Making the Connection from Monitoring and Evaluation to Adjustment in the Glen Canyon Dam Adaptive Management Program

Making the Connection from Monitoring and Evaluation to Adjustment in the Glen Canyon Dam Adaptive Management Program

The typical portrayal of the six-step adaptive management cycle belies the complexity of getting from assessment to adjustment. Moving from monitoring and evaluation to major policy consideration and decision making, for example, can be very difficult, particularly when learning outcomes conflict with persistent stakeholder values, adjustments are much more costly to some participants than others, and they may become permanent rather than experimental.

The Glen Canyon Dam Adaptive Management Program has utilized active adaptive management, with the dam as the principal experimental tool to address strategic science questions developed cooperatively by scientists and managers. Large-scale experiments, coupled with extensive monitoring, modeling and analysis, have greatly improved the understanding of relationships between dam operations and resource responses. For example, the sediment-limited river can be forced to give up some of its stored sand for deposition on beaches using controlled floods, but the ensuing flows make this but a temporary fix. Controlled floods released in spring also cause a compensatory response in tailwater trout reproductive success, which may lead to density-dependent downstream migration and added predation pressure on endangered fish. Thus, another conflict, previous unrealized, is uncovered that further complicates the balance of dam operations and resource conservation.

Over the course of the adaptive management program, adjustments to dam operations have continued as experiments for defined periods following required environmental compliance, but there has not as yet been a comprehensive evaluation to follow the 1995 environmental impact statement that led to formation of the program. In the interim, learning has led to actions that expand beyond dam operations, such as non-native fish control and translocations of endangered fish to unoccupied tributaries. As learning has improved, managers have been challenged with developing mechanisms for incorporation of scientific results into decision making. Two episodes of structured decision making have occurred and the process shows promise in facilitating participatory environmental compliance and bridging the gap between scientific results and value-driven positions. The next major test for the program and the adaptive management process is soon forthcoming as the participants engage in the development of a new environmental impact statement that sets the stage for consideration of major policies.