Using river-scale experiments to inform variable releases from large dams: a case study of emergent adaptive management

Case studies of successful adaptive management generally focus on examples that have frameworks for adaptive management embedded from project conception. In contrast, this paper outlines an example of emergent adaptive management. We describe an approach whereby targeted research and collaboration among stakeholders assisted learning, and ultimately the development of interim operational guidelines for increased within-channel flow variability in the highly regulated Mitta Mitta River, which is managed as part of the River Murray System in the Murray–Darling Basin, Australia. Environmental monitoring of four variable flow trials evaluated the response of water column microbial activity, benthic and water column metabolism, the structure and composition of algal biofilms, and benthic macroinvertebrates to increased flow variability created by varying the release from Dartmouth Reservoir. Each trial built upon lessons from previous trials, with collaboration among key stakeholders occurring before, during and after each trial. Institutional conditions encouraged a shift to adaptive management over time that helped to achieve environmental, social and economic objectives downstream of the dam. A key lesson is that adaptive management does not have to be specified 'a priori', but can emerge within a trusting relationship between stakeholders as long as they are willing and able to change their operational paradigm.