Index of Stream Condition The Third Benchmark of Victorian River Condition ISC3 Ministerial Foreword The Hon Peter Walsh MLA The Hon Ryan Smith MP Healthy rivers are important to all Advancing the use of remote sensing technology for the ISC continues to improve Victoria’s approach Victorians and communities are always to collecting river condition data and management keen to know more about the condition of regional waterways. of their local waterways. Condition monitoring is just one part of the broader Victorian Waterway Management Program, which aims Comprehensive and up-to-date information about the to improve the environmental condition of waterways to condition of Victoria’s rivers also is vital to support the support environmental, social, cultural and economic development of state policy and regional waterway values. Other elements of the program include: management programs and to assess progress against targets for improving river health. • a state policy framework with an evidence-based, adaptive management approach; The Index of Stream Condition (ISC) report reveals that waterway health has remained stable and there • new regional Waterway Strategies being prepared to have been no substantial changes in condition since identify priority management activities in each region the second benchmark in 2004. for the next eight years; Across Victoria, 23 per cent of stream length • more than 600 GL of environmental water held by assessed was in good or excellent condition. This is the Victorian Environmental Water Holder; and an encouraging finding because data for the 2010 • significant Victorian Government commitment benchmark was collected over a six-year period that and investment to improve waterway condition coincided with the prolonged drought, from 1997 since 2011. to 2009. All of these activities play a vital role in maintaining This third ISC benchmark report is another valuable the health and resilience of our waterways. The next addition to Victoria’s waterway reporting. The ISC step is to work with local communities to build on this provides a state-wide snapshot of river condition result, particularly through the ten regional Waterway and data, providing a good understanding of Strategies, which are now being developed to guide the ongoing river health. Victorian Government’s continuing investment in priority A major advancement for the third benchmark report waterway health programs. has been to use remote sensing technology to cover This report is an important source of information for 29,000 km of rivers and streams across Victoria. the future management of Victoria’s rivers and we This exercise has been the largest operational congratulate everyone who has contributed to its demonstration of this type anywhere in Australia. compilation. We encourage you to read this report This approach has delivered an unprecedented and learn more about the health of your local rivers. amount of data on the condition of our major rivers and streams. In addition, the remote sensing data is The Hon Peter Walsh MLA being used to improve flood risk mapping and flood Minister for Water warning systems, which will significantly cut the cost of floods to the community and the government. The Hon Ryan Smith MP Minister for Environment and Climate Change Contents Introduction and history 2 North East Region 14 Goulburn Broken Region 26 North Central Region 36 Mallee Region 48 Wimmera Region 58 East Gippsland Region 68 West Gippsland Region 80 Port Phillip Region 92 Corangamite Region 106 Glenelg Hopkins Region 120 Appendix 1 131 Appendix 2 132 Cover Images: LiDAR image, lower Ovens River. Courtesy Christina Ratcliff. Genoa River. Courtesy Sean Phillipson. Goulburn River. Courtesy Alison Pouliot Introduction In 1999 the Victorian government in conjunction with the Catchment and history Management Authorities (CMAs) undertook the first statewide benchmark of the environmental condition of Victoria’s major rivers and streams. Introduction and history This was an important milestone as it • a standardised interpretation of river health that has allowed communities to understand and get involved was the first complete and comprehensive in regional river health discussions assessment of the environmental condition • a way to assess the long-term effectiveness of river of rivers anywhere in Australia. management programs. The benchmarking process was undertaken using the The ISC is much more than just a monitoring program that first integrated measure of river condition – the Index of benchmarks the condition of the State’s major rivers and Stream Condition (ISC). The ISC provides information on streams. It is a vital component in the adaptive management five key aspects (see Figure 1) of river condition: hydrology, framework for waterway management in Victoria. The ISC streamside zone, physical form, water quality and aquatic provides data and information that feeds into the CMA life. This information is then combined to give an overall regional Waterway Strategies and is used to help prioritise measure of environmental condition. CMA work programs. Over the longer term the ISC program will be able to assess changes due to management To date, the ISC benchmarking process remains the only intervention (such as revegetation, weed control, delivery of ongoing statewide assessment of river condition in Australia. environmental water). To achieve this, the ISC benchmarking A second ISC benchmark was undertaken in 2004 and this, process will need to continue to evolve and move away from the third ISC benchmark, in 2010. only reporting at the reach scale to also report at smaller Over the past 15 years, the ISC benchmarking process scales and to change from assessing the environmental has provided: condition of rivers and streams against reference river condition to assessing against management targets. • a consistent statewide picture of river condition The results of this third ISC benchmarking exercise – • a consistent approach to the identification of river the 2010 ISC - are summarised in this report and are values and threats available at the Department of Environment and Primary • statewide data that has been incorporated into the Industries web site http://www.depi.vic.gov.au/water/ CMA regional Waterway Health Strategies water-resource-reporting and follow the link to the Index of Condition site. Bemm River in East Gippsland. Courtesy of Graeme Dear Index of Stream Condition The Third Benchmark of Victorian River Condition 3 The ISC Concept This report presents the results from the third statewide A number of metrics are combined to characterise each benchmark of the condition of Victoria’s major rivers and sub-index (see Figure 1 and Appendix 1). A total of 23 streams using the Index of Stream Condition. The first metrics are used and each of these is considered important two ISC benchmarks were in 1999 and 2004. from a statewide perspective. The ISC is evaluated for sections of a river known as a ‘reach’. Reaches are typically The ISC brings together data from a variety of sources to between 10-30 km in length and with a similar flow regime, give a detailed overview picture of river and stream condition vegetation and landscape characteristics. across the State. The ISC is made up of five sub-indices – hydrology, streamside zone, physical form, water quality and aquatic life. Figure 1: The 2010 Index of Stream Condition sub-indices and metrics Hydrology Physical Form Streamside zone Water Quality Aquatic Life Hydrology refers to the Physical form takes into Streamside zone Water quality is the Aquatic life is based amount of water that is account the river bank measures characteristics quality of water in on the number and within the river channel condition as well as of the woody vegetation the river. type of aquatic at a particular point instream habitat (logs within 40 metres of the macroinvertebrates in time at a particular or ‘snags’) and major river’s edge. found within the river. location. A minimum of barriers to fish migration, 15 years of monthly flow such as dams and data is used. artificial weirs. • Low flows • Bank condition • Width • Total Phosphorus • AUSRIVAS • High flows • Artificial barriers • Fragmentation • Turbidity • SIGNAL • Zero flows • Instream woody • Overhang • Salinity (EC) • EPT • Seasonality habitat • Cover of trees • pH • Number of Families • Variability and shrubs • Structure • Large Trees • Weeds The ISC score for each river reach is presented as a bar Each river reach assessed is given an overall ISC score of graph of the five sub-indices, as shown in Figure 2. between 0-50. This score is then categorised into one of five broad condition bands – excellent, good, moderate, poor or very poor. It is important to emphasise that while the condition band is useful in summarising the overall condition of a river reach, it is the details (sub-index and metric scores) that are used to better understand the issues affecting the condition of a reach and are used in river planning and Figure 2: The ISC bar showing the 5 sub-indices management. Length of bar represents Display legend of sub-indices sub-index value (maximum 10) Sub-index value Hydrology Physical Form 8 6 9 3 7 Streamside Zone Water Quality Total bar length is maximum Aquatic Life Length of bar represents Display legend of sub-indices possible value (50) sub-index value (maximum 10) Sub-index value Hydrology Physical Form 8 6 9 3 7 Streamside Zone Water Quality Total bar length is maximum Aquatic Life possible value (50) 4 Index of Stream Condition The Third Benchmark of Victorian River Condition Introduction and history Reference condition The majority of river condition assessment techniques For the 66 ISC river reaches that had priority watering adopt what is termed a ‘referential approach’. This is where actions listed in the 2011 – 2012 Seasonal Watering Plan the current river condition is compared against its reference (Victorian Environmental Water Holder 2011), the agreed condition. This reference condition is generally accepted priority watering actions were used as the management to be what a river would have looked like in its undisturbed targets.