Experts say a new approach is needed to save Australia’s non-perennial rivers. 

Non-perennial rivers, which stop flowing at some point each year, dominate surface water movement across Australia, yet monitoring the continued health of these vital waterways is challenging.

More than 70 per cent of Australia’s rivers are non-perennial due to a combination of ancient landscape, dry climates, highly variable rainfall regimes, and human interventions that have altered riverine environments.

Flinders University experts have completed an extensive review of current research - incorporating geomorphology, hydrology, biogeochemistry, ecology and Indigenous knowledge - which identifies prevailing factors that shape water and energy flows in Australia’s non-perennial rivers.

However, the review also points to research deficiencies that must be addressed if these river systems are to be preserved and protected.

While dominant research themes in Australia focus on drought, floods, salinity, dryland ecology and water management, the researchers say four other areas of research attention are urgently needed, specifically:

  • Integrating Indigenous and western scientific knowledge

  • Quantifying climate change impacts on hydrological and biological function

  • Clarifying the meaning and measurement of “restoration” of non-perennial systems

  • Understanding the role of groundwater

“Australia is globally unique in its spread and diversity of non-perennial rivers spanning climates and landforms – but most, if not all, of the classes of non-perennial rivers found in Australia also occur in other regions of the world with similar climates and geology,” says Dr Margaret Shanafield from Flinders University.

“Therefore, the evolving body of knowledge about Australian rivers provides a foundation for comparison with other dryland areas globally where recognition of the importance of non-perennial rivers is expanding.”

The review authors are concerned that Australian non-perennial river research has been driven by the needs of its inhabitants for survival, agriculture, resource economics, environmental concern and politics.

“Considering the continent's ancient geological history and its harsh, arid climate, it comes as no surprise that significant attention has been directed toward water resource management during drought periods, the reduction of salinisation, and gaining insights into the intricate dynamics of the transient rivers that are a defining feature of central Australia,” says the review.

“The prevalence of prolonged drought periods has had a marked impact on driving research – so it is critical to address the knowledge gaps this review has identified, given that increasing trends in hydrological droughts are projected to negatively impact streamflow not just in Australia, but also in South America, southern Africa, and the Mediterranean.”

The review authors say more investment in long-term hydrological monitoring is desperately needed to increase water management knowledge that can address the competing water needs of communities, agriculture, mining and ecosystems.