State of the Environment Report

EXECUTIVE SUMMARY

There is a growing focus in the community on restoration of urban and other areas damaged by human actions. We want to clean up the environment close to where we live - our air, our open spaces, and our water.

This study examines the potential for restoration of one such damaged system - the waterways of the Merri Catchment, in Melbourne’s northern suburbs. The Merri Creek rises in the foothills of the Great Dividing Range near Wallan, approximately sixty kilometres north of Melbourne, and flows south, through rural, industrial and residential areas to its confluence with the Yarra River near Dights Falls in the inner city suburb of Abbotsford. The Merri Creek itself is approximately 80 kilometres long and the catchment drains an area of approximately 400 square kilometres.

This study presents all the available information on the state of the waterways of the Merri Catchment. It identifies, as far as possible, the problems resulting from human activities.

Throughout the study the principles of Integrated Catchment Management have been used, in particular the concepts of: • recognition of the intrinsic worth of the natural environment • an interdisciplinary approach and a systems perspective • concern to include community values • an integrated environmental and socio-economic approach

The most important findings of the State of the Environment Report are that: • Agricultural practices - such as removal of riparian vegetation, drainage of wetlands and stock trampling of stream banks - are a major cause of aquatic ecosystem degradation. • Urban development has massively altered the flow and the water quality of the waterways, for example by increasing the quantity of stormwater which carries a high load of contaminants. • Sewage treatment in the catchment is inadequate, with effluent from Craigieburn Sewage Treatment Plant and from unsewered industrial and residential areas contributing significantly to the nutrient problem in some parts of the Merri Catchment. • Industrial activities still pollute the waterways - mainly from inadequate storage, disposal and transport of materials such as chemicals. • Despite these obvious problems, there are still long stretches of the Merri Creek that have National, State, Regional or Local biological significance, with surviving remnant populations of increasingly rare species such as the Growling Grass Frog, Freshwater Blackfish and Rufous Night Heron and habitats such as the endangered Western (Basalt) Plains Native Grassland. • There is strong community support for waterway restoration.

i Waterways of the Merri Catchment

Page ii State of the Environment Report

Table of Contents

1. INTRODUCTION ...... 9

1.1 The Merri Creek and its Catchment...... 9

1.2 Background to the Report...... 10

1.3 The Merri Creek Management Committee...... 12

1.4 Monash University Master of Environmental Science ...... 12

1.5 Methodology and Methods...... 13

1.6 Structure of this Report ...... 15

1.7 A Journey down the Merri Creek ...... 2

2. THE HUMAN ENVIRONMENT ...... 11

2.1 Introduction...... 9 2.1.1 Previous work...... 9

2.2 Changes in Human Use since Settlement...... 12 2.2.1 Introduction...... 12 2.2.2 Agriculture ...... 12 2.2.3 Industrialisation...... 14 2.2.4 Urbanisation ...... 16

2.3 Current Community Attitudes and Uses ...... 20

2.4 Agencies and Institutions ...... 23 2.4.1 The Players...... 23

2.5 Legislation, Strategies and Policies ...... 29 2.5.1 The Environment Protection Act 1970 (Vic.) ...... 29 2.5.2 Other State legislation ...... 34 2.5.3 Commonwealth strategies, legislation and policies...... 35

2.6 Current Arrangements ...... 36

2.7 Conclusions...... 37

3. GEOMORPHOLOGY AND FLOW ...... 45

3.1 Introduction...... 43 3.1.1 Previous work...... 43

3.2 “Natural” states ...... 45

3.3 Existing states...... 45 3.3.1 The Merri Creek...... 46 3.3.2 Summaries of the Significant Tributaries...... 50 3.3.3 Wetlands...... 54 3.3.4 Water Harvesting ...... 55

iii Waterways of the Merri Catchment

3.3.5 Stormwater ...... 55 3.3.6 Floods ...... 58 3.3.7 Groundwater...... 59

3.4 Conclusions...... 60

4. WATER QUALITY...... 67

4.1 Introduction...... 71 4.1.1 Previous Work...... 71 4.1.2 Scope of this section...... 73

4.2 ‘Natural’ states...... 73

4.3 Water quality parameters as indicators of stream health...... 74

4.4 Existing states...... 74 4.4.1 Physical and chemical parameters...... 74 4.4.2 Biological Parameters...... 87 4.4.3 Groundwater quality...... 91

4.5 Conclusions...... 96

5. AQUATIC ECOLOGY...... 99

5.1 Introduction...... 96 5.1.1 Previous work...... 96 5.1.2 Scope of this section...... 97

5.2 ‘Natural’ states...... 98

5.3 Existing states...... 98 5.3.1 Streams ...... 100 5.3.2 Wetlands...... 100 5.3.3 Riparian Vegetation and Aquatic Plants in the Merri Catchment...... 101 5.3.4 Micro-organisms...... 103 5.3.5 Invertebrates ...... 103 5.3.6 Fish ...... 104 5.3.7 Reptiles and Amphibians...... 108 5.3.8 Water Birds...... 110 5.3.9 Aquatic Mammals...... 113

5.4 Conclusions...... 114

6. REPORT CONCLUSIONS ...... Error! Bookmark not defined.

7. REFERENCES ...... ERROR! BOOKMARK NOT DEFINED.

8. APPENDICES ...... 119

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List of Maps Map 1 The Waterways of the Merri Catchment ______11 Map 2 Land-use types in the Merri Catchment ______19 Map 3 Merri Creek Catchment and Municipal Boundaries ______26 Map 4 Reaches of the Merri Creek ______48 Map 5 Drains to the urban waterways of the Merri Catchment ______57 Map 6 Sediment sampling sites 1995 heavy metal study. ______76 Map 7 Location of landfills in the urban portion of the Merri Catchment. ______89 Map 8 Zoning of the Merri waterways according to the distribution of habitat, flora and fauna___ 99

List of Figures Figure 1 Runoff hydrographs for different percentages of urbanisation of a catchment______56 Figure 2 Concentration of metal in sediments downstream along Merri Creek ______78

List of Boxes Box 1 Impacts of Agriculture on Waterways ______11 Box 2 Impacts of Industrial Activity on Waterways ______15 Box 3 Impacts of Urbanisation on Waterways ______16 Box 4 Community Consultation Report ______21 Box 5 State environment protection policy ______29 Box 6 SEPPs affecting the Merri Catchment______30 Box 7 EPA Licences to Discharge Waste to Water ______32 Box 8 Rates of Change in the Merri Catchment______44 Box 9 Water Quality Indicators______68 Box 10 Biological Indicators of Stream Health ______83 Box 11 Human influences on waterbirds ______111

v Waterways of the Merri Catchment

List of Tables Table 1 EPA Water Discharge Standard for Craigieburn STP as from September 1993 ______23 Table 2 Summary of Key Pollutants from Human Activities ______19 Table 3 Extractive Industry Discharge Licences______33 Table 4 Sewage & Sullage Wastewater Discharge Licences ______33 Table 5 Overview of surveys examining geomorphology and flow in the Merri______39 Table 6 Overview of surveys examining water quality in the Merri Catchment. ______61 Table 7 Water Quality Parameters as Indicators ______71 Table 8 Biological Indicators of Organic Pollution ______84 Table 9 A summary of the average chemistry from 105 bores in the Merri Catchment ______86 Table 10 A summary of the average chemistry from 67 bores in the upper portion of the Merri Catchment______86 Table 11 A summary of the average chemistry from 38 bores in the lower portion of the Merri Catchment. ______86 Table 12 Landfill sites and reclaimed quarries and type of landfills in the urban portion of the Merri Catchment ______88 Table 13 Evaluation of Pollution issues against SEPP______92 Table 14 Overview of flora and fauna surveys in the Merri Catchment ______93 Table 15 Fish in the Merri Catchment and their environmental requirements______106 Table 16 Reptiles and Amphibians in the Merri Creek ______109 Table 17 Distribution of waterbirds in Merri Catchment ______112 Table 18 Sites at which the Water Rat was found in the Merri Catchment______114

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Appendices Referred to in the Report

Appendix 1 State Environment Protection Policy W-29 ______119 Appendix 2 State Acts other than the Environment Protection Act (1970).______120 Appendix 3 Other Commonwealth Acts and Strategies ______121 Appendix 4 Summary of monitoring programmes and reports analysing the water quality of the Merri Creek. ______122 Appendix 5 Mean concentrations (mg/kg dry weight) of heavy metals in sediments (<62 mm size fraction) collected in April 1995. ______132 Appendix 6 A summary of existing Sediment Guidelines (in mg/kg) from overseas ______132 Appendix 7 Rock shale standard - as a measure of background sediment concentrations ____ 132 Appendix 8 Concentrations (mg/kg dry weight) of heavy metals associated with each sediment phase (August 1995). ______133 Appendix 9: Percentage of total metal concentration associated with each sediment fraction (Aug 1995)______134 Appendix 10 Adsorption of zinc to Merri Creek sediment (Barry Road)______137 Appendix 11 Summary of guidelines for protection of aquatic ecosystems______138 Appendix 12 Descriptions of the Riparian and In-stream Vegetation of Merri Creek and some of its Wetlands and Tributaries. ______142 Appendix 13 General Descriptions of Vegetation types in the Merri Creek Catchment ______145 Appendix 14 Fish in the Merri Catchment______147

vii Waterways of the Merri Catchment

Acknowledgments

A number of people have provided valuable assistance and advice throughout this project, which has been greatly appreciated:

Our supervisors: Paul Bishop Graduate School of Environmental Science, Monash University (Clayton). Barry Hart CRC for Freshwater Ecology, Monash University (Caulfield). D.C. “Bear” McPhail Department of Earth Sciences, Monash University (Clayton). David Mercer Department of Geography, Monash University (Clayton).

The staff at the Merri Creek Management Committee, in particular: Rod McLellan Manager. Tony Faithfull Conservation Planning Officer Janine Lawrie Environmental Education Officer Freya Merrick Water Quality Research Officer

The participants in group discussions and meetings: Sandra Brizga Consultant. Peter Christoff Department of Politics, University of Melbourne. Neil Craigie Consultant, N.M. Craigie & Associates. Gordon Davies Director, Catchment & Drainage Division, Melbourne Water. Lisa Dixon Freshwater Studies, EPA. Simon Fell Community StreamWatch Coordinator, MPW. Anne Graesser Senior Environmental Scientist, MPW Trevor Hausler Friends of Merri Creek Tony Ladson Department of Engineering, University of Melbourne. Vin Pettigrove Manager, Waterways & Drainage Division, MWC Nick Ronan Manager, Waterways & Drainage Division, MWC Max Sargent Friends of Merri Creek David Taylor Friends of Merri Creek Kerry Wailes Environmental Officer, City of Whittlesea Terry White Consultant, Community StreamWatch.

Other people who have provided information at various stages. Chris Chesterfield MPW. Russell Costello EPA, Senior Project Officer. Kevin Dawson Yarra Valley Water. Anne Devereaux EPA, Yarra Region. Kathryn Fergusson EPA (NSW). David Hebblethwaite EPA, Yarra Region. John Koehn Freshwater Fish Management Branch, Arthur Rylah Institute. Phil Mitchell WaterEcoscience. Bill O’Connor Freshwater Fish Management Branch, Arthur Rylah Institute. Horrie Poussard YarraCare. Nick van Roosendael Plantiwise Nursery, Mernda. Melody Serena Australian Platypus Conservancy. Andy Shugg Grounderwater Management & Protection, DNRE. Don Williams EPA, Yarra Region. Allan Webster DNRE, Melbourne region.

Page viii State of the Environment Report - Human Environment

State of the Environment Report

This report summarises the current state of knowledge about the waterways of the Merri Catchment.

This report has been produced for and with the assistance of the Merri Creek Management Committee (Inc.). It is based on a document produced by the authors as a course requirement of the Monash University Masters of Environmental Science degree.

1. Introduction

This report presents a State of the Environment Report on the aquatic ecosystem of the Merri Catchment. It is intended to;

• provide a summary of the current state of knowledge about the waterways of the Merri Creek catchment, in terms of human influences, water quality, flow, geomorphology and aquatic ecology • highlight the most important factors causing degradation.

This report is designed to be a source of reference material for anyone involved in managing the Merri Catchment, or simply with an interest in these waterways. It also presents an essential requirement towards the production of an integrated management plan for the Merri Catchment. It is vital to ensure that a common understanding about the interacting processes within the system is developed between agency staff, stakeholders and the broader community.

Over the past few decades the Merri Catchment has been the subject of a considerable number of studies relative to many other urban Australian streams. In particular, the Merri Creek Management Committee (MCMC) has worked with Melbourne Water to produce a series of reports on the catchment. Other agencies, such as the Department of Natural Resources and Environment and Environment Protection Agency, as well as various independent consultants have also collected and presented data. However, this information has never before been condensed and analysed in one document specifically relating to the Catchment’s waterways.

1.1 The Merri Creek and its Catchment

The Merri Creek rises in the rural foothills of the southern Victorian portion of the Great Dividing Range near Wallan, approximately sixty kilometres north of Melbourne, and flows south to its confluence with the Yarra River near Dights Falls in the inner city suburb of Abbotsford. The Merri Creek itself is approximately 80 kilometres long and the catchment drains an area of slightly less than 400 square kilometres.

The upper three quarters of the catchment is predominantly rural, the lower quarter predominantly residential and urban. The large town of Craigieburn is situated midway along the Merri Creek, a little further downstream is the dense industrial area around

9 Waterways of the Merri Catchment

Somerton, Campbellfield and Thomastown and further south are the outer suburbs of Melbourne.

Although the Merri Creek itself is the main watercourse in the catchment, a number of tributaries join the Merri Creek and are an important part of the Merri Catchment (see Map 1). The major tributaries are; Malcolm Creek which is in a predominantly rural area and joins the Merri Creek in Somerton, Kalkallo Creek which draws water off the hills west of Beveridge flowing southward to join the Merri Creek near Donnybrook Road, Merlynston Creek which joins the Merri Creek in urban Fawkner and Edgars Creek, the largest tributary, which flows through rural, industrial and urban land before joining the Merri Creek in Preston.

The headwaters of the Merri Creek are in an area of mostly Silurian sedimentary rocks. Further downstream the streams of most of the Merri Catchment flow through areas of Newer Basalts. In its lower reaches Edgars Creek also flows through areas of Silurian sedimentary rock (Mitchell & Dunn, 1993).

1.2 Background to the Report

The Merri Creek has been the subject of recent efforts to return it to a more “natural” state. The creek is affected by the whole range of issues associated with agricultural, industrial and residential land use. Concerns in the community about degradation of the creek and its surrounding parklands arising from increased urban development led to the founding of the Merri Creek Management Committee (MCMC) in 1989. The MCMC is an independent advisory and managerial body with representatives from local and State Government and the local community and is funded by member agencies. The committee has developed a concept plan to improve the creek, which states as its vision;

To achieve a healthy living stream flowing through an attractive bushland environment which provides habitat for native animals and is valued by the community as a peaceful, passive open space haven. To protect the natural and cultural features of the Merri Creek corridor through sensitive management which will provide a lasting benefit for the community. (MPW, 1994)

The local community of the Merri Creek has already communicated its support for restorative work on the creek. In a 1992 survey conducted of 417 local residents, water quality of the creek was ranked as the most important feature of the parklands requiring attention (MCMC, 1993).

Through the concerted efforts of the MCMC, state government agencies, local government and members of the community, much work has already been done to restore sections of the Merri Catchment. In particular, a great deal of work has been carried out to increase the size and quality of parklands along the Merri Creek by re-establishing native vegetation. However, little work has been carried out to date to restore the aquatic or instream area of the waterways of the catchment.

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Map 1 The Waterways of the Merri Catchment

11 Waterways of the Merri Catchment

1.3 The Merri Creek Management Committee

The Merri Creek Management Committee Inc. (MCMC) was established in 1989 by local community groups, local councils and the State Government. It carries out restoration and education work in the Merri Catchment, particularly of the urban reaches of the Merri Creek. It aims to provide a new model for urban creek management.

In addition to carrying out revegetation work along the creek parklands, the MCMC also carries out various education programs in the catchment, such as a recent project with market traders to reduce the amount of litter entering stormwater drains, production of materials for schools, and various publications, such as Plants of the Merri Merri; a Home Gardener’s Guide to using indigenous plants in the Northern Suburbs of Melbourne. They also carry out lobbying to protect the creek and adjacent areas, provide environmental advice to local councils and carry out research into environmental and heritage resources of the Merri Creek.

The MCMC employs a staff consisting of a core of permanent staff and varying numbers of short-term employees. The core consists of a manager who carries out program management, planning advice and promotion, a revegetation crew of 4-10 people overseen by a conservation program manager and an education program co-ordinator. They also employ additional staff carrying out other programs.

The MCMC is controlled by a board of 18 directors consisting of two places for each of the five member councils, two representatives from Melbourne Water, , and six community representatives from the Friends of Merri Creek. Funding for staff and projects comes from a variety of sources, including grants from member organisations and other grants programs and donations.

1.4 Monash University Master of Environmental Science

In 1973 Monash University enrolled the first master’s degree candidates in environmental studies in Australia. Since that time almost half of all Australians holding master’s degrees in this field have graduated through the Monash program.

The great flexibility of the Monash program has allowed it to adapt to the continuously varying awareness and needs of the community.

In 1996 the program enrolled some 150 post-graduate students with very diverse backgrounds. This large number enhances the flexibility of the course and offers the individual student an exceptional opportunity for interacting with other candidates with a wide range of skills and experiences.

Goals and Aims The goal of the Graduate School is the promotion of understanding of the interactions of ecological and social processes, leading to action to ensure a sustainable world. To achieve this, the school focuses on: • research and post-graduate education in environmental analysis and management;

Page 12 State of the Environment Report - Human Environment

• linking and integrating perspectives derived from the sciences and humanities in relation to socio-environmental processes, environmental policies, and management strategies; • understanding the social and intellectual contexts within which disciplinary understanding and knowledge are generated and used.

1.5 Methodology and Methods

The methodology has been driven by an integrated catchment management approach. Accordingly, we have used a combination of consultative and participatory processes and technical science to achieve our objectives. The framework used has been adapted from that described by the Water Quality Guidelines Task Group (1994).

Six principal activities have been carried out: 1. Scoping of the issues 1. Collation of the existing knowledge base about the historical and current states of the aquatic ecosystem of the Merri Catchment; 1. Articulation of ecosystem goals and staged targets 1. Development of ecosystem health indicators to gauge progress towards ecosystem goals and objectives 1. Targeted primary research and monitoring

These activities were largely carried out in a step process, but with considerable iteration and overlap. Step 5, Targeted primary research, took place concurrently with the other steps.

The issues were scoped by the research team together with the Merri Creek Management Committee, and through two group meetings with panels of “experts” from government agencies and environmental consultancies.

Once the issues had been scoped, available data on the Merri Catchment were collated and analysed, and are presented in this report. Information was collected through literature reviews and discussions with specialists. Two areas which seemed to have been inadequately studied and seemed to be potential major problems in the creek were made the focus of targeted research; ie firstly, the extent and fate of heavy metal pollution of the stream sediments of the Merri Creek and, secondly, the impact of landfill sites on the water quality of the Merri Creek.

13 Waterways of the Merri Catchment

1.5.1 Targeted Primary Research

Several areas of primary research were undertaken and are included in this report. These include:

Heavy Metal Pollution of Stream Sediments in the Merri Creek

Mitchell & Clark (1992) identified heavy metal contamination of the sediments of Merri Creek and suggested this as a potential cause of the decline in the diversity and abundance of the macroinvertebrate community. However, insufficient information was available to determine the extent and potential impact of this contamination. This study was chosen to further investigate this problem. By assessing the distribution of the heavy metals between the four broad sediment components (exchangeable, reducible, organic and residual), this study identifies how much of this contamination is available to impact on the aquatic ecosystem, and how much is tightly bound with little chance of impact. By identifying the relative distribution amongst the four phases, it will also be possible to make some prediction of the stream conditions, such as acidity, saline water or low oxygen, which will release the metals from the sediments to the water column. From this, management options to prevent release of these contaminants can be developed.

The Impact of Landfill Leachates on the Merri Creek

The Natural Resources and Environment Committee (1990), reporting on the state of waste management in Victoria, recognised the need for knowledge of the impacts that landfill sites have on the environment. Key points of their report were a lack of information on locations of disused sites and processes involved with leachate transportation.

This individual project on landfill leachate is designed to illuminate the situation in the Merri Catchment. A high priority has been to identify sites and then determine their likely impacts. Determining these impacts for all the landfills was considered to be beyond the scope of the project, so efforts have been concentrated at one site at Cooper Street, Campbellfield.

Other Research:

• Several field trips were undertaken to help identify the current state of the waterways, and to identify recommended sites for management actions, such as the establishment of wetlands. • The team took part in a platypus survey during the summer of 1994/5 to determine if platypus lived in the Merri Creek. The survey was undertaken by Australian Platypus Conservancy - a group who are monitoring the distribution of platypus in the Yarra catchment.

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1.6 Structure of this Report

This report is organised into four sections. The first section, on the Human Environment, examines how the human community interacts with the creek, how changes in human land use have impacted the waterways over the years, how the community perceives and values the creek, and how social systems, such as government agencies, political frameworks and community groups affect the creek. The second section concentrates on Geomorphology and Flow, for example the degree to which the natural channels of the creek have been modified. The third section focuses on the current state of knowledge about the Water Quality of the creek; physical and chemical parameters such as turbidity and temperature. The fourth section looks at the Aquatic Ecology of the waterways including the existing flora and fauna and how they interact.

15 Waterways of the Merri Catchment

1.7 A Journey down the Merri Creek

The Merri Creek is the arterial stream after which the Merri Catchment is named. A journey down the Merri Creek is probably the best way to introduce how the creek functions, the interactions that occur and the surrounding land uses and their associated problems. This journey could have been purely geographical but this investigation has tried to include some of the changes that have occurred over time in order to provide a more rounded picture of the Merri Creek. This excursion describes the main creek and its immediate surroundings only. Those who may be side-tracked by desires to explore the tributaries will have to do so by themselves.

The Merri Creek arises in the hills that form the Great Dividing Range near Heathcote Junction where a number of small streams converge. Dense vegetation originally covered the banks of these streams but the introductions of European settlers have changed this substantially. On these banks, introduced ground covers such as Kikuyu and Couchgrass grow in the shade of the remnant stands of Long-leaved Box, Red Stringybark and Black Wattle. The streams themselves have also been altered, by some on-stream dams and channel straightening. However they are still predominantly perennial with the very uppermost parts being ephemeral. These streams would have been home to some native fish species - perhaps including the Mountain Galaxias - that are no longer present.

As the Merri Creek descends and begins to traverse the basaltic plain at the foot of the hills around Wallan, its water velocity decreases markedly. Sediment deposited over a wide area forms a swampy alluvial floodplain. At the base of these hills the Merri Creek is joined by several tributary creeks including Wallan, Mittagong and Strathaird Creeks. These swampy areas used to hold considerable amounts of water during flood events but they have now been all but completely drained for use as pasture. Swamps remain between Green Hill and Mt Fraser (Hernes Swamp), at Beveridge and between Merriang Park and Merri Creek Park. A person visiting the Merri Creek as it flows past this spot would find a creek considerably altered by agricultural practices. Flows have been reduced by dams on the smaller tributaries so that there is negligible flow. Banks are almost completely devoid of overhanging vegetation and channels are straightened - providing little habitat for fish, reptiles, amphibians and waterbirds such as the Australian Bittern, the Rufous Night Heron, the Great Crested Grebe and the Royal Spoonbill. The draining of the swamps is particularly harmful to the waterbirds that breed there and the amphibians that can live no- where else. The plant communities in the remaining wetlands include Spike-rushes, Bulrushes and the Swamp Wallaby-Grass. Beyond the streambanks, there is relatively extensive remnants of the Floodplain Grassland (consisting of Common Tussock Grass and scattered River Red Gums) that would have originally covered much of the area. The water quality in this part of the creek is relatively good but may be quite high in nutrients (from farming practices) and salinity. The water may appear muddied from stock trampling of the banks - there is uncontrolled stock access along the length of the stream.

Around Merri Creek Park, the creek widens to 15 metres and meanders its way through pasture before being joined by Kalkallo Creek at Donnybrook. In its passage the creek skirts the line of dormant volcanic cones that run from Pretty Sally on the Great Dividing Range to Mt Ridley near Craigieburn. These volcanoes were last active between 2 million and 800,000 years ago and are the source of the basalt across which the creek flows. Travellers to this part of the creek would find it in a fairly natural state; although only of a low flow, the water is of good quality and only slightly turbid. The creek flows through

Page 2 State of the Environment Report - Introduction pools surrounded by reeds and banks that afford some shading from the isolated pockets of remnant River Red Gums and Silver Wattle. However, introduced plants such as Hawthorn and Boxthorn dominate the understorey. Keen wildlife observers may spot the rare Freshwater Blackfish and the Sacred Kingfisher in these parts while others may find the remains of the Wurundjeri occupation at the Donnybrook springs.

After its confluence with Kalkallo Creek, the Merri Creek enters the valley it has incised by erosion that extends all the way to its junction with the Yarra River. Before entering the outer Melbourne suburbs, the Merri Creek is joined at Craigieburn by Malcolm and Aitken creeks and a little lower down by an unnamed stream at O’Herns Road. These tributaries swell the creek considerably. Visitors to these reaches of the creek would find much about the appearance of the creek natural and attractive. The water flows sedately through long pools and over riffles. Common Reeds, Marsh Club-rushes and Tall Spike-rushes emerge from the water. The few kilometres up and downstream of Craigieburn are a good example of native Riparian Scrub. Narrow but continuous ribbons of dense scrubby Woolly Tea Tree, Sweet Bursaria and River Bottlebrush line the creek, overshadowed by River Red Gums and Silver Wattle. Elsewhere the sparse, mainly exotic vegetation offers little shade to the creek's inhabitants. Unsightly scarring from the quarry in Summer Hill and the closeness of the Hume Freeway spoils otherwise picturesque views in the mid-part of this section. Until Aitken Creek feeds the Merri Creek, the water quality is quite good being only slightly turbid and enriched in nutrients. However, treated Craigieburn sewage discharges into Aitken Creek a little way above the Merri Creek. The impact on the water quality is severe, substantially increasing the levels of nutrients and lowering the amount of oxygen dissolved in creek water. This is likely to be a barrier to movement of those fish such as the Freshwater Blackfish that require oxygenated waters.

The encroachment of the northern suburbs greatly affects the Merri Creek and this is first felt at Somerton where polluted runoff from industrial development degrades the water quality and riparian vegetation of the creek. The creek still flows through an incised channel but instead of being overlooked by a grassy plain, houses and factories dominate the scene. The northern part of the channel is predominantly natural but fairly extensive remodelling of the southern portion has destroyed much of the natural value. The stream flows through a series of riffles, runs, glides and pools till it reaches the Yarra River at Abbotsford. On the way it is joined by the major tributaries; Edgars Creek and Merlynston Creek. Coburg Lake, set between the confluences of these two tributaries, impedes the natural flow of the creek. The union of these waterways considerably swells the Merri Creek, which is by now a major stream at least 20 metres wide. The quality of the vegetation on the banks deteriorates on progression towards the city. Starting out as a reasonably wide corridor of a native and exotic mix, the vegetation cover narrows and becomes increasingly dominated by introduced species such as various types of Willow, Hawthorn, Fennel, Onionweed and Kikuyu. Because the creek runs through urban parkland for much of this section, the banks have often been cleared of vegetation to the water’s edge - giving no refuge for stream inhabitants. In other places, revegetation work has restored some of the former beauty but pollution sullies much of this.

Drains carrying polluted stormwater from roads and buildings begin to have a marked impact on water quality from Ainslie Road in Campbellfield. Litter is also a big problem in the urban environment and the creek captures much of this, being very visible either in the water or wrapped around tree branches. The combined effects of poor water quality, destroyed riparian vegetation and a modified channel make living in the stream very difficult. The community of macroinvertebrates, which form the basis of many larger animals’ diets, is severely reduced by these poor conditions - in comparison with the upper

Page 3 Waterways of the Merri Catchment reaches. Many native fish are intolerant to these forms of pollution leaving the creek available to the more tolerant species such as the introduced Carp and Mosquitofish. However, recent catches of Tupong, Flat-headed Gudgeon, Short-finned Eel and Broad- finned Galaxias show that there are some native fish that tolerate degraded waters. Many of the native fish are migratory and the barrier presented by the weir at Coburg Lake makes movement impossible. Platypus, once common here, are rarely seen now. This is probably due to a lack of suitable breeding habitat but the presence of dogs, cats and foxes may also play a part.

Having taken a trip down the Merri Creek, we can see how our lifestyle has effected it and how the creek has withstood these challenges. While severely degraded in some parts, there are many aspects of the creek that are worth preserving and re-establishing for, in many cases, there is much with and for which to work.

Page 4 State of the Environment Report - Introduction

Summary: The Human Environment

The human environment section of the report describes the main interactions between people and the waterways of the Merri Catchment. It describes the changes in land use, with the conversion of bushland to agricultural, industrial and residential land. However, these are not the only changes. Other changes include community perception of the Merri Creek and how we interact with it. This is reflected in changes in legislature, management and political objectives.

This report recognises that humans should not be considered separately from the environment as essentially they are part of the aquatic ecosystem. This separation is only used to assess human influences within the aquatic ecosystem and how this may alter the pre-European balance.

Pre-European uses of the Waterways of the Merri Catchment There is considerable evidence that the indigenous Wurundjeri people placed enormous value on the waterways. That is not to ignore the fact that they also had an impact on the waterways through fire regimes and hunting. However, human uses of and impacts on the waterways changed considerably in the period since European settlement. These differ in a vital respect from the Koori involvement with the Merri Creek and this difference is cultural.

Changes in human uses since settlement Early in the settlement history of Melbourne the Merri Creek provided industry with a source of water and a sink for the disposal of waste. This industry was largely confined to the inner suburban banks of the creek and grew outwards as the city grew. Agriculture was an important early use of the plains of the northern Melbourne region. As the population of Melbourne has grown, residential development in the northern suburbs has proceeded unfettered.

Agriculture Of the 400 km2 of catchment area, approximately three quarters is agricultural land, the majority of which is grazed land. Grazing has caused major changes to the natural environment, such as the clearing of native vegetation, loss of wetlands, channel modifications, increased nutrient input into streams and trampling of the riparian zone by cattle.

The record of LandCare groups in Victoria and elsewhere to halt land and water degradation is proven. There is no such group within the Merri Creek catchment at present and the establishment of one would greatly benefit the catchment.

Industrial Development The area of land currently used by industry represents about 5% of the total catchment. The majority of these sites are along the banks of Merri and Edgars Creeks between the rural and residential zones. Industrial development is an important source of water pollution and is continuing to cause a deterioration in the health of the aquatic ecosystem.

Several major types of heavy industry are based in the Merri Catchment. These are diverse and include the motor, metal processing, quarrying, construction, waste, food processing, textiles and petro-chemical industries.

Page 5 Waterways of the Merri Catchment

Light industry also plays a role in the business sector here. Pollutants from such industries may be significantly higher than those from residential areas in a number of parameters such as metals and nutrients.

Residential Development The present extent of urban development is approximately 67 km2 (representing nearly 17%) of the total catchment area. Residential planning projects further increases in the coming decades. The Merri is a designated “urban growth corridor”. Urban development poses a number of threats to the health of the waterways as outlined below.

Sewage Treatment in the Merri Catchment Sewage is a major contributor to high nutrient, suspended solids and E. coli levels in the Merri Catchment. The Craigieburn Sewage Treatment Plant has been discharging treated effluent to the Merri Creek since 1979. A recent upgrade of the Plant from secondary to partial tertiary has seen nutrient output levels fall. However, it is still a major contributor of nutrients and suspended solids. Plans are for the Plant to remain in operation indefinitely and expanded to twice its current capacity early in the next century. It is hoped that a major part of the effluent will be discharged to land.

Septic tank effluent leakage from unsewered properties is recognised as a source of water pollution in certain areas. Sewage contamination of stormwater from Emergency Relief System discharges occurs when stormwater, illegally connected to sewer, puts excessive pressure on the system. The system is “relieved” by discharge to stormwater drains. From time to time problems arise from unlicensed discharges of sewage direct to water.

Stormwater in the Merri Catchment The large impact of urban stormwater on the health of waterways has only recently been recognised. While large point source pollution from sewerage and industry has become better managed over the past two decades, the problem of diffuse source pollutants from stormwater runoff is more difficult to address. These pollutants include nutrients from detergents, oils and heavy metals from road surfaces, and pathogens from animal faeces. The large volumes of runoff also cause erosion and flood problems within the waterways.

Community attitudes to and uses of the waterways Recent studies indicate that the local community highly values the natural environmental features of the waterways of the Merri Catchment. The major concerns that people have expressed about the creek in recent surveys are litter, pollution and poor water quality. As a result of these concerns, the community regards enhancement of the natural environment as a high priority.

Current agency and institutional influence in the Merri Catchment Other than the Merri Creek Management Committee, who undoubtably have a big influence in the short to medium term (at least in the urban catchment), major stakeholders are the local governments, Melbourne Water Corporation, Parks Victoria (ex Melbourne Parks & Waterways) and the EPA.

The local governments are directly involved with park management and indirectly through representation on the MCMC board of directors. All relevant councils (except the Shire of Mitchell) are involved in this manner.

Page 6 State of the Environment Report - Introduction

Melbourne Water Corporation (MWC) is responsible for major stream works related to flood mitigation and main stormwater and sewer drain maintenance. They have two members on the MCMC board of directors and provide some funding.

Parks Victoria (Melbourne Parks & Waterways (MPW) provides grants funding for discrete projects to the MCMC. This agency owns significant parcels of land within the catchment.

Environment Protection Authority (EPA) has a major role to play in the Merri Catchment by way of the SEPPs and Licences to Discharge Waste. Data from the Victorian Water Quality Monitoring Network is distributed to the EPA to enable enforcement of the licences and bring the water quality in line with the SEPP guidelines.

Yarra Valley Water (YVW) has taken over the responsibility for many of the water supply and sewage responsibilities in the catchment since the division of Melbourne Water in 1995. It is now manages the Craigieburn Sewage Treatment Plant and many of the sewer Emergency Relief Systems in the catchment.

Current policies that have influence in the Merri Catchment State Environment Protection Policy (SEPP) is the main legislation affecting the waterways of the Merri Catchment. The Merri Catchment is currently protected by two SEPPs; Waters of Victoria; and Waters of the Yarra River and Tributaries. The Yarra SEPP was developed for the Yarra catchment in 1984 and sets the benchmark to which all activities affecting the aquatic environment. All EPA licences and works approvals must be consistent with this policy. This policy is currently being updated and will become a Schedule to the statewide policy (Wates of Victoria). A draft for public comment was released in December 1995 and should be finalised by 1997.

Licences to discharge waste to water A number of premises are licensed by the EPA to discharge waste to water. Four licences are granted to Extractive Industries which discharge contaminated stormwater containing sediments and salts, and some trace contaminants such as nutrients, petroleum products, oils and heavy metals. Ten licences for sewage and sullage discharges are granted. There is also one licence to discharge wastewater of elevated temperature and containing trace contaminants of heavy metals (zinc, iron and chromium). Compliance with these licence conditions has not always been satisfactory.

Conclusions Many of the problems in the waterways of the Merri Catchment result from human activities in the catchment. These problems generally result from poor management of such activities to limit the impact on the waterways, and there are many opportunities to reduce these impacts at the source. This reduction can be achieved by the use of best available practices in the catchment for urban design, sewage disposal, stormwater management and litter and waste management.

Page 7 Waterways of the Merri Catchment

Page 8 State of the Environment Report - Introduction

2. The Human Environment

2.1 Introduction

This section examines how the human community interacts with the creek; how changes in human land use have impacted the waterways over the years, how the community perceives and values the creek, and how social systems, such as government agencies, political frameworks and community groups affect the creek.

2.1.1 Previous work

A few studies have been carried out on various aspects of the human interactions with the environment of the Merri Catchment and are outlined below. However, most information for this section has been gathered through consultations with various agency staff.

Johnson & Ellender (1993) study. This was a study of the pre-European inhabitants of the Merri Creek area.

The Public Interest Research Group (1975) study. This group reported on many aspects of the social and cultural environment and has formed the basis of many studies since.

Context Pty Ltd and Loder & Bayley Consulting (1993) study. This group studied aspects of recreation and access to the creek to assist in the development of the Merri Creek Concept Plan.

2.2 Natural (pre-European) uses of the creek

History in the Melbourne area - as most of us know it - began in 1835 when John Batman sailed up what was later named Port Phillip Bay. In June of that year, Batman “bought” a vast tract of land that stretched from Geelong to the Merri Creek from the native Koori people that occupied Melbourne and its surrounds - even at this early stage the Merri Creek represented a boundary between states of control (PIRG, 1975). However, as we have come to realise, there is a history prior to European settlement and this is constantly being rediscovered.

When Batman arrived, there were probably about 300 Koori people mainly from the Wurundjeri clan in the Melbourne area (PIRG, 1975). The clan that occupied the land from the Maribyrnong River to Darebin Creek are known as the Wurundjeri willam.

Most of this Koori tribe was either killed in conflict with the new settlers or by disease. Those that survived were forcibly removed from their traditional lands to other parts of the state or into Christian missions (Wigney, 1994). Although today there are surviving descendants of the Wurundjeri willam, the way in which they used the Merri Creek is not fully understood. Conventionally, the evidence accepted was that provided either by archaeological means or by observation and documentation by reputable people. More

Page 9 Waterways of the Merri Catchment

recently we have come to recognise the value of oral histories handed down from generation to generation of Wurundjeri people.

A number of archaeological sites have been identified along the Merri Creek (Johnston, C. & Ellender, I., 1993) and from these sites we can gain an insight into the relationship the Wurundjeri people had with the creek. River Red Gums (Eucalyptus camaldulensis) that grow along the banks of the Merri Creek bear testimony to Koori shield and canoe- making practices. Few examples of these trees remain, however a few are still growing near Cooper St, Campbellfield (Wigney, 1994).

Archaeological investigations and recorded observations by the early European inhabitants reveal a number of places used as gathering or meeting places and camping sites (PIRG, 1975). Dights Falls at the confluence of the Merri Creek and the Yarra River and Ruckers Hill, Northcote overlooking the Merri were chosen meeting places for tribes from all over Victoria gathering for ceremonial occasions. Dights Falls was the site of a camping ground for approximately 90 people in the 1840s.

Further up the creek, the springs at Donnybrook attracted Koori people to the area just as it attracts people today. Johnston & Ellender (1993) provides an overview of the sites identified to date.

In general, Johnston & Ellender (1993) recommend that a number of landforms associated with the Merri Creek were important to Aboriginal people and therefore are archaeologically sensitive; these include: • river terraces • a flat top of the escarpment overlooking the creek • residues of ancient swamps • volcanic vents of Bald Hill, Mt Fraser and others • the exposed interface between basalt and the underlying sedimentary rocks • stands of old Red Gum woodlands • rock overhangs with soil floors within the basaltic cliffs in deeply incised parts of the valley

As alluded to above, the community is beginning to appreciate the value of the remaining strands of Koori heritage, through a recognition of their oral traditions and spiritual beliefs. In the Merri Creek region, this oral tradition is represented by some knowledge of the plants and animals used by the Wurundjeri people for sustenance and service. Edible aquatic plants include the Marsh Club-rush (Bolboschoenus medianus), Common Spike-rush (Eleocharis acuta) and Water-ribbon (Triglochin procera) all of which have tubers that can be eaten raw or baked (Wigney (ed.), 1994). Animals such as fish, eels, yabbies, frogs and freshwater mussels were also an integral part of their diet (Wigney, 1994).

Page 10 State of the Environment Report - Introduction

Box 1 Impacts of Agriculture on Waterways

The major impacts of agricultural activity on water quality are:

1. Clearance of native vegetation

Native vegetation is well adapted to the Australian environment and acts to protect the land from the impacts of rain and runoff. Clearance of this vegetation may result in:

• Erosion leading to increase sediment runoff and turbidity • Increased transport of nutrients to streams • Increased salinity, due to a rise in the water table (groundwater level)

2. Changes to wetland hydrology

Alteration to natural watercourses and swampy wetlands by straightening or draining for the purposes of increased pastoral land has a significant impact on ecosystem health. These changes also reduce the water-holding capacity of these upper-catchment areas. The downstream effects of this are disastrous in terms of flooding.

3. Toxicants (pesticides, herbicides)

Agricultural chemicals can reach rivers as wind blown sprays (spray drift), leaching and surface runoff, where they affect the water quality. The extent of toxicant transport depends on the rate and frequency of application, the nature of the soils and the physical properties of the toxicant.

4. Nutrients (fertilisers)

Agriculture is an important source of aquatic nutrients from potassium, nitrogen and phosphorus-based fertilisers. Like toxicants, they can reach streams through spray drift, leaching and surface runoff. These raised nutrient levels encourage plant growth, especially algae, causing eutrophication. Impurities in fertilisers, such as heavy metals are also believed to concentrate in soils and sediments over time and concentrate in organisms by the process known as bioaccumulation.

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2.2 Changes in Human Use since Settlement

2.2.1 Introduction

The change in human use of the Merri Catchment since European colonisation is the most fundamental cause of degradation of the natural environment. Land clearance for agriculture and industrial and urban development (shown on Map 2) has dramatically altered the physical environment, and contributed to the pollution and degradation of the waterways of the Merri Creek catchment. While it is relatively easy to identify the factors that are contributing to the decline of the aquatic ecosystem, determining the sources of pollution is a difficult task.

From its headwaters in the foothills of the Great Dividing Range near Wallan, the Merri Creek and its tributaries pass through three main types of land use; agricultural, industrial and urban, before joining the Yarra River in Clifton Hill. The waterways are affected, to varying extents, by the human activities taking place in these different areas, each of which play a part in determining the state of the creek and the level of pollution of the aquatic ecosystem. It is the cumulative effect of many - individually small - deleterious actions within the catchment that has radically altered the natural state of the Merri.

In the following sections, the contribution to aquatic pollution from these three main land use areas will be discussed, at first in general terms and then more specifically as they relate to the Merri Catchment.

2.2.2 Agriculture

Agriculture in Victoria remains as the major cause of the decline in quality of the State's aquatic environment (OCE, 1988), and since a large portion of the Merri Creek passes through areas of rural land use (around 310 km2) it is clearly of some significance to the water quality of the Merri Creek.

The major type of agriculture within the Merri Catchment is grazing. Grazing has caused a major change to Victoria’s natural environment as a result of the clearing of native vegetation and its replacement by 'improved pastures' of high yielding introduced species reliant on the application of herbicides and pesticides.

Water runoff from agricultural land washes these chemicals into streams and rivers, where they have a significant impact. Other material such as nutrients from fertilisers, and soils from eroded land are also washed into the waterways. Water quality may also be degraded by stock trampling the riparian vegetation and stirring up the stream sediments. Stock faeces may increase the level of potentially harmful bacteria in the stream along with increasing the nutrient levels.

While initiatives such as LandCare are generally improving land use practises in many rural areas elsewhere in the State, there is currently no such group within the Merri Catchment.

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Map 2 Land-use types in the Merri Catchment

Page 13 Waterways of the Merri Catchment

2.2.3 Industrialisation

Industrial activity has historically developed beside water bodies which provided a source of water and a sink for the disposal of industrial waste. In the early days of the settlement of Melbourne, much of the pollution of the Yarra River and its tributaries (including the Merri Creek) was a result of such industrial activity and by the late 19th century Melbourne's waterways were severely polluted. In 1881, the Health Committee of the City Council noted that the Merri Creek was being polluted by an abattoir, from which 'an extensive accumulation of blood, offal and manure' was being discarded such that it would be washed into the creek by the next rains (OCE, 1988).

Today, many industrial areas still exist along the Merri Creek and a large section (approximately 20 km2 or 5% of the total catchment) of the northern suburbs alongside the middle segments of the creek is zoned for industrial use. Through the development of the sewerage system, better waste disposal techniques and more stringent laws, the water quality of Melbourne's urban waterways has gradually improved over the past century. However, industrial development is still an important source of water pollution and is continuing to cause a deterioration in the health of aquatic ecosystems. While abattoirs may no longer be polluting the banks of the Merri Creek, the expansion of modern industry and the more insidious nature of pollution may make further clean-up a more difficult task.

According to an EPA report, approximately 83% of industrial waste in the Yarra catchment is now discharged to sewer, however another 13.5% (mostly of cooling water) is discharged to drains which flow directly into our river systems (Robins, 1994a). A 1982 study of urban stormwater runoff in Melbourne (Weeks, 1982) showed that pollutants from light industrial areas were significantly higher than those from residential areas for a number of parameters such as metals and nutrients.

The major types of industry in the Merri Catchment are:

• Motor industry/Transport (eg. Ford, South Pacific Tyres, small scale automotive industry, Safeway distributions centre) • Metal processing (eg. Alcan, Tubemakers Australia) • Quarrying (eg. various Boral quarries) • Construction (eg. Boral bricks, Rocla Pipes) • Waste Disposal (eg. Epping Trade Waste Disposal, City of Whittlesea Tip) • Food Processing (eg. Nestles, Rowntree Hoadley) • Textile, Clothing and Footwear (eg. Australian Consolidated Hosiery) • Petro-chemical (eg. Mobil Oil Australia, Kodak Australasia P/L)

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Box 2 Impacts of Industrial Activity on Waterways

Turbidity: Certain types of industrial effluent contain high levels of suspended solids, which increase stream turbidity.

Thermal pollution: Discharge of heated wastewater increases the temperature of streams. Increased temperature decreases the water oxygen content, and provides suitable conditions for algal blooms.

Nutrients: Food processing and agricultural industries produce nutrient rich effluent. pH: Industrial effluent can alter the acidity or alkalinity of streams.

Heavy metals: Metal trades and petro-chemical industries produce wastes that contain heavy metals such as arsenic, cadmium, chromium, copper, lead, mercury and zinc. Sewage treatment works are often not able to treat such wastes and they are released to the aquatic environment where they are toxic to aquatic life and accumulate with time in the stream sediments.

While it is now an EPA requirement that most industrial waste be treated before being discharged to the sewage system, some industrial waste still reaches the aquatic environment from a number of sources, both from point source and diffuse (non-point) sources. Such sources include:

Point sources: • Legal direct discharges to water bodies • Discharges of effluent containing industrial wastes • Accidental discharges • Illegal dumping

Non point sources: • Air pollution • Overland runoff • Stormwater

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2.2.4 Urbanisation

From the study of the most recent maps (Melway, 1994) it is apparent that the extent of urban development at present is approximately 67 km2 (nearly 17% of the total catchment area) and is projected to increase further in the coming decades.

Box 3 Impacts of Urbanisation on Waterways

Increasing population and industrial activity generally leads to:

• Substantial catchment modification by the development of densely settled areas. • Use of surface waters for waste disposal • Use of rivers as resources for water needs. • Increased pressure on water bodies and their environs to meet recreational and aesthetic needs. (OCE, 1988)

However, an increase in population within a catchment does not necessarily result in an increase in aquatic pollution. Many factors influence the impact of urbanisation on aquatic environments. Factors such as whether sewage is discharged to water directly, the level of treatment before release, and the changing habits of water use and disposal in the community all affect the level of degradation or preservation of the aquatic ecosystem within urban catchments.

The main impact of urbanisation on water quality relates to the use of the water body as a sink for waste disposal (sewage) and as a drain for urban stormwater and both these impacts are substantial within the Merri Creek catchment.

Sewage Treatment in the Merri Catchment

The water quality of the urban section of the Merri Creek seems to have improved significantly over the past century. Early industrial activity, such as abattoirs on the banks of the Merri Creek resulted in the waterways becoming extremely polluted. In recent times, many efforts have been made to reduce the impact of sewage disposal on the State's waterways. However, a number of problems still exist in the Merri Catchment, including unsewered properties, sewer leaks and direct discharges to water of the Craigieburn Sewage Treatment Plant.

Craigieburn sewage treatment plant

There are three standards of sewage treatment in Victoria. Primary treatment involves the mechanical screening of solids and the sedimentation of solid matter. Secondary treatment involves the biological reduction of organic matter in the primary effluent.

Page 16 State of the Environment Report - Introduction

Tertiary treatment involves the reduction of nutrients (carbon, nitrogen and phosphorus) in the secondary effluent.

In Victoria, the State Environment Protection Policy for the Waters of Victoria requires sewage discharges to water to receive secondary treatment before being released to the aquatic environment, and establishes that wherever possible sewage should be discharged to land.

The Craigieburn Sewage Treatment Plant (Craigieburn STP) was established in 1979 to treat and dispose of the sewage from the newly urbanised area of Craigieburn. Until recently, it undertook secondary sewage treatment before disposing of secondary effluent into the Merri Creek. This has recently been upgraded to partial tertiary treatment, with the removal of phosphorus from the effluent. While secondary treatment of effluent reduces levels of the biological oxygen demand (BOD), and does not therefore deoxygenate the creek to the same extent that raw sewage would, it still has high levels of nutrients which have substantial impacts on water quality. The extent to which phosphorus removal has improved the water quality is not yet evident. A recent study of the Merri Creek indicates that the Craigieburn STP is still the significant source of nutrients in the catchment (Merrick, pers. comm.).

There was an amendment to the EPA waste discharge licence for the Craigieburn STP on 30 September 1993. The standards of the discharges to water for this amended licence are listed in Table 1 below:

Table 1 EPA Water Discharge Standard for Craigieburn STP as from September 1993 Indicator Unit Discharge Standards Median 90th percentile Maximum Biochemical mg/L 10 20 - Oxygen Demand Suspended mg/L 15 30 - Solids E. coli orgs/100mL 200 1,000 - Total Residual mg/L - - 1.0 Chlorine Ammonia mg/L 5 - 15 nitrogen Total mg/L 2.0 - - Phosphorus * Flow kL/day 3,000 - 11,000 * Higher phosphorus standards came into effect on 1 December 1993

Historically, the main area of non-compliance at Craigieburn STP has been phosphorus and E. coli. All Yarra Valley Water licences have been recently amended for a uniform condition of 10-10-10-1 standard (10 mg/L total suspended solid, biological oxygen demand & total nitrogen and 1 mg/L phosphorus). This is not apparent from the most recent licence for the Craigieburn STP.

Page 17 Waterways of the Merri Catchment

It is possible that a mixing zone will apply to the Merri Creek downstream of the treatment plant, the length of which is not yet defined. Yarra Valley Water will need to apply to the EPA for approval of this mixing zone under the provisions of the updated SEPP for the Yarra catchment. (Note: A mixing zone is an area in the receiving waters below an effluent discharge where assimilation of effluent takes place and certain environmental values/beneficial uses are not protected. Where possible, the use of these zones should be limited, ANZECC, 1992).

While the Craigieburn STP was originally only a short term measure until the completion of the North Western Trunk Sewer, it now appears that it will remain in operation indefinitely and will be expanded to twice its current capacity to deal with the increase in urban development in the region. Yarra Valley Water has recently (June 1996) completed a Waste Management Plan for Craigieburn. This includes an action plan to reduce impacts and minimise waste, and a Wastewater Re-use Feasability Study.

Unsewered properties

As the growth of urban areas has previously preceded the necessary infrastructure, many properties remained unsewered for some time, and such properties still exist in certain areas. For such properties, individual sewage treatment facilities are required, and this is usually a septic tank. While a small number of septic tanks are unlikely to have much impact on water quality, septic tank effluent is recognised as a source of water pollution, especially when many tanks are concentrated in one area.

According to Yarra Valley Water, there are 60 000 residential properties connected to sewer in the Merri Creek catchment, with 16 800 additional residential properties proposed by the year 2011. Yarra Valley Water has a Sewer Backlog Program which aims to service 230 currently unsewered industrial lots over the next 10-15 years.

Sewer spills

Emergency Relief Systems, i.e. systems in place that allow sewage to be discharged to stormwater drains when the pressures in the sewer demands release, have been improved recently. For the Merlynston Sewer, there has been a reduction in volume from 56 megalitres in 1992/93 to 20 megalitres in 1993/94 and for Edgars Creek, from 31 to 28 for the same periods. The improvements reflect improvements to the hydraulic capacity and more favourable weather conditions (Melbourne Parks & Waterways, 1995).

Stormwater treatment in the Merri Catchment

The importance of urban stormwater on the health of urban streams historically has not been adequately considered; partly because of the difficultly in dealing with such widespread pollution sources. Urbanisation increases the volume of stormwater runoff, while the quality of this runoff decreases considerably.

Stormwater is a “diffuse source” of pollution, that includes contaminants such as high nutrient-containing detergents from street car-washing, bacteria from animal faeces, vegetation, litter and heavy metals, oil and grease from roads. The increasing volume of

Page 18 State of the Environment Report - Introduction water that flows off impervious urban areas also causes erosion and increase turbidity in streams. A study by Weeks (1982) indicated that the level of biological pollution from urban stormwater could be comparable to secondary treated effluent from the same population. A summary of the key pollutants are presented in Table 2.

Table 2 Summary of Key Pollutants from Human Activities

Possible sources of pollution in the Merri Catchment and their effects on water quality are listed below.

Source of pollution in the Merri Key pollutants/impacts

Agricultural runoff • Nutrients • Organic pollution • Metal (arsenic) Craigieburn Sewage Treatment Plant • Nutrients

Municipal tips • Heavy Metals • Hydrocarbons Drains from industrial area • Heavy Metals In particular: • Oils (Hydrocarbons) - Ainslie Road drain • Nutrients - Coopers Road drain • Suspended solids - Somerset Road drain • Turbidity - Campbellfield Creek & Fawkner E • Salinity - Merlynston Creek • Elevated pH/temperature - Central Creek • low dissolved oxygen Unsewered properties • Organic pollution Urban Stormwater runoff • Suspended solids • Organic pollution • Nutrients • Heavy Metals • Oils (Hydrocarbons) • Increasing flows/erosion Groundwater • Salinity

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2.3 Current Community Attitudes and Uses

Community attitudes towards the Merri Creek and its surrounding parklands have been surveyed in the past few years during the compilation of the Concept Plan (see Community Consultation Report by Diversity Coalition Inc. & Context Pty Ltd, 1993; Customer research: Survey of Local Residents Report by Jan Bruce & Assoc. Pty Ltd, 1993). This section summarises the parts of these reports that relate to the aquatic environment of the Merri Creek. Box 4 shows the responses to the questions.

The Merri Creek and its surrounding parkland currently provides an opportunity for walking, bike-riding and other activities that use the open space and natural environment. Considering the information in the two community consultation reports of the Merri Creek Concept Plan, the features of the Merri Creek that are most appreciated by the local community are natural features of the environment, such as the trees, the wildlife and the water. It is not too surprising that the main areas requiring improvement expressed by the community are those that will enhance the natural environment of the Merri Creek. In particular, factors which are detrimental to the natural features of the creek, such as litter, pollution and poor water quality are areas of major concern. Likewise, actions that improve the current state of the natural environment, such as more native vegetation and wildlife are also high priorities.

Several activities which also require the enhancement of the creek, such as fishing and swimming were not major priorities set by the community. While many people may support the vast improvement in water quality needed to enable safe swimming and fishing for edible fish in the waterways of the Merri Catchment, they do not appear to support the improvement of the water quality for these activities, but perhaps for the general improvement of the natural environment that it would provide.

The small percentage (<1%) of the community that supported the restoration of the Merri Creek corridor was surprising. The significance of this response is unclear, since it is not explained what is meant by the term 'restoration' in this sense. Given the support for the improvement of many of the natural features of the Merri Creek, such as native vegetation, better water quality and more wildlife, it would appear that some degree of restoration is a high priority for the community. If 'restoration' implies the absolute return of the creek to its pre-European state, without walking and bike tracks and especially without non-aboriginal people, then this response is not so surprising.

The Merri Creek Management Committee has run, and continues to run, a number of community education programs aimed at increasing the awareness of environmental issues of the community in general and shop traders in particular (Lawrie, pers. comm.). Particular projects include; Drains to the Merri, in which a Platypus is painted on drain inlets in order to draw attention to stormwater movements and their effects. Another project has been with Sydney Road Traders to try to limit the litter emanating from their stores.

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Box 4 Community Consultation Report

From October to December 1992, the local community of the Merri Creek were surveyed to determine their attitudes towards the existing Merri Creek parklands, how they currently use the parklands and their preferences for future development. The report concentrated specifically on the attitudes of the young (both primary and secondary school students), those from non-English speaking backgrounds and community and special interest groups.

The main community uses of the creek and surrounding parkland was assessed by asking:

1. How do you spend your time at the Merri Creek?

The main (>10%) responses and the percentage of the total response were :

Walking ...... 38% Bike riding...... 17% Having fun/informal games. 16% Relaxing...... 10%

Other responses directly relevant to the waterways were:

Exploring/observing nature.9% Fishing ...... 3% Water: playing/swimming....2 % Boating/canoeing...... 1%

2. What features of the Merri Creek do you enjoy?

The main (>10%) responses and the percentage of the total response were:

Trees...... 22 % Nature/animal/birds ...... 19% Water ...... 17%

Other responses directly relevant to the waterways were:

Running water...... 2% Environment...... 2% Swimming ...... <1% continued next page...

Page 21 Waterways of the Merri Catchment

3. What features of the Merri Creek need improving?

The main (>10%) responses and the percentage of the total response were:

Water quality...... 27% Vegetation/trees...... 23% Litter problem...... 22% Rubbish dumping...... 16% Pollution ...... 10%

Other responses directly relevant to the waterways were:

Nature ...... 4% Weeds...... 2% Swimming ...... 1% Erosion...... 1% Fishing ...... <1% Restoration ...... <1%

4. What would be the ideal appearance of Merri Creek parklands in 20 year's time?

The main (>10%) responses and the percentage of the total response were:

Cleaner ...... 42% More vegetation (native).....34% More wildlife...... 13%

Other responses directly relevant to the waterways were:

Opportunities for fishing...... 4% Opportunities for swimming 3%

(All data from Diversity Coalition Inc. & Context Pty Ltd, 1993)

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2.4 Agencies and Institutions

2.4.1 The Players

The agency with most political interest in activities concerning the waterways of the Merri Catchment is the Merri Creek Management Committee; there is, however, a complex web of institutions and structures that appear on the political map all of which have some degree of influence over activities within the Merri Catchment. This section introduces these agencies; the legislation, strategies and other instruments through which they act are discussed in Statutory Objectives.

Community sphere

• Friends of Merri Creek • Friends of Merri Merri Park • The residential community • The business community

Local Government sphere

• City of Moreland • City of Darebin • City of Hume • City of Whittlesea • City of Yarra • Shire of Mitchell

State Government sphere

• Melbourne Water Corporation (MWC) • Parks Victoria (PV) (ex Melbourne Parks and Waterways MPW) • Yarra Valley Water (YVW) • Environmental Protection Authority (EPA) • Department of Natural Resource & Environment (DNRE) • StreamWatch • Port Phillip Catchment and Land Protection Board • YarraCare

Federal Government sphere

• Department of the Environment • Commonwealth Environment Protection Authority (CEPA) • Environment Australia (ex Australian Nature Conservation Agency ANCA) • Councilnet • Environment and Resource Information Network (ERIN) • Save the Bush • LandCare Australia • Greening Australia (Victoria) Ltd

Page 23 Waterways of the Merri Catchment

Community Sphere

The Merri Creek Management Committee is controlled by a board of 18 directors who consist of two places for each of the five member councils, two representatives from Melbourne Water Corporation, and six community representatives from the Friends of Merri Creek.

The Friends of Merri Creek were formed in 1988 and have a broad interest in many aspects of the Merri Creek environment. The Friends have been and still are the most influential community group in the catchment. Who are they and who do they represent? To be a “friend of Merri Creek” one does not need to live in the catchment but the majority of members do and use the creek parklands regularly. The people who are active in this community are, to broadly categorise them, from a more affluent and better educated background than the majority of the residents in the catchment. A high proportion of the members live in the inner portion of the urbanised catchment. This is in accordance with the respondents to the recent survey of people interested in the Merri Creek (Jan Bruce & Assoc., 1993). The demographics of these people interested in creek matters is different to the average for Melbourne. The survey revealed that the people most concerned for the welfare of the creek were well educated (53% of respondents had tertiary education). There is also an above average representation of cultures other than Australian.

There are even more “local” community organisations with quite specific interests and the Friends of Merri Merri Park is one such group. These local groups are encouraged by the larger Friends of Merri Creek.

It is worth noting that there are no organised rural community groups in the catchment such as a LandCare or StreamWatch group. This may mean that rural problems are being ignored in favour of more “obvious” urban ones; “the squeaky wheel gets the oil”. This may mean that important rural problems go on unaddressed but also affect the downstream portion of the catchment to the detriment of the community living there.

Discussions with a local resident in the Craigieburn area revealed that a LandCare group was tried in the area but it received no support from the DNRE. An extension officer for the Melbourne region was not allocated to this area and the opportunity was missed. The retired Victorian President of the National Farmers Federation, Roger Mason, lives in the area and has tried to get it “up and running” but received no departmental support.

The Community is more likely to engage in these sorts of activities if they perceive that they (their lifestyles) are under threat. For example, they are more likely to do something about the problem of needle grass if they could be made aware that their cattle will not eat it and therefore their pasture will eventually become unproductive. If landowners currently want to become involved they would probably use the Whittlesea Agricultural Society or the Plenty Valley Conservation Society.

Local Government sphere

Six councils run municipal affairs in the Merri Catchment (Map 3) and each gives the Merri Creek varying amounts of attention. Each council has a conservation/environmental officer who contributes in some way to the Merri Creek. At present there is a deal of uncertainty within each council as to tenure, and a high turnover

Page 24 State of the Environment Report - Introduction of staff has led to the loss of knowledge and informal communication networks. This loss has the effect of making each municipality a little more insular. Another factor is the Compulsory Competitive Tendering process that each council is forced to adopt. This process will probably have some long-term benefits for the creek. In the short-term, however, it means that services previously carried out by one part of the organisation now may be out-sourced to a number of different private firms causing a less unified approach to waterway management. The Merri Creek Management Committee was, before amalgamation, working closely with all these councils except the Shire of Kilmore. The MCMC now works with all the new councils except the Shire of Mitchell and has representation of each of these councils (two places per council) on the MCMC board.

State Government Sphere

The Department of Natural Resources and the Environment is the body to which a number of agencies (listed below) report. The Department resigned its place on the MCMC board in 1995. The department also has a number of branches which are able to provide technical advice and support:

• Office of Water Reform; develops water management policy. It has funded wetland investigations and has some expertise in this area. • Flora and Fauna Guarantee; officers are able to provide advice and management plans for landowners who have endangered species on their properties. • Flora and Fauna Branch; undertakes wildlife research and management options. • Land for Wildlife Scheme; joint operation with the Bird Observers Club and provides management advice for landholders (in the form of Extension Officers).

Page 25 Waterways of the Merri Catchment

Map 3 Merri Creek Catchment and Municipal Boundaries

Page 26 State of the Environment Report - Introduction

Melbourne Water Corporation (MWC) is responsible for major works along the creeks mainly related to flood mitigation as is the maintenance of the main stormwater drains. They also collect water quality data (on behalf of the EPA) and streamflow data. They currently have one representative on the Merri Creek Management Committee board. Recently Melbourne Water has divested itself of its water supply arm, splitting this responsibility into three corporatised bodies for future privatisation; Yarra Valley Water and City West Water each control parts of the Merri Catchment. There appears to be opportunity for further privatisation of services. They come under the umbrella of the Department of Natural Resources and the Environment. Melbourne Water sometimes funds part of the Merri Creek Management Committee’s manager’s salary.

Melbourne Parks & Waterways (MPW) is responsible for managing the major metropolitan parks. In the Merri Creek they provide project funding for revegetation works. The Merri Creek receives part of the $100 000 allocated to councils for restoring bike paths, etc. Like MWC, MPW comes under the umbrella of the Department of Natural Resources and the Environment.

Environment Protection Authority (Victoria) is the main body responsible for ensuring environmental protection in Victoria. The organisation creates State Environment Protection Policies, which set objectives for environmental standards for which beneficial uses of the environment are protected.

YarraCare is a community-based program aimed at identifying and managing catchment-wide land and waterway issues. The program involves all the key government agencies listed above and many community representatives.

Port Phillip Bay Catchment and Land Protection Board co-ordinates catchment management in the Melbourne region.

National sphere

The Commonwealth Department of the Environment (DEST) is the Federal Government department responsible for many of the environmental conservation groups that operate across Australia. It is also the department to which the Commonwealth Environment Protection Authority and the Australian Nature Conservation Agency report.

Commonwealth Environment Protection Authority (CEPA) takes a leading role in co- ordinating the various state EPAs and administers specific Commonwealth Acts including the Environment Protection (Impact of Proposals) Act (1974).

Australian Nature Conservation Agency (ANCA) is the Commonwealth body responsible for administering programs such as Save the Bush and One Billion Trees under the umbrella of the National Landcare Program.

Page 27 Waterways of the Merri Catchment

Networks and programs developed by DEST and ANCA

Councilnet is an electronic network designed to provide environmental information and facilitate communication for local government

ERIN (Environment and Resource Information Network) is a network for the provision of support for the Save the Bush and One Billion Trees programs. Part of this is a national environment biological database.

Save the Bush is a program developed to retain the remnant native vegetation throughout Australia. ANCA partially funds the program and over half this money goes directly to the community, local government and educational institutions. Projects such as brochure publication and sign construction and surveys of flora and fauna within local ecosystems have been funded in the past.

LandCare is a network of community organisations committed to restoring Australia’s vegetation resources. The groups try to co-ordinate work on a catchment-wide basis. Traditionally rural in outlook, they have been concerned with issues such as salinity, soil structure decline, soil acidity, weed invasion and pest species and stream erosion. Some LandCare groups are involved in monitoring activities such as Saltwatch.

Waterwatch is an education and awareness program co-ordinated by ANCA. This initiative fosters community-based water quality monitoring programs.

Other networks and organisations

Nexus is an electronic network that links educational institutions across Australia. It provides access for students to a range of current information about the environment.

Greening Australia (Victoria) is a non-profit community organisation committed to protecting and restoring local native vegetation. It receives Federal Government funding through the One Billion Trees program. In Victoria it receives State Government grants and private sponsorship. It allocates money, through its projects, to community-based schemes.

Page 28 State of the Environment Report - Introduction

2.5 Legislation, Strategies and Policies

A number of different pieces of legislation and strategic direction have an influence in controlling actions within the Merri Catchment. These exist at all levels, from international conventions to State Government policy. This section outlines the main instruments that relate to the waterways of the Merri Catchment.

The most important piece of legislation controlling water quality in the waterways of the Merri Creek catchment is a state act, the Environment Protection Act (1970). The implications of this act on the Merri Catchment are outlined in some detail before turning to other pieces of relevant legislation.

2.5.1 The Environment Protection Act 1970 (Vic.)

The Environment Protection Act (1970) established the Environment Protection Authority and outlines its responsibilities and powers for the protection of the environment. Through the development of State environmental policy, it aims to protect the main beneficial uses of the environment by managing waste discharges, preventing pollution, and protecting and improving environmental quality.

Regarding water quality, the Environment Protection Policy has a number of strategies for environmental protection, in particular State Environment Protection Policies (see Box 5 for background) and licences to discharge waste to water.

Box 5 State environment protection policy

The State environment protection policy (SEPP) establishes the "basis for maintaining environmental quality sufficient to protect existing and anticipated beneficial uses" for a particular area, and specifies:

• Boundaries of the area affected • Identification of the beneficial uses to be protected • Selection of environmental indicators to be employed to measure and define the environmental quality • A statement of environmental quality objectives • The program by which the stated environmental quality objectives are attained and maintained

The SEPP is the benchmark on which all activities affecting the aquatic environment are compared and all EPA licences and works approvals must be consistent with it.

Page 29 Waterways of the Merri Catchment

State environment protection policies (SEPPs)

The three policies that specifically concern the Merri Catchment are outlined in Box 6.

Box 6 SEPPs affecting the Merri Catchment

SEPP (Waters of the Yarra River and Tributaries)

This is the main policy controlling the water quality of the Merri Creek and its tributaries. The Yarra SEPP was developed for the Yarra catchment in 1984 and sets the benchmark to which all activities affecting the aquatic environment. All EPA licences and works approvals must be consistent with this policy. This policy is currently being updated and will become a Schedule to the statewide policy (Waters of Victoria). A draft for public comment was released in December 1995 and should be finalised by 1997.

The beneficial uses for the creek are different for the upstream (rural) segment and downstream (urban) segment, with the upstream segment given a higher value.

The environmental indicators for the SEPP are mainly physico-chemical parameters, including things such as: dissolved oxygen, E. coli, pH, temperature and toxicants. These, along with the identified beneficial uses for the Merri Creek, are outlined in Appendix 1.

SEPP (Waters of Victoria)

Most of the provisions for the waterways of the Merri Catchment are covered in more detail in the SEPP that was developed for the Yarra catchment in 1984. However, the SEPP for the Yarra River is currently being updated, and will be included as a schedule to the SEPP (Waters of Victoria).

The new schedule of the SEPP (Waters of Victoria) has not yet been released for public comment, it is expected to contain a number of revisions (R. Costello, pers. comm.), which may include:

The beneficial uses have been updated, with more of an emphasis on the protection of aquatic ecosystems. Primary contact is set as a beneficial use by 2003.

The water quality objectives to protect the beneficial uses will be those specified in the Australian Water Quality Guidelines for Fresh and Marine Waters and will generally be more stringent than the 1984 Yarra SEPP.

A number of new Indicators and Objectives have been added, of particular interest is a quantitative measure for nutrients; coprostanol as an indicator of human effluent; and the development of quantitative ecological indicators.

SEPP (Groundwaters of Victoria)

A draft SEPP (Groundwaters of Victoria) was released for public comment by the EPA (Vic.) in October 1994. The objective of this SEPP is to reserve groundwater resources that are free from contamination for future use and to protect the ecological values of surface waters. The water quality objectives of this SEPP are based on the National Groundwater Quality Guidelines and the SEPP (Waters of Victoria).

Page 30 State of the Environment Report - Introduction

Monitoring and Research

The EPA has carried out various monitoring programs and research on the Merri Creek and other waterways throughout the State. The objective of the EPA's monitoring network is to describe the environmental condition of Victoria’s waters, detect trends in water quality and to assess whether the water quality objectives are being met (EPA, 1993).

EPA Licences to Discharge Waste to Water

In the best interest of the aquatic ecosystem, no waste should be discharged to streams. However, in the absence of adequate sewage disposal infrastructure, the EPA licenses various organisations to discharge waste to water.

Licence conditions are determined by the EPA based on the type of industrial or sewage effluent and the impacts of these pollutants on the aquatic environment. It assumes that sufficient knowledge exists about the streamflow and basic physical, chemical and biological conditions of the stream in addition to the immediate and cumulative effects of such waste discharges on the aquatic environment. As will be illustrated in the Water Quality section, monitoring of the environmental condition of the Merri Creek is a relatively recent project and currently insufficient data exists to infer trends in water quality.

Such an approach also assumes that streams have an 'assimilative capacity' and are able to tolerate the limited input of waste materials without suffering ecological deterioration (OCE, 1988). In Victoria, where the environmental conditions are relatively unstable due to large variations in climatic conditions it is not possible to determine a state of equilibrium of a stream based on studies over periods of a few years.

There are a number of different types of licence as described in Box 7. In the Merri Creek catchment there are a number of licences to discharge waste to water. One of these licences, the Craigieburn Sewage Treatment Plant Licence has been discussed in Urbanisation. The other licences are listed in Table 3 and Table 4. These licences are scheduled (see Box 7 for explanation) and therefore of high local significance (Robins, 1994a)

Extractive industries are licensed to discharge contaminated stormwater; containing sediments and salts, and some trace contaminants such as nutrients, petroleum products, oils and heavy metals. Clay quarries are of particular concern as clay particles are easily suspended leading to increased turbidity, and the quarries in the Merri Catchment may also contribute high salt levels. (Robins, 1994a).

Discharges of sewage and sullage contain oxygen demanding substances and nutrients, and may also contain bacteria, viruses, cysts and worms (Robins, 1994a).

In the unsewered area of Campbellfield, Licence MW 1621 to the Arrowcrest Group allows the discharge of waste water of elevated temperature and containing trace contaminants of heavy metals (zinc, iron and chromium). The premises are allowed to discharge a maximum of 140 kL/day.

Page 31 Waterways of the Merri Catchment

Box 7 EPA Licences to Discharge Waste to Water

EPA licensing is divided into a number of areas depending on the source of wastewater:

Scheduled Premises are defined by law as premises requiring a works approval and/or licences to discharge waste to the water, land and air environments, and are only issued when no practicable alternative disposal method exists. The EPA licences and works approvals are issued and regulated by the EPA. The EPA SEPP is used as a guide to meet water quality objectives. Where objectives are not met, a mixing zone should be specified, and if an operator fails to meet the conditions of a licence they may be fined or prosecuted.

Exempt Premises are defined by law as 'scheduled' (as above), but not requiring a works approval or licence. Lists of scheduled premises and exemptions are established from the knowledge of the quality and quantity of waste typically produced by certain types of activities and how these impact on the environment.

Unscheduled Premises are not listed. Usually excluded because there is no point source discharge or the discharge has a low environmental impact. They must still meet the SEPP water quality objectives and a Pollution Abatement Notice may be served for failure to comply with these objectives. However, because of the diffuse nature of the pollution, it is often difficult to monitor and control unscheduled premises.

Diffuse sources are broad areas of land (rural & urban) which contribute pollution via runoff. Land use and quantity of runoff determines the relative importance of this source of pollution, but water quality information from the Merri Catchment waterways indicates that these are major sources of pollution

Page 32 State of the Environment Report - Introduction

Table 3 Extractive Industry Discharge Licences

Lic. No. Licensee Issued Street Name Suburb EW795 CSR Ltd Mar 91 Normandy Ave Thornbury EW285 Barro Group Ltd Mar 91 Newlands Road Coburg MW537 Brick & Pipe Oct 74 Bolinda Lane Campbellfield Industries Ltd MW538 Brick & Pipe Oct 74 Bolinda Lane Campbellfield Industries Ltd

Table 4 Sewage & Sullage Wastewater Discharge Licences

Lic. No. Licensee Issued Street Name Suburb EW704 Istra Social Club Nov 86 Cooper Street Campbellfield EX184 Melbourne Water * Apr 84 Hume Highway Craigieburn MW1041 Body Corp 11460 May 75 Northbourne Road Campbellfield MW1621 Arrowcrest Group Feb 91 Hume Highway Campbellfield P/L † MW1625 Twenty-Second Mar 78 Hume Highway Somerton Saldean P/L MW199 JJR Investments P/L Dec 73 Ainslie Road Campbellfield MW209 Mobil Nov 73 Coopers Road Campbellfield Accommodations P/L MW987 Poulos, Mary Feb 75 Hume Highway Kalkallo

* Craigieburn Sewage Treatment Plant † This is a metal finishing, as well as sewage and sullage effluent licence.

Adequacy of licence conditions for discharges of waste to water

The adequacy of the licence conditions for discharges of waste to water to protect the beneficial uses of the waterways in the Merri Catchment should be assessed. The State Environment Protection Policy requires that the discharges to water do not cause the water quality objectives set for the stream to be exceeded, yet these objectives are frequently exceeded in the Merri Catchment and licensed discharges to water, in addition to diffuse source inputs from polluted stormwater runoff, are likely contributors to stream degradation.

An unpublished supplementary document to the YarraCare Paper No. 7 (Robins, 1994b) discusses several of these issues as they apply to the Merri Catchment. While that document states that most of the licence conditions are satisfactory, it mentions concern with licence MW1621 for the discharge of treated process waste at temperatures of 37oC and notes that many of the licences have not been reviewed for over twenty years. The fact that this licence allows the discharge of heavy metals directly to the creek must be of some concern given that heavy metals accumulate in stream sediments, and that high

Page 33 Waterways of the Merri Catchment levels of metals are believed to be having a large impact on the health of the aquatic macroinvertebrate community (Mitchell & Clark, 1991).

Compliance with EPA licences to discharge waste to water

Even if the licence conditions set by the EPA are sufficient to protect the aquatic ecosystem, this is inadequate if these licence conditions are not being met by the licence holders. Evidence from Robins (1994b) indicates that this is the case in the Merri Catchment, where inadequate sampling and recording of discharges is taking place and where "compliance is low for most of the data set and moderately satisfactory for a select few" (Robins, 1994b). Some examples of recorded failures to comply with EPA licence conditions are the release of heated (37oC) wastewater and the discharge of effluent with E. coli levels similar to those recorded in raw sewage.

EPA is currently completing a review of all small sewage treatment plants in the Yarra catchment. As a result of this review, most licences will be amended to better reflect existing conditions and expectations, and minimise impact.

EPA Licences to Discharge Waste to Air

Contamination of rainwater from airborne particules is a major source of pollution. The EPA has incorporated licences to discharge waste to air into the requirements of stormwater discharge for approximately 30 premises in the Yarra Catchment. However, these discharges only represent a small fraction of the contaminated stormwater coming from urban and industrial areas.

2.5.2 Other State legislation

Besides the Environment Protection Act (1970), a number of other State acts apply to the waters of the Merri Catchment, and are described in Appendix 2. The most important of these are the acts to do with planning issues (eg. the Planning and Environment Act and Local Government Act) as they have the potential to refuse or permit most of the practices that result in broad land use changes. Other acts such as the various “protection acts” are, as their name suggests, supposed to protect land, species and waters from degradation.

Page 34 State of the Environment Report - Introduction

2.5.3 Commonwealth strategies, legislation and policies

The Commonwealth strategy of most direct relevance to the future restoration of the Merri Creek waterways is the National Water Quality Management Strategy. There are a number of other strategies, acts and conventions (some of which are described in Appendix 3) which shape the Federal Government’s policies toward the environment.

National Water Quality Management Strategy

The National Water Quality Management Strategy, as the title suggests, aims to integrate water quality management at a national level. As an integral part of this strategy, the Australian Water Quality Guidelines for Fresh and Marine Waters has been established to provide numerical and narrative criteria to assist in the sustainable management of water resources.

The structure of the Australian Water Quality Guidelines is similar to those of the EPA (Vic) State Environment Protection Policy. It defines the environmental values (beneficial uses) to be protected, establishes water quality objectives that become the goals for management action, and sets key indicators of water quality to identify and measure the change in the environmental values.

The five environmental values considered in the national guidelines for both marine and inland waters (ANZECC, 1992) are:

• ecosystem protection, including protection of waters used for shellfish and fish production and by wildlife; • recreation and aesthetics; • raw water for drinking water supply; • agricultural water; • industrial water.

Of particular interest to this report are the guidelines for the protection of aquatic ecosystems and for the protection of human consumers of fish and other aquatic organisms, which are summarised in Appendix 11.

The national guidelines recognise the use of indicators is based on the assumption that:

• it is possible to specify particular indicators of water quality • there are particular measurable concentrations of these indicators that can be specified below which either adverse effects will not occur or the risk of such effects is low.

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2.6 Current Arrangements

The three tiers of Government in Australia each in their own way has an influence on the environment of the Merri Creek Catchment. The Federal Government, whilst having no direct control of any part, except the Broadmeadows Military Establishment and the Reserve Bank of Australia mint at Craigieburn, has indirect interests in many ways. It provides funding for JobSkills programs, Greening Australia projects (primarily through the One Billion Trees project), etc. It also grants recognition to areas of special interest or value such as National Trust sites.

The State Government, by way of its strategic planning, has an enormous impact on the catchment. It would be reasonable to assert that, the State Government being responsible for regional planning of the industrial and urban development of the northern suburbs of Melbourne, it is the architect of greatest change that has taken place in the catchment during European Settlement. Therefore the long-term policies that each successive State Government generally adheres to are critical in shaping the development in the catchment.

Local Government also has direct influence on the development of the catchment. Until recent council amalgamations, the catchment has been controlled by ten municipalities including Whittlesea, Broadmeadows, Preston, Coburg, Northcote, Brunswick, Collingwood, and Bulla. Since the amalgamations of 1993, this array has been reduced by four to the Cities of Moreland, Darebin, Hume, Yarra and Whittlesea and the Shire of Mitchell. Theoretically this should mean better co-ordination of the various inter-council projects. However, to date it seems not to be the case.

Historical Political Landscape

The Merri Creek runs through what many consider to be the Autralian Labor Party’s “heartland of the north”. People in the working class suburbs of Fitzroy, Brunswick, Northcote, Coburg and Preston have been strong supporters of Labor governments over the years and this may have been taken for granted somewhat. More recently governments have recognised the potential of the “Green Vote” in the electorate. Governments both Labor and non-Labor have traditionally been much more concerned about employment opportunities than preserving “Green Corridors” and the Merri Creek corridor is a good example of this. From the beginning of European settlement to the present day the Merri Creek and its tributaries have served as drains for the many industries that have developed along the banks. The cheap housing associated with industrialised areas, was affordable by the working class ensuring that the voters of the corridor were solidly behind the Labor Party.

One of the single most important decisions that has affected the Merri Creek corridor was in 1969, when the Bolte Liberal Government decided to build a freeway along the Merri Creek valley to link up with the Eastern Freeway at Alexandra Parade. This decision along, with the general increase in awareness of environmental issues in the early 1970s, led to the community galvanising in opposition to development along the creek. The formation of action groups opposing the construction of the freeway naturally followed. The Merri Creek Action Group and the Fitzroy Residents Association were at the

Page 36 State of the Environment Report - Introduction forefront of these groups, the latter commissioning the Public Interest Research Group (PIRG) study of the Merri Creek in 1975.

One year after publication of the study, co-operation between councils and the community resulted in the formation of the Merri Creek Co-ordinating Committee. Over the following thirteen years this committee not only successfully opposed the construction of the freeway (the F2) and powerlines but also built cycle paths and used environmentally sensitive flood mitigation measures on the Merri Creek (Taylor, 1994).

It is interesting to note that it is only recently (1992) that the proposal for a freeway in the lower part of the Merri Corridor was officially taken off the planning books. However, the plans for the freeway had some unexpected benefits for the creek. In 1974, the proposal blocked moves by the MMBW to “improve” the Merri. Earl (1974) states that“...Until such time as the route of the F.2 Freeway is determined and, most likely, until such time as the freeway project is started and the right of way for the future creek is cleared, it is considered that it is not practical to construct major permanent improvements to the creek...” As the proposal was “on the books” for so long, it may have been instrumental in deferring indefinitely such drastic works.

Current Political Landscape

Nevertheless, it is a sobering thought that had the freeway still been proposed now, under the Kennett Liberal Government, that community action may not have had the same power to block construction. The communities affected by the proposed extension and widening of the Tullamarine Freeway are finding this out to their detriment and primarily because they do not have the same structures in place (ie. an active, community-based management committee) and are struggling to have any input into that proposal. However, the current government is fast developing a reputation for minimal consultation with the community about important environmental decisions and it is debatable as to what, if any, influence such a management group as the MCMC would have if the government decided to put the freeway down the Merri Corridor instead.

2.7 Conclusions

People have played a large part in shaping the Merri Catchment into the state it is in today. There is evidence that the indigenous Wurundjeri people lived by the waterways and used many of the features in the environment in their lives. However, since European colonisation there has been a dramatic change in the state of the waterways as a result of human activities in the catchment.

Agriculture, industry and residential landuse have had an impact on the waterways, and will continue to affect them in the future. The main issues, as a direct result of human activities, are;

• loss of vegetation and habitat, through land clearance for agriculture • discharge of effluent to the waterways of the catchment from the Craigieburn Sewage Treatment plant and several EPA licensed industries

Page 37 Waterways of the Merri Catchment

• diffuse source input of pollutants to the waterways via the stormwater drainage system.

Many of these problems have grown out of the historical social, political and institutional systems in the catchment. Change to the structure of these systems is necessary before improvement to the quality of the waterways can be expected. These changes have been taking place over many years, as is evident in the community attitudes to the waterways, however more change is needed if the waterways are to be restored. These issues are raised again in the following sections, and the Action Plan provides a means of addressing them to restore the waterways of the Merri Catchment.

Page 38 State of the Environment Report - Introduction

Summary: Geomorphology and Flow

This section describes the major ways in the channel form and flow patterns of the Merri Catchment are known to have changed since European settlement.

The main surveys used in preparing this section are presented in Table 5.

Table 5 Overview of surveys examining geomorphology and flow in the Merri Catchment (n.a. means not applicable). Study Type Date Location Type of No. of parameter sites MMBW long- 1891 - 1974 Merri Creek flood levels 2 term MMBW period May 1974 Merri Creek flow, n.a. morphology PIRG review Dec. 1974-JanMerri Creek morphology 13 1975 N.M.Craigie overview Feb.-March 1994 all sig. streams morphology n.a. Melbourne long- May 1974 - Merri & Edgar flow 6 Water term

The major creeks in the catchment, as they exist today, are shown on Map 4.

The original form of the Merri Creek and its tributaries is thought to have been of a “chain- of-ponds” in the upper reaches, with a number of permanent or semi-permanent ponds connected by an intermittently flowing stream. In the lower reaches the form would probably have been a sequence of pools and riffles; deep pools with slow flowing water separated by shallow, rocky fast-flowing stretches.

A number of changes have occurred to the waterways since European settlement:

• Channel form is much altered - primarily as a result of channel straightening for agricultural and flood mitigation purposes. It is estimated that only 37% of the Merri Creek remains in a “natural” state, with 51% having had minor modifications and 12% having had extensive modifications (Craigie, 1994).

• Stream flows are also greatly altered, with those in the upper reaches being reduced by water harvesting and damming, and those in the lower reaches being vastly increased by an increased amount of stormwater.

• Changes to groundwater flows are even less easy to determine. The importance of groundwater is clear, but often overlooked - it contributes about 50% of the flow entering the Yarra River. A great deal is extracted via bores - annually 269 ML is extracted via 1027 registered bores in the “Basalt Plains” of which the Merri Catchment is about one fifth the land area (Haydon, 1994).

Page 39 Waterways of the Merri Catchment

Stormwater

In urban areas, an increase in impervious surfaces has led to an increase in stormwater, and hence an increase in peak flows during storm events. Both the volume and velocity of water in the system are increased, and the peak occurs much more quickly after a storm. The increase in stormwater has led to the construction of a network of drains leading to the Merri Creek. Many of the original natural tributaries have also been piped, for example the lower reaches of Merlynston Creek (or Merlynston Drain).

Flooding

In order to protect against flooding, largely caused by the increase in stormwater, a number of measures have been implemented, such as;

• the construction of 5 retarding basins - 3 on Merlynston Creek, 1 on Campbellfield Creek and 1 on Kalkallo Creek. A proposed basin on the Merri Creek at Campbellfield has yet to be constructed. • the construction of levee banks on the Merri Creek at Normanby Ave. and Anderson’s St, Sumner Avenue and Winifred St. • channel straightening and de-snagging • rock or concrete lining

Urban expansion in the catchment will continue to increase the likelihood of flooding unless measures are taken to reduce the volumes of stormwater produced.

Barriers to Flow

One of the most obvious changes in stream character is the blocking of flow by dams and retarding basins. Other than the retarding basins described above, the main barriers in the catchment are;

• Two artificial weirs - at Coburg Lake and Edwardes Lake - which have no low-flow outlets and hence in times of prolonged drought could stop flow downstream of the weir. • Dams on Strathaird Creek and Mittagong Creek

There are also a number of illegal dams in the rural areas of the catchment.

Drainage for Agriculture

In rural areas, a great deal of land has been drained for agriculture, resulting in loss of wetlands and straightening of the watercourses. The remaining wetlands are at;

• unnamed swamp east of Dunlop factory at Campbellfield • Hernes Swamp • Beveridge Swamp (on east side of Spring Street, Beveridge)

Page 40 State of the Environment Report - Introduction

Water Harvesting.

Water is harvested primarily in rural areas, both legally and illegally for irrigation and domestic purposes. Melbourne Water estimate that a total of 54.2 ML is harvested annually. Whilst representing only a small fraction (~0.32%) of the total flow entering the Yarra, the location of the water extraction, in the ephemeral upper reaches, means that the impact of this harvesting is much greater than it would be otherwise. During drought periods the effects of water harvesting on aquatic ecosystems is likely to be particularly important.

Conclusions

The main changes to the geomorphology and flow in the Merri Catchment are channel modifications such as straightening, snag removal, piping and rock lining, and flood mitigation measures such as construction of retarding basins and levee banks. Drainage of wetlands and the construction of dams are also major changes.

Page 41 Waterways of the Merri Catchment

Page 42 State of the Environment Report - Introduction

3. Geomorphology and Flow

3.1 Introduction

The geomorphology and flow of the Merri Creek and its tributaries have a major influence on the aquatic ecosystem, and in turn are influenced by it. For example, geomorphology and flow are major determinants of habitat, and hence the structure of aquatic communities, and vegetation is a major influence in the processes of erosion and deposition (Petts, 1994).

In this section the “natural” and existing states of the geomorphology of the Merri Catchment are discussed, as well as three aspects of flow; stormwater, groundwater and overland flow. The information presented in this section is compiled from a number of sources, of which the major works are listed below.

3.1.1 Previous work

The morphology and flow of the Merri Catchment has not been analysed in detail to date. Most of the work has gone into flood prediction and prevention efforts. The only study to examine stream form for the whole catchment in any depth is by Craigie (1994). As a result, much of this section is based on that work. The most important studies are:

Melbourne & Metropolitan Board of Works (Snowy Mountains Engineering Corp., 1976) studies of flood events from 1891 to 1974. Significant flood events were recorded prior to 1974 (data given in height at certain gauges).

Melbourne & Metropolitan Board of Works (Earl, 1974) study May 1974. This agency conducted an investigation into the causes of the disastrous floods of 15, 16 of May 1974. This work describes aspects such as geology, physiography, urban development and flood mitigation options.

Melbourne Water Corporation (various reports) streamflow monitoring study from May 1974. This study, instigated as a result of the floods, records flow rates from various sites on the Merri Creek from Craigieburn to St Georges Road. Telemetry is now the common method of measurement but this was not always the case. Most reliable low-flow information is from Craigieburn and St Georges Road.

N.M. Craigie & Associates (Craigie, 1994) study of February/March 1994. Craigie broadly surveyed the character of the beds, banks, channels, valleys and streamworks of all the major streams in the Merri Catchment as part of the “Inventory of waterways of the Yarra Catchment” study of the condition of streams.

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Box 8 Rates of Change in the Merri Catchment

It is easy to think of a stream or river system as being constant with time (ie. being in equilibrium) and in some senses this is true - for instance over the period of a few minutes or hours or even days, it might appear so. However a more thorough understanding reveals that over longer periods this is not the case. The changes in channel form are affected mainly by erosion and sedimentation and these are dependent on stream power. Thus erosion takes place in areas and at times when the stream power is high and deposition occurs in areas where the stream power is reduced. Thus climate, which itself is not static or predictable, is integral to the process.

Erosion is a function of volume of water and flow velocity such that when these are maximised, so the erosion will be. From this it follows that events such as flow during floods (stormflow) will be more important in causing erosion than normal or base flow and the bigger the flood event the greater the erosive capacity.

The basic geomorphic form of any creek is determined by the underlying geology of the rocks through which the creek passes. For any catchment the geomorphic form changes from the headwaters to the outflow and this is basically dependent on the gradient of the slope of the channel. The different forms present in the Merri Catchment are; headwaters; swampy alluvial fans; chain-of-ponds type trunk stream; trunk stream.

The natural processes that are occurring in each of these morphological settings are different and occur at different rates. So that when we come to examine changes to the system, we must bear in mind these natural rates of change. Having said that, there can be no doubt that the changes brought about by humans since European settlement are significant. However, in the longer term (geological time scales), the changes to stream morphology are probably not of such consequence (ie. streams will recover their natural form given time). That is not to say that the changes wrought by human landuse changes do not have adverse impacts on stream ecology.

However, the changes since European settlers came to this country are immense and occur over a very short time frame. One of the most obvious changes in stream character is the blocking of flow by dams and retarding basins. In the Merri Catchment there are quite a few of these (see flood control mechanisms). Changes to the channel include widening, straightening, de-snagging, bank protection by rock walling or tree planting and streambed lining with rocks or concrete.

Scope of this section

The purpose of this section is to examine the current state of the processes that affect the geomorphology of streams in the Merri Catchment. This is achieved by examining the data on the Merri Creek in detail for characteristics such as stream type and flow, floodplain features, channel origin, bed composition and stability, aquatic structure, bank stability and bedworks. Although streamflow is very important in shaping habitat, anything more than a

Page 44 State of the Environment Report - Introduction broad consideration of its influence is beyond the scope of this study. The tributary creeks receive less attention than the Merri Creek trunk stream; this study includes only the channel origin and flow character. Some streams are so severely channellised as to become stormwater drains. This report gives some details of the main drains. The study also outlines the areas of wetland in the Merri Catchment.

3.2 “Natural” states

To understand the extent of the changes that may have occurred since European Settlement, it is important to try to understand what the system was like prior to colonisation. As with all aspects of the creek, this task is extremely difficult.

It has been suggested that parts of the Hopkins River in Western Victoria may be as close as one can get to a model for the condition of the Merri Creek prior to settlement (Rutherford, pers. comm.). The portion of the Hopkins River cited is where the stream has incised a deep gorge through the basalt plain across which it flows. This gorge has served as protection from the pressures of grazing, preventing major degradation of the channel. The morphology of the river that flows through the gorge is that of a chain-of-ponds type stream in which permanent or semi-permanent pools of very slowly moving or stationary water lie in the channel bed and are connected to each other by an intermittently flowing stream.

It might also be possible to gain an idea of the original flow form by examining data gathered over recent times to develop a model of changes over this period and extrapolating backwards in time. Whilst this is theoretically possible, it has not been attempted to date. This is probably because of lack of necessary data - monitoring of daily flows on the Merri Creek commenced in 1975, at just two locations.

The difficulties illustrated by these two accepted methods means that determining “natural” flows is based on assumptions and personal belief.

3.3 Existing states

As described in Human Environment, the physical landscape has changed markedly in the two hundred or so years of European settlement. It is therefore not surprising that the environment of the Merri Creek and its tributaries have also changed a great deal.

The major changes include:

• habitat destruction from flow changes, channel erosion and channel improvements • increased flows, volumes, and velocities of runoff particularly during storm events • decreased groundwater recharge

These changes are discussed in the following section.

The Merri Catchment can be divided into broad geomorphological settings, which form a useful basis for describing human-induced changes, eg channelisation. In this section, the

Page 45 Waterways of the Merri Catchment

Merri Creek is described using these broad settings. A brief summary of the form and flow of each significant tributary is also presented.

3.3.1 The Merri Creek

The Merri Creek has its origins on the south side of the Great Dividing Range. From there the creek fairly quickly drops to 300 m (127 m in 5 km) and then takes 22 km to reach the 200 m contour level (100 m in 22 km). The creek then falls the next 100 m in the next 12 km before dropping a further 80 m, at which point it joins the Yarra River just above Dight's Falls in Collingwood (80 m in 15 km). The total length of the creek is around 73.3 km. Craigie has divided the creek into ten reaches, which may be grouped into five sections of similar morphology (shown on Map 4); headwaters; swampy alluvial fan; chain-of-ponds; moderately-sized stream; and the main trunk stream (after Craigie; 1994). The condition and degree of alteration of each of the parameters described by Craigie are qualitative judgements and based on his extensive experience in assessment of stream morphology.

The Headwaters: upstream of Station Road

A number of small streamlets and gullies run off the hills of the southern slopes of the Great Dividing Range between Heathcote Junction and Yabamac. The highest of these hills is The Birdies at 427 metres. Craigie (1994) describes the lower two thirds of this section only (commencing three kilometres upstream of Station Road). A small trapezoidal channel (less than five metres wide, measured at bankfull flow) through a flat floored valley surrounded by rolling hills distinguishes this reach. This description suggests that the floor has minor alluvial deposits in it. The channel is reasonably straight having had minor modifications. The stability of the verge is excellent but the banks are slightly unstable and erosion has been a problem at times. There is negligible flow through disconnected but relatively permanent pools. The bed material is bi-modal; being composed of clay and gravel. The aquatic structure (the physical sub-surface condition of the bed) is moderate; the excess of clay degrading the stream habitat.

The upper reach (previously undescribed) is made up of a dendritic pattern of eight to ten gullies up to two kilometres long cut into the Silurian mudstone and siltstone bedrock (Earl, 1974). Flow in these creeks is intermittent. The urban development of Heathcote Junction has altered some of the creeks quite considerably.

In naturally vegetated areas it is expected that these settings are stable over periods of 100 years or so.

Swampy Alluvial Fan: Station Road to “Camoola”

Upon union of these diminutive streams at the base of the hills, the gradient of the creek flattens out. As the gradient lessens, the water velocity drops and the sediments being carried in the water are deposited to form the swampy alluvial fan. This fan is composed of sand and silt with some clay. The exposed extent of this sediment is from a short distance north of Station Road, Wallan East south to “Camoola” station, distance of five kilometres.

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This deposit reaches up the valleys of the main (Mittagong and Taylors) creeks that join the Merri Creek here (Earl, 1974).

Craigie (1994) describes the creek that flows through this floodplain as having a regular meandering pattern. Though the small (less than five metres), trapezoidal channel follows a basically natural course, it has been straightened considerably. The banks and the verge are quite stable. Flow in this section of the creek is negligible. The bed, as is expected, is muddy and silty but its aquatic structure has been destroyed by the remodelling works leaving no protection for aquatic fauna. As the name suggests, wetlands are closely associated with this morphology,

The cycle of erosion and deposition that forms these environments is thought to take place over periods of the order of 1000 years. However, catastrophic events can cause incisions over periods of around 100 years.

Chain-of-Ponds stream: “Camoola” to “Merri Creek Park”

After depositing its load of coarse sediment on the floodplain, the creek begins a gradual descent across the basalt plain that covers most of the catchment. The basaltic lava flowed from a row of vents that stretch from Pretty Sally on the Great Divide to Mount Ridley near Craigieburn (Earl, 1974). The now dormant cones erupted around about two million years ago (Page, 1968). The creek, as it flows past Merriang, runs up against the Silurian hills on the eastern edge of the catchment (Earl, 1974).

Craigie (1994) describes the third and fourth reaches as being a minor stream (less than 10 m wide and 1.5 m deep) meandering irregularly through a wide lowland valley. The channel is in a near natural state, having had minor straightening and de-snagging in the upper portion only. Bank erosion in some parts points to some instability (probably caused by cattle trampling). The bed consists of mud and silts with some sands in the reach around Merri Creek Park. Its aquatic structure is very poor; the excess of clay and the streamworks degrading the stream habitat. The stream itself hardly flows at all in normal conditions and consists of disconnected but permanent pools separated by reedy growth.

The time taken for this type of environment to form is not clear but is probably of the order of thousands of years.

Earl (1974) depicts a swamp on the west side of the Merri Creek between “Merriang” and “Merri Creek Park”. This swamp no longer appears on maps so has probably been drained.

Moderately sized stream: “Merri Creek Park” and Craigieburn

In its fifth, sixth and seventh reaches, as described by Craigie (1994), the Merri Creek is a moderately sized stream (10 to 20 m wide and 1.5 to 3 m deep). It initially meanders irregularly through a wide lowland valley before being confined to an incised valley around Donnybrook. The channel is in a near natural state, having had minor straightening and de- snagging in the reach between Bald and Woody hills. Bank stability is good in all parts. The bed material is more coarse compared to the previous sections. It consists of sands, gravels and pebbles with some boulders. Bedrock is exposed near Craigieburn. The aquatic structure is much improved having retained much of its quality and diversity. The stream itself flows slowly through emergent vegetation.

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Map 4 Reaches of the Merri Creek

Page 48 State of the Environment Report - Introduction

Quaternary alluvium in the valley, west of the Silurian outcrops at Summer Hill, indicates a prior floodplain through which the creek is eroding (Earl, 1974).

As with the previous and the next section, the time taken for this type of environment to form is not clear. It is probably of the order of thousands of years or more.

Main Trunk stream: Craigieburn to the Yarra

Craigie (1994) describes the three reaches of the stream downstream of Craigieburn as major. It is at Craigieburn, that the substantial tributaries of Malcolm and Aitken creeks join the Merri Creek. The creek’s principal feature is the incised valley that it is carving though the basalt plain over which it flows. The valley deepens as the creek flows south. Downstream of Cooper Street the valley walls narrow to form a picturesque gorge. At Barry Road the gorge opens out to a small floodplain and the creek deposits some of its sediment load as Quaternary Alluvium (Earl, 1974). Further south, Central Creek joins the Merri Creek below Mahoneys Road and then Merlynston Creek (drain) joins at Carr Street. Shortly after this, the creek flows into Coburg Lake. A little below the weir, Edgars Creek runs into the Merri Creek. All creeks that join the Merri Creek hereafter have been turned into drains.

The channel is in a less than natural state for much of this section, having been increasingly more modified downstream of Coburg Lake. The nature of these modifications (Earl, 1974) are;

• minor re-alignment during main sewer construction (1965) and later levee construction between Miller Street and Normanby Avenue in Thornbury; • one bend removed and banks filled (now Northcote Golf Course) as part of bridge construction works (1945) south of Normanby Ave; • creek straightened (1927) and banks stabilised after flood damage (1954) at Auburn Avenue in Northcote; • meander removed (1937-38) at Sumner Avenue in Northcote; • banks filled (between mid 1940s and 1950) and stabilised with rocks (1955) and later levee construction at Merri Park on the east bank in Northcote, • construction of a four metre wide and one metre high grouted rock-walled channel (1927- 29) between St Georges Road and Ramsden Street in Clifton Hill which lasted until the 1934 flood.

Since the 1934 flood no major work has been done, apart from clearing and maintenance. In general, the banks are stable but modifications are causing instability in places.

The flow of the water in the reach from Craigieburn to Cooper Street is mainly slow through emergent vegetation. From there on, the flow is non-uniform, with runs, glides, riffles and long pools. The bed material over which the creek flows varies from sandy and gravelly through to boulder-sized rocks and exposed bedrock (especially upstream of Coburg Lake). The aquatic structure is generally good, however it deteriorates below Coburg Lake.

Over its whole length, in terms of its channel origin, the Merri Creek can be classed as; 37% of the total length of the creek is in a natural state, 51% is natural but has had minor modifications and 12% is natural but with extensive modifications and flow character; the upper 39% of the creek has negligible flow in permanent pools; the middle 31% has water

Page 49 Waterways of the Merri Catchment flowing slowly through emergent vegetation; and the lower 30% is a slow, non-uniformly flowing stream.

3.3.2 Summaries of the Significant Tributaries

This summary is based on the work of N.M. Craigie & Associates (Craigie, 1994). They divide each stream into a series of reaches based on generally similar features such as channel, bank and verge characteristics. This section deals with the channel origin and the flow character alone and lists the creeks as they join the Merri Creek from its headwaters to its mouth.

It is worth noting that N.M. Craigie & Associates acknowledge that the classification of the catchment in this manner is quite broad and can be refined by more detailed study. However, this is the best available work that covers the whole watershed.

Mittagong Creek

This creek is the northernmost headwaters of the Merri Creek system but joins Wallan Creek before the Merri Creek near the Hume Freeway. Craigie classed it as having only one reach. From its beginnings to its confluence with Wallan Creek, Mittagong Creek is 5 km long.

Although the channel is essentially natural in origin, there has been extensive modification to it. There are several large on-stream dams and the stream from William Street in Wallan to its confluence with Wallan Creek has been straightened somewhat.

The flow is generally negligible but there are disconnected but relatively permanent pools. The dams constructed obviously control the flow.

Wallan Creek

This creek in the headwaters of the Merri Catchment arises on the south side of Pretty Sally on the Great Dividing Range. It flows south then east through the township of Wallan into the Merri Creek near Wallan East, a total distance of nearly six kilometres. The creek has been divided into four reaches.

The uppermost reach, which has not been described by Craigie, flows through farmland and the urban fringe a distance of 1.2 km. It is likely that the form has not been altered much. The sections of the creek downstream of the township, 65% of the total length (5.35 km), have been substantially altered. These alterations include channel enlargement, installation of a low-flow pipe, channel straightening, channelisation and de-snagging.

The uppermost reach is characterised by a stream flowing slowly through emergent vegetation. The middle reach has not been classified as it has a low-flow pipe. The section from the Hume Freeway to the Merri Creek does not normally flow but has disconnected and semi-permanent pools.

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