Australian Capital Territory

State of the Environment 2015

Red-Necked Wallaby – endemic to south-east Australia. This wallaby is very common in the mountains west of Canberra, but is less often seen in the drier, more open woodlands of Canberra Nature Park. This species is not considered to be endangered or threatened. Photo: Leo Berzins
Recommendations
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11.6 Water

11.6.1 Progress against 2011 recommendations

The 2011 State of the Environment Report1 recommended that the ACT Government should:

  • establish cross-boundary management of the ACT’s water resources, including
    • developing catchment policy and an integrated water supply catchment management strategy, as recommended in previous State of the Environment reports
    • strengthening integrated management action by facilitating improved exchange and use of information, such as spatial information, between government agencies, NRM groups and Catchment Management Authorities, and by promoting sustainable catchment management with landholders and the community
  • complete an assessment of the ACT’s at-risk groundwater resources
  • update water management, monitoring and reporting programs to inform
    • actions to mitigate impacts of urban development on water quality
    • the efficacy of water-sensitive urban design measures
    • improvements in sediment and erosion mitigation actions
    • the management of ACT lakes.

The Commissioner’s report on an investigation into the state of water courses and catchments for Lake Burley Griffin (published in April 2012) focused on the lake itself, but also included some broader recommendations on urban and rural catchment management and improved coordination of catchment management.

Recommendations on urban catchment management included the development of a strategic approach to water-sensitive urban design, including:

  • ensuring that water-sensitive urban design requirements are enforced
  • monitoring the effectiveness of existing water-sensitive urban design infrastructure, including the efficacy of existing gross pollutant traps
  • comparing ACT approaches with other jurisdictions.

Recommendations on rural catchment management included:

  • on-ground actions to reduce the potential for soil erosion within the catchment area of Lake Burley Griffin by the ACT and NSW governments, with support from the National Capital Authority
  • investigation of the role of Jerrabomberra Wetlands watercourses in improving water quality in the catchment.

Recommendations to improve the coordination of catchment management included the establishment of a Burley Griffin–Molonglo–Queanbeyan Catchment management agreement between the ACT, NSW and Australian governments to include strategic objectives for the integrated coordinated management of the lake and catchments.

Most of these recommendations are addressed through work being undertaken as part of the new ACT Water Strategy and the ACT Basin Priority Project. Significant progress has been made against these recommendations during the reporting period:

  • ACT Water Strategy, August 2014,8 includes outcomes, strategies and actions to guide water management across the ACT and region, including catchment management, storm water and flood management, water supply and services, water for the environment, recreational water use, and public health.
  • Cross-boundary management of water resources
    • Catchment management arrangements have been established that better integrate water and land management, and improve the ACT spatial planning framework for NRM to inform management of land, water and biodiversity.
    • The ACT and Region Catchment Management Coordination Group has been established, with a focus on improving cooperation, coordination and alignment of effort in regional catchment management issues; the priority action of the group is to develop a regional integrated catchment management strategy.
  • Water supply
    • The enlarged Cotter Dam and the Murrumbidgee to Googong pipeline have ensured that current potable water supply challenges have been met.
  • Groundwater resources
    • An updated report (August 2013) on groundwater recharge rates in the subcatchments – with the majority of abstraction bores and covering a full range of conditions from extreme drought to a La Niña high-rainfall cycle – validated previous calculations on subcatchment recharge rates. Only a few low-volume bores have been installed during the past two years and these have not significantly increased the risk profile of the subcatchments.
  • ACT Basin Priority Project
    • The first phase of an Australian Government–funded project to improve water quality leaving the ACT – a comprehensive ACT-wide water quality monitoring program with a focus on six priority catchments – has been implemented. The six priority catchments are Lower Molonglo (new development); Upper Molonglo (source water); Tuggeranong (lake); Yarralumla Creek (infill/developed); Riverview, West Belconnen (greenfield development); and Fyshwick (industrial/wetlands development).
    • The water quality monitoring program is updating and realigning existing monitoring arrangements to reflect changes in land use and technology. As well as addressing water quality monitoring across the ACT, more intensive monitoring is occurring in the six priority catchments, as well as a detailed audit of the performance of existing infrastructure.
    • An investigation, audit and analysis of ACT Government water quality infrastructure assets was conducted to assess the effectiveness of existing water quality infrastructure and recommend possible improvement opportunities.
  • Catchment management
    • In August 2014, the Government released the report of the review of water-sensitive urban design regulations in the ACT. Research was also undertaken on water-sensitive urban design implementation in other jurisdictions, and its influence on housing affordability and recommendations are being implemented
    • Land managers have implemented on-ground projects to improve management, monitoring and reporting, including the installation of 12 groundwater and 6 surface water monitoring stations at Jerrabomberra Wetlands, allowing development of a model for groundwater and surface water movements across the wetlands. They are managing an additional 20 000 hectares after the construction of the enlarged Cotter Dam and the Googong Foreshores. The focus is to ensure water quality is not compromised by threatening processes such as environmental weed invasion, erosion and sedimentation, vertebrate pests and inappropriate visitor interaction.

11.6.2 Justification for the 2015 recommendation

Although most water resource indicators in the ACT are in a very good or good state, some are not and warrant some special attention. These are total nitrogen levels, which are in a very poor state; and turbidity, chlorophyll-a and ecological condition, which are in a poor state.

Assessing and managing the longer-term consequences of this condition is of high importance. In some cases, it may not be possible to quickly reverse the situation. Long-term strategic management and, possibly, land-use change – neither of which may be feasible – may be needed. Consequently, developing strategies and actions to improve these aspects of water quality should be a high priority.

The location of sampling points is also important to consider. For example, Australian River Assessment System Observed:Expected scores, turbidity and chlorophyll-a samples, which were all assessed as being in a poor state during the current reporting period, were predominantly taken from areas where land-use pressures are the most intense in the ACT (ie urban and agricultural areas). If more samples were taken in conservation areas, then the percentage of sites classified as exceeding guideline levels would likely be much lower. In an overall assessment of water resource indicators, the proportion of sampling points in different environmental and land-use settings should therefore be considered.

Most water resource indicators had a good amount of data available. The data available for these indicators were collected at regular intervals (eg multiple times in every year of the assessment) and collected in many places across the ACT. For the state and trend of water resources in the ACT to be efficiently and effectively monitored into the future, it is essential that the current monitoring network be maintained.

In contrast, data related to groundwater availability and quality were relatively limited. There seems to be a limited number and spread of bores, with much data collected outside the current reporting period. However, given the current limited use of groundwater in the ACT, this is not an issue. In the future, if groundwater use increases or pollution continues, then more extensive groundwater monitoring may be required. It is also important that monitoring of rainfall and groundwater levels occurs at each monitoring site to better understand the long-term relationship between rainfall and groundwater recharge.

Understanding the links between pressures and the state and trend of water quality indicators will become increasingly important as these pressures intensify. This is expected through the increased land-use change and water resource development needed to support our growing population, and the changing rainfall patterns under climate change. Without understanding the driving mechanisms behind each indicator, it can be difficult to manage water quality into the future. The strategic collection of long-term data on indicators and pressures is critical. This information will help in the assessment of the state and trend of water resources. Importantly, it can also help model the relative importance of different drivers of water resource conditions and determine the most effective management action.

Recommendation 7

That the ACT Government assess the consequences of, and understand the driving mechanisms behind, the poor condition of water resources as shown by the indicators for total nitrogen, turbidity, chlorophyll-a and ecological biodiversity, and assess the need for collecting more information for indicators with little available data.

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