Levees are decades-old protectors

Julie Cooper in the Natchez-Democrat (Mississippi) provides some history to the levees holding back the surging river: The history of the Mississippi River levee system as we know it really begins in 1927. Levees weren’t a new idea then, but creating a federally controlled system of them was. The Great Mississippi River Flood of 1927 killed 246 people and covered thousands of square miles with up to 30 feet of water.

Levees along the Mississippi and its tributaries have existed since the 1800s. But it wasn’t until the Flood Control Act of 1928 that they began to grow taller, stronger and were connected to form a mainline levee all along the river.

The U.S. Corps of Engineers Vicksburg District was unable to provide any exact dates for work done on the local levees, but said work to strengthen the levee system has continued as funding was appropriated since 1928.

In addition to the mainline Mississippi River levee that runs the length of the river in Concordia Parish and to the north and south of it, the parish is nearly totally ringed with another levee system. The ring levee, as local leaders call it, runs alongside the Red, Black and Tensas rivers.

…Local levees were built up from the originals constructed well before the Civil War, Robinson said. They are composed of dirt and clay. A hydrologic analysis is used to determine what the appropriate construction and height should be, he said.

“They go out and do geological borings to analyze and look at what the structure of the existing levee is,” Robinson said. The results of those studies direct the Corps to know what type of dirt is best for that particular section of levee…

The Great Mississippi Flood of 1927, dynamiting through the levee to create an artificial crevasse at Caernarvon, St. Bernard Parish, Louisiana, 14 miles below New Orleans. The crevasse was created to take pressure off levees at New Orleans