Rivers, estuaries and wetlands
Australia’s inland waters – our rivers and floodplains, groundwater aquifers and springs, wetlands and saltmarshes, lakes and estuaries support globally significant biodiversity, and are the lifeblood of agriculture, industry and communities.
Australia as a nation could not exist without taking water out of the natural environment and using it for domestic and productive purposes. Our challenge is to put water use on a sustainable footing, which means securing environmental flows and supporting ecosystems. With climate change underway, we also need to plan for a future with more extreme conditions and altered water availability across many regions.
Much is at stake, including:
- essential ecosystem services we derive from healthy inland water systems, such as the oxygenation of water, cycling of nutrients, balancing of salt and filtering pollutants
- biodiversity maintenance
- food security
- economic and social benefits from use of water in industry and recreation.
The presence and absence of water are critical in Australian ecosystems. Seasonal changes in water flow and large variations in flow between years – Australia’s famed ‘boom and bust’ water patterns – drive the lifecycles of many of Australia’s freshwater-dependent organisms and ecological processes.
Plant and animal numbers fall as habitat is destroyed by water extraction, land clearing, industrial and agricultural development and urbanisation. Between 1983 and 2010 there was a consistent recorded reduction in wetlands across Australia, accompanied by a drop in the number of waterbirds.
Diversion for human use
Humans have diverted natural flows, taken water out and built dams and levees. While most inland water systems in northern Australia and Tasmania have unimpeded flows, in the rest of Australia it is a different picture. About 70% of the water in the Murray-Darling Basin is taken out for human use, mostly for irrigation. Unsustainable extraction of groundwater continues in many areas, and demand for and pressures on groundwater are increasing.
Pristine northern Australian waterways
It is important to note that northern Australia, where the extremes of wet and dry are pronounced, contains the highest concentration of free-flowing rivers in the world, which are generally in good condition. The ecological systems of the region’s floodplains, wetlands and rivers remain relatively pristine, by national and global standards, and capable of supporting rich biodiversity and traditional Indigenous livelihoods.
Wastewater and farm runoff including fertilisers and manure add nutrients to inland aquatic ecosystems. This leads to algal blooms and the spread of invasive plants.
Erosion caused by land clearing causes increased sediment in inland waters which can kill fish and aquatic invertebrates and limit light penetration, stopping aquatic plant growth.
Other pollutants such as oils, detergents and rubbish enter our waterways via urban stormwater drains, while heavy metals from mining and industry are carried by washed-away sediment.
Invasive plants and animals are a major threat, competing against native species for habitat and food. Carp comprise 58% of total fish biomass in all rivers nationally, and cane toads and feral pigs cause widespread damage in northern Australia.
Climate change is the main overarching threat, with risks likely to come from changed flows, changed flood timing and frequency, and saltwater intrusion to coastal floodplains and wetlands.
We need to dramatically change the way we relate to inland water – Australia’s lifeblood. While this list is not comprehensive it will give you an idea of the solutions required to protect our precious inland waters.
Increase the protection of our rivers, important wetlands and other inland waters by:
- protecting our remaining unspoiled rivers
- restoring environmental flows
- avoiding detrimental future development of Australia’s tropical rivers
- helping identify the environmental needs to maintain river health
- defining and identifying iconic wetlands and restoring flows to them at a regional, state and national level
- fencing off waterways and water bodies from livestock.
Improve the ecological management and planning of our inland waters by:
- understanding the resource by developing an integrated surface and groundwater assessment program
- establishing comprehensive water accounts for each river valley and groundwater system
- developing rigorous regional water plans that are comprehensive and transparent
- clarifying water property rights.
- bringing over-allocated rivers and groundwater systems back into balance
- augmenting existing environmental flows by buying water and giving water saved from inefficient irrigation back to rivers
- defining, identifying and auditing important floodplains, headwaters, tributaries and catchment areas and removing earthworks that impede or capture environmental flows
- undertaking environmental and economic assessments for any new proposals that impact on inland water and factoring in the long-term ecological costs of water development proposals (such as dams)
- reducing the impacts of human populations so rivers around the world are also protected
- managing invasive species to reduce their negative impacts on native species and communities
- encouraging Indigenous water management.
Education and research
Further research and education on ecological management and planning of our inland waters by:
investing in science to support better decisions
- investing in social science research and activities that encourage acceptable outcomes in water reform
- bringing scientists together to synthesise their knowledge and packaging that knowledge for delivery to particular audiences
- building capacity across government agencies, technical specialists, academics and civil society to deal with the serious skill shortage in the water reform world
- building constituencies who can advocate for ecological outcomes.
Looking for more information?
Read about another issue: