The primary purpose of this report is to provide an adaptive management approach for learning more about summer water level reductions (drawdowns) as a management tool, including where and how drawdowns can be applied most effectively within the Upper Mississippi River System. Our approach is not an attempt to achieve a specific management objective, but to generate new knowledge directly related to increasing managers’ ability to predict the effects of drawdowns. The report reviews previous drawdowns conducted within the system and provides specific recommendations for learning more about the lesser known effects of drawdowns and how the outcomes can be influenced by different implementation strategies and local conditions. The knowledge gained can be used by managers to determine how best to implement drawdowns in different parts of the UMRS to help achieve management goals. The information and recommendations for learning contained in the report are derived from results of previous drawdown projects, insights from regional disciplinary experts, and the experience of the authors in experimental design, modeling, and monitoring.
October 1, 2010