Is that the Mississippi River? It sure looks tiny!
You can find this Mississippi River Physical Model at the Louisiana State University Center for River Studies. The 10,000-square-foot model shows a smaller version of nearly 200 miles of one of the most important rivers in North America. The model looks tiny if you’re comparing it to the real Mississippi. For a model, though, it’s massive—about the size of two basketball courts put together.
People put data about the Mississippi River into a computer. They used that information to cut high-density foam panels into the river’s exact shape. Held up by 864 jacks, the model is strong enough for people to walk on. When visitors go upstairs to look down onto the model, they can feel the moisture coming from roughly 6,000 gallons of water. Tiny particles of plastic in the water act like the sediment that courses through the real Mississippi River. And scientists can raise the water level in the model. That shows how rising ocean levels change what happens to the land around the river.
The model would probably make the ultimate action figure battleground or doll playground. But scientists use it for something else: fixing a big water problem in the United States.
The Problem
What’s the problem? You could express it like this: Hey, Louisiana. Looks like you’ve lost a few pounds . . . or maybe tons. And it’s not a good thing!
In Louisiana, wetlands are washing away—a lot of them. Altogether, the lost wetlands are the size of Delaware! Once, the Mississippi River fed those wetlands. The mighty river’s waters flowed there. And the Mississippi brought more than water. It carried nutrients and sediment too. But to keep their homes safe from flooding, people walled the river off. They harnessed the river’s power—and kept it in check—by building strong levees. (Levees are banks that direct a river’s flow.) Because they could control the river, towns along the water used its power to grow. They could also navigate the river reliably. That meant they could travel a huge distance through 10 American states.
People loved being protected from floods. But the wetlands didn’t love the levees. The Mississippi River was designed to overflow its banks and carry sediment to wetlands. The Mississippi’s overflow added sediment to keep the land from washing away, even when ocean levels rose. With no Mississippi flood sediment to build it up, the land gradually sinks below the water!
The Solution?
Rivers like the Mississippi don’t just want to flow in a powerful, human-controlled course. They want to meander . . . all the way down to the coast, where they create marshy land. Now people want to put the river back to work. They think, “All right, Mississippi, do what you used to do!” But how can they make that happen? Here’s their idea: slice through the levees so smaller streams of water can flow out again. Let them carry sediment back to the coast, rebuilding the land.
But that could come at a cost. People have grown used to the control the levees provide. The banks protect their homes from flooding. They allow businesses to prosper on the river’s banks. So scientists use the model to find out exactly how changing the levees will impact the river. And using the model, they can find out fast. After watching the model for just an hour, they can tell how water will move sand down the river for a whole year!
