Michael Reuter is the director of The Nature Conservancy’s North America Freshwater Program and the Great Rivers Partnership.
We have witnessed one of the greatest floods in recorded history on portions of the Mississippi River. The numerical measurements reflect the sheer magnitude of this event ― 2.33 million cubic feet per second at Vicksburg, Mississippi; about 2.2 million acres of farmland under water; 106.6 feet above sea level at Vicksburg and 66.72 feet at Cairo, Illinois. But the impact on people’s lives is beyond measure.
While I have watched as floodwaters inundated the Birds Point New Madrid Floodway in Missouri and as water gushed through the openings at Bonnet Carre Spillway and Morganza Floodway in New Orleans, I have also witnessed the hope and strength of individuals and communities ― traits that have sustained the Mississippi basin and its people since before the Great Flood of 1927.
All of us at The Nature Conservancy extend our best wishes to everyone impacted by the flood. We, too, have deep roots in the Mississippi basin, with staff living and working from the headwaters to the Gulf of Mexico.
Floodplains: The Natural Solution
The successful management of the 2011 flood to date reflects an intergenerational investment in river engineering structures that began 83 years ago. Prior to the 1927 flood, our approach was to mostly manage these floods by building levees higher, but nature renegotiated that strategy by claiming more than 500 lives and displacing at least 700,000 people. So instead of working against the river with a “levees only” approach, we began working with the natural functions of the river.
Formed by natural processes, floodplains are designed to absorb floodwaters and nutrients, while sustaining a diversity of fish and wildlife. A natural part of the river channel, floodplains straddle our great rivers and function like time-share apartments, providing nutrients, shelter and spawning areas for river fishes at one time of the year, feeding areas to waterfowl and shorebirds at another time, and terrestrial habitat to wildlife like black bear at still another time.
Following the 1927 flood, the U.S. Army Corps of Engineers began purchasing easements along the river as part of the Mississippi River and Tributaries Project (MR&T). The easements were used to create “floodways” to help route high floodwaters through the system, taking advantage of the floodplain’s natural ability to convey and store floodwaters. Other key MR&T components include numerous interconnected channel design actions on the main stem of the Mississippi River and construction of secondary levees, flood control gates, pumps and reservoirs, and more. Click here and here to learn more about the MR&T Project.
The 2011 flood is the first time that three floodways have been operated simultaneously, successfully demonstrating the importance of connected, fully functioning floodplains as thousands of human lives and billions of dollars in infrastructure have been spared during this event.
But we must ask ourselves: Have we reserved enough floodplain to match the floods of the future?
Managing for the Future
Analysis of stream flow data for the United States during the past 50 years shows that floods are more frequent and more severe. When the MR&T Project was developed in the early 20th Century, the focus was on flood control and navigation. Today, we expect much more from our rivers and floodplains, as evidenced by the increased drainage from millions of acres of farmland in the basin, faster runoff from urban areas, and increasingly intense storms ― factors that have created a host of new problems.
So as we consider future flood management, we must also ask:
- How can these floodplains help remedy the pollution that leads to a dead zone at the mouth of the Mississippi?
- How can we address groundwater recharge at the same time? (Ironically, western Louisiana is suffering from a drought, while eastern Louisiana is experiencing epic flooding.)
- How do we convey sediment to rebuild coastal Louisiana, which is now losing the equivalent of a football field of valuable wetlands and storm buffers every hour?
A Shared Vision
In preparing a vision for 21st Century flood management, we must build on the features of the current system ― such as connected, fully functioning floodplains ― while correcting the problems. A comprehensive system for today will continue to use floodplains to keep people safe while benefiting fisheries, habitat and nutrient reduction for the Gulf.
The Nature Conservancy is committed to shaping a shared vision for the whole Mississippi River system, developed with and shared by the navigation industry, the flood control community, the agricultural industry, various social and environmental interests, and others. More than 80 organizations representing all these interests have been involved to date.
This collaborative approach is the spirit of our Great Rivers Partnership (GRP) – to engage diverse stakeholders and use sound science to achieve sustainable management of the Mississippi and other great rivers so they work for people and nature. The GRP engages at a broad level based on what we’re learning on the ground:
- agricultural watersheds where we work closely with farmers to develop and employ best practices for water and nutrient management;
- floodplain areas like Mollicy Farms in Louisiana and Emiquon in Illinois to demonstrate floodplain management for multiple benefits;
- and oyster reefs where we are restoring critical marine habitats.
We are also connecting our work globally to places like Colombia’s Magdalena River, which is at this same time experiencing a record flood that has killed more than 500 people and displaced 3 million others. In all these places, we are working to maintain a connected, functioning floodplain that can provide critical water storage and reduce broader risks to life and property during epic flood events.
Success, however, will require a long-term, intergenerational vision shared and implemented by all stakeholders in the basin, a vision that recognizes the priceless human benefits that stem from our great rivers when managed thoughtfully for multiple purposes.
(Image: By releasing water into the Atchafalaya floodplain, the Morganza Spillway helps prevent the rise of the Mississippi River in Baton Rouge and New Orleans, Louisiana. Image credit: David Y. Lee)