Characterising ecohydrological benefits in the Murray-Darling Basin
The Murray-Darling Basin Plan sets targets for measuring progress towards environmental objectives for water-dependent ecosystems, and these are supported by more specific operational strategies for delivering environmental water. The challenge is in understanding, evaluating and communicating the ways in which people benefit from these ecological objectives being met. This is important because there has been substantial public investment in water reform over many years, there are strong and contested values at play, people depend on a ‘healthy working basin’ and there is a needed for trusted, evidence-based ways to assess and report on the impacts on people.
Various benefits of environmental flows to communities and the environment. PHOTO: Tanya Doody
People perceive benefits when outcomes align with their own values, and so the evidence needed goes beyond biophysical characterisations of hydrology and ecological response to connect to people’s experience and values. For this reason, the research team includes both hydro-ecological and social science expertise, as well as experience in bridging the biophysical and social sciences. We chose an approach that readily represents multiple beneficiaries who may have different values and are affected in different ways, and can also capture both beneficial and detrimental outcomes for people.
Science and Innovation
Our response has been firstly to recognise a familiar ecosystem services ‘cascade’ that links environmental processes and functions to ecosystem services, benefits and beneficiaries. Doing so provides a clear framework for articulating assumptions and associated causal logic, so providing guidance on what data and evidence to seek in order to characterise complex relationships between water management and impacts experienced by people.
The ecosystem services framework alone is not sufficient for effectively communicating rich relationships between water and people, and so we used the framework to acquire the data and evidence needed to create a narrative relating water management to social outcomes for one test case. The narrative describes the relationship between the condition of River Red Gum forests and the contribution they make to rural amenity and, in turn, the liveability of rural towns along the River Murray.
The work is preliminary and exploratory in nature. In working with the MDBA on this test case, together we have learned more about the challenges in acquiring the data needed to relate changes in flow to changes in benefits experienced by people. For example, in relating biophysical flow attributes to vegetation condition, then relating condition to ecosystem services that contribute to amenity benefit experienced by people, we are spanning many fields and it is difficult to characterise the links in ways that allow us to attribute changes in flow to changes in benefits. We are in the process of evaluating lessons learned in order to design next steps for the work to proceed.
Future pathways to impact include:
- When it comes to communicating impacts of environmental watering more broadly, it will be important to be able to take science-based narratives and use that material in more sophisticated ways, tailored to different audiences. There is scope to test narratives with different audiences, and the levels of support for different narratives could be useful data for evaluating the credibility and effectiveness of narratives.
- Future flow regimes will be shaped by basin-wide environmental water strategies, and these in turn will be influenced by climate change and a complex suite of water-related priorities across the Basin. In a related project, CSIRO and MDBA are developing the tools to explore potential trajectories of change for vegetation communities, drawing on knowledge of the response of River Red Gum to historical changes in the flow regime. While the Basin Plan and the basin-wide environmental watering strategy set specific targets for vegetation communities, there are many options for how plans and strategies are implemented on the ground. Tools for exploring different climate and environmental watering strategies through modelling scenarios create the opportunity to link specific actions to trajectories of tree condition. Having these trajectories available at multiple locations along the river will allow changes in vegetation condition to be linked to liveability and amenity consequences for specific towns and communities. Under different watering strategies some communities may stand to benefit more than others, and some values within communities will be realised more than others. These distributional considerations warrant exploration and deliberation with those who stand to be affected, and tools that link and communicate future trajectories provide a vehicle for such deliberations.