The Cooperative Research Centre for Freshwater Ecology (CRCFE) was appointed to review the framework that the Queensland Department of Natural Resources (QDNR) has developed for identifying relationships between various indicators of river health and various hydrological measures. These are the main conclusions and recommendations of the review. (i) Technical Advisory Panels -The existing models of Technical Advisory Panel (TAP) membership and roles should be maintained, with due reference to the specific skills needed. -It may be perceived that there is a conflict of interest when TAP members are engaged as consultants to the TAP. Often, TAP members are clearly the most appropriate consultants for the work because of their expertise (which is why they have been chosen for the TAP). However, because the TAP's role is to provide advice to the Water Allocation Management Plan (WAMP), rather than to formulate the WAMP, it is unlikely that there can be a conflict of interest. -A conflict of interest may occur if QDNR staff, who may be involved with development of the WAMP, are also members of the TAP (though none have been to date). In this situation there may not be an independent review of that TAP member's work by the Department. (ii) Choice of key hydrological indicators -The existing flow regime must be accurately quantified using an Integrated Quantity- uality Model (IQQM), to provide a sound basis for investigating relationships between the flow regime and ecological conditions and impacts. The case of 'full utilisation of existing entitlements' is generally not an appropriate surrogate for the current flow regime. -A basic comprehensive statewide set of flow statistics should be developed and the most relevant and applicable of them should be chosen as hydrological indicators for each river across the state. This set of flow statistics should encompass the core water requirements of the full range of components of the ecosystem, including riparian, wetland and end-of system requirements. As well as this core set of flow statistics, others may be required on a basin by basin basis as indicated by hydraulic information for that basin (or parts thereof) or to cover special cases such as a particular in-channel feature or wetland. -The ecological relevance of each of the chosen flow statistics should be clearly stated. -Flow statistics should be interpreted in the context of the flow regime, and temporal sequencing should be taken into account. (iii) Choice of ecological condition indicators -The criteria for selecting reference sites should ensure the setting of ecologically relevant targets. -The current assessment criteria provide a useful guide to selecting reference sites. Further development of the selection criteria could be undertaken, giving consideration to defining 'reference condition' in terms of best management practice. Best management practice should include all aspects of land and water use, because it represents the target to be achieved. (iv) Benchmarking method -The Review supports the use of the benchmarking method. -The best available benchmarks should be used. The Review recognises that it is necessary to use benchmarks from outside the basin of interest when there are no suitable sites within the basin. Limitations associated with the chosen benchmarks should be acknowledged. -River health-flow relationships should be investigated with various univariate and multivariate analyses, as a research priority. The analyses can involve the use of non-standard statistical techniques and input from a specialist statistician. These relationships will provide an empirical model for assessing the ecological implications of altering the flow regime. -If statewide river health-flow models are to be developed, it is recommended that the relationships correlate observable biological and physical indices directly with modelled indicator data sets for a range of flow statistics and sites across Queensland and northern New South Wales. -The overall structure of the 'adaptive assessment approach' (which takes an adaptive management approach by setting hypotheses, testing them as part of the management cycle and then using these outcomes to improve management), provides a sound basis for water resource management. However, the use of ecological assessment curves is not recommended, for the reasons outlined below (see vii). -The Review endorses the QDNR's modified approach to environmental flow assessment (Appendix A). The method provides an efficient framework for determining ecosystem requirements for water, and the likely ecological consequences of water development. -To refine the benchmarking method the Review recommends that a set of criteria for benchmarking be developed, based on comparison of sites firstly within a basin and then in other basins, where the sites have the following characteristics: -similar geomorphology; -similar flow regime type; -same or close biogeographic region; -same relative position in catchment; -as similar as possible land use and presence of alien or introduced biota; taking account of the time since any upstream dam or weir was built. (v) Process-response models -Process-response models are useful tools for generating research questions and for community education. In the absence of suitable empirical data they provide a basis for setting interim flow options. -Process-Response models may also be used to integrate empirical information, when it is available. If environmental flow process-response models are sufficiently understood and empirical data have been incorporated, they may be used as predictive tools. (vi) Traffic light diagrams -The Review supports the use of traffic light diagrams. They provide an easily interpreted display of the outputs of benchmarking analysis, but the data on which they are based should be made available. (vii) Ecological assessment curves -If ecological assessment curves are used, the TAP should indicate what literature, site data and theoretical knowledge were used to generate the estimates of ecological merit, and what the curves actually represent. It should be made clear that the curves do not represent empirical relationships in cases when empirical relationships do not exist -The Review does not support the use of ecological assessment curves for the presentation of benchmarking analysis because: -they are confusing and complicated to interpret; -assumptions in their development are not obvious; -they are susceptible to misuse or misinterpretation; -they appear to present qualitative data and professional opinion in a overly precise and quantitative way; -an ecological merit score does not add value to the raw flow statistic; -the shading around the ecological assessment curve has no formal basis, and this should be stated clearly. It is highly probable that the uncertainty associated with such a curve would be considerably greater than Â±5%.
MDFRC funding agency: QLD Department of Natural Resources (now QLD Department of Environment and Resource Management)
MDFRC client: QLD Department of Natural Resources (now QLD Department of Environment and Resource Management)
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Copyright (2000) Murray-Darling Freshwater Research Centre.