By Paige Brown
Once upon a time, the Mississippi River ran wild and uncontrolled from its source in Minnesota to the Gulf of Mexico. The river experienced massive shifts in its course half a dozen times over the last 10,000 years, gradually contributing upstream soil and sediments to what we know today as the Mississippi River Delta and coastal wetlands.
The Mississippi River was historically a meandering and dynamic river, providing resources for the growth of coastal wetlands in Louisiana. However, points out Clint Willson, LSU professor of civil and environmental engineering and director of the university’s Vincent A. Forte River and Coastal Hydraulics Lab, over the past 200 years or so, humans have significantly molded the course and history of the Mississippi River.
“The Mississippi River used to swing back and forth across the eastern half of the Louisiana coast,” Willson said, pointing to the historic river maps that line the walls of his office at LSU. “That is, until we settled along the river and wanted to start making it reliable and safe. What we built over time, for the good of the U.S., was a highly engineered massive river system lined with levees and other control structures.”
While systems of levees and dams have controlled the river and made it more safe and reliable for navigation and commerce, the highly engineered river system that we have today has important consequences for the sustainability of our coast. Through his work on physical and numerical modeling of water and sediment in the river and river delta, Willson understands the importance of river engineering and planning projects to the maintenance of our natural coastal system.
“The natural Mississippi River delta would still be growing parts of our coast today, if we hadn’t engineered the river to the point where we no longer have a natural delta,” Wilson said. “So what does all of this mean, and what do we do going forward to maintain our coast? What is a realistic vision for the future?”
Willson, an expert in Mississippi River hydraulics and sediment transfer, has been studying the path sediment takes – or could take – over the lower 84 miles of the Mississippi River for years. His team at the Vincent A. Forte River and Coastal Hydraulics Lab, with the support of the Louisiana Office of Coastal Protection and Restoration, has used a small-scale physical model of the river to study the potential for large-scale river and sediment diversions in coastal restoration. Using physical modeling tools, Willson’s team is trying to look into the future and develop realistic goals for maintaining and restoring natural deltaic processes and sediment deposition in key areas. In developing these goals, Willson works with LSU’s Coastal Sustainability Studio, or CSS, to take navigational, community, industrial and agricultural infrastructures into account. Willson and his research group have made significant progress toward figuring out better ways to utilize the Mississippi River and its resources to help sustain working coastal systems.
“Looking into the future, we have to consider how we will ensure safe, reliable and economically feasible infrastructures in coastal areas,” Willson said. “We have to consider many different pieces of the overall picture, such as flood control, navigation and coastal restoration. We have to consider how we can get people to think about how these different pieces fit together. This is where the Coastal Sustainability Studio comes in.”
For example, in creating visions for the future, Willson and his team, in collaboration with the Coastal Sustainability Studio, consider the regional impacts of various river design and management strategies, including impacts on communities, industries, navigation and wetlands.
“We have to match river hydraulics with the economic and community interests of the people living in these coastal areas,” Willson said. “We need to combine LSU’s expertise in the coastal, societal and geologic history of the coast and the Mississippi River with our engineering expertise, in order to improve designs and infrastructure for the river in the interest of coastal restoration.”
According to Willson, it is important to understand the ancient history of the Mississippi River and River Delta, as well as the more recent history of the river’s engineered landscape, to plan for the future of our coast. Willson sees the story of the Mississippi River as taking place in four main chapters: the first tells the story of an uncontrolled and dynamic river building the eastern half of the Louisiana coast; the second tells the story of humans engineering the river at the cost of natural coastal systems; the third tells the story of decades of very important research and the development of new models and tools for a better understanding of river management strategies. Willson envisions the fourth and latest chapter as a tale of people working together to plan for a sustainable coastal future.
“We are interested in river hydraulics and sediment transport,” Willson said. “But we are also interested in using these tools to look into the future to develop a positive vision for our coastal landscapes.”
Willson will be presenting at LSU’s next Science Café, to take place at Chelsea’s Café in Baton Rouge on Tuesday, March 26. Willson will discuss the mighty Mississippi River and how sediment flow through the waterway affects everything from industry and economics to the way people live along the river. He will introduce the university’s new river model, which will be a fully automated 1 foot to 1 mile replica of the river from Donaldsonville down to delta’s mouth. The event will kick off at 6 p.m. on Tuesday evening.
To read more about the new Mississippi River model, please visit http://theadvocate.com/home/4822326-125/bigger-better-model-of-mississippi.
For more information on LSU’s Science Café, please visit the event’s Facebook page at https://www.facebook.com/events/129840270531363/.