Mitigating against other threatening processes is vital to allow threatened fl oral species and ecological communities to have the adaptability to cope with altered hydrology and climate change
64 Zone 6 plan – West Yanchep, East Yanchep and Banksia subareas Zone 6 Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
6.1 Overview an area of unallocated Commonwealth crown land managed for use by the RAAF. The majority of land in this zone is within the Priority 1 Water source protection area. The zone is bounded to the west by rural and urban areas, to the south by rural land, state forest and Banksia woodland on RAAF unallocated crown land, Pine plantations are located across the East and rural areas to the east and north. Yanchep subarea. Tuart woodland and heath are found across West Yanchep and Banksia woodland is found in the Banksia subarea. Signifi cant and large Percentage of Bush Forever sites are situated across the zone. Subarea Land area ha These provide ecological linkages to the Yanchep total GSS area National Park. Signifi cant limestone resources occur in the western half of this zone. West Yanchep 14 718 6.8
East Yanchep 17 524 8.1 Zone 6 has signifi cant social, cultural and ecological values associated with the groundwater dependent Banksia 38 196 17.8 features. Yanchep National Park, one of Perth’s most popular tourist attractions, provides important Local governments cultural, recreational and educational opportunities associated with the wetlands and cave systems. City of Wanneroo, Shire of Gingin, Shire of Groundwater level declines have affected the cave Chittering ecosystems of the national park and rare stygofauna communities are threatened. Population in 2006
Part of this zone is a signifi cant groundwater Minimal recharge area known as the ‘window of recharge’, for the Yarragadee and Leederville aquifers, Land form (surface geology) particularly in the Banksia subarea. Upward leakage from the Yarragadee and Leederville aquifers into Spearwood Dunes, Bassendean Dunes the Superfi cial aquifer in the West and East Yanchep subareas also occurs. Signifi cant declines in Wetlands groundwater levels of 5 to 6 metres have occurred in this zone since 1974. Loch McNess, Lake Yonderup, Lake Wilgarup, Pipidinny Swamp, Yeal Swamp, Central Yeal, Zone 6 is in the northern part of the Gnangara North-east Yeal, Lake Bindiar, Tangletoe Swamp, groundwater system and is distributed across Tick Flat, Barragoon Lake, Coppine Lake the main (Spearwood and Bassendean) dune formations on the Swan coastal plain. It is the Indigenous sites of signifi cance largest zone (32.77%) of the GSS study area. The 8, including Yonderup Cave, Loch McNess/ zone is predominantly crown land managed by the Wagardu Spring, Pipidinny Lake, Emu Cave, Department of Environment and Conservation, and Smokebush Waterhole 65 Zone 6 – West Yanchep, East Yanchep Gnangara Sustainability Strategy Appendix 1 Zone and Banksia subareas Gnangara groundwater system zone plans
July 2009
6.2 Allocation status of Zone 6 • A small volume of water is available from the Yanchep and Deepwater Lagoon South groundwater subareas. The GSS zone and subarea boundaries differ from the current water allocation management area • There is no additional water available from boundaries used by the Department of Water. the Leederville or Yarragadee aquifers in The Gnangara groundwater area is proclaimed in Zone 6. accordance with s.26B of the Rights in Water and Irrigation Act 1914 (Figure 15). Predicted continued reduction in recharge from rainfall will reduce water availability in future years. As of December 2008 the licensed groundwater Changes in current land use may alter this trend. allocation status for gazetted groundwater subareas which fall within GSS Zone 6, is as follows (see In Zone 6 the GSS recommends that pine Figure 11): removal be accelerated where possible, within the economics of existing commercial agreements to • The draft Gnangara groundwater areas increase the opportunity for recharge to both the management plan (2008) set allocation limits Superfi cial and Leederville aquifers. which indicate that groundwater subareas in the Superfi cial aquifer are 100 per cent (i.e. Unless under ecological linkages, post-pine land fully) allocated under the current climate and uses should encourage recharge to reduce the area current land and water use. that will experience lower groundwater levels in
Figure 11 Zone 6 2008 licensed groundwater allocation – 11.2 gigalitres
66 Gnangara Sustainability Strategy Appendix 1 Zone 6 – West Yanchep, East Yanchep Zone Gnangara groundwater system zone plans and Banksia subareas
July 2009
future. Groundwater levels in the Banksia and West 6.4 Objectives Yanchep subareas may be higher if increased fuel reduction burning is shown to be environmentally The objectives of the Gnangara sustainability benign or benefi cial. strategy for Zone 6 are to:
If the GSS recommendations are adopted, • protect wetlands, caves, Bush Forever sites groundwater levels will increase after pine removal and regional bushland and have lower rates of decline under native vegetation if more frequent burning is feasible. • arrest groundwater level decline in the Superfi cial aquifer In addition to the licensed use of water outlined above, it is estimated that approximately 0.77 • promote recharge in the ‘window of gigalitres of water is abstracted from the Superfi cial recharge’ to the confi ned aquifers aquifer for unlicensed use. Unlicensed use includes • protect water quality for public water supply taking of water for stock and domestic purposes in (Priority 1 Water source protection area) addition to use for domestic garden bores. • protect large blocks of bushland and 6.3 Issues promote connectivity, and hence environmental resilience to climate change and variability The most important issues that need to be addressed within Zone 6: • support and manage limestone extraction
• maintain recreation and ecotourism access • the need to protect the Superfi cial aquifer to Yanchep National Park and disturbed from water level declines and to ensure areas in the East Yanchep subarea water quality for public water supply • manage Phytophthora cinnamomi dieback • the protection of recharge in to the ‘window of recharge’, for the Yarragadee and • protect social and cultural values Leederville aquifers • manage timber resources and commercial • the protection and maintenance of social forestry in a sustainable manner and cultural values associated with Yanchep National Park • limit access in the Banksia subarea, including recreational access • the post-pine harvesting land use across Yanchep and Pinjar pine plantations • prevent the formation of acid sulphate soil risk on peat soils from groundwater decline • the protection of cave ecosystems, and fi re signifi cant wetlands and threatened species • accommodate new transport corridors to • the management of acid sulphate soils meet Network City objectives
• the demand for large areas of land to • investigate critically important strategic accommodate employment generating uses employment generating land uses. and provide a vital strategic employment anchor at the northern end of the north-west corridor.
67 Zone 6 – West Yanchep, East Yanchep Gnangara Sustainability Strategy Appendix 1 Zone and Banksia subareas Gnangara groundwater system zone plans
July 2009
6.5 Recommendations for the whole of Zone 6 with associated benefi ts and risks
Recommendations Benefi ts Risks
1. It is recommended that fi re • Achieves a temporal and spatial • Neither optimising groundwater recharge nor management in Banksia balance between water recharge and terrestrial biodiversity woodland be optimised to biodiversity • Possible increase in wildfi res if less burning is help balance groundwater • Protects top of Gnangara Mound and carried to benefi t biodiversity recharge and terrestrial and ‘windows’ to confi ned aquifers • Increased frequency of smoke, but may be lower aquatic biodiversity values. • Cost-effective option intensity smoke and fi res • Protection of social value and amenity • Increased aquatic biodiversity
2. It is recommended that: • Maximises recharge • Reduces land available for employment • biodiversity be maximised by • Protects biodiversity generation protecting bushland • Retains social amenity • Potential for unauthorised access to forest with • the ‘window’ of the top of • Protects confi ned ‘windows’ consequent threat of contamination, spread of the Gnangara Mound be • Maximise biodiversity dieback protected • Protection of resilience of function with • ‘Locking up’ land so that it is not available for • the Priority 1 Water source climate change and variability alternative land uses protection area be protected. • Retention of social and cultural values associated with bushland • Compatible with Priority 1 Water source protection area, Bush Forever and Metropolitan Region Scheme
3. It is recommended that the • Increased opportunity for recharge to • Markets may not be available for timber products removal of pine plantations aquifers • Loss of food source for the endangered should be accelerated Carnaby’s black cockatoo where possible, within the • In subareas where there is no further replanting terms of existing commercial of pines the Gnangara sustainability strategy’s agreements. recommended post-pine landuse changes may need to be assessed under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), which protects nationally listed threatened species such as the Carnaby’s black- cockatoo
4. It is recommended that • Employment opportunities and • Possible impact on groundwater resources from the long-term potential meeting self-suffi ciency targets contamination for civic and institutional • Revenue from land sale available for • Increased pressures on groundwater resources uses and development of other uses such as management of • Lost opportunity for carbon credits critically important strategic state forest • A carbon defi cit employment generating • Meeting future need for civic and uses in the disturbed East institutional uses Yanchep subarea (post-pine) • Does not affect conservation values be investigated. • Maximises recharge for Yanchep Caves maintenance in the medium term
68 Gnangara Sustainability Strategy Appendix 1 Zone 6 – West Yanchep, East Yanchep Zone Gnangara groundwater system zone plans and Banksia subareas
July 2009
6.5 Recommendations for the whole of Zone 6 with associated benefi ts and risks
Recommendations Benefi ts Risks
5. It is recommended that • Social values connected to • Threat of spread of dieback with increased opportunities be developed recreational opportunities are public access for active and passive increased • Increased risk of fi re and weeds recreation in East and West • Potential to address public health • Fragmented bushland reducing resilience Yanchep subareas. issues associated with a lack of • Possible impact on groundwater resources from exercise contamination • Opportunity for major recreational • Increased pressures on groundwater resources node • Meets the needs of regional open space requirements of the City of Wanneroo
69 Zone 6 – West Yanchep, East Yanchep Gnangara Sustainability Strategy Appendix 1 Zone and Banksia subareas Gnangara groundwater system zone plans
July 2009
6.6 Recommendations to address water and land management issues in Zone 6
Management Issue Explanation Recommendations consideration
6.6.1 6.6.1.1 • Public water supply and bores (Figure 12): 1. It is recommended that public Public water supply Public water o Much of Zone 6 lies within Priority 1 Water water supply bores not be management supply source protection area constructed in this zone in order o Zone 6 borefi elds: top of the Pinjar borefi eld to protect the ‘windows’ into the o 2007–08 borefi eld abstraction was 9.5 GL. confi ned aquifers. This area is Abstraction by aquifer: Superfi cial 2.71 GL, the intake to the Leederville and Leederville 3.98 GL and Yarragadee 2.78 GL Yarragadee aquifers. • Immediately west of this zone coastal bores supply the Yanchep townsite and as population grows along the coastal strip, public water supply abstraction will grow with demand, and integrated water supply system trunk mains will be extended to the Yanchep area
6.6.1.2 2. It is recommended that on Fire completion of the Department of management Environment and Conservation’s to promote fi re regime trial (July 2010), recharge the optimum fi re regime that will maximise groundwater recharge, yet maintain the biodiversity values, should be implemented.
6.6.2 6.6.2.1 • The Urban industrial land study has identifi ed It is recommended that: Urbanisation and Requirement a shortfall of 3000 ha of industrial land and the 3. Zone 6 be considered for the commercial use for North-West corridor structure plan has identifi ed a location of critically important employment critical shortage of land to accommodate strategic strategic employment generating employment generating uses within the north-west generating uses that require land corridor large areas of land compatible with Priority 1, that are close to but separate from the general urban areas located in the adjacent Zone 4. Possible uses include research and development, industrial, correctional services, sporting facilities and related uses. 4. an evaluation of the Priority 1 Water source protection area and impacts on recharge to the Leederville aquifer to be considered.
6.6.2.2 • There is a need to accommodate new transport 5. It is recommended that new Requirement corridors to meet Network City objectives. This transport corridors be identifi ed for transport may require development subject to special to meet Network City and corridors conditions to protect the groundwater or the biodiversity objectives. amending of the Priority 1 boundary or both
70 Gnangara Sustainability Strategy Appendix 1 Zone 6 – West Yanchep, East Yanchep Zone Gnangara groundwater system zone plans and Banksia subareas
July 2009
6.6 Recommendations to address water and land management issues in Zone 6
Management Issue Explanation Recommendations consideration
6.6.2.3 • A ready supply of basic raw materials close It is recommended that: Extraction to established and developing parts of the 6. basic raw materials within Zone of basic raw Metropolitan region is essential to keep land 6 be extracted to meet the high materials development costs down and contribute to demand for sand and limestone affordable housing. Priority resource locations and in the Perth–Peel region. key extraction areas as defi ned inState planning 7. in order to extract basic raw policy 2.4 Basic raw materials July 2000 are shown materials without compromising in Figure 3.11 of the Situation statement future long-term development for urban and other purposes, sequential land use planning should be undertaken to make sure that extraction and rehabilitation can take place in a controlled way. 8. the availability of suitable road access be assessed. 9. extraction operations be staged to avoid confl icts with adjacent land use. 10. mining take place in disturbed areas wherever possible in order to protect bushland. 11. planning for basic raw material utilisation comply with recovery plans for the threatened ecological community (Limestone ridges SCP 26a) and the limestone threatened species (Eucalyptus argutifolia).
71 Zone 6 – West Yanchep, East Yanchep Gnangara Sustainability Strategy Appendix 1 Zone and Banksia subareas Gnangara groundwater system zone plans
July 2009
6.6 Recommendations to address water and land management issues in Zone 6
Management Issue Explanation Recommendations consideration
6.6.3 6.6.3.1 • Yanchep National Park and the northern part of 12. It is recommended that Yanchep Land use Yanchep Gnangara Park are in close proximity and have National Park and northern management National high conservation value, regional recreational Gnangara Park be retained and Park and value, tourism and a sense of place their management integrated Gnangara • The Forest management plan 2004–2013 (CCWA and resourced as key regional Park 2004) has proposed that some areas of state tourism, recreation and forest, within Gnangara Park, have their tenure conservation reserves. changed. These include: o the Wilbinga–Caraban bushland which has been identifi ed as being of signifi cant conservation value. It is currently State Forest 65 but it will eventually become a conservation park and a 5 (1)(h) reserve o a strip of state forest between Yeal Nature Reserve and Wilbinga–Caraban will change to nature reserve and be added to Yeal Nature Reserve o the state forest to the east of Yanchep National Park, known as Ridges, will become an extension to the park as its tenure changes to national park. • Contained within Gnangara Park is the RAAF managed unallocated crown land, which will remain under Commonwealth management for the foreseeable future • The Pinjar gas power station and associated extensive powerline infrastructure will affect surrounding land use and bushland by fragmenting ecological linkages and increasing the risk of dieback because of the increased access • Gnangara Park caters for active and regionally important recreational activities that may need buffers from housing or other uses
72 Gnangara Sustainability Strategy Appendix 1 Zone 6 – West Yanchep, East Yanchep Zone Gnangara groundwater system zone plans and Banksia subareas
July 2009
6.6 Recommendations to address water and land management issues in Zone 6
Management Issue Explanation Recommendations consideration
6.6.3.2 • The state government has two major timber supply It is recommended that: Pine agreements – WESFI and Wesbeam – which 13. standing pine be commercially plantation require a continuous supply of softwood timber removed from the Pinjar and until the end of 2025 and 2029 respectively. There Yanchep plantations in a is no agreement to replant harvested areas with targeted program by the Forest pine or other commercial forestry species Products Commission and • Since 2002 18 per cent of the total plantation area no further high density pine has been clear-felled replanting be undertaken. • The following table shows the area of land covered 14. the community be kept informed by pine plantation and the percentage of remaining of transitional plans and plantation to be harvested actions in removing pines and establishing new land uses. 2002 Sept Remaining Plantation 15. the community values of life and ha 2008 ha % property, plus the commercial Gnangara 6457 3558 55 timber resource, be protected Pinjar 7598 6748 89 from destructive wildfi res. Yanchep 7392 7089 96 16. monitoring of bores post-pines Total 21 447 17 395 81 be undertaken to assess the effect on the water balance. • Under the current harvesting regime of around 17. the size, number and location 1000 ha of clear-fall per annum across Zone 1, of ecological linkages through 2 and 6, the pine plantations will be removed by the cleared plantation are 2026 carefully designed to ensure that plantation management is practical and the opportunities for recharge and fi re control are optimised.
6.6.3.3 • The introduced European House Borer has 18. It is recommended that all European infected the Gnangara pine plantation and pine plantations in the East House Borer adjoining suburbs, including Ellenbrook, but has Yanchep subarea be kept not been found in the pine plantations in the East free of European House Borer Yanchep subarea infection. • It is a major strategy of the Forest Products Commission to systematically remove standing pine, pine timber debris and pine stumps from a two kilometre buffer in the West Pinjar subarea to protect the plantation in the north. This process would be signifi cantly assisted with the development of a bio-fuel plant that commercially uses the pine debris and stumps
73 Zone 6 – West Yanchep, East Yanchep Gnangara Sustainability Strategy Appendix 1 Zone and Banksia subareas Gnangara groundwater system zone plans
July 2009
6.6 Recommendations to address water and land management issues in Zone 6
Management Issue Explanation Recommendations consideration
6.6.3.4 • The risk of acid sulphate soils in Yanchep and East 19. It is recommended that Acid sulphate Yanchep is generally considered low, mainly due to monitoring and investigation of soils the high buffering capacity of the coastal dune and potential acid sulphate soils be Spearwood sands undertaken. • Mapping predicts a moderate to low risk of acid sulphate soils in the Banksia subarea, even though it is on grey sands with low buffering capacity and it contains many seasonal wetlands. However, the processes of soil and groundwater acidifi cation under native Banksia woodland and a declining watertable are not well understood
6.6.3.5 • A recent review of the Gnangara and Pinjar off It is recommended that: Recreation road vehicle Area (ORVA) for the Department of 20. the ex-pine plantation areas in Environment and Conservation has recommended the East Yanchep subarea be their retention and upgrade for the safety of riders. considered for use by a range If either ORVA is forced to close due to land use of recreational activities that changes, an alternative area should be investigated require buffers for separation in the ex-plantation in the East Yanchep subarea of users and for regional • The City of Wanneroo requires a site of 40 ha for recreational facilities that are regional open space compatible with recharge and • This area is the intake to the Yarragadee and water quality protection. Leederville aquifers 21. the extensive bushland areas in the Yanchep and Banksia subareas not be used for vehicular or intensive recreational activities or facilities unless they are approved in an area management plan under the CALM Act 1984. 22. these activities or facilities should complement recreational opportunities being provided in Yanchep National Park, Whiteman Park and in the remainder of Gnangara Park.
74 Gnangara Sustainability Strategy Appendix 1 Zone 6 – West Yanchep, East Yanchep Zone Gnangara groundwater system zone plans and Banksia subareas
July 2009
6.6 Recommendations to address water and land management issues in Zone 6
Management Issue Explanation Recommendations consideration
6.6.4 6.6.4.1 • The majority of the Banksia and West Yanchep It is recommended that: Biodiversity Remnant subareas retain their native vegetation. All remnant 23. Yanchep National Park be vegetation vegetation meets the Bush Forever criteria for retained and the proposed and regionally important bushland. This area is the northern Gnangara Park ecological largest continuous block of bushland in the GSS be supported with their linkages and the core conservation area for Gnangara Park, management integrated and linking southwards to Whiteman Park through the resourced as key regional East Gnangara subarea tourism, recreation and • A preliminary set of ecological linkages have been conservation reserves. identifi ed in the heavily cleared area to the west 24. current native woodland be and north of Zone 6 to ensure connectivity with retained to protect biodiversity, bushland from Gnangara Park to bushland on the the top of the Gnangara Mound Dandaragan Plateau and north of Gingin Brook and the ‘window’ into the and Moore River and a linkage from Yanchep confi ned aquifers. National Park to the coast, and formalisation of a 25. the designation of a ‘wilderness’ linkage through Wilbinga to the Scarp to the east area centred on the Banksia • Six regional ecological linkages have been subarea, where access is limited identifi ed across the current pine plantation on to management access only, the East Yanchep subarea. Native vegetation should be considered. remaining under the pine canopy has not yet been 26. the GSS support the idea of assessed Ridges state forest, excluding • Two well protected vegetation complexes, the existing limestone mining (Bassendean and Karrakatta North Transition) leases, being incorporated occur largely within the Banksia subarea. into Yanchep National Park as Signifi cant areas of under-represented Spearwood soon as possible. An alternative Dunes (Cottesloe North and Karrakatta North) limestone resource has been occur in Zone 6 identifi ed north in the proposed • Yanchep National Park is of regional signifi cance 5 (1)(h) reserve in Wilbinga. for recreation, sense of place and conservation 27. further refi nement of the values. The caves, Loch McNess and associated ecological linkages across wetlands all depend on groundwater from the total the East Yanchep subarea catchment post-pine be undertaken. This • Rehabilitation of approximately 75 per cent of land should signifi cantly reduce back to bushland within these linkages is required. the rehabilitation cost of They link large areas of bushland in Gnangara approximately 75% of land Park to Yanchep National Park and help protect back to bushland within these under-represented vegetation complexes in the linkages. Spearwood Dune system
75 Zone 6 – West Yanchep, East Yanchep Gnangara Sustainability Strategy Appendix 1 Zone and Banksia subareas Gnangara groundwater system zone plans
July 2009
6.6 Recommendations to address water and land management issues in Zone 6
Management Issue Explanation Recommendations consideration
6.6.4.2 • Three threatened ecological communities occur It is recommended that: Threatened in Zone 6. Six occurrences of the critically 28. threatened fl ora, fauna and fl o r a , endangered Caves SCP 01 Aquatic Root Mat and ecological communities be fauna and a single Sedgeland SCP 9b site occur in Yanchep managed in accordance with ecological National Park. They are groundwater dependent the Wildlife Conservation Act communities • Numerous patches of the Limestone ridges SCP 1950 (WA), and the relevant 26a community occur in the proposed Ridges recovery plans for threatened extension to Yanchep National Park and further and priority species and north. They are threatened by clearing for mining ecological communities. operations and too frequent fi re with subsequent 29. where applicable, threatened weed invasion fl ora, fauna and ecological • There are three declared rare fl ora and 11 priority communities be managed fl ora in Zone 6. Lowering of the watertable and in accordance with the declining rainfall (due to climate change) are a Environment Protection and threat. Priority listed species also exist within the Biodiversity Conservation Act zone 1999 (Cwlth). • The pine plantation has been recognised as an important feeding and roosting area for Carnaby’s black-cockatoo for over 70 years. The pine plantations in the GSS study area limit groundwater recharge and will be harvested without replacement over the next 20 years. The expected clear-fall without replacement will possibly lead to a shortage of food for Carnaby’s black-cockatoo
76 Gnangara Sustainability Strategy Appendix 1 Zone 6 – West Yanchep, East Yanchep Zone Gnangara groundwater system zone plans and Banksia subareas
July 2009
6.6 Recommendations to address water and land management issues in Zone 6
Management Issue Explanation Recommendations consideration
6.6.4.3 • There are few effective options available for It is recommended that: Wetlands and managing some wetlands under drying climate 30. wetland biodiversity values and groundwater scenarios where there is either a long lag time wetland complexes be identifi ed dependent in groundwater recovery or no recovery, and/or and prioritised before and after ecosystems severe impact from acid sulphate soils pine removal. • The western wetlands in Yanchep National Park 31. the feasibility of maintaining are signifi cant. The area contains one wetland or recovering those wetlands of international and regional importance, Loch and groundwater dependent McNess which is listed in the Directory of ecosystems affected by important wetlands in Australia groundwater decline and acid • Yanchep Caves, where the continued lowering sulphate soils be determined. of groundwater and drying of cave streams are 32. further analyses of risks and threats to cave communities. Management actions cost-benefi ts of alternative to alleviate these threats include installation of management options be small and large scale watering systems undertaken. 33. an assessment be undertaken of the relative merits of the continued augmentation of wetlands in a drying climate compared with other alternative uses of groundwater. 34. signifi cant remaining wetlands and groundwater dependent ecosystems be monitored and protected from development. 35. it be determined whether there are any wetlands or groundwater dependent ecosystems that should be incorporated into any future review of ministerial criteria sites. 36. the GSS support the Department of Water’s groundwater investigation drilling programme to better delineate the area of connectivity between the Superfi cial and underlying confi ned aquifers. 37. the GSS support the current rewatering project for the Yanchep Caves in the medium term.
77 Zone 6 – West Yanchep, East Yanchep Gnangara Sustainability Strategy Appendix 1 Zone and Banksia subareas Gnangara groundwater system zone plans
July 2009
Figure 12 Zone 6 public water supply borefi elds
78 Zone 7 plan – Whitfords, Gwelup, Perth North and Cottesloe Peninsula subareas Zone 7 Gnangara Sustainability Strategy Appendix 1 Draft for public comment July 2009
7.1 O ve r v i ew Percentage of Subarea Land area ha total GSS area Zone 7 is highly urbanised with the main land uses being residential housing and associated Whitfords 14 805 6.9 commercial, recreational and industrial areas. This is the most urbanised zone and there are extensive Gwelup 1696 0.8 public water supply bores, particularly in the Gwelup subarea. When domestic backyard bores, Perth North 23 454 10.9 local government and industrial water abstraction Cottesloe 1256 0.6 is included, this zone uses about half of all Peninsula groundwater abstracted from the Gnangara system. Local governments There is signifi cant over-allocation of licensed water resources within the zone, although there may be Cities of Wanneroo, Subiaco, Nedlands, some water available in sections of the Perth North Fremantle, Stirling, Bayswater, Swan, Joondalup subarea provided urban wetlands are not affected, and Perth. Towns of Cambridge, Claremont, as they have been in recent drying winters. Bassendean, Cottesloe, Mosman Park and Vincent. Shire of Peppermint Grove. Small sections of Zone 7 are designated Priority 3 Water source protection areas in recognition of their Population in 2006 importance for providing drinking water supplies. Groundwater level declines of up to 4 metres Whitfords – 198 860, Gwelup – 23 279, Perth between 1974 and 2008 have occurred in areas of North – 370 049, Cottesloe Peninsula – 19 175 Gwelup and Perth North, affecting wetlands and Land form (surface geology) groundwater dependent ecosystems as well as water security. All bores including backyard bores Quindalup, Spearwood and Bassendean sands, near borefi elds need to be licensed. Tamala limestone, Swamp and lacustrine deposits (peat, peaty sands), Safety Bay sands Bush Forever sites, local bushland remnants and planned ecological linkages are located across all Wetlands subareas. The groundwater dependent features found across the zone have important social, cultural Herdsman Lake, Lake Monger, Lake Gwelup, and ecological values to the broader community. Lake Joondalup, Beenyup Swamp, Lake Goollelal, Wallubuenup Swamp, Carenlup Swamp, Perry Lakes, Lake Claremont, Star Swamp, Carine Swamps, Dog Swamp, Emu Swamp, Jackadder Lake
Indigenous sites of signifi cance
219, including Dog Swamp, Herdsman Lake, Bold Park, Lake Joondalup, Kings Park
79 Zone 7 – Whitfords, Gwelup, Perth North Gnangara Sustainability Strategy Appendix 1 Zone and Cottesloe Peninsula subareas Gnangara groundwater system zone plans
July 2009
7.2 Allocation status of Zone 7 • The current water management strategy in over allocated areas is to cap use (so no new licences are issued), reduce use The GSS zone and subarea boundaries differ from through effi ciency and recover water where the current water allocation management area licensing processes allow. boundaries used by the Department of Water. The Gnangara groundwater area is proclaimed in • A small volume of water is available accordance with s.26B of the Rights in Water and from some of the southern groundwater Irrigation Act 1914 (Figure 15). subareas.
As of December 2008 the licensed groundwater • There is no additional water available from allocation status for gazetted groundwater subareas the Leederville or Yarragadee aquifers in which fall within GSS Zone 7, is as follows (see Zone 7. Figure 13 ): Predicted continued reduction in recharge from rainfall will reduce water availability in future years. • The draft Gnangara groundwater areas Changes in current land use may alter this trend. management plan (2008) set allocation limits which indicate that most groundwater In Zone 7 the GSS recommends that the use of subareas in the Superfi cial aquifer are approximately 20 gigalitres per year of stormwater between 0.3 to 109 per cent allocated under and 64 gigalitres per year of treated wastewater the current climate and current land and outfall for direct use or for managed aquifer recharge water use.
Figure 13 Zone 7 2008 licensed groundwater allocation — 84.6 gigalitres
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be investigated. The GSS also recommended that 7. 4 O bje ct ive s public open space be managed with greater water use effi ciencies.Along with other licensed users, The objectives of the Gnangara sustainability water allocation for public open space be reduced strategy for Zone 7 are to: by around 20 per cent. Small declines in levels are likely to impact greatly on valuable urban wetlands so expensive augmentation actions may be viable. • determine required lake hydroperiods (seasonal amounts of water) and establish methods for their attainment In addition to the licensed use of water outlined above, it is estimated that approximately 26.1 • manage social acceptability of changes to gigalitres of water is abstracted from the Superfi cial the more signifi cant wetlands by providing aquifer for unlicensed use. Unlicensed use in Zone information and education 7 is predominantly through use of domestic garden bores, with limited stock and domestic use. • monitor and provide methods of addressing saltwater intrusion along all ocean and river boundaries, especially the Cottesloe 7.3 I s su e s Peninsula subarea
The most important issues that need to be • encourage and support urban infi ll with addressed within Zone 7: high density development that directs the resulting stormwater into the aquifer
• the growth in urban population and • promote water sensitive urban design in new development placing pressure on public developments water supplies • protect cultural values associated with lake • the risk of salt water intrusion along the and wetland systems coastal sections of the zone, with potential for upconing of saltwater in deep bores • manage public water supply including its quantity and quality • the moderate risks associated with acid sulphate soils when peat is disturbed and • educate the community about their role in dewatered through abstraction across the improving stormwater quality zone (as in the Stirling arsenic incident) • manage peaty soils associated with • the drying of urban wetlands which have wetlands to reduce the likelihood of land increasingly signifi cant cultural, social and subsidence and acid sulphate soil formation ecological importance in a drying climate • rationalise and improve the effi ciency of • the increased wastewater fl ows occurring when irrigation of public open space there is a requirement for sharply increased water reuse to meet state targets and a need • manage groundwater allocations to align to reduce demand for scheme water with net recharge rates
• managing both the quality and quantity • identify whether this zone can retain or of water in the lakes and their associated improve its existing biodiversity, social and vegetation and wildlife habitat functional values
• managing and encouraging effi cient water • manage quality and quantity in the usage in public open space Spearwood boundary lakes and vegetation and wildlife habitat • promoting water sensitive urban design and its uptake for developments. • protect bushland and improve linkages and biodiversity
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• manage and encourage private water use • implement aquifer replenishment using effi ciency and identify the potential for treated wastewater to increase and maintain stormwater and wastewater reuse groundwater levels
• encourage reuse options for water from the • identify, protect and monitor social and Subiaco wastewater treatment plant cultural values associated with water features which are likely to evolve over time.
7.5 Recommendations for the whole of Zone 7 with associated benefi ts and risks
Recommendations Benefi ts Risks
1. It is recommended that • Reduced impact on groundwater resources • Possible loss of social amenity due to opportunities for reducing • Less pumping reduces risks of saltwater reduction in irrigation areas for private licensed allocations and non- intrusion and public open space licensed use be investigated.
2. It is recommended that the • Increased groundwater levels allowing more • Possible increase in the risk of GSS support stormwater assured public and private open space contamination of groundwater infi ltration undertaken in irrigation • Capital costs of stormwater diversion the towns of Cottesloe and • Improved social amenity for local residents • Capital and running costs of the Mosman Park and encourage • Wetlands more likely to be retained in a infi ltration galleries uptake by other councils. drying climate • Reduces saltwater intrusion • Reduced ocean and beach pollution
3. It is recommended that water • Increased likelihood of retaining urban • Potential for increased risk of from the Subiaco wastewater wetlands in a drying climate using a climate- contamination of groundwater (managed treatment plant be used independent and growing water resource aquifer replenishment of treated either directly or to replenish • Increased opportunity for groundwater use wastewater already occurs into coastal aquifers. for public and private open space aquifers where there are no ocean • Improved social amenity for local residents outfalls – such as at Mandurah, Halls • Reduced risk of salt water intrusion into Head and Yanchep – with no ill effects.) coastal and estuarine aquifers • Capital and running costs for Subiaco • Assists the state to meet its reuse targets wastewater treatment plant may be high • The cost of treating water more than needed for its intended use
4. It is recommended that public • Maintenance of social values associated • Altered amenity and landscape open space be managed with with public open space • Insuffi cient capital available to establish greater water use effi ciencies • Reduced impact on groundwater resources initial infrastructure by incorporating hydrozones • Continued community opportunity for and ecozones. recreational activities • Reduced maintenance cost for local government – therefore economic benefi ts
5. It is recommended that the • Increased community awareness of • Economic cost of monitoring and Department of Water provide groundwater resources and the impacts of communicating information regular reports on groundwater pumping levels under urban areas as • Increased likelihood of local governments an incentive for backyard and diverting stormwater into the aquifer local government bore users • Regulators can receive policy and/or to improve their water use process response to reporting effi ciencies.
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7.6 Recommendations to address the water and land management issues in Zone 7
Management Issue Explanation Recommendations consideration
7.6.1 7.6.1.1 • Public water supply and bores (Figure 1. It is recommended that an investigation Public water supply Public water 14): be carried out into recharging the management supply o Zone 7 borefi elds: deeper aquifer with recycled water for Subarea: Whitfords Borefi elds: West potential long term use for public water Mirrabooka, Whitfords and one supply. This would reduce reliance on Yarragadee bore the Superfi cial aquifer for public water 2007–08 borefi eld abstraction was supply. 14.4 GL Subarea: Perth North Borefi elds: Mirrabooka, West Mirrabooka and six Yarragadee bores 2007–08 borefi eld abstraction was 19.3 GL Subarea: Gwelup Borefi elds: Gwelup and three Yarragadee bores 2007–08 borefi eld abstraction was 21.6 GL • Abstraction by aquifer: Superfi cial 14.25 GL, Mirrabooka 2.79 GL, Leederville 13.18 GL and Yarragadee 25.00 GL
7.6.1.2 • The predicted continued reduction in It is recommended that: Stormwater net recharge from rainfall will reduce 2. funding be provided for continued trials and treated water availability in future years of managed aquifer replenishment to wastewater although urban infi ll and the continued determine its effectiveness in preventing recycling redirection of stormwater into river and salt water intrusion and increasing ocean outfalls into the aquifer may recharge. partially offset the decline in local areas 3. the potential for reuse and capture of • Major redirection of treated wastewater the current 50 GL of treated wastewater offers a feasible solution to declining outfall from the Beenyup and Subiaco groundwater levels and the continued wastewater treatment plants is loss of wetlands and groundwater for investigated. A further 14 GL will be local government and backyard use available by 2030. • The experiences of the towns of 4. the use of recycled water to maintain Cottesloe and Mosman Park to groundwater levels in the Floreat and better use the approximately 18 GL of Wembley areas be trialled by the stormwater in the urban main drains installation of galleries below Perry currently going to ocean and river Lakes. outfalls can be used as case studies. 5. the feasibility of increasing groundwater An unquantifi able amount of stormwater levels and use of groundwater from the is currently being discharged from local Mosman Peninsula be reassessed in government drains which could provide light of recent data on improvements to further opportunities water quality from the Floreat and Halls Head infi ltration trials. 6. the diversion of stormwater be extended to aquifers and to coastal and riverine local governments.
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7.6 Recommendations to address the water and land management issues in Zone 7
Management Issue Explanation Recommendations consideration
7.6.1.3 It is recommended that: Treated 7. funding continue to be provided for wastewater to trials of managed aquifer replenishment aquifer with to provide a long-term drinking water managed source. aquifer 8. alternative uses of Beenyup wastewater replenishment be considered if, for some reason at Beenyup (economic, social, or technical), the trial indicates that the method is not feasible. Options for infrastructure need to be identifi ed so that this valuable water source is not stranded.
7.6.1.4 It is recommended that: Water 9. all new developments adopt sensitive water sensitive design principles urban design which incorporate the sustainable management and integration of the quantity and quality of stormwater, wastewater, local groundwater and drinking water supply into urban design. 10. community bores be considered in areas where individual groundwater abstraction is affecting wetlands and groundwater dependent ecosystems, or where there is a high risk of saltwater intrusion or acid sulphate soil development.
7.6.1.5 • The saltwater interface in the Superfi cial It is recommended that: Saltwater aquifer extends up to a kilometre inland 11. the GSS support the development of a intrusion from the coast and around the Swan saltwater intrusion model and apply it to Estuary, and extends beneath the this zone. Cottesloe Peninsula subarea (between 12. monitoring of salinity levels in bores the Swan Estuary and the ocean) continue. • In some areas bores along the coast and around the river experience seasonal increase in salinity levels that are due to intrusion and upconing – vertical movement of the interface beneath the bore. This problem was most severe in the late 1970s and early 1980s after a series of below rainfall years which are more likely to occur under a drier climate • Cottesloe Peninsula is subject to salt water intrusion risks each summer and autumn
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7.6 Recommendations to address the water and land management issues in Zone 7
Management Issue Explanation Recommendations consideration
7.6.2 7.6.2.1 • The quality, variety and accessibility of It is recommended that: Land use Public open public open space is important for the 13. public open space be managed management space physical, mental and social wellbeing, of with greater water and nutrient use communities. Currently 39 GL of water effi ciencies by encouraging local is used to irrigate public open space government to: across the GSS study area. • monitor water use • Approximately 15.9 GL is used to • maintain water effi cient irrigation irrigate public open space in this zone systems (see Figure 13) • develop best practice systems • redevelop public open space using hydrozones and ecozones. 14. along with other licensed users, water allocation for public open space be reduced by around 20 per cent. This will be achieved by adopting best practice technology and improved water effi ciencies. 15. where local government or other parties have increased recharge through investing in the use of stormwater and treated wastewater, this is taken into account in their seasonal allocation.
7.6.2.2 • There are several acid sulphate soil 16. It is recommended that monitoring and Acid sulphate disturbance risks in Zone 7, associated investigation of potential acid sulphate soils with peaty soils in lakes and wetlands soils be undertaken. • In the early 2000s the disturbance of peaty soils in the Stirling Gardens area resulted in the release of acidic waters containing very high concentrations of arsenic resulting in the death of lawns and gardens using down-gradient groundwater
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7.6 Recommendations to address the water and land management issues in Zone 7
Management Issue Explanation Recommendations consideration
7.6.3 7.6.3.1 • The GSS supports the work done by It is recommended that the GSS provide: Biodiversity Bushland Bush Forever and the Perth Biodiversity 17. continued support for the remnants and Plan on identifying patches of intact implementation of Bush Forever ecological remnant bushland, wetlands and and the Perth Biodiversity Plan linkages ecological linkages for retention in this recommendations and protection of extremely developed zone of the GSS Bush Forever areas. study area 18. support for local government • The remnant vegetation has been biodiversity planning and its heavily cleared for urban development, implementation, to protect the bushland, previous agricultural and industrial wetland and ecological linkages in the development in this urban zone urban landscape. • The opportunities for protection of the small and highly fragmented bushland remnants in this zone are limited, although a number have been identifi ed as regionally signifi cant by Bush Forever. All remnants are at risk of becoming further fragmented from linear services (such as powerlines and roads) and are under threat of degradation from burning, weeds and feral animals including domestic cats and dogs • Several vegetation complexes that are under-represented in the formal conservation estate occur in this zone. Although opportunities for additional protection are limited, even small remnants have signifi cant conservation values if well managed. Key landforms are the coastal heaths on the Quindalup Dunes, vegetation complexes on the yellow Spearwood soil types (Cottesloe Central and South and Karrakatta Central and South) and the wetland Herdsman Complex • Bush Forever (WAPC 2000) and the Perth Biodiversity project (WALGA 2004) identifi ed 12 regional ecological linkages across this zone. The GSS has not sought to add to these due to the constraints in this urban landscape
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7.6 Recommendations to address the water and land management issues in Zone 7
Management Issue Explanation Recommendations consideration
7.6.3.2 • Two threatened ecological communities It is recommended that: Threatened are present in this zone: 19. threatened fl ora, fauna and ecological fl o r a , f a u n a o SCP 20a Banksia attenuata communities be managed in accordance and ecological community: A diverse Banksia with the Wildlife Conservation Act 1950 communities community restricted to urban Perth (WA), and the relevant recovery plans that is threatened by continued for threatened and priority species and development pressure, degradation ecological communities. and lowering of the groundwater 20. where applicable, threatened fl ora, levels fauna and ecological communities o SCP 30a Callistris preissii woodlands be managed in accordance with the community: A coastal community Environment Protection and Biodiversity that is highly cleared or degraded by Conservation Act 1999 (Cwlth). burning that once occurred along the coast, on islands and along the shore of the Swan River. Only very small isolated stands remain • Three species of declared rare fl ora and seven priority fl ora species are found in this zone and are currently protected. The impacts of hydrological changes on threatened fl ora are largely unknown • Priority listed mammals are known to occur within this zone. The wetlands within this zone provide important breeding sites for remnant frog populations
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7.6 Recommendations to address the water and land management issues in Zone 7
Management Issue Explanation Recommendations consideration
7.6.3.3 • There are few effective options available It is recommended that: Wetlands and for managing some wetlands under 21. changing wetland biodiversity values groundwater drying climate scenarios where there and wetland networks be identifi ed dependent is either a long lag time in groundwater and prioritised in the context of climate ecosystems recovery or no recovery and/or impact change and variability. from acid sulphate soils 22. the feasibility of maintaining or • This zone contains signifi cant recovering wetlands affected by high quality wetlands, lakes and groundwater decline, using treated groundwater dependent ecosystems. wastewater, be determined. Examples Their relative importance is increasing include the trialling of infi ltration galleries because non-urban wetlands supported for Subiaco wastewater treatment by groundwater that are not able to be plant water in the Perry Lakes area and supported by additions of stormwater diversion of the Floreat and Subiaco and/or treated wastewater continue to main drains in the Superfi cial aquifer. dry out and lose their aquatic values 23. further analyses of risks and cost- • The wetland chain along the eastern benefi ts of alternative management edge of the Spearwood Dune system options be undertaken. is of particular social and conservation 24. the feasibility of providing groundwater interest (in Yellagonga Regional Park, credits to local governments that divert Herdsman Lake Regional Park, Lake their local drainage water into the aquifer Monger and associated wetlands be investigated. around Gwelup through to Perry Lakes). 25. an assessment of environmental Inter-dunal wetlands parallel and close supplementation versus other water to the coast are also being lost and uses be carried out. should be retained where possible 26. remaining wetlands and groundwater • Important breeding populations of long- dependent ecosystems be monitored necked tortoises (Chelodina oblonga) and protected from development. and waterfowl (such as the Black Swan) 27. it be determined whether there are any use these wetlands as refugia following wetlands or groundwater dependent the loss of inland and other coastal ecosystems that should be incorporated wetlands into any future review of ministerial • The management of the Swan River criteria sites. and its associated wetlands is not addressed in this report as it is being managed by the Swan River Trust. However, it should be noted that the use of the estuary by waterfowl may be reduced because of a decrease in fresh surface water sources, such as springs, for birds
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Figure 14 Zone 7 public water supply borefi elds
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Figure 15 Department of Water gazetted groundwater subareas
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91 Appendix 1 Draft for public comment Gnangara groundwater system zone plans
July 2009 ISSN 1836-1528 (print) ISSN 1836-1536 (online) ISBN 978-1-921508-43-8 (print) ISBN 978-1-921508-44-5 (online)
Looking after all our water needs
Department of Water 168 St Georges Terrace, Perth, Western Australia PO Box K822 Perth Western Australia 6842 Phone: 08 6364 7600 Fax: 08 6364 7601 www.water.wa.gov.au