WESROC Regional Strategy for Management of …...4.2.3 Southern River Urban Water Management Study 14 4.3 WATER QUALITY STANDARDS AND CRITERIA FOR WESROC 15 5. DEVELOPMENT OF REGIONAL

Western Suburbs Regional Organisation of Councils

Regional Strategy for Management ofStormwater Quality

Volume 1 – Study Report

JDA Consultant HydrologistsMay 2002

JDA Regional Strategy for Management of Stormwater Quality

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CONTENTS

1. INTRODUCTION 11.1 BACKGROUND 11.2 STUDY OBJECTIVES 1

2. STUDY AREA CHARACTERISTICS 22.1 LOCATION AND TOPOGRAPHY 22.2 CLIMATE 22.3 GEOLOGY AND SOILS 22.4 SURFACE DRAINAGE 32.5 GROUNDWATER 32.6 WETLANDS 32.7 LAND USE 4

3. WATER QUALITY DATA COLLATION AND REVIEW 53.1 LOCAL AUTHORITY STORMWATER & WATER QUALITY STUDIES 53.2 WATER & RIVERS COMMISSION DATA 103.3 ROAD RUNOFF WATER QUALITY DATA 103.4 CURRENT GPT MONITORING PROGRAMS 10

4. WATER QUALITY STANDARDS & CRITERIA 114.1 NATIONAL WATER QUALITY MANAGEMENT STRATEGY 11

4.1.1 Australian & New Zealand Guidelines for Fresh and Marine Water Quality 114.1.2 Australian Guidelines for Urban Stormwater Management 124.1.3 Australian Guidelines for Water Quality Monitoring and Reporting 124.1.4 State Water Quality Strategy Framework for Implementation 13

4.2 WESTERN AUSTRALIAN REFERENCE DOCUMENTS 134.2.1 A Manual for Managing Urban Stormwater Quality in Western Australia 134.2.2 Swan Canning Cleanup Program Action Plan 134.2.3 Southern River Urban Water Management Study 14

4.3 WATER QUALITY STANDARDS AND CRITERIA FOR WESROC 15

5. DEVELOPMENT OF REGIONAL DRAINAGE PLANS 165.1 GENERAL 165.2 TOWN OF CLAREMONT 175.3 TOWN OF CAMBRIDGE 185.4 TOWN OF COTTESLOE 195.5 TOWN OF MOSMAN PARK 205.6 CITY OF SUBIACO 215.7 CITY OF NEDLANDS 225.8 SHIRE OF PEPPERMINT GROVE 235.9 WESROC REGIONAL OVERVIEW 23

6. IDENTIFYING PRIORITY SUB CATCHMENTS 276.1 METHODOLOGY 276.2 ESTIMATING NUTRIENT INPUT 27

6.2.1 Nutrient Input Decision Support System (NiDSS) 276.2.2 Application to WESROC Area 28

6.3 QUALITATIVE ASSESSMENT OF OTHER POLLUTANTS 286.4 LOCAL AUTHORITY PRIORITY CATCHMENTS 286.5 WESROC REGIONAL PRIORITY CATCHMENTS 29

7. STORMWATER QUALITY MANAGEMENT IN THECONTEXT OF WATER RESOURCES MANAGEMENT 307.1 CURRENT TRENDS IN STORMWATER MANAGEMENT 307.2 WATER QUALITY MANAGEMENT OPTIONS 307.3 COST BENEFIT EVALUATION OF MANAGEMENT OPTIONS 317.4 WATER RESOURCES PERSPECTIVE 34

8. PROPOSED STRATEGY 358.1 OBJECTIVES AND CRITERIA 358.2 THE STRATEGY 358.3 MONITORING 368.4 REVIEW 37


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9. IMPLEMENTATION PLANS 38

10. CONCLUSIONS/RECOMMENDATIONS 44

11. REFERENCES 50

LIST OF TABLES

1. LOCAL AUTHORITY STORMWATER AND WATER QUALITY RELATED STUDIES IN THE STUDY AREA

2. ANZECC (2000A) RECOMMENDED DEFAULT WATER QUALITY TRIGGER VALUES

3. CCP ACTION PLAN SHORT AND LONG TERM CATCHMENT WATER QUALITY TARGETS

4. TOWN OF CLAREMONT DRAINAGE OVERVIEW

5. TOWN OF CAMBRIDGE DRAINAGE OVERVIEW

6. TOWN OF COTTESLOE DRAINAGE OVERVIEW

7. TOWN OF MOSMAN PARK DRAINAGE OVERVIEW

8. CITY OF SUBIACO DRAINAGE OVERVIEW

9. CITY OF NEDLANDS DRAINAGE OVERVIEW

10. SHIRE OF PEPPERMINT GROVE DRAINAGE OVERVIEW

11. DRAINAGE DISCHARGE AREAS BY LOCAL AUTHORITY (% OF LOCAL AUTHORITY AREA)

12. DRAINAGE DISCHARGE AREAS BY LOCAL AUTHORITY (% OF TOTAL WESROC AREA)

13. DRAINAGE DISCHARGE AREAS BY LAND USE (% OF LAND USE AREA)

14. DRAINAGE DISCHARGE AREAS BY LAND USE (% OF TOTAL WESROC AREA)

15. POLLUTANT REMOVAL EFFICIENCIES FOR VARIOUS STRUCTURAL CONTROLS

16. POTENTIAL CONSTRAINTS FOR VARIOUS STRUCTURAL CONTROLS

17. WESROC IMPLEMENTATION PLAN

18. TOWN OF CLAREMONT IMPLEMENTATION PLAN

19. TOWN OF CAMBRIDGE IMPLEMENTATION PLAN

20. TOWN OF COTTESLOE IMPLEMENTATION PLAN

21. TOWN OF MOSMAN PARK IMPLEMENTATION PLAN

22. CITY OF SUBIACO IMPLEMENTATION PLAN

23. CITY OF NEDLANDS IMPLEMENTATION PLAN

24. SHIRE OF PEPPERMINT GROVE IMPLEMENTATION PLAN

APPENDICES

1. WATER QUALITY GUIDELINES FOR TOXICANTS

2. TABULATION OF SUB CATCHMENT LAND USE CHARACTERISTICS

3. NUTRIENT INPUT DECISION SUPPORT SYSTEM MODELLING

4. PRIORITY SUB CATCHMENT CALCULATIONS

5. NEW SOUTH WALES EPA EDUCATION CAMPAIGN MATERIAL EXAMPLES


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LIST OF FIGURES (Volume 2)

1. LOCATION MAP / STUDY AREA

2. TOPOGRAPHY

3. ANNUAL AND MONTHLY RAINFALL

4. ENVIRONMENTAL GEOLOGY MAP

5. MAXIMUM RECORDED GROUNDWATER LEVEL CONTOURS (VIA WRC GROUNDWATER ATLAS)

6. CONSERVATION CATEGORY WETLANDS AND BUSH FOREVER SITES

7. WRC MONITORING SITES

8. PRIMARY AND SECONDARY ROAD NETWORK

9. TOWN OF CLAREMONT LAND USE

10. TOWN OF CLAREMONT SUB CATCHMENTS

11. TOWN OF CAMBRIDGE LAND USE

12. TOWN OF CAMBRIDGE SUB CATCHMENTS

13. TOWN OF COTTESLOE LAND USE

14. TOWN OF COTTESLOE SUB CATCHMENTS

15. TOWN OF MOSMAN PARK LAND USE

16. TOWN OF MOSMAN PARK SUB CATCHMENTS

17. CITY OF SUBIACO LAND USE

18. CITY OF SUBIACO SUB CATCHMENTS

19. CITY OF NEDLANDS LAND USE

20. CITY OF NEDLANDS SUB CATCHMENTS

21. SHIRE OF PEPPERMINT GROVE LAND USE

22. SHIRE OF PEPPERMINT GROVE SUB CATCHMENTS

23. WESROC DRAINAGE OVERVIEW

24. NUTRIENT INPUT BY TOTAL PHOSPHORUS

25. MAJOR ROADS BY DENSITY

26. COMMERCIAL/INDUSTRIAL AREAS BY PERCENTAGE

27. LOCAL AUTHORITY PRIORITY SUB CATCHMENTS

28. REGIONAL PRIORITY SUB CATCHMENTS

29. NIDSS MODELLING RESULTS FOR PHOSPHORUS INPUT REDUCTION

30. IMPACT OF EDUCATION CAMPAIGNS ON PHOSPHORUS INPUT REDUCTION


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Acknowledgements

JDA Consultant Hydrologists would like to thank the following participating local authorityrepresentatives for their contribution toward the preparation of the WESROC Regional Strategyfor Stormwater Management :

Alex Douglas (City of Subiaco)

Geoff Eves (City of Nedlands)

Richard Watson (Town of Cambridge)

Wayne Le Guay (Town of Claremont)

Malcolm Doig (Town of Cottesloe)

Martyn Glover (Town of Mosman Park)

Graeme Simpson (Shire of Peppermint Grove).


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Executive Summary

The Western Suburbs Regional Organisation of Councils (WESROC) comprises of the localgovernments of the Cities of Nedlands and Subiaco, Towns of Claremont, Cottesloe andMosman Park, and the Shire of Peppermint Grove. The Town of Cambridge while not a formalmember of WESROC is also a contributing participant for this study.

Together with the Swan River Trust, Water & Rivers Commission and the Department ofEnvironmental Protection, WESROC identified the need for better management of stormwaterquality and a need to address the associated strategic issues on a broad catchment basis.

To achieve a comprehensive approach to the management of stormwater, a regional strategyfor management of stormwater quality has been developed. The Strategy draws together issuesconcerning the collection and disposal of stormwater with the aim of managing the quality ofstormwater discharging into the Swan River, Indian Ocean, local wetlands, and the groundwatersystem, to provide a framework for a coordinated approach to improving stormwater quality.

The Strategy

Given the current lack of a clear set of criteria or objectives set at the State Government levelfor urban stormwater management, local authorities and groupings such as WESROC have adegree of flexibility in the type of strategy to be developed and implemented.

To this end, it is recommended that the strategy view stormwater quality management within thecontext of the broader management of water resources on the Swan Coastal Plain. Thisstrategy therefore presents a holistic water resources management approach with a broaderfocus to include water resources aspects rather than purely the treatment of stormwater qualityto a certain, undefined, standard.

Recent developments in urban stormwater quality management have seen a shift of emphasisfrom attempts to trap or retard pollutants in their journey from land application to estuarydischarge, to a more fundamental “Prevention is better than Cure” philosophy. This proposedshift in emphasis from treatment to prevention, is taking place also in other Australian states.

WRC’s A Manual for Managing Urban Stormwater Quality in Western Australia (1998) iscurrently under review and the revised document will provide a greater emphasis onstrengthening source controls and catchment management measures to reduce pollutant input,while still incorporating previously accepted water sensitive urban design (WSUD) measuresand best management practice treatment trains.

The strategy recommended for WESROC follows this approach and considers source controltechniques to be vital to achieving stormwater quality improvements. The proposed strategy ismindful of the financial costs to local authorities and communities of stormwater qualitymanagement and has been developed accordingly.

To this end the strategy recommends the use of education campaigns, native plantings, andstreet sweeping as preferred comparatively low cost methods of reducing nutrients andpollutants and protecting receiving environments. Many local authorities already undertake co-ordinated street sweeping programs, and in many instances previous lake management andenvironmental plans have highlighted the need for public education as a major influence ofstormwater quality. Where possible, integration with existing programs is recommended.

In terms of Gross Pollutant Traps (GPT’s), these will still be required in certain instances as partof applying a treatment train approach. The need for GPT’s will require assessment on a caseby case basis. Given the number of discharge locations, and the significant cost of installationand maintenance of these units it is recommended some monitoring of stormwater quality beundertaken prior to installation to first determine whether a GPT is required at all, and secondlythe most suitable to install to meet the water quality requirements of the receiving environment.


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Given WESROC’s established nature and their high land requirement, and capital andmaintenance costs, the use of Water Pollution Control Ponds (WPCP) is not considered a viablealternative and are not recommended.

The strategy has identified priority catchments at both a local authority and regional scale, and itis recommended these priorities be used as a basis for ongoing works on stormwater qualitywithin the region. A number of priority catchments drain to Water Corporation Main Drainage.Negotiation with Water Corporation regarding any works for these catchments will be requiredon a case by case basis.

With regard to new development, infiltration of stormwater on site should be encouraged.

In terms of water resources management, discharge of stormwater to the Indian Ocean andSwan River via Water Corporation main drainage represents a major discharge from theWESROC area. These discharges primarily come from the 3 larger local authority areas ofSubiaco, Nedlands and Cambridge. There is therefore an argument for these three localauthorities to investigate opportunities to utilise these discharges from a potential waterresource and re-use perspective.

Implementation Plans

Implementation plans for individual authorities have been developed based on the top fewpriority catchments within each local authority with an emphasis on regional prioritysubcatchments. In many cases, priority catchments have already been targeted by the relevantlocal authorities for stormwater quality improvement measures and studies and/or infrastructurehave already been implemented.

These plans should be considered indicative only and subject to ongoing review by individuallocal authorities.

Table E1 : Summary of Implementation Plans

WESROC

Consider infiltration opportunities for drainage currently discharged to Indian Ocean and Swan River forpotential use as water resource

Encourage infiltration of new development, where practicable

Development and implementation of an integrated monitoring program targeting key catchments toestablish baseline stormwater quality data from which future water quality criteria can be established.

Facilitate annual review of implementation programs and assessment of priorities. Assessment / co-ordination of local authority implementation plans within the context of regional priority considerations andcross local authority boundary issues.

Facilitate review of stormwater quality strategy after 4 years :

assess success of measures implemented and programs undertaken. analysis of monitoring data collected to provide baseline data to define water quality criteria. integration of criteria and policy developments at the State Government level. review of new developments in stormwater quality management. further refinement of the strategy and reassess priority catchments for future works.

Individual Local Authorities

Development and implementation of education programs for residents of priority catchments Review existing street sweeping operations with stormwater management considerations, particularly

areas draining to Conservation Category Wetlands, river, and coastal discharge catchments Implement recommended actions for identified key Regional and Local Authority Priority Catchments

as specified in individual local authority implementation plans.

Monitoring


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It is recommended WESROC undertake an integrated monitoring program targeting keycatchments to establish baseline stormwater quality data from which future water quality criteriacan be established.

Stormwater inflow sites to be included in the monitoring program should be based on theidentified regional priority catchments, focussing on major discharges to the Indian Ocean andSwan River.

Review

Annual review of implementation programs is recommended. With regard to the Strategydocument itself, it is recommended the Strategy be reviewed after a period of 4 years. Thisreview process would include :

assessment of the success of measure implemented and programs undertaken.

analysis of monitoring data collected over this period to provide the baseline data to definespecific water quality criteria.

integration of criteria and policy developments at the State Government level.

review of new developments in stormwater quality management.

further refinement of the strategy and reassess priority catchments for future works.


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1. INTRODUCTION

1.1 Background

The Western Suburbs Regional Organisation of Councils (WESROC) comprises of the localgovernments of the Cities of Nedlands and Subiaco, Towns of Claremont, Cottesloe andMosman Park, and the Shire of Peppermint Grove. The Town of Cambridge although not aformal member of WESROC is a contributing participant for this study.

Together with the Swan River Trust, Water & Rivers Commission and the Department ofEnvironmental Protection, WESROC has identified the need for better management ofstormwater quality and the need to address the associated strategic issues on a broadcatchment basis.

To achieve a comprehensive approach to the management of stormwater, WESROC hasdeveloped a regional strategy for management of stormwater quality.

The Strategy draws together issues concerning the collection and disposal of stormwater withthe aim of managing the quality of stormwater discharging into the Swan River, Indian Ocean,local wetlands, and the groundwater system, to provide a framework for a coordinated approachto improving stormwater quality.

1.2 Study Objectives

Key objectives of the study are :

To details currently applicable water quality standards and criteria and identify possiblechanges that may impact on the collection, and disposal/treatment of stormwater inparticular environments. Based on these, appropriate objectives and criteria will also berecommended.

To provide a summary and review of water quality information which has been collected bylocal government and the relevant state agencies, and provide information regarding thesources and types of contamination in the region.

To develop an integrated program for water quality monitoring and information gathering.

To develop of a regional plan identifying catchment boundaries and the current drainagecollection systems in relation to existing stormwater discharge outlets.

To identify current trends and developments in the area of stormwater management,including possible causes and sources of contamination, collection system engineeringoptions, litter entrapment, nutrient stripping and disposal, stormwater re-use, andcommunity education.

To propose a range of options for various aspects of stormwater quality managementapplicable to the region.

To recommend a strategy and actions to achieve improvements to the management ofstormwater quality.

To develop implementation plans with each local government that will allows specificprojects to be advanced with appropriate integration with other local governments.


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2. STUDY AREA CHARACTERISTICS

2.1 Location and Topography

The Study Area comprises the local government authorities of Cambridge, Claremont,Cottesloe, Mosman Park, Nedlands, Subiaco, and Peppermint Grove

The Study Area is generally bounded by the Indian Ocean to the west, Kings Park and theMitchell Freeway to the east, Herdsman Lake to the north and the Swan River to the south(Figure 1).

The total Study Area is approximately 64.4 sq km. The Town of Cambridge and the City ofNedlands comprise over 65% of the total Study Area.

The topography is generally undulating, typically varying between 0 to 30 mAHD over most ofthe Study Area (Figure 2). There are some elevated area in the Town Of Cambridge’s Bold Parkwhich are in excess of 80 mAHD.

2.2 Climate

The Study Area has a Mediterranean climate with mild wet winters and hot dry summers.

It has a long term average annual rainfall of approximately 860mm (based on Bureau ofMeteorology Station, Perth Regional Office,1880 to present). Annual rainfalls are shown inFigure 3. The average annual rainfall for Perth has decreased significantly since the mid 1970’s.

Since 1975, the average annual rainfall has been 790 mm, representing an 8% reductioncompared to the long term average.

2.3 Geology and Soils

The environmental geology of the study area varies according to distance from the IndianOcean and the Swan River. Figure 4 presents the environmental geology of the Study Area aspresented by Gozzard (1986), and similar to the surface geology as mapped by Davidson(1995).

From Figure 4, it can be seen that the environmental geology of the Study Area ispredominantly comprised of calcareous Safety Bay Sand (S1 and S2) and sands derived fromTamala Limestone (S7). Davidson (1995) describes the Safety Bay Sand as occurring on thecoastal margin as eolian stable and mobile dunes, and sands from the Tamala Limestone as ofresidual origin.

Outcrops of Tamala Limestone (LS1) are also evident in the north and south western parts ofthe Study Area. Limestone along the coastal strip varies in thickness, depending mainly ontopography and has maximum thickness of 110m (Davidson, 1995). In much of the area wherethe limestone is not evidently exposed, it is overlain by a layer of mobile Safety Bay Sandtowards the coast and weathered sand from the limestone itself in other areas.

Figure 4 also shows the occurrence of pale grey to white sand (S14) along the south easternboundary with the Swan River, and a small pocket in Peppermint Grove. This sand is of alluvialorigin and occurs in areas where the shoreline is low lying and exposed.

Pockets of Peaty Clay (Cps) and Peat (P) are also evident. These areas are of lacustrine originand hence occur in low lying areas, usually in association with a wetland or open water body.


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2.4 Surface Drainage

Surface drainage within the Study Area comprises of a network of piped local drainage andWater Corporation Main Drainage, which feed to a variety of receiving bodies including:

Swan River

Indian Ocean

Lakes (Monger, Herdsman, Jualbup, Claremont, Mabel Talbot, Perry Lakes)

Compensating Basins

Infiltration Basins, Swales, Soakwells.

Surface drainage considerations vary widely throughout the Study Area. Detailed discussion onsurface drainage for individual local government authorities is presented in Section 5.

Field investigations of the existing stormwater drainage system were undertaken by JDAassisted by local government representatives in September and October 2001.

2.5 Groundwater

Perth Groundwater Atlas (WRC, 1997) provides maximum recorded groundwater contours forthe Perth metropolitan area based on the maximum recorded groundwater levels at WRC bores.

For the Study Area, maximum recorded groundwater levels vary from 1 mAHD near the coastand Swan River to 14 mAHD on the north east boundary at Lake Monger (Figure 5). Seasonalgroundwater variation on the Swan Coastal Pain is typically in the order of 1.0 to 1.5 m.

Based on the topography (Figure 5), much of the Study Area has considerable depth togroundwater and hence provides an opportunity for infiltration of surface drainage.

2.6 Wetlands

Conservation Category Wetlands (CCW’s) within the Study Area (Figure 6) are :

Perry Lakes (Town of Cambridge)

Lake Monger (Town of Cambridge)

Mabel Talbot (City of Subiaco)

Lake Claremont (Town of Claremont)

Pelican Point (City of Subiaco)

No CCW’s are located within the Towns of Cottesloe and Mosman Park, the Shire ofPeppermint Grove and the City of Nedlands.

All CCW’s apart from Pelican Point are part of the formal drainage network, and all lakes, withthe exception of Lake Claremont, are part of the Water Corporation’s Main Drainage System.

Other non conservation category wetlands within the Study Area include Lake Jualbup and theQE2 Medical Centre Lake.


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2.7 Land Use

The majority of land in the Study Area is urban with some pockets of commercial and industrialland associated particularly with town centres. Some large areas of public open space arelocated at Perry Lakes and Bold Park in the Town of Cambridge.

Most urban areas are well established, though there are some new development areas,including new subdivisions at Mount Claremont (City of Nedlands), Subi Centro (City ofSubiaco) and Minim Cove (Town of Mosman Park).

Further discussion on land use within individual local government authorities is presented inSection 5.


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3. WATER QUALITY DATA COLLATION AND REVIEW

3.1 Local Authority Stormwater & Water Quality Studies

Previous stormwater studies undertaken within the Study Area as provided by local authoritiesare detailed in Table 1. The majority of previous studies related to stormwater are quantityrather than quality related studies, with the exception of Perry Lakes and Lake Monger whichhave had a number of environmental studies undertaken, and both have current environmentalmanagement plans.

Most previous water quality monitoring studies undertaken by the Town of Mosman Park andTown of Cottesloe were undertaken to monitor irrigation bore salinities.

Overall, little data exists regarding stormwater quality within the Study Area. Most monitoringhas focused on sampling of the receiving environment water quality (Perry Lakes, Lake Mongeretc) rather than the quality of stormwater inflows.

For Lake Monger, the main nutrient inflows are from groundwater flow from adjacent infilledareas to the east of the lake and from surface drainage. Calibrated estimates of inflow nutrientloadings in the Water and Nutrient Balance Model of Lake Monger (Draft report, July 2001) were0.8 mg/L and 0.1 mg/L for total nitrogen and total phosphorus respectively. These estimatescompare with other water balance derived estimates by Martinick McNulty Pty Ltd (1998) of 1.47mg/L and 0.23 mg/L for average Kjeldahl nitrogen and total phosphorus respectively. Theseestimates of loadings are consistent with stormwater nutrient loadings presented in Tan (1992)for sandy soils of the Swan Coastal Plain based on a monitoring program on various Perthurban areas conducted in 1990-91.

No specific concentrations are reported for heavy metal inflow concentrations from stormwater,however the City of Perth’s Lake Monger Management Plan (1992) indicates heavy metalswithin Lake Monger are generally below criteria given for the protection of aquatic life, howeverwater entering through stormwater drainage is at concentrations up to 100 times greater thanrecommended values.

Current local authority stormwater quality monitoring programs are discussed in Section 3.4


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Table 1 : Local Authority Stormwater and Water Quality Related Studies in the Study Area

Document Monitoring Data Document Summary / Key Points

Town of CambridgePerry Lakes EnvironmentalManagement Study, April 1992(Dames & Moore)

Perry Lakes Water Levels to1992, and Water Quality forSep-Nov 1991

Description of physical, chemical and biologicalenvironment. Provided options for managingwater levels. pH varies between 5.5 to 10.5, totalphosphorus concentration varies between <0.01mg/L and >0.10 mg/L. Recommends that eastlake be topped up with bore water to maintain apermanent water body and west lake be allowedto dry naturally

Lake Monger Management PlanPart I – Background, 1993-1998,November 1992 (City of Perth)

- Documents the history of Lake Monger Reserve,the physical nature of the present reserve, itshuman aspects eg. use, landscape andmanagement practices, and implications forfuture management

Lake Monger Management PlanPart II – Plan for Management,1993-1998, November 1992(City of Perth)

- Addresses issues associated with surroundingland use, aboriginal issues, the lake, fauna,recreation use, access, the landscape,maintenance, education/research, signs, reservearea/zoning. Objectives for each of these issuesestablished and recommendations presented,with priorities for implementation over 5 years

Lake Monger Rehabilitation PlanEast and South East Areas, March1995 (Regeneration TechnologyPty Ltd)

- Staged rehabilitation program over 5 years(1995-2000). Lake water quality identified aspoor. Objectives of plan to provide wildlifehabitats, and improve water quality. Strategiesoutlined in plan include (1) create nutrientstripping zones, (2) revegetation, (3) weedmanagement, (4) create habitat refuges, (5)encourage public appreciation and education,(6) construct pedestrian amenities, and (7)monitor progress. Includes detailed plans forrevegetation and recontouring of lake edge

Perth Main Sewer RehabilitationStage 4, August 1996(Water Corporation)

Lake Monger Water Levels1959-1996

Report on work being completed as part of PerthMain Sewer Rehabilitation. Includes (1)arboricultural survey of trees along sewer routeand provision of guidelines for working aroundtrees, (2) landscape survey, and (3) geotechnicalsurvey

Contaminant Cycling in LakeMonger and its Implications forLake Management, October 1997,Honours Thesis (Daniel Pierce,UWA Department ofEnvironmental Engineering)

- Phosphorus concentration in the sediments ishigh. Recommends against dredging of lakesediments as heavy metals in the sediments willremain immobilised for a long period of time ifthe lake system is left as it is as the sedimentshave a very high retention capacity for thecontaminants investigated. Sediments rapidlyaccumulating and the lake may be filled withsediment in 40 years. Accumulation rate may bedecreased by reducing lake productivity

Lake Monger Physio-chemical &Nutrient Data collected since1997, Murdoch University

1997,98,99, 2001 nutrientdata for Lake Monger andLake Monger outlet . 1999,2000 & 2001 bacterial countresults for Lake MongerRehab. Site, Lake Mongerand Perry Lakes

Management of water dischargefrom Lake Monger to the SwanRiver, July 1998. (Swan RiverTrust)

- Proposal to re-route stormwater from nutrientstripping basin east of Lake Monger to theexisting outlet from the lake. Supported by SwanRiver Trust and the Town of Cambridge providedthe construction of the new pollutant strippingbasin incorporates best management practice tominimise pollution to the Swan River


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Table 1 (cont) : Local Authority Stormwater and Water Quality Related Studies in the Study Area


Lake Monger Groundwater StudyPhase 1, November 1998(Martinick McNulty Pty Ltd)

5 Monitor Bore Water Levelson south-eastern side (Aug97–Jul 98). Water Qualitysampling October 1997

Two sources of groundwater inflow to LakeMonger – discharge from the superficial aquiferand discharge from shallow landfill areas(perched above a layer of peat). Most significantinflows of nitrogen and phosphorus from shallowlandfill areas (8415 kg TKN/yr, 963 kg TP/yr),followed by stormwater inflows (1445 kg TKN/yr,226 kg TP/yr). N & P inflows from superficialaquifer not significant.

Report on Preliminary SiteAssessment, Geotechnical andContamination, Infilled Quarry,The Boulevard, City Beach,December 1999 (GolderAssociates Pty Ltd)

- Reports on laboratory testing of organochlorinepesticides, organophosphate pesticides,petroleum hydrocarbons, and metals (arsenic,cadmium, copper, chromium, lead, mercury,nickel, zinc) on samples from the upper layers ofbackfill. Report discusses soil contamination butdoes not refer to groundwater contamination

Perry Lakes EnvironmentalManagement Plan, September2000 (PPK Environment &Infrastructure)

pH from 5.5 to 10.5TDS : West lake 106-108mg/L, East lake 168-192 mg/L(August 1991)TP between 0.01 and 0.03mg/L (August 1991)Orthophosphate (historicmeasurements) <0.03 to 0.28mg/L – highest levels recordedon several occasions since1975. Nitrogen <5 mg/LBacteria counts(organisms/100 mL) for eachlake for 1987 & 1991. Countsmuch greater in 1987 than1991, the 1987 countscoinciding with a period of lowwater level.Heavy metals – Pb <0.01 mg/L(August 1991), Zn <0.05 mg/LOil & grease 3 – 4 mg/L(November 1991)Sediments: Phosphorus load –680 mg/kg to 1,100 mg/kg(Dames & Moore, 1992)Pb <10 mg/kg to 2,100 mg/kg,Zn 68 mg/kg to 426 mg/kg

Reports water quality generally acceptable andwithin range exhibited by other Perth wetlandsLakes have only been permanent water bodiessince 1962, when dredged. The managementplan recommended: (1) Computer modelling ofthe Perry Lakes sector of the unconfined aquifer(2) Water quality and lake level monitoringprogram to commence in 2000/2001 andcontinue for the life of the plan to 2005 (3)Feasibility and costing study for engineeringwater level management solutions (4) Installationof automatic irrigation systems in Perry Lakesand Alderbury St reserves

Lake Monger Water QualityReport, May 2001

2 sets of water samples from 5locations around the lakemonthly

High bacterial counts due to bird faecaldroppings – sufficiently high to be a public healthrisk. Water quality seems to be improving asrehabilitation progresses – peaks of severecontamination less frequent and lesser inconcentration, improved clarity of water, lessfrequent algae blooms, and smaller midgepopulation. Chemical analysis results submittedto Council by Murdoch Uni annually. Includestables of bacteria counts, plot of N concentration

Stormwater Drainage Information,2001/2002

Financial plan including allocation for drainageand street cleaning operating and capital costsfor financial years from 2001/2002 to 2005/2006Stormwater drainage connection policy and roadverge development and maintenance policyStreet sweeping, gully cleaning and sumpcleaning programmes


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Table 1 (cont) : Previous Stormwater Related Studies in the Study Area


Water and Nutrient Balance Modelof Lake Monger, Draft, July 2001

1997 to 2000 monthly waterlevel monitoring results.

1998 to 2000 water quality monitoring results.Monitoring bores – TN 1.4 to 54.3 mg/L, TP 0.07to 2.44 mg/L. Lake Monger – TN 0.77 to 3.55mg/L, TP 0.07 to 0.47 mg/L. Drain discharges –TN 1.5 to 2.0 mg/L, TP 0.03 to 1.1 mg/L.Drain discharge average concentrations – TN0.99 mg/L, TP 0.15 mg/L (via Martinick McNulty,1998)

City of NedlandsReview of Drainage Issues –Robert Street, Dalkeith, LeuraStreet, Nedlands, Mason Gardens,Nedlands & Drainage Sumps inNapier Street and Loftus Street,Nedlands (David Porter ConsultingEngineer, June 2000)

- Reports on: inspection of drainage issues, extentof problems, likely solutions and impacts onservices and propertyBasic plans showing broad catchments anddrainage assets (1:2500) provided by City ofNedlands. The drainage data generally giveslocation of structures and pipe systems butdoesn’t indicate levels or the status of landtenure where pipe systems run through property.Problems resulting from the age of the drainagesystem and the reduced effectiveness of theexisting soakwell disposal systems. Maintenanceprogram (cleaning & upgrading) required.Additional drainage sumps required to reducelocalised flooding.

Town of Mosman ParkBattling Salinity The HolisticApproach, 2001 (Town ofMosman Park)

Moisture monitoring conductedin Town of Mosman Park 1998to 2001 salinity levels: meansalinity varied between 1040and 1450 ppm with the max in1999. Peak salinity variedbetween 1700 and 2500 ppmwith the max in 1999

Discusses the issue of salinity associated withthe Town of Mosman Park water supply(superficial aquifer). Salinity managed bymaximising infiltration, minimising irrigationtimes, spreading the load across the aquifer, andimproving irrigation methods, resulting indecreased salinity since 1999.

Town of Mosman Park MasterDrainage Plan Stage 1 & 2,June 1989 (GHD Pty Ltd)

- Preparation of a drainage master plan detailingproposed stormwater drainage upgrades.

Town of CottesloeGroundwater and IrrigationSystems Rationalisation Report,1981 (Peter Buck, Irrigation &Drilling Consultant)

Bore salinity data for 7 bores.General period of record July1980 – April 1981

In 1981 most of Cottesloe’s water supplies(groundwater bores) between 1000 and 1500ppm total dissolved salts. Total dissolved saltshave been increasing on average between 100and 150 ppm each year. Recommendsmonitoring of electrical conductivity by portableEC meter

Drainage Basin Report, December1983 (Kent McDowall &Associates Pty Ltd)

- An overview of Cottesloe drainage to individualbasins (to 1983) including a description and anoutline of any problems associated with thedrainage network.

Town Centre Drainage Study,June 1984 (Kent McDowall &Associates Pty Ltd)

- Drainage plans and cost estimates for individualland areas in the Town of Cottesloe

Information on GroundwaterSalinity Readings, July 1987(Hydro-Plan Pty Ltd)

- Annual average salinity ranges:Harvey Field Bore – 1100 to 1450 ppmCottesloe Oval – 1100 to 1600 ppmGolf Club Bore – 1500 to 2150 ppmGolf Club Well – 2500 to 3350 ppm


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Table 1 (cont) : Previous Stormwater Related Studies in the Study Area


Groundwater Salinities on theCottesloe Peninsular, June 1990(Hydro-Plan Pty Ltd)

1981 to 1990 - regularmonitoring of groundwaterquality

3 processes controlling groundwater (bore)salinities (1) upconing through over-pumping, (2)seasonal decline in water table through longterm use, and (3) gradual salinisation of theaquifer through turbulent mixing and incompleteflushing. Recommendations – (1) reducepumping rates, (2) increase recharge to theaquifer, (3) alternative sources of water, and (4)reduce water use.

Groundwater Monitoring DataReview for the Town of Cottesloe,Nov 1994 (Hydro-Plan Pty Ltd)

1990-1994. 8 productionbores, 2 Seaview Golf Clubproduction bores

Plots of salinity readings between 1990 and1994, salinity increasing in 7 of the 10 bores

Drainage Study 1995 Part 1 –Introduction, Summary,Conclusions & Recommendations,Drainage PerformanceInvestigation, Proposed Works(Draft issued for comment)(McDowall Affleck Pty Ltd)

- Detailed investigation, by catchment and sub-catchment, of existing drainage in the Town ofCottesloe. Recommendations for improvementand estimated costs of proposed works.

Drainage Study 1995 Part 2 –Catchment Area Analysis(McDowall Affleck Pty Ltd)

- Spreadsheet calculations to accompany Part 1.Includes catchment ID number, basincomputations, catchment drainagecharacteristics, catchment areas andcharacteristics, pipe capacities.

Working File : Drainage General(Town of Cottesloe)

- Photos of drainage basins within the Town,information on rainfall events andcorrespondence relating to drainage

Working File : Parks Supervisors’sReports (Town of Cottesloe)

Jan 1995 – Jul 1999 monthlybore salinity recordsDec 1997 – Dec 1998 boreconsumption rates

Town of ClaremontLake Claremont Catchment LandInformation Study, December1995 (BJ Bunny, RJ Ruiz-Avila)

- Prepared for Lake Claremont ManagementCommittee and the Town of Claremont. LakeClaremont classified as hyper-eutrophic duringsummer due to high levels of nutrients. Aims toaddress management at a catchment levels notonly at the point of drainage entry to lake. 69%of catchment identified as Town of Claremontwith 31% from City of Nedlands

Lake Claremont Nutrient StrippingBasin, December 1995 (HalpernGlick Maunsell)

- Design of Nutrient Stripping Basin for HeritageField development. Reports soluble reactivephosphorus concentrations in lake measured as0.42 mg/L via research program in 1987-1988.

Lake Claremont Golf Course andEnvirons Review, November 1997(Tract WA Pty Ltd, Michael Coatesand Associates, Roberts DayGroup)

- Considers redevelopment potential of the LakeClaremont Golf Course and its environs to createa “recreational and lifestyle precinct”.

Town of Claremont LakeClaremont Policy Revised 1998

Water Authority of WAmonitoring programs 1970-1986 twice yearly of totalcoliforms, faecal coliforms,BOD, suspended solids, TDS,pH Nitrogen and heavymetals.Phosphorus, pH and 6 ions(1987-1988)Phosphorus at south end(1993 –96)All data in lake data

Recommendations for protection of LakeClaremont its water quality environs. Emphasison community education, source controls,catchment management, and monitoring.

Report on Recharge Basins withinthe Town, ~1990

- Location and description of each existingrecharge basin/sump. Recommendations forimprovements at each site.


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3.2 Water & Rivers Commission Data

The Water and Rivers Commission has 7 surface water and 54 superficial aquifer monitoringsites within the Study Area (Figure 7).

The 7 surface water sites are located at Mabel Talbot Lake, Kingston-Aberdare Lake, LakeClaremont, Lake Monger, Perry Lakes East and West, and Lake Jualbup. All sites have waterstorage level data, with records from Lake Claremont and Kingston-Aberdare Lake dating from1900’s. Water quality is monitored at one surface water site, Lake Claremont where it has beensampled biannually since 1981.

Of the 54 superficial aquifer monitoring sites 35 have water quality sampled, 19 have only waterlevels recorded. Water quality parameters measured at 5 bores located along the Swan Riverand ocean boundary of the Study Area, include TDS, conductivity and nitrate as NO3, withrecords from 1978. Conductivity is the only parameter measured at the remaining water qualitysites, with readings from 1992 to 1998.

3.3 Road Runoff Water Quality Data

From 1997 to 2001, JDA conducted on behalf of Main Roads WA, a monitoring program toassess the quality of stormwater runoff from road surfaces in Perth. Sampling at 20 sites wasconducted 5 times per year. While none of the sites are located within the Study Area, the datacollected by JDA indicated road sediment as a potentially significant source of heavy metals(Cu, Pb, Zn) to receiving wetlands.

The major roads network within the Study Area including primary roads, secondary roads andfreeways is shown in Figure 8. The density of major roads within the Study Area was used as anindicator of stormwater quality to assist in determining priority areas. This is further discussed inSection 6.

3.4 Current GPT Monitoring Programs

Monthly performance monitoring of gross pollutant traps (GPTs) and standard council gullies inthe Town of Mosman Park is currently being performed by JDA. This monitoring is being fundedby a Clean Seas Grant to reduce stormwater pollution of rivers and oceans, awarded to theTown of Mosman Park. This monitoring is being performed over a 2 year period from June 2001to May 2003. The results will provide an indication of the proportion of pollutants being trappedby the gullies and GPTs and the proportion passing through to the Swan River. Material trappedin the gullies and GPTs is being subsampled for laboratory analysis of the following pollutants:

Total nitrogen

Total phosphorus

Oil & grease

Chromium

Copper

Iron

Lead

Hydrocarbons

Preliminary analysis of monitoring results to date suggests that a large proportion of dry materialtravelling through the stormwater system is trapped by standard council gullies. Most of thematerial leaving the gullies is successfully trapped by the GPTs installed downstream, thereforeonly a minor portion is entering the Swan River at the monitored locations.

The Town of Cottesloe are undertaking similar monitoring of its GPT’s.


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4. WATER QUALITY STANDARDS & CRITERIA

Currently applicable standards and criteria for stormwater quality are ill-defined at the StateGovernment level in Western Australia. WRC are currently in the process of reviewing itsapproach to urban stormwater management and it is expected that the outcomes of this processwill provide a clearer definition of water quality standards and criteria to apply in urbanstormwater management.

This chapter presents a review of existing documentation, and provides some recommendationstoward establishing interim standards and criteria to apply to the Study Area.

4.1 National Water Quality Management Strategy

The National Water Quality Management Strategy (NWQMS) was introduced by theCommonwealth, State and Territory Governments in 1992 as a response to growing communityconcern about the condition of the nation’s water bodies and the need to manage them in anenvironmentally sustainable way. The Strategy has three main elements : policies, process, andguidelines.

The NWQMS guidelines consist of a series of 21 documents prepared by the Australian andNew Zealand Environment and Conservation Council (ANZECC) and Agriculture and ResourceManagement Council of Australia and New Zealand. Of these documents, three related to urbanstormwater quality management are :

Guideline 4 : Australian and New Zealand Guidelines for Fresh and Marine Water Quality

Guideline 7 : Guidelines for Water Quality Monitoring and Reporting

Guideline 10 : Guidelines for Urban Stormwater Management

Responsibilities for implementing the NWQMS falls across a number of West Australian stategovernment agencies including the Water and Rivers Commission, Environmental ProtectionAuthority (EPA), the Department of Environmental Protection (DEP), and the Health Departmentof Western Australia.

4.1.1 Australian & New Zealand Guidelines for Fresh and Marine Water Quality

The main objective of the Australian and New Zealand Guidelines for Fresh and Marine WaterQuality (ANZECC, 2000a) is to provide an authoritative guide for setting water quality objectivesrequired to sustain current, or likely future, environmental values (uses) for natural and semi-natural water resources in Australia and New Zealand.

Advice from the DEP (Kevin McAlpine, pers comm) states that this document has supersededthe Western Australian Water Quality Guidelines for Fresh and Marine Waters (EPA Bulletin711, 1993). As ANZECC(2000a) contains more site specific information than the previous 1992version of the same document, the DEP have indicated no separate Western Australian statedocument will be required.

While ANZECC (2000a) indicates that the guidelines are not intended to be directly applied tostormwater quality, they are applicable where stormwater systems are regarded as havingconservation value. Default trigger values (concentrations below which there is a low risk ofadverse biological effects) applicable for protection of aquatic ecosystems in south-westAustralia are presented in Table 2. These trigger values were derived from ecosystem data forunmodified or slightly-modified ecosystems, and are not based on any objective biologicalcriteria. It is recommended they should only be applied where site-specific values do not exist oruntil site-specific values can be derived.


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Table 2 : ANZECC (2000a) Recommended Default Water Quality Trigger Values

Ecosystem Type TP(mg/L)

FRP(mg/L)

TN(mg/L)

NOx(mg/L)

NH4+(mg/L)

pH(mg/L)

Upland River 0.02 0.01 0.45 0.2 0.06 6.5 – 8.0

Lowland River 0.065 0.04 1.2 0.15 0.08 6.5 – 8.0

Freshwater Lakes & Reservoirs 0.01 0.005 0.35 0.01 0.01 6.5 – 8.0

Wetlands 0.06 0.03 1.5 0.1 0.04 7.0 – 8.5

Estuaries 0.03 0.005 0.75 0.045 0.04 7.5 – 8.5

ANZECC (2000a) also provides water quality guideline trigger values for toxicants (includingmetals, pesticides, hydrocarbons, and industrial chemicals) to provide alternative levels ofprotection. Values are reproduced in Appendix 1 together with a decision tree to be applied inassessing toxicant levels.

The current NWQMS approach recommends moving away from relying solely on chemicalguideline values for managing water quality to the use of integrated approaches comprisingchemical specific guidelines coupled with water quality monitoring, direct toxicity assessment,and biological monitoring. This approach will help ensure that the water management focuskeeps in view the goal of protecting the environment and does not merely shift to meetingnumbers.

4.1.2 Australian Guidelines for Urban Stormwater Management

The Australian Guidelines for Urban Stormwater Management (ANZECC, 2000c), aims toprovide a nationally consistent approach for managing urban stormwater in an ecologicallysustainable manner, and provides details of current best practice in stormwater managementand planning in Australia. The document highlights the need for a more holistic approach tostormwater management which addresses issues of stormwater quality and aquatic ecosystemhealth, and recognises the environmental impacts of urbanisation, the linkages between landand water management and the importance of community values and involvement.

The document references the Australian and New Zealand Guidelines for Fresh and MarineWater Quality (ANZECC, 2000a) to provide water quality objectives, but acknowledges thatobjectives for urban stormwater management are complicated by :

water quality being affected by other pollution sources, such as point sources, agriculturalrunoff and sewer overflows

difficulties in establishing relationships between ambient water quality concentrations andwet weather stormwater discharges.

4.1.3 Australian Guidelines for Water Quality Monitoring and Reporting

The Australian Guidelines for Water Quality Monitoring and Reporting sets out an overallframework for the establishment of monitoring programs, and presents methods and routines forthe setting of monitoring objectives, study design, field sampling, laboratory analyses, dataanalysis and the reporting and dissemination of information.

Similarly to the Australian Guidelines for Urban Stormwater Management (ANZECC, 2000c), thedocument references the Australian and New Zealand Guidelines for Fresh and Marine WaterQuality (ANZECC, 2000a) to provide water quality objectives.


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4.1.4 State Water Quality Strategy Framework for Implementation

The State Water Quality Management Strategy (SWQMS) for Western Australia was launchedby the State Government in May 2001 and adopted the same principles set out in the NationalStrategy and proposed supporting strategies for implementation based on the nationalframework. The implementation framework for the SWQMS was drafted with the primaryobjective to ensure that an administrative structure for water quality management is establishedin Western Australia that is consistent with the NWQMS.

The framework for implementation is the first document of a series, which will ultimately form theWestern Australian SWQMS.

4.2 Western Australian Reference Documents

4.2.1 A Manual for Managing Urban Stormwater Quality in Western Australia

The Water and Rivers Commission’s A Manual for Managing Urban Stormwater Quality inWestern Australia was released in 1998 to define and describe in practical terms BestManagement Practices (BMP’s) to reduce pollutant and nutrient inputs to stormwater drainagesystems. The Manual also aimed to provide guidelines for the incorporation of water sensitivedesign principles into urban planning and design, which would enable the achievement ofimproved water quality draining to the Swan and Canning Estuary.

The document was released not as a statutory requirement, but to provide a guideline for bestplanning and management practices, and was intended for use not only by WRC, but also byother State and Local Government Authorities and sectors of the urban development industry.

The Manual does not provide details of design objectives and performance criteria forstormwater quality, and provides only a qualitative comparison of pollutant removal efficienciesand associated costs. The Manual also relies on the use of “in-transit” and “end of pipe”stormwater treatment rather than adopting a whole of catchment approach which includessource control measures.

WRC have recently commenced a major review of the Manual. The focus of the review is toincorporate BMP information on new products, and to critically review the approach ofattempting to treat large volumes of water from infrequent high rainfall events.

Until the Manual is updated, WRC has encouraged the use of “source control” and “in-transit”control as the primary approach for stormwater quality management.

4.2.2 Swan Canning Cleanup Program Action Plan

The Swan Canning Clean-Up Program (SCCP) Action Plan report was released by the StateGovernment in May 1999 following a five-year project to develop a program for the effectiveclean up of the Swan Canning river system. The Action Plan recommends key strategies toachieve the program’s goals of :

Public Health and Amenity.Algal blooms are to be kept at a level where there is no threat to public health and amenityand they are not a nuisance to the community. Toxic algal blooms are to be kept to aminimum.

Ecological Function.Water quality in the Swan Canning system is suitable for maintaining a healthy ecosystem.People can swim or catch fish at any time.

Catchments and Targets.Contaminants in stream runoff leaving the catchments are to be within set targets. Rural


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catchments are to be managed to be productive and profitable, and are attractive andaffordable places to live.

New Urban and Industrial Areas.Areas are to be designed so that discharges have reduced contaminant levels and meet settargets before entering rivers, while they still remain attractive, affordable places to live andproductive and profitable places to work.

Older Urban and Industrial Areas.These areas are to be modified over time to reduce contaminant levels so that drainagedischarges can meet set targets before entering the rivers.

Water Sensitive Design (WSD) and associated BMP’s are presented as the best practicalmethod for managing nutrient inputs to meet long term water quality objectives.

The Action Plan provides general maximum acceptable concentrations for short and long termcatchment water quality targets as shown in Table 3. The Action Plan also provides estimates ofnutrient loading and water quality targets for individual catchments of the Upper Swan, MiddleEstuary and Canning River areas, however specific estimates for the Lower Estuary whereWESROC discharges occur are not provided.

Table 3 : Swan Canning Cleanup Program Water Quality Targets

Water Quality Parameter 5 Year Target 20 Year Target

Total Phosphorus (TP) 0.2 mg/L 0.1 mg/L

Total Nitrogen (TN) 2.0 mg/L 1.0 mg/L

4.2.3 Southern River Urban Water Management Study

The Southern River/Forrestdale/Brookdale/Wungong Structure Plan Urban Water ManagementStrategy (UWMS) is a study recently completed by a Project Team lead by JDA ConsultantHydrologists on behalf of the Water & Rivers Commission. The approach to urban stormwaterquality management adopted in the UWMS marks a shift in WRC’s approach to themanagement of pollutant and nutrients on the Swan Coastal Plain in adopting a strategy basedon catchment management measures (using source control initiatives) rather than to rely purelyon engineering approaches.

Water quality criteria and objectives for the study area are based on an approach to firstdetermine existing water quality throughout the area (prior to and during the developmentphase) and then determining appropriate targets. The data gathered are used to statisticallydescribe current water quality including confidence intervals. Local expert knowledge togetherwith the broad ANZECC trigger values (Table 2) and SCCP Targets (Table 3) can then be usedto determine suitable water quality targets.

The advantage of this approach is that targets and restorative efforts can be matched andrefined over time. A disadvantage is that the installation of stormwater management and otherinfrastructure is usually a one-off exercise that does not lend itself well to incrementalimprovements over time.


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4.3 Water Quality Standards and Criteria for WESROC

The determination of water quality standards and criteria for an established area such as thatcovered by WESROC is not straightforward, particularly as no well established guidelinescurrently exist at the State Government level. Targets provided in Table 2 via ANZECC (2000a)are for application to un-modified or slightly modified ecosystems and do not readily apply tostormwater management. Similarly, no specific standards or criteria are established in WRC’sManual for Managing Urban Stormwater in Western Australia.

The most appropriate targets are considered to be provided in the Swan Canning CleanupProgram Action Plan which recommend targets for Total Phosphorus and Total Nitrogen asshown in Table 3.

The approach recommended for the establishment of criteria for water quality management forWESROC is based on first determining existing storm water quality in the area through thedevelopment and implementation of a monitoring program, then to use this data together withthe SCCP and ANZECC data to establish suitable water quality targets.

The establishment of targets without first determining existing storm water quality is notrecommended as this may lead to a perceived failure to meet targets that may not beachievable, and may also lead to the implementation of inappropriate pollution control measuresat cost to local community.

A four stage process is recommended for the establishment of water quality criteria :

Phase 1 : DevelopmentEstablishment of a suitable monitoring program

Phase 2 : MonitoringImplement monitoring program to establish baseline water quality data

Phase 3 : Target SettingBased on an assessment of monitoring program data and water quality objectives,determine criteria in terms of establishing achievable improvements.

Phase 4 : ComplianceMonitor compliance with established targets to allow an assessment of performance.

Details of the recommended monitoring program (Phase 1) is contained in Chapter 8 of thisstrategy report.


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5. DEVELOPMENT OF REGIONAL DRAINAGE PLANS

5.1 General

Regional drainage plans were developed for each local authority, providing detail of :

Sub catchment boundaries, and the interaction of drainage flows across local authorityboundaries. Sub catchment boundaries were determined using field inspection, existingdrainage detail, and topographic data as provided by local authorities.

Location of key drainage facilities, including infiltration basins, compensating basins, grosspollutant traps (GPT’s), Water Corporation Main Drainage. The plans also identify thelocation of key outlets to the Swan River and Indian Ocean.

Various drainage receiving environments and a quantification of the area within each localauthority contributing flow to each environment.

Names were assigned to each sub catchment for ease of reference in this document. Thenaming convention adopted is that the sub catchment prefix is based on the local authority intowhich it discharges (eg SU6 is a sub catchment crossing the boundary of Subiaco andNedlands, but its discharge point is in Subiaco, hence a prefix of SU adopted rather than NE).

Drainage receiving environments were classified into nine types as follows :

Lake : sub catchment drains to a lake without an outflow (eg CL2 to Lake Claremont)

River : sub catchment drains directly to Swan River

River via Compensating Basin : sub catchment drains to a compensating basins and then tothe Swan River (eg SU1 drains from Mabel Talbot to Lake Monger and then to the SwanRiver)

Ocean/Dunes : sub catchment drains directly to the Indian Ocean via either an ocean outletor to the dunes.

Ocean/Dunes via Compensating Basin : sub catchment drains to a compensating basin,then to the Indian Ocean, generally via Water Corporation Main Drainage ( eg SU5 drains toLake Jualbup, then via Water Corporation Main Drainage to Indian Ocean)

Infiltration Basin/Swale : sub catchment drains to an designated infiltration basin or swale(as identified by local authorities). Note that these sub catchments may also containsoakwells to infiltrate stormwater, however the predominant measure used to infiltrate isidentified as an infiltration basin or swale.

Soakwell : sub catchment infiltrates via a series of soakwells.

Parks/Reserves : sub catchment discharges into a park or reserve via a designated outletwithout the existence of a designated infiltration basin. This type of discharge is generallyrestricted to the Town of Cambridge where there are a series of these outlet types into BoldPark.

Railway Reserves : generally restricted to the Town of Cottesloe, where a series of existingoutlet pipes drain into the railway reserve.

A tabulation of individual sub catchment characteristics including catchment area, land use type,and discharge type is presented in Appendix 2.


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5.2 Town of Claremont

The Town of Claremont’s land use and drainage sub catchments are shown in Figures 9 and 10respectively.

Claremont residential areas are generally R20 or less dense with some higher density areas ofR25 to R40. The main commercial areas are located along Stirling Highway and the main towncentre located along Bay View Terrace. Only a small area of light industrial exists alongGraylands Rd. Claremont contains a number of educational institutions including MethodistLadies College, Scotch College, Christchurch Grammar, and Claremont Teachers College.

25 sub catchments were identified for the Town of Claremont, of which 16 drain to infiltrationbasins. These basins receive flow from approximately 35% of the total local authority area.

The two largest sub catchments, CL2 and CL21, cover approximately 54% of the total area.These two sub catchment drain directly to Lake Claremont (Conservation Category Wetland)and the Swan River respectively.

A summary of key drainage statistics is shown in Table 4. Claremont has considerablemovement of drainage flow across its local authority boundary with Nedlands, with 11 of its subcatchments receiving flow from Nedlands sub catchments, and Claremont contributing flow to 9Nedlands sub catchments.

Table 4 : Town of Claremont Drainage Overview

Local Authority Area (sq km) 4.9

Sub Catchments

Total

Sub Catchments Receiving External Flow

Sub Catchments Providing External Flow

25

11

9

Drainage Facilities

Infiltration Basins

Compensating Basins

River Outlets

Ocean Outlets

Gross Pollutant Traps

17 1

0

3 2

0

0

Main Discharge Types by Area(% of total local authority area)

1. Infiltration Basin/Swale

2. River

3. Lake

35%

29%

26%

Notes :1. Number of Infiltration basins shown includes Lake Claremont2. Main River Outlet is Water Corporation Main Drainage


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5.3 Town of Cambridge

The Town of Cambridge’s land use and drainage sub catchments are shown in Figures 11 and12 respectively.

Cambridge is divided into two main residential areas by Bold Park and Perry Lakes - a north-south strip along the coast and an east-west strip along Grantham and Cambridge St. Its maincommercial areas are located along Cambridge St, and at Floreat Forum. Cambridge has largearea of active recreation (Wembley Golf Complex) and passive recreation (Bold Park).

38 sub catchments were identified for the Town of Cambridge. Drainage systems vary from eastto west, with the eastern most sub catchments draining via Water Corporation Main Drainage toLake Monger and the Swan River, central sub catchments draining to the Indian Ocean viaHerdsman Lake and Perry Lakes, and the western sub catchments using infiltration. 17 of the38 sub catchments have infiltration basins, and 12 discharge to parks and reserves.

Most of the eastern and central catchment areas drain to conservation category wetlands.

Approximately 21% of the total local authority area drains to the Swan River (6% of which isuncompensated) and 25% to the Indian Ocean (and surrounding dunes) via Water CorporationMain Drainage. The remaining area is largely infiltrated, including 17% of the total area beingdischarged into parks and reserves.

A summary of key drainage statistics is shown in Table 5. Cambridge has considerablemovement of drainage flow across its local authority boundary and interacts with Nedlands,Subiaco and Stirling to the north. Lake Monger also receives inflow from the Town of Vincent. 8of Cambridge’s sub catchments receive flow from outside the local authority boundary.Cambridge contributes flow to 11 external sub catchments.

Table 5 : Town of Cambridge Drainage Overview


Sub Catchments

Total



41 1

8

11

Drainage Facilities

Infiltration Basins

Compensating Basins

River Outlets

Ocean Outlets


24 2

4

0

1 3

0



2. Ocean/Dunes via Compensating Basin

3. Parks/Reserve

4. River via Compensating Basin

31%

25%

17%

15%

Notes :1. includes 3 sub catchments which drain into City of Stirling2. Some sub catchments contain more than 1 infiltration basin3. Water Corporation Main Drainage Outlet


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5.4 Town of Cottesloe

The Town of Cottesloe’s land use and drainage sub catchments are shown in Figures 13 and14 respectively.

Cottesloe consists predominantly of residential areas of density R20 or less. The maincommercial areas are located on the eastern boundary at Napoleon St and along MarineParade at Cottesloe Beach. The Perth to Fremantle railway line occupies a significant areaalong the eastern boundary of the local authority. Recreation areas are generally active areassuch as golf courses and sports grounds.

46 sub catchments were identified for the Town of Cottesloe, based largely on previouscatchment mapping done by McDowell Affleck. Three type of drainage systems dominate –infiltration to basins and swales (27 sub catchments), discharge to the Indian Ocean and dunes(8 sub catchments), and discharge to the railway reserve (8 sub catchments). There are a totalof 16 outlets to the Indian Ocean and sand dunes of which 2 systems have 3 gross pollutanttraps (GPT’s).

Approximately 20% of the total local authority area drains to the coast while 57% is infiltrated inbasins and swales. 22% of the total area drains to the railway reserve.

A summary of key drainage statistics is shown in Table 6. Cottesloe’s drainage has littleinteraction with other local authorities. Only 2 sub catchments receive flow from outside the localauthority boundary, and Cottesloe contributes flow to only 3 external sub catchments.

Table 6 : Town of Cottesloe Drainage Overview


Sub Catchments

Total



46

2

3

Drainage Facilities

Infiltration Basins

Compensating Basins

River Outlets

Ocean Outlets


31 1

0

0

16

3 2



2. Ocean/Dunes

3. Railway Reserve

57%

20%

22%

Notes : 1. Some sub catchments contain more than 1 infiltration basin2. Some sub catchments contain more than 1 GPT


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5.5 Town of Mosman Park

The Town of Mosman Park’s land use and drainage sub catchments are shown in Figures 15and 16 respectively.

Mosman Park consists predominantly of residential areas of density R20 or less. The maincommercial areas are located on its western boundary along Stirling Highway. There are largerecreation areas, including the Chidley Point Golf Course and linear reserves along the SwanRiver foreshore.

39 sub catchments were identified for the Town of Mosman Park, based on previous catchmentmapping provided by the local authority. Drainage discharge from the area is heavily dominatedby infiltration which covers 74% of the total local authority area. 17% of the total area drains tothe Swan River, and of the 17 river outlets 2 have GPT’s installed.

A summary of key drainage statistics is shown in Table 7. Of the WESROC councils, MosmanPark’s drainage has the least interaction with other local authorities. Only 1 sub catchmentreceives flow from outside the local authority boundary, and it contributes flow to only 4 externalsub catchments. Interaction across local authority boundaries is with the Shire of PeppermintGrove and the City of Fremantle.

Table 7 : Town of Mosman Park Drainage Overview


Sub Catchments

Total



39

1

4

Drainage Facilities

Infiltration Basins

Compensating Basins

River Outlets

Ocean Outlets


281

0

17

0

4 2



2. River .

74%

17%

Notes :

1. Some sub catchments contain more than 1 infiltration basin2. Some sub catchments contain more than 1 GPT


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5.6 City of Subiaco

The City of Subiaco’s land use and drainage sub catchments are shown in Figures 17 and 18respectively.

Subiaco consists predominantly of residential areas of density greater than R20. The maincommercial areas are located along Hay St and Rockeby Rd. The Perth to Fremantle railwayline occupies a significant area in the centre and along the northern boundary of the localauthority. Recreation areas are generally active areas such as Subiaco Oval and Rosalie Park.

10 sub catchments were identified for the City of Subiaco. Unlike other local authorities, none ofSubiaco’s stormwater is infiltrated, and all is exported via Water Corporation drainage to either :

the Swan River uncompensated (4 sub catchments)

the Swan River via Lake Monger and Mabel Talbot Park (Conservation Category Wetlands)(2 sub catchments)

the Indian Ocean via Lake Jualbup and Cliff Sadlier Memorial Park (3 sub catchments)

The City contains 4 outlets to the Swan River, none of which have GPT’s. The City has installeda GPT on an inlet to Lake Jualbup.

Approximately 67% of the total local authority area drains to the coast while 31% drains to theSwan River.

A summary of key drainage statistics is shown in Table 8. 6 sub catchments receive flow fromoutside the local authority boundary (Cambridge and Nedlands), and Subiaco contributes flowto 2 external sub catchments.

Table 8 : City of Subiaco Drainage Overview


Sub Catchments

Total



10

6

2

Drainage Facilities

Infiltration Basins

Compensating Basins

River Outlets

Ocean Outlets


0

5 1

4 2

0

1



2. River

3. River via Compensating Basin

67%

19%

12%

Notes :1. 4 of the 5 compensating basins are part of Water Corporation Main Drainage.2. One outlet is Water Corporations Main Drainaqe


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5.7 City of Nedlands

The City of Nedlands land use and drainage sub catchments are shown in Figures 19 and 20respectively.

Nedlands main residential area is located in the south eastern corner of the local authority andincludes the suburb of Nedlands and Dalkeith. It also includes the residential areas ofSwanbourne and Mt Claremont. Its main commercial areas is located along Stirling Highway. Itcontains a large areas of non–residential land in its northern and western regions. These areasinclude the McGillivray Sports Complex, Challenge Stadium, Karrakatta Cemetary, ShentonPark Rehabilitation Hospital, Irwin Barracks, Subiaco Wastewater Treatment Plant and theWater Corporation Research Centre.

53 sub catchments were identified for the Town of Nedlands. Catchments were based onboundaries provided by the City (which were based on topographic divides) modified to accountfor the extent of existing piped drainage networks.

The majority of Nedlands is either infiltrated or discharges to the Swan River. 29 subcatchments are infiltrated to basins or swales representing 44% of the total local authority area.11 sub catchments (representing 17% of the total area) discharge directly to the Swan River.

Nedlands has a total of 33 infiltration basins and 12 river outlets, 1 of which has a GPT. It has 1ocean outlet which is a Water Corporation Main Drain.

A summary of key drainage statistics is shown in Table 9. Nedlands has the largest number ofsub catchments which lie across its local authority boundary, interacting with Cambridge,Subiaco, Claremont and Cottesloe. 15 sub catchments receive flow from outside the localauthority boundary, and Nedlands contributes flow to 19 external sub catchments.

Table 9 : City of Nedlands Drainage Overview


Sub Catchments

Total



53

15

19

Drainage Facilities

Infiltration Basins

Compensating Basins

River Outlets

Ocean Outlets


33 1

0

12

1 2

2



2. River


44%

17%

14%

Notes :1. Some sub catchments contain more than 1 infiltration basin2. Water Corporation Main Drainage Outlet


J2868r.doc 2327 May, 2002

5.8 Shire of Peppermint Grove

The Shire of Peppermint Grove’s land use and drainage sub catchments are shown in Figures21 and 22 respectively.

Peppermint Grove is the smallest of the local authorities in WESROC. It is bounded to the northand south by the Town of Claremont and Town of Mosman Park respectively . To the west it isbounded by Stirling Highway and to the east by the Swan River. The area is predominatelyresidential with a strip of recreation area along the river foreshore. The Shire also contains acommercial area along Stirling Highway.

6 sub catchments were identified for the Shire of Peppermint Grove. Catchments were based ontopographic divides modified to account for the extent of existing piped drainage networks.

The majority of Peppermint Grove is either infiltrated (55%) or discharges to the Swan River(43%). Given its size Peppermint Grove has a large number of outlets (10) to the Swan River

A summary of key drainage statistics is shown in Table 10. Peppermint Grove’s main drainageinteraction across its local authority boundary is with the Town of Mosman Park, with 4subcatchments lying across this boundary.

Table 10 : Shire of Peppermint Grove Drainage Overview


Sub Catchments

Total



6

3

2

Drainage Facilities

Infiltration Basins

Compensating Basins

River Outlets

Ocean Outlets


4

0

10

0

0



2. River

55%

43%

5.9 WESROC Regional Overview

Individual local authority drainage plans were collated to prepare a drainage overview map forthe whole of the WESROC area (Figure 23). Summary statistics were developed for variousdischarge types (Swan River, Indian Ocean, and Groundwater) at individual local authority leveland for various land use types. Results are presented in Tables 11 to 14.

Summarising the overall results :

45% of the total WESROC area lies in catchments which cross local authority boundaries

52.1% of the WESROC area was found to infiltrate stormwater, 20.7% to discharge to theSwan River, and 27.2% to discharge the Indian Ocean and dunes, largely via WaterCorporation Main Drainage.


J2868r.doc 2427 May, 2002

Dis-aggregating the 20.7% of the area which discharges to the Swan River, 6.9%discharges to the River via a compensating basin which provides some opportunity for pre-treatment of discharge. 13.8% discharges to the Swan River direct.

Infiltration basins and swales were found to be the most commonly adopted discharge typeaccounting for 37.0% of the total WESROC area.

Results from Table 11 with respect to individual local authority areas show there is considerabledifferences between individual local authorities drainage systems. The Town of Mosman Parkhas the highest proportion of area infiltrated at 82.6% ranging to the City of Subiaco whichinfiltrates less than 2% of its total area. Conversely, 67.6% of the total City of Subiaco area isexported to the Indian Ocean via Water Corporation Main Drainage while the Town ofClaremont has none. The City of Subiaco has the largest percentage of area which dischargesto the Swan River at 30.6%.

Table 12 shows the drainage discharge areas for local authorities presented in relation to thewhole of the WESROC area. This allows for interpretation of results in a regional context.Summarising key findings :

Almost half of the 13.8% of total WESROC area directly discharging to the Swan Rivercomes from the City of Nedlands. Although Claremont contributes 29.0% of its total area tothe Swan River, in a regional context this equates to only 2.3% of the total WESROC area

Almost 80% of the area which discharges to the Swan River via compensating basinscomes from the Town of Cambridge.

The City of Subiaco and Town of Cambridge provide the largest area contributions to flowwhich discharge to the Indian Ocean via compensating basins (7.5% and 8.7% of totalWESROC area respectively).

Of the 36.8% of total area which is infiltrated in basins and swales, the Town of Cambridgeand City of Nedlands are the largest contributors providing over 10% each of the totalWESROC area. While the Town of Cottesloe infiltrates 56.7% of its area into basins andswales and the Town of Mosman Park 74.5%, in a regional context this equates to a total ofonly 8.6% of the WESROC area.

The results highlight the need for management at both regional and local scales, particularlygiven the large variation in the size of local authorities. The results also highlight the importanceof the two large authorities (City of Nedlands, Town of Cambridge) toward achieving regionaloutcomes.

Summarising the key results from Tables 13 and 14 with respect to land use classifications :

Accumulating land use into 3 broad categories, residential areas comprise 51.2% of thetotal WESROC area, industrial/commercial 7.0%, and parks and recreation 41.8%.

Of the 20.6% of total area which drains to the Swan River, approximately 60% is residentialland. The majority of this residential land is R20 zoning or less dense, which is likely to havea higher nutrient input level than more dense residential development areas.

Only 1.7% of the total WESROC area is industrial land which drains to the Swan River.Approximately one third of this area drains directly to the Swan River.

Approximately 44% of the total industrial area is discharged to the Indian Ocean.

Almost half of all residential development is infiltrated.

Results are further interpreted in the development of priority sub catchments (Section 7), theIdentification of stormwater management options (Section 8), and the development of thestormwater quality strategy (Section 9).


J2868r.doc 2527 May, 2002

Table 11 : Drainage Discharge Areas by Local Authority (% of Local Authority Area)

Cambridge Claremont Cottesloe MosmanPark

Subiaco Nedlands PeppermintGrove

Total Area (sq km) 22.0 4.9 4.0 4.3 7.1 20.6 1.1

Swan River Discharge

River Direct (%) 5.9 29.0 0.9 16.8 18.8 17.3 43.4

River via Comp Basin (%) 15.1 0.0 0.0 0.0 11.8 1.1 0

Total (%) 21.0 29.0 0.9 16.8 30.6 18.4 43.4

Indian Ocean Discharge

Ocean/Dunes Direct (%) 6.5 0.0 19.9 0.6 0.0 10.4 0.0

Ocean/Dunes via Comp Basin (%) 24.7 0.0 0.0 0.0 67.6 13.5 0.0

Total (%) 31.2 0.0 19.9 0.6 67.6 23.9 0.0

Groundwater Discharge

Lake (%) 0.0 25.6 0.0 0.0 0.0 1.8 0.0

Infiltration Basin/Swale (%) 30.8 35.4 56.7 74.5 0.1 44.4 54.9

Soakwell (%) 0.0 6.7 0.9 2.2 0.0 4.2 0.9

Parks/Reserves (%) 17.0 0.0 0.0 3.3 0.0 6.5 0.0

Railway Reserve (%) 0.0 3.3 21.6 2.6 1.7 0.8 0.8

Total (%) 47.8 71.0 79.2 82.6 1.8 57.7 56.6

Table 12 : Drainage Discharge Areas by Local Authority (% of Total WESROC Area)

Cambridge Claremont Cottesloe MosmanPark

Subiaco Nedlands PeppermintGrove

Total

Total Area (sq km) 22.0 4.9 4.0 4.3 7.1 20.6 1.1 64.0


River Direct (%) 2.1 2.3 0.1 1.1 2.0 5.5 0.7 13.8

River via Comp Basin (%) 5.3 0.0 0.0 0.0 1.3 0.3 0.0 6.9

Total (%) 7.4 2.3 0.1 1.1 3.3 5.8 0.7 20.7


Ocean/Dunes Direct (%) 2.3 0.0 1.2 0.0 0.0 3.3 0.0 6.8

Ocean/Dunes via Comp Basin (%) 8.7 0.0 0.0 0.0 7.5 4.2 0.0 20.4

Total (%) 11.0 0.0 1.2 0.0 7.5 7.5 0.0 27.2


Lake (%) 0.0 2.0 0.0 0.0 0.0 0.6 0.0 2.6

Infiltration Basin/Swale (%) 10.7 2.7 3.5 5.1 0.0 14.0 1.0 37.0

Soakwell (%) 0.0 0.5 0.1 0.2 0.0 1.3 0.0 2.1

Parks/Reserves (%) 5.9 0.0 0.0 0.2 0.0 2.0 0.0 8.2

Railway Reserve (%) 0.0 0.3 1.3 0.2 0.2 0.3 0.0 2.2

Total (%) 16.6 5.5 4.9 5.7 0.2 18.2 1.0 52.1

Total % of WESROC Area 35.0 7.8 6.2 6.8 11.0 31.5 1.7 100.0


J2868r.doc 2627 May, 2002

Table 13 :Drainage Discharge Areas by Land Use (% of Land Use Area)

Parks &Recreation

Passive

Parks &Recreation

Active

Residential<=R20zoning

Residential>R20

zoning

Commercial& Industrial

Total Area (sq km) 12.6 14.1 25.7 7.1 4.5


River Direct (%) 7.4 17.2 13.5 22.2 9.2

River via Comp Basin (%) 0.6 5.7 7.2 14.9 13.9

Total (%) 8.1 22.9 20.7 37.1 23.1


Ocean/Dunes Direct (%) 30.4 0.3 0.2 5.1 1.5

Ocean/Dunes via Comp Basin (%) 16.5 16.1 23.4 13.7 37.0

Total (%) 46.9 16.4 23.6 18.8 38.5


Lake (%) 1.4 5.3 1.6 4.4 0.4

Infiltration Basin/Swale (%) 22.6 37.1 44.9 36.5 34.1

Soakwell (%) 0.4 3.3 2.8 1.2 0.2

Parks/Reserves (%) 14.0 14.7 4.8 0.9 2.9

Railway Reserve (%) 6.7 0.3 1.6 1.1 0.8

Total (%) 45.1 60.7 55.7 44.1 38.4

Table 14 :Drainage Discharge Areas by Land Use (% of Total WESROC Area)

Parks &Recreation

Passive

Parks &Recreation

Active

Residential<=R20zoning

Residential>R20

zoning

Commercial& Industrial

Total

Total Area (sq km) 12.6 14.1 25.7 7.1 4.5 64.0


River Direct (%) 1.5 3.7 5.4 2.5 0.7 13.8

River via Comp Basin (%) 0.1 1.3 2.9 1.6 1.0 6.9

Total (%) 1.6 5.0 8.3 4.1 1.7 20.7


Ocean/Dunes Direct (%) 6.0 0.1 0.1 0.6 0.1 6.9

Ocean/Dunes via Comp Basin (%) 3.3 3.5 9.4 1.5 2.6 20.3

Total (%) 9.3 3.6 9.5 2.1 2.7 27.2


Lake (%) 0.2 1.2 0.6 0.5 0.0 2.5

Infiltration Basin/Swale (%) 4.5 8.2 18.0 4.1 2.4 37.2

Soakwell (%) 0.1 0.7 1.1 0.1 0.0 2.0

Parks/Reserves (%) 2.8 3.2 1.9 0.1 0.2 8.2

Railway Reserve (%) 1.3 0.1 0.7 0.1 0.0 2.2

Total (%) 8.9 13.4 22.3 4.9 2.7 52.1

Total % of WESROC Area 19.8 22.0 40.1 11.1 7.0 100.0


J2868r.doc 2727 May, 2002

6. IDENTIFYING PRIORITY SUB CATCHMENTS

6.1 Methodology

In the absence of detailed water quality data for the WESROC area, priority sub catchmentswere determined using map overlay techniques (Hollick, 1993) based on the following keyindicators of individual sub catchment stormwater quality :

estimated nutrient input (TP and TN) based on land use

the density of major roads (primary, secondary, and freeways)

the proportion of a total catchment which is commercial and industrial land use

historical land use considerations

These indicators were then analysed in relation to the nine discharge and receiving environmenttypes identified in Section 5.1 to determine priority sub catchments, with priority considerationgiven where drainage is to a Conservation Category Wetland.

These priorities do not include consideration of current local authority programs to improvestormwater quality in these sub catchments (eg street sweeping, gross pollutant traps). Existingprograms are discussed in relation to the priority catchments in Section 8.

6.2 Estimating Nutrient Input

6.2.1 Nutrient Input Decision Support System (NiDSS)

NiDSS is a tool developed by JDA Consultant Hydrologists to assist in landuse managementplanning, and allow quantitative estimation nutrient input rates and the potential reduction innutrient input (including costings) for various combinations of water sensitive urban design(WSUD) water quality management measures.

NiDSS focuses on the adoption of an integrated catchment approach to water qualitymanagement, including measures to minimise nutrient inputs at source, and provides a logicalframework for the evaluation of the effectiveness of various best management practices fornutrient input management.

It calculates the total expected nutrient input for a particular residential density based onaggregating individual nutrient inputs from different land uses (lots, POS, road reserves,conservation areas) prior to implementation of stormwater management measures. The impactof individual source and in-transit controls on nutrient input can then be determined by eitherturning on/off individual controls or varying the effectiveness of these measures. The resultspresent information on :

estimates of total phosphorus (TP) and total nitrogen (TN) application to an area

estimates of reductions due to source control measures (education, street sweeping)

estimates of reductions due to in-transit controls (Gross Pollutant Traps, WPCP’s)

estimates of the cost of removal (in PV terms) for a selected WSUD program.

Sample model input and output from NiDSS are shown in Appendix 3.


J2868r.doc 2827 May, 2002

6.2.2 Application to WESROC Area

NiDSS was applied to the Study Area to model existing land use and identify potential areas ofhigh nutrient input. Land use (Appendix 2) was accumulated into 5 main categories forassessment of nutrient input :

Residential : R20 zoning or less dense

Residential : greater density than R20 zoning

Commercial and Industrial

Parks and Recreation : Passive (eg Natural Bush)

Parks and Recreation : Active (eg Sports Fields, Golf Courses)

Nutrient application rates were adopted from the Southern River Urban Water ManagementStrategy (JDA, 2001), which based application rates on a nutrient input survey conducted byJDA of medium density residential areas, and on previous work of Gerritse et al (1991,1992 ).

Results are shown in Appendix 3 for individual local authorities, and summarised in Figure 24.These show high nutrient application areas to be typically residential areas of lower density(R20 or less dense). Areas include

Town of Cottesloe sub catchments adjacent to the railway line and Stirling Highway

City of Nedlands sub catchments south of Stirling Highway

City of Subiaco sub catchment draining to Lake Jualbup

the north eastern residential areas of the Town of Cambridge adjacent to Herdsman Lake

In interpreting the results of this analysis it should be noted that calculations have beenconducted and results collated to a sub catchment level, with a view to providing sufficient detailfor both local authority and regional priorities to be established. Assessment at a more detailedlevel within each sub catchment has not been performed as part of this study.

6.3 Qualitative Assessment of Other Pollutants

Indicators used to provide a qualitative assessment of other pollutants (including heavy metals)as presented in Section 6.1 are the density of major roads, proportion of industrial/commercialland, and the number of groundwater contamination sites.

The use of major road density as an indicator was based on JDA (1999), which found thatcompared to other diffuse sources of pollutants, road sediment is potentially a significant sourceof heavy metals (Cu, Pb, Zn) to receiving wetlands in Perth.

Mapping of major road densities and industrial/commercial land are shown in Figure 25 and 26respectively.

6.4 Local Authority Priority Catchments

Indicators for nutrient and other pollutant input were then analysed in relation to the ninedischarge and receiving environment types identified in Section 5.1 to determine priority subcatchments, with priority consideration given where discharge is to a Conservation CategoryWetland.

The top five priority subcatchments identified for each local authority are shown in Figure 27.


J2868r.doc 2927 May, 2002

In general terms, priority areas identified in this study correspond with areas previouslyidentified by individual local authorities to improve stormwater discharge quality, and some ofthe areas identified have already had stormwater quality improvement measures such as GPT’sinstalled. This correlation provides confidence in modelling and prioritising techniques applied inthis study.

A number of the priority subcatchments lie across local authority boundaries particularly thoselocated in Subiaco, Nedlands, Cambridge, and Cottesloe.

Detailed priority subcatchment calculations and complete priority listings are contained inAppendix 4.

6.5 WESROC Regional Priority Catchments

Priority subcatchments for WESROC on a regional basis are shown in Figure 28, whichpresents the regions top 20 priority areas.

The subcatchments identified as the top regional priority areas are primarily those along theeastern boundary of the Study Area, and those draining directly to conservation categorywetlands or the Swan River.

The local authorities with the highest density of regional priority areas are the Town ofCambridge, City of Subiaco, and the Town of Claremont. No regional priority catchments werelocated in either the Town of Cottesloe or Mosman Park.

Similarly to local authority priority areas (Figure 27), a number of the priority subcatchments lieacross local authority boundaries, particularly the City of Nedlands.


J2868r.doc 3027 May, 2002

7. STORMWATER QUALITY MANAGEMENT IN THECONTEXT OF WATER RESOURCES MANAGEMENT

7.1 Current Trends in Stormwater Management

Recent developments in urban stormwater quality management have seen a shift of emphasisfrom attempts to trap or retard pollutant in their journey from land application to estuarydischarge, to a more fundamental “Prevention is better than Cure” philosophy. This has seen amovement toward catchment management measures and pollutant input control rather than onpurely engineering approaches.

This proposed shift in emphasis from treatment to prevention, is taking place also in otherAustralian states. For example, in NSW the EPA requires each local authority to prepare aStormwater Management Plan, and to assist this process the EPA prepared a series of manualswhich focussed on source control methods. In practice however, virtually all plans preparedhave focussed on artificial wetlands to trap pollutants rather than on source controls to reduceinputs.

Locally, WRC’s A Manual for Managing Urban Stormwater Quality in Western Australia (1998)is currently under review and the revised document will provide a greater emphasis onstrengthening source controls and catchment management measures to reduce pollutant input,while still incorporating previously accepted water sensitive urban design measures and bestmanagement practice treatment trains.

7.2 Water Quality Management Options

Structural source controls are usually tested in laboratory situations by manufacturers and sometechnical information is available on the likely performance under various conditions. Thisinformation is used to predict performance in term of nutrient and pollutant retention ability, andtogether with associated capital and maintenance cost estimates, can be used to assess thelikely unit cost rate of removal.

It is more difficult to predict the effectiveness of non-structural source controls in water qualitymanagement. This is because non-structural measures cannot be readily tested by theconventional input/output methods, and for this reason, until recently there has traditionallybeen a reluctance to include non-structural source controls in stormwater managementprograms in other states. In particular in NSW, where the EPA has stressed a source controlphilosophy should be applied initially with in-transit controls only applied if necessary, a lack ofcost comparison between structural and non-structural source controls has been highlighted(NSW EPA, 1998).

Control of pollutants at source using non-structural measures, by minimisation or prevention ofinput, has the potential to be a very efficient water quality management option. Types of non-structural controls include :

Education Campaignswhich may include but are not limited to workshops for developers & residents, forming ofcommunity action groups, newspaper articles, distribution of leaflets, posters & newsletters,production and distribution of stickers & fridge magnets, drain stencilling or plaques,erection of informative signs in public areas, catchment model or exhibits at local events,shopping centres & schools, development of catchment walks, and performances written bycommunity members. Topics include but not limited to lawn and garden cutting disposal, carwashing detergent use and practices, pet waste disposal, bird feeding in POS areas,


J2868r.doc 3127 May, 2002

composting, drains to rivers, and fertilising habits. Examples of education campaignmaterial produced by the NSW EPA are presented in Appendix 5.

Refinement of Local Authority Management and Maintenance Activitiesincluding but not limited to education of council staff, regular review of council workpractices, refinement of street sweeping programmes and practices, minimising potential forsewer overflows, landscaping, and enforcement through infringement and pollution controlregulation.

Planting of Native Gardens at Development StagePOS areas, encouraging native plantings in residential lots. “Free” landscaping provided insome new house and land packages should promote use of local species.

Street Sweepingundertaking co-ordinated street cleaning programs to remove sediment build up

Land Use Planninginclusion of water quality considerations in planning decisions – land zonings, structure planlayouts, POS design and location.

Details of various structural control measures are provided in Tables 15 and 16, summarisingtheir suitability for various pollutants, constraints and relative capital and operating costs. Theselection of appropriate structural controls for individual situations will involve consideration of:

Types of pollutants to be removed Site constraints Lifecycle cost versus removal efficiency Public acceptance Equity issues (polluter pays principle) Ease of implementation

7.3 Cost Benefit Evaluation of Management Options

NiDSS was used to model the impact of implementing various WSUD measures within theStudy Area. Source control measures such as education and native gardens were found to beconsiderably more effective in reducing nutrient input than in-transit structural measures used totrap and remove inputs.

JDA (2000) estimated in the order of 5% of nutrient application is exported with stormwaterrunoff, with the remainder of nutrients stored in the soil profile or entering the shallowgroundwater system. Therefore even efficient in-transit measures are found to typically trap onlyvery small amounts (<5%) of nutrient application to a catchment.

Source controls are therefore considered the only method by which significant reduction innutrient application to a catchment can be achieved.

NiDSS modelling results are summarised in Figure 29 with modelling detail contained inAppendix 5. Order of cost for reducing phosphorus inputs were found to be free for nativeplantings (assuming planting to be undertaken using exotic species anyway), <$5/kg/yr foreducation programs, $150/kg/yr for street sweeping, $800/kg/yr for GPTs, and $4000/kg/yr forWater Pollution Control Ponds.

Figure 30 demonstrates the potential impact for various degrees of success of educationcampaigns on reducing nutrient application rates for the WESROC area.

With respect to other pollutants besides nutrients there is very little data available on costs oftreatment.


J2868r.doc 3227 May, 2002

Table 15 : Pollutant Removal Efficiencies For Various Structural ControlsPollutant Removal Efficiency

neg : Negligible [0-10% removal]M :Moderate [50-75% removal]

L : Low [10-50% removal]H : High [75-100% removal]

Treatment Measure

Litt

er

an

d g

ross

po

lluta

nts

(>

50

0 µ

m)

Co

ars

e s

ed

ime

nt

(>2

00

µm

)

Fin

e s

ed

ime

nt

& s

usp

en

de

d s

olid

s(<

20

0 µ

m)

To

tal p

ho

sph

oru

s

Dis

solv

ed

ph

osp

ho

rus

To

tal n

itro

ge

n

Dis

solv

ed

nitr

og

en

Oil

an

d g

rea

se

Oxy

ge

n d

em

an

din

g s

ub

sta

nce

s (B

OD

)

Po

ten

tial f

or

po

lluta

nt

re-m

ob

ilisa

tion

Litter baskets/ pits/ bags H L neg neg neg neg neg neg L L

Litter / trash racks M L neg neg neg neg neg neg L M

Sediment Traps L H M L neg L neg L L M

Gross Pollutant Traps H H M L neg L neg L L M

Oil and grit traps M M L L neg L neg H L H

Sand filters L M M M neg M neg M M L

Filter strips neg H M L neg L neg L L L

Bioretention systems L L H H L H L M L L

Soil Amendment neg M M H M M L M M M

Grass swales L H M L neg L neg L L L

Infiltration trenches L H M M neg M neg L M L

Pool and riffles L H M L L L L L L H

Infiltration basins L H H M neg L neg L M L

Detention basins L H M M neg L neg neg L M

Amended Soil PondTreatment Systems L H H M M L L L L L

Constructed wetlands /Water Pollution ControlPonds (WPCP’s)

L H M M L L L M L M

Adapted from: EPA (1993) (as adapted from Schueler (1987), Horner et al. (1994) & Mudgeway et al. (1997)), WRC(1998), Lawrence & Breen (1998), US EPA (1999) and Ecomax (undated). Efficiencies quoted for pollutant removalshould be considered indicative only.


J2868r.doc 3327 May, 2002

Table 16 : Potential Constraints For Various Structural ControlsPotential Constraint

: Constraint may preclude use

• : Constraint may be overcome with appropriate design

: Generally not a constraint

IndicativeRelative Cost

H : HighM : Medium

L : Low

Treatment MeasureS

tee

p s

ite/c

atc

hm

en

t sl

op

e

Hig

h w

ate

r ta

ble

Lim

ited

lan

d a

vaila

bili

ty

Po

llute

d g

rou

nd

wa

ter

Co

vere

d t

rea

tme

nt

me

asu

re is

required

Hig

h s

ed

ime

nt

inp

ut

Tre

atm

en

t m

ea

sure

re

qu

ire

spre

-tre

atm

ent

Hyd

rau

lic h

ea

d lo

ss li

mita

tion

On

go

ing

op

era

tion

/ m

ain

ten

an

ceco

sts

Ca

pita

l co

st

Litter baskets/ pits/ bags • • H L

Litter / trash racks • • H L

Sediment Traps • • • • M M

Gross Pollutant Traps • • • • H M

Oil and grit traps H M

Sand filters • M M

Filter strips L L

Grass swales L L

Bioretention systems M M

Soil Amendment • • • • • L M

Infiltration trenches • • M M

Pool and riffles • • • M L

Infiltration basins • • M M

Detention basins • • • • L M

Amended Soil PondTreatment Systems • • • L M

Constructed wetlands /Water Pollution ControlPonds

• • • M H

Adapted from: EPA (1993) (as adapted from Schueler (1987) and Horner et al. (1994)), WRC (1998), US EPA (1999)and Ecomax (undated).


J2868r.doc 3427 May, 2002

7.4 Water Resources Perspective

The co-operation of the Western Suburbs local authorities in the framework of WESROC for thisstudy, opens the option of exploring opportunities for treating stormwater as a resource ratherthan as a nuisance to be disposed of. Particularly under the drier climate experienced in thesouth-west of WA since about 1975, the option of reused of stormwater is being increasinglydebated.

The opportunities for stormwater reuse, particularly for irrigation, would appear to be greatestwhere stormwater is discharged to either the Swan River or the ocean. Discharge to theselocations inevitably leads to an increase in the salinity of the discharge water and prevents itsreuse for irrigation.

On the other hand, where stormwater is infiltrated inland, as in wetlands or lakes it effectivelybecomes a reusable resource and adds to the shallow groundwater aquifer.

It follows that options for stormwater reuse should be focussed on those catchments which havebeen identified in this report as discharging to the Swan River or Indian Ocean. Investigation ofthe options inevitably involves consideration of natural topographic catchments, rather than localauthority boundaries.

Notable examples are :

the export of much of the City of Subiaco stormwater through a Water Corporation MainDrainage System to the Indian Ocean, routed through the City of Nedlands, Town ofCambridge, and then City of Nedlands at its outlet (Figure 23).

the export of stormwater on the boundary between City of Subiaco and Town of Cambridge,including north-east corner of the City of Nedlands, via Lake Monger to the Swan River(Figure 23).

the southern boundary of City of Subiaco, City of Nedlands, Town of Claremont and theeastern boundary of Town of Mosman Park and Shire of Peppermint Grove, which drainsdirectly to the river, although these outlets do not cross local government boundaries.

Approximately 27.4 % of the WESROC area does discharge via a piped system to the IndianOcean (and the surrounding dunes), and 20.7 % by piped system to the Swan River. It is theseareas where reuse of stormwater in the context of it being a resource, could be focussed.


J2868r.doc 3527 May, 2002

8. PROPOSED STRATEGY

The following Chapter details key elements of the proposed regional strategy for stormwaterquality on the basis of the analysis and data presented in previous chapters of this report.

Details regarding specific implementation plans for individual local authorities to comply with thisstrategy and undertake works to target key priority areas identified in Figures 27 and 28 arepresented in Section 9.

8.1 Objectives and Criteria

Together with the Swan River Trust, Water & Rivers Commission and the Department ofEnvironmental Protection, WESROC identified the need for better management of stormwaterquality and the need to address the associated strategic issues on a broad catchment basis.

On this basis, the main objective of the strategy is defined as to bring together issuesconcerning the collection and disposal of stormwater in WESROC with the aim of managing thequality of stormwater discharging into the Swan River, Indian Ocean, local wetlands, and thegroundwater system, and to provide a framework for a co-ordinated approach to improvingstormwater quality.

Given the current lack of a clear set of criteria or objectives set at the State Government level,local authorities and groupings such as WESROC have a degree of flexibility in the type ofstrategy to be developed and implemented. To this end, it is considered that the strategy viewstormwater quality management within the context of the broader management of waterresources on the Swan Coastal Plain.

This strategy therefore presents a holistic water resources management approach with abroader focus to include water resources aspects rather than purely the treatment of stormwaterquality to a certain, undefined, standard.

8.2 The Strategy

Recent developments in urban stormwater quality management have seen a shift of emphasisfrom attempts to trap or retard pollutants in their journey from land application to estuarydischarge, to a more fundamental “Prevention is better than Cure” philosophy. WRC’s A Manualfor Managing Urban Stormwater Quality in Western Australia (1998) is currently under reviewand the revised document will provide a greater emphasis on strengthening source controls andcatchment management measures to reduce pollutant input, while still incorporating previouslyaccepted water sensitive urban design (WSUD) measures and best management practicetreatment trains.

The strategy recommended for WESROC follows this approach and considers source controltechniques to be vital to achieving stormwater quality improvements. The proposed strategy ismindful of the financial costs to local authorities and communities of stormwater qualitymanagement and has been developed accordingly.

To this end the strategy recommends the use of education campaigns, native plantings, andstreet sweeping as preferred comparatively low cost methods of reducing nutrients andpollutants and protecting receiving environments. Many local authorities already undertake co-ordinated street sweeping programs, and in many instances previous lake management andenvironmental plans have highlighted the need for public education as a major influence ofstormwater quality. Where possible, integration with existing programs is recommended.


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In terms of Gross Pollutant Traps (GPT’s), these will still be required in certain instances as partof applying a treatment train approach. The need for GPT’s will require assessment on a caseby case basis. Given the number of discharge locations, and the significant cost of installationand maintenance of these units it is recommended some monitoring of stormwater quality beundertaken prior to installation to first determine whether a GPT is required at all, and secondlythe most suitable to install to meet the water quality requirements of the receiving environment.Preliminary analysis of stormwater monitoring being undertaken by JDA on behalf of the Townof Mosman Park indicate a large proportion of dry material travelling through the stormwatersystem is trapped by standard council gullies, and hence less costly GPT’s may be equally asapplicable as more sophisticated units in some applications.

Given WESROC’s established nature and their high land requirement, and capital andmaintenance costs, the use of Water Pollution Control Ponds (WPCP) is not considered a viablealternative and are not recommended.

The strategy has identified priority catchments at both a local authority and regional scale, and itis recommended these priorities be used as a basis for ongoing works on stormwater qualitywithin the region. A number of priority catchments drain to Water Corporation Main Drainage.Negotiation with Water Corporation regarding any works for these catchments will be requiredon a case by case basis.


In terms of water resources management, discharge of stormwater to the Indian Ocean andSwan River via Water Corporation main drainage represents a major discharge from theWESROC area. These discharges primarily come from the 3 larger local authority areas ofSubiaco, Nedlands and Cambridge. There is therefore an argument for these three localauthorities to perhaps target these discharges from a potential water resource and re-useperspective.

8.3 Monitoring

It is recommended WESROC undertake an integrated monitoring program targeting keycatchments to establish baseline stormwater quality data from which future water quality criteriacan be established.

Stormwater inflow sites to be included in the monitoring program should be based on theidentified regional priority catchments, focussing on major discharges to the Indian Ocean andSwan River.

A typical monitoring program would consist of monthly water quality monitoring over a 5 to 6month winter period (including first flush in April/May) Samples would be obtained by manualgrab sampling during storm events, at several key locations within each identified prioritycatchment. Samples would require laboratory analysis, typically for the following parameters :

pH, Conductivity, Total Dissolved Solids (TDS)

Total Phosphorus and Filterable Reactive Phosphorus (FRP)

Total Nitrogen (TN), Total Kjeldahl Nitrogen (TKN), NO3, NO2, Ammonia

Heavy Metals (including Pb, Zn, Cu)

Hydrocarbons

Analysis of the monitoring program results would need to be undertaken to interpret data in thecontext of the Regional Strategy and to develop recommendations for any further actionaccordingly.


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Depending on the priority catchment being monitored and its receiving environment, themonitoring of herbicides/pesticides should also be considered. This data would assist localauthorities in assessing the impacts of POS and kerbside weed spraying programs onstormwater quality.

8.4 Review

Annual review of the implementation programs is recommended. With regard to the Strategydocument itself, it is recommended the Strategy be reviewed after a period of 4 years. Thisreview process would include :

assessment of the success of measure implemented and programs undertaken.

analysis of monitoring data collected over this period to provide the baseline data to definespecific water quality criteria.





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9. IMPLEMENTATION PLANS

Implementation plans for the strategy at a regional level and for individual local authorities arepresented in Tables 17 to 24.

Implementation plans for individual authorities have been based on the top few prioritycatchments within each local authority with an emphasis on regional priority subcatchments.The status the existing programs and monitoring for each subcatchment is discussed withrecommendations as to proposed actions if required. In many cases, priority catchment havealready been targeted by the relevant local authorities and studies and/or infrastructureimplemented.

General recommendations regarding the implementation of education campaigns and their keytarget areas are also provided for each local authority.

These plans should be considered indicative only and subject to review by individual localauthorities.


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Table 17 : WESROC Implementation Plan

Role and Proposed Actions

Consider opportunities for drainage currently discharged to Indian Ocean and Swan River for potentialuse as water resource

Encourage infiltration of new development, where practicable

Development and implementation of an integrated monitoring program targeting key catchments toestablish baseline stormwater quality data from which future water quality criteria can be established.

Facilitate annual review of implementation programs and assessment of priorities. Assessment / co-ordination of local authority implementation plans within the context of regional priority considerationsand cross local authority boundary issues.

Facilitate review of stormwater quality strategy after 4 years :

assess success of measures implemented and programs undertaken.

analysis of monitoring data collected to provide baseline data to define water quality criteria.




Table 18 : Town of Claremont Implementation Plan

Priority Subcatchment Existing Status and Proposed Action

GeneralDevelopment and implementation of education programs for residents of regional priority catchments

Review existing street sweeping operations with stormwater management considerations

CL 21Regional Priority Catchment (1-5)

128 ha catchment including main Claremont town centre and StirlingHighway runoff. Minor contributions from Town of Cottesloe and Cityof Nedlands. Drainage directly to Swan River via Water CorporationMain Drain, with recent drainage upgrade undertaken. No GPT.Anecdotal evidence of visible pollution plume in river duringstormwater inflow events. Regular street sweeping of commercialareas and less frequent sweeping of residential areas undertaken.

Recommended Action : Develop and undertake stormwatermonitoring program, review adequacy of existing street sweepingoperations, investigate opportunities for installation of GPT,negotiations with Water Corporation.

CL 2Regional Priority Catchment (5-10)

163 ha catchment of Lake Claremont, a conservation categorywetland. Catchment predominantly residential and active recreation(golf course). Part of catchment is located within the City of Nedlands.Many previous report of lake water quality and proposed managementplans. Previous studies recommend catchment management approachto water quality largely through education and monitoring.

Recommended Action : Development and implementation ofstormwater discharge quality monitoring program, and communityeducation programs. Review of golf course fertiliser applicationprograms. Improvement of lake foreshore and riparian zones.


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Table 19 : Town of Cambridge Implementation Plan

Priority Subcatchment Existing Status Proposed Action


Review existing street sweeping operations with stormwater management considerations, particularly forareas draining to Conservation Category Wetlands (Perry Lakes, Lake Monger, and Herdsman Lake).

Investigate general opportunities for increased infiltration and reduced export of stormwater.

ST 3Regional Priority Catchment (1-5)

191 ha catchment largely R10 to R20 residential which drains acrossthe northern local authority boundary into Herdsman Lake (aconservation category wetland) in the City of Stirling.

Recommended Action : Develop and undertake stormwatermonitoring program, investigate opportunities for installation of GPT

CA 37Regional Priority Catchment (6-10)

63 ha catchment draining into the City of Perth and the Swan River viaWater Corporation Main Drainage. Catchment predominantlyresidential with substantial amount of commercial and industrial land.

Recommended Action : Develop and undertake stormwatermonitoring program, investigate opportunities for installation of GPT ascatchment has a high density of major roads

CA 28Regional Priority Catchment (6-10)

Large 429 ha catchment of Perry Lakes, a conservation categorywetland. Land Use mainly parks and recreation with 26% residentialdevelopment (R10-R20). The southern part of the catchment lieswithin City of Nedlands. Previous report of lake water quality andproposed management plan. Water quality within the lakes is generallyconsidered acceptable. Previous studies recommend water quality andlake level monitoring.

Recommended Action : Development and implementation ofstormwater discharge quality monitoring program, and communityeducation programs for local residents in the catchment, investigateopportunities for installation of GPT


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Table 20 : Town of Cottesloe Implementation Plan

Priority Subcatchment Existing Status Proposed Action

General

Only 1 catchment in the Town of Cottesloe is classified as a Regional Priority subcatchments.

Approximately 71% of the total local authority area is infiltrated either in railway reserves or infiltrationbasins/swales. Similarly to the Town of Mosman Park, this provides for use of stormwater as a resourcein an area where groundwater is scarce.

Review existing street sweeping operations with stormwater management considerations with anemphasis on coastal ocean/dune discharge catchments.

CO 44Regional Priority Catchment (20-25)

10 ha catchment of predominantly R25-R60 residential zoning withsome commercial zoning discharging to the Indian Ocean. Althoughthe highest priority catchment for Cottesloe it is only ranked outsidethe top 20 catchments from a regional perspective. The Town ofCottesloe has previously installed some GPT’s on nearby catchmentoutlets under a Clean Seas program grant and is undertaking amonitoring program of their efficiencies.

Recommended Action : Continue existing monitoring program ofother GPT’s. Await outcomes of monitoring program of catchmentCO 7 and CO 20. Possible installation of GPT on catchment outlet.

CO 40 16 ha catchment of predominantly R25-R60 residential zoning withsome commercial zoning discharging to the Indian Ocean.Catchment land use largely similar to CO 44, and lies immediatelyadjacent to this catchment.

Recommended Action : Await outcomes of monitoring program ofcatchment CO 44. Possible installation of GPT on catchment outlet.

Table 21 : Town of Mosman Park Implementation Plan


General

No catchments within the Town of Mosman Park are classified as Regional Priority subcatchments.

Approxiamtely 83% of the total local authority area is infiltrated, which provides the opportunity for use ofstormwater as a water resource in an area where groundwater is scarce.

Review existing street sweeping operations with stormwater management considerations with anemphasis on river discharge catchments.

MP 13 6 ha catchment of predominately R10-R20 zoning directlydischarging to the Swan River. Although the highest prioritycatchment for Mosman Park it is not ranked within the top 25catchments from a regional perspective. The Town of Mosman Parkhas previously installed a GPT on catchment MP3’s outlet under aClean Seas program grant and is undertaking a monitoring programof its efficiency.

Recommended Action : Continue existing monitoring program.Continue existing monitoring program of GPT for catchment MP3.Await outcomes of monitoring program. Possible installation of GPTon catchment outlet.


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Table 22 : City of Subiaco Implementation Plan



Review existing street sweeping operations with stormwater management considerations, particularly forcatchment areas draining to Conservation Category Wetlands (Mabel Talbot) and directly to the IndianOcean and Swan River.


SU 1Regional Priority Catchment (1-5)

244 ha catchment largely R10 to R20 residential with somecommercial and relatively high density of major roads. Drains to MabelTalbot Lake (Conservation Category Wetland) and then via WaterCorporation Main Drainage to the Swan River. The majority of hiscatchment lies within the Town of Cambridge.

Recommended Action : Develop and undertake stormwatermonitoring program, investigate opportunities for installation of GPT,Undertake community education programs for local residents in thecatchment


50 ha catchment draining to the Swan River via Lake Monger(Conservation Category Wetland). Includes Subi Centro. Catchmenthas a high percentage of commercial area (>50%). High density livingand commercial land indicates nutrient levels in stormwater likely to berelatively low. Education campaign of residents regarding nutrientinputs may not be applicable here.

Recommended Action : Develop and undertake stormwatermonitoring program, investigate opportunities for installation of GPTbased on monitoring outcomes..


Large 242 ha catchment includes Hay St /Rokeby Rd shoppingprecinct. Comparatively high density of major roads. Discharges toCliff Sadlier Park before discharging to the Indian Ocean via WaterCorporation Main Drainage.

Recommended Action : Investigate general opportunities forincreased infiltration and reduced export of stormwater.Community education program for local residents


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Table 23 : City of Nedlands Implementation Plan


GeneralDevelopment and implementation of education programs for residents particularly in areas draining tothe Swan River and residential areas zoned R10-R20.

Review existing street sweeping operations with stormwater management considerations.


NE 30Regional Priority Catchment (11-15)

140 ha catchment including Sir Charles Gairdener Hospital complex.Drains to Lake Jualbup in the City of Subiaco which is aconservation category wetland prior to discharge to the IndianOcean via Water Corporation Main Drain. Catchment includes areaswithin the City of Subiaco including Rosalie Park. City of Subiacorecently undertaken improvement works at Lake Jualbup to removeconcrete edging and to install GPT’s on some outlets.

Recommended Action : In conjunction with the City of Subiacodevelop and undertake stormwater monitoring program, andconsider installation of GPT depending on monitoring programoutcomes.

NE 53Regional Priority Catchment (11-15)

52 ha catchment predominately residential and active recreationwith drainage to the Swan River near the Nedlands Hotel. GPT’salready previously installed by the City of Nedlands on river outlets.

Recommended Action : No action.NE 51Regional Priority Catchment (16-20)

32 ha catchment predominately residential and active recreationwith drainage direct to the Swan River.

Recommended Action : Develop and undertake stormwatermonitoring program, investigate opportunities for installation of GPTbased on monitoring outcomes.

Table 24 : Shire of Peppermint Grove Implementation Plan


General

No general actions proposed.

PG 2Regional Priority Catchment (20-25)

44 ha catchment of R10-R20 zoning with some active recreationareas. Contains a large number (10) of river outlets. Although thehighest priority catchment for Peppermint Grove, the catchment stillrepresents a relatively low priority from a regional perspective.

Recommended Action : Develop and undertake stormwatermonitoring program of a key identified outlet. Develop andimplement education programs for residents, and review existingstreet sweeping operations with stormwater managementconsiderations


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10. CONCLUSIONS/RECOMMENDATIONS

General

WESROC comprises the local government authorities of Claremont, Cottesloe, MosmanPark, Nedlands, Subiaco, and Peppermint Grove. The Town of Cambridge while not aformal member of WESROC is also a contributing participant for this study.

The Study Area is generally bounded by the Indian Ocean to the west, Kings Park and theMitchell Freeway to the east, Herdsman Lake to the north and the Swan River to the south.

The total Study Area is approximately 64.4 km2, with the Town of Cambridge and the City ofNedlands comprising over 65% of the total Study Area.

The topography is generally undulating, typically varying between 0 to 30 mAHD over mostof the Study Area, with some elevated areas in the Town of Cambridge’s Bold Park whichare in excess of 80 mAHD.

The Study Area has a Mediterranean climate with mild wet winters and hot dry summers,and has a long term average annual rainfall of approximately 860mm.

The majority of land in the Study Area is urban with some pockets of commercial andindustrial land associated particularly with town centres. Some large areas of public openspace are located at Perry Lakes and Bold Park in the Town of Cambridge. Most urbanareas are well established, though there are some new development areas, including newsubdivisions at Mount Claremont (City of Nedlands), Subi Centro (City of Subiaco) andMinim Cove (Town of Mosman Park).

Surface and Groundwater Hydrology

Surface drainage within the Study Area varies widely, comprising of a network of piped localdrainage and Water Corporation Main Drainage, which feeds to a variety of receiving bodiesincluding the Swan River, Indian Ocean, Lakes (Monger, Herdsman, Jualbup, Claremont,Mabel Talbot, Perry Lakes), Compensating Basins, Infiltration Basins, Swales, andSoakwells.

Maximum recorded groundwater levels vary from 1 mAHD near the coast and Swan Riverto 14 mAHD on the north east boundary at Lake Monger. Seasonal groundwater variationon the Swan Coastal Pain is typically in the order of 1.0 to 1.5 m.

Much of the Study Area has considerable depth to groundwater and hence provides anopportunity for infiltration of surface drainage.

Conservation Category Wetlands (CCW’s) within the Study Area (Figure 6) are Perry Lakes(Town of Cambridge), Lake Monger (Town of Cambridge), Mabel Talbot (City of Subiaco),Lake Claremont (Town of Claremont), and Pelican Point (City of Subiaco). No CCW’s arelocated within the Towns of Cottesloe and Mosman Park, the Shire of Peppermint Groveand the City of Nedlands.

All CCW’s apart from Pelican Point are part of the formal drainage network, and all lakes,with the exception of Lake Claremont, are part of the Water Corporation’s Main DrainageSystem.

Other non conservation category wetlands within the Study Area include Lake Jualbup andthe QE2 Medical Centre Lake.


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Water Quality Data

The majority of previous studies undertaken in the Study Area related to stormwater arequantity rather than quality related studies, with the exception of Perry Lakes and LakeMonger which have had a number of environmental studies undertaken, and both havecurrent environmental management plans.

Most previous water quality monitoring studies undertaken by the Town of Mosman Parkand Town of Cottesloe were undertaken to monitor irrigation bore salinities.

Overall, little data exists regarding stormwater quality within the Study Area. Mostmonitoring has focused on sampling of the receiving environment water quality (PerryLakes, Lake Monger etc) rather than the quality of stormwater inflows.

Water Quality Standards & Criteria

Currently applicable standards and criteria for stormwater quality are ill-defined at the StateGovernment level in Western Australia. WRC are currently in the process of reviewing itsapproach to urban stormwater management and it is expected that the outcomes of thisprocess will provide a clearer definition of water quality standards and criteria to apply inurban stormwater management.

WRC have recently commenced a major review of the Manual for Managing UrbanStormwater Quality in Western Australia (1998). The focus of the review is to incorporateBMP information on new products, and to critically review the approach of attempting totreat large volumes of water from infrequent high rainfall events. Until the Manual isupdated, WRC has encouraged the use of “source control” and “in-transit” control as theprimary approach for stormwater quality management.

The determination of water quality standards and criteria for an established area such asthat covered by WESROC is not straightforward, particularly as no well establishedguidelines currently exist at the State Government level.

The approach recommended for the establishment of criteria for water quality managementfor WESROC is based on first determining existing storm water quality in the area throughthe development and implementation of monitoring programs and then to use this data toestablish suitable water quality targets.

The establishment of targets without first determining existing storm water quality is notrecommended as this may lead to a perceived failure to meet targets that may not beachievable, and may also lead to the implementation of inappropriate pollution controlmeasures at cost to local community.

Development of Regional Drainage Plans

Regional drainage plans were developed for each local authority, providing detail of subcatchment boundaries, the interaction of drainage flows across local authority boundaries,the location of key drainage facilities, (including infiltration basins, compensating basins,gross pollutant traps), Water Corporation Main Drainage, and the location of key outlets tothe Swan River and Indian Ocean.

Individual local authority drainage plans were collated to prepare a drainage overview mapfor the whole of the WESROC area, and summary statistics were developed for variousdischarge types (Swan River, Indian Ocean, and Groundwater) at individual local authoritylevel and for various land use types.

45% of the total WESROC area lies in catchments which cross local authority boundaries


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52.1% of the WESROC area was found to infiltrate stormwater, 20.7% to discharge to theSwan River, and 27.2% to discharge the Indian Ocean (and the surrounding dunes), largelyvia Water Corporation Main Drainage.

With respect to individual local authority areas results show there is considerabledifferences between individual local authorities drainage systems. The Town of MosmanPark has the highest proportion of area infiltrated at 82.6% ranging to the City of Subiacowhich infiltrates less than 2% of its total area. Conversely, 67.6% of the total City of Subiacoarea is exported to the Indian Ocean via Water Corporation Main Drainage while the Townof Claremont has none. The City of Subiaco has the largest percentage of area whichdischarges to the Swan River at 30.6%.

The results highlight the need for management at both regional and local scales, particularlygiven the large variation in the size of local authorities. The results also highlight theimportance of the two large authorities (City of Nedlands, Town of Cambridge) towardachieving regional outcomes.

Priority Sub Catchments

In the absence of detailed water quality data for the WESROC area, priority sub catchmentswere determined using map overlay techniques (Hollick, 1993) based on the following keyindicators of individual sub catchment stormwater quality : estimated nutrient input (TP andTN) based on land use, the density of major roads (primary, secondary, and freeways), theproportion of a total catchment which is commercial and industrial land use, and historicalland use considerations.

Indicators were analysed in relation to various discharge and receiving environment types todetermine priority sub catchments, with priority consideration given where drainage is to aConservation Category Wetland.

Areas identified as likely to have high nutrient application were Town of Cottesloe subcatchments adjacent to the railway line and Stirling Highway, City of Nedlands subcatchments south of Stirling Highway, City of Subiaco areas draining to Lake Jualbup, thenorth eastern residential areas of the Town of Cambridge adjacent to Herdsman Lake

The top five priority subcatchments were identified for each local authority. In general terms,priority areas identified in this study correspond with areas previously identified by individuallocal authorities to improve stormwater discharge quality, and some of the areas identifiedhave already had stormwater quality improvement measures such as GPT’s installed. Thiscorrelation provides confidence in modelling and prioritising techniques applied in this study.

A number of the priority subcatchments lie across local authority boundaries particularlythose located in Subiaco, Nedlands, Cambridge, and Cottesloe.

The top 20 priority subcatchments for WESROC on a regional basis were also identified.The subcatchments identified as the top regional priority areas are primarily those along theeastern boundary of the Study Area, and those draining directly to conservation categorywetlands or the Swan River.

The local authorities with the highest density of regional priority areas are the Town ofCambridge, City of Subiaco, and the Town of Claremont. No regional priority catchmentswere located in either the Town of Cottesloe or Mosman Park.

Trends in Stormwater Management

Recent developments in urban stormwater quality management have seen a shift ofemphasis from attempts to trap or retard pollutant in their journey from land application toestuary discharge, to a more fundamental “Prevention is better than Cure” philosophy. This


J2868r.doc 4727 May, 2002

has seen a movement toward catchment management measures and pollutant input controlrather than on purely engineering approaches.

Locally, WRC’s A Manual for Managing Urban Stormwater Quality in Western Australia(1998) is currently under review and the revised document will provide a greater emphasison strengthening source controls and catchment management measures to reduce pollutantinput, while still incorporating previously accepted water sensitive urban design measuresand best management practice treatment trains.

Cost Benefit Evaluation of Management Options

NiDSS was used to model the impact of implementing various WSUD measures within theStudy Area. Source control measures such as education and native gardens were found tobe considerably more effective in reducing nutrient input than in-transit structural measuresused to trap and remove inputs.

It is estimated that in the order of 5% of nutrient application is exported with stormwaterrunoff, with the remainder of nutrients stored in the soil profile or entering the shallowgroundwater system. Therefore even efficient in-transit measures are found to typically traponly very small amounts (<5%) of nutrient application to a catchment. Source controls aretherefore considered the only method by which significant reduction in nutrient application toa catchment can be achieved.

Order of cost for reducing phosphorus inputs were found to be free for native plantings(assuming planting to be undertaken using exotic species anyway), <$5/kg/yr for educationprograms, $150/kg/yr for street sweeping, $800/kg/yr for GPTs, and $4000/kg/yr for WaterPollution Control Ponds.

With respect to other pollutants besides nutrients there is very little data available on costsof treatment.

Water Resources Perspective

The co-operation of the Western Suburbs local authorities in the framework of WESROC forthis study, opens the option of exploring opportunities for treating stormwater as a resourcerather than as a nuisance to be disposed of. Particularly under the drier climate experiencedin the south-west of WA since about 1975, the option of reused of stormwater is beingincreasingly debated.

The opportunities for stormwater reuse, particularly for irrigation, would appear to begreatest where stormwater is discharged to either the Swan River or the ocean. Wherestormwater is infiltrated inland, as in wetlands or lakes it effectively becomes a reusableresource and adds to the shallow groundwater aquifer.

Approximately 27.2 % of the WESROC area does discharge via a piped system to theIndian Ocean, and 20.7 % by piped system to the Swan River. It is these areas where reuseof stormwater in the context of it being a resource, should be focussed.

The Strategy

It is recommended that the strategy view stormwater quality management within the contextof the broader management of water resources on the Swan Coastal Plain. The strategytherefore presents a holistic water resources management approach with a broader focus toinclude water resources aspects rather than purely the treatment of stormwater quality to acertain, undefined, standard.

The strategy recommended for WESROC considers monitoring and source controltechniques to be vital to achieving stormwater quality improvements. The proposed strategy


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is mindful of the financial costs to local authorities and communities of stormwater qualitymanagement and has been developed accordingly.

The strategy recommends the use of education campaigns, native plantings, and streetsweeping as preferred comparatively low cost methods of reducing nutrients and pollutantsand protecting receiving environments. Many local authorities already undertake co-ordinated street sweeping programs, and in many instances previous lake management andenvironmental plans have highlighted the need for public education as a major influence ofstormwater quality. Where possible, integration with existing programs is recommended.

In terms of Gross Pollutant Traps (GPT’s), these will still be required in certain instances aspart of applying a treatment train approach. The need for GPT’s will require assessment ona case by case basis. Given the number of discharge locations, and the significant cost ofinstallation and maintenance of these units it is recommended some monitoring ofstormwater quality be undertaken prior to installation to first determine whether a GPT isrequired at all, and secondly the most suitable to install to meet the water qualityrequirements of the receiving environment.

Given WESROC’s established nature and their high land requirement, and capital andmaintenance costs, the use of Water Pollution Control Ponds (WPCP) is not considered aviable alternative and are not recommended.

The strategy has identified priority catchments at both a local authority and regional scale,and it is recommended these priorities be used as a basis for ongoing works on stormwaterquality within the region. A number of priority catchments drain to Water Corporation MainDrainage. Negotiation with Water Corporation regarding any works for these catchments willbe required on a case by case basis.


In terms of water resources management, discharge of stormwater to the Indian Ocean andSwan River via Water Corporation main drainage represents a major discharge from theWESROC area. These discharges primarily come from the 3 larger local authority areas ofSubiaco, Nedlands and Cambridge. It is recommended these local authorities consideropportunities to target these discharges from a potential water resource and re-useperspective.

Monitoring and Review

It is recommended WESROC undertake an integrated monitoring program targeting keycatchments to establish baseline stormwater quality data from which future water qualitycriteria can be established. Stormwater inflow sites to be included in the monitoring programshould be based on the identified regional priority catchments, focussing on majordischarges to the Indian Ocean and Swan River.

Annual review of implementation programs is recommended.

With regard to the Strategy document itself, it is recommended the Strategy be reviewedafter a period of 4 years. This review process would include an assessment of the successof measure implemented and programs undertaken, analysis of monitoring data collectedover this period to provide the baseline data to define specific water quality criteria,integration of criteria and policy developments at the State Government level, and a reviewof new developments in stormwater quality management.


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Implementation Plans

Implementation plans for the strategy at a regional level and for individual local authoritieshave been developed. Implementation plans for individual authorities have been developedbased on the top few priority catchments within each local authority with an emphasis onregional priority subcatchments. The plans present the status of existing programs andmonitoring for each subcatchment with recommendations as to proposed actions if required.In many cases, priority catchments have already been targeted by the relevant localauthorities and studies and/or infrastructure implemented, and in these casesrecommendations build on existing programs.


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11. REFERENCES

Australian and New Zealand Environment and Conservation Council and Agriculture andResource Management Council of Australia and New Zealand (2000a), Australian and NewZealand Guidelines for Fresh and Marine Water Quality, National Water Quality ManagementStrategy, October 2000

Australian and New Zealand Environment and Conservation Council and Agriculture andResource Management Council of Australia and New Zealand (2000b), Australian Guidelinesfor Water Quality Monitoring and Reporting, National Water Quality Management Strategy,October 2000

Australian and New Zealand Environment and Conservation Council and Agriculture andResource Management Council of Australia and New Zealand (2000c), Australian Guidelines forUrban Stormwater Management, National Water Quality Management Strategy, 2000

Bunny, B.J. and Ruiz-Avila R.J (1995) Lake Claremont Catchment Land Information Study,December 1995, Prepared for the Lake Claremont Management Committee and the Town ofClaremont

City of Perth (1992), Lake Monger Management Plan 1993-1998, Part 1 (Background) and Part2 (Plan for Management), November 1992

City of Subiaco, Environmental Plan (undated)

Dames & Moore (1992), Perry Lakes Environmental Management Study, April 1992

David Porter Consulting Engineer (2000), Review of Drainage Issues – Robert St Dalkeith,Leura St Nedlands, Mason Gardens Nedlands & Drainage Sumps in Napier St and Loftus StNedlands. September 2000

Environmental Protection Authority (1997), Environmental Protection (Swan and CanningRivers) Policy 1997

Environmental Protection Authority Bulletin (1993), West Australian Water Quality Guidelines forFresh and Marine Waters, Bulletin 711, October 1993

Gerritse, R.G., Adeney, J.A., Bates, L.E., Effect of Land Use on the Darling Plateau in WesternAustralia on Nutrient Inputs : Results of a Survey, CSIRO Division of Water Resources,Divisional Report 91/25, November 1991

Gerritse, R.G., Adeney, J.A., Bates, L.E., Nutrient Inputs from Various Land Uses on the DarlingPlateau in Western Australia : Results of a Survey, CSIRO Division of Water Resources,Divisional Report 92/3, April 1992

GHD Pty Ltd, Town of Mosman Park Master Drainage Plan Stages 1 & 2, June 1989

Golder Associates Pty Ltd (1999), Preliminary Site Assessment, Geotechnical andContamination, Infilled Quarry Former Quarry, The Boulevard City Beach, December 1999

Government of Western Australia (2001a). State Water Quality Management Strategy No. 1Framework for Implementation, Report No SWQ1, May 2001

Government of Western Australia (2001b). Bush Forever - Keeping the Bush in the City. Volume2: Directory of Bush Forever Sites.

Halpern Glik Maunsell (1995), Lake Claremont Nutrient Stripping Basin, December 1995


J2868r.doc 5127 May, 2002

Hill, A.L., Semeniuk, C.A., Semeniuk, V. & Del Marco, A. (1996) Wetlands Of The Swan CoastalPlain Volume. 2b, Wetland Mapping, Classification And Evaluation, Wetland Atlas

Hollick, Malcolm (1993), An Introduction to Project Evaluation

Hydro-Plan (1987), Groundwater Salinity Readings, Fax Report to Town of Cottesloe, July 1987

Hydro-Plan (1990), Groundwater Salinities on the Cottesloe Peninsular, June 1990

Hydro-Plan (1994), Groundwater Monitoring Data Review for the Town of Cottesloe 1994,November 1994

JDA Consultant Hydrologists (2002), Southern River / Forrestdale / Brookdale / WungongStructure Plan Urban Water Management Strategy, Volume 1 (Main Report) and 2 (TechnicalAppendices), April 2002

JDA Consultant Hydrologists (2002), Metropolitan Road Network : Potential for DirectStormwater Runoff to Wetlands and Rivers, May 2002

Kent McDowall & Associates Pty Ltd (1984), Town Centre Drainage Study Town of Cottesloe,June 1984

Kent McDowall & Associates Pty Ltd (1983), Town of Cottesloe Drainage Basin Report,December 1983

Martinick McNulty Pty Ltd (1998), Lake Monger Groundwater Study Phase 1,November 1998

McDowall Affleck Pty Ltd (1995), Town of Cottesloe Drainage Study 1995

P.E. Buck & Associates (1981), Town of Cottesloe Groundwater and Irrigation SystemRequirements Report

Pierce, D (1997), Contaminant Cycling in Lake Monger and its Implications for LakeManagement, University of WA Department of Environmental Engineering Honours Project,October 1997

Pierce, D., Davies, J., (1999), Street Sweeping Revisited - Nutrients and Metals in Particle SizeFractions of Road Sediment from Two Major Roads in Perth, Water 99 Joint Congress,Brisbane Australia July 1999.

PPK Environment & Infrastructure (2000), Perry Lakes Environmental Management Plan,September 2000

Regeneration Technology Pty Ltd (1995), Lake Monger Rehabilitation Plan East and South-EastAreas, March 1995

Swan River Trust (1999), Swan-Canning Cleanup Program Action Plan, An Action Plan to CleanUp the Swan-Canning Rivers and Estuary, May 1999

Tan H.T.H (1992), Relationships of Nutrients in Stormwater Drains to Urban CatchmentAttributes in Perth, International Symposium on Urban Stormwater Management Sydney ,February 1992

Town of Claremont (1990), Report on Recharge Basins within the Town

Town of Claremont (1998), Lake Claremont Policy, Revised 1998, report prepared for the LakeClaremont Committee

Town of Mosman Park (2001), Battling Salinity – The Holistic Approach. A Case Study at theTown of Mosman Park

Tract (WA) Pty Ltd, Michael Coates and Associates, Roberts Day Group (1997), LakeClaremont Golf Course and Environs Review, November 1997


J2868r.doc 5227 May, 2002

Water and Rivers Commission (1997) Perth Groundwater Atlas, October 1997

Water and Rivers Commission (1998) A Manual for Managing Urban Stormwater Quality inWestern Australia. August 1998.

Water Corporation (1998) Urban Main Drainage Manual – Design & Construction Requirementsfor Urban Main Drains.

Western Australia Planning Commission (1998) Perth’s Bushplan ‘Keeping the Bush in the City’.November 1998

Whelans and Halpern Glick Maunsell (1993) Water Sensitive Urban (Residential) DesignGuidelines for the Perth Metropolitan Region.

APPENDIX 1

Water Quality Guidelinesfor Toxicants

3.4.2 How guidelines are developed for toxicants

Version — October 2000 page 3.4–5

Table 3.4.1 Trigger values for toxicants at alternative levels of protection. Values in grey shading are the triggervalues applying to typical slightly–moderately disturbed systems; see table 3.4.2 and Section 3.4.2.4 for guidance onapplying these levels to different ecosystem conditions.

Chemical Trigger values for freshwater(µµµµgL-1)

Trigger values for marine water(µµµµgL-1)

Level of protection (% species) Level of protection (% species)

99% 95% 90% 80% 99% 95% 90% 80%

METALS & METALLOIDS

Aluminium pH >6.5 27 55 80 150 ID ID ID ID

Aluminium pH <6.5 ID ID ID ID ID ID ID ID

Antimony ID ID ID ID ID ID ID ID

Arsenic (As III) 1 24 94 C 360 C ID ID ID ID

Arsenic (AsV) 0.8 13 42 140 C ID ID ID ID

Beryllium ID ID ID ID ID ID ID ID

Bismuth ID ID ID ID ID ID ID ID

Boron 90 370 C 680 C 1300 C ID ID ID ID

Cadmium H 0.06 0.2 0.4 0.8 C 0.7 B 5.5 B, C 14 B, C 36 B, A

Chromium (Cr III) H ID ID ID ID 7.7 27.4 48.6 90.6

Chromium (CrVI) 0.01 1.0 C 6 A 40 A 0.14 4.4 20 C 85 C

Cobalt ID ID ID ID 0.005 1 14 150 C

Copper H 1.0 1.4 1.8 C 2.5 C 0.3 1.3 3 C 8 A

Gallium ID ID ID ID ID ID ID ID

Iron ID ID ID ID ID ID ID ID

Lanthanum ID ID ID ID ID ID ID ID

Lead H 1.0 3.4 5.6 9.4 C 2.2 4.4 6.6 C 12 C

Manganese 1200 1900C 2500C 3600C ID ID ID ID

Mercury (inorganic) B 0.06 0.6 1.9 C 5.4 A 0.1 0.4 C 0.7 C 1.4 C

Mercury (methyl) ID ID ID ID ID ID ID ID

Molybdenum ID ID ID ID ID ID ID ID

Nickel H 8 11 13 17 C 7 70 C 200 A 560A

Selenium (Total) B 5 11 18 34 ID ID ID ID

Selenium (SeIV) B ID ID ID ID ID ID ID ID

Silver 0.02 0.05 0.1 0.2 C 0.8 1.4 1.8 2.6 C

Thallium ID ID ID ID ID ID ID ID

Tin (inorganic, SnIV) ID ID ID ID ID ID ID ID

Tributyltin (as µg/L Sn) ID ID ID ID 0.0004 0.006 C 0.02 C 0.05 C

Uranium ID ID ID ID ID ID ID ID

Vanadium ID ID ID ID 50 100 160 280

Zinc H 2.4 8.0 C 15 C 31 C 7 15 C 23 C 43 C

NON-METALLIC INORGANICS

Ammonia D 320 900 C 1430 C 2300 A 500 910 1200 1700

Chlorine E 0.4 3 6 A 13 A ID ID ID ID

Cyanide F 4 7 11 18 2 4 7 14

Nitrate J 17 700 3400 C 17000 A ID ID ID ID

Hydrogen sulfide G 0.5 1.0 1.5 2.6 ID ID ID ID

ORGANIC ALCOHOLS

Ethanol 400 1400 2400 C 4000 C ID ID ID ID

Ethylene glycol ID ID ID ID ID ID ID ID

Isopropyl alcohol ID ID ID ID ID ID ID ID

CHLORINATED ALKANES

Chloromethanes

Dichloromethane ID ID ID ID ID ID ID ID

Chloroform ID ID ID ID ID ID ID ID

Carbon tetrachloride ID ID ID ID ID ID ID ID

Chloroethanes

1,2-dichloroethane ID ID ID ID ID ID ID ID

1,1,1-trichloroethane ID ID ID ID ID ID ID ID

Chapter 3 — Aquatic ecosystems

page 3.4–6 Version — October 2000




99% 95% 90% 80% 99% 95% 90% 80%

1,1,2-trichloroethane 5400 6500 7300 8400 140 1900 5800 C 18000 C

1,1,2,2-tetrachloroethane ID ID ID ID ID ID ID ID

Pentachloroethane ID ID ID ID ID ID ID ID

Hexachloroethane B 290 360 420 500 ID ID ID ID

Chloropropanes

1,1-dichloropropane ID ID ID ID ID ID ID ID



CHLORINATED ALKENES

Chloroethylene ID ID ID ID ID ID ID ID

1,1-dichloroethylene ID ID ID ID ID ID ID ID

1,1,2-trichloroethylene ID ID ID ID ID ID ID ID

1,1,2,2-tetrachloroethylene ID ID ID ID ID ID ID ID

3-chloropropene ID ID ID ID ID ID ID ID

1,3-dichloropropene ID ID ID ID ID ID ID ID

ANILINES

Aniline 8 250 A 1100 A 4800 A ID ID ID ID

2,4-dichloroaniline 0.6 7 20 60 C ID ID ID ID

2,5-dichloroaniline ID ID ID ID ID ID ID ID

3,4-dichloroaniline 1.3 3 6 C 13 C 85 150 190 260

3,5-dichloroaniline ID ID ID ID ID ID ID ID

Benzidine ID ID ID ID ID ID ID ID

Dichlorobenzidine ID ID ID ID ID ID ID ID

AROMATIC HYDROCARBONS

Benzene 600 950 1300 2000 500 C 700 C 900 C 1300 C

Toluene ID ID ID ID ID ID ID ID

Ethylbenzene ID ID ID ID ID ID ID ID

o-xylene 200 350 470 640 ID ID ID ID

m-xylene ID ID ID ID ID ID ID ID

p-xylene 140 200 250 340 ID ID ID ID

m+p-xylene ID ID ID ID ID ID ID ID

Cumene ID ID ID ID ID ID ID ID

Polycyclic Aromatic Hydrocarbons

Naphthalene 2.5 16 37 85 50 C 70 C 90 C 120 C

Anthracene B ID ID ID ID ID ID ID ID

Phenanthrene B ID ID ID ID ID ID ID ID

Fluoranthene B ID ID ID ID ID ID ID ID

Benzo(a)pyrene B ID ID ID ID ID ID ID ID

Nitrobenzenes

Nitrobenzene 230 550 820 1300 ID ID ID ID

1,2-dinitrobenzene ID ID ID ID ID ID ID ID



1,3,5-trinitrobenzene ID ID ID ID ID ID ID ID

1-methoxy-2-nitrobenzene ID ID ID ID ID ID ID ID

1-methoxy-4-nitrobenzene ID ID ID ID ID ID ID ID

1-chloro-2-nitrobenzene ID ID ID ID ID ID ID ID



1-chloro-2,4-dinitrobenzene ID ID ID ID ID ID ID ID

1,2-dichloro-3-nitrobenzene ID ID ID ID ID ID ID ID









99% 95% 90% 80% 99% 95% 90% 80%

1,2,4,5-tetrachloro-3-nitrobenzene ID ID ID ID ID ID ID ID

1,5-dichloro-2,4-dinitrobenzene ID ID ID ID ID ID ID ID

1,3,5-trichloro-2,4-dinitrobenzene ID ID ID ID ID ID ID ID

1-fluoro-4-nitrobenzene ID ID ID ID ID ID ID ID

Nitrotoluenes

2-nitrotoluene ID ID ID ID ID ID ID ID



2,3-dinitrotoluene ID ID ID ID ID ID ID ID

2,4-dinitrotoluene 16 65 C 130 C 250 C ID ID ID ID

2,4,6-trinitrotoluene 100 140 160 210 ID ID ID ID

1,2-dimethyl-3-nitrobenzene ID ID ID ID ID ID ID ID

1,2-dimethyl-4-nitrobenzene ID ID ID ID ID ID ID ID

4-chloro-3-nitrotoluene ID ID ID ID ID ID ID ID

Chlorobenzenes and Chloronaphthalenes

Monochlorobenzene ID ID ID ID ID ID ID ID

1,2-dichlorobenzene 120 160 200 270 ID ID ID ID

1,3-dichlorobenzene 160 260 350 520 C ID ID ID ID

1,4-dichlorobenzene 40 60 75 100 ID ID ID ID

1,2,3-trichlorobenzene B 3 10 16 30 C ID ID ID ID

1,2,4-trichlorobenzene B 85 170C 220C 300C 20 80 140 240

1,3,5-trichlorobenzene B ID ID ID ID ID ID ID ID

1,2,3,4-tetrachlorobenzene B ID ID ID ID ID ID ID ID



Pentachlorobenzene B ID ID ID ID ID ID ID ID

Hexachlorobenzene B ID ID ID ID ID ID ID ID

1-chloronaphthalene ID ID ID ID ID ID ID ID

Polychlorinated Biphenyls (PCBs) & Dioxins

Capacitor 21 B ID ID ID ID ID ID ID ID

Aroclor 1016 B ID ID ID ID ID ID ID ID



Aroclor 1242 B 0.3 0.6 1.0 1.7 ID ID ID ID


Aroclor 1254 B 0.01 0.03 0.07 0.2 ID ID ID ID




2,3,4’-trichlorobiphenyl B ID ID ID ID ID ID ID ID

4,4’-dichlorobiphenyl B ID ID ID ID ID ID ID ID

2,2’,4,5,5’-pentachloro-1,1’-biphenylB ID ID ID ID ID ID ID ID

2,4,6,2’,4’,6’-hexachlorobiphenyl B ID ID ID ID ID ID ID ID

Total PCBs B ID ID ID ID ID ID ID ID

2,3,7,8-TCDD B ID ID ID ID ID ID ID ID

PHENOLS and XYLENOLS

Phenol 85 320 600 1200 C 270 400 520 720

2,4-dimethylphenol ID ID ID ID ID ID ID ID

Nonylphenol ID ID ID ID ID ID ID ID

2-chlorophenol T 340 C 490 C 630 C 870 C ID ID ID ID

3-chlorophenol T ID ID ID ID ID ID ID ID

4-chlorophenol T 160 220 280 C 360 C ID ID ID ID

2,3-dichlorophenol T ID ID ID ID ID ID ID ID

2,4-dichlorophenol T 120 160 C 200 C 270 C ID ID ID ID






99% 95% 90% 80% 99% 95% 90% 80%





2,3,4-trichlorophenol T ID ID ID ID ID ID ID ID



2,4,5-trichlorophenol T,B ID ID ID ID ID ID ID ID

2,4,6-trichlorophenol T,B 3 20 40 95 ID ID ID ID

2,3,4,5-tetrachlorophenol T,B ID ID ID ID ID ID ID ID

2,3,4,6- tetrachlorophenol T,B 10 20 25 30 ID ID ID ID

2,3,5,6- tetrachlorophenol T,B ID ID ID ID ID ID ID ID

Pentachlorophenol T,B 3.6 10 17 27 A 11 22 33 55 A

Nitrophenols

2-nitrophenol ID ID ID ID ID ID ID ID



2,4-dinitrophenol 13 45 80 140 ID ID ID ID

2,4,6-trinitrophenol ID ID ID ID ID ID ID ID

ORGANIC SULFUR COMPOUNDS

Carbon disulfide ID ID ID ID ID ID ID ID

Isopropyl disulfide ID ID ID ID ID ID ID ID

n-propyl sulfide ID ID ID ID ID ID ID ID

Propyl disulfide ID ID ID ID ID ID ID ID

Tert-butyl sulfide ID ID ID ID ID ID ID ID

Phenyl disulfide ID ID ID ID ID ID ID ID

Bis(dimethylthiocarbamyl)sulfide ID ID ID ID ID ID ID ID

Bis(diethylthiocarbamyl)disulfide ID ID ID ID ID ID ID ID

2-methoxy-4H-1,3,2-benzodioxaphosphorium-2-sulfide

ID ID ID ID ID ID ID ID

Xanthates

Potassium amyl xanthate ID ID ID ID ID ID ID ID

Potassium ethyl xanthate ID ID ID ID ID ID ID ID

Potassium hexyl xanthate ID ID ID ID ID ID ID ID

Potassium isopropyl xanthate ID ID ID ID ID ID ID ID

Sodium ethyl xanthate ID ID ID ID ID ID ID ID

Sodium isobutyl xanthate ID ID ID ID ID ID ID ID

Sodium isopropyl xanthate ID ID ID ID ID ID ID ID

Sodium sec-butyl xanthate ID ID ID ID ID ID ID ID

PHTHALATES

Dimethylphthalate 3000 3700 4300 5100 ID ID ID ID

Diethylphthalate 900 1000 1100 1300 ID ID ID ID

Dibutylphthalate B 9.9 26 40.2 64.6 ID ID ID ID

Di(2-ethylhexyl)phthalate B ID ID ID ID ID ID ID ID

MISCELLANEOUS INDUSTRIAL CHEMICALS

Acetonitrile ID ID ID ID ID ID ID ID

Acrylonitrile ID ID ID ID ID ID ID ID

Poly(acrylonitrile-co-butadiene-co-styrene)

200 530 800 C 1200 C 200 250 280 340

Dimethylformamide ID ID ID ID ID ID ID ID

1,2-diphenylhydrazine ID ID ID ID ID ID ID ID

Diphenylnitrosamine ID ID ID ID ID ID ID ID

Hexachlorobutadiene ID ID ID ID ID ID ID ID

Hexachlorocyclopentadiene ID ID ID ID ID ID ID ID






99% 95% 90% 80% 99% 95% 90% 80%

Isophorone ID ID ID ID ID ID ID ID

ORGANOCHLORINE PESTICIDES

Aldrin B ID ID ID ID ID ID ID ID

Chlordane B 0.03 0.08 0.14 0.27 C ID ID ID ID

DDE B ID ID ID ID ID ID ID ID

DDT B 0.006 0.01 0.02 0.04 ID ID ID ID

Dicofol B ID ID ID ID ID ID ID ID

Dieldrin B ID ID ID ID ID ID ID ID

Endosulfan B 0.03 0.2 A 0.6 A 1.8 A 0.005 0.01 0.02 0.05 A

Endosulfan alpha B ID ID ID ID ID ID ID ID

Endosulfan beta B ID ID ID ID ID ID ID ID

Endrin B 0.01 0.02 0.04 C 0.06 A 0.004 0.008 0.01 0.02

Heptachlor B 0.01 0.09 0.25 0.7 A ID ID ID ID

Lindane 0.07 0.2 0.4 1.0 A ID ID ID ID

Methoxychlor B ID ID ID ID ID ID ID ID

Mirex B ID ID ID ID ID ID ID ID

Toxaphene B 0.1 0.2 0.3 0.5 ID ID ID ID

ORGANOPHOSPHORUS PESTICIDES

Azinphos methyl 0.01 0.02 0.05 0.11 A ID ID ID ID

Chlorpyrifos B 0.00004 0.01 0.11 A 1.2 A 0.0005 0.009 0.04A 0.3 A

Demeton ID ID ID ID ID ID ID ID

Demeton-S-methyl ID ID ID ID ID ID ID ID

Diazinon 0.00003 0.01 0.2 A 2 A ID ID ID ID

Dimethoate 0.1 0.15 0.2 0.3 ID ID ID ID

Fenitrothion 0.1 0.2 0.3 0.4 ID ID ID ID

Malathion 0.002 0.05 0.2 1.1 A ID ID ID ID

Parathion 0.0007 0.004 C 0.01 C 0.04 A ID ID ID ID

Profenofos B ID ID ID ID ID ID ID ID

Temephos B ID ID ID ID 0.0004 0.05 0.4 3.6 A

CARBAMATE & OTHER PESTICIDES

Carbofuran 0.06 1.2 A 4 A 15 A ID ID ID ID

Methomyl 0.5 3.5 9.5 23 ID ID ID ID

S-methoprene ID ID ID ID ID ID ID ID

PYRETHROIDS

Deltamethrin ID ID ID ID ID ID ID ID

Esfenvalerate ID 0.001* ID ID ID ID ID ID

HERBICIDES & FUNGICIDES

Bypyridilium herbicides

Diquat 0.01 1.4 10 80 A ID ID ID ID

Paraquat ID ID ID ID ID ID ID ID

Phenoxyacetic acid herbicides

MCPA ID ID ID ID ID ID ID ID

2,4-D 140 280 450 830 ID ID ID ID

2,4,5-T 3 36 100 290 A ID ID ID ID

Sulfonylurea herbicides

Bensulfuron ID ID ID ID ID ID ID ID

Metsulfuron ID ID ID ID ID ID ID ID

Thiocarbamate herbicides

Molinate 0.1 3.4 14 57 ID ID ID ID

Thiobencarb 1 2.8 4.6 8 C ID ID ID ID

Thiram 0.01 0.2 0.8 C 3 A ID ID ID ID

Triazine herbicides

Amitrole ID ID ID ID ID ID ID ID

Atrazine 0.7 13 45 C 150 C ID ID ID ID






99% 95% 90% 80% 99% 95% 90% 80%

Hexazinone ID ID ID ID ID ID ID ID

Simazine 0.2 3.2 11 35 ID ID ID ID

Urea herbicides

Diuron ID ID ID ID ID ID ID ID

Tebuthiuron 0.02 2.2 20 160 C ID ID ID ID

Miscellaneous herbicides

Acrolein ID ID ID ID ID ID ID ID

Bromacil ID ID ID ID ID ID ID ID

Glyphosate 370 1200 2000 3600 A ID ID ID ID

Imazethapyr ID ID ID ID ID ID ID ID

Ioxynil ID ID ID ID ID ID ID ID

Metolachlor ID ID ID ID ID ID ID ID

Sethoxydim ID ID ID ID ID ID ID ID

Trifluralin B 2.6 4.4 6 9 A ID ID ID ID

GENERIC GROUPS OF CHEMICALS

Surfactants

Linear alkylbenzene sulfonates (LAS) 65 280 520 C 1000 C ID ID ID ID

Alcohol ethoxyolated sulfate (AES) 340 650 850 C 1100 C ID ID ID ID

Alcohol ethoxylated surfactants (AE) 50 140 220 360 C ID ID ID ID

Oils & Petroleum Hydrocarbons ID ID ID ID ID ID ID ID

Oil Spill Dispersants

BP 1100X ID ID ID ID ID ID ID ID

Corexit 7664 ID ID ID ID ID ID ID ID

Corexit 8667 ID ID ID ID ID ID ID

Corexit 9527 ID ID ID ID 230 1100 2200 4400 A

Corexit 9550 ID ID ID ID ID ID ID ID

Notes: Where the final water quality guideline to be applied to a site is below current analytical practical quantitation limits, see Section 3.4.3.3 forguidance.

Most trigger values listed here for metals and metalloids are High reliability figures, derived from field or chronic NOEC data (see 3.4.2.3 for reference toVolume 2). The exceptions are Moderate reliability for freshwater aluminium (pH >6.5), manganese and marine chromium (III).

Most trigger values listed here for non-metallic inorganics and organic chemicals are Moderate reliability figures, derived from acute LC50 data (see3.4.2.3 for reference to Volume 2). The exceptions are High reliability for freshwater ammonia, 3,4-DCA, endosulfan, chlorpyrifos, esfenvalerate,tebuthiuron, three surfactants and marine for 1,1,2-TCE and chlorpyrifos.

* = High reliability figure for esfenvalerate derived from mesocosm NOEC data (no alternative protection levels available).

A = Figure may not protect key test species from acute toxicity (and chronic) — check Section 8.3.7 for spread of data and its significance. ‘A’ indicatesthat trigger value > acute toxicity figure; note that trigger value should be <1/3 of acute figure (Section 8.3.4.4).

B = Chemicals for which possible bioaccumulation and secondary poisoning effects should be considered (see Sections 8.3.3.4 and 8.3.5.7).

C = Figure may not protect key test species from chronic toxicity (this refers to experimental chronic figures or geometric mean for species) — checkSection 8.3.7 for spread of data and its significance. Where grey shading and ‘C’ coincide, refer to text in Section 8.3.7.

D = Ammonia as TOTAL ammonia as [NH3-N] at pH 8. For changes in trigger value with pH refer to Section 8.3.7.2.

E = Chlorine as total chlorine, as [Cl]; see Section 8.3.7.2.

F = Cyanide as un-ionised HCN, measured as [CN]; see Section 8.3.7.2.

G = Sulfide as un-ionised H2S, measured as [S]; see Section 8.3.7.2.

H = Chemicals for which algorithms have been provided in table 3.4.3 to account for the effects of hardness. The values have been calculated using ahardness of 30 mg/L CaCO3. These should be adjusted to the site-specific hardness (see Section 3.4.3).

J = Figures protect against toxicity and do not relate to eutrophication issues. Refer to Section 3.3 if eutrophication is the issue of concern.

ID = Insufficient data to derive a reliable trigger value. Users advised to check if a low reliability value or an ECL is given in Section 8.3.7.

T = Tainting or flavour impairment of fish flesh may possibly occur at concentrations below the trigger value. See Sections 4.4.5.3/3 and 8.3.7.

APPENDIX 2

Tabulation of Sub Catchment Land UseCharacteristics

Town of Cambridge

Total Road Lengths (km) Land Use

Secondary Road

Primary Road

Freeway Barracks

Cemetery

Commercial

Hospital

Light Industrial

Municipal Purposes

Parks & Recreation

Public Purpose

Railways & Roads

Residential

Residential & Commercial

Special Use

Wasterwater Treatment Plant

Wetland

CA 1 Ocean / Dunes 143.6 100% 0%

CA 2 Infiltration Basin / Swale 48.3 0.5 1.0 28% 72%

CA 3 Infiltration Basin / Swale 7.0 1% 50% 49%

CA 4 Infiltration Basin / Swale 36.1 0.4 26% 74%

CA 5 * Infiltration Basin / Swale 11.5 13% 87%

CA 6 Parks / Reserves 98.6 1.5 0.8 0% 31% 4% 65%


CA 8 * Infiltration Basin / Swale 3.0 100%

CA 9 Parks / Reserves 9.4 100%

CA 10 Infiltration Basin / Swale 33.8 100%

CA 11 Infiltration Basin / Swale 94.5 0.5 0.8 22% 8% 70%

CA 12 Parks / Reserves 4.4 73% 27%

CA 13 Parks / Reserves 9.4 0.3 50% 29% 21%

CA 14 Infiltration Basin / Swale 49.2 1.4 60% 5% 35%

CA 15 Infiltration Basin / Swale 49.2 1.4 0.6 56% 1% 43%


CA 17 Infiltration Basin / Swale 112.9 0.2 1.7 82% 18%

CA 18 Parks / Reserves 32.9 0.3 85% 15%


CA 20 Infiltration Basin / Swale 7.8 2% 0% 98%

CA 21 Parks / Reserves 33.1 53% 47% 0%



CA 24 * Infiltration Basin / Swale 94.9 0.6 0.6 97% 3%

CA 25 * Parks / Reserves 13.4 0.1 1% 99%

CA 26 * Parks / Reserves 18.1 81% 19%

CA 27 * Infiltration Basin / Swale 21.1 1.1 84% 4% 12%

CA 28 * Ocean / Dunes via Comp Bas 429.1 1 2 2 6.4 1% 48% 22% 26% 3%


CA 30 * Infiltration Basin / Swale 5.2 0.2 100%

CA 31 Infiltration Basin / Swale 4.7 100%

CA 32 Ocean / Dunes via Comp Bas 21.8 0.3 9% 91%

CA 33 River via Comp Basin 26.4 0.4 0% 58% 42%

CA 34 River via Comp Basin 83.4 2.0 10% 10% 0% 80%

CA 35 River via Comp Basin 20.7 0.6 0% 22% 78%

CA 36 Ocean / Dunes via Comp Bas 25.5 1 1.7 24% 6% 3% 4% 0% 63%

CA 37 River 63.4 2.6 1.4 16% 12% 0% 17% 55%

CA 38 * River via Comp Basin 12.6 1.3 43% 57%

CA - Lake Monger River 67.9 0% 100%

City of Stirling

ST 1 Infiltration Basin / Swale 5.7 35% 65%

ST 2 Infiltration Basin / Swale 12.6 0.2 10% 29% 61%ST 3 Ocean / Dunes via Comp Bas 191.2 1 5.8 0.1 1% 5% 3% 0% 89% 1%

Remediated Site

Fuel Storag

eSub Catchment Sub Catchment Discharge

Point Land Use

Area (ha)

Page 1 of 6

Town of Claremont


Secondary Road

Primary Road

Freeway Barracks

Cemetery

Commercial

Hospital

Light Industrial

Municipal Purposes

Parks & Recreation

Public Purpose

Railways & Roads

Residential


Special Use


Wetland

CL 1 * Infiltration Basin / Swale 21.7 0.3 8% 51% 41%

CL 2 * Lake 163.1 2 1 1.2 0% 1% 35% 10% 0% 43% 10%

CL 3 Infiltration Basin / Swale 18.4 0.2 1% 59% 0% 40%

CL 4 Infiltration Basin / Swale 8.3 0.3 6% 2% 91%

CL 5 Infiltration Basin / Swale 3.5 0.0 9% 91%

CL 6 Infiltration Basin / Swale 21.4 1 1 0.0 0% 91% 8% 0%

CL 7 * Soakwell 1.7 11% 89%

CL 8 * Infiltration Basin / Swale 12.8 7% 13% 80%

CL 9 Infiltration Basin / Swale 8.3 9% 91%

CL 10 * Soakwell 6.0 2% 98%

CL 11 * Infiltration Basin / Swale 1.4 0.1 57% 43%

CL 12 Infiltration Basin / Swale 12.1 1 0.0 2% 98%


CL 14 Soakwell 5.4 0.0 1% 38% 3% 58%

CL 15 * Infiltration Basin / Swale 12.7 2% 2% 96%

CL 16 Infiltration Basin / Swale 3.7 1 1 0.4 55% 1% 44%

CL 17 Infiltration Basin / Swale 2.2 0.2 19% 20% 60%

CL 18 Soakwell 7.2 0.6 16% 1% 11% 72%

CL 19 * Infiltration Basin / Swale 25.4 0.2 0.5 27% 5% 68%


CL 21 * River 128.1 1 2.1 1.7 11% 1% 10% 15% 62% 0%

CL 22 Infiltration Basin / Swale 9.5 0.1 100%

CL 23 * Soakwell 11.0 84% 16%

CL 24 River 7.4 29% 71%

CL 25 * River 18.5 0.1 12% 1% 86%CL - Railway ReserveRailway Reserves 16.5 1 1 2.3 3% 95% 2%

Remediated Site

Fuel Storag

e

Potential

Contamination SitesSub Catchment Sub Catchment Discharge

Area (ha)

Page 2 of 6

Town of Cottesloe


Secondary Road

Primary Road

Freeway Barracks

Cemetery

Commercial

Hospital

Light Industrial

Municipal Purposes

Parks & Recreation

Public Purpose

Railways & Roads

Residential


Special Use


Wetland

CO 1 Ocean / Dunes 4.7 99% 1%

CO 2 Infiltration Basin / Swale 0.4 100%

CO 3 Infiltration Basin / Swale 11.8 1% 99%

CO 4 * Infiltration Basin / Swale 13.5 6% 94%

CO 5 * Infiltration Basin / Swale 17.7 1% 99%


CO 7 Ocean / Dunes 7.8 0.0 60% 40%






CO 13 Infiltration Basin / Swale 20.4 2 0.1 0% 0% 100%

CO 14 Infiltration Basin / Swale 4.1 0.3 0.1 7% 93%

CO 15 * Infiltration Basin / Swale 0.4 0.0 0.1 48% 52%

CO 16 Railway Reserves 3.8 1 1 0.7 14% 5% 80%

CO 17 Railway Reserves 13.7 2% 4% 9% 6% 79%

CO 18 Infiltration Basin / Swale 1.2 0.0 43% 0% 56% 1%

CO 19 Infiltration Basin / Swale 13.7 1 0.3 0.3 11% 89%

CO 20 Ocean / Dunes 11.0 1 1 7% 51% 18% 24%


CO 22 Infiltration Basin / Swale 4.0 0% 2% 94% 4%

CO 23 Soakwell 1.4 55% 45%



CO 26 Infiltration Basin / Swale 22.8 2 1 0.4 4% 1% 2% 93%

CO 27 Railway Reserves 0.8 0.1 6% 94%

CO 28 Railway Reserves 6.7 0.1 3% 1% 6% 90%

CO 29 Soakwell 1.9 100%

CO 30 Soakwell 0.3 3% 97%

CO 31 Ocean / Dunes 4.2 100%

CO 32 Infiltration Basin / Swale 35.1 5% 75% 20%



CO 35 Infiltration Basin / Swale 9.9 0.4 2% 4% 94%

CO 36 Infiltration Basin / Swale 10.7 0.2 3% 4% 76% 16% 1%

CO 37 Infiltration Basin / Swale 7.1 1 93% 7%

CO 38 Ocean / Dunes 20.6 28% 72%

CO 39 Railway Reserves 21.9 0.8 0% 3% 97%

CO 40 Ocean / Dunes 16.5 24% 21% 56%



CO 43 Railway Reserves 4.3 0.5 37% 6% 57%

CO 44 Ocean / Dunes 10.1 0.1 34% 7% 0% 59%


CO 46 Ocean / Dunes 3.2 0.3 91% 9% 0%CO - Railway Reserv Railway Reserves 28.8 0.1 0.0 0% 100% 0%

Remediated Site

Fuel Storag

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Potential

Contamination SitesSub Catchment Sub Catchment Discharge

Area (ha)

Page 3 of 6

Town of Mosman Park


Secondary Road

Primary Road

Freeway Barracks

Cemetery

Commercial

Hospital

Light Industrial

Municipal Purposes

Parks & Recreation

Public Purpose

Railways & Roads

Residential


Special Use


Wetland

MP 1 Infiltration Basin / Swale 25.4 0.9 13% 2% 3% 83%

MP 2 Infiltration Basin / Swale 24.8 0% 8% 16% 76%

MP 3 * River 18.4 38% 10% 52%

MP 4 River 0.8 95% 5%

MP 5 River 1.5 100%

MP 6 Infiltration Basin / Swale 22.3 7% 12% 16% 64%

MP 7 River 1.4 100%

MP 8 Infiltration Basin / Swale 60.3 1 1 0.4 0% 18% 11% 0% 70%

MP 9 Infiltration Basin / Swale 46.9 2% 5% 92%

MP 10 River 2.4 74% 26%

MP 11 River 1.0 59% 41%

MP 12 River 1.8 11% 89%

MP 13 River 6.3 6% 94%

MP 14 River 1.0 20% 80%

MP 15 River 2.8 3% 97%

MP 16 River 1.0 16% 84%

MP 17 River 1.7 10% 90%

MP 18 Ocean / Dunes 2.4 2 100%

MP 19 Soakwell 3.8 0.6 29% 71%

MP 20 Railway Reserves 1.1 100% 0%

MP 21 Parks / Reserves 6.0 0.3 100% 0% 0%


MP 23 Infiltration Basin / Swale 9.7 1 1 19% 15% 66%


MP 25 Infiltration Basin / Swale 1.8 92% 8%



MP 28 River 3.4 91% 9%

MP 29 River 0.6 100%

MP 30 River 5.7 44% 56%

MP 31 River 2.1 67% 33%

MP 32 River 2.2 98% 2%

MP 33 Infiltration Basin / Swale 10.4 0.2 20% 80%

MP 34 River 15.7 1 1 16% 19% 66%

MP 35 Infiltration Basin / Swale 8.3 1 59% 14% 27%

MP 36 Parks / Reserves 8.2 1 100%

MP 37 Soakwell 0.5 1% 99%

MP 38 Soakwell 5.2 39% 27% 34%

MP 39 Infiltration Basin / Swale 13.6 1 48% 1% 51%

MP - Railway Reserv Railway Reserves 9.9 2 0.6 100%

City of Fremantle FR 1 River 4.9

Remediated Site

Fuel Storag

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Potential

Contamination Sites

Area (ha)

Page 4 of 6

City of Nedlands


Secondary Road

Primary Road

Freeway Barracks

Cemetery

Commercial

Hospital

Light Industrial

Municipal Purposes

Parks & Recreation

Public Purpose

Railways & Roads

Residential


Special Use


Wetland

NE 1 Ocean / Dunes 192.3 2 26% 74%

NE 2 Ocean / Dunes 13.8 69% 31%

NE 3 Ocean / Dunes 0.9 58% 42%

NE 4 Infiltration Basin / Swale 25.5 3% 43% 54%

NE 5 * Parks / Reserves 57.6 0.1 1.4 41% 52% 8% 0%


NE 7 Infiltration Basin / Swale 1.6 70% 22% 3% 5%

NE 8 Infiltration Basin / Swale 15.2 27% 73%

NE 9 * Infiltration Basin / Swale 4.8 0.9 2% 4% 94%

NE 10 * Infiltration Basin / Swale 38.9 1 0.3 29% 71%

NE 11 * Parks / Reserves 13.3 82% 18%

NE 12 Parks / Reserves 24.7 96% 4%


NE 14 Infiltration Basin / Swale 26.7 0.4 6% 94%

NE 15 * Soakwell 19.5 0.9 11% 1% 88%


NE 17 Parks / Reserves 33.0 1 0.2 0% 4% 1% 95% 0%

NE 18 * Infiltration Basin / Swale 50.4 0.2 0% 2% 6% 88% 4%

NE 19 Infiltration Basin / Swale 37.3 31% 6% 33% 29% 2%

NE 20 Infiltration Basin / Swale 12.8 1 0.4 71% 0% 29%

NE 21 Infiltration Basin / Swale 19.8 0.5 52% 1% 29% 18%

NE 22 * Infiltration Basin / Swale 2.6 0.3 0% 100%

NE 23 Soakwell 14.0 0.2 17% 31% 52%

NE 24 Infiltration Basin / Swale 147.4 4 1.9 13% 4% 25% 0% 43% 14%

NE 25 * Infiltration Basin / Swale 27.4 0.7 15% 6% 61% 18%

NE 26 * Infiltration Basin / Swale 22.7 1.1 58% 4% 4% 7% 28%

NE 27 Infiltration Basin / Swale 90.3 3 2 0.1 52% 1% 3% 6% 2% 0% 36%


NE 29 Soakwell 24.8 81% 19%

NE 30 * Ocean / Dunes via Comp Bas 140.4 1 4.5 2% 0% 32% 12% 11% 0% 43% 0%

NE 31 Soakwell 10.6 0.3 14% 34% 52%

NE 32 * Infiltration Basin / Swale 13.4 0.4 1% 99%


NE 34 Infiltration Basin / Swale 6.0 0.2 35% 65%

NE 35 Infiltration Basin / Swale 6.1 0.2 42% 0% 58%

NE 36 * Infiltration Basin / Swale 67.5 1 0.3 5% 10% 84%

NE 37 Infiltration Basin / Swale 35.0 0.1 0.6 13% 0% 86%

NE 38 Infiltration Basin / Swale 34.2 1 0% 4% 96%

NE 39 * Infiltration Basin / Swale 104.1 1 1 15% 85%

NE 40 River 0.5 7% 93%

NE 41 River 5.8 2% 98%

NE 42 * Soakwell 18.3 100%

NE 43 River 1.8 2% 98%

NE 44 River 6.3 20% 80%

NE 45 River 58.2 33% 67%

NE 46 Infiltration Basin / Swale 6.9 100%

NE 47 River 3.2 4% 96%

NE 48 River 2.8 7% 93%

NE 49 River 3.2 36% 64%

NE 50 Infiltration Basin / Swale 51.0 10% 90%

NE 51 River 32.4 2 58% 42%

NE 52 River 39.5 34% 66%

NE 53 River 51.8 1 2% 46% 53%NE - Railway ReservRailway Reserves 16.0 1 1.4 7% 84% 4% 5%

Fuel Storag

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Remediated SiteSub Catchment Sub Catchment Discharge

Area (ha)

Potential

Contamination Sites

Page 5 of 6

Shire of Peppermint Grove


Secondary Road

Primary Road

Freeway Barracks

Cemetery

Commercial

Hospital

Light Industrial

Municipal Purposes

Parks & Recreation

Public Purpose

Railways & Roads

Residential


Special Use


Wetland

PG 1 Infiltration Basin / Swale 43.2 1.0 10% 9% 81% 0% 0%

PG 2 * River 43.8 21% 5% 74%

PG 3 Infiltration Basin / Swale 2.1 0.1 55% 6% 39%

PG 4 * Infiltration Basin / Swale 13.2 1 0.4 10% 22% 2% 66%

PG 5 * Infiltration Basin / Swale 14.1 7% 93%PG - Railway ReservRailway Reserves 0.8 1% 0% 99% 0%

City of Subiaco


Secondary Road

Primary Road

Freeway Barracks

Cemetery

Commercial

Hospital

Light Industrial

Municipal Purposes

Parks & Recreation

Public Purpose

Railways & Roads

Residential


Special Use


Wetland

SU 1 * River via Comp Basin 243.8 3 6 2 7.8 11% 0% 12% 5% 70% 1% 0%

SU 2 * River via Comp Basin 50.4 8 2 0.9 43% 5% 7% 4% 0% 34% 6%

SU 3 * Ocean / Dunes via Comp Bas 241.6 4 2 10.0 11% 4% 11% 8% 0% 57% 9%

SU 4 * Ocean / Dunes via Comp Bas 85.9 1.7 62% 2% 15% 19% 2%

SU 5 Ocean / Dunes via Comp Bas 151.4 1 2 3.5 3% 8% 0% 87% 0% 2%

SU 6 * River 113.4 1 1.9 1.1 4% 2% 12% 81%

SU 7 * River 88.5 1 1.8 7% 0% 7% 6% 80%

SU 8 River 19.3 0.2 6% 94%

SU 9 River 21.1 0% 100% 0%

SU 10 River 21.3 0.9 100% 0%SU - Railway ReserveRailway Reserves 12.2 0.1 0% 100% 0%

Fuel Storag

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Fuel Storag

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Remediated Site

Remediated Site

Area (ha)Sub Catchment Sub Catchment Discharge

Potential

Contamination Sites

Sub Catchment Sub Catchment DischargeArea (ha)

Potential

Contamination Sites

Page 6 of 6

APPENDIX 3

Nutrient Input Decision Support SystemModelling

Total Nutrient Input - No WSUD (kg/yr) 1,545

Nutrient Input Decision Support System Reduction due to Source Control (kg/yr) 454

Version 1.1 February 2001 Percentage Overall Reduction 29.4%

JDA Consultant Hydrologists Pecentage Development Reduction 29.4%

Report Date : 18-Jul-02 Cost of Selected Program ($/kg/yr) $191.9

Local Authority

Catchment Name

Catchment Area 100 ha

Key AssumptionsLand Use Lots (<=R20) 15.0% Residential Major Source of Nutrient Input

Lots (>R20) 15.0% <=R20 adopts R15 data, >R20 R35 data

POS (active) 10.0% Road reserve assumed at 30% of residential area

POS (passive) 25.0%

Road Res 30.0% Total 95.0% Industrial/ Commercial 5.0%

Nutrient Input Without WSUD

Lots <R20 Garden 29.70 kg/net ha/yr 4.46 kg/gross ha/yr 446 kg/yr 28.8%

Lawn 14.00 2.10 210 13.6%

Pet Waste 3.96 0.59 59 3.8%

Car Wash 0.13 0.02 2 0.1%

Sub Total 47.79 7.17 717 46.4%

Lots >R20 Garden 8.10 kg/net ha/yr 1.22 kg/gross ha/yr 122 kg/yr 7.9%

Lawn 3.50 0.53 53 3.4%

Pet Waste 0.00 0.00 0 0.0%

Car Wash 0.13 0.02 2 0.1%

Sub Total 11.73 1.76 176 11.4%

POS Garden/Lawn 2.60 kg/ha POS/yr 0.26 kg/gross ha/yr 26 kg/yr 1.7%

Pet Waste <R20 1.02 0.10 10 0.7%

Pet Waste >R20 1.61 0.16 16 1.0%

Sub Total 5.23 0.52 52 3.4%

Road Road Reserves 20.00 kg/ha RR/yr 6.00 kg/gross ha/yr 600 kg/yr 38.8%

Reserve Sub Total 20.00 6.00 600 38.8%

Total 15.45 kg/gross ha/yr 1,545 kg/yr 100.0%

Development Nutrient Removal via Source Control

Education Effectiveness 20%

% Area of Removal Removal Removal Capital Operating Cost

Influence kg/gross ha/yr kg/yr % Cost $ Cost $/yr $/kg/yr

Native Gardens (Lots - Garden) 20% 1.13 113 7.3% $0 $0 $0.0

Native Gardens (Lots - Lawn) 20% 0.53 53 3.4% $0 $0 $0.0

Native Gardens (POS) 20% 0.05 5 0.3% $0 $0 $0.0

Community Education : Fertiliser 100% 2.10 210 13.6% $0 $375 $1.8

Community Education : Pet Waste 100% 0.17 17 1.1% $0 $493 $28.7

Community Education : Car Wash 100% 0.01 1 0.1% $0 $375 $476.8

Street Sweeping : Residenital Areas 100% 0.26 26 1.7% $0 $12,375 $476.4

Totals 4.25 425 27.5% $0 $13,618 $32.0

Development Nutrient Removal via In-Transit Control

% Area of Removal Removal Removal Capital Operating Cost

Influence kg/gross ha/yr kg/yr % Cost $ Cost $/yr $/kg/yr

Gross Pollutant Traps 100% 0.14 14 0.9% $178,600 $6,840 $1,211.1

Water Pollution Control Ponds 100% 0.14 14 0.9% $757,493 $10,521 $3,911.8

Total 0.29 29 1.9% $936,093 $17,361 $2,552.6

Net Nutrient Input

kg/gross ha/yr kg/yr %Nutrient Input Development without WSUD 15.45 1,545 100.0% Capital Operating Cost

Cost $ Cost $/yr $/kg/yrRemoval via Source Control 4.25 425 27.5% $0 $13,618 $32.0Removal via In-Transit Control 0.29 29 1.9% $936,093 $17,361 $2,552.6Total Removal 4.54 454 29.4% $936,093 $30,978 $191.9

Net Nutrient Input 10.91 1,091 70.6%

Community Education : Fertiliser

Native Gardens (Lots - Garden) Street Sweeping

Water Pollution Control PondGross Pollutant Trap

Native Gardens (POS)Native Gardens (Lots - Lawn)

Community Education : Pet Waste Community Education : Car Wash

Total Phosphorus

Total Nitrogen

NiDSS WESROC

SAMPLE NiDSS OUTPUT ONLY

NiDSS Core Data & Cost CalculationsNutrient Input Decision Support SystemVersion 1.1 November 2001

Analysis Type (1,2) 1 TP 1 Total Phosphorus

2 Total Nitrogen

Av Density Assumed =<R20 15 lots/ha

Av Density Assumed >R20 35 lots/ha

Discount Rate 6%

Community Education Information

“Who Cares About the Environment ?” (NSW EPA, 2000) Survey 17% stated environment one of two most important issues for govt to addressOf these 27% stated water as most important environmental issue17% stated education most important issue to protect environmentImpact assumed to reduce fertiliser applications to minimum rates

Fertiliser Application Information/Assumptions

Lots assumed fertilised by property ownerMinor Road Reserves fertilised by property owner (verge assumed 40% road reserve)Major Road Reserves fertilised by local authority (verge assumed 40% road reserve)Active POS fertilised by local authorityPassive POS not fertilisedRural Land Use and Poultry Farms have no reductions due to WSUD applied

Pet Waste

Data Source Pets per lot and disposal via JDA Survey (2001)

TP & TN application via Gerritse at al (1991)

Cost Estimate via JDA. Distribution cost and frequency is for brochure, bag cost is for POS's

Application Rates

Survey Results

TN TP TN or TP Pets Per Lot

(kg/yr) (kg/yr) specified R15 R35 Cost Calculation

Cats 0.90 0.20 0.20 0.24 0.16 <=R20 >R20

Sml Dogs 2.75 0.70 0.70 0.12 0.16 Area to Apply 15 15 ha

Med Dogs 5.50 1.40 1.40 0.16 0.08 Number of Lots 225 525

Lge Dogs 8.25 2.10 2.10 0.19 0.00 Number of Dogs 106 126 Disposing in POS 6 15

Waste Disposal POS bags per year 1,390 3,311

Cost Data Cost of bags per year $118

R15 R35 Cost of mailout per year $375

Lot 35% 0% Distribution $1.00 per house Total PV Cost $8,209

POS 6% 12% Frequency 2 years Removal 17.2 kg/year

Bins 59% 88% Bag Costs $2.50 per 100 bags Cost per kg $29

Car Wash

Data Source Frequency based on JDA Survey (2001)TN/TP based on Polyglaze Autowash data via CRC for Freshwater Ecology (Canberra)Cost Estimate via JDA. Distribution cost and frequency is for brochure

Application Rates & Washing Frequency

Car wash detergent Washing Frequency Cost CalculationTN TP TN or TP (one car every x weeks) <=R20 >R20

kg/wash kg/wash specified R15 R35 Number of Lots 225 525 0.00009 0.00033 0.00033 2 4.5 Cost of mailout $375 per year

Total PV Cost $6,250Cost Data Distribution $1.00 per house Removal 0.8 kg/year

Frequency 2 years Cost per kg $477

Lot Fertiliser

Data Source Mean Fertiliser Applications via JDA survey (2001)% garden and lawns estimated via Aerial photography JDA(2001) for various suburbs with similar zoningsMinimum Fertiliser Applications via product recommended application data

Application RatesEducation Campaign

Fertiliser mean application TN or TP Fertiliser min application TN or TP Fertiliser Reduction TN or TP

kg TN/sqm/yr kg TP/sqm/yr specified kg TN/sqm/yr kg TP/sqm/yr specified kg TN/sqm/yr kg TP/sqm/yr specified % rednGarden 0.059 0.027 0.02700 Garden 0.010 0.003 0.00300 Garden 0.049 0.024 0.02400 89%Lawn 0.033 0.005 0.00500 Lawn 0.009 0.001 0.00100 Lawn 0.024 0.004 0.00400 80%

Garden and Lawn Areas Cost CalculationCost Data <=R20 >R20

R15 R35 Number of Lots 225 525 % garden 0.11 0.03 Distribution $1.00 per house Cost of mailout $375 per year% lawn 0.28 0.07 Frequency 2 years Total PV Cost $6,250

Removal 210.2 kg/yearCost per kg $2

POS Fertiliser

Data Source Application rates based on City of Armadale application toactive POS areas in year 1996-2000

Application Rates

Fertiliser mean application TN or TPkg TN/ha POS/yr kg TP/ha POS/yr specified

POS 73.4 2.6 2.60

Street Sweeping

Data Source Street Sweeping Revisited - Nutrients and Metals in Particle Size Fractions of Road Sedimentfrom two major roads in Perth (Davies & Pierce 1999), Water 99 Joint Congress BrisbaneCost based on Davies & Pierce (1998), $55/km

SAMPLE NiDSS INPUT ONLY

NiDSS Core Data & Cost CalculationsNutrient Input Decision Support SystemVersion 1.1 November 2001

Cost CalculationEstimated Removal Rate(assumes no WSUD upstream) reduction Cost $130 $/gross ha/yr

due to Cost Data Area to Apply 95 haPotential Reduction (kg/gross ha/yr) TN or TP upstream Total PV Cost $206,250

TN TP specified WSUD Cost $55.00 $/km Removal 26.0 kg/yearSweeping 0.75 0.35 0.35 26% Frequency 6 times per year Cost per kg $476

Note : Street sweeping applied to developed areas only - not existing rural land use areas not to be developed Costs apply to residential areas only

In-Transit Controls - Stormwater Nutrient Load

Data Source Nutrients in Perth Urban Surface Drainage Catchments Characterised by Applicable Attributes, Tan (1991)

Data Used to Calculate Nutrients in Stormwater Available for Removal by In-Transit ControlsRemoval quantities are for no WSUD and are reduced in calcs based on upstream measures used

Estimated Stormwater Nutrient Load(assumes no WSUD upstream)

TN or TPTypical Phosphorus Stormwater Load (Perth Urban Areas) 0.40 kg/gross ha/yr specifiedTypical Nitrogen Stormwater Load (Perth Urban Areas) 2.53 kg/gross ha/yr 0.40

Gross Pollutant Trap

Data Source Approximate average retention value via JDA(2001) - GeoTrap Laboratory Test ReportBased on GeoTrap, Humesceptor, Downstream Defender, CDSCost of GPT's via CRC report 98/3 (Allison, Chiew and McMahon) April 1998

Estimated Removal Rate Cost Data Cost Calculation

Percentage Removal TN or TP Capital Cost $1,880 per ha Area to Apply 95 haTN TP specified Maintenance $72 per ha/year Total PV Cost $292,600

GPT 35% 50% 50% Removal 14.5 kg/yearCost per kg $1,211

Note : GPT's applied to developed areas only - not existing rural land use areas not to be developed

Water Pollution Control Pond

Data Source TP removal efficiency and cost via Henley Brook Drive WPCP Conceptual Design (JDA,1997)TN efficiency via Managing Urban Stormwater Treatment Techniques (NSW EPA 1997)

Estimated Removal Rate Cost Data Cost Calculation

Percentage Removal TN or TP Capital Cost $1,800,000 Cost per kg $3,912 per kgTN TP specified Maintenance $25,000 per year Removal 14.3 kg/year

WPCP 35% 50% 50% Removal 34 kg TP/year Capital Cost $757,493Operating $10,521

Note : WPCP's applied to developed areas only - not existing rural land use areas not to be developed Total PV Cost $932,838

Town of Cambridge

Parks & Recreation Residential Nutrient Input (kg/gross ha/yr)

Passive Active Total R10 - R20 R20 - R60 Total Total NitrogenTotal

Phosphorus

CA 1 143.6 100.0% 0.0% 100% 0.0% 0.0% 0.0% 0 0

CA 2 48.3 19.2% 9.1% 28% 69.1% 2.6% 71.7% 122 29

CA 3 7.0 0.0% 49.6% 50% 11.7% 37.2% 48.9% 91 15

CA 4 36.1 11.6% 14.1% 26% 74.2% 0.0% 74.2% 133 31

CA 5 * 11.5 0.0% 12.5% 13% 87.5% 0.0% 87.5% 154 36

CA 6 98.6 22.5% 12.2% 35% 61.6% 3.2% 64.8% 114 26

CA 7 51.0 0.0% 83.4% 83% 16.6% 0.0% 16.6% 102 15

CA 8 * 3.0 0.0% 0.0% 0% 100.0% 0.0% 100.0% 161 39

CA 9 9.4 0.0% 100.0% 100% 0.0% 0.0% 0.0% 90 10

CA 10 33.8 0.0% 100.0% 100% 0.0% 0.0% 0.0% 90 10

CA 11 94.5 19.6% 8.1% 28% 69.9% 0.0% 69.9% 122 29

CA 12 4.4 0.0% 0.0% 0% 0.0% 26.8% 26.8% 47 8

CA 13 9.4 45.0% 5.0% 50% 0.0% 20.6% 20.6% 31 5

CA 14 49.2 52.3% 7.6% 60% 34.9% 0.0% 34.9% 66 15

CA 15 49.2 16.8% 39.9% 57% 43.3% 0.0% 43.3% 106 21

CA 16 30.3 0.0% 14.5% 15% 85.4% 0.0% 85.4% 152 36

CA 17 112.9 77.7% 4.1% 82% 18.2% 0.0% 18.2% 33 8

CA 18 32.9 84.6% 0.0% 85% 15.4% 0.0% 15.4% 25 6

CA 19 36.1 88.7% 0.0% 89% 11.3% 0.0% 11.3% 18 4

CA 20 7.8 2.3% 0.0% 2% 97.7% 0.0% 97.7% 159 39

CA 21 33.1 52.6% 31.1% 84% 0.0% 0.0% 0.0% 34 4

CA 22 5.8 95.3% 4.7% 100% 0.0% 0.0% 0.0% 4 0

CA 23 20.8 90.0% 1.6% 92% 8.4% 0.0% 8.4% 15 4

CA 24 * 94.9 97.2% 0.0% 97% 0.0% 0.0% 0.0% 1 0

CA 25 * 13.4 99.5% 0.5% 100% 0.0% 0.0% 0.0% 0 0

CA 26 * 18.1 20.3% 61.1% 81% 18.5% 0.0% 18.5% 85 14

CA 27 * 21.1 83.5% 2.2% 86% 11.9% 0.0% 11.9% 22 5

CA 28 * 429.1 47.1% 25.5% 73% 26.4% 0.0% 26.4% 66 13

CA 29 93.5 0.0% 55.1% 55% 44.9% 0.0% 44.9% 123 23

CA 30 * 5.2 0.0% 0.0% 0% 100.0% 0.0% 100.0% 161 39

CA 31 4.7 0.0% 0.0% 0% 100.0% 0.0% 100.0% 161 39

CA 32 21.8 0.0% 9.0% 9% 91.0% 0.0% 91.0% 156 37

CA 33 26.4 0.0% 58.0% 58% 41.6% 0.0% 41.6% 120 22

CA 34 83.4 0.0% 10.6% 11% 31.3% 48.3% 79.6% 99 21

CA 35 20.7 0.0% 21.7% 22% 19.6% 58.7% 78.3% 93 19

CA 36 25.5 0.0% 6.9% 7% 0.0% 63.2% 63.2% 63 12

CA 37 63.4 17.2% 12.0% 29% 0.0% 54.9% 54.9% 56 10

CA 38 * 12.6 56.6% 43.4% 100% 0.0% 0.0% 0.0% 39 4

CA - Lake Mo 67.9 100.0% 0.0% 100% 0.0% 0.0% 0.0% 0 0

ST 1 5.7 0.0% 35.3% 35% 58.1% 6.6% 64.7% 131 28

ST 2 12.6 0.0% 28.9% 29% 51.7% 9.3% 61.0% 121 26

ST 3 191.2 0.4% 8.8% 9% 89.9% 0.0% 89.9% 155 37

Sub Catchment

Area (ha)

Town of Claremont



Phosphorus

CL 1 * 21.7 0.0% 59.0% 59% 41.0% 0.0% 41% 120 22

CL 2 * 163.1 10.4% 45.1% 55% 24.3% 19.1% 43% 94 17

CL 3 18.4 0.0% 58.5% 59% 0.0% 40.0% 40% 82 12

CL 4 8.3 0.0% 2.4% 2% 0.0% 91.5% 91% 70 14

CL 5 3.5 0.0% 9.1% 9% 0.0% 90.9% 91% 73 15

CL 6 21.4 8.2% 91.1% 99% 0.0% 0.3% 0% 82 9

CL 7 * 1.7 0.0% 11.5% 11% 88.5% 0.0% 89% 154 36

CL 8 * 12.8 0.0% 20.1% 20% 79.9% 0.0% 80% 148 34

CL 9 8.3 0.0% 8.7% 9% 91.3% 0.0% 91% 156 37

CL 10 * 6.0 0.0% 1.8% 2% 98.2% 0.0% 98% 161 39

CL 11 * 1.4 0.0% 57.0% 57% 39.0% 3.9% 43% 118 22

CL 12 12.1 0.0% 2.2% 2% 97.8% 0.0% 98% 161 39

CL 13 1.7 0.0% 0.0% 0% 44.1% 0.0% 44% 93 21

CL 14 5.4 3.2% 38.2% 41% 57.8% 0.0% 58% 129 27

CL 15 * 12.7 1.6% 0.0% 2% 76.2% 19.7% 96% 137 33

CL 16 3.7 0.8% 0.0% 1% 0.0% 43.7% 44% 52 10

CL 17 2.2 20.5% 0.0% 21% 44.7% 15.5% 60% 90 21

CL 18 7.2 11.1% 17.2% 28% 71.7% 0.0% 72% 132 30

CL 19 * 25.4 0.0% 4.8% 5% 63.3% 4.7% 68% 121 28

CL 20 6.8 0.0% 0.0% 0% 98.8% 0.0% 99% 159 39

CL 21 * 128.1 0.0% 25.2% 25% 32.9% 29.2% 62% 102 21

CL 22 9.5 0.0% 0.0% 0% 65.5% 34.5% 100% 129 31

CL 23 11.0 0.0% 0.0% 0% 58.3% 41.7% 100% 122 29

CL 24 7.4 0.0% 29.0% 29% 11.8% 59.2% 71% 87 16

CL 25 * 18.5 0.0% 13.6% 14% 84.2% 2.2% 86% 151 35

CL - Railway R 16.6 95.1% 0.0% 95% 1.1% 1.1% 2% 4 1

Sub Catchment

Area (ha)

Town of Cottesloe


Passive Active Total R10 - R20 R20 - R60 Total Total

NitrogenTotal

Phosphorus

CO 1 4.7 99.4% 0.0% 99.4% 0.6% 0.0% 0.6% 1 0

CO 2 0.4 100.0% 0.0% 100.0% 0.0% 0.0% 0.0% 0 0

CO 3 11.8 1.1% 0.0% 1.1% 98.9% 0.0% 98.9% 159 39

CO 4 * 13.5 0.0% 5.7% 5.7% 88.8% 5.6% 94.3% 153 37

CO 5 * 17.7 0.0% 1.2% 1.2% 98.8% 0.0% 98.8% 162 40

CO 6 5.5 0.0% 0.0% 0.0% 95.9% 4.1% 100.0% 157 38

CO 7 7.8 50.3% 9.3% 59.6% 0.0% 40.4% 40.4% 37 7

CO 8 2.7 12.5% 53.6% 66.1% 12.7% 21.1% 33.9% 84 14

CO 9 1.1 0.0% 0.0% 0.0% 0.0% 100.0% 100.0% 68 14

CO 10 0.2 0.0% 0.0% 0.0% 0.0% 100.0% 100.0% 68 14

CO 11 1.7 0.0% 0.0% 0.0% 95.6% 4.4% 100.0% 157 38

CO 12 3.3 0.0% 0.0% 0.0% 30.9% 69.1% 100.0% 97 22

CO 13 20.4 0.0% 0.0% 0.0% 99.9% 0.0% 99.9% 161 39

CO 14 4.1 7.1% 0.0% 7.1% 92.9% 0.0% 92.9% 149 37

CO 15 * 0.4 47.8% 0.0% 47.8% 52.2% 0.0% 52.2% 84 21

CO 16 3.8 5.3% 14.4% 19.7% 47.0% 33.3% 80.3% 113 25

CO 17 13.7 6.3% 12.7% 19.0% 78.5% 0.8% 79.2% 140 33

CO 18 1.2 0.0% 42.9% 42.9% 54.1% 2.6% 56.8% 129 26

CO 19 13.7 0.0% 10.6% 10.6% 65.2% 24.1% 89.4% 133 31

CO 20 11.0 50.9% 0.0% 50.9% 1.0% 23.0% 23.9% 27 5

CO 21 3.9 13.0% 0.0% 13.0% 0.0% 36.6% 36.6% 45 8

CO 22 4.0 0.0% 1.9% 1.9% 0.0% 4.2% 4.2% 42 6

CO 23 1.4 0.0% 0.0% 0.0% 3.8% 41.0% 44.7% 56 11

CO 24 11.0 0.0% 19.3% 19.3% 49.9% 18.7% 68.6% 117 25

CO 25 3.0 0.0% 0.7% 0.7% 99.3% 0.0% 99.3% 162 40

CO 26 22.8 1.8% 0.0% 1.8% 90.3% 2.5% 92.7% 149 36

CO 27 0.8 6.5% 0.0% 6.5% 93.5% 0.0% 93.5% 150 37

CO 28 6.7 5.7% 0.6% 6.3% 89.3% 1.0% 90.3% 148 36

CO 29 1.9 0.0% 0.0% 0.0% 71.0% 29.0% 100.0% 134 32

CO 30 0.3 3.0% 0.0% 3.0% 97.0% 0.0% 97.0% 156 38

CO 31 4.2 100.0% 0.0% 100.0% 0.0% 0.0% 0.0% 0 0

CO 32 35.1 2.1% 73.0% 75.1% 15.7% 4.5% 20.2% 96 15

CO 33 3.6 1.7% 0.0% 1.7% 98.3% 0.0% 98.3% 158 39

CO 34 6.6 0.0% 0.9% 0.9% 99.1% 0.0% 99.1% 162 40

CO 35 9.9 4.5% 1.7% 6.2% 93.8% 0.0% 93.8% 154 38

CO 36 10.7 4.1% 0.0% 4.1% 47.7% 47.6% 95.3% 109 26

CO 37 7.1 7.3% 0.0% 7.3% 0.0% 92.7% 92.7% 63 13

CO 38 20.6 24.9% 2.8% 27.7% 0.0% 72.3% 72.3% 54 11

CO 39 21.9 2.8% 0.2% 3.0% 84.0% 13.0% 97.0% 146 35

CO 40 16.5 23.9% 0.0% 23.9% 0.0% 55.5% 55.5% 46 9

CO 41 0.3 0.0% 0.0% 0.0% 0.0% 0.4% 0.4% 40 6

CO 42 0.1 0.0% 0.0% 0.0% 0.0% 57.7% 57.7% 56 11

CO 43 4.3 6.0% 0.0% 6.0% 10.7% 46.3% 57.0% 63 13

CO 44 10.1 34.1% 0.0% 34.1% 0.0% 59.3% 59.3% 43 9

CO 45 0.3 75.9% 0.0% 75.9% 0.0% 24.1% 24.1% 16 3

CO 46 3.2 99.6% 0.0% 99.6% 0.0% 0.4% 0.4% 0 0

CO - Railway 28.8 99.9% 0.0% 99.9% 0.0% 0.1% 0.1% 0 0

Sub Catchment

Area (ha)

Town of Mosman Park



Phosphorus

MP 1 25.4 3.1% 0.0% 3% 4.8% 77.9% 82.7% 66 14

MP 2 24.8 0.0% 23.7% 24% 73.2% 2.5% 75.7% 142 32

MP 3 * 18.4 0.0% 48.3% 48% 39.0% 12.7% 51.7% 116 22

MP 4 0.8 0.0% 95.0% 95% 0.0% 5.0% 5.0% 89 10

MP 5 1.5 0.0% 100.0% 100% 0.0% 0.0% 0.0% 90 10

MP 6 22.3 0.0% 25.1% 25% 61.4% 2.8% 64.2% 129 28

MP 7 1.4 0.0% 100.0% 100% 0.0% 0.0% 0.0% 90 10

MP 8 60.3 0.1% 27.4% 27% 28.4% 41.7% 70.1% 101 20

MP 9 46.9 0.0% 5.2% 5% 92.4% 0.0% 92.4% 156 38

MP 10 2.4 0.0% 74.4% 74% 25.6% 0.0% 25.6% 109 18

MP 11 1.0 0.0% 58.7% 59% 41.3% 0.0% 41.3% 120 22

MP 12 1.8 0.0% 11.0% 11% 89.0% 0.0% 89.0% 155 37

MP 13 6.3 0.0% 5.9% 6% 94.1% 0.0% 94.1% 158 38

MP 14 1.0 0.0% 20.2% 20% 79.8% 0.0% 79.8% 148 34

MP 15 2.8 0.0% 3.2% 3% 96.8% 0.0% 96.8% 160 39

MP 16 1.0 0.0% 15.5% 16% 84.5% 0.0% 84.5% 151 35

MP 17 1.7 0.0% 9.6% 10% 90.4% 0.0% 90.4% 156 37

MP 18 2.4 100.0% 0.0% 100% 0.0% 0.0% 0.0% 0 0

MP 19 3.8 99.9% 0.1% 100% 0.0% 0.0% 0.0% 0 0

MP 20 1.1 0.1% 99.9% 100% 0.0% 0.0% 0.0% 90 10

MP 21 6.0 0.0% 100.0% 100% 0.0% 0.0% 0.0% 90 10

MP 22 13.2 0.0% 26.4% 26% 62.0% 3.5% 65.5% 130 28

MP 23 9.7 0.0% 19.0% 19% 7.5% 58.9% 66.4% 77 15

MP 24 21.2 0.0% 15.6% 16% 71.6% 4.1% 75.8% 137 31

MP 25 1.8 0.0% 100.0% 100% 0.0% 0.0% 0.0% 90 10

MP 26 20.6 0.0% 14.7% 15% 77.3% 7.9% 85.3% 145 34

MP 27 28.3 0.0% 93.3% 93% 6.7% 0.0% 6.7% 95 12

MP 28 3.4 0.0% 90.7% 91% 9.3% 0.0% 9.3% 97 13

MP 29 0.6 0.0% 100.0% 100% 0.0% 0.0% 0.0% 90 10

MP 30 5.7 0.0% 44.3% 44% 55.7% 0.0% 55.7% 130 27

MP 31 2.1 0.0% 67.4% 67% 32.6% 0.0% 32.6% 114 20

MP 32 2.2 0.0% 97.9% 98% 2.1% 0.0% 2.1% 92 11

MP 33 10.4 0.0% 19.6% 20% 80.0% 0.4% 80.4% 148 34

MP 34 15.7 0.0% 34.1% 34% 0.0% 65.9% 65.9% 78 13

MP 35 8.3 0.0% 72.8% 73% 27.2% 0.0% 27.2% 110 18

MP 36 8.2 0.0% 100.0% 100% 0.0% 0.0% 0.0% 90 10

MP 37 0.5 0.0% 1.2% 1% 98.8% 0.0% 98.8% 162 40

MP 38 5.2 0.0% 65.9% 66% 34.1% 0.0% 34.1% 115 20

MP 39 13.6 0.0% 48.8% 49% 51.2% 0.0% 51.2% 127 25

MP - Railway 9.9 100.0% 0.0% 100% 0.0% 0.0% 0.0% 0 0

FR 1 4.9 0.0% 16.1% 16% 0.0% 83.9% 83.9% 74 14

Sub Catchment

Area (ha)

City of Nedlands


Passive Active Total R10 - R20 R20 - R60 TotalTotal

NitrogenTotal

Phosphorus

NE 1 192.3 99.8% 0.2% 100.0% 0.0% 0.0% 0.0% 0 0

NE 2 13.8 52.0% 17.0% 68.9% 31.1% 0.0% 31.1% 66 14

NE 3 0.9 58.4% 0.0% 58.4% 41.6% 0.0% 41.6% 67 16

NE 4 25.5 12.8% 33.1% 45.9% 54.1% 0.0% 54.1% 118 25

NE 5 * 57.6 51.0% 48.9% 99.8% 0.2% 0.0% 0.2% 44 5

NE 6 6.0 43.2% 25.9% 69.2% 30.0% 0.8% 30.8% 73 15

NE 7 1.6 70.2% 24.7% 94.9% 0.0% 5.1% 5.1% 26 3

NE 8 15.2 0.0% 27.4% 27.4% 63.7% 8.9% 72.6% 135 30

NE 9 * 4.8 0.0% 6.5% 6.5% 71.2% 22.3% 93.5% 138 32

NE 10 * 38.9 0.0% 28.8% 28.8% 48.1% 23.0% 71.2% 121 26

NE 11 * 13.3 0.0% 81.6% 81.6% 18.4% 0.0% 18.4% 103 16

NE 12 24.7 0.0% 96.1% 96.1% 3.9% 0.0% 3.9% 93 11

NE 13 * 16.0 0.0% 0.2% 0.2% 86.8% 5.3% 92.1% 148 36

NE 14 26.7 0.0% 6.5% 6.5% 93.5% 0.0% 93.5% 158 38

NE 15 * 19.5 0.0% 12.0% 12.0% 77.1% 10.9% 88.0% 144 34

NE 16 15.0 0.0% 79.3% 79.3% 20.7% 0.0% 20.7% 105 16

NE 17 33.0 0.0% 95.8% 95.8% 0.0% 0.0% 0.0% 88 10

NE 18 * 50.4 0.2% 7.7% 7.9% 78.6% 13.3% 91.9% 144 34

NE 19 37.3 0.0% 38.5% 38.5% 14.8% 15.5% 30.4% 82 14

NE 20 12.8 0.0% 0.1% 0.1% 0.0% 29.0% 29.0% 49 9

NE 21 19.8 0.0% 1.5% 1.5% 1.6% 45.1% 46.7% 57 11

NE 22 * 2.6 0.0% 0.4% 0.4% 0.0% 99.6% 99.6% 71 15

NE 23 14.0 0.0% 48.3% 48.3% 51.7% 0.0% 51.7% 128 25

NE 24 147.4 0.0% 25.4% 25.4% 0.0% 43.4% 43.4% 66 11

NE 25 * 27.4 0.0% 5.7% 5.7% 0.0% 79.0% 79.0% 67 13

NE 26 * 22.7 7.2% 61.3% 68.5% 27.8% 0.0% 27.8% 102 17

NE 27 90.3 0.1% 58.0% 58.1% 32.7% 3.0% 35.7% 110 20

NE 28 * 10.7 8.7% 85.1% 93.8% 6.2% 0.0% 6.2% 87 11

NE 29 24.8 0.0% 100.0% 100.0% 0.0% 0.0% 0.0% 90 10

NE 30 * 140.4 0.3% 15.6% 15.9% 28.7% 14.8% 43.5% 87 18

NE 31 10.6 0.0% 48.4% 48.4% 42.9% 8.7% 51.6% 119 23

NE 32 * 13.4 0.0% 1.4% 1.4% 98.6% 0.0% 98.6% 162 40

NE 33 5.9 0.0% 4.7% 4.7% 90.5% 0.0% 90.5% 153 37

NE 34 6.0 0.0% 0.0% 0.0% 44.6% 20.1% 64.8% 99 23

NE 35 6.1 0.0% 0.0% 0.0% 34.1% 23.7% 57.8% 89 20

NE 36 * 67.5 0.0% 10.4% 10.4% 79.1% 5.2% 84.3% 144 34

NE 37 35.0 0.0% 0.2% 0.2% 73.7% 12.8% 86.5% 134 32

NE 38 34.2 0.0% 4.2% 4.2% 95.8% 0.0% 95.8% 160 39

NE 39 * 104.1 0.0% 15.2% 15.2% 84.8% 0.0% 84.8% 152 35

NE 40 0.5 0.0% 7.0% 7.0% 93.0% 0.0% 93.0% 158 38

NE 41 5.8 0.0% 2.5% 2.5% 97.5% 0.0% 97.5% 161 39

NE 42 * 18.3 0.0% 0.0% 0.0% 100.0% 0.0% 100.0% 161 39

NE 43 1.8 0.0% 2.4% 2.4% 97.6% 0.0% 97.6% 161 39

NE 44 6.3 0.0% 20.3% 20.3% 79.7% 0.0% 79.7% 148 34

NE 45 58.2 0.0% 33.3% 33.3% 66.7% 0.0% 66.7% 138 30

NE 46 6.9 0.0% 0.0% 0.0% 100.0% 0.0% 100.0% 161 39

NE 47 3.2 0.0% 3.7% 3.7% 96.3% 0.0% 96.3% 160 39

NE 48 2.8 0.0% 7.1% 7.1% 92.9% 0.0% 92.9% 157 38

NE 49 3.2 0.0% 36.0% 36.0% 64.0% 0.0% 64.0% 136 29

NE 50 51.0 0.0% 9.9% 9.9% 90.1% 0.0% 90.1% 155 37

NE 51 32.4 0.0% 58.0% 58.0% 42.0% 0.0% 42.0% 120 23

NE 52 39.5 0.0% 34.5% 34.5% 65.5% 0.0% 65.5% 138 30

NE 53 51.8 0.0% 45.6% 45.6% 52.5% 0.0% 52.5% 127 26

NE - Railway 16.0 84.4% 0.0% 84.4% 0.0% 8.9% 8.9% 9 2

Sub Catchment

Area (ha)

Shire of Peppermint Grove



NitrogenTotal

Phosphorus

PG 1 43.2 0.0% 9.2% 9.2% 71.8% 9.7% 81.5% 136 32

PG 2 * 43.8 0.0% 25.9% 25.9% 74.1% 0.0% 74.1% 144 32

PG 3 2.1 5.6% 53.1% 58.7% 36.4% 2.7% 39.2% 110 20

PG 4 * 13.2 2.1% 15.8% 17.9% 58.0% 8.2% 66.2% 121 27

PG 5 * 14.1 0.0% 6.4% 6.4% 93.2% 0.0% 93.2% 157 38

PG - Railway 0.8 99.1% 0.1% 99.2% 0.0% 0.8% 0.8% 1 0

Sub Catchment

Area (ha)

City of Subiaco



NitrogenTotal

Phosphorus

SU 1 * 243.8 0.3% 17.1% 17.5% 56.6% 14.5% 71.1% 122 27

SU 2 * 50.4 0.1% 7.4% 7.5% 6.4% 34.3% 40.7% 62 12

SU 3 * 241.6 0.3% 18.2% 18.5% 42.2% 23.6% 65.8% 108 23

SU 4 * 85.9 0.0% 17.2% 17.2% 19.0% 2.2% 21.2% 72 13

SU 5 151.4 1.7% 8.6% 10.3% 86.0% 0.8% 86.8% 149 35

SU 6 * 113.4 11.2% 0.5% 11.7% 50.1% 31.3% 81.4% 107 25

SU 7 * 88.5 0.2% 10.0% 10.2% 50.6% 32.3% 82.9% 117 26

SU 8 19.3 0.0% 100.0% 100.0% 0.0% 0.0% 0.0% 90 10

SU 9 21.1 23.1% 68.0% 91.0% 0.0% 8.8% 8.8% 68 8

SU 10 21.3 0.0% 100.0% 100.0% 0.0% 0.0% 0.0% 90 10

SU - Railway 12.2 99.9% 0.0% 99.9% 0.0% 0.1% 0.1% 0 0

Sub Catchment

Area (ha)

APPENDIX 4

Priority Sub Catchment Calculations

Priority Rating SystemDetermination of Priority Subcatchments JDA Consultant Hydrologists

Discharge Rating System

Overall Priority Weighting System Applied (%) Infiltration Basin / Swale 1

OUT : Discharge Type 50.0% Soakwell 1

IN : Nutrient Input (kg/ha/yr) 12.5% Railway Reserves 2

IN : Major Roads (km/ha) 12.5% Parks / Reserves 2

IN : Ind/Comm Areas (% of catch) 12.5% Lake 3

IN : Contamination Sites (No.) 12.5% Ocean / Dunes via Comp Basin 3

Total ( sum to 100%) 100% River via Comp Basin 3

Note : The lower the percentage, the less the significance Ocean / Dunes 4

River 4

Unknown 1

Other Assessment Parameter Rating Systems

Assessment Parameter Rating 1 Low Rating 2 Low Rating 3 Low Rating 4 Low Rating 5 Low Rating 6 Low Rating 7 Low Rating 8 Low Rating 9 Low

Nutrient Input (kg/ha/yr) 0 1 10 20 30

Major Roads (km/ha) 0.000 0.001 0.010 0.025 0.050

Industrial Areas (% of catch) 0.0% 0.1% 10.0% 30.0% 50.0%

Contamination Sites (No.) 0 1 2 3 4

Assessment Value 0 1 2 3 4

Town of CambridgeDetermination of Priority Subcatchments JDA Consultant Hydrologists

Total Catchments = 41

No of Catchments receiving flow from outside LA area = 8 (denoted by asterisk)

No of Catchments in other LA areas to which Cambridge contributes = 11

Nutrient Input Major Roads Ind/Comm Areas Contamination Sites

Parks & Recreation (kg/gross ha/yr) qualitative analysis qualitative analysis qualitative analysis

Passive Active R10-R20 R25-R60Industrial

CommercialTN TP

Length of Road (km)

Density (km/ha)

Industrial Area (ha)

% of total catchment

Potential GW Contamination

Sites

Fuel Storage

Remediated

CA 1 143.6 100.0% 0.0% 0.0% 0.0% 0.0% Ocean / Dunes No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.00 10

CA 2 48.3 19.2% 9.1% 69.1% 2.6% 0.0% Infiltration Basin / Swale No 1 122 29 3 1.52 0.032 3 0.0 0.0% 0 0 0 0 0 1.25 22



CA 5 * 11.5 0.0% 12.5% 87.5% 0.0% 0.0% Infiltration Basin / Swale No 1 154 36 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 33

CA 6 98.6 22.5% 12.2% 61.6% 3.2% 0.4% Parks / Reserves No 2 114 26 3 2.36 0.024 2 0.4 0.4% 1 0 0 0 0 1.75 12



















CA 25 * 13.4 99.5% 0.5% 0.0% 0.0% 0.0% Parks / Reserves No 2 0 0 0 0.15 0.011 2 0.0 0.0% 0 0 0 0 0 1.25 22



CA 28 * 429.1 47.1% 25.5% 26.4% 0.0% 1.0% Ocean / Dunes via Comp Basin Yes 4 66 13 2 6.44 0.015 2 4.4 1.0% 1 1 2 2 1 2.75 3




CA 32 21.8 0.0% 9.0% 91.0% 0.0% 0.0% Ocean / Dunes via Comp Basin No 3 156 37 4 0.32 0.015 2 0.0 0.0% 0 0 0 0 0 2.25 9

CA 33 26.4 0.0% 58.0% 41.6% 0.0% 0.5% River via Comp Basin Yes 4 120 22 3 0.37 0.014 2 0.1 0.5% 1 0 0 0 0 2.75 3




CA 37 63.4 17.2% 12.0% 0.0% 54.9% 15.9% River No 4 56 10 2 3.99 0.063 4 10.1 15.9% 2 0 0 0 0 3.00 2

RankRating

Catchments

Total Score

Discharge Type

Conserv Category Wetland

Land Use

Rating Rating RatingRatingSub Catchment

Area (ha)

Receving Environment

Residential

Town of ClaremontDetermination of Priority Subcatchments JDA Consultant Hydrologists



No of Catchments in other LA areas to which Claremont contributes = 9




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

CL 1 * 21.7 0.0% 59.0% 41.0% 0.0% 0.0% Infiltration Basin / Swale No 1 120 22 3 0.28 0.013 2 0.0 0.0% 0 0 0 0 0 1.13 15

CL 2 * 163.1 10.4% 45.1% 24.3% 19.1% 1.1% Lake Yes 4 94 17 2 1.21 0.007 1 1.8 1.1% 1 2 1 0 3 2.88 2

CL 3 18.4 0.0% 58.5% 0.0% 40.0% 1.5% Infiltration Basin / Swale No 1 82 12 2 0.18 0.010 2 0.3 1.5% 1 0 0 0 0 1.13 15




CL 7 * 1.7 0.0% 11.5% 88.5% 0.0% 0.0% Soakwell No 1 154 36 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 19



CL 10 * 6.0 0.0% 1.8% 98.2% 0.0% 0.0% Soakwell No 1 161 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 19




CL 14 5.4 3.2% 38.2% 57.8% 0.0% 0.9% Soakwell No 1 129 27 3 0.00 0.000 0 0.0 0.9% 1 0 0 0 0 1.00 19




CL 18 7.2 11.1% 17.2% 71.7% 0.0% 0.0% Soakwell No 1 132 30 4 0.58 0.080 4 0.0 0.0% 0 0 0 0 0 1.50 8



CL 21 * 128.1 0.0% 25.2% 32.9% 29.2% 12.7% River No 4 102 21 3 3.79 0.030 3 16.2 12.7% 2 0 1 0 1 3.13 1


CL 23 11.0 0.0% 0.0% 58.3% 41.7% 0.0% Soakwell No 1 122 29 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.88 24

CL 24 7.4 0.0% 29.0% 11.8% 59.2% 0.0% River No 4 87 16 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 4

CL 25 * 18.5 0.0% 13.6% 84.2% 2.2% 0.0% River No 4 151 35 4 0.12 0.007 1 0.0 0.0% 0 0 0 0 0 2.63 3

CL - Railway R 16.6 95.1% 0.0% 1.1% 1.1% 2.7% Railway Reserves No 2 4 1 0 2.33 0.141 4 0.4 2.7% 1 1 0 1 0 1.63 5

RankRating

Catchments

Total Score

Discharge Type


Land Use


Area (ha)


Residential

Town of CottesloeDetermination of Priority Subcatchments JDA Consultant Hydrologists



No of Catchments in other LA areas to which Cottesloe contributes = 3




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

CO 1 4.7 99.4% 0.0% 0.6% 0.0% 0.0% Ocean / Dunes No 4 1 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.00 8

CO 2 0.4 100.0% 0.0% 0.0% 0.0% 0.0% Infiltration Basin / Swale No 1 0 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.50 47


CO 4 * 13.5 0.0% 5.7% 88.8% 5.6% 0.0% Infiltration Basin / Swale No 1 153 37 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 32



CO 7 7.8 50.3% 9.3% 0.0% 40.4% 0.0% Ocean / Dunes No 4 37 7 1 0.02 0.003 1 0.0 0.0% 0 0 0 0 0 2.25 5









CO 16 3.8 5.3% 14.4% 47.0% 33.3% 0.0% Railway Reserves No 2 113 25 3 0.66 0.172 4 0.0 0.0% 0 1 0 1 0 1.88 11




CO 20 11.0 50.9% 0.0% 1.0% 23.0% 25.2% Ocean / Dunes No 4 27 5 1 0.00 0.000 0 2.8 25.2% 2 0 1 1 0 2.38 3



CO 23 1.4 0.0% 0.0% 3.8% 41.0% 55.3% Soakwell No 1 56 11 2 0.00 0.000 0 0.8 55.3% 4 0 0 0 0 1.25 25






CO 29 1.9 0.0% 0.0% 71.0% 29.0% 0.0% Soakwell No 1 134 32 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 32

CO 30 0.3 3.0% 0.0% 97.0% 0.0% 0.0% Soakwell No 1 156 38 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 32

CO 31 4.2 100.0% 0.0% 0.0% 0.0% 0.0% Ocean / Dunes No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.00 8







CO 38 20.6 24.9% 2.8% 0.0% 72.3% 0.0% Ocean / Dunes No 4 54 11 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 5


CO 40 16.5 23.9% 0.0% 0.0% 55.5% 20.5% Ocean / Dunes No 4 46 9 1 0.00 0.000 0 3.4 20.5% 2 0 0 0 0 2.38 3



RankRating

Catchments

Total Score

Discharge Type


Land Use


Area (ha)


Residential

Town of CottesloeDetermination of Priority Subcatchments JDA Consultant Hydrologists



No of Catchments in other LA areas to which Cottesloe contributes = 3




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

RankRating

Catchments

Total Score

Discharge Type


Land Use


Area (ha)


Residential


CO 44 10.1 34.1% 0.0% 0.0% 59.3% 6.5% Ocean / Dunes No 4 43 9 1 0.14 0.014 2 0.7 6.5% 1 0 0 0 0 2.50 1


CO 46 3.2 99.6% 0.0% 0.0% 0.4% 0.0% Ocean / Dunes No 4 0 0 0 0.33 0.105 4 0.0 0.0% 0 0 0 0 0 2.50 1

CO - Railway R 28.8 99.9% 0.0% 0.0% 0.1% 0.0% Railway Reserves No 2 0 0 0 0.10 0.003 1 0.0 0.0% 0 0 0 0 0 1.13 27

Town of Mosman ParkDetermination of Priority Subcatchments JDA Consultant Hydrologists



No of Catchments in other LA areas to which Mosman Park contributes = 4




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

MP 1 25.4 3.1% 0.0% 4.8% 77.9% 14.3% Infiltration Basin / Swale No 1 66 14 2 0.87 0.034 3 3.6 14.3% 2 0 0 0 0 1.38 23


MP 3 * 18.4 0.0% 48.3% 39.0% 12.7% 0.0% River No 4 116 22 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 7

MP 4 0.8 0.0% 95.0% 0.0% 5.0% 0.0% River No 4 89 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10

MP 5 1.5 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10


MP 7 1.4 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10



MP 10 2.4 0.0% 74.4% 25.6% 0.0% 0.0% River No 4 109 18 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10

MP 11 1.0 0.0% 58.7% 41.3% 0.0% 0.0% River No 4 120 22 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 7

MP 12 1.8 0.0% 11.0% 89.0% 0.0% 0.0% River No 4 155 37 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 1

MP 13 6.3 0.0% 5.9% 94.1% 0.0% 0.0% River No 4 158 38 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 1

MP 14 1.0 0.0% 20.2% 79.8% 0.0% 0.0% River No 4 148 34 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 1

MP 15 2.8 0.0% 3.2% 96.8% 0.0% 0.0% River No 4 160 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 1

MP 16 1.0 0.0% 15.5% 84.5% 0.0% 0.0% River No 4 151 35 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 1

MP 17 1.7 0.0% 9.6% 90.4% 0.0% 0.0% River No 4 156 37 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 1

MP 18 2.4 100.0% 0.0% 0.0% 0.0% 0.0% Ocean / Dunes No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 2 0 0 2 2.25 10

MP 19 3.8 99.9% 0.1% 0.0% 0.0% 0.0% Soakwell No 1 0 0 0 0.62 0.164 4 0.0 0.0% 0 0 0 0 0 1.00 33

MP 20 1.1 0.1% 99.9% 0.0% 0.0% 0.0% Railway Reserves No 2 90 10 1 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.13 28

MP 21 6.0 0.0% 100.0% 0.0% 0.0% 0.0% Parks / Reserves No 2 90 10 2 0.29 0.048 3 0.0 0.0% 0 0 0 0 0 1.63 22







MP 28 3.4 0.0% 90.7% 9.3% 0.0% 0.0% River No 4 97 13 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10

MP 29 0.6 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10

MP 30 5.7 0.0% 44.3% 55.7% 0.0% 0.0% River No 4 130 27 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 7

MP 31 2.1 0.0% 67.4% 32.6% 0.0% 0.0% River No 4 114 20 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10

MP 32 2.2 0.0% 97.9% 2.1% 0.0% 0.0% River No 4 92 11 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10


MP 34 15.7 0.0% 34.1% 0.0% 65.9% 0.0% River No 4 78 13 2 0.00 0.000 0 0.0 0.0% 0 1 0 1 0 2.25 10



MP 37 0.5 0.0% 1.2% 98.8% 0.0% 0.0% Soakwell No 1 162 40 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 33

MP 38 5.2 0.0% 65.9% 34.1% 0.0% 0.0% Soakwell No 1 115 20 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.88 38

MP 39 13.6 0.0% 48.8% 51.2% 0.0% 0.0% Soakwell No 1 127 25 3 0.00 0.000 0 0.0 0.0% 0 1 0 0 1 1.00 33

MP - Railway R 9.9 100.0% 0.0% 0.0% 0.0% 0.0% Railway Reserves No 2 0 0 0 0.60 0.060 4 0.0 0.0% 0 2 0 0 2 1.75 21

FR 1 4.9 0.0% 16.1% 0.0% 83.9% 0.0% River No 4 74 14 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 10

RankRating

Catchments

Total Score

Discharge Type


Land Use


Area (ha)


Residential

City of NedlandsDetermination of Priority Subcatchments JDA Consultant Hydrologists



No of Catchments in other LA areas to which Nedlands contributes = 19




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

NE 1 192.3 99.8% 0.2% 0.0% 0.0% 0.0% Ocean / Dunes No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 2 0 0 2 2.25 13

NE 2 13.8 52.0% 17.0% 31.1% 0.0% 0.0% Ocean / Dunes No 4 66 14 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 13

NE 3 0.9 58.4% 0.0% 41.6% 0.0% 0.0% Ocean / Dunes No 4 67 16 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 13

NE 4 25.5 12.8% 33.1% 54.1% 0.0% 0.0% Infiltration Basin / Swale No 1 118 25 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.88 49

NE 5 * 57.6 51.0% 48.9% 0.2% 0.0% 0.0% Parks / Reserves No 2 44 5 1 1.58 0.027 3 0.0 0.0% 0 0 0 0 0 1.50 21




NE 9 * 4.8 0.0% 6.5% 71.2% 22.3% 0.0% Infiltration Basin / Swale No 1 138 32 4 0.93 0.193 4 0.0 0.0% 0 0 0 0 0 1.50 21



NE 12 24.7 0.0% 96.1% 3.9% 0.0% 0.0% Parks / Reserves No 2 93 11 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.25 33



NE 15 * 19.5 0.0% 12.0% 77.1% 10.9% 0.0% Soakwell No 1 144 34 4 0.94 0.048 3 0.0 0.0% 0 0 0 0 0 1.38 27








NE 23 14.0 0.0% 48.3% 51.7% 0.0% 0.0% Soakwell No 1 128 25 3 0.19 0.014 2 0.0 0.0% 0 0 0 0 0 1.13 41






NE 29 24.8 0.0% 100.0% 0.0% 0.0% 0.0% Soakwell No 1 90 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.75 51

NE 30 * 140.4 0.3% 15.6% 28.7% 14.8% 40.6% Ocean / Dunes via Comp Basin No 3 87 18 2 4.49 0.032 3 57.0 40.6% 3 1 0 0 1 2.63 1

NE 31 10.6 0.0% 48.4% 42.9% 8.7% 0.0% Soakwell No 1 119 23 3 0.27 0.026 3 0.0 0.0% 0 0 0 0 0 1.25 33









NE 40 0.5 0.0% 7.0% 93.0% 0.0% 0.0% River No 4 158 38 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 4

NE 41 5.8 0.0% 2.5% 97.5% 0.0% 0.0% River No 4 161 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 4

NE 42 * 18.3 0.0% 0.0% 100.0% 0.0% 0.0% Soakwell No 1 161 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 46

RankRating

Catchments

Total Score

Discharge Type


Land Use


Area (ha)


Residential

City of NedlandsDetermination of Priority Subcatchments JDA Consultant Hydrologists



No of Catchments in other LA areas to which Nedlands contributes = 19




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

RankRating

Catchments

Total Score

Discharge Type


Land Use


Area (ha)


Residential

NE 43 1.8 0.0% 2.4% 97.6% 0.0% 0.0% River No 4 161 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 4

NE 44 6.3 0.0% 20.3% 79.7% 0.0% 0.0% River No 4 148 34 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 4

NE 45 58.2 0.0% 33.3% 66.7% 0.0% 0.0% River No 4 138 30 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 10


NE 47 3.2 0.0% 3.7% 96.3% 0.0% 0.0% River No 4 160 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 4

NE 48 2.8 0.0% 7.1% 92.9% 0.0% 0.0% River No 4 157 38 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 4

NE 49 3.2 0.0% 36.0% 64.0% 0.0% 0.0% River No 4 136 29 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 10


NE 51 32.4 0.0% 58.0% 42.0% 0.0% 0.0% River No 4 120 23 3 0.00 0.000 0 0.0 0.0% 0 2 0 0 2 2.63 1

NE 52 39.5 0.0% 34.5% 65.5% 0.0% 0.0% River No 4 138 30 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 10

NE 53 51.8 0.0% 45.6% 52.5% 0.0% 1.8% River No 4 127 26 3 0.00 0.000 0 1.0 1.8% 1 1 0 0 1 2.63 1

Shire of Peppermint GroveDetermination of Priority Subcatchments JDA Consultant Hydrologists



No of Catchments in other LA areas to which Peppermint Grove contributes = 2




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

PG 1 43.2 0.0% 9.2% 71.8% 9.7% 9.3% Infiltration Basin / Swale No 1 136 32 4 1.05 0.024 2 4.0 9.3% 1 0 0 0 0 1.38 4

PG 2 * 43.8 0.0% 25.9% 74.1% 0.0% 0.0% River No 4 144 32 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 1


PG 4 * 13.2 2.1% 15.8% 58.0% 8.2% 15.9% Infiltration Basin / Swale No 1 121 27 3 0.43 0.033 3 2.1 15.9% 2 0 1 0 1 1.63 2


PG - Railwa 0.8 99.1% 0.1% 0.0% 0.8% 0.0% Railway Reserves No 2 1 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 6

RatingSub Catchment

Area (ha)


ResidentialRankRating

Catchments

Total Score

Discharge Type


Land Use

Rating Rating Rating

City of SubiacoDetermination of Priority Subcatchments JDA Consultant Hydrologists



No of Catchments in other LA areas to which Subiaco contributes = 2




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

SU 1 * 243.8 0.3% 17.1% 56.6% 14.5% 11.5% River via Comp Basin Yes 4 122 27 3 7.83 0.032 3 28.0 11.5% 2 3 6 2 4 3.50 1


SU 3 * 241.6 0.3% 18.2% 42.2% 23.6% 15.7% Ocean / Dunes via Comp Basin No 3 108 23 3 10.03 0.041 3 38.0 15.7% 2 4 2 0 4 3.00 3


SU 5 151.4 1.7% 8.6% 86.0% 0.8% 2.9% Ocean / Dunes via Comp Basin No 3 149 35 4 3.52 0.023 2 4.5 2.9% 1 1 2 0 3 2.75 6

SU 6 * 113.4 11.2% 0.5% 50.1% 31.3% 6.9% River No 4 107 25 3 3.02 0.027 3 7.8 6.9% 1 0 1 0 1 3.00 3

SU 7 * 88.5 0.2% 10.0% 50.6% 32.3% 6.9% River No 4 117 26 3 1.77 0.020 2 6.1 6.9% 1 1 0 0 1 2.88 5

SU 8 19.3 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.20 0.011 2 0.0 0.0% 0 0 0 0 0 2.50 8

SU 9 21.1 23.1% 68.0% 0.0% 8.8% 0.1% River No 4 68 8 1 0.00 0.000 0 0.0 0.1% 1 0 0 0 0 2.25 10

SU 10 21.3 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.89 0.042 3 0.0 0.0% 0 0 0 0 0 2.63 7

RankRating

Catchments

Total Score

Discharge Type


Land Use


Area (ha)


Residential

WESROC : All Local AuthoritiesDetermination of Priority Subcatchments JDA Consultant Hydrologists




CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

NE 1 192.3 99.8% 0.2% 0.0% 0.0% 0.0% Ocean / Dunes No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 2 0 0 2 2.25 47

NE 2 13.8 52.0% 17.0% 31.1% 0.0% 0.0% Ocean / Dunes No 4 66 14 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47

NE 3 0.9 58.4% 0.0% 41.6% 0.0% 0.0% Ocean / Dunes No 4 67 16 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47












NE 15 * 19.5 0.0% 12.0% 77.1% 10.9% 0.0% Soakwell No 1 144 34 4 0.94 0.048 3 0.0 0.0% 0 0 0 0 0 1.38 109








NE 23 14.0 0.0% 48.3% 51.7% 0.0% 0.0% Soakwell No 1 128 25 3 0.19 0.014 2 0.0 0.0% 0 0 0 0 0 1.13 154






NE 29 24.8 0.0% 100.0% 0.0% 0.0% 0.0% Soakwell No 1 90 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.75 216

NE 30 * 140.4 0.3% 15.6% 28.7% 14.8% 40.6% Ocean / Dunes via Comp Basin No 3 87 18 2 4.49 0.032 3 57.0 40.6% 3 1 0 0 1 2.63 14

NE 31 10.6 0.0% 48.4% 42.9% 8.7% 0.0% Soakwell No 1 119 23 3 0.27 0.026 3 0.0 0.0% 0 0 0 0 0 1.25 127









NE 40 0.5 0.0% 7.0% 93.0% 0.0% 0.0% River No 4 158 38 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

NE 41 5.8 0.0% 2.5% 97.5% 0.0% 0.0% River No 4 161 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

NE 42 * 18.3 0.0% 0.0% 100.0% 0.0% 0.0% Soakwell No 1 161 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 175

NE 43 1.8 0.0% 2.4% 97.6% 0.0% 0.0% River No 4 161 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

NE 44 6.3 0.0% 20.3% 79.7% 0.0% 0.0% River No 4 148 34 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

NE 45 58.2 0.0% 33.3% 66.7% 0.0% 0.0% River No 4 138 30 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 39

RatingSub Catchment

Area (ha)



Catchments

Total Score

Discharge Type


Land Use






CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

RatingSub Catchment

Area (ha)



Catchments

Total Score

Discharge Type


Land Use



NE 47 3.2 0.0% 3.7% 96.3% 0.0% 0.0% River No 4 160 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

NE 48 2.8 0.0% 7.1% 92.9% 0.0% 0.0% River No 4 157 38 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

NE 49 3.2 0.0% 36.0% 64.0% 0.0% 0.0% River No 4 136 29 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 39


NE 51 32.4 0.0% 58.0% 42.0% 0.0% 0.0% River No 4 120 23 3 0.00 0.000 0 0.0 0.0% 0 2 0 0 2 2.63 14

NE 52 39.5 0.0% 34.5% 65.5% 0.0% 0.0% River No 4 138 30 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 39

NE 53 51.8 0.0% 45.6% 52.5% 0.0% 1.8% River No 4 127 26 3 0.00 0.000 0 1.0 1.8% 1 1 0 0 1 2.63 14

NE - Railwa 16.0 84.4% 0.0% 0.0% 8.9% 6.7% Railway Reserves No 2 9 2 1 1.43 0.090 4 1.1 6.7% 1 1 0 0 1 1.88 72

CA 1 143.6 100.0% 0.0% 0.0% 0.0% 0.0% Ocean / Dunes No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.00 67



























CA 28 * 429.1 47.1% 25.5% 26.4% 0.0% 1.0% Ocean / Dunes via Comp Basin Yes 4 66 13 2 6.44 0.015 2 4.4 1.0% 1 1 2 2 1 2.75 10













CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

RatingSub Catchment

Area (ha)



Catchments

Total Score

Discharge Type


Land Use


CA 37 63.4 17.2% 12.0% 0.0% 54.9% 15.9% River No 4 56 10 2 3.99 0.063 4 10.1 15.9% 2 0 0 0 0 3.00 5

CA 38 * 12.6 56.6% 43.4% 0.0% 0.0% 0.0% River via Comp Basin Yes 4 39 4 1 1.30 0.103 4 0.0 0.0% 0 0 0 0 0 2.63 14

CA - Lake M 67.9 100.0% 0.0% 0.0% 0.0% 0.0% River No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.00 67

ST 1 5.7 0.0% 35.3% 58.1% 6.6% 0.0% Infiltration Basin / Swale No 1 131 28 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.88 203

ST 2 12.6 0.0% 28.9% 51.7% 9.3% 10.2% Infiltration Basin / Swale No 1 121 26 3 0.23 0.018 2 1.3 10.2% 2 0 0 0 0 1.38 109

ST 3 191.2 0.4% 8.8% 89.9% 0.0% 0.9% Ocean / Dunes via Comp Basin Yes 4 155 37 4 5.87 0.031 3 1.7 0.9% 1 0 1 0 1 3.13 3


CL 2 * 163.1 10.4% 45.1% 24.3% 19.1% 1.1% Lake Yes 4 94 17 2 1.21 0.007 1 1.8 1.1% 1 2 1 0 3 2.88 8





CL 7 * 1.7 0.0% 11.5% 88.5% 0.0% 0.0% Soakwell No 1 154 36 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 175



CL 10 * 6.0 0.0% 1.8% 98.2% 0.0% 0.0% Soakwell No 1 161 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 175




CL 14 5.4 3.2% 38.2% 57.8% 0.0% 0.9% Soakwell No 1 129 27 3 0.00 0.000 0 0.0 0.9% 1 0 0 0 0 1.00 175




CL 18 7.2 11.1% 17.2% 71.7% 0.0% 0.0% Soakwell No 1 132 30 4 0.58 0.080 4 0.0 0.0% 0 0 0 0 0 1.50 93



CL 21 * 128.1 0.0% 25.2% 32.9% 29.2% 12.7% River No 4 102 21 3 3.79 0.030 3 16.2 12.7% 2 0 1 0 1 3.13 3


CL 23 11.0 0.0% 0.0% 58.3% 41.7% 0.0% Soakwell No 1 122 29 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.88 203

CL 24 7.4 0.0% 29.0% 11.8% 59.2% 0.0% River No 4 87 16 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47

CL 25 * 18.5 0.0% 13.6% 84.2% 2.2% 0.0% River No 4 151 35 4 0.12 0.007 1 0.0 0.0% 0 0 0 0 0 2.63 14

CL - Railway 16.6 95.1% 0.0% 1.1% 1.1% 2.7% Railway Reserves No 2 4 1 0 2.33 0.141 4 0.4 2.7% 1 1 0 1 0 1.63 81

CO 1 4.7 99.4% 0.0% 0.6% 0.0% 0.0% Ocean / Dunes No 4 1 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.00 67






CO 7 7.8 50.3% 9.3% 0.0% 40.4% 0.0% Ocean / Dunes No 4 37 7 1 0.02 0.003 1 0.0 0.0% 0 0 0 0 0 2.25 47











CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

RatingSub Catchment

Area (ha)



Catchments

Total Score

Discharge Type


Land Use








CO 20 11.0 50.9% 0.0% 1.0% 23.0% 25.2% Ocean / Dunes No 4 27 5 1 0.00 0.000 0 2.8 25.2% 2 0 1 1 0 2.38 39



CO 23 1.4 0.0% 0.0% 3.8% 41.0% 55.3% Soakwell No 1 56 11 2 0.00 0.000 0 0.8 55.3% 4 0 0 0 0 1.25 127






CO 29 1.9 0.0% 0.0% 71.0% 29.0% 0.0% Soakwell No 1 134 32 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 175

CO 30 0.3 3.0% 0.0% 97.0% 0.0% 0.0% Soakwell No 1 156 38 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 175

CO 31 4.2 100.0% 0.0% 0.0% 0.0% 0.0% Ocean / Dunes No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.00 67







CO 38 20.6 24.9% 2.8% 0.0% 72.3% 0.0% Ocean / Dunes No 4 54 11 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47


CO 40 16.5 23.9% 0.0% 0.0% 55.5% 20.5% Ocean / Dunes No 4 46 9 1 0.00 0.000 0 3.4 20.5% 2 0 0 0 0 2.38 39




CO 44 10.1 34.1% 0.0% 0.0% 59.3% 6.5% Ocean / Dunes No 4 43 9 1 0.14 0.014 2 0.7 6.5% 1 0 0 0 0 2.50 22


CO 46 3.2 99.6% 0.0% 0.0% 0.4% 0.0% Ocean / Dunes No 4 0 0 0 0.33 0.105 4 0.0 0.0% 0 0 0 0 0 2.50 22

CO - Railway 28.8 99.9% 0.0% 0.0% 0.1% 0.0% Railway Reserves No 2 0 0 0 0.10 0.003 1 0.0 0.0% 0 0 0 0 0 1.13 154





SU 5 151.4 1.7% 8.6% 86.0% 0.8% 2.9% Ocean / Dunes via Comp Basin No 3 149 35 4 3.52 0.023 2 4.5 2.9% 1 1 2 0 3 2.75 10

SU 6 * 113.4 11.2% 0.5% 50.1% 31.3% 6.9% River No 4 107 25 3 3.02 0.027 3 7.8 6.9% 1 0 1 0 1 3.00 5

SU 7 * 88.5 0.2% 10.0% 50.6% 32.3% 6.9% River No 4 117 26 3 1.77 0.020 2 6.1 6.9% 1 1 0 0 1 2.88 8

SU 8 19.3 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.20 0.011 2 0.0 0.0% 0 0 0 0 0 2.50 22

SU 9 21.1 23.1% 68.0% 0.0% 8.8% 0.1% River No 4 68 8 1 0.00 0.000 0 0.0 0.1% 1 0 0 0 0 2.25 47

SU 10 21.3 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.89 0.042 3 0.0 0.0% 0 0 0 0 0 2.63 14

SU - Railway 12.2 99.9% 0.0% 0.0% 0.1% 0.0% Railway Reserves No 2 0 0 0 0.10 0.008 1 0.0 0.0% 0 0 0 0 0 1.13 154





CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

RatingSub Catchment

Area (ha)



Catchments

Total Score

Discharge Type


Land Use




MP 3 * 18.4 0.0% 48.3% 39.0% 12.7% 0.0% River No 4 116 22 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 39

MP 4 0.8 0.0% 95.0% 0.0% 5.0% 0.0% River No 4 89 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47

MP 5 1.5 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47


MP 7 1.4 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47



MP 10 2.4 0.0% 74.4% 25.6% 0.0% 0.0% River No 4 109 18 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47

MP 11 1.0 0.0% 58.7% 41.3% 0.0% 0.0% River No 4 120 22 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 39

MP 12 1.8 0.0% 11.0% 89.0% 0.0% 0.0% River No 4 155 37 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

MP 13 6.3 0.0% 5.9% 94.1% 0.0% 0.0% River No 4 158 38 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

MP 14 1.0 0.0% 20.2% 79.8% 0.0% 0.0% River No 4 148 34 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

MP 15 2.8 0.0% 3.2% 96.8% 0.0% 0.0% River No 4 160 39 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

MP 16 1.0 0.0% 15.5% 84.5% 0.0% 0.0% River No 4 151 35 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

MP 17 1.7 0.0% 9.6% 90.4% 0.0% 0.0% River No 4 156 37 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22

MP 18 2.4 100.0% 0.0% 0.0% 0.0% 0.0% Ocean / Dunes No 4 0 0 0 0.00 0.000 0 0.0 0.0% 0 2 0 0 2 2.25 47

MP 19 3.8 99.9% 0.1% 0.0% 0.0% 0.0% Soakwell No 1 0 0 0 0.62 0.164 4 0.0 0.0% 0 0 0 0 0 1.00 175

MP 20 1.1 0.1% 99.9% 0.0% 0.0% 0.0% Railway Reserves No 2 90 10 1 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.13 154








MP 28 3.4 0.0% 90.7% 9.3% 0.0% 0.0% River No 4 97 13 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47

MP 29 0.6 0.0% 100.0% 0.0% 0.0% 0.0% River No 4 90 10 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47

MP 30 5.7 0.0% 44.3% 55.7% 0.0% 0.0% River No 4 130 27 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.38 39

MP 31 2.1 0.0% 67.4% 32.6% 0.0% 0.0% River No 4 114 20 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47

MP 32 2.2 0.0% 97.9% 2.1% 0.0% 0.0% River No 4 92 11 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47


MP 34 15.7 0.0% 34.1% 0.0% 65.9% 0.0% River No 4 78 13 2 0.00 0.000 0 0.0 0.0% 0 1 0 1 0 2.25 47



MP 37 0.5 0.0% 1.2% 98.8% 0.0% 0.0% Soakwell No 1 162 40 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 175

MP 38 5.2 0.0% 65.9% 34.1% 0.0% 0.0% Soakwell No 1 115 20 3 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 0.88 203

MP 39 13.6 0.0% 48.8% 51.2% 0.0% 0.0% Soakwell No 1 127 25 3 0.00 0.000 0 0.0 0.0% 0 1 0 0 1 1.00 175

MP - Railway 9.9 100.0% 0.0% 0.0% 0.0% 0.0% Railway Reserves No 2 0 0 0 0.60 0.060 4 0.0 0.0% 0 2 0 0 2 1.75 78

FR 1 4.9 0.0% 16.1% 0.0% 83.9% 0.0% River No 4 74 14 2 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.25 47


PG 2 * 43.8 0.0% 25.9% 74.1% 0.0% 0.0% River No 4 144 32 4 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 2.50 22







CommercialTN TP

Length of Road (km)

Density (km/ha)




Sites

Fuel Storage

Remediated

RatingSub Catchment

Area (ha)



Catchments

Total Score

Discharge Type


Land Use



PG - Railwa 0.8 99.1% 0.1% 0.0% 0.8% 0.0% Railway Reserves No 2 1 0 0 0.00 0.000 0 0.0 0.0% 0 0 0 0 0 1.00 175

WESROC : All Local AuthoritiesRegional Ranking of Priority Subcatchments JDA Consultant Hydrologists

SU 1 * 243.8 3.50 1 1

SU 2 * 50.4 3.50 1 2

CL 21 * 128.1 3.13 3 3

SU 3 * 241.6 3.00 4 4

SU 6 * 113.4 3.00 4 5

CA 37 63.4 3.00 4 6

CL 2 * 163.1 2.88 7 7

SU 7 * 88.5 2.88 7 8

CA 28 * 429.1 2.75 9 9

SU 5 151.4 2.75 9 10

CA 34 83.4 2.75 9 11

CA 33 26.4 2.75 9 12

ST 3 191.2 2.63 13 13

NE 30 * 140.4 2.63 13 14

NE 53 51.8 2.63 13 15

NE 51 32.4 2.63 13 16

CA 36 25.5 2.63 13 17

SU 10 21.3 2.63 13 18

CA 35 20.7 2.63 13 19

CL 25 * 18.5 2.63 13 20

CA 38 * 12.6 2.63 13 21

SU 4 * 85.9 2.50 22 22

PG 2 * 43.8 2.50 22 23

SU 8 19.3 2.50 22 24

CO 44 10.1 2.50 22 25

NE 44 6.3 2.50 22 26

MP 13 6.3 2.50 22 27

NE 41 5.8 2.50 22 28

NE 47 3.2 2.50 22 29

CO 46 3.2 2.50 22 30

MP 15 2.8 2.50 22 31

NE 48 2.8 2.50 22 32

NE 43 1.8 2.50 22 33

MP 12 1.8 2.50 22 34

MP 17 1.7 2.50 22 35

MP 16 1.0 2.50 22 36

MP 14 1.0 2.50 22 37

NE 40 0.5 2.50 22 38

NE 45 58.2 2.38 39 39

NE 52 39.5 2.38 39 40

MP 3 * 18.4 2.38 39 41

CO 40 16.5 2.38 39 42

CO 20 11.0 2.38 39 43

MP 30 5.7 2.38 39 44

NE 49 3.2 2.38 39 45

MP 11 1.0 2.38 39 46

NE 1 192.3 2.25 47 47

CA 32 21.8 2.25 47 48

SU 9 21.1 2.25 47 49

CO 38 20.6 2.25 47 50

MP 34 15.7 2.25 47 51

NE 2 13.8 2.25 47 52

CO 7 7.8 2.25 47 53

CL 24 7.4 2.25 47 54

FR 1 4.9 2.25 47 55

MP 28 3.4 2.25 47 56

MP 10 2.4 2.25 47 57

MP 18 2.4 2.25 47 58

MP 32 2.2 2.25 47 59

MP 31 2.1 2.25 47 60

MP 5 1.5 2.25 47 61

MP 7 1.4 2.25 47 62

NE 3 0.9 2.25 47 63

MP 4 0.8 2.25 47 64

MP 29 0.6 2.25 47 65

CO 43 4.3 2.13 66 66

CA 1 143.6 2.00 67 67

CA - Lake Monger 67.9 2.00 67 68

CO 1 4.7 2.00 67 69

CO 31 4.2 2.00 67 70

CO 27 0.8 2.00 67 71

NE 24 147.4 1.88 72 72

CO 39 21.9 1.88 72 73

NE - Railway Reserv 16.0 1.88 72 74

Adj RankTotal Score RankSub Catchment

Area (ha)

Catchments


Area (ha)

Catchments

CO 28 6.7 1.88 72 75

CO 16 3.8 1.88 72 76

CO 33 3.6 1.88 72 77

CA 6 98.6 1.75 78 78

MP - Railway Reserv 9.9 1.75 78 79

CA 13 9.4 1.75 78 80

CA 29 93.5 1.63 81 81

NE 21 19.8 1.63 81 82

CL - Railway Reserve 16.6 1.63 81 83

CO 17 13.7 1.63 81 84

PG 4 * 13.2 1.63 81 85

NE 20 12.8 1.63 81 86

NE 34 6.0 1.63 81 87

MP 21 6.0 1.63 81 88

CA 12 4.4 1.63 81 89

CL 16 3.7 1.63 81 90

CL 17 2.2 1.63 81 91

CO 45 0.3 1.63 81 92

NE 27 90.3 1.50 93 93

NE 5 * 57.6 1.50 93 94

NE 37 35.0 1.50 93 95

NE 17 33.0 1.50 93 96

CL 19 * 25.4 1.50 93 97

CO 26 22.8 1.50 93 98

CA 23 20.8 1.50 93 99

CO 19 13.7 1.50 93 100

CO 24 11.0 1.50 93 101

CL 18 7.2 1.50 93 102

NE 35 6.1 1.50 93 103

CA 22 5.8 1.50 93 104

NE 9 * 4.8 1.50 93 105

CO 14 4.1 1.50 93 106

CO 21 3.9 1.50 93 107

PG 3 2.1 1.50 93 108

NE 36 * 67.5 1.38 109 109

MP 8 60.3 1.38 109 110

PG 1 43.2 1.38 109 111

CA 21 33.1 1.38 109 112

CA 16 30.3 1.38 109 113

NE 25 * 27.4 1.38 109 114

MP 1 25.4 1.38 109 115

NE 26 * 22.7 1.38 109 116

CO 13 20.4 1.38 109 117

NE 15 * 19.5 1.38 109 118

NE 13 * 16.0 1.38 109 119

NE 32 * 13.4 1.38 109 120

ST 2 12.6 1.38 109 121

CO 35 9.9 1.38 109 122

MP 36 8.2 1.38 109 123

CA 30 * 5.2 1.38 109 124

CL 13 1.7 1.38 109 125

CO 15 * 0.4 1.38 109 126

NE 39 * 104.1 1.25 127 127

CA 11 94.5 1.25 127 128

NE 18 * 50.4 1.25 127 129

CA 15 49.2 1.25 127 130

CA 14 49.2 1.25 127 131

CA 2 48.3 1.25 127 132

CA 19 36.1 1.25 127 133

CA 4 36.1 1.25 127 134

CA 18 32.9 1.25 127 135

NE 14 26.7 1.25 127 136

NE 12 24.7 1.25 127 137

CA 27 * 21.1 1.25 127 138

CA 26 * 18.1 1.25 127 139

CA 25 * 13.4 1.25 127 140

NE 11 * 13.3 1.25 127 141

CL 12 12.1 1.25 127 142

CO 36 10.7 1.25 127 143

NE 28 * 10.7 1.25 127 144

NE 31 10.6 1.25 127 145

MP 33 10.4 1.25 127 146

MP 23 9.7 1.25 127 147

CL 22 9.5 1.25 127 148

CA 9 9.4 1.25 127 149

CL 4 8.3 1.25 127 150

NE 22 * 2.6 1.25 127 151

CL 11 * 1.4 1.25 127 152

CO 23 1.4 1.25 127 153

MP 9 46.9 1.13 154 154


Area (ha)

Catchments

NE 10 * 38.9 1.13 154 155

NE 19 37.3 1.13 154 156

NE 38 34.2 1.13 154 157

CO - Railway Reserv 28.8 1.13 154 158

MP 2 24.8 1.13 154 159

MP 6 22.3 1.13 154 160

CL 1 * 21.7 1.13 154 161

MP 24 21.2 1.13 154 162

CL 3 18.4 1.13 154 163

PG 5 * 14.1 1.13 154 164

NE 23 14.0 1.13 154 165

CL 15 * 12.7 1.13 154 166

SU - Railway Reserv 12.2 1.13 154 167

CL 20 6.8 1.13 154 168

NE 33 5.9 1.13 154 169

CO 22 4.0 1.13 154 170

CO 18 1.2 1.13 154 171

MP 20 1.1 1.13 154 172

CO 41 0.3 1.13 154 173

CO 42 0.1 1.13 154 174

NE 50 51.0 1.00 175 175

CA 7 51.0 1.00 175 176

MP 26 20.6 1.00 175 177

NE 42 * 18.3 1.00 175 178

CO 5 * 17.7 1.00 175 179

MP 39 13.6 1.00 175 180

CO 4 * 13.5 1.00 175 181

MP 22 13.2 1.00 175 182

CL 8 * 12.8 1.00 175 183

CO 3 11.8 1.00 175 184

CA 5 * 11.5 1.00 175 185

CL 9 8.3 1.00 175 186

CA 20 7.8 1.00 175 187

NE 46 6.9 1.00 175 188

CO 34 6.6 1.00 175 189

CL 10 * 6.0 1.00 175 190

CO 6 5.5 1.00 175 191

CL 14 5.4 1.00 175 192

CA 31 4.7 1.00 175 193

MP 19 3.8 1.00 175 194

CA 8 * 3.0 1.00 175 195

CO 25 3.0 1.00 175 196

CO 29 1.9 1.00 175 197

CO 11 1.7 1.00 175 198

CL 7 * 1.7 1.00 175 199

PG - Railway Reserv 0.8 1.00 175 200

MP 37 0.5 1.00 175 201

CO 30 0.3 1.00 175 202

CA 17 112.9 0.88 203 203

CA 24 * 94.9 0.88 203 204

CO 32 35.1 0.88 203 205

NE 4 25.5 0.88 203 206

CL 6 21.4 0.88 203 207

NE 8 15.2 0.88 203 208

CL 23 11.0 0.88 203 209

MP 35 8.3 0.88 203 210

CO 37 7.1 0.88 203 211

CA 3 7.0 0.88 203 212

ST 1 5.7 0.88 203 213

MP 38 5.2 0.88 203 214

CO 12 3.3 0.88 203 215

CA 10 33.8 0.75 216 216

MP 27 28.3 0.75 216 217

NE 29 24.8 0.75 216 218

NE 16 15.0 0.75 216 219

NE 6 6.0 0.75 216 220

CL 5 3.5 0.75 216 221

CO 8 2.7 0.75 216 222

MP 25 1.8 0.75 216 223

CO 9 1.1 0.75 216 224

CO 10 0.2 0.75 216 225

NE 7 1.6 0.63 226 226

CO 2 0.4 0.50 227 227

APPENDIX 5

New South Wales EPAEducation Campaign Materials

Examples

Bin your butts A single cigarette butt or bottle top might

not seem like much. But in their thousands

and in combination with other litter, they cause

serious pollution. Litter can block drains and

cause flooding. It looks awful too.

What you can do✔ Put your cigarette butts and other litter in the bin.

✔ Pitch in and help clean up littered areas.

✔ If there is no bin handy, hold onto your litter until you find one.

✔ Carry a container for your cigarette butts.

Wash your car on the grass If you wash your car in the street or on

your driveway, detergents, mud, oil and

grease can wash directly into the

stormwater system. Many detergents

contain phosphates which over-fertilise

waterways and can lead to a build up of

toxic algae which is harmful to fish and

humans too.

What you can do✔ Try to wash your vehicle on a grassy area or over gravel.

✔ If you don’t have a suitable area, visit a friend or relative who does.

✔ Use as little detergent as you can and pour any leftover soapy water onto the lawn.

✔ Use a service station car washing bay or a car wash that recycles water.

✔ When cleaning under the car, check for any fluid leaks and get them repaired.

Stormwaterpollution

T h e d i f f e r e n c e i s y o u

Environment Protection Authority 59-61 Goulburn Street, Sydney ■ PO Box A290, Sydney South 1232Phone: (02) 9995 5000 (switchboard) ■ Fax: (02) 9995 5999Phone: 131 555 (information & publications requests)E-mail: [email protected] ■ Website address: www.epa.nsw.gov.au

Printed on recycled paper ■ EPA 2000/30 ■ April 2000

THE DRAIN IS JUST FOR RAIN

Gutters and drains take rainwater from our streets straight into rivers, lakes, harbours and oceans. So when it rains,stormwater runoff can carry with it pollution from around ourhomes and streets ... into the waterways we swim in and where animals and plants live.

If we stop pollution entering gutters and drains in the first place, we can help keep

our waterways clean and healthy.That way, they will provide a better environment

for us and for animals and plants.

We can help prevent stormwater pollution from ruining our waterways by taking

steps to stop detergents, paints, leaves and grass clippings, cigarette butts and other

litter from ending up in our gutters and drains.

Sweep them up before theywash awayEven natural things like leaves, garden

clippings and soil can harm our waterways.

In bushland or in our gardens, leaves are

scattered and decay where they fall.

But when they are washed into the

stormwater system they become

concentrated – imagine the impact of all the leaves and dirt in all the streets from

five kilometres around washing directly into your local waterway.

It causes big problems.When leaves and

clippings decay in water, they use up

oxygen.Taking oxygen away from the

water can kill plants, fish and other animals

that live in our waterways. Soil is a

problem too. It makes waterways cloudy

and can silt them up. Silt can suffocate fish

by clogging their gills.

What you can do✔ Sweep your gutters and driveways rather than hosing them down.

✔ Put leaves in the compost or on the garden as mulch.

✔ Rake up grass clippings then mulch or compost them.

✔ Cover piles of soil, sand or mulch to stop them washing into drains.

✔ Build barriers around your garden beds to contain the soil (and any fertilisers you are using).

✔ Plant grass where soil is exposed.

Pick up your dog’s droppings When dog droppings are left on the footpath they can wash into our waterways, where they can increase the level of bacteria and make your local waterway unsafe for swimming.

What you can do✔ Train your dog to go in your garden.

✔ When you’re out, pick up your dog’s droppings with a plastic bag and put them in the bin.

Clean up paint the right way Cleaning paint brushes and rollers into gutters or drains puts chemicals in the waterwhich can poison frogs, fish and other aquatic life.

What you can do✔ When using water-based paint, clean

up over soil.

✔ When using oil-based paint:

- keep paint, turps and solvents clear of gutters and drains

- re-use turps once the paint has settled

- allow unused paint to dry out and then put it in the bin.

Why should I care about Stormwater Pollution?

What is Stormwater?Stormwater is rain that falls on roofs or paved areas likedriveways, roads and footpaths. This water is carried awayby a system of stormwater pipes that is separate from thesewage system. It eventually ends up in our rivers and theocean.

Why is stormwater pollution an important issue thatI need to care about?As stormwater travels over the land, it picks up all kinds ofchemicals and materials that are not naturally found in ourwaterways. Some are toxic even in small amounts. Others,such as nutrients, are not poisonous but may be producedin such great quantities that nature can’t cope. This resultsin pollution of our waterways that can kill plants andanimals that live in the water. Pollution of our waterwayscan also mean we can’t boat, swim or fish because it isunpleasant or even unsafe.

What is in stormwater pollution?Rubbish and pollution gets washed into our waterways:• ‘Natural’ pollution such as dog droppings, leaves and

garden clippings• Chemical pollution such as car washing detergents and

fertilisers• Litter

What is being done to stop stormwater pollution?In 1997, the State Government committed $60 million overthree years to tackle stormwater pollution. Some of it goesto fund local projects, including building ‘pollution traps’which catch pollution before it has a chance to enter thewaterways.

Councils and the EPA are also undertaking educationcampaigns to prevent the pollution going down the drain inthe first place.

COUNCILLOGO

For further details contact:

Why are words beingpainted on my drain?

Council, local residents and industry are teaming up aspart of The Drain is Just for Rain campaign to show thatif people put litter down the drain, it ends up polluting thewaterways where we swim, fish and go boating.

When it rains, leaves and litter in the gutter get washeddown the drain to our beaches, creeks and lakes.

What goes down the drain can betoxic for wildlife and makes swimming or fishingunpleasant or even unhealthy.

The words painted on your drain are a reminder thatwildlife is affected when anything other than rainwateris sent down the drain.

What Can You Do to ReduceStormwater Pollution?

1. Don’t put rubbish and pollution down the drain,including pet droppings, leaves and grass clippings.

2. Wash your car on the grass or over gravel, not on the street.

3. Keep your driveways and gutters clean, even of leaves and grass clippings(sweep them up and put them in your compost bin).

4. Work with your local Council to stencil more drains.

For furtherdetails contact: COUNCIL

LOGO

�

Everything that goes into our drains ends up in ourwaterways: Remember the Drain is Just for Rain

DO

Here’s a few simple things you can do to improve the quality of water where you swim, fish or boat.

In the garden...• Sweep gutters, driveways and back

yards regularly and put the leavesand clippings on the garden,compost or in the bin.

In the street...• Clean up pet droppings and dispose

of them in the garden, rubbish bins,or toilet.

With the car...• Wash your car over gravel or grass

and use a minimum amount ofdetergent.

Renovating...• Wash water-based paint from

brushes over the lawn.• Allow unused paint in tins to dry

out and then put in the bin.

✗DON’TIn the garden...• Hose leaves, dirt and grass

clippings down the drain or intothe gutter.

In the street...• Drop packaging or cigarette butts

on the ground.

With the car...• Wash the car in the street.• Empty the bucket down the drain.

Renovating...• Wash brushes over the drain.

COUNCILLOGO

For furtherinformation contact:

If so, come along to a meeting at:

To find out about:

Date:

Time:

For further information contact:

Do You Want Our Rivers,Creeks and Lakes to be Clean?

Do You Want to Boat, Swim or Fish in our Waterways Without Worrying About Pollution?

COUNCILLOGO