Historically, the flood plain of the Middle Mississippi River included natural wetland features such as backwater lakes, sloughs and secondary river channels. Many of these features have been modified or cut off from the river itself by dikes and levees. Refuge staff work closely with river managers to enhance and restore these wetland features wherever possible.
By allowing the river to re-connect with its flood plain, the annual cycle of wet and dry periods can be restored, along with the wildlife communities that depend upon them. Typically, the late spring and early summer periods see the highest river stages, and floodwaters find their way back into sloughs and small lakes. Native fish move into these areas to spawn, and migratory birds, "fuel up" during their migration to the northern breeding areas.
Wetland management in the active floodway of the Mississippi means allowing the river access to its historic flood plain. Most water control here is passive, not influenced by pumps or gates. In some areas, earthen berms and water control structures will be used to catch water in basins, allowing migratory birds and fish a longer period on the flood plain. Those areas will then be slowly drained back to the river, providing a nursery of sorts for native fish, and exposing mudflats for migrating shorebirds.