Commonwealth Long-Term Intervention Monitoring Project: Stage 1 Mid-Term Review and Evaluation

5.2LTIM objectives

This Section covers the need to review the current expectation from the Basin-scale evaluations, assessment of the contribution of the CEW, and the updating (or setting) of objectives for multi-scale watering events and key ecosystem types.

5.2.1Expectations from the Basin-scale evaluation

The expectations for this Project were set in 2013-14. There has now been three years of Project implementation, during which time many issues (some quite unexpected) have emerged and solutions had to be found at both the Selected Area and Basin-scale. This is not unexpected given the scope and experimental nature of this LTIM Project.

However, the time taken to find solutions to these quite difficult issues has meant that some of the more long-term objectives have had less attention than was originally envisaged. Consequently, some of the initial expectations of the Basin-scale evaluation are unlikely to be met. These include: the Basin-scale quantitative models; and the inferring of the outcomes of CEW in areas not monitored as part of the LTIM Project.

We have recommended that the Basin-scale evaluation questions are reviewed for their relevance and feasibility, and modified if need to ensure the expectations of this Project can be adequately met by June 2019 (Recommendation 1). A review of how water quality is treated in the Basin-scale evaluation should be included in this process.

5.2.2Assessment of the contribution of Commonwealth environmental water

We note that many of the key evaluation questions being addressed at both the Area-scale and Basin-scale are focused on the contribution of the Commonwealth environmental water to key ecological outcomes such as fish breeding, wetland vegetation community diversity and ecosystem diversity.

We were told that this particular Commonwealth focus, while understandable, has caused some problems with the reporting of ecological outcomes as a result of environmental watering events where the Commonwealth’s contribution may be only part, and sometimes a quite small part, of the total environmental water delivered.

This difficulty has been largely addressed by the CEWO who have broadened the interpretation to focus on assessing the outcomes for all environmental water, and where possible assess the contribution of Commonwealth’s water, as documented below¹¹:

What does ‘with and without Commonwealth environmental water’ mean for evaluation purposes?

The issue of what ‘with/without CEW’ means for LTIM evaluation purposes has come up, and specifically what the contract means when it says that Providers must: ‘quantify to the fullest extent possible the marginal benefit of Commonwealth environmental water and other held environmental water delivered in conjunction with Commonwealth environmental water’ (Schedule 3, Clause 4).

The overarching purpose of the LTIM Project is to monitor and evaluate the contribution of Commonwealth environmental water to Basin Plan environmental objectives.  Nonetheless, the reality is that CEW is often only part of the picture, and delivered in conjunction with other held or planned environmental water or on the back of natural flows for example. 

The question of when Providers should try and separate the relative contribution of CEW to the overall outcome of a watering action with multiple water sources will invariably depend on what the management objective is.

In situations where multiple water sources are delivered, it may be appropriate to separate the relative contribution of CEW to the overall outcome.  A hypothetical example may include where CEW is being delivered following a State watering or natural event to extend the duration of wetland inundation in support of water bird breeding. The CEW component has a specific objective here that can be separated from the overall outcome – to extend the duration of inundation for a certain period of time/water level/recession rate etc so that the waterbirds can successfully finish their breeding activity. Understanding exactly what CEW is contributing to a hydrograph may also be important when mapping biotic samples to flows from upstream tributaries.

Conversely, it may be inappropriate to separate the relative contribution of CEW to the overall outcome of a watering action with multiple water sources. In those circumstances, CEW is only part of the picture, and we monitor and evaluate the effects of environmental watering as a whole - given that the action design (and thus expected outcomes or watering objective) would likely have been different, had the additional non-Commonwealth water not been available. An example may include where TLM, VEWH and CEW is being delivered in conjunction to achieve a fresh which a distinct hydrograph shape to trigger golden perch spawning. Under such circumstances, Providers should be looking to assess the outcome of the watering action as a whole - recognising as important context the multiple sources and volumes of water that contributed to it. 

5.2.3Improve the expected outcomes for large multiple-scale watering actions

The 2015-16 Synthesis Report (Gawne et al. 2017) noted that the CEWO is increasingly moving toward coordinated large-scale watering actions that influence multiple assets and rivers, and that it is important for the monitoring and evaluation process to be modified to ensure the adaptive management can be undertaken at this larger scale.

The delivery of environmental water to local assets is complex enough without the need to determine (and deliver) ecological outcomes at multiple scales. Currently, the communication of the expected outcomes from the multiple-scale watering actions is imperfect so that the full range of expected outcomes that have guided the multiple-scale environmental water delivery may not be clear to monitoring teams. This can reduce the effectiveness of evaluation and limit the ability of the LTIM Project teams to provide advice on adaptive management of environmental water. Accordingly, we have recommended that this issue be addressed (Recommendation 2).

5.2.4Expected outcomes for key ecosystem types (Ecosystem Diversity)

The 2015-16 Synthesis Report (Gawne et al. 2017) also noted that the increased focus on multi-scale watering actions has implications for the ecological scale of expected outcomes; that is there is a need to consider ecosystems in addition to species and populations.

It has been argued that there is a need to better understanding how key ecosystem types influence Basin biodiversity, resilience, ecosystem function and ecosystem services. Delivering Commonwealth environmental water for ecosystem objectives will require that the LTIM Project move beyond counting the ecosystem types watered or whether some types have had watering targets met. There will be a need, for example, to ‘shape’ flow regimes so that patterns of spatio-temporal variability along a river are preserved, or perhaps to deliver water at critical times to maintain life forms or ecosystem processes.

The CEWO currently does not have documented 1-year or 5-year expected outcomes for ecosystem diversity¹² and needs to develop these (Recommendation 3). CEWO delivery teams often plan to link ecosystem types to water availability scenarios, such as directing water to maintain permanent water systems in dry years, or augmenting overbank flows to the floodplain in wet years, but these actions rarely have explicit ecosystem outcomes.

5.2.5Recommendations

Recommendation 1: that the Basin-scale evaluation questions are reviewed to assess whether they are all still relevant, and the likelihood that they will be adequately addressed by June 2019. In light of this review to the CEWO should make any modifications that would update the expectations of the Basin-scale evaluations.

Recommendation 2: that for multiple-scale watering actions, CEWO ensure the full range of expected ecological outcomes are determined and communicated to the appropriate LTIM Project teams.

Recommendation 3: that the CEWO develop expected outcomes for the ecosystem diversity Basin Matter.