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Sustainable Rivers Audit 2 (SRA2)

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Murray-Darling Basin Authority

Latest documentation


Designed for use in

ACT, Australia
New South Wales, Australia
Queensland, Australia
South Australia, Australia
Victoria, Australia



Assessment purpose

Management effectiveness, Processes and components

Assessment criteria

Physical and chemical, Flora, Fauna

Method type

Field, desktop, expert panel


Long term – The SRA was originally designed to operate on a six-year cycle, with the most comprehensive reports issued at the end of each cycle. Annual reporting is precluded by limited resources and capacity. Individual Themes address ecological patterns and processes operating over different scales of time and space, therefore annual reporting will be more relevant for some Themes
(e.g. Macroinvertebrates) than others (e.g. Physical Form).

SRA 1: 3 years
SRA 2: 2 years



Wetland system


Description and method logic

Method purpose

The Murray-Darling Basin is a network of streams and rivers across four states. To understand large-scale changes and to effectively manage the Basin's river resources, the Sustainable Rivers Audit (SRA) was designed to measure the health of the rivers at the basin scale.

The SRA was designed to give river managers and users unbiased information and provide an integrated assessment of river health. It provides an insight into the variability of river health indicators across the basin and over time and may trigger changes to natural resource management by providing a more comprehensive picture of river health.


The SRA provides assessments of ecosystem health for each of the 23 major river valleys of the Basin. Using data gathered in 2008–2010 on fish, benthic macroinvertebrates, riverine vegetation, physical form and hydrology. A first step was also made in describing trends in condition of fish, macroinvertebrates and hydrology, based on a small number of observations through time.

The first stage of the SRA took place over 2004-2007. The second stage (SRA2) was concluded after the 2008-2010 period, and provides recommendations for future large-scale condition surveillance reports.

Method logic

The SRA gathers quantitative information on environmental indicators in valleys throughout the Basin.

The indicators provide ‘windows’ on components of the river ecosystems, and are grouped as Themes. The data for each Theme are acquired systematically using agreed protocols, with quality assurance. The Themes used are:
  • Fish
  • benthic Macroinvertebrates
  • riverine Vegetation
  • Physical Form
  • Hydrology.

Within each valley there are 1–4 zones, defined in most cases by altitude. Sampling locations are either located randomly across the river network within zones, or constitute a comprehensive census across each valley’s river system.  Enabling unbiased statistical analyses and representative reporting.

The indicators are combined (or integrated) to form quantitative measures of condition for each Theme, and Theme Condition ratings are combined to assess Ecosystem Health for each valley and its zones.

Condition assessments for each valley are related to a benchmark called Reference Condition. This estimates the status of a component (for example, the value of a measure of the fish community) as it would be in the absence of significant human intervention in the landscape. Reference Condition is a benchmark representing the river ecosystem in good health. It is not used as a target for management.

Condition of each Theme is rated on a five-point rating scale from Good through Moderate, Poor, Very Poor to Extremely Poor, depending on how different the Theme components are from their respective benchmarks. The same scale is applied to Ecosystem Health.

Criteria groupings of the method

Assessment criteria are based on 5 themes: fish, benthic macroinvertebrates, riverine vegetation, physical form and hydrology.

Data required

  • Fish: Fish Condition Index, field and trend data
  • Macroinvertebrates: Macroinvertebrate Condition Index, field and trend data
  • Vegetation: Vegetation Condition Index, LiDAR data
  • Physical form: Physical Form Condition Index, LiDAR data and modelling outputs
  • Hydrology: Hydrology Condition Index, flow data and modelling outputs

Resources required

Expertise required

High level expert knowledge, expert panels for fish, macroinvertebrates, vegetation, physical form and hydrology themes. The ability to use and make sense of historical, spatial, non-spatial, and modelling data. The ability to undertaking sampling and site assessments.

Materials required

Each criteria theme requires a suite of resources. In addition to persons and equipment for physical sampling in 23 valleys, the methodology also requires LiDAR datasets and SedNet and Bayesian modelling for physical form survey, LiDAR datasets for vegetation mapping, and hydrological flow metering and modelling.

Method outputs


  • Audit reports by Independent Sustainable Rivers Audit Group (ISRAG)


  • Provide information about trends in river health along rivers and over time
  • Identify where investment in management actions will provide the greatest benefits in protecting or restoring poor river health
  • Assist in guiding long term river health initiatives
  • Standardise and integrate river monitoring across state boundaries
  • Raise community awareness about the condition and importance of river health
  • State of Environment reporting.

Criteria by category

    Physical and chemical

    • Hydrological theme (Hydrology Condition Index)
      • In-Channel Flow Regime A (volume and flow events)
      • In-Channel Flow Regime B (seasonality and variability)
      • Over Bank Floods, High
      • Over Bank Floods, Low
    • Physical form theme (Physical Form Condition Index)
      • Bank Dynamics indicator
      • Bed Dynamics indicator
      • Channel Form indicator
      • Floodplain form


    • Vegetation theme (Vegetation Condition Index)
      • Abundance and Diversity indicator
      • Quality and Integrity indicator


    • Fish theme (Fish Condition Index)
      • Fish Expectedness
      • Fish Nativeness
      • Fish Recruitment
    • Macroinvertebrate theme (Macroinvertebrate Condition Index)
      • SimOE score community composition (compared to reference)


Recommended user

River managers, community, water users, policy makers.


  • Provides a standard framework across the Basin
  • Involves partner agencies in each state
  • Can detect large-scale changes happening over time
  • Independent assessors
  • Indicators were chosen for their cost effectiveness
  • SRA 2 includes additional criteria themes.


  • Uses modelled evidence for some reference conditions
  • Does not assess other system types.

Case studies



  1. Davies, P, Stewardson, M, Hillman, T, Roberts, J & Thoms, M (2012), Sustainable Rivers Audit 2: The Ecological health of rivers in the Murray-Darling Basin at the end of the Millenium Drought (2008-2010). Volume 1.. [online], Murray-Darling Basin Authority, Canberra. Available at:

Last updated: 9 April 2019

This page should be cited as:

Department of Environment and Science, Queensland (2019) Sustainable Rivers Audit 2 (SRA2), WetlandInfo website, accessed 27 October 2023. Available at:

Queensland Government
WetlandInfo   —   Department of Environment and Science