Expectations and Insights about Large River Floodplain Restorations: Floods, Invasive Species and Stakeholder Tradeoffs

The assessment of the 8yr old restoration of 2,700 ha of floodplain in the Illinois River (a former levee district, now the Emiquon Preserve) has largely focused on documenting the trajectory of restoration, evaluating effects of the record flood of 2013, as well as understanding biotic and habitat interactions. Before restoration, this former floodplain lake complex was disconnected from the Illinois River and underwent continuous agricultural production for nearly 80 years. Farming ceased and a variety of restoration actions began, most notably floodplain inundation and fish stocking, in 2007. Since that time the diversity, abundance and biomass of plankton, vegetation, invertebrates, fish (both forage and sportfish species) and waterfowl have increased steadily to the point where Emiquon is one the best examples of a floodplain backwater in the river valley. However, because not all actions or stressors are predictable, the impact of each on desired restoration outcomes has been tracked. Insights gained from this monitoring –importance of duration and magnitude of inundation, the role of  biotic interactions, patterns of species succession -  should help guide both the choice of future management actions such as reconnection, the effect of altered hydrology or invasive species at Emiquon and elsewhere around the nation.