Research focus: Environmental Water

The Environmental Water theme developed a detailed understanding of the ecosystems of our major water resources including the River Murray and the wetland systems in the South-East of South Australia.

These systems contain several RAMSAR wetlands of international importance which required a robust integrated management approach to maintain the environmental values of these regions while also achieving social and economic outcomes.

The Goyder Institute demonstrated the value and effectiveness of its collaborative research approach by quickly responding to urgent and time-critical opportunities such as the 2010 floods and the consultation and review processes of the Murray Darling Basin Plan development.

Goyder Institute advice underpinned the South Australian Government’s successful negotiation of the Basin Plan resulting in $1.77 billion in additional funding to return 3200 GL of water to the environment, and to remove constraints that impede delivery of that water.

This research produced a series of reports, publications and research materials:

• Model Metadata Templates
• Technical Reports

Murray Darling Basin Plan and Review

The Murray Darling Basin Plan was signed into law in December 2012 and the Goyder Institute was involved with the analyses of the consequences of this Plan from very early on:

1. In November 2010 the South Australian Government invited the Goyder Institute to review the Guide to the Proposed Plan and to determine whether the proposed sustainable diversion limits would meet the Government’s environmental water requirements and improve or maintain water quality. The project produced a synthesis report that describes the findings of the science review.
   
2. The draft Basin Plan was released for consultation in November 2011 and the South Australian Government sought advice from the Goyder Institute on the likely ecological consequences for South Australia of the proposed Plan. The Goyder Institute assembled an Expert Panel to review the science underpinning this assessment for South Australian environmental assets. The Expert Panel report recommended that a wider range of possible scenarios be evaluated including additional volume and the relaxation of constraints.
   
3. Following the modelling of additional water recovery scenarios by the Murray Darling Basin Authority, a detailed evaluation of the model outputs was undertaken by SA Government scientists and peer-reviewed by the Goyder Institute.

This work by the Goyder Institute provided the South Australian Government with the necessary confidence about the quality of the assessments and the science that was used to underpin policy development, to support the negotiations with the Federal Government for a better plan that delivers enough water for the health of the river and its floodplains.

River Murray Catchment Program and e-water management

Murray Flood Ecology

A better understanding of the ecological responses of the River Murray and its floodplains to flooding has provided new knowledge for the development of annual and long-term watering plans under the Murray Darling Basin Plan. To achieve the greatest ecological benefits from available environmental water in the River Murray, it is vitally important to know how the biological systems respond to various flow scenarios (e.g. timing, volumes, duration, frequency, flow rates etc).

Flood flows returned to the Murray-Darling River in 2010 after the Millennium Drought enabling Goyder Institute scientists to undertake an analysis of how the river channel, floodplain vegetation and fish populations respond and recover when water is restored to the system after such a long period of drought.

Immediately following the floods in 2010, the Goyder Institute undertook a field study to investigate the change in abundance and species diversity of native fish populations in the lower River Murray during these changing hydrological conditions. The results have been published in a technical report entitled From drought to flood: annual variation larval fish assemblages in a heavily regulated lowland river.

The larger investigation includes a number of reports detailing the scientific findings from a number of the components of the research including fish, vegetation, metabolic activity.

Research requirements for e-water management in the South Australian Murray Darling Basin

This project focussed on the entire SA MDB including the riverine, floodplain, wetland habitats and the Coorong and Lower Lakes. The primary aim of the project was to identify research that is required to support decisions regarding the provision of environmental water.

This was achieved by:

• Assessing the decision support requirements of environmental water management in the SA MDB;
• Identifying key ecological knowledge gaps by developing conceptual hydroecological response models; and,
• Developing an indigenous engagement framework.

The information was brought together in an adaptive management framework that can:

• Inform decisions regarding environmental water provision at the landscape scale in the absence of more sophisticated tools;
• Guide priorities for future research and monitoring projects; and,
• Provide a foundation for the development of more sophisticated decision support systems.

A scoping report was developed synthesising the existing knowledge and recommending areas to focus further research.

South East research program

Groundwater supports the economic base of the South East through irrigation, town and industry water supplies. The water resources of the South East need to be managed as a holistic system, recognising the interconnection between surface water and groundwater to maximise the economic and social benefits of regional water resources and to ensure adequate environmental water provisions to the region’s wetland systems including the Coorong.

South East Regional Water Balance

This project laid the foundations for the development of a regional water balance model, to facilitate future water allocation planning for the Lower Limestone Coast region. It consisted of the development of a regional water balance framework and a preliminary assessment of the spatial variability and indicative fluxes of groundwater discharge to the marine environment. It also included an assessment of the role of geological faults on regional groundwater flow and inter-aquifer leakage. The major output from this work was a framework for the development of a regional numerical groundwater flow model for the Lower Limestone Coast region. This comprises the datasets, conceptual model and the suggested approach for the full development of a fit-for-purpose regional model.

Improved Modelling of the Catchments and Drainage Network in the Upper South East for Management Outcomes

This project developed a software tool based on conceptual and stochastic modelling designed to improve confidence in flow volumes that can be expected along Drain M, located in the Lower South East. This tool enabled a season to be assessed and then translated into a seasonal operational plan, while providing clear information for decision-making. The model allowed water volume information to be estimated in order to support decisions about optimisation of environmental water requirements for a number of regional assets, including Lake George.

Developing ecological response models and determining water requirements for wetlands in the South East of South Australia

This project provided information on wetland ecosystem response to changes in water quantity and quality (salinity). Eco-hydrological conceptual models were created to describe the response of wetland plant assemblages for selected wetland sites to altered hydrological conditions. This involved determining historical trends in wetland plant assemblages in response to hydrological regimes using remote sensing techniques, and identifying thresholds for changes in habitat and wetland plant assemblages in response to principal drivers of wetland type (e.g. changes in water and salinity regime). A classification system for wetlands and vegetation assemblages was also developed as a basis for applying conceptual models of different wetland types at a landscape scale.

Riverbank Collapse

This three-year project provided a clear understanding of the processes that trigger riverbank collapse.

It stems from the many bank collapses at various parts of the lower River Murray from Blanchetown to Wellington during the 2009/2010 drought when the river was at one metre below sea level and about two metres below its normal level. 

The River Murray is one of the few river systems in the world that can fall below sea level because of the barrages preventing the inflow of sea water during low river flows, but there is limited recorded evidence of previous collapse incidents.

At the end of the project researchers defined safe operating levels for the river, allowing management and intervention by State and Local Government. They also established long-term sustainable options for higher risk sites.

Other outcomes included:

• the ability to reliably predict conditions that may led to future riverbank collapse;
• identifying remediation options for repair and protection of affected and vulnerable sites;
• site-specific sustainable management strategies to ensure public safety;
• improved river management and policies to avoid critical water levels; and,
• better information for the community and government agencies.