The approach we have used has expanded our understanding of individual species at specific locations, and at specific times, into a holistic assessment of the ecological response of the Basin to environmental watering. This work has provided the necessary building blocks to create a Basin-wide model of ecological response that is a powerful tool in quantifying the overall benefit of Commonwealth water for the environment in the Basin.
One of the primary ways in which modelling has assisted the evaluation of Commonwealth water for the environment outcomes is by quantifying those outcomes. We already have models of hydrology (water movement), weather and other physical processes for the Basin. These models enable managers to understand the current physical condition of the Basin and, importantly, enable them to compare that to the condition that would be expected in the absence of water for the environment (the so-called ‘counterfactual’).
While models of many of the physical conditions in the Basin are well developed, there is no single model of ecological response at the Basin scale. Moreover, the effect of environmental water on ecological response depends on a range of environmental factors, in addition to the volume of water, and so can differ at different locations and times. This makes it extremely difficult for managers to create a holistic assessment of the change in ecological condition resulting from the use of water for the environment.
This means that the benefits of Commonwealth water for the environment cannot currently be objectively quantified at the scales of many of the management decisions. Our work created an architecture for a Basin-wide ecological model that moves us closer to being able to understand the ‘ecological counterfactual’ for the Basin. This gives managers a framework for quantifying the consequences of Commonwealth water for the environment.