The river systems of the Lake Eyre Basin are still in good health. The Lake Eyre Basin Intergovernmental Agreement aims to assist in maintaining that status.
The Agreement has led to two activities in ongoing assessment of the health of the Basin.
- Every 10 years a review is conducted of the condition of the Basin’s watercourses and catchments. The reviews are a requirement of the Agreement. The most recent review is the Lake Eyre Basin: State of the Basin Condition Assessment Report 2016.
- Ongoing monitoring and evaluation of river systems and biodiversity in the Basin. The Lake Eyre Basin Rivers Assessment program (archive version), conducted collaboratively by scientists from the Northern Territory, South Australia and Queensland, was the first cross-border monitoring effort. On this foundation, a comprehensive monitoring and evaluation program is now being created.
State of the Basin 2008: Rivers Assessment Report
The State of the Basin 2008: Rivers Assessment Report (archive version) was a desktop analysis of information from government agencies, natural resource management bodies and researchers. It found that Basin rivers and catchments are in generally good condition. Lack of modification of river flows means that aquatic ecosystems are relatively intact.
At the time, Cooper Creek was the most studied catchment of the Basin’s five main catchments. The 2008 Report recommended that future river assessments:
- Develop better understanding of water flows and boom-and-bust cycles.
- Continue reviewing threats to the condition of rivers and catchments.
- Focus on inappropriate water resource development, invasive pests and land-use intensification.
State of the Basin Condition Assessment Report 2016
The Lake Eyre Basin: State of the Basin Condition Assessment Report 2016 (archive version) is the most recent review. It brought together knowledge of water flows, water quality, fish and waterbirds of the Basin and identified threats to these features. It reached the following conclusions.
- River systems and biodiversity of the Lake Eyre Basin are in relatively good condition. In contrast to the neighboring Murray–Darling Basin, water flows and landscapes of the Lake Eyre Basin are little altered. The Basin continues to support diverse ecosystems and rich populations of fish and waterbirds.
- River systems of the Basin experience highly variable flows. At any location the condition of a river system fluctuates according to flooding, so a waterhole might appear healthier or less healthy depending on the period since the last fresh pulse of water. Even so, records so far show no sign of long-term changes in water flows or water quality in the Basin.
- Scientists from the Northern Territory, South Australia and Queensland collaborated on the Lake Eyre Basin Rivers Assessment program (archive version), which monitored 19 native species of fish over several years. The scientists concluded that fish populations are in good condition. Nevertheless, invasive fish are more widespread in waterholes and mound springs than previously thought. The translocated sleepy cod in the Cooper Creek is of concern because of its potential effects on the Ramsar-listed Coongie Lakes.
- Waterbirds are stable in abundance and diversity, based on thirty years of monitoring. They vary in abundance according to flooding and drying, of course, but the fluctuations seem mostly to be natural.
- Threats to water resources and river systems are low and mostly localised near waterholes.
- Invasive plants and animals are the greatest risk.
- Climate change is an emerging threat, with the potential for effects on water resources, river systems and biodiversity. Predicting impacts of climate change is difficult because rainfall and river flows are so unusually variable.
The Condition Assessment Report 2016 identified priorities to conserve river systems and biodiversity:
- Containment of invasive species.
- Maintaining low levels of water extraction.
- Planning of development to allow natural patterns of inundation on floodplains.
- Education and enforcement to limit overfishing and illegal fish stocking in waterholes.
- Limiting 4WD damage, stock access, firewood harvest and invasive plants around waterholes.
If you need more information, contact lebsecretariat@awe.gov.au