Data Interpretation and Analysis of Citizen Science Data ...

Data Interpretation and Analysis of Citizen Science

Data from the Barwon River

Contents Acknowledgements ................................................................................................................................... 1

Acknowledgement of Country .............................................................................................................. 1

Acknowledgement of Citizen Scientists ............................................................................................. 1

Introduction ................................................................................................................................................. 2

The Corangamite Catchment Management Authority ..................................................................... 2

Citizen Science in Corangamite .......................................................................................................... 3

The Waterwatch Program ................................................................................................................ 3

The EstuaryWatch Program ............................................................................................................. 4

Additional Citizen Science Projects in Corangamite .................................................................... 5

The Barwon River Catchment.............................................................................................................. 7

Sub-Catchments and Monitoring Sites ............................................................................................... 8

Methodology ............................................................................................................................................... 9

What data is collected and why ........................................................................................................... 9

Water quality, parameters monitored and what they mean ........................................................ 9

Assessing against appropriate triggers/levels/indexes, a comparison with State

Environment Protection Policies (SEPP (Waters) 2018) ........................................................... 10

Water quality analysis ..................................................................................................................... 10

Aquatic macroinvertebrate, why they are monitored and how they are analysed ................. 12

Data analysis and interpretation ............................................................................................................ 13

The Upper Barwon landscape zone ................................................................................................. 13

The Mid-Barwon landscape zone ...................................................................................................... 24

The Leigh landscape zone ................................................................................................................. 31

The Moorabool landscape zone ........................................................................................................ 43

The Bellarine landscape zone ........................................................................................................... 55

Summary of waterway condition ........................................................................................................... 69

Limitations ................................................................................................................................................. 73

Recommendations ................................................................................................................................... 73

Executive Summary

Citizen scientists of the Waterwatch and EstuaryWatch programs have been monitoring the water

quality within the Corangamite Catchment Management Authoritiy (CMA) region of Victoria for the

past twenty-six and fourteen years, respectively. These citizen science programs deliver an

extensive range of waterways education experiences to the community and work in partnership with

local governments, friends groups and other stakeholders to promote the conservation and

protection of local waterways. These programs raise awareness and understanding of local

waterway issues and provide water quality monitoring training and support to local volunteers.

This report is an analysis of data collected by citizen scientists from locations throughout the Barwon

River catchment in the Corangamite CMA region of Victoria. The purpose of this report is to inform

and increase the knowledge of citizen scientists, managers and the broader community of the health

of waterways in the Barwon River catchment.

The Barwon River flows in a north easterly direction, draining the northern slopes of the Otway

Ranges and taking in a number of small tributaries before reaching the basalt plains in the centre of

the basin. Inverleigh is the confluence of the Barwon and Leigh rivers. The Leigh River originates as

the Yarrowee River in the Central Highlands near Ballarat and flows southwards to join the Barwon

River. The Barwon River then flows east across inland plains and takes in the waters of the

Moorabool River at Geelong. The east and west branches of the Moorabool River rise in the ranges

in the Wombat State Forest and below Mt Buninyong respectively, and flow in a southerly direction

meeting to the north of Morrisons. From Geelong the river flows to the lower breakwater and enters

the Barwon River estuary before discharging to Bass Strait at Barwon Heads.

This report assesses data from 2005 to 2020 from currently active sites across the catchment. The

water quality and aquatic macroinvertebrate data is analysed to determine trends over time and

across the catchment using graphs generated by the Waterwatch and EstuaryWatch databases.

This data is then assessed against the State Environment Protection Policy (SEPP) Waters

Environmental Quality Objectives which outline specific regional water quality objectives for the

protection of rivers and streams across Victoria.

The overall water quality of the Barwon River from the headwaters to the mouth of the estuary

indicate the waterway to be in marginal to good condition, influences from most tributaries are

evident, displaying areas impacted by both high and low pH levels, high salinity and turbidity and

excessive nutrients such as phosphorus. High oxygen levels also indicate the potential for algal

blooms within the rivers, likely associated with high nutrient levels particularly in the warmer months

for much of its length.

The monitoring by Waterwatch and EstuaryWatch is vital for assessing the general water quality

conditions within these waterbodies and should be continued. This report has identified times when

the water quality is reduced. At times when particular water quality parameters exceed the expected

range additional monitoring could be conducted to determine if it is localised or throughout the

waterway. Additional monitoring assessing the duration of reduced water quality could also be

undertaken. Event based monitoring such as during times of environmental watering could also be

undertaken to gain a better understanding of how the water quality changes at these times.

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Acknowledgements

Acknowledgement of Country

The Corangamite Catchment Management Authority acknowledges the Traditional Custodians of the

land and waters where we work, and pay our respects to the Elders past and present and emerging.

The Aboriginal Traditional Owners have existed as part of the land for thousands of generations and

have an intrinsic connection to the land, the rivers and the sea. The Corangamite Catchment

Management Authority recognises and acknowledges the contribution and interest of Aboriginal

people and organisations in waterway and land management. Recently, aboriginal water values

were identified in the Upper Barwon, Yarrowee and Leigh rivers flows study update (2019)i and

incorporate traditional ecological knowledge. Similarly, it is recognised that the rivers in this report

will have culturally significant species and places for the Wadawurrung and Eastern Maar People.

Acknowledgement of Citizen Scientists

The Corangamite Catchment Management Authority would like to acknowledge the efforts of

volunteer citizen scientists. These volunteers have spent countless hours monitoring waterways,

collecting data and informing on their local environments, providing valuable information for

managers and assisting in educating the broader community. Citizen scientists, including

Waterwatch and EstuaryWatch monitors, are provided with this report to give more feedback on the

results of the monitoring data they have collectedii.

Above: Barwon River at Buckley Falls, Geelong. Photo Corangamite CMA

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Introduction

This report is an analysis and interpretation of data collected by Citizen Scientists from locations

throughout the Barwon River catchment in the Corangamite CMA region of Victoria. The purpose of

this report is to inform and increase the knowledge of Citizen Scientists, managers and the broader

community of the health of waterways in the Barwon River catchment.

The Corangamite Catchment Management Authority

The Corangamite Catchment Management Authority (Corangamite CMA) was established in 1997 to

ensure the protection and sustainable development of land, vegetation and water resources within a

boundary stretching from Geelong to Ballarat and along the Surf Coast to Peterborough.

Approximately 420,000 people live in the region’s 13,340 square kilometres of south-western

Victoria and 175 kilometres of coastal fringe.

The region is defined by four river basins – the Moorabool, Barwon, Lake Corangamite and Otway

Coast.

The Corangamite CMA work with land managers, communities, other organisations and

governments to protect and improve the health of the region’s natural resources (water, soils,

biodiversity) to improve the health and sustainable productivity of the Corangamite region. In 2013

the Corangamite CMA developed the Corangamite Waterways Strategy 2014 -2022 iii to guide

management of waterways, wetlands and estuaries within the region.

Supporting local communities and increasing knowledge of their local environment is a key objective

for the Corangamite CMA. The Corangamite CMA support, train and manage many local citizen

scientists participating in projects within the region.

Above: Community preparing for eDNA water sample collection to detect presence of platypus in Upper Barwon. Photo Corangamite CMA

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Citizen Science in Corangamite

Citizen scientists of the Waterwatch and EstuaryWatch programs have been monitoring the water

quality within these waterways for the past twenty six years and fourteen years respectively. These

citizen science programs deliver an extensive range of waterways education experiences to the

community and work in partnership with local governments, friends groups and other stakeholders to

promote the conservation and protection of local waterways. The programs raise awareness and

understanding of local waterway issues and provide water quality monitoring training and support to

local volunteers. There have also been many additional programs conducted with the support of

citizen scientists collecting monitoring data, several of which were instigated by the local

communities to gain a better understanding of potential threats to their local environment eg Upper

Barwon Landcare Network (UBLN) eDNA survey of platypus in 2018 and 2019, Barwon Estuary

Monitoring Pilot Program (BEMPP).

The Waterwatch Program

For more than twenty six years, the Waterwatch Program has been connecting local communities

with waterway health and sustainable water management issues. Through the Waterwatch Program,

citizen scientists are supported and encouraged to become actively involved in local waterway

monitoring and on-ground activities.

Waterwatch has been operating in the Corangamite region since 1995. Since then numerous

volunteers have spent time collecting valuable data from waterways. In many instances this is the

only data collected at these particular sites. There are currently 62 active volunteers monitoring 125

active sites in the Corangamite region. In addition, schools have been engaged with the freshwater

education program River Detectives.

The monitoring undertaken by the Waterwatch program follows standardised methodologies set in

Standard Operating Procedure manuals and Data Confidence Plans to ensure Waterwatch

Above: Waterwatch sampling aquatic macro-invertebrates. Photo Corangamite CMA

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produces credible data of a known quality ensuring the veracity of the data collected. The data is

stored on the State-wide Waterwatch Database. The data assessed in this report is mostly flagged

as minimum Standard 3 from active sites across the catchment.

The Corangamite Waterwatch Program monitors the following water quality parameters:

• Electrical Conductivity

• pH

• Temperature

• Turbidity

• Reactive Phosphorus

• Dissolved Oxygen

Additional to water quality monitoring, habitat surveys and aquatic macroinvertebrate (waterbug)

surveys are performed at many Waterwatch sites. Assessment of macroinvertebrate communities

enables an ecological assessment of the waterway health. Further information regarding monitoring

methods, data collection and assessment can be obtained from the Waterwatch websiteiv.

The EstuaryWatch Program

EstuaryWatch is a successful citizen science program that supports community members to actively

participate in the monitoring of estuary health. EstuaryWatch volunteers are passionate about their

local environment and meet once a month to collect valuable data on the condition of their local

estuary.

For fourteen years the EstuaryWatch Program has been connecting local communities with estuary

health. The EstuaryWatch program was established at the Corangamite CMA in 2006 in response to

a groundswell of community interest and a lack of long term data on the condition of Victoria’s

estuaries. There are currently 61 active EstuaryWatch volunteers monitoring 11 Estuaries in the

Corangamite region.

EstuaryWatch data has been used to educate and inform better estuary management. Water quality

data, estuary observations and photos collected by EstuaryWatch have been referred to as part of

algal bloom, fish death and storm surge response and has been incorporated into estuary

management plans, research projects and the decision support tool for artificial estuary openings in

Victoria, the Estuary Entrance Management Support System (EEMSS).

The monitoring undertaken by the EstuaryWatch program follows standardised methodologies set in

Standard Operating Procedure manuals to ensure EstuaryWatch produces credible data of a known

quality ensuring the veracity of the data collected. The data is stored on the State-wide

EstuaryWatch Database.

The Corangamite EstuaryWatch Program monitors the following water quality parameters:

• Electrical Conductivity

• Salinity

• pH

• Temperature

• Turbidity

• Dissolved Oxygen

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A multi-parameter meter measures the first four parameters at 10cm below the surface and then

every 50cm thereafter. The last reading is taken 10cm from the bottom of the estuary. Turbidity and

pH are only recorded at the top and bottom of the water column.

Additional to water quality monitoring, estuary mouth condition monitoring, and photo-point surveys

are regularly conducted. Estuary mouth condition monitoring takes place where the river meets the

sea. People often call this location the river mouth or estuary mouth. Each month EstuaryWatch

monitoring begins with estuary mouth condition monitoring. Volunteers take a series of photos of

the estuary mouth. These photos are taken from the same location each month so that the condition

of the estuary mouth can be compared over time. One month the estuary might be closed to the

sea, the next month it might be open to the sea. Further information regarding monitoring methods,

data collection and assessment can be obtained from the EstuaryWatch websitev.

Additional Citizen Science Projects in Corangamite

The Corangamite citizen science program facilitates engagement of community members in diverse

volunteer opportunities in addition to EstuaryWatch and Waterwatch activities. In the last three years

there have been diverse citizen science program delivered in the region.

In the Upper Barwon area citizen scientists have been involved in the Platypus eDNA Monitoring

Project as part of a large-scale platypus survey to help better understand the conservation status of

Platypus populations in Australia and identify key threats to local populations. Citizen scientists

collected water samples that were analysed for Platypus DNA to determine the presence of the

species in their local waterways. Seven sites in the Barwon River catchment have been monitored

by citizen scientists. Further information can be obtained from the cesar websitevi.

In the Geelong region, the Corangamite CMA partnered with the Australian Platypus Conservancy to

launch an innovative new program the Australian Platypus Monitoring Network (APMN). APMN is an

innovative citizen science approach to monitoring the platypus. Volunteers record platypus sightings

Above: Barwon EstuaryWatch monitoring on the jetty at Barwon River estuary. Photo Corangamite CMA

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at one or more sites using a standard visual survey method. Further information can be obtained

from the APMN websitevii.

The Pesticide Detectives is an extensive national citizen science project investigating the occurrence

and concentrations of pesticides used in homes and gardens as well as agricultural and urban

settings in Australia’s waterways. Six sites in the Barwon River catchment have been monitored by

citizen scientists. Further information can be obtained from the Pesticide Detectives websiteviii.

The National Waterbug Blitz is Australia’s first nationwide waterway monitoring event. Each year,

Australians are encouraged to become ‘Citizen Scientists’ and investigate how healthy their local

waterways and wetlands are, simply by exploring and identifying what aquatic macroinvertebrates

(waterbugs) they contain. The type and number of waterbugs found in a waterway can tell us a lot

about how healthy that waterway is. Four sites in the Barwon River catchment have been monitored

by citizen scientists. Further information can be obtained from the National Waterbug Blitz websiteix.

Driven by community interest, at the very bottom of the Barwon River catchment, the Barwon

Estuary Monitoring Pilot Project (BEMPP) was developed to monitor public health and recreational

water quality within the Barwon River estuary. Citizen scientists collected water quality information

along the Barwon River Estuary at eight sites in Barwon Heads and Ocean Grove. Each site was in

proximity to stormwater outfalls and areas of high recreational use. Regular monitoring of the

estuary’s physical, biological and chemical health assisted to develop an understanding of estuary

water quality. Further information can be obtained from the EstuaryWatch websitex.

The Victorian Index of Estuary Condition (IEC) (2018 – 2019) was undertaken in the Corangamite

region – the program aims to assess and report on the condition of estuaries across Victoria,

assisting in their management and provide a baseline for assessing long-term changes in estuary

condition. Corangamite CMA project officers and EstuaryWatch citizen scientists contributed to this

Above: Barwon River platypus eDNA surveys with Upper Barwon Landcare Network. Photo Corangamite CMA

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research by measuring a range of water quality parameters. Further information can be obtained

from the Third Index of Stream Condition Report xi.

Fluker Post Project was established in 2008 and has allowed community members to make

photographic contributions from fixed photopoints (Fluker Posts) to provide a permanent visual

record of the location. The program operates in two ways; through the Fluker Post App method and

through email contributions. The App and Fluker Post websitexii allow people to access photos of the

waterways and landscapes over time.

The Barwon River Catchment

The Barwon River flows in a north easterly direction, draining the northern slopes of the Otway

Ranges and taking in a number of small tributaries before reaching the basalt plains in the centre of

the basin. Inverleigh is the confluence of the Barwon and Leigh rivers. The Leigh River originates as

the Yarrowee River in the Central Highlands near Ballarat and flows southwards to join the Barwon

River.

The Barwon River then flows east across inland plains and takes in the waters of the Moorabool

River at Geelong. The east and west branches of the Moorabool River rise in the ranges in the south

west corner of the Wombat State Forest and below Mt Buninyong respectively, and flow in a

southerly direction meeting to the north of Morrisons. The Moorabool River then flows south to join

the Barwon River at Geelong which then discharges from the estuary into Bass Strait at Barwon

Heads. From its highest point, the river descends 295 metres over its 160-kilometre course. The

Barwon River catchment has a total area of 388,007 hectares and the Moorabool River has a total

area of 217,042 hectares.

Above: Citizen scientist in the BEMPP program are trained in sample collection at Barwon Heads. Photo Corangamite CMA

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The Barwon River basin is a major water supply for Geelong, smaller urban centres, and farm water

supply for the region. The system is significantly altered via extensive farm dam storages, on-stream

reservoirs and many diversion licences. Flows in the upper and mid reaches of the system are

important contributors to the internationally significant wetlands including Lake Connewarre, Reedy

Lake and the Barwon River estuary system. The Lake Connewarre complex is located between

Geelong and the Barwon Heads. It forms part of the Port Phillip Bay (Western Shoreline) and

Bellarine Peninsula Ramsar Site. The Lake Connewarre complex includes Lake Connewarre, Reedy

Lake, Hospital Swamp, Salt Swamp, the Barwon Estuary and part of Lake Murtnaghurt.

Recent assessments of the ecological condition of the river system, as part of the Corangamite

Waterway Strategy (2014-2022) and Index of Stream Conditionxiii, have indicated that most reaches

are in moderate condition (previously, most were in marginal to very poor condition), however, there

are still very few streams in good or excellent condition.

Sub-Catchments and Monitoring Sites

For this report the complete Barwon River catchment is divided into sub-catchments according to the

CCMA landscape zones (Figure 1). The five zones are Upper Barwon, Mid-Barwon, Leigh,

Moorabool and Bellarine. A total of 46 Waterwatch and 5 EstuaryWatch sites are assessed across

the whole catchment.

Figure 1. The CCMA landscape zones used to cover the Barwon River catchment. (Map sourced from CCMA CWS 2013)

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Methodology

What data is collected and why

All water quality data in this report was downloaded from the Waterwatch and EstuaryWatch Data

Portals. The downloaded data was checked for quality prior to the analysis to remove any potential

errors. Aquatic macroinvertebrate data was obtained from the National Waterbug Blitz website.

This report assesses data from 2005 to 2020 from currently active sites, not all sites have data from

2005, monitoring commenced in 2017 at some sites. The number of monitoring events at each site

also varies across the catchment some sites have monthly monitoring whereas others are monitored

on an irregular basis.

Water quality, parameters monitored and what they mean

Temperature is a measure of the amount of heat in the water, that is, how hot or cold a river is. It is

measured as degrees Celsius (°C). The temperature of water influences and regulates many

chemical, physical and biological processes. Plants and animals usually have a temperature range

that they best grow, feed and reproduce in. Importantly, temperature regulates oxygen solubility in

water and as temperature increases solubility decreases.

The pH of water is a measure of its acidity or alkalinity. It is measured in pH units, the pH scale is

logarithmic and as a result, each whole pH value below 7 is ten times more acidic than the next

higher value. pH below 7 is termed ‘acidic’, a pH greater than 7 is termed ‘alkaline’, and when the

pH is 7 it is termed neutral. The pH of a water body can have serious direct and indirect impacts on

the organisms living within the water and on the potential uses of the water. Additionally, increased

pH raises toxicity of ammonia, while decreased pH can increase the toxicity of some metals.

Electrical conductivity (EC) measures the flow of electricity in a solution. It is generally measured in

micro siemens per centimetres (µS/cm). Conductivity in a solution increases as the amount of salts

dissolved in the water increases. The relationship between conductivity and dissolved salt

concentrations is used as a measure of salinity. Freshwater aquatic organisms have different

tolerances to salinity, most freshwater aquatic organisms will not survive in high levels of salinity.

Dissolved oxygen (DO) is a measure of the concentration of oxygen dissolved in water. In this report

it is measured in percentage saturation (% saturation). Oxygen is essential for respiration by all

aquatic plants and animals. Without it they will die. Oxygen in water comes primarily from the

atmosphere. Diffusion across the water-air interface transfers oxygen to the water and this is

substantially increased by turbulent mixing of water with air. Oxygen in water can also come from

plants as it is produced during photosynthesis. The contribution of plants and in particular algae is

generally relatively small in a healthy river but may be substantial in highly nutrient enriched

waterbodies where plant productivity is high.

Turbidity is a measure of the clarity of water. It is measured in Nephelometric Turbidity Units (NTU).

As suspended particulate matter including clay, silt, detritus and plankton in the water increases, the

clarity decreases and the water takes on a muddy appearance. Turbidity reduces the amount of light

entering the water, which will reduce the growth of submerged aquatic plants including most

phytoplankton and smother habitat for aquatic invertebrates and fish.

Phosphorus is a naturally occurring element originating from minerals in rocks and is essential for

animal and plant life. It is measured in milligrams per litre (mg/L). In natural circumstances,

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phosphorus usually enters waterways from the weathering of rocks (inorganic phosphorus) and the

decomposition of plant and animal material (organic phosphorus). If phosphorus concentrations are

high enough, they can contribute to algal blooms and infestations of aquatic macrophytes. Excessive

algal and macrophyte growth can lead to smothering of habitat, clogging of waterways and overnight

‘oxygen troughs’. Due to the difficulties of measuring phosphorus the Waterwatch monitoring

measures reactive phosphate a component of the total phosphorus in water.

Assessing against appropriate triggers/levels/indexes, a comparison with State Environment

Protection Policies (SEPP (Waters) 2018)

A common approach to assessing environmental condition is to compare the condition of a particular

test site with a reference site or set of reference sites. Reference condition is usually defined as the

condition of an unimpaired, minimally impacted or best available waterbody.

The State Environment Protection Policy (SEPP) Watersxiv outlines specific regional water quality

objectives for the protection of rivers and streams across Victoria. This Policy adopts the risk-based

approach of the ANZECC Guidelines for determining whether a beneficial use is at risk. The non-

attainment of an environmental quality objective indicates that there is likely to be a risk to beneficial

uses. Further investigation is required to determine the actual risk to those beneficial uses and

identify actions to address the risks.

The sites of the Barwon River catchment are located within the Central Foothills and Coastal Plains

segment. The central foothills are generally above 200 m in altitude and the coastal plains are below

200 m in altitude. The majority of sites are within the segment lowlands of the Barwon and

Moorabool rivers whilst sites on the Moorabool River above Meredith are within the segment

uplands of the Moorabool River. Sites in Lake Wendouree are within the wetlands segment Shallow

inland – With an outlet. Two wetland sites in Geelong are within the wetlands segment Riverine -

Floodplain. Sites within the Barwon River estuary are within the Estuaries segment

A comparison against SEPP (Waters) objectives requires the calculation of percentiles using data

with a minimum of eleven sampling events over a twelve month period. For rivers and streams

dissolved oxygen requires the 25th percentile and the maximum value, pH requires the 25th and 75th

percentiles and electrical conductivity, turbidity, total phosphorus require the 75th percentile to be

calculated. The SEPP (Waters) recommend monitoring total phosphorus whereas Waterwatch

monitoring is for reactive phosphate. Reactive phosphate is a component of total phosphate and can

be used to assess against the objective value, though it will understate the total phosphorus present.

A comparison with estuaries objectives requires measuring the dissolved oxygen, pH and turbidity in

the bottom waters of a site in addition to surface water as occurs with rivers and streams.

Due to the varied frequency of monitoring across the catchment (many sites do not have the

required number (11) of monitoring events per year, annual assessments with SEPP (Waters) are

not performed. For each site the complete data set is assessed against the objectives, in some

cases this may be fifteen years of data whilst in others it may only be three years.

Water quality analysis

The water quality data is analysed to determine trends over time and across the catchment using

graphs generated by the Waterwatch and EstuaryWatch databases. The rating system below is

used to display the water quality of a site using indicators for each bioregion, as determined by

SEPP (Waters).

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Water quality ratings have been developed to align with SEPP (Waters) environmental quality

objectives. A guide for interpreting river health according to the water quality indicators of a site for

each SEPP (Waters) segment is below (Tables 1 – 5). Blue and green ratings meet SEPP (Waters)

objectives:

Table 1. SEPP (Waters) Segment - Central Foothills and Coastal Plains - Uplands of the Moorabool, Werribee,

Maribyrnong, Campaspe, Loddon Avoca, Wimmera and Hopkins basins (above 200m)

Rating

Electrical conductivity

(µS/cm)

Dissolved oxygen (% saturation) pH (pH units)

Turbidity (NTU)

Reactive phosphate (mg/L)

Excellent < 1,000 85 -110 6.8 - 7.6 < 10 < 0.03

Good 1,000 – 2,000 70 - 130 6.8 - 8.0 10 - 15 0.03 - 0.055

Fair 2,001 - 3,000 60 - 70 or > 130 6 - 6.8 or 8 - 9 15 - 100 0.055 - 0.1

Poor > 3,000 < 60 < 6 or > 9 > 100 > 0.1

Table 2. SEPP (Waters) Segment - Central Foothills and Coastal Plains - Lowlands of the Barwon, Moorabool,

Werribee and Maribyrnong basins and the Curdies and Gellibrand Rivers

Rating


(µS/cm)


Turbidity (NTU)


Excellent < 1,500 85 - 110 6.8 - 7.6 < 10 < 0.03

Good 1,500 – 2,000 70 - 130 6.8 - 8.0 10 - 25 0.03 - 0.06

Fair 2,001 – 4,000 50 - 70 or >130 6 - 6.8 or 8 - 9 25 - 100 0.06 - 0.1

Poor > 4,000 < 50 < 6 or > 9 ≥ 100 > 0.1

Table 3. SEPP (Waters) Segment - Shallow inland – With an outlet

Rating


(µS/cm)*


Turbidity (NTU)


Excellent < 1,000 85 - 110 6.8 - 8.0 < 10 < 0.03

Good 1,000 - 2,000 80 - 120 6.5 - 8.5 10 - 15 0.03 - 0.1

Fair 2,001 - 3,000 60 - 80 or > 120 6 - 6.5 or 8.5 - 9 15 - 100 0.1 - 0.15

Poor > 3000 < 60 < 6 or > 9 > 100 > 0.15 *Adapted from SEPP (Waters) Segment - Central Foothills and Coastal Plains - Uplands of the Moorabool, Werribee, Maribyrnong, Campaspe, Loddon Avoca, Wimmera and Hopkins basins (above 200m)

Table 4. SEPP (Waters) Segment - Riverine Floodplain

Rating


(µS/cm)*


Turbidity (NTU)


Excellent < 1,500 85 - 110 6.8 - 8.0 < 10 < 0.03

Good 1,500 - 2,000 80 - 120 6.5 - 8.5 10 - 15 0.03 - 0.1

Fair 2,001 - 3,000 50 - 80 or > 130 6 - 6.5 or 8.5 - 9 15 - 100 0.1 - 0.15

Poor > 3,000 < 50 < 6 or > 9 ≥ 100 > 0.15 *Adapted from SEPP (Waters) Segment - Central Foothills and Coastal Plains - Lowlands of the Barwon, Moorabool, Werribee and Maribyrnong basins and the Curdies and Gellibrand Rivers

Table 5. SEPP (Waters) Segment - Victorian Estuaries

Rating Dissolved oxygen - Top (% saturation)

Dissolved oxygen - Bottom (% saturation) pH (pH units)

Turbidity (NTU)

Excellent 85 - 125 50 - 110 7.5 - 8.0 ≤ 10

Good 80 - 130 30 - 130 7.0 - 8.0 ≤ 10

Fair 60 - 80 or > 130 10 - 30 or > 130 6 - 7 or 8 - 9 30 - 100

Poor < 60 < 10 < 6.0 or > 9.0 > 100

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Aquatic macroinvertebrate, why they are monitored and how they are analysed

Aquatic macroinvertebrate surveys are conducted at many Waterwatch sites across the Barwon

River catchment. The macroinvertebrate community of a site is assessed uses a simple biotic index

that uses the pollution tolerance levels of different macroinvertebrate types to create a site score and

water quality rating for the river. Waters with high scores are likely to have high levels of dissolved

oxygen with low levels of salinity, turbidity and nutrients (nitrogen, phosphorus). Still waters and slow

flowing lowland waters, by nature, will always produce a lower site score because the physical

habitat and chemical levels are naturally different. Few macroinvertebrate types that are rated as

very sensitive occur naturally in still waters or slow flowing lowland waters.

SIGNAL stands for Stream Invertebrate Grade Number Average Level, initial identification methods

employed by Waterwatch were at the Order level of taxonomy. SIGNALT is a water quality

assessment procedure developed for Waterwatch in collaboration with the annual National

Waterbug Blitz. SIGNALT uses features that are visible to the naked eye to identify

macroinvertebrates. Identifications result in data sets of mixed taxonomic levels, some at genus or

species, and others at higher levels. Each aquatic invertebrate is given a SIGNALT score depending

on their sensitivity to pollutants. By knowing the individual SIGNALT scores, the SIGNALT score of a

site can be calculated, and therefore its health, can be assessed. The weighted SIGNALT not only

evaluates aquatic macroinvertebrate community diversity but also the abundance of

macroinvertebrates to give a score or health rating for the site.

A guide for interpreting water health according to the SIGNALT score of a site has been developed

for Waterwatch is displayed in Table 6.

Table 6. Waterwatch aquatic macroinvertebrate SIGNALT score ratings.

SIGNALT score Rating

6.1 to 10 Your site is exceptional

4.9 to 6.1 Your site is healthy.

3.5 to 4.9 Your site is probably mildly polluted.

3.1 to 3.5 Your site is impacted.

1.0 to 3.1 Unfortunately your site is heavily impacted

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Data analysis and interpretation

The Upper Barwon landscape zone

The Upper Barwon landscape zone is located along the inland slopes and plains of the Otway

Ranges to the north of Lorne and east of Colac. Water mainly flows through the upper reaches of

the Barwon River and its tributaries. Grazing for livestock (beef, sheep and dairy) and forestry

dominate the area with 89% of the landscape dedicated to these practices.

There are 1,822 km of rivers and streams in the landscape zone many of these are minor with

intermittent flow. There are 53 wetlands in this zone making 1% of the total area. Significant

waterbodies include the West Barwon Dam, which provides drinking water for greater Geelong.

During the development of the Corangamite Waterway Strategy 2014 – 2022 the Upper Barwon

community identified the following key values their waterways provide:

• Support for Biodiversity including many significant species of fish and birds, remnant native

vegetation and flagship species including platypus

• Numerous opportunities for recreation including walking, swimming, camping, fishing boating

and kayaking

• Consistent use of waterways across the landscape for stock watering and other agricultural

activities.

Citizen science projects conducted in the Upper Barwon landscape zone:

• Platypus eDNA Monitoring Project 2019 – 8 eDNA sites that are also regularly monitored

Waterwatch sites

• The Pesticide Detectives - 2 sites that are also regularly monitored Waterwatch sites

Community groups active in the Upper Barwon landscape zone that have contributed to data

collection:

• Upper Barwon Landcare Network

• Birregurra community members

A total of fifteen monitoring sites are assessed in the Upper Barwon landscape zone for this project

(Figure 2Error! Reference source not found.).

14

Water quality assessment

Over the assessment period (2005 – 2020), the water quality in the Upper Barwon landscape zone

varied across the landscape. The water quality in the upper Barwon River declines as the river

descends through the rural catchment, partial due to inputs from smaller creeks entering the Barwon

River. Seasonal trends are evident in most indicators and many are influenced by varied river flows.

Many of these tributaries have intermittent flows and therefore are likely to have greater variability in

the measured water quality parameters.

The most upstream site CO_BAR010 near Forrest, below the West Barwon dam, displayed the best

water quality condition, with low turbidity, electrical conductivity (Figure 3) and reactive phosphate.

Low pH levels occasionally occur indicating acid sulphate soils may be present near the site. High

Figure 2. The location of sites represented as yellow dot with the site code in the Upper Barwon landscape zone. (Map sourced from CCMA CWS 2013)

15

reactive phosphate levels also occasionally occur and may encourage excessive macrophyte and

algal growth. At times of increased river flow or rainfall in the catchment turbidity rises.

Increases in electrical conductivity and reactive phosphate are evident at the next down-steam site

CO_WES010 (Figure 4). Low pH values were observed at most sites with sites CO_WES010,

CO_BOU009 and CO_PEN080 lower than most.

The water quality of the tributaries of the Barwon River generally displayed poor water quality. The

site on Boundary Creek CO_BOU009 (Figure 5) displays very low pH values indicating very acidic

conditions due to acid sulphate soils in the catchment. During drier times the creek becomes more

acidic. This site also displayed low dissolved oxygen levels and higher electrical conductivity.

The Dewings Creek site CO_DEW010 (Figure 6) on several occasions displayed high dissolved

oxygen maximum values indicating possible excessive macrophyte or algae growth at times. This

may also be promoted by the high reactive phosphate values observed. Downstream of the

Figure 3. Site CO_BAR010 displaying electrical conductivity and turbidity from 2005 to 2020.

Figure 4. Site CO_WES010 displaying electrical conductivity and reactive phosphate from 2006 to 2020.

16

confluence with Dewings Creek on the Barwon River is site CO_BAR016, this site displays low pH at

times, possibly influenced by discharge from Boundary and Dewings Creeks, lower levels have been

recorded since 2012. Both low and high dissolved oxygen levels are also evident (Figure 7).

The Mathews Creek site CO_MAT065 (Figure 8) displayed higher electrical conductivity, turbidity

and maximum dissolved oxygen levels, indicating potential excessive macrophytes or algae growth.

High turbidity values indicate high sediment movement in this creek.

Figure 5. Site CO_BOU009 displaying low pH values and low dissolved oxygen levels from 2005 to 2020.

Figure 6. Site CO_DEW010 displaying low dissolved oxygen and high reactive phosphate levels from 2005 to 2020.

17

The six sites on Pennyroyal Creek CO_PEN060 (Figure 9), CO_PEN070, CO_PEN080,

CO_PEN085, CO_PEN090 and site CO_DEM010 on Deans March Creek, a tributary which joins

Pennyroyal Creek above site CO_PEN085 display a distinct pattern of increasing reactive

phosphate and electrical conductivity down this catchment (Figure 10). The variable dissolved

oxygen levels observed, both very low and high levels indicate potential excessive macrophytes or

algae growth at times. Low dissolved oxygen levels return to healthy levels at the most downstream

site CO_PEN090 prior to entering the Barwon River.

The Barwon River, from its headwaters to Winchelsea shows increasing electrical conductivity and

turbidity. The two most downstream sites CO_BAR030 and CO_BAR040 (Figure 11) display

improved dissolved oxygen levels, though high maximum levels indicate potential excessive

macrophytes or algae growth.

Figure 7. Site CO_BAR016 displaying low pH and dissolved oxygen from 2007 to 2020.

Figure 8. Site CO_MAT065 displaying high turbidity from 2007 to 2020.

18

Figure 9. Site CO_PEN060 displaying low reactive phosphate and electrical conductivity from 2007 to 2020.

Figure 10. Site CO_PEN085 displaying the high reactive phosphate and electrical conductivity from 2007 to 2020.

19

How did the water quality compare to SEPP (Waters) environmental water quality objectives?

Sites on the Barwon River in the Upper Barwon landscape zone

The water quality in the Barwon River met most of the SEPP (Waters) environmental water quality

objectives for the Central Foothills and Coastal Plains - lowlands of the Barwon and Moorabool

rivers segment (Table 7), indicating beneficial uses are mostly protected.

• All sites displayed lower electrical conductivity than the objective (75th percentile < 2000

µS/cm).

• All sites displayed lower reactive phosphate than the objective (75th percentile 0.060 mg/L)

except site CO_WES010 (75th percentile 0.065 mg/L).

• Only two sites did not met the objective for turbidity these being CO_BAR020 (75th percentile

27 NTU) and CO_BAR040 (75th percentile 29 NTU), the observed values are very close to

the objective (75th percentile < 25 NTU).

• All sites were within the upper pH objective (75th percentile < 8 pH units). Three sites

CO_WES010 (25th percentile 5.89 pH units), CO_BAR016 (25th percentile 6.50 pH units) and

CO_BAR040 (25th percentile 6.73 pH units) exceeded the lower pH objective (25th percentile

< 6.8 pH units).

• Only two sites CO_BAR030 (25th percentile 70% saturation) and CO_BAR040 (25th

percentile 73% saturation) met the objective for dissolved oxygen (25th percentile > 70%

saturation) whilst three sites CO_BAR010 (max. 110% saturation), CO_WES010 (max.

128% saturation), CO_BAR020 (max. 114% saturation) met the objectives dissolved oxygen

maximum value (max. < 130% saturation).

Sites on tributaries of the Barwon River in the Upper Barwon landscape zone

The water quality of the tributaries of the Barwon River in the Upper Barwon landscape zone

displayed varied results.

• Site CO_DEW010 on Dewings Creek met the objectives for all indicators with the exception

of dissolved oxygen maximum value (max. 147% saturation) and lower pH objective (25th

percentile 6.23 pH units).

Figure 11. Site CO_BAR040 displaying the dissolved oxygen and electrical conductivity from 2005 to 2020.

20

• Site CO_BOU009 on Boundary Creek met the objectives for all indicators with the exception

of dissolved oxygen (25th percentile 28% saturation) and both the upper and lower pH

objectives (25th percentile 3.50 pH units and 75th percentile 4.50 pH units respectively).

These levels will most likely impact on the beneficial uses.

• Site CO_MAT065 on Mathews Creek met the objectives for all indicators with the exception

of dissolved oxygen (Max. 160% saturation), lower pH objective (25th percentile, 6.70 pH

units) and turbidity (75th percentile, 66 NTU). High turbidity may indicate high sediment

movement potentially putting beneficial uses at risk.

• On Pennyroyal Creek

o All sites met the upper pH objective (75th percentile, 8.00 pH units) however all sites

exceeded the lower pH objective (25th percentile 6.80 pH units)

o All sites exceeded the dissolved oxygen maximum objective (max. < 130%

saturation).

o Only two sites met the dissolved oxygen lower objective sites CO_PEN060 (25th

percentile 85% saturation), the most upstream site, and CO_PEN090 (25th percentile

86% saturation), the most downstream site.

o All sites met the turbidity and total phosphorus objectives with the exception of sites

CO_DEM010 (turbidity 75th percentile 37 NTU, reactive phosphate 75th percentile

0.076 mg/L) and site CO_PEN085 (turbidity 75th percentile 30 NTU, reactive

phosphate 75th percentile 0.088 mg/L).

o All sites met the objective for electrical conductivity with the exception of the two

most downstream sites CO_PEN085 (75th percentile 3405 µS/cm) and CO_PEN090

(75th percentile 2835 µS/cm).

Table 7. Water quality assessment against State Environment Protection Policy (Waters) for sites in the

Upper Barwon lanscape zone. (Blue and green indicate objective is met, beneficial uses are protected,

orange and red indicate objective is not met, beneficial uses may be at risk).

Dissolved Oxygen (% Saturation)

Electrical Conductivity

(µS/cm) pH (pH units)

Turbidity (NTU)

Reactive Phosphate

(mg/L)

Site Code Sample Count 25th% Max 75th% 25th% 75th% 75th% 75th%

CO_BAR010 136 65 110 180 6.80 7.50 10 0.030

CO_WES010 106 70 128 320 5.89 6.98 7 0.065

CO_DEW010 87 71 147 410 6.23 7.00 18 0.060

CO_BOU009 126 28 127 1094 3.50 4.50 12 0.040

CO_BAR016 137 53 135 584 6.50 7.53 12 0.038

CO_MAT065 78 74 160 1250 6.70 7.47 66 0.043

CO_BAR020 143 57 114 959 6.80 7.40 27 0.030

CO_PEN060 74 85 150 270 6.54 7.11 14 0.060

CO_PEN070 74 44 145 419 6.30 6.90 23 0.053

CO_PEN080 73 49 160 650 5.63 7.07 22 0.048

CO_DEM010 71 60 151 975 6.47 7.38 37 0.076

CO_PEN085 87 40 169 3405 6.65 7.32 30 0.088

CO_PEN090 78 86 156 2835 6.78 7.60 25 0.048

CO_BAR030 111 70 182 1100 6.89 7.60 22 0.040

CO_BAR040 113 73 168 1456 6.73 7.70 29 0.043

21

Aquatic macroinvertebrate assessment in the Upper Barwon landscape zone

Aquatic macroinvertebrate monitoring was undertaken at four sites in the Upper Barwon Landscape

Zone over the assessment period (Table 8). Two surveys were conducted at site CO_BAR010, the

weighted SIGNALT score indicated the site in 2011 to be moderately impacted and in 2016 to be

healthy. At site CO_BAR016 two surveys were conducted in 2013 and 2016, the scores indicated

the site to be mildly polluted on both occasions. Downstream at site CO_BAR020 in 2017 the score

indicates the site to also be heavily impacted. Whilst the score indicates the Pennyroyal Creek

tributary site CO_PEN080 in 2013 to be moderately impacted.

Table 8. Results of macroinvertebrate surveys in the Upper Barwon Landscape zone from 2005 to 2020.

Site Date Method Weighted SIGNALT Score

CO_BAR010 3 November 2011 Order 3.2

5 July 2016 ALT 6.0

CO_BAR016 28 June 2013 ALT 4.4

8 July 2016 ALT 4.3

CO_BAR020 2 May 2017 ALT 2.6

CO_PEN080 28 June 2013 ALT 3.3

Summary of the Upper Barwon Landscape Zone

As the Barwon River flows from the foothills of the upper catchment the water quality is very good,

displaying low salinity, turbidity and nutrients such as phosphorus. Over time the macroinvertebrate

invertebrate surveys indicate the waterway to range from healthy to being moderately to mildly

impacted, this is likely due to reduced native riparian vegetation. Further down the catchment in the

rural farmlands of the plains some declines in water quality are evident at several sites, this is further

supported by the generally poor macroinvertebrate communities present at the sites surveyed.

Greatly reduced native riparian vegetation and even complete removal of vegetation has happened

in the past. Removal of this vegetation and replacement with willows at many sites also occurred in

the past.

For the Barwon River the water quality has varied over time, rainfall in the catchment transports

sediments into the river, particularly from the small intermittent streams that flow from the Otway

Ranges such as Pennyroyal and Mathews Creeks. Unrestricted stock access and greatly reduced

riparian vegetation along these streams severely degrades these waterways. Increases in salinity

also occur in these streams at times of no river flow and may be impacted by the ingression of saline

ground water into pools.

A notable increase in nutrients such as phosphorus is also evident and likely linked to farming

practices in the area and imported to waterways attached to soil particles, when this makes its way

into the waterways it has the potential to increase the growth of aquatic plants and even stimulate

algal blooms. This in effect alters the dissolved oxygen levels in the water. During daytime, as a

product of photosynthesis, oxygen levels increase at time to supersaturation levels (> 110 %

saturation). This can be harmful to aquatic organisms such as fish. During the night when plants are

not photosynthesising the dissolved oxygen levels can drop to extremely low levels and can also be

22

harmful to aquatic life. Daytime high dissolved oxygen levels were also recorded in the Barwon River

particularly over the warmer months indicating potential algal growth in the water.

Low pH levels had been recorded at several sites in the upper Barwon River, these low levels may

indicate acid sulphate soils in the catchment. Boundary Creek displays a waterway significantly

impacted by acidic conditions, as this flows into the Barwon River it is likely to have an impact.

CCMA Actions in the Upper Barwon landscape zone

The Corangamite Catchment Management Authority has set management activities in the Upper

Barwon landscape zone to address water quality threats in the area (Table 9), for further information

see CCMA Corangamite Waterways Strategy 2014 - 2022.

Table 9. CCMA management activities to address water quality threats in the Upper Barwon landscape zone.

Corangamite Waterway Strategy Priority Actions Barwon River and tributaries

Establish native indigenous vegetation

Barwon River, Retreat Creek, Penny Royal Creek, Dewing Creek, Barwon River East Branch and Boundary Creek

Install riparian/wetland fencing


Establish stewardship/management agreement


Establish non-woody and/or woody weed control Barwon River, Penny Royal Creek, Barwon River East Branch and Boundary Creek

Undertake an assessment and management of fish barriers in the Barwon and Moorabool catchments

Barwon River, Retreat Creek, Penny Royal Creek, Barwon River East Branch and Boundary Creek

Establish invasive species assessment and management Barwon River East Branch

Undertake stabilisation works downstream of Cape Otway Rd

Retreat Creek

Above: Monitoring site CO_BAR010 in the upper catchment. Photo Corangamite CMA

23


Implement best management practice on grazing properties

Barwon River

Undertake an assessment of instream habitat (large wood) density

Barwon River

Investigate potential processes impacting acid sulfate soil issues and methods to minimise further risk

Boundary Creek

Implement the Central Region Sustainable Waterway Strategy action for Upper Barwon environmental entitlement including the development of long-term planning for environmental watering of the Barwon Rive (EWMP)

Barwon River, Barwon River West Branch and Barwon River East Branch

Investigate impacts to environmental flows and (where required) identify opportunities to secure and better manage environmental water

Penny Royal Creek, Dewing Creek and Barwon River East Branch

Conduct monitoring and maintenance to ensure that waterway remains in current condition

Barwon River West Branch and Dewing Creek

Comply with bulk entitlements, monitor and maintain waterway condition and implement risk management plans as appropriate

West Barwon Dam

Maintain Waterwatch groups collecting baseline data on waterway condition

All Waterwatch sites

24

The Mid-Barwon landscape zone

The mid reaches of the Barwon River flow through the Mid-Barwon landscape zone. These reaches

actually commence at the Upper Barwon landscape zone near Birregurra, and flow through the Mid-

Barwon landscape zone near Winchelsea and to Fyansford near Geelong in the east. There are

numerous tributaries feeding into the Barwon River in this zone, including Native Hut and Bruce’s

creeks. There are 703 km of rivers and streams in the landscape zone. This is a productive

agricultural region accounting for 89% of land use.

Significant water bodies in the Mid-Barwon landscape zone include the Wurdiboluc Reservoir, which

supply potable water to Geelong, Anglesea, Torquay and the Bellarine Peninsula

During the development of the Corangamite Waterway Strategy 2014 – 2022 the Mid Barwon

communities identified the following key values their waterways provide:

• support for biodiversity including many species of fish and birds, as well as remnant native


• confined valleys with intrinsic environmental value

• numerous opportunities for recreation including picnic sites, swimming holes, fishing and four

wheel driving

• consistent use of the waterways across the landscape for stock watering and other agricultural

activities.

Citizen science projects conducted in the Mid Barwon landscape zone:

• Platypus eDNA Monitoring Project 2019 – 1 eDNA site that is also a regularly monitored

Waterwatch site

• The Pesticide Detectives – 1 site

• The National Waterbug Blitz – 1 site

Community Groups active in the Mid Barwon landscape zone that have contributed to data

collection:

• The Geelong Landcare Network

• Barrabool Hills Landcare and Batesford Fyansford Stonehaven Landcare

A total of six monitoring sites are assessed in the Mid Barwon landscape zone (Figure 12).

25


Over the assessment period (2005 – 2020), the water quality in the Mid-Barwon landscape zone

displayed similar trends across sites on the Barwon River. The most downstream site CO_BAR100

at Buckleys Falls displayed the best water quality.

Figure 12. The location of sites represented as yellow dot with the site code in the Mid-Barwon landscape

zone. (Map sourced from CCMA CWS 2013)

26

Downstream from site CO_BAR040 (Upper Barwon landscape zone) is site CO_BAR060, at this site

electrical conductivity was mostly under 2000 µS/cm and the pH ranged from 5.4 to 8.6 pH units, two

low values (< 6.5 pH units) were recorded in 2016 (5.4 pH units) and 2018 (6.2 pH units). Dissolved

oxygen levels ranged from 22% to 161% saturation, the lower dissolved oxygen levels (< 50%

saturation) often occurred at times of lower electrical conductivity suggesting increased flows at

these times deliver organic matter to the river channel increasing the instream oxygen demand. High

dissolved oxygen levels were recorded on two occasions in 2019 (131% and 161% saturation)

indicating potential excessive algal growth (Figure 13). The turbidity ranged from 0 to 234 NTU, high

values were recorded at times of increased river flows. Reactive phosphate ranged from 0

(undetectable) to a high 0.28 mg/L, indicating this site experiences high levels of reactive phosphate

at times which can result in excessive macrophytes and algal growth.

Just downstream, at site CO_BAR062 monitoring commenced in late 2017, only electrical

conductivity and pH is monitored at this site. Increases in electrical conductivity occurred over

summer at times of low river flow, the highest being 4,800 µS/cm in 2018, the pH remained in the

healthy range.

The next site downstream CO_BAR070 is just upstream of the confluence with the Yarrawee –

Leigh River. The water quality indicators follow a similar pattern as the two upstream sites. Electrical

conductivity ranged from 630 to 4800 µS/cm being slightly higher than the previous site. Seasonal

trends of higher electrical conductivity over summer are evident. The pH ranged from 6.6 to 9.0 pH

units, and was mostly at healthy levels. The dissolved oxygen ranged from 25% to 146% saturation,

high levels occurred in 2006 (145% saturation) and 2017 (146% saturation) indicating potential algal

growth, low levels also occurred regularly (Figure 14). Turbidity ranged from 0 to 187 NTU, with

increases occurring when electrical conductivity was low, suggesting increased river flow. Reactive

phosphate ranged from 0 to a high 0.55 mg/L. High values generally occurred from late summer to

autumn (Figure 14). At site CO_BAR080 electrical conductivity ranged from 630 to 3600 µS/cm, as

with the previous sites higher levels occurred over the summer to autumn seasons. The pH ranged

from 5.9 to 9.1 pH units, with higher levels occurring during times of high dissolved oxygen (Figure

15) at these times ammonia levels may also increase, ammonia can be toxic to aquatic organisms.

The dissolved oxygen ranged from 37% to 150% saturation, high values were recorded over the

summer to autumn seasons suggesting excessive macrophytes of algal growth during these times.

Turbidity ranged from 0 to 270 NTU, as with the previous site high turbidity generally occurs with

Figure 13. Site CO_BAR060 displaying the dissolved oxygen and turbidity from 2005 to 2020.

27

increased river flow. Reactive phosphate ranged from 0.00 - 0.45 mg/L. High values also occurred at

times of increased flow.

Further downstream near Geelong below Buckley Falls at site CO_BAR100 from 2014 to 2020 electrical conductivity ranged from 720 to 3030 µS/cm, as with the previous sites higher levels occurred over the summer to autumn seasons. The pH ranged from 7.0 to 8.3 pH units, maintaining healthy levels. The dissolved oxygen ranged from 53% to 189% saturation, one extremely high value was recorded (189% saturation) in January 2018 season suggesting excessive macrophytes of algal growth during this time. Turbidity ranged from 9 to 80 NTU, as with the previous site high turbidity generally occurs with decreased electrical conductivity as a result of increased river flow. Reactive phosphate ranged from 0.015 to 0.28 mg/L higher values are observed mostly during times of low electrical conductivity (Figure 16).

Figure 14. Site CO_BAR070 displaying the dissolved oxygen and reactive phosphate from 2005 to 2020.

Figure 15. Site CO_BAR080 displaying the dissolved oxygen and pH from 2005 to 2020.

28

Site CO_BRU100 on Bruce Creek a tributary of the Barwon River with intermittent flow, the

confluence with the Barwon River is upstream of site CO_BAR080.

Monitoring commenced in 2015 with only 15 monitoring events recorded. The electrical conductivity

ranged from 270 to 10,700 µS/cm, the high values suggests ingression of saline ground water

(Figure 17). The pH ranged from 7.2 to 8.0 pH units, maintaining healthy levels. The dissolved

oxygen ranged from 10% to 91% saturation, one extremely low value was recorded (10% saturation)

in summer 2019. Turbidity ranged from 9 to 150 NTU, the high turbidity was the result of recent

rainfall in the catchment. Reactive phosphate ranged from 0.01 to 0.43 mg/L higher values were

observed during times of low electrical conductivity.

Figure 16. Site CO_BAR0100 displaying the reactive phosphate and electrical conductivity from 2014 to 2020.

Figure 17. Site CO_BRU100 displaying the dissolved oxygen and electrical conductivity from 2015 to 2020.

29


Sites on the Barwon River in the Mid-Barwon landscape zone

The water quality in the Mid-Barwon landscape zone met some of the SEPP (Waters) environmental

water quality objectives, indicating beneficial may be at risk (Table 10).

• All sites met the upper and lower objectives for pH with the exception site CO_BAR080 (8.20

pH units).

• Sites CO_BAR060, CO_BAR062 and CO_BAR100 met the electrical conductivity (75th

percentile < 2000 µS/cm) objective, whilst sites CO_BAR070 (2300 µS/cm), CO_BAR080

(2200 µS/cm) and the tributary site CO_BRU100 (6,700 µS/cm) exceeded the objective.

• All sites exceeded the dissolved oxygen maximum objective except site CO_BRU100 (91%

saturation), limited sampling at this site may not have identified times of extremely high

dissolved oxygen.

• Two sites CO_BAR080 and CO_BAR100 met the lower dissolved oxygen objective (25th

percentile ≥ 70% saturation) whilst sites CO_BAR060 (60% saturation), CO_BAR070 (62%

saturation) and site CO_BRU100 (43% saturation) were below the objective.

• Three sites, CO_BAR070, CO_BAR080 and CO_BAR100 met the turbidity objective (75th

percentile ≤ 25 NTU) whilst sites CO_BAR060 (26 NTU) and CO_BRU100 (30 NTU)

exceeded the objective.

• Only one site CO_BAR060 met the total phosphorus objective (75th percentile ≤ 0.06 mg/L)

whilst sites CO_BAR070 (0.08 mg/L), CO_BAR080 (0.104 mg/L), CO_BAR100 (0.07 mg/L)

and CO_BRU100 (0.08mg/L) exceeded the objective.

Table 10. Water quality assessment against State Environment Protection Policy (Waters) for sites in the Mid

Barwon landscape zone. (Blue and green indicate objective is met, benificial uses are protected, orange and

red indicate objective is not met, benificial uses may be at risk).




Turbidity (NTU)

Reactive Phosphate

(mg/L)


CO_BAR060 148 60 161 1580 7.10 7.60 26 0.036

CO_BAR062 37 NA NA 1571 7.00 7.00 NA NA

CO_BAR070 152 62 146 2300 7.40 7.80 23 0.080

CO_BAR080 151 74 150 2200 7.70 8.20 13 0.104

CO_BAR100 65 78 189 1833 7.50 8.00 20 0.070

CO_BRU100 15 43 91 6700 7.60 7.85 30 0.080

Aquatic macroinvertebrate assessment in the Mid-Barwon landscape zone

Aquatic macroinvertebrate monitoring was undertaken at four sites in the Mid Barwon Landscape

Zone over the assessment period (Table 11). Two surveys were conducted at site CO_BAR060 the

weighted SIGNALT score indicate the site was moderately impacted in 2017 and heavily impacted in

2018. At site CO_BAR080 one survey in 2015 indicate the site to be heavily impacted, whilst

improvements occur downstream at site CO_BAR100. The score indicated the site to be

moderately impacted in 2018 and mildly impacted in 2015 and 2019. The site on the Bruce Creek

tributary was monitored as part of the National Waterbug Blitz in 2019 on this occasion the score

indicated the site to also be heavily impacted.

30

Table 11. Results of macroinvertebrate surveys in the Mid-Barwon landscape zone from 2005 to 2020.

Site Date Method Weighted SIGNALT score

CO_BAR060 2 May 2017 ALT 3.5

12 April 2018 Order 1.2

CO_BAR080 14 January 2015 ALT 3.0

CO_BAR100 25 November 2015 ALT 4.0

28 February 2018 Order 3.4

4 April 2019 ALT 3.8

CO_BRU100 Dec 2019 NWB ALT 2.8

Summary of the Mid-Barwon landscape zone

As the Barwon River flows from the upper catchment into the mid reaches from Winchelsea through

the rural farmlands of the plains to Geelong the water source from the Leigh River provides

additional flow. However, some decline in some water quality indicators are evident. Increases in

salinity and phosphorus occur in a downstream direction and can be partially attributed to inflow

from the Leigh River (see next section). All sites experience either excessive macrophyte or algal

growth particularly over the summer and autumn seasons potentially creating dissolved oxygen

peaks and troughs. This is supported by the macroinvertebrates present, the majority being pollution

tolerant indicating the waterway to be moderately to heavily impacted. Reduced native riparian

vegetation and even complete removal of vegetation and lack of instream aquatic habitat and

unrestricted stock access all impact on the water quality and the aquatic organisms present.

As the Barwon River enters the city of Geelong the water quality is reasonably healthy for a lowland

river with the exception of phosphorus levels which are likely to stimulate algal blooms over the

warmer seasons, the macroinvertebrate community supports this displaying mild impacts.

The Bruce Creek tributary of the Barwon River highlights an area of saline ground water intrusion

particularly during times of low river flows, the electrical conductivity at this site far exceeds the

SEPP (Waters) objectives and is also a possible source of sediment as indicated by high turbidity

levels. The macroinvertebrate community indicate the site is heavily impacted.

CCMA Actions in the Mid-Barwon landscape zone

The Corangamite Catchment Management Authority has set management activities in the Mid

Barwon landscape zone to address water quality threats in the area (Table 12), for further

information see CCMA Corangamite Waterways Strategy 2014 - 2022.

Table 12. CCMA management activities to address water quality threats in the Mid Barwon landscape zone.


Establish terrestrial pest animal control – rabbit control Barwon River


Barwon River

Native Hut Creek

Install riparian fencing

Barwon River

Native Hut Creek


Barwon River

Native Hut Creek

31

Establish non-woody and/or woody weed control Barwon River, Penny Royal Creek, Barwon River East Branch and Boundary Creek


Barwon River

Native Hut Creek

Establish invasive species assessment and management Barwon River East Branch

Investigate stream instabilities Native Hut Creek


Barwon River


Barwon River

Investigate and manage urban stormwater/water quality impacts in line with whole of water cycle management principles

Barwon River

Implement the Barwon through Geelong Management Plan and Barwon River Parklands Strategy

Barwon River


Wurdiboluc Reservoir



Above: The Barwon River at site CO_BAR070. Photo Corangamite CMA

32

The Leigh landscape zone

The Leigh landscape zone is located between the Woady Yaloak and Moorabool landscape zones

and stretches from Ballarat in the north to Inverleigh in the south. The Yarrowee-Leigh River system

is a highly modified and regulated waterway with parts of the upper reaches traversing urban

landscapes through Ballarat as well as containing water storages for urban and rural use and

sewage treatment plant and gold mine discharges. The Yarrowee-Leigh river system is the principle

source of water for the area and feeds into the Barwon River at Inverleigh. Flow deviation through

major headworks to supply urban water has altered both the quantity and quality of natural flows.

Additionally, the Leigh River system is a major tributary to the Barwon River. As such, its changed

flow regimes can impact the health of the lower Barwon River, including Lake Connewarre and

Reedy Lake.

There are 1,689 km of rivers and streams in the landscape zone. Significant water bodies include

Lake Wendouree, listed on the Directory of Important Wetlands in Australia, and White Swan and

Gong Gong reservoirs, which supply water to the city of Ballarat and surrounding communities.

Agriculture accounts for 73% of land use in the region.

Ballarat and the region have a rich gold mining history which includes the gold rush period during the

mid to late 1800s. This gold rush had a major impact on the health of the Yarrowee and Leigh rivers

leading to increased erosion of river bed and banks. Part of the Yarrowee River flows through

Ballarat’s central business district and was placed underground through a bluestone-lined channel.

Williamsons Creek joins the Yarrowee near Mt Mercer, downstream the Yarrowee is named the

Leigh River.

During the development of the Corangamite Waterway Strategy 2014 – 2022 the Leigh River




• confined valleys with spectacular scenery with intrinsic environmental value, and its

associated reaches that include parks, picnic sites, lookouts, swimming holes, fishing and

camping spots and historic bridges

• Numerous opportunities for recreation including walking, swimming, camping, fishing boating

and kayaking


activities.

Citizen science projects conducted in the Leigh landscape zone:

• The Pesticide Detectives - 2 sites

Community Groups active in the Leigh landscape zone that have contributed to data collection:

• Leigh Catchment Group

• Grenville, Napoleons/Enfield and Garibaldi Landcare groups.

A total of eight monitoring sites are assessed in the Leigh landscape zone for this project (Figure

18).

33

Figure 18. The location of sites represented as yellow dot with the site code in the Leigh landscape zone. (Map sourced from CCMA CWS 2013)

34


Over the assessment period (2005 – 2020) there was limited water quality monitoring in the Leigh

landscape zone. Located in the township of Ballarat at the headwaters of the Yarrowee – Leigh

River, Lake Wendouree and its wetland have five of the eight monitoring sites in this landscape

zone. Two of the remaining sites are on the Leigh – Yarrowee River and one is on Williamsons

Creek a tributary.

Lake Wendouree and the northern wetland

Site CO_LNW200 in the northern wetland was monitored regularly from mid-2015 to early 2018.

The water quality monitoring at sites in Lake Wendouree were undertaken during biannual

macroinvertebrate surveys and therefore will be analysed separate from the riverine sites. Table 13

displays the measurements recorded during each macroinvertebrate surveys.

Site CO_LNW200 in the northern wetland is stormwater fed and leads to Lake Wendouree, the

highest electrical conductivity recorded in the wetland was 2640 µS/cm, higher than any time in Lake

Wendouree and the lowest electrical conductivity was 115 µS/cm. In comparison, electrical

conductivity ranged from 1000 µS/cm to 1888 µS/cm in Lake Wendouree. Monitoring in Lake

Wendouree may not have been performed at times of high electrical conductivity.

The pH within Lake Wendouree and the wetland ranged from 6.4 pH units at site CO_LWN040 and

6.5 pH units in the wetland site CO_LNW200 (Figure 19) to 9.5 pH units at site CO_LWN060 and

9.2 pH units at site CO_LWN050. The lowest pH value recorded at site CO_LWN060 (8.9 pH units)

indicates Lake Wendouree may be at risk of increased ammonia levels which can be toxic to aquatic

organisms.

Dissolved oxygen levels varied mostly in the wetland ranging from 31% to 124% saturation (Figure

20). High dissolved oxygen levels may indicate excessive macrophyte or algal growth. Within Lake

Wendouree dissolved oxygen levels ranged from 47% saturation at site CO_LWN040 to 106%

saturation at site CO_LWN060.

Figure 19. Site CO_LNW200 displaying the pH and turbidity from 2015 to 2018.

35

The highest turbidity was also recorded in the northern wetland (32 NTU) as would be expected for

the inlet to Lake Wendouree. All sites in Lake Wendouree displayed low turbidity (< 10 NTU) with the

exception of site CO_LWN070 (15 NTU) indicating most of the time the water is clear.

The reactive phosphate levels were also highest in the wetland with concentration of 0.14 mg/L

being recorded. High reactive phosphate levels may lead to nuisance algal growth or excessive

macrophytes growth. Within Lake Wendouree reactive phosphate levels remained fairly low ranging

from 0.01 to 0.04 mg/L.

How did the water quality in Lake Wendouree and the northern wetland compare to SEPP

(Waters) environmental water quality objectives?

Sites on Lake Wendouree in the Leigh landscape zone

The water quality in the northern wetland site CO_LNW200 (Table 13) met the objectives for pH,

turbidity and the adapted objective for electrical conductivity. The reactive phosphate levels

exceeded the total phosphorus objective. Dissolved oxygen levels marginally exceeded both

objectives.

Table 13. Water quality assessment against SEPP (Waters) for the northern wetland site CO_LNW200. (Blue

and green indicate objective is met, beneficial uses are protected, orange and red indicate objective is not

met, beneficial uses may be at risk).




Turbidity (NTU)

Reactive Phosphate

(mg/L)

Site Code Sample Count

25th% Max 75th% 25th% 75th% 75th% 75th%

CO_LNW200 30 68 124 1100 7.50 8.00 15 0.110

The water quality in Lake Wendouree met some of the SEPP (Waters) environmental water quality

objectives, indicating beneficial uses may be at risk (Table 14). At any one time of monitoring varied

levels of indicators were observed.

Figure 20. Site CO_LNW200 displaying the pH and turbidity from 2015 to 2018.

36

Table 14. Water quality measurements and assessment against SEPP (Waters) from macroinvertebrate

surveys for sites in Lake Wendouree including weighted SIGNALT score. (Blue and green indicate objective

is met, beneficial uses are protected, orange and red indicate objective is not met, beneficial uses may be at

risk).

CO_LWN040 Dissolved Oxygen % Saturation


(µS/cm)

pH (pH units)

Reactive Phosphate

(mg/L)

Turbidity (NTU)

Weighted SIGNALT

score

22/04/2015 71.88 1420 8.4 0.02 0.71 3.3

27/10/2015 81 1340 8.5 0.01 2.83 2.8

13/04/2016 64.13 1808 7.9 0.007 3.62 2.4

10/10/2016 65 1001 7.7 0.03 5.96 3.1

20/04/2017 NA 1369 8.8 0.013 7.85 3.1

8/11/2017 70.7 1310 8.6 0.02 1.78 2.6

10/04/2018 60.52 1671 8.1 0.015 4.85 2.2

22/11/2018 91.51 1616 NA 0.03 6.76 3.2

10/04/2019 46.65 1656 6.4 0.03 4.68 3.1

6/11/2019 105.84 1434 7.1 0.04 3 3.3

CO_LWN050

22/04/2015 79.21 1430 9.1 0.003 2 3.2

11/11/2015 78 1395 9.2 0.007 2.21 3.0

13/04/2016 102.72 1775 9.1 0.013 1.85 2.6

10/10/2016 83 1091 8.6 0.02 4.13 3.7

20/04/2017 74.7 1381 8.9 0.01 3.7 3.8

15/11/2017 82.23 1402 8.7 0.01 1.89 2.8

10/04/2018 92.39 1744 7.9 0.015 2 3.8

15/11/2018 97.73 1571 NA 0.03 3.34 4.0

12/04/2019 93.21 NA 8.9 0.03 2.69 4.1

CO_LWN060

8/04/2015 96.3 1440 9.4 0.01 1.35 3.8

11/11/2015 91 1513 9.3 0.01 1.45 4.0

13/04/2016 95.71 1772 9.2 0.007 1.72 3.4

12/10/2016 85 1110 9.1 0 4.33 3.5

20/04/2017 94.62 1380 9.5 0.013 2.05 3.6

8/11/2017 79.35 1338 8.9 0.01 2.61 4.1

9/04/2018 106.16 1797 9.3 0.03 1.55 3.7

22/11/2018 85.73 1655 8.9 0.03 1.69 3.8

10/04/2019 78.15 1659 9.3 0.03 2.55 4.3

CO_LWN070

8/04/2015 62.23 1440 7.9 0.01 4.55 3.8

27/10/2015 53 1400 7.9 0.02 4.47 3.2

14/04/2016 74.91 1840 8 0.015 15 3.0

10/10/2016 96 1041 8.1 0.04 6.62 2.9

20/04/2017 86.64 1359 8.7 0.03 4.32 2.4

15/11/2017 103.61 1353 9 0.03 5.05 2.1

10/04/2018 83.08 1888 8.3 0.03 2.49 3.0

15/11/2018 100.36 1587 NA 0.015 8 3.2

12/04/2019 NA NA NA NA NA 2.6

37

All sites displayed lower electrical conductivity than the adapted objective (75th percentile < 2000

µS/cm). All sites displayed lower reactive phosphate than the objective (75th percentile 0.10 mg/L).

All sites also met the objective for turbidity (75th percentile ≤ 15 NTU). All sites except site

CO_LWN040 (Min. 6.40 pH units) met the lower pH objective (25th percentile 6.50 pH units) whilst

three sites CO_LWN050 (Max 9.20 pH units), CO_LWN060 (Max 9.50 pH units) and CO_LWN070

(Max 9.00 pH units) exceeded the upper pH objective (75th percentile ≤ 8.5 pH units) on many

occasions. All sites met the upper dissolved oxygen objective (max. 120% saturation), however sites

only met the lower dissolved oxygen objective (25th percentile ≥ 80% saturation) in some years.

Aquatic macroinvertebrate assessment

The macroinvertebrate community composition at all sites indicated the lake is impacted (Table 14).

The weighted SIGNALT scores indicate sites CO_LWN060 and CO_LWN050 to mostly be mildly

impacted whilst sites CO_LWN040 and CO_LWN070 to be moderately to heavily impacted.

Riverine sites of the Leigh Landscape Zone

Only two sites are monitored on the Yarrowee - Leigh River, water quality monitoring was mostly

undertaken during macroinvertebrate surveys and will be assessed independently. One site is on a

tributary and has routine water quality monitoring.

Site CO_YAR050


On the urban fringe of Ballarat is site CO_YAR050, water quality monitoring was generally

undertaken during macroinvertebrate surveys from 2014 to 2018, additional monitoring was

conducted in 2016. At the site electrical conductivity ranged from 700 to 1820 µS/cm and pH ranged

from 6.8 to 7.5 pH units remaining within the healthy range (Table 15). The dissolved oxygen levels

ranged from 53% to 118% saturation, low dissolved oxygen (<60%) was observed on two occasions.

Low dissolved oxygen levels can impact of aquatic fauna. The turbidity levels ranged from 6 to 35

NTU. The majority of the time the turbidity levels were low (< 10 NTU). Reactive phosphate levels

ranged from 0.00 (undetectable) to 0.08 mg/L.

Table 15. Water quality measurements from macroinvertebrate surveys and assessment against SEPP

(Waters) for site CO_YAR050. (Blue and green indicate objective is met, beneficial uses are protected, orange

and red indicate objective is not met, beneficial uses may be at risk).

Date Dissolved Oxygen % Saturation


(µS/cm)

pH (pH units)

Reactive Phosphate

(mg/L) Turbidity (NTU)

20/05/2014 NA 1230 7.5 0 10

28/04/2015 98 880 7 0.03 10

24/11/2015 78.23 1514 7.4 0.053 11.32

14/12/2015 118 1820 7.5 0.015 35

25/01/2016 53 700 7.5 0.045 10

28/02/2016 75 1220 7.5 0.015 10

2/05/2016 NA 749 7.5 0.013 25

23/05/2017 NA 1046 7.5 0.03 10

28/03/2018 54.85 850 6.8 0.045 8.38

5/10/2018 86.36 741 7.5 0.08 6.03

26/10/2018 91 NA NA NA NA

38

As only ten monitoring events are assessed all values have been used to compare with SEPP

(Waters) environmental quality objectives (Table 15). Site CO_YAR050 met the SEPP (Waters)

objectives for electrical conductivity, pH, and dissolved oxygen maximum, and exceeded the

turbidity objective (< 15 NTU) on two occasions (December 2015 and May 2016), total phosphorus

on one occasion (October 2018) and lower dissolved oxygen on two occasions (January 2016 and

March 2018). Indicating beneficial are mostly protected.


Macroinvertebrate monitoring was undertaken on five occasions (Table 16). The weighted SIGNALT

scores indicate the site to be heavily impacted in autumn 2015 and in spring 2017, moderately

impacted in autumn 2016 and mildly impacted in autumn 2017 and spring 2018.

Table 16. Results of macroinvertebrate surveys at site CO_YAR050.

Date Method Weighted SIGNALT score

28 April 2015 ALT 2.5

2 May 2016 Order 3.2

23 May 2017 ALT 3.6

21 August 2017 Order 3.0

26 October 2018 ALT 3.7

Site CO_YAR215


Descending the Yarrowee-Leigh River to site CO_YAR215 water quality monitoring was undertaken

from 2016 to 2019. At the site electrical conductivity ranged from 400 to 1300 µS/cm, the pH ranged

from 7.00 to 8.00 pH units, and the dissolved oxygen levels ranged from 70% to 113% saturation

(Table 17). The turbidity ranged from 10 to 60 NTU, the turbidity levels were mostly very low with

only two monitoring events recording turbidity of 30 and 60 NTU. Reactive phosphate levels

fluctuated ranging from 0.06 to 0.7 mg/L, the high levels observed at this site are extreme and may

lead to excessive macrophytes growth or algal growth.

Table 17. Water quality measurements from macroinvertebrate surveys and assessment against SEPP

(Waters) for site CO_YAR215. (Blue and green indicate objective is met, beneficial uses are protected, orange

and red indicate objective is not met, beneficial uses may be at risk).

Date Dissolved Oxygen % Saturation


(µS/cm)

pH (pH units)

Reactive Phosphate

(mg/L) Turbidity (NTU)

10/11/2016 69.51 1200 8 0.11 10

21/12/2016 101.73 1300 8 0.08 10

24/02/2017 78.64 1000 8 NA 10

25/02/2017 72 1000 7.5 NA 10

27/03/2017 78.45 1200 7.5 0.7 10

13/05/2017 78.26 1200 7.5 0.55 10

17/09/2017 75.42 800 7 0.06 30

27/11/2017 78.49 400 7 0.14 60

4/04/2018 112.8 1076 8 0.7 10

20/11/2019 NA 984 NA NA NA

39

As only ten monitoring events are assessed all values have been used to compare with SEPP

(Waters) environmental quality objectives (Table 17). Site CO_YAR215 met the SEPP (Waters)

objectives for electrical conductivity, pH, and dissolved oxygen maximum, and exceeded the

turbidity objective (< 15 NTU) on two occasions (September and November 2017), total phosphorus

on all occasions and lower dissolved oxygen on one occasion (November 2016). Indicating

beneficial uses may be at risk due to excessive phosphorus levels.


Macroinvertebrate monitoring was undertaken on one occasion (Table 18). The weighted SIGNALT

score indicated the site to be mildly impacted in 2019.

Table 18. Results of macroinvertebrate surveys at site CO_YAR215.


20 November 2019 ALT 4.6

CO_WIL010 Williamsons Creek


The most downstream site assessed is on a tributary of the Yarrowee- Leigh River. Williamsons

Creek site CO_WIL010 is an intermittent waterway displaying relatively poor water quality. Electrical

conductivity ranged from 180 to 6840 µS/cm (Figure 21), the high electrical conductivity suggests at

times of low or no river flow ingression of saline groundwater occurs. The pH ranged from 6.7 to 9.3

pH units, high pH can lead to increased ammonia toxicity for the aquatic organisms (Figure 21). The

dissolved oxygen also varied ranging from 20% to 102% saturation, low dissolved oxygen levels can

also be lethal to aquatic fauna. Turbidity ranged from 9 to 180 NTU, suggesting at times there is

increased sediment movement at this site. Reactive phosphate levels ranged from 0.01 to 0.55 mg/L

indicating very high levels of phosphorous entering this waterway at times.

Site CO_WIL010 exceeded all of the SEPP (Waters) environmental water quality objectives (Table

19) with the exception of the upper dissolved oxygen objective (max. 130% saturation) and the lower

pH objective (25th percentile, 6.80 pH units) indicating the beneficial uses are likely to be at risk of

Figure 21. Site CO_WIL010 displaying the pH and electrical conductivity from 2005 to 2019.

40

poor water quality. The Williamson Creek site was impacted by the Scotsburn fires on 19th

December 2015, however, no impacts eg. increase in turbidity on water quality were observed in the

short or long term.

Table 19. Water quality assessment against SEPP (Waters) for site CO_WIL010 in the Leigh Landscape Zone.

(Blue and green indicate objective is met, benificial uses are protected, orange and red indicate objective is

not met, benificial uses may be at risk).

Dissolved Oxygen % Saturation



Turbidity (NTU)

Reactive Phosphate

(mg/L)

Site Code 25th% Max 75th% 25th% 75th% 75th% 75th%

CO_WIL010 50 102 2315 7.80 8.40 20 0.140


Macroinvertebrate monitoring was undertaken on 13 occasions from 2005 to 2018 (Table 20). The

weighted SIGNALT scores indicated the site to be heavily impacted in spring 2005, 2006 and 2015,

moderately impacted in autumn 2012, winter 2014, summer 2015 and autumn 2017, and mildly

impacted in winter 2010, autumn and summer 2013 and spring 2017 and 2018.

Table 20. Results of macroinvertebrate surveys at site CO_WIL010.


20 October 2005 Order 3.0


1 July 2010 Order 3.7

11 May 2012 Order 3.2


7 December 2013 Order 4.3


2 February 2015 ALT 3.3

5 August 2015 ALT 3.0


17 April 2017 ALT 3.4


16 September 2018 Order 3.8

Summary of the Leigh landscape zone

Lake Wendouree is an urban constructed lake that receives stormwater runoff from the regional

town of Ballarat. On most occasions the water quality was reasonably healthy displaying low salinity,

turbidity and phosphorus, oxygen levels within the lake often varied between sites and sampling

events though was mostly healthy. At some sites variable oxygen levels were observed likely

associated with aquatic vegetation. Oxygen levels in waterways with an abundance of aquatic

vegetation often display diurnal fluctuations as a result of photosynthesis, therefore results are likely

influenced by the time of day when monitoring occurred. At the times of monitoring (biannual - spring

and autumn) high pH levels (> 9 pH units) were observed at several sites (CO_LWN050 and

CO_LWN060). The high pH is likely due to excessive aquatic plant or algal growth decreasing the

CO2 levels during photosynthesis. Increases in pH in water increases ammonia toxicity and can be

toxic to aquatic life if an abundance of nitrogen is present. Low dissolved oxygen levels were also

41

observed and are likely due to the consumption of oxygen by oxygen dependant organisms and

microbial decay of organic matter. The macroinvertebrate community suggest the lake to be mildly to

heavily impacted, though the scoring system was developed for rivers and does not fit as well in

wetlands and lakes.

Limited data was available for the Yarrowee – Leigh River, both sites are in the upper catchment

one upstream (CO_YAR050) and one downstream (CO_YAR215) of Ballarat. The water quality of

site CO_YAR050 was mostly healthy, though at times displayed low dissolved oxygen and high

turbidity. The site lacks native riparian vegetation and instream cover for aquatic organisms. The

macroinvertebrate community indicate the site to be mildly to heavily impacted.

The water quality of site CO_YAR215 was mostly healthy however phosphorus levels were high,

high levels can stimulate excessive aquatic plant and algal growth which may impact on the

beneficial uses. The riparian vegetation and aquatic habitat are degraded at this site and the

macroinvertebrate community suggest the site is mildly impacted.

The Williamsons Creek, at tributary of the Yarrowee – Leigh River displayed relatively poor water

quality. This intermittent stream exceeded most of the SEPP (Waters) water quality objectives. High

electrical conductivity levels at times indicate the ingression of saline groundwater at times of low or

no flow. The macroinvertebrate community indicate the site to be mildly to heavily impacted, in times

of increased river flow (low electrical conductivity) more sensitive macroinvertebrate communities

are present.

Above: Citizen scientists monitoring the water quality in Lake Wendouree at site CO_LWN060. Photo Corangamite CMA

42

CCMA Actions in the Leigh landscape zone

The Corangamite Catchment Management Authority has set management activities in the Leigh

landscape zone to address water quality threats in the area (Table 21. CCMA management activities to address water quality threats in the Leigh landscape zone., for further


Table 21. CCMA management activities to address water quality threats in the Leigh landscape zone.



Leigh River

Yarrowee River

Williamson Creek


Leigh River

Yarrowee River

Williamson Creek


Leigh River

Yarrowee River

Williamson Creek

Undertake woody weed control Yarrowee River

Williamson Creek

Lake Wendouree


Yarrowee River

Maintain the function of an urban wetland Lake Wendouree

Maintain the discharge into the Yarrowee Leigh from South Ballarat Treatment Plant as a beneficial environmental use – as per the Central Region Sustainable Water Strategy, and examine opportunities to better replicate natural flow regimes

Leigh River

Yarrowee River

Adopt whole of water cycle management principles to reduce the impact of stormwater run-off on the health of Yarrowee Leigh and downstream waterways

Yarrowee River

Enhance the upstream reach in line with the Breathing Life back into the Yarrowee Project

Yarrowee River


White Swan Reservoir

Gong Gong Reservoir



43

The Moorabool landscape zone

The Moorabool landscape zone is located in the north-east of the region and stretches from

Fyansford on the outskirts of Geelong in the south to the top of the Moorabool River basin east of

Ballarat in the north. The main source of water is the Moorabool River and its tributaries, which then

flow into the Barwon River at Fyansford.

There are 2,151 km of rivers and streams in the landscape zone. The Moorabool River is highly

regulated containing a number of water storages and weirs, the largest being Lal Lal Reservoir,

which provides water for Ballarat as well as Geelong and Meredith. Agriculture accounts for 96% of

land use in the region. Key issues for waterway management include reduced river flow and legacy

issues from past waterway practices. Recent assessment of environmental flows in the Moorabool

River identified the following ecological objectives:

• maintaining the diversity and abundance of macroinvertebrates

• minimising likelihood of low DO and elevated EC during low flow periods

During the development of the Corangamite Waterway Strategy 2014 – 2022 the Moorabool River




• confined valleys with spectacular scenery with intrinsic environmental value, and its

associated reaches that include parks, picnic sites, lookouts, swimming holes, fishing and

camping spots and historic bridges

• Numerous opportunities for recreation including picnic sites, swimming holes, camping,

fishing, kayaking, rock-climbing and abseiling


activities.

The Moorabool River is identified as a priority waterway in the Coranagmite Waterway Strategy and

in Water for Victoria as a Flagship Waterway and large-scale restoriation project

Citizen science projects conducted in the Moorabool landscape zone:

Above: Yarrowee River, Magpie. Photo Corangamite CMA

44

• The Pesticide Detectives – 1 site

• The National Waterbug Blitz – 2 sites

Community Groups active in the Moorabool landscape zone that have contributed to data collection:

• Moorabool Catchment Group

• Lal Lal Catchment Group

• People for a Living Moorabool

• Friends of Brisbane Ranges

A total of eleven monitoring sites are assessed in the Moorabool landscape zone for this project

(Figure 22).

45

Figure 22. The location of sites represented as yellow dot with the site code in the Moorabool landscape zone. (Map sourced from CCMA CWS 2013)

46


Over the assessment period (2005 – 2020), the water quality in the Moorabool Landscape zone

changed over time. The millennium drought (1997 – 2010) and the introduction of environmental

flows to the Moorabool River resulted in these variations.

At the most upstream site CO_MOW080 on the West Branch of the Moorabool River electrical

conductivity was mostly under 1000 µS/cm post 2011 (Figure 23). Higher levels were recorded pre

2011 due to reduced river flow associated with the millennium drought. The pH was maintained at

relatively healthy levels. Dissolved oxygen levels were also mostly maintained at healthy levels, the

lower dissolved oxygen levels were recorded from 2008 – 2010, most likely due to low river flows

resulting from the millennium drought. From 2012 turbidity remained at low levels (10 NTU).

Reactive phosphate ranged from 0 (undetectable) to a very high 1.2 mg/L, high levels were recorded

between 2010 and 2013 (Figure 23), from 2014 on lower levels were recorded and are likely to be of

concern.

Site CO_MOE070 the most upstream site assessed on the East Branch of the Moorabool River

displayed greater variability in the water quality indicators. There is a distinct seasonal pattern with

increased electrical conductivity in late summer (Figure 24), possibly due to reduced or no river flow

and the potential ingression or saline groundwater. Electrical conductivity is commonly high at this

site. The pH was maintained at relatively healthy conditions. The dissolved oxygen ranged from a

very low 4% to 89% saturation, the very low levels were recorded from 2009 to 2010. As with the

electrical conductivity the dissolved oxygen follows a seasonal trend with low dissolved oxygen

levels in late summer most likely due to reduced or no river flow (Figure 24). The turbidity ranged

from 9 to 400 NTU, once again the high level (400 NTU) was recorded in 2010 likely due to the

return of flow to the river as this coincides with greatly reduced electrical conductivity. Following this

event turbidity levels were mostly low (< 15 NTU) with increases associated with decreased

electrical conductivity (ie increased river flow). Reactive phosphate ranged from 0.0 (undetectable)

to 0.14 mg/L as with other indicators the high value was recorded in 2010. A step change with

increased reactive phosphate occurs in 2017.

Figure 23. Site CO_MOW080 displaying the reactive phosphate and electrical conductivity from 2007 to 2018.

47

The next site downstream CO_MOO001 is at the confluence of the West and East branches of the

Moorabool River. The water quality indicators follow a similar pattern as the two upstream sites with

improvements occurring from 2011, post the millennium drought. Seasonal trends of low electrical

conductivity over summer are evident (Figure 25) and may be due to the implementation of

environmental flows to the Moorabool River. The pH ranged from 6.6 to 8.5 pH units, and was

maintained at healthy levels. The dissolved oxygen ranged from 16% to 89% saturation, post 2010

the lowest dissolved oxygen level was 50% saturation and maintained relatively healthy levels.

Turbidity levels post 2010 were mostly very low (<10 NTU). Reactive phosphate ranged from 0.00 –

0.06 mg/L. Similar to site CO_MOE070 on the East Branch of the Moorabool River a step change

with increased reactive phosphate occurs in 2017 (Figure 25).

At site CO_MOO004 a similar pattern post 2010 occurred as observed at the sites upstream.

Electrical conductivity was maintained at low levels post 2010 (Figure 26). The pH was maintained

Figure 24. Site CO_MOE070 displaying the dissolved oxygen and electrical conductivity from 2007 to 2020.

Figure 25. Site CO_MOO001 displaying the reactive phosphate and electrical conductivity from 2008 to 2020.

48

at healthy levels. The dissolved oxygen ranged from 49% to 115% saturation, post 2010 the lowest

dissolved oxygen level was 59% saturation and maintained near healthy levels (Figure 26). Post

2013 overall levels have lowered. Turbidity levels were mostly low (<10 NTU). Several high levels

were recorded in 2016 (80 NTU) and 2019 (90 NTU). Reactive phosphate ranged from 0.00 – 0.15

mg/L. Similar to site CO_MOE070 on the East Branch of the Moorabool River and site CO_MOO001

a step change with increased reactive phosphate occurs in 2017.

At site CO_MOO010 a similar pattern post 2010 occurred as observed at the sites upstream. A

seasonal trend of lower conductivity over late summer is evident (Figure 27). The pH was

maintained at healthy levels. The dissolved oxygen ranged from 18% to 98% saturation, post 2010

the lowest dissolved oxygen level was 18% saturation in March 2016. Turbidity post 2010 levels was

mostly low (<10 NTU). Several high levels were recorded in 2016 (180 NTU), 2017 (160 NTU) and

2019 (130 NTU) at times of increased river flow (Figure 27). Reactive phosphate ranged from 0.00

to 0.03 mg/L and was maintained at relatively low levels.

Figure 26. Site CO_MOO004 displaying the dissolved oxygen and electrical conductivity from 2007 to 2020.

Figure 27. Site CO_MOO010 displaying the turbidity and electrical conductivity from 2008 to 2020.

49

At site CO_MOO020 a similar pattern post 2010 occurred as observed at the sites upstream.

Electrical conductivity ranged from 440 to 3400 µS/cm, with lower levels post 2010. A seasonal trend

of lower conductivity over late summer early autumn is evident (Figure 28). The pH ranged from 7.0

to 8.6 pH units, maintaining relatively healthy levels. The dissolved oxygen ranged from 63% to

105% saturation, apparent is a decrease in dissolved oxygen following times of low electrical

conductivity (Figure 28), possibly due to increased organic matter entering the river during times of

environmental flows in late summer. Also apparent is a downward trend in levels over the last two

years. Post 2010 turbidity levels were mostly low (<10 NTU). Several high levels were recorded in

2016 (100 NTU), and 2019 (100 NTU). Reactive phosphate ranged from 0.00 – 0.08 mg/L and was

maintained at relatively low levels.

At site CO_MOO025 monitoring commenced in 2017, limited data has been collected. Electrical

conductivity ranged from 386 to 5970 µS/cm. Only one very high value was recorded in 2017 (5,970

µS/cm), outside of this the highest value was 1,358 µS/cm. The pH remained stable at 7.0 pH units,

maintaining healthy levels. No dissolved oxygen was measured at this site. Turbidity ranged from 8

to 24 NTU. Reactive phosphate ranged from 0.015 to 0.045 mg/L and was maintained at relatively

low levels.

At site CO_MOO045 monitoring also commenced in 2017 and has limited data. Electrical

conductivity ranged from 589 to 2310 µS/cm. A seasonal trend of higher conductivity over late

summer is evident. The pH ranged from 7.0 to 7.7, maintaining healthy levels. The dissolved oxygen

ranged from 18% to 86% saturation, also apparent is a decrease in dissolved oxygen in late summer

as conductivity rises (Figure 29). Turbidity ranged from 9 to 100 NTU, although mostly low (<10

NTU), higher values were recorded in late winter, at times of lower electrical conductivity suggesting

increased river flow. Reactive phosphate ranged from 0.00 to 0.08 mg/L and was maintained at

relatively low levels. High values (2 records) (0.14 mg/L) were recorded at the same time as the high

turbidity.


50

Site CO_MOO091 is the last site on the Moorabool River upstream of the confluence with the

Barwon River monitoring commenced in 2018. An increase in electrical conductivity occurs at this

site. A seasonal trend of higher conductivity over summer is evident (Figure 30). The pH ranged

from 7.5 to 8.0 pH units, maintaining healthy levels. The dissolved oxygen ranged from 41% to 89%

saturation), also apparent is a decrease in dissolved oxygen in late summer as with the two previous

sites CO_MOO025 and CO_MOO045. Turbidity ranged from 9 to 120 NTU, higher values were

recorded in late winter at times of lower electrical conductivity suggesting increased river flow

(Figure 30). Reactive phosphate ranged from 0.03 – 0.14 mg/L. As with the previous site high values

(2 records) (0.14 mg/L) were recorded around the same time as the high turbidity.


Figure 30. Site CO_MOO091 displaying the turbidity and electrical conductivity from 2017 to 2020.

51

Tributaries of the Moorabool River


Site CO_TEA030 is on Tea Tree Creek, a tributary of the Moorabool River downstream of site

CO_MOO004. Electrical conductivity ranged from 160 to 19,450 µS/cm. A seasonal trend of higher

conductivity over summer is evident. This site regularly has electrical conductivity above 5,000

µS/cm, indicating the ingression of saline ground water occurs (Figure 31). These high levels will

impact on the aquatic life in this waterway. The pH ranged from 6.2 to 9.1 pH units, there is a trend

of high values occurring in late summer likely due to algal growth (Figure 31). Over summer this

creek is reduced to pools or completely dries, enabling a build-up of organic matter in the river

channel, on rewetting this can result in the release of nutrients and consumption of oxygen by

microbial action. The dissolved oxygen ranged from 7% to 102% saturation. Low dissolved (<70%

saturation) is regularly recorded at this site. Turbidity ranged from 9 to 400 NTU, the high values

were recorded at times of lower electrical conductivity suggesting increased river flow. Reactive

phosphate ranged from 0.00 – 0.11 mg/L. There appears to be a gradual increase in reactive

phosphate from 2014 to 2017. The highest values were recorded toward the end of the millennium

drought pre 2011.

Site CO_SUT015 is on Sutherland Creek, a tributary of the Moorabool River, the tributary joins the

Moorabool River upstream of site CO_MOO045. Electrical conductivity ranged from 606 to 8,410

µS/cm. No seasonal trend is evident. The highest level occurred in 2018 (Figure 32). The pH ranged

from 6.8 to 8.7 pH units, there is a trend of high values occurring in late summer to early autumn.

The dissolved oxygen ranged from 38% to 105% saturation, the lowest value (38% saturation) was

recorded in 2013 at a time of high turbidity and electrical conductivity suggesting there to be low or

no river flow and the ingression of saline groundwater into isolated pools (Figure 32). Turbidity

ranged from 2 to 50 NTU, the high values were recorded at times of high electrical conductivity.

Reactive phosphate ranged from 0.00 – 0.045 mg/L. High values followed a similar trend to turbidity.

Figure 31. Site CO_TEA030 displaying the pH and electrical conductivity from 2008 to 2020.

52


Sites on the Moorabool River in the Moorabool landscape zone

The water quality in the Moorabool River met most of the SEPP (Waters) environmental water

quality objectives, indicating beneficial uses are potentially at risk (Table 22).

• All sites met the upper and lower objectives for pH with the exception site CO_MOO020

(8.10 pH units) and site CO_TEA030 (8.40 pH units) a tributary of the Moorabool River.

• All sites met the objective for turbidity with the exception of site CO_MOO091 (27 NTU) and

CO_TEA030 (21 NTU).

• All sites met the objective for reactive phosphate with the exception of site CO_MOW080

(0.110 mg/L) and site CO_MOO045 (0.080 mg/L).

• Less than half the sites met the objective for electrical conductivity, including sites

CO_MOE070 (2600 µS/cm), CO_MOO020 (2100 µS/cm), CO_MOO025 (2660 µS/cm),

CO_MOO091 (3065 µS/cm), CO_TEA030 (9200 µS/cm) and site CO_SUT015 (3800

µS/cm).

• All sites met the dissolved oxygen maximum objective (max. ≤ 130% saturation), whilst only

two sites met the lower dissolved oxygen objective (25% percentile ≥ 70% saturation). Sites

that did not met the objective include CO_MOE070 (42% saturation), CO_MOO001 (64%

saturation), CO_MOO004 (69% saturation), CO_MOO010 (64% saturation), CO_MOO045

(46% saturation), CO_MOO091 (65% saturation), CO_TEA030 (56% saturation) and site

CO_SUT015 (64% saturation).

As these results require the calculation of percentiles of the water quality indicators any sites with

pre 2011 data will be impacted by variable conditions associated with the Millennium drought. Post

2011 conditions were improved at many sites.

Figure 32. Site CO_SUT015 displaying the dissolved oxygen and electrical conductivity from 2011 to 2020.

53

Table 22. Water quality assessment against State Environment Protection Policy (Waters) for sites in the

Moorabool Lanscape Zone. (Blue and green indicate objective is met, benificial uses are protected, orange

and red indicate objective is not met, benificial uses may be at risk).




Turbidity (NTU)

Reactive Phosphate (mg/L)


CO_MOW080 81 76 120 1150 7.50 7.90 12 0.110

CO_MOE070 144 42 88 2600 7.30 7.60 10 0.030

CO_MOO001 136 64 89 1038 7.30 7.80 10 0.030

CO_MOO004 107 69 115 1240 7.40 7.90 10 0.030

CO_MOO010 132 64 98 1300 7.50 8.00 9 0.015

CO_MOO020 154 81 105 2100 7.60 8.10 10 0.029

CO_MOO025 15 NA NA 2660 7.00 7.50 9 0.030

CO_MOO045 14 46 86 1847 7.50 7.70 14 0.080

CO_MOO091 13 65 89 3065 7.50 8.00 27 0.055

CO_TEA030 122 56 102.07 9200 7.65 8.40 21 0.030

CO_SUT015 19 64 105 3800 7.05 7.70 10 0.030

Aquatic macroinvertebrate assessment in the Moorabool landscape zone

Aquatic macroinvertebrate monitoring was undertaken at six sites in the Moorabool Landscape Zone

over the assessment period (2005 to 2020) (Table 23). The weighted SIGNALT scores indicate all

sites on the Moorabool River to be mildly impacted with the exception of site CO_MOO004 being

heavily impacted (2011 to 2013 only). On Sutherland Creek tributary thirteen surveys have been

performed from 2012 to 2019, the score indicates the site to be mildly to heavily impacted.

Table 23. Results of macroinvertebrate surveys in the Moorabool Landscape zone from 2005 to 2020.


CO_MOO001 7 October 2015 ALT 4.8

CO_MOO004 4 April 2011 Order 3.1



CO_MOO020 10 November 2010 Order 4.7

27 September 2012 ALT 4.2

11 April 2016 ALT 3.9

CO_MOO025 17 December 2018 NWB ALT 3.8

CO_MOO045 23 November 2017 ALT 4.2

CO_SUT015 13 May 2012 ALT 4.0


54


CO_SUT015 10 February 2013 ALT 4.3

11 May 2013 ALT 2.3

9 November 2014 Order 4.4

15 March 2015 ALT 4.2

9 August 2015 ALT 4.2

14 February 2016 ALT 2.4


15 March 2017 ALT 4.2

12 November 2017 ALT 3.0

15 April 2018 ALT 2.9


Summary of the Moorabool landscape zone

The water quality in the Moorabool River has changed over time. Pre 2011 high salinity was

common due to water extraction and reduced flows associated with the Millennium drought. Post

2011 and the introduction of environmental flows particularly over summer to autumn helped lower

salinity and improve dissolved oxygen levels. Salinity levels were higher in the East Branch in

comparison to the West Branch whilst reactive phosphate levels were higher in the West Branch.

At the confluence of the East and West Branch the water quality is maintained at relatively healthy

levels, increases in salinity occur downstream, likely influenced by seasonal flow from the tributaries

such as Teatree and Sutherland Creeks, there is evidence during low flow saline groundwater enters

these streams, whilst the sites on these waterways have good riparian vegetation and aquatic

habitat, the macroinvertebrate community structure indicate the water quality to be degraded.

Near to the confluence with the Barwon River the water quality has declined with increased salinity

possibly associated with discharges from the Batesford quarry. Throughout the catchment the

habitat quality is degraded. A lack of riparian vegetation, unrestricted stock access and poor aquatic

habitat are evident.

The implementation of environmental flows have improved the overall water quality in the Moorabool

River, particularly the East Branch, whilst over time it appear dissolved oxygen levels have declined

marginally.

Above: Monitoring site CO_MOO010 displaying good habitat quality

55

CCMA Actions in the Moorabool landscape zone

The Corangamite Catchment Management Authority has set management activities in the

Moorabool landscape zone to address water quality threats in the area (Table 24), for further


Table 24. CCMA management activities to address water quality threats in the Moorabool landscape zone.


Establish terrestrial pest animal control – rabbit control Moorabool River Moorabool River West Branch Sutherland Creek West Branch


Moorabool River Moorabool River West Branch Sutherland Creek West Branch Moorabool River East Branch Spring Creek Lal Lal Creek






Moorabool River

Deliver current environmental water entitlement and develop long-term planning for environmental watering of the Moorabool River (EWMP)

Moorabool River Moorabool River West Branch

Investigate impacts to environmental flows throughout the broader Moorabool catchment basin to secure and better manage environmental water where required.

Moorabool River Moorabool River West Branch Moorabool River East Branch


Moorabool River Moorabool River West Branch Moorabool River East Branch


Moorabool River

Undertake woody weed control Moorabool River Moorabool River West Branch Moorabool River East Branch Spring Creek Lal Lal Creek

Develop land and gully stabilisation plan for the Eclipse Creek catchment

Moorabool River

Investigate and manage urban stormwater/water quality impacts in line with whole of water cycle management principles

Moorabool River

Investigate stream instabilities Sutherland Creek West Branch Spring Creek


Lal Lal Reservoir, Wilsons Reservoir, Moorabool Reservoir, Bostock Reservoir, Korweinguboora Reservoir

Maintain the discharge into the Moorabool River from Batesford Quarry as a beneficial environmental use – as per the Central Region Sustainable Water Strategy

Moorabool River



56

The Bellarine landscape zone

The Bellarine landscape zone encompasses the Bellarine Peninsula east of Geelong. It also

includes a large portion of the southern suburbs of Geelong and the lower Barwon River. Port Phillip

and Corio bays provide the northern extremities while the southern coast faces onto the open waters

of Bass Strait.

The major river in this landscape zone is the lower Barwon River, which is the main source of fresh

water to the lower Barwon wetlands and estuary. Both the wetlands and estuary are significant

features of the landscape and encompass a number of environmental, cultural, social and economic

values. The estuarine reach of the Barwon River incorporates a system of wetlands and lakes

including Lake Connewarre, Reedy Lake, Hospital Swamp and Murtnaghurt Lagoon. These

wetlands form part of the Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar Site.

They consist of a diverse range of aquatic vegetation communities, providing important feeding and

breeding habitat for native fish and a number of wetland-dependent bird species, including the

nationally vulnerable Australian painted snipe, and critically endangered orange-bellied parrot. In the

region, agriculture accounts for 64% of land use and urban accounts for 20%.

The region also includes the Barwon River Parklands and the urban reaches of the Barwon River

through Geelong, which is highly valued for its environmental amenity and recreation.

During the development of the Corangamite Waterway Strategy 2014 – 2022 the Bellarine


• support for biodiversity including many species of fish and birds of international significance

• spectacular scenery with intrinsic environmental value

• parks, picnic sites, lookouts, swimming areas, fishing and camping spots and walking tracks,

such as the Bellarine Rail Trail

• a State Game Reserve, which supports a range of values including game hunting

• local waterways including Yarram and Frederick Mason Creeks, Mc Leods Waterholes and

Lake Lorne, that support significant plants, animals and vegetation communities, as well as

social and cultural values.

• Barwon River Parklands and the urban reaches of the Barwon River through Geelong are

highly valued for its environmental amenity and recreation, including rowing, water skiing,

boating, walking tracks, kayaking and sightseeing.

Citizen science projects conducted in the Bellarine landscape zone:

• Australian Platypus Monitoring Network -4 sites

• The Pesticide Detectives - 3 sites

• The National Waterbug Blitz – 1 site

• The Barwon Estuary Monitoring Pilot Project

• The Victorian Index of Estuary Condition (2018 – 2019)

Community Groups active in the Bellarine landscape zone

• Bellarine Catchment Network

• Bellarine Landcare Group

• The Geelong Field Naturalists Club

• Barwon Heads Association

57

A total of six Waterwatch monitoring sites and five EstuaryWatch sites are assessed in the Bellarine

landscape zone for this project (Figure 33).


Over the assessment period (2005 – 2020), the water quality in the Bellarine Landscape zone varied

across the landscape. Site CO_BAR132 at Balyang, Canoe Club platforms in Geelong displayed to

best water quality in the freshwater reaches.

Just downstream of the confluence of the Moorabool and Barwon Rivers at site CO_BAR110 the

water quality declines due to inputs from the Moorabool River. A season trend is evident with higher

electrical conductivity over summer (Figure 34). An increase in summer electrical conductivity

occurred from 2013 to present, likely associated with discharge from the Batesford quarry to the

Moorabool River. Prior to 2013 electrical conductivity did not exceed 3000 µS/cm. The pH ranged

from 6.4 to 9.1 pH units, one low values (< 6.5 pH units) was recorded in 2019 (6.4 pH units) and

three high value (> 8.5 pH units) were recorded in 2007 (9.1 and 8.9 pH units) and 2012 (9.3 pH

Figure 33. The location of sites represented as yellow dot with the site code in the Bellarine landscape zone. (Map sourced from CCMA CWS 2013)

58

units). Dissolved oxygen levels ranged from 34% to 149%, greater variability is evident prior to 2012

(Figure 34). The range from 2012 to present is 51% to 109% saturation. High dissolved oxygen

levels were recorded on three occasions in 2005 (124%), 2007 (149%) and 2010 (125%) indicating

potential excessive macrophyte or algal growth. The turbidity ranged from 1 to 115 NTU, high values

were recorded at times of low electrical conductivity suggesting increased river flows generally

results in increased turbidity. Also evident is an increase in flow related turbidity values from 2012,

likely due to increased river flow following the millennium drought. Reactive phosphate ranged from

0 (undetectable) to a 0.4 mg/L, indicating this site experiences high levels of reactive phosphate at

times which can result in excessive macrophyte and algal growth.

As the river flows through the Geelong urban landscape to site CO_BAR132 irregular monitoring

commenced in 2013, regular monthly monitoring commenced in mid-2018. The water quality

followed similar trends to the previous site and is indicative of the water quality conditions mid- 2018

to 2020. A season trend is evident with higher electrical conductivity over summer (Figure 35).


Figure 35. Site CO_BAR132 displaying the reactive phosphate and electrical conductivity from 2013 to 2020.

59

The pH and dissolved oxygen was mostly maintained in the healthy range. High turbidity was

recorded at times of low electrical conductivity indicating increased river flows. Reactive phosphate

ranged from 0 (undetectable) to a 0.18 mg/L, indicating this site experiences high levels of reactive

phosphate at times which can result in excessive macrophyte and algal growth (Figure 35).

On the bank of the Barwon River at the Pakington St wetland site CO_PAK001, regular monitoring

commenced in 2010, several seasonal trends are evident. Electrical conductivity remained low

(<1000 µS/cm), a seasonal trend is evident with higher electrical conductivity over summer. The pH

was mostly maintained in the healthy range. Dissolved oxygen levels ranged from 0% to 140%

saturation, low levels (< 50%) were regularly recorded during the summer to autumn seasons. The

turbidity ranged from 0 to 400 NTU, high values were recorded regularly and are likely due

stormwater inputs. Reactive phosphate ranged from 0.015 to a high 1.6 mg/L, increases in reactive

phosphate occurred during times of increased turbidity. This site experiences high levels of reactive

phosphate at times which can result in excessive macrophyte and algal growth.

Just downstream from the Pakington St wetland is the Jerringot Wetlands. Regular monitoring was

undertaken between 2011 and 2015. The water quality observed at site CO_JER010 displayed

several seasonal trends. As with the previous sites, a seasonal trend is evident with higher electrical

conductivity over summer (Figure 36). The pH was mostly in the healthy range. Dissolved oxygen

levels ranged from 28% to 120% saturation, low levels (< 50%) were regularly recorded during the

summer to autumn seasons. The turbidity ranged from 9 to 130, high values were recorded during

summer and are likely due to increase algal growth and decay in the water column (Figure 36).

Reactive phosphate ranged from 0 (undetectable) to a high 1.4 mg/L, indicating this site experiences

high levels of reactive phosphate at times which can result in excessive macrophyte and algal

growth.

At the most downstream freshwater site CO_BAR161 monitoring from 2005 to 2015 was limited,

from 2015 monthly monitoring commenced. Electrical conductivity regularly exceeded 3000 µS/cm,

a season trend is evident with higher electrical conductivity over summer (Figure 37). The pH was

mostly in the healthy range. Dissolved oxygen levels ranged from 45% to 135% saturation, low

levels (< 50% saturation) were regularly recorded during summer from 2016 to present (Figure 37).

The turbidity ranged from 5 to 65 NTU, high values were recorded at times of low electrical

conductivity suggesting increased river flows as with the previous site. Reactive phosphate ranged

Figure 36. Site CO_JER010 displaying the turbidity and electrical conductivity from 2011 to 2020.

60

from 0 (undetectable) to a 0.35 mg/L, indicating this site experiences high levels of reactive

phosphate at times which can result in excessive macrophyte and algal growth.

Downstream from site CO_BAR161 is the confluence of Waurn Ponds Creek. Monitoring was

regularly undertaken from 2005 to 2010. Site CO_WAU012 on Waurn Ponds Creek did not display

the distinct seasonal trends observed at other sites, a slight seasonal trend is evident with higher

electrical conductivity over summer (Figure 38). Electrical conductivity was consistently high, at

times of low or no flow ingression of saline groundwater may occur at this site.

The pH was maintained at healthy levels. Dissolved oxygen levels ranged from 25% to 140%

saturation), low levels (< 50% saturation) were recorded during the summer season (Figure 38). The

turbidity was mostly low, the turbidity levels increased as electrical conductivity decreased, and are

likely due to stormwater inputs. This site experiences high levels of reactive phosphate at times


Figure 38. Site CO_WAU012 displaying the dissolved oxygen and electrical conductivity from 2005 to 2018.

61

which can result in excessive macrophyte and algal growth. Monitoring of reactive phosphate was

only undertaken in 2009.

The next site is the start of the Barwon River estuary, at the lower breakwater (site B6). Monitoring

commenced in 2008 however, limited monitoring has been conducted. The water quality over the

period of assessment displayed several patterns. Depth profiling displays times when the water is

stratified on a salinity gradient. Surface electrical conductivity ranged from 0.41 to 53.7 (mS/cm) and

bottom electrical conductivity ranged from 1.031 to 58.9 (mS/cm). On the majority of occasions the

electrical conductivity was higher in the bottom waters than the top (Figure 39). At times the

electrical conductivity is similar to that observed in sea water (55 mS/cm) indicating low river flow.

Following times of high rainfall in the catchment this site displays electrical conductivities similar to

that observed in the freshwater reaches upstream. The pH was mostly at healthy levels. Dissolved

oxygen levels ranged from 60% to 143% saturation in the top waters and 7 to 114% saturation in the

bottom. On many occasions lower dissolved oxygen levels were observed in the bottom waters, this

occurred at times when salinity stratification is evident, very low levels (14% and 12 % saturation)

were observed in the bottom waters on several occasions (Figure 39). These low levels may be

harmful to salt water dependant fish species. High dissolved oxygen levels (143% saturation)

observed on February 2013 is likely due to increased algal growth in the surface waters.

The turbidity ranged from 10 to 60 NTU in the top waters and 6 to 100 NTU in the bottom. From

2013 to present the turbidity was lower in the bottom waters, however prior to 2013 the bottom

waters were higher. This may be due to the meeting of the freshwater river with the saltwater of the

estuary at the breakwater and the turbulence caused by the constructed breakwater.

Just downstream from the lower breakwater the Barwon River opens into Lake Connewarre. On the

banks of Lake Connewarre at Taits Point is site B5. Monitoring commenced in late 2007. Over the

assessment period the water quality observed at site B5 displayed several seasonal trends. As this

site is very shallow differences between the surface and bottom waters is minimal. Surface electrical

conductivity ranged from 0.064 to 61.7 mS/cm and bottom electrical conductivity ranged from 0.069

to 61.5 mS/cm. A distinct seasonal pattern is evident, with winter to spring electrical conductivity

representing that of freshwater due to increased river flow, as river flow declines the electrical

conductivity increases due to the influence of tidal seawater making its way up the estuary into Lake

Connewarre. At times when river flow is greatly reduced, generally over summer and autumn the

Figure 39. Site B6 displaying the dissolved oxygen and electrical conductivity from 2008 to 2020.

62

electrical conductivity is greater (hypersaline) than that observed in seawater, this occurred in 2013,

2014 and 2016. The pH ranged from 6.7 to 9.5 pH units in the top waters and 7 to 9.6 pH units in the

bottom (Figure 40). High pH levels (> 9 pH units) occurred over summer in 2009, 2012, 2017 and

2018 most likely due to increased algal growth. Dissolved oxygen levels ranged from 8.5% to

193.6% saturation in the top waters and 7.9% to 300% saturation in the bottom. High dissolved

oxygen levels (> 130% saturation) were observed in 2010, 2012, 2017, 2018, and 2019 in both the

top and bottom waters (Figure 40), on these occasions the bottom waters were higher than the top

indicating likely mass algal growth on the bottom substrate. Low dissolved oxygen levels were

observed in 2010, 2011, 2016, 2017 and 2018, on several occasions low levels were only in the

bottom waters. The turbidity ranged from 0 - 200 NTU in the top waters and 1.5 - 400 NTU in the

bottom. From 2008 to present the turbidity was lower in the top waters. The shallow depth at this site

may influence turbidity levels with wind generated wave action disturbing sediments.

Site B4 is just downstream from Lake Connewarre in the main river channel. Monitoring commenced

in 2010, access difficulties resulted in reduced monitoring. Over the assessment period the water

quality at site B4 displayed several seasonal trends. A distinct seasonal pattern is evident, with

winter to spring electrical conductivity representing close to that of freshwater due to increased river

flow, as river flow declines the electrical conductivity increases due to the influence of the tidal salt

wedge making its way up the estuary. Over summer when river flow is greatly reduced, the electrical

conductivity is greater (hypersaline) than that observed in seawater, this occurred in 2013 and 2016

(Figure 41). On the majority of occasions the electrical conductivity was higher in the bottom waters

than the top. The pH ranged from 5.8 to 8.6 pH units in the top waters and 6.5 to 8.8 pH units in the

bottom, maintaining relatively healthy levels. Low pH levels (< 6 pH units) occurred over summer in

2013. Dissolved oxygen levels ranged from 49% to 145% saturation in the top waters and 44% to

143% saturation in the bottom (Figure 41). On one occasion in February 2012 lower dissolved

oxygen levels (< 50% saturation) were observed in both top and bottom waters. High dissolved

oxygen levels (> 130% saturation) were observed in January 2012 and April 2017 is likely due to

increased algal growth in the surface waters. The turbidity ranged from 4.9 to 150 NTU in the top

waters and 4.7 to 150 NTU in the bottom. The bottom turbidity was lower on many occasions

possible due to stratification from salt wedge development. The highest turbidity (150 NTU) was

Figure 40. Site B5 displaying the pH and dissolved oxygen from 2009 to 2020.

63

recorded on three occasions in 2012. Turbidity may also increase as water drains out of Lake

Connewarre as the tide recedes particularly during summer if an algal bloom is present.

Further down the estuary at the Sheepwash boat ramp in Barwon Heads is site B2. Over the

assessment period the water quality observed at site B2 displayed several seasonal trends. Surface

electrical conductivity ranged from 0.921 to 69.2 mS/cm and bottom electrical conductivity ranged

from 0.934 to 68.6 mS/cm. A distinct seasonal pattern is evident, with winter to autumn electrical

conductivity representing close to that of freshwater due to increased river flow, this is short lived, as

river flow declines the electrical conductivity increases due to the influence of the tidal salt wedge

making its way up the estuary (Figure 42). On two occasions over summer when river flow is greatly

reduced, the electrical conductivity was greater than that observed in seawater, this occurred in

2012 and 2019 likely due to the run out tide draining water from Lake Connewarre, also over

summer and autumn the water represents that of seawater, tidal influences dominate this site. The

pH ranged from 6.9 to 8.5 pH units in the top waters and 7.1 to 8.7 pH units in the bottom,

maintaining relatively healthy levels. Dissolved oxygen levels ranged from 44.7% to 119.6 %

saturation in the top waters and 45.6% to 119.6% saturation in the bottom. On one occasion in


Figure 42. Site B2 displaying the turbidity and electrical conductivity from 2008 to 2020.

64

March 2012 lower dissolved oxygen levels (< 50% saturation) were observed in both top and bottom

waters this occurred at the time the electrical conductivity was above that observed in seawater

indicating the low dissolved oxygen is likely from waters draining out of Lake Connewarre and

fringing mangrove swamps as the tide recedes. The remainder of the time dissolved oxygen levels

were maintained in the healthy range. The turbidity ranged from 0 to 150 NTU in both the top and

bottom waters. The highest turbidity (150 NTU) was recorded on three occasions over the winter -

spring seasons in 2012, 2016 and 2018 at a time the estuary was dominated by freshwater from

high river flows.

Near the mouth of the estuary to the sea is site B1. Regular monitoring commenced in 2010. Over

the assessment period the water quality at site B1 displayed several seasonal trends. Surface

electrical conductivity ranged from 1.08 to 56.8 (mS/cm) (Figure 43), and bottom electrical

conductivity ranged from 1.07 to 57.7 (mS/cm). A distinct seasonal pattern is evident. The tidal

influences dominate this site resulting in the electrical conductivity representing that of seawater

most of the time (Figure 43). During high river flows the electrical conductivity is reduced. On

September 2017 the water represented that of freshwater. There appears to be complete mixing of

water at this site with top and bottom waters mostly the same due to significant tidal currents.

The pH ranged from 6.5 to 8.4 pH units in the top waters and 7.1 to 8.5 pH units in the bottom,

maintaining healthy levels. Dissolved oxygen levels ranged from 65% to 124% saturation in the top

waters and 54% to 123% saturation in the bottom (Figure 43), also maintaining healthy levels. The

turbidity ranged from 0 to 150 NTU in the top waters and 0 to 150 NTU in the bottom. The highest

turbidity (150 NTU) was recorded on two occasions over the spring seasons in 2007 and 2016.


The Barwon River estuary in the Bellarine landscape zone

The water quality in the freshwater reaches of the Barwon River met some of the SEPP (Waters)

environmental water quality objectives, indicating beneficial uses are potentially at risk (Table 25).

• All sites met the turbidity objective (<25 NTU) and both pH objectives with the exception of

site CO_BAR110 marginally exceeding the upper objective (8.0 pH units).


65

• All sites met the lower dissolved oxygen objective, however sites CO_BAR110 and

CO_BAR161 did not met the upper objective (< 130% saturation).

• No site met the electrical conductivity objective.

• At the wetland site CO_PAK001 the water quality met the SEPP (Waters) objectives for

electrical conductivity and pH only. The water quality exceeded the objective for turbidity and

total phosphorus and did not meet both the lower and maximum objective for dissolved

oxygen indicating the beneficial uses of the wetland may be at risk.

• At the wetland site CO_JER010 the water quality met the SEPP (Waters) objectives for

electrical conductivity, pH, turbidity and the maximum objective for dissolved oxygen. The

water quality did not meet the lower dissolved oxygen objective and exceeded the total

phosphorous objective indicating the beneficial uses of the wetland may be at risk

• At the Waurn Ponds Creek site CO_WAU012 the water quality met the SEPP (Waters)

objectives for turbidity and pH only. The water quality exceeded the objective for electrical

conductivity, total phosphorus and did not meet both the lower and maximum objective for

dissolved oxygen indicating the beneficial uses of the creek may be at risk.

Table 25. Freshwater sites of the lower Barwon River, water quality indicators and comparison with SEPP

(Waters) objectives. (Blue and green indicate objective is met, beneficial uses are protected, orange and red

indicate objective is not met, beneficial uses may be at risk).




Turbidity (NTU)

Reactive Phosphate

(mg/L)

Site Code 25th% Max 75th% 25th%

75th%

75th% 75th%

CO_BAR110 77 149 2580 7.80 8.20 20 0.076

CO_BAR132 78 99 2825 6.95 7.50 17 0.048

CO_PAK001 17 140 190 7.00 7.00 30 0.400

CO_JER010 55 120 1755 7.00 7.50 22 0.140

CO_BAR161 70 135 2795 7.35 7.90 20 0.080

CO_WAU012 65 140 4200 7.50 7.80 16 0.085

The water quality in the estuarine reaches of the Barwon River met some of the SEPP (Waters)

environmental water quality objectives, indicating beneficial uses are potentially at risk (Table 26).

• At site B6 the water quality met the SEPP (Waters) objectives for bottom dissolved oxygen,

however exceed both dissolved oxygen objectives for top waters, the levels were just below

the lower dissolved oxygen objective (25th percentile 80% saturation). The upper maximum

exceeded the objective (max. 130% saturation). Both the top and bottom waters met the

lower pH objective but exceeded the upper pH objective. Both the top and bottom waters

exceeded the turbidity objective. Indicating beneficial uses may be at risk.

• At site B5 the water quality met the SEPP (Waters) lower dissolved oxygen objectives for top

and bottom waters, however exceed both dissolved oxygen maximum objectives (max.

130% saturation). Both the top and bottom waters met the lower pH objective but exceeded

the upper pH objective. Both the top and bottom waters exceeded the turbidity objective.

Indicating beneficial uses may be at risk.

• At site B4 the water quality met the SEPP (Waters) objectives for top and bottom dissolved

oxygen, however exceed both dissolved oxygen maximum objectives (max. 130%

saturation). Both the top and bottom waters met the pH objectives. Both the top and bottom

waters exceeded the turbidity objective. The beneficial uses are mostly protected at this site.

66

• At site B2 the water quality met the SEPP (Waters) objectives for dissolved oxygen and pH.

Both the top and bottom waters only marginally exceeded the turbidity objective. The

beneficial uses are protected at this site.

• At site B1 the water quality met all SEPP (Waters) objectives indicating the beneficial uses

are protected at this site.

Table 26. Estuarine sites of the lower Barwon River, water quality indicators and comparison with SEPP

(Waters) objectives. (Blue and green indicate objective is met, beneficial uses are protected, orange and red

indicate objective is not met, beneficial uses may be at risk).

Top - Dissolved

Oxygen (% Saturation)

Bottom - Dissolved

Oxygen (% Saturation)

Top - pH (pH units)

Bottom - pH (pH units)

Top - Turbidity

(NTU)

Bottom - Turbidity

(NTU)

Site 25th%

Max 25th% Max 25th% 75th% 25th% 75th% 75th% 75th%

B6 75.2 142.7 46.5 113.8 7.55 8.15 7.8 8.15 27 30

B5 86.5 193.6 84.95 300 7.8 8.3 7.8 8.4 40 60

B4 86.3 144.5 80.8 142.5 7 8 7.1 8 40 42.5

B2 89.8 119.6 89.3 119.6 7.8 8 7.8 8 13 12.25

B1 92.35 123.6 92.15 123.3 7.6 7.9 7.7 7.9 10 NA

Aquatic macroinvertebrate assessment in the Bellarine landscape zone

Aquatic macroinvertebrate monitoring was undertaken at five sites in the Bellarine Landscape Zone

over the assessment period. The weighted SIGNALT scores indicate all sites on the Barwon River to

be mildly to moderately impacted (Table 27), as these sites are in managed parklands the lack of

riparian vegetation and aquatic habitat at these sites is likely to reduce the diversity of

macroinvertebrates.

At the wetland site CO_PAK001 the score indicates the wetland is moderately impacted.

At the Waurn Ponds Creek tributary site CO_WAU012 two surveys were performed, the scores

indicate the creek to be mildly impacted.

Table 27. Results of macroinvertebrate surveys in the Bellarine Landscape zone from 2005 to 2020.


CO_BAR110 23 October 2017 Order 3.4


CO_BAR132 17 October 2011 Order 4.0

21 March 2013 ALT 3.2

30 April 2019 NWBB ALT 4.1


CO_BAR161 12 September 2012 Order 3.7


CO_PAK001 15 June 2012 Order 3.3

CO_WAU012 12 December 2007 Order 3.8

3 July 2015 ALT 3.6

67

Summary of the Bellarine landscape zone

As the Barwon River makes its way into Geelong after the confluence with the Moorabool River the

water quality is marginally degraded, increases in electrical conductivity over summer to autumn

post 2012 are evident. This increase is likely due to the environmental watering of the Moorabool

River, dissolved oxygen levels are also marginally lowered. High dissolved oxygen levels over

summer indicate potential algal growth, in the past this section of the Barwon River through Geelong

often experienced algal blooms over summer.

The Jerringot and Pakington St wetlands on the banks of the Barwon River receive urban

stormwater runoff. High phosphorus levels are common and may encourage macrophyte and algal

growth which potentially creates oxygen troughs over the summer to autumn seasons and raises pH

levels and ammonia toxicity. Macroinvertebrates indicate the water quality to be moderately

impacted.

The Waurn Ponds Creek a tributary of the Barwon River also displays poor water quality and at

times of low flows has the potential for saline groundwater intrusion, the creek also has high

phosphorus and turbidity levels. At the site there is a good cover of riparian vegetation however

there is potential for further bank erosion in this incised stream and the instream habitat for aquatic

organisms is degraded. Macroinvertebrates indicate the creek is mildly impacted.

As the Barwon River enters the estuary at the lower breakwater the water quality is relatively

healthy. During winter flooding flows in the catchment completely flush the estuary of saltwater and

becomes freshwater dominated, high turbidity occurs at this time however is only short lived and the

tidal salt wedge pushes back up the estuary. Occasionally over summer as river flow declines and

saltwater dominates. The effect of evaporation increases the salinity above that of seawater

(hypersaline) in the upper reaches of the estuary in Lake Connewarre. Also over summer there can

be an increase in algal growth in the surface waters and on the bottom substrate particularly as the

river flows into the shallow Lake Connewarre this effect is increased, at times the bottom waters

become super saturated with dissolved oxygen likely due to benthic algal mats photosynthesising.

As the river exits Lake Connewarre there is evidence of salt wedge development with salinity

stratification at times. Water quality is generally good, though potential algal growth may increase

dissolved oxygen levels over summer and autumn. Turbidity levels are likely influenced by tidal

movement out of Lake Connewarre particularly over summer.

As the river nears the estuary mouth to Bass Strait the water quality is very good. During seasonal

high river flows the water represents that of freshwater for a brief period, most of the time the water

representing that of seawater due to the strong tidal influence.

68

CCMA Actions in the Bellarine landscape zone

The Corangamite Catchment Management Authority has set management activities in the Bellarine

landscape zone to address water quality threats in the area (Table 28), for further information see

CCMA Corangamite Waterways Strategy 2014 - 2022.

Table 28. CCMA management activities to address water quality threats in the Bellarine landscape zone.


Establish terrestrial pest animal control – fox control (as part of a large scale coordinated program)

Barwon River

Hospital Swamp

Reedy Lake

Lake Connewarre

Lake Murtnaghurt


Barwon River

Waurn Ponds Creek

Install riparian/wetland fencing Barwon River

Waurn Ponds Creek

Hospital Swamp

Lake Murtnaghurt


Barwon River

Waurn Ponds Creek

Hospital Swamp

Lake Murtnaghurt


Reedy Lake

Ensure acid sulfate soils are considered in land use planning, works on waterways and water management decisions

Hospital Swamp

Reedy Lake

Lake Connewarre

Undertake non-woody weed control – spartina Lake Connewarre

Salt Lagoon

Barwon River

Deliver water to wetlands as per current entitlement (in consultation with the community and informed by the best available information) and develop long-term planning for environmental watering of the lower Barwon wetlands (EWMP)

Barwon River

Reedy Lake

Hospital Swamp

Investigate freshwater flows from adjoining land use Lake Murtnaghurt

Establish estuarine vegetation management plan Barwon River


Barwon River

Investigate and manage tidal barrage structural integrity Barwon River

Implement the Barwon River Parklands Strategy for management of the lower Barwon River corridor

Barwon River

Adopt ‘whole of water cycle management’ principles for new and existing developments

Barwon River

Fill knowledge gaps relating to impacts of water management at Reedy Lake and Hospital Swamp

Reedy Lake

Hospital Swamp

Investigate and manage urban stormwater/water quality impacts

Barwon River

Hospital Swamp

Reedy Lake

Lake Connewarre

Maintain EstuaryWatch groups collecting baseline data on estuary condition

Barwon River

69




Above: The Barwon river barrage where Index of Estuary Condition (IEC) monitoring has taken place with EstuaryWatch monitors. Photo Corangamite CMA

70

Summary of waterway condition

The Barwon River source to sea

The water quality across the Barwon River catchment over the past fifteen years has varied between

years and regions within the catchment. Error! Reference source not found. displays the

assessment with SEPP (Waters) environmental quality objectives, revealing the ratings on individual

indicators from sites within the catchment of the Barwon River.

As the Barwon River flows from the foothills of the upper catchment healthy water quality is evident,

having low salinity, turbidity and nutrients such as phosphorus (within SEPP (Waters) objectives).

Further down the catchment in the rural farmlands of the plains influences from the small tributary

streams are evident. These small streams have intermittent river flows and are greatly influenced by

seasonal rainfall at times being reduced to isolated pools or drying up completely. On rewetting after

a dry period this can lead to the lowering of pH due to the flushing of acid sulphide soils in the area,

this is particularly evident in Boundary Creek (exceeding SEPP (Waters) objectives), and lowering of

dissolved oxygen due to increased organic matter entering the streams as occurs in Pennyroyal

Creek (exceeding SEPP (Waters) objectives). In Deans Marsh Creek, a tributary of Pennyroyal

Creek and Mathews Creek sediment movement is also evident with increased turbidity levels

(exceeding SEPP (Waters) objectives).

Rainfall in these catchments transport sediments into the river, particularly from the small intermittent

streams that flow from the Otway Ranges such as Pennyroyal and Mathews creeks. Increases in

salinity also occur in these streams. Salinity levels were mostly low (within SEPP (Waters)

objectives) in this area except for the lower Pennyroyal Creek, at times of no river flow ingression of

saline ground water into pools may occur. Unrestricted stock access and lack of native riparian

vegetation along these streams impact these waterways. The influence of these tributaries on the

Barwon River is evident at several sites within close proximity downstream of their confluences. High

dissolved oxygen levels (exceeding SEPP (Waters) objectives) over summer to autumn at most sites

indicate potential excessive algal growth within the water column.

As the Barwon River flows from the township of Winchelsea and makes its way to Geelong it is

joined by the Leigh River at Inverleigh. Lake Wendouree and the northern wetland In Ballarat in the

head waters of the Yarrowee - Leigh River receives stormwater runoff from the regional town of

Ballarat. On most occasions the water quality was reasonably healthy displaying low salinity,

turbidity and phosphorus (the northern wetland exceeded SEPP (Waters) Total Phosphorus

objective), oxygen levels within the lake often varied between sites and sampling events though was

mostly healthy. At some sites variable oxygen levels were observed likely associated with aquatic

vegetation. Oxygen levels in waterways with an abundance of aquatic vegetation often display

diurnal fluctuations resulting from photosynthesis. At the times of monitoring high pH levels (> 9 pH

units) were observed at several sites.

In the Yarrowee – Leigh River sites are in the upper catchment, one upstream of Ballarat and one

downstream. The water quality of the upstream site was mostly healthy, though at times displayed

low dissolved oxygen and high turbidity. The water quality of the downstream site was also mostly

healthy however phosphorus levels were high. Williamsons Creek, at tributary of the Yarrowee –

Leigh River displayed relatively poor water quality. This intermittent stream exceeded most of the

SEPP (Waters) water quality objectives. High electrical conductivity levels at times indicate the

ingression of saline groundwater at times of low or no flow. High phosphorus levels also occur at this

site and are likely linked to farming practices in the area and imported to waterways attached to soil

71

particles, when this makes its way into the waterways it has the potential to increase the growth of

aquatic plants and even stimulate algal blooms.

The Leigh River provides additional flow to the Barwon River, however, some decline in some water

quality indicators are evident. Increases in phosphorus (exceeding SEPP (Waters) objective) occur

in a downstream direction and can be partially attributed to inflow from the Leigh River. The Bruce

Creek tributary of the Barwon River also highlights an area of saline ground water intrusion

particularly during times of low river flows exceeding the SEPP (Waters) objective and is also a

possible source of sediment as indicated by high turbidity levels (exceeding SEPP (Waters)

objective). All Barwon River sites exceeded SEPP (Waters) dissolved oxygen objectives. As the

Barwon River enters the city of Geelong the water quality is reasonably healthy for a lowland river

except for phosphorus levels which may stimulate algal blooms over the warmer seasons. Here the

Moorabool River joins the Barwon River.

Over time the water quality in the Moorabool River has changed. Pre 2011 high salinity was

common due to water extraction and reduced flows associated with the Millennium drought. Post

2011 and with the introduction of environmental flows particularly over summer to autumn helped

lower salinity. Salinity levels were higher in the East Branch (exceeding SEPP (Waters) objective) in

comparison to the West Branch whilst reactive phosphate levels were higher in the West Branch

(exceeding SEPP (Waters) objectives). At the confluence of the East and West Branch the water

quality is maintained at relatively healthy levels, increases in salinity occur downstream, likely

influenced by seasonal flow from the tributaries such as Teatree (exceeding most SEPP (Waters)

objectives) and Sutherland Creeks (exceeding SEPP (Waters) electrical conductivity and dissolved

oxygen objectives), there is evidence during low flow saline groundwater enters these streams. The

implementation of environmental flows improved the overall water quality in the Moorabool River,

particularly the West Branch, whilst over time it appears dissolved oxygen levels have declined

marginally. Near to the confluence with the Barwon River the water quality declines with increased

salinity (exceeding SEPP (Waters) objectives) possibly associated with discharges from the

Batesford quarry.

As the Barwon River makes its way into Geelong after the confluence with the Moorabool River the

water quality marginally declines (marginally exceeding most SEPP (Waters) objectives), increases

in salinity over summer to autumn post 2012 are evident. This increase is likely due to discharge

from the Batesford quarry, dissolved oxygen levels are also marginally lowered. High dissolved

oxygen levels over summer indicate potential algal growth, in the past this section of the Barwon

River through Geelong often experienced algal blooms over summer. The Jerringot and Pakington

St wetlands on the banks of the Barwon River receive urban stormwater runoff, high phosphorus

levels (exceeding SEPP (Waters) objective) are common and may encourage macrophyte and algal

growth. The Waurn Ponds Creek tributary of the lower Barwon River also displays poor water quality

(exceeding some SEPP (Waters) objectives) and at times of low flows has the potential for saline

groundwater intrusion, the creek also has high phosphorus levels.

As the Barwon River enters the estuary at the lower breakwater the water quality is relatively healthy

(marginally exceeding most SEPP (Waters) objectives). During winter, flooding flows in the

catchment completely flush the estuary of saltwater and becomes freshwater dominated, high

turbidity occurs during these times however is only short lived and the tidal salt wedge pushes back

up the estuary. Occasionally over summer as river flow declines and saltwater dominates the effect

of evaporation increases the salinity above that of seawater (hypersaline) in the upper reaches of

the estuary in Lake Connewarre. Also, over summer there can be an increase in algal growth in the

surface waters and on the bottom substrate, at times the bottom waters become super saturated

with dissolved oxygen due to benthic algal mats photosynthesising. As the river exits Lake

72

Connewarre there is evidence of salt wedge development with salinity stratification at times. Water

quality is generally good, though potential algal growth may increase dissolved oxygen levels over

summer and autumn. Turbidity levels (exceeding SEPP (Waters) objective) are likely influenced by

tidal movement out of the shallow Lake Connewarre particularly over summer and the tidal draining

of fringing saltmarsh and mangrove swamps. As the river nears the estuary mouth to Bass Strait the

water quality is very good (within SEPP (Waters) objectives). During seasonal high river flows the

water represents that of freshwater for a brief period, most of the time the water representing that of

seawater due to the strong tidal influence.

The overall water quality of the Barwon River from the headwaters to the mouth of the estuary

indicate the waterway to be in marginal to good condition (marginally exceeding SEPP (Waters)

environmental objectives), influences from most tributaries are evident, displaying areas impacted by

both high and low pH levels, high salinity and turbidity and excessive nutrients such as phosphorus.

High oxygen levels also indicate the potential for algal blooms within the main channel, likely

associated with high nutrient levels particularly in the warmer months for much of its length.

Above: Platypus monitoring site on the Barwon River at Red Gum Island, Geelong. Photo Corangamite CMA

73

Fig

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74

Limitations

The data assessed in this report comprises monitoring results which gives an overall assessment of

the general condition of the water quality throughout the period of monitoring. At times, extreme

events such as floods or blackwater may be missed due to the nature of the monitoring programs.

The duration of exposure to particular poor water quality is also not assessed.

Habitat surveys were conducted at many Waterwatch sites across the Barwon River catchment.

From these surveys the habitat is given a rating. However, the habitat survey does not have clear

quality assurance guidelines to help verify the scores provided. Unfortunately, errors in the

interpretation of the scoring systems and the variability in human perceptions has probably

increased the variance in scoring habitat components and therefore are not included in this report.

In preparing this report, Catchment Ecology Services has relied upon, and presumed accurate, any

information provided by the Corangamite Catchment Management Authority and/or from other

sources. Except as otherwise stated in the report, Catchment Ecology Services has not attempted to

verify the accuracy or completeness of any such information. If the information is subsequently

determined to be false, inaccurate or incomplete then it is possible that observations and

conclusions as expressed in this report may change. Catchment Ecology Services derived the data

in this report from information sourced from the Corangamite Catchment Management Authority and

available on the Waterwatch and EstuaryWatch websites at the time outlined in this report. The

passage of time, manifestation of latent conditions or impacts of future events may require further

examination of the project and subsequent data analysis, and re-evaluation of the data, findings,

observations and conclusions expressed in this report.

Recommendations The monthly monitoring by Waterwatch is vital for assessing the general water quality conditions

within these waterbodies and should be continued. This report has identified times when the water

quality is reduced. At times when particular water quality parameters exceed the expected range

additional monitoring could be conducted to determine if it is localised or throughout the waterway.

Additional monitoring assessing the duration of reduced water quality could also be undertaken

Event based monitoring such as during times of environmental watering and flood events could also

be undertaken to gain a better understanding of how the water quality changes at these times.

An assessment of the daily diurnal nature of dissolved oxygen, particularly in late summer would

provide additional information on the range of values both high and low experienced within each

waterbody.

Several low and high pH values were observed over the assessment period, these times require

additional monitoring to determine the extent and duration of these events, as these times can

potentially lead to the release of metals and nutrients from sediments and increased levels of

ammonia which can be lethal to aquatic organisms.

75

Endnotes

i Upper Barwon, Yarrowee and Leigh rivers FLOWS study update, 2019

https://ccma.vic.gov.au/wpcontent/uploads/2020/04/Upper_Barwon_Yarrowee_Leigh_FLOWS_stud

y.pdf

ii Corangamite CMA Citizen Science Survey Report, 2019

https://www.ccmaknowledgebase.vic.gov.au/kb_resource_details.php?resource_id=4839

iii Corangamite Waterways Strategy (2014-2022) For the health of our rivers, estuaries and wetlands.

Corangamite Catchment Management Authourity. 2013

iv Waterwatch website, 2020 http://www.vic.waterwatch.org.au/

v EstuaryWatch website, 2020 http://www.estuarywatch.org.au/

vi Cesar website, 2020 http://www.cesaraustralia.com/about-cesar/our-projects/the-great-australian-

platypus-search/

vii Australian Platypus Monitoring Network, 2020 https://platypusnetwork.org.au/home

viii The Pesticide Detectives, 2020 https://pesticidedetectives.com.au/

ix The National Waterbug Blitz, 2020 https://www.waterbugblitz.org.au/

x Barwon Estuary Monitoring Pilot Project, 2019

http://www.estuarywatch.org.au/cb_pages/barwon_estuary_monitoring_pilot_project.php

xi Third Index of Stream Condition Report

https://www.water.vic.gov.au/__data/assets/pdf_file/0024/34818/ISC_Part10_Corangamite.pdf

xii Fluker Post website, 2020 http://www.flukerpost.com/

xiii Third Index of Stream Condition Report


xiv SEPP (Waters) (2018). State Environment Protection Policies – Waters. Victorian Government.

October 2018.

https://ccma.vic.gov.au/wpcontent/uploads/2020/04/Upper_Barwon_Yarrowee_Leigh_FLOWS_study.pdf

https://ccma.vic.gov.au/wpcontent/uploads/2020/04/Upper_Barwon_Yarrowee_Leigh_FLOWS_study.pdf

https://www.ccmaknowledgebase.vic.gov.au/kb_resource_details.php?resource_id=4839

http://www.vic.waterwatch.org.au/

http://www.estuarywatch.org.au/

http://www.cesaraustralia.com/about-cesar/our-projects/the-great-australian-platypus-search/

http://www.cesaraustralia.com/about-cesar/our-projects/the-great-australian-platypus-search/

https://platypusnetwork.org.au/home

https://pesticidedetectives.com.au/

https://www.waterbugblitz.org.au/

http://www.estuarywatch.org.au/cb_pages/barwon_estuary_monitoring_pilot_project.php


http://www.flukerpost.com/


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