Living Murray Icon Sites
eWater CRC worked on water-management issues for The Living Murray icon sites, in partnership projects with relevant organisations.
eWater partners developed software that can be applied at the icon sites to quantify the ecological benefits of different potential watering regimes.
The process allowed eWater’s model developers to ‘road-test’ the software, and adapt it so that it may be applied to other similar ecological assets.
Licensed from the Murray–Darling Basin Authority under a Creative Commons Attribution 3.0 Australia Licence
About the Focus Catchment
The Living Murray is one of Australia’s most significant river restoration programs. It aims to achieve a healthy working River Murray system for the benefit of all Australians by returning water to the river’s environment. The Living Murray program was established in 2002 in response to evidence showing the declining health of the River Murray system (for more information, visit www.mdba.gov.au/programs/tlm).
Through ‘The Living Murray’, the Murray Darling Basin Authority (MDBA) has set a goal to return an average of 500 GL per annum of environmental water to six icon sites in the Murray system: the Barmah-Millewa Forest; Gunbower and Koondrook- Perricoota forests; Hattah Lakes; Chowilla Floodplain and Lindsay-Wallpolla Islands; the Murray Mouth, Coorong and Lower Lakes; and the River Murray Channel.
Each of the icon sites is unique and therefore the impact of water allocation will be different at each site. The Barmah-Millewa Forest is Australia’s largest river red gum forest and the biggest ecosystem of its type in the world. The Gunbower-Koondrook-Perricoota forests contain wetlands that are important breeding places for waterbirds and native fish. They are also an essential destination for waterbirds, many of which are protected under treaties with Japan and China. Hattah Lakes — the initial focus for the eWater work — is a unique collection of semi-permanent lakes that support river red gums, as well as being an important breeding habitat for waterbirds. The semi-arid Chowilla Floodplain and Lindsay-Wallpolla Islands retain much of those areas’ natural character and support a diverse range of plants, animals and native fish species. The Lower Lakes, Coorong and Murray Mouth form a unique estuarine system that covers 23 different wetland types and is an important environment for a wide range of waterbirds and native fish. The River Murray Channel links the forests, floodplains, wetlands and estuaries along the Murray and provides habitat for many native plants, fish and animals.
eWater used its ecological water modelling software to apply existing and newly developed models to predict the consequences of different watering scenarios for fish, birds and vegetation at Hattah Lakes, and at the other five icon sites if time permits.
The current process for prioritising environmental water allocations for the icon sites involves the Icon Site Managers putting forward priority watering proposals for their sites, and then the Environmental Watering Group prioritising the watering actions based on a set of criteria that include urgency of need.
The implementation of watering actions is currently based on local knowledge and scientific advice. However, this application of eWater’s ecological modelling software will produce summaries of predicted ecological responses, based on explicit scientific representations of the river system, to better inform the decision-making process.
How eWater is helping
The team applied an eWater software tool that models ecological responses to watering scenarios for natural ecological assets, such as the icon sites. The tailored tool will provide information that could assist The Living Murray managers in prioritising deliveries of environmental water.
Addressing the Hattah Lakes first, the tool will convert daily data from river flow scenarios (via the MDBA model ‘MSM Bigmod’) into measures of environmental consequence.
Typical scenarios include return of additional water to the system, and the operation of new engineering controls.
An example of a measure of environmental consequence would be the number of days at which water levels can support successful bird breeding or fish spawning.
Having a set of measures that predict the environmental effects of various watering scenarios gave Icon Site Managers a numerical basis on which to rank watering proposals.
Data and conceptual models are already available from the previous environmental water allocation studies and scientific reviews that led to the decision to return water to the River Murray. These resources are being compiled and built into the modelling software. Further data collection is underway, together with further conceptual modelling of ecological responses to flow at Hattah Lakes, and this will extend to other icon sites if time permits.
eWater tested and calibrated the ecological response models that emerge, and the team will build specific reporting and interpretation tools to communicate the outputs.
The Living Murray aims are being advanced by this application, which gives the MDBA a potential ongoing capability to manage the water needs of the icon sites according to the amount of water available.
While this work is specific to the needs of the icon sites, eWater’s software models are being developed in such a way that the general approach and information requirements may be useful in comparable situations elsewhere.
These partner organisations are involved in this project:
Murray-Darling Basin Authority (MDBA)
Murray-Darling Freshwater Research Centre (MDFRC)
NSW Dept of Water Management
University of Canberra