While the overall concept of returning water to river ecosystems in the Murray-Darling Basin has been accepted, in practice there are many questions about how to deliver environmental water effectively at specific sites for demonstrable environmental benefits. In 2013, following Commonwealth buy-backs, the limiting factor is no longer the water itself, but the number of flow-ready sites where environmental planning, landholder agreements and administrative arrangements are in place so water can be delivered at appropriate times for environmental benefit. Another key factor is natural variability of flows, and the short lead time to predict seasonal conditions and select appropriate water regimes for each site.
Recent environmental waterings near Loxton in the SA River Murray Valley required targets with hypothesised benefits for each site, and monitoring of ecological responses. The specific environmental objectives and targets for a range of flow scenarios will be described, as well as the practical constraints on delivery, adaptive conclusions from monitoring of ecological responses, and constraints due to administrative requirements. The delivery of environmental water is a major experiment in adaptive management at a landscape scale. It is critical that learnings are shared and updated among practitioners and researchers to achieve most effective results in a highly sensitive political environment. The process needs to include feedback loops for adaptation in administrative processes, as well as in management, in order to achieve best possible use of available environmental water.