By Emeritus Professor Angela Arthington
One of the grand research challenges of the Australian Rivers Institute is “Balancing water needs for humans and nature”. Meeting human needs for freshwater is essential, but alteration of river flow regimes by dams and water extraction for human use has impacted freshwater and coastal biodiversity and ecosystem condition on a global scale.
As freshwater ecosystems degrade through barrier effects and changes in water regime, species are lost; human communities lose important social, cultural, and economic benefits; estuaries lose productivity; invasive plants and animals flourish; and the social-ecological resilience of riverine, wetlands and estuarine ecosystems weakens. We can all identify such cases from our research and travels.
How much water does a river need?
This question emerged in 1997 during work by The Nature Conservancy on rivers with altered flow regimes. It stimulated river scientists and water managers to progress from thinking about water quantity to the concept of environmental flow regimes suited to the climatic setting, hydrology and related ecological processes of individual rivers and wetlands.
The term environmental flows became commonplace in research, implementation projects and water management policies. Many advances in methods to assess environmental flows were followed by case studies of environmental water allocations. Australia made great contributions and progress during this era.
The Brisbane Declaration (2007)
In 2007 the Brisbane Riversymposium partnered with The Nature Conservancy to run the first international conference on environmental flows.
This fabulous event (held on the banks of the Brisbane River) produced The Brisbane Declaration (2007), setting out a global action agenda that addressed the urgent need to protect river flows globally.
The Declaration defined the environmental flow of a river as “the quantity, timing, and quality of water flows required to sustain freshwater and estuarine ecosystems and the human livelihoods and well-being that depend on these ecosystems”.
This definition has been widely cited and accepted universally. Numerous research projects and implementation initiatives have tested and strengthened the scientific basis and methods of environmental flows. Three new books (see the end of this post) added to the wealth of literature. Environmental water requirements were incorporated into high-level policies and platforms, such as the European Union Water Framework Directive. Many countries now formally protect and manage environmental water through national laws and regulations.
Challenges for Environmental Flows
Progress with environmental flows science and water management since 2007 has been immense. Yet major challenges remain in protecting and restoring the integrity of freshwater ecosystems and the ecological services that sustain human societies and economies.
These are the main issues:
- The world is experiencing a renewed period of dam building, and much of this is concentrated in ecologically sensitive river basins (Amazon, Mekong, Congo) where dams will act as barriers to fish and other migrations, and fragment formerly connected populations.
- Globally, 48% of river volume is moderately to severely impacted by either flow regulation, fragmentation, or both, and this proportion will nearly double if all dams planned and under construction are completed.
- Human water demands continue to grow in most parts of the world.
- Climate change heralds new challenges in achieving human water security and providing water for the environment.
- The ecological condition of aquatic ecosystems continues to decline while the pressures continue to grow.
The urgency for implementation of environmental flows is now greater than ever.
The Brisbane Declaration and Global Action Agenda on Environmental Flows (2018)
The 20th International Riversymposium and Environmental Flows Conference held in Brisbane in 2017 was an opportune time to revisit The Brisbane Declaration (2007) and revitalise the action plan. A six-month consultation process with colleagues and symposium delegates before, during and after the 2017 Riversymposium produced a renewed declaration and action agenda.
A paper describing the process was published on 2 July 2018 in Frontiers in Environmental Science as part of a Research Topic on “Implementing Environmental Flows: Lessons for Policy and Practice”. The paper hit 883 reads within a week of publication.
Here are some highlights:
- a revised definition:
“Environmental flows describe the quantity, timing, and quality of freshwater flows and levels necessary to sustain aquatic ecosystems which, in turn, support human cultures, economies, sustainable livelihoods, and well-being”
- inclusion of rivers, streams, springs, riparian, floodplain and other wetlands, lakes, coastal waterbodies, including lagoons and estuaries, and groundwater-dependent ecosystems in the scope of environmental flows
- an urgent call for action to protect and restore environmental flows and aquatic ecosystems for their biodiversity, intrinsic values and ecosystem services that sustain human societies and economies
- a foundation for achievement of the many water-related Sustainable Development Goals
- 35 actionable recommendations to fill research gaps and support implementation of environmental flows
- a new element – the full and equal participation for people of all cultures, and respect for their beliefs, values, knowledge, rights, responsibilities and systems of governance in environmental water decisions
- a plan for global dissemination and engagement in the environmental flows enterprise.
I hope ARI researchers will continue to develop this exciting field of water for the environment balanced against human needs and aspirations.
Vörösmarty et al. (2010). Global threats to human water security and river biodiversity. Nature 467: 555–561. doi.org/10.1038/nature09440
Arthington and Pusey (2003). Flow restoration and protection in Australian rivers. River Research and Applications 19: 377-395. https://doi.org/10.1002/rra.745
Arthington (2012), Environmental flows: Saving rivers in the third millennium. University of California Press, Berkeley. https://doi.org/10.1002/rra.2635
Horne et al. Eds (2017). Water for the Environment: From Policy and Science to Implementation and Management. Elsevier, Cambridge, MA.
King and Pienaar Eds (2011). Sustainable use of South Africa’s inland waters. Water Research Commission Report No. TT 491/11. Water Research Commission, Pretoria.
O’Donnell (2014). Common legal and policy factors in the emergence of environmental water managers. Water and Society II. UK. doi:10.2495/WS130271.
Harwood et al. (2017). Listen to the River: Lessons from a global review of environmental flow success stories. WWF, Woking, UK.
Winemiller et al. (2016). Balancing hydropower and biodiversity in the Amazon, Congo, and Mekong. Science 351(6269): 128–129. https://doi.org/10.1126/science.aac7082
Grill et al. (2015). An index-based framework for assessing patterns and trends in river fragmentation and flow regulation by global dams at multiple scales. Environmental Research Letters 10(1): 015001. https://doi.org/10.1088/1748-9326/10/1/015001
Arthington et al. (2018). The Brisbane Declaration and Global Action Agenda on Environmental Flows (2018). Frontiers in Environmental Science. https://doi.org/10.3389/fenvs.2018.00045