As you drive northbound outside the city, a sudden and dynamic change in the landscape occurs once you cross to the other side of the levee. Bounded by seemingly endless cement, floodgates and cypress forests, the Lake Pontchartrain Estuary makes up 10,000 square miles of Southeastern Louisiana and is the largest delta in North America.
These unique swamp ecosystems peppered throughout have the feel and appearance of a land before time. Immerse yourself in a delta-made cypress swamp, and you might envision dinosaurs and creatures long extinct rummaging the landscape, but in fact…this is some of the nation’s youngest acreage. Rewind the clock only 5,000 years and the greater New Orleans area would have been found beneath the shifting waters of the Gulf of Mexico. So how did Southeastern Louisiana just appear basically overnight from a geological standpoint? The answer lies at the bottom of North America’s largest river.
The Mississippi River drains 41% of the continental United States. Before industry and settlement along its banks created the need to control, levee and dam the fluctuating water shelf, the spring flooding from northern snow melts would dramatically widen the waters at its delta, sprawling and reaching out towards the gulf. The fast moving water upwelled and carried great amounts of sediment on its 2,350 mile trip and dumped is over this widened expanse, rapidly forming the land mass where modern day New Orleans now rests. The Lake is a product of this swelling delta forming to the south, eventually blockading the estuary on all of its borders.