Investigating low flows for improved water planning and management
| Objective: | To better incorporate low flow considerations in water planning and management across Australia by identifying and implementing ways to improve low flows monitoring and modelling to achieve environmental objectives and also improve the low flow-relevant ecological information available to water managers. |
| Funding: |
up to $1.13 million (initial funding of $700 000 plus additional funding of $430 000) |
| Jurisdiction: | National |
| Commenced: | July 2009 |
| Project status: | Finalised |
| Outputs: |
Project details
Much of our knowledge of surface water hydrology and its dependent ecology has been derived from medium and high flow regime data associated with human concerns such as yield, reliability and flood frequency/ magnitude. Low flow regimes and related ecosystems have not been subject to a similar level of investigation. However improving our understanding of the hydrology and ecology of low flows is becoming more critical due to increasing demands on water resources, decreasing inflows in many parts of the country, and the increasing level of knowledge needed for sustainable water management. The Commission's Water Dependent Ecosystem position statement identified low flows as a high priority for future investment.
There were four planned stages for the Low Flows project:
Stage 1: Preparation of Scoping Papers to identify ways to improve-
- the monitoring and modelling of low flows to achieve environmental objectives
- the low flow-relevant ecological information available to and adopted by water managers.
Stage 2: Progression of draft proposals and selection of projects for investment based on advice from an Advisory Group of jurisdictional water planners/managers and commonwealth water agencies, as well as on Raising National Water Standards investment criteria.
Stage 3: Implementation of projects with jurisdictional collaboration if possible. This is expected to commence in August 2010 and continue through to December 2011.
Stage 4: Further knowledge adoption activities and evaluation of projects. This is expected to commence in December 2011 and continue through to June 2012.
Project outcomes
The 'low flows' project commenced in 2010 as a result of increasing realisation that this component of the flow hydrograph needed more attention in water planning and management - NWC Biennial Assessments of Progress in Water Reform found room for improvement in drought planning, defining how systems will operate during low inflows, considering climate change in water plans, and in handling ecological issues on par with hydrological issues. A review and prioritisation of knowledge gaps in monitoring and modelling low flows, and in the low flow-relevant ecological information, resulted in two low flows projects:
- The 'Low Flow Ecological Response and Recovery' project, led by Griffith University and Yorb Ltd, aimed to assist water planning by developing a contemporary, Australia wide understanding and quantification of the response to the onset of, and recovery from, single and successive low flow events by individual species, biotic assemblages and ecosystem processes. Identifying 'thresholds of potential concern' was a specific objective but clear thresholds were not present in datasets available. Project outputs include:
- a low-flow classification of streams and rivers across Australia
- identification of six ecologically-relevant hydrological indicators of low flow useful across much of Australia
- eleven case studies across Australia analysing hydro-ecological relationships for low flows that produced seven key findings regarding ecological responses to low flows
- a suite of hydrological and ecological indicators to function as early warning, diagnostic or compliance indicators for the onset of, and recovery from, low flow situations
- identification of low flow appropriate monitoring methods (ecological and hydrological) for different low flow regions
- four general low flow principles and associated management considerations
- The 'Low Flow Hydrological Modelling' project, led by Barma Water Resources, aimed to improve the accuracy and ease of modelling low flows and cease to flow circumstances in regulated, and gauged and ungauged unregulated, rivers across Australia, and thereby improve the information used to underpin water plans across Australia. Project outputs include:
- a stocktake and review of current models and modelling practices relevant to low flows
- four case studies trialling improvements to low flow modelling
- guidelines on model data requirements, model selection, model calibration (processes and performance) and transposition methods.
Both projects have involved direct input from jurisdictional aquatic ecologists, hydrologists and water planners in both technical and project oversight roles. The project could not have been completed without these enthusiastic and productive partnerships.
In summary the low flows project has:
- collated and solidified existing ecological response and hydrologic modelling knowledge related to low flows
- produced new low flow knowledge to assist water resource management
- made recommendations to improve modelling and monitoring of low flows
- provided assistance to transfer information from one place to another
- organised information into a format accessible to water planners and managers
The project has also:
- brought ecologists, modellers and planners together
- promoted productive exchanges of knowledge across jurisdictions
- benefited from strong collaboration and input by jurisdictions
- increased the capacity of people working in the low flows area
- facilitated professional networks amongst people involved in the project