Navigation, Flood Risk Management, and Mississippi River Ecosystem Rehabilitation

The Mississippi River is one of the world's great rivers and is the only river in the United States to be formally recognized by Congress as both a nationally significant ecosystem and commercial navigation system. The river has a long and colorful history and has played a significant role in shaping the region's social and economic development. However, the Mississippi River is not a single homogeneous unit. From its source in northern Minnesota to the Gulf of Mexico one can identify at least five distinct Mississippi Rivers based on geomorphology and hydraulics. Concomitant with these differences in the river are variations in navigation and flood risk management that result in divergent river management strategies. Levees, reservoirs, floodways, pools and locks are some of the different structures that are in place on various reaches of the river to address the concerns of flood risk management and navigation. The effects of river regulation, floodplain development and watershed modifications present constant challenges to ecosystem rehabilitation along the Mississippi River. Consequently, floodplain and wetland restoration must be developed within the context of the potentially different directions that navigation and flood management have taken the river. Because the Mississippi system varies widely in hydraulics and hydrology from source to the Gulf, ecosystem rehabilitation likewise takes different forms in different regions along the river. Moreover, the goals, targets and metrics of river rehabilitation are not constant across the entire river system.