Hydro-ecological relationships - flow management and river rest
Project details
| Objective: |
To study hydro-ecological relationships of selected unregulated rivers of coastal and inland Queensland and New South Wales. |
| Funding: |
Up to $1,350,000 plus applicable GST from the Australian Government towards cost associated with supporting the work program. Total value of the project is up to $1,350,000. |
| Jurisdiction: |
Multi state |
| Commenced: |
May 2008 |
| Project status: |
Finalised |
| Outputs: |
About the project
Griffith University, through the International Water Centre, is commissioned to do the study. The project has the following components:
- develop knowledge on hydro-ecological relationships
- assess hydrological changes
- conduct a field research program to identify ecological outcomes of changes in flow regimes
- identify the effects of changes to flows in comparison with other pressures
- develop management guidelines that will help restore rivers by better managing the effects of changes to flows and other pressures, such as land use change and weeds.
One river will be selected from each of the following regions: Wet Tropics; Dry Tropics; Central Coast Queensland; south-east Queensland; northern New South Wales Coastal; Upper Darling/Lake Eyre Basin. Rivers of contrasting flow regime type and range/degree of hydrological alteration will be chosen based on available data and information.
Project outcomes
The Ecological limits of hydrologic alteration:a test of the ELOHA framework in south-east Queensland Waterlines report was launched at the Commission’s Highs and lows of river and wetlands health seminar held in Canberra on Thursday 22 March 2012.
The research was undertaken by the Griffith University in collaboration with the International WaterCentre and delivers the following products to assist wetland managers, water planners and policy makers in making decisions on flow regimes that promote ecosystem health. It will also provide valuable knowledge for anyone wishing to implement the ELOHA framework:
- Waterlines report: The Ecological limits of hydrologic alternation: a test of the ELOHA framework in south-east Queensland (AH Arthington, CS James, SJ Mackay, R Rolls, D Sternberg, A Barnes, S Capon) report presents a summary of key findings, key messages, recommendations and science from the project work.
- Science report: The Hydro-ecological relationships and thresholds to inform environmental flow management (AH Arthington, CS James, SJ Mackay, R Rolls, D Sternberg, A Barnes) report is published by the International WaterCentre and is available on their website: http://www.watercentre.org/ This report details the scientific aspects of the project in detail including the geographic area, field study design, results for each biotic component and three literature reviews that contributed to hypothesis generation for each ecologic asset explored.
Coomera River south-east Qld
Photo: D Sternberg
This four-year project is the first study in Australia to explore the scientific and management implications of the ELOHA framework – an internationally recognised model for regional environmental flow assessment. The project provides a hydrologic classification for rivers of south-east Queensland and through additional analyses, gives new ecological response knowledge relevant to the management of flow regimes and river eco-systems.
Critical to the success of this project has been the collection and analysis of field data to inform the research results and the scientific rigor the research team has applied in designing and undertaking the work.
Sampling riparian vegetation Photo: C James
The project team determined that every dam in south-east Queensland alters downstream flow regimes in a different way. The research has quantified that fish are most affected by zero and low discharge and high discharge which influence fish habitat and could allow alien species who are less sensitive to these issues, to flourish. Flow variability during the dry season was the main influence on riparian vegetation as it relies on stream discharge when bank soils are less moist. The mobilisation of stream substrate was the most significant flow factor for aquatic vegetation as regular removal of these plants prevents excessive build-up of dominant species. Additionally, the team found that in the study region, whilst the alteration of flow was widespread, the degree of change is relatively minor and they confirmed the influence of other factors such as climate and land-use on ecological response to flow change.
The key messages arising from this work for south-east Queensland are:
- Management and monitoring of flow regimes and river ecosystems should take into account regional hydrologic variation. The hydrologic classifications developed can assist this process.
- Management and monitoring of flow regimes should take landscape and climatic factors into account.
- Local habitat characteristics are important factors and should be taken into account for management and monitoring of flow regimes.
- Hydrologic alteration needs to be maintained at low levels to maintain healthy aquatic ecosystems.
- Flow regimes in the study region should be managed with emphasis on the characteristics identified as most influencing the health of aquatic and riparian vegetation and fish.
- Different management approaches are required for each dam.
- Hydrologic alteration should be considered a probably current and future risk to river ecosystem health.
- Priority for revision of environmental flow arrangements should be given to dams that have stronger impacts on flow regimes and therefore have ecological impact.
- Further analyses of the ecological datasets produced by the project will yield greater knowledge of ecological response to flow alteration.