The Mighty Mississippi River
Feb 23, 2020
EDITION 1 | 2:30 read time
THE MISSISSIPPI DRAINAGE BASIN...
Spanning 31 US states & two Canadian provinces
The Mississippi Alluvial Valley, aka North America’s Amazon, generates significant value to the national economy despite the fact that over the last 100 years it has been depleted, altered and degraded. The southernmost region of the river basin is the Mississippi Alluvial Valley, the most ecologically degraded region in North America - originally 24 million acres of forest, now only 5 million acres of forest remain.
We moved to New Orleans during March 2017. My wife grew up here, so we adapted quickly (well, except for the stifling heat and humidity... lol) One of the first things I did was to purchase a fishing license. The state offers fresh water and/or a saltwater licenses. My go-to person for anything fishing related, was my father-in-law, a retired geophysicist, who worked and enthusiastically fished the local bayous and estuaries for many years. He navigated them like the back of his hand… When asked the question about fresh vs. saltwater, he promptly replied: “Get both.” When I questioned why, his answer was simple: “because the salinity in the water changes constantly, this month you're fishing salt, next month fresh.” His answer was probably an exaggeration, but this comment pique my interest. Another question I had was why is Maurepas, Pontchartrain and Borgne are called “lakes” and not lagoons? Usually, lakes are fed by freshwater rivers and streams, and not a body of water that constantly flows into the ocean, in this case the Gulf of Mexico. “It just is…” was my father-in-law’s reply. Lakes vs. lagoons aside, the challenge here is much bigger:
Wetland & Coastal land loss in Louisiana and the role levels of salinity plays
The statistics on wetland and coastal land loss in Louisiana are staggering — the state loses roughly one football field of land every hour. Scientists say Louisiana’s land loss can be attributed to at least three critical factors: 1) reduced sediment flow from the Mississippi River and its tributaries, 2) subsidence, and 3) sea-level rise. These factors can result from natural processes, human interference, and in most cases, a combination of both. Communities are changing, wildlife are losing their habitats, wetland and coast-dependent jobs and industries are declining, and significant recreational and cultural assets are being lost. Land loss in the state is amplified by the decrease of flood protection from storm surge during extreme weather events such as hurricanes and tropical storms. Wetlands function as a sponge during storm events, absorbing storm surge and protecting inland areas from direct water inundation. The Mississippi River is one of the world’s major river systems in size, habitat diversity and biological productivity. It is also one of the world's most important commercial waterways and one of North America's great migration routes for both birds and fishes. The Mississippi River watershed is the fourth largest in the world, extending from the Allegheny Mountains in the east to the Rocky Mountains in the west. It encompasses over 40% of the contiguous US, spanning 31 states and two Canadian provinces. 60% of all the fresh water flowing into the Gulf of Mexico comes through the Mississippi River.
The summer of 1927 began with one of the signature events of the twentieth century: on May 21, 1927, Charles Lindbergh became the first man to cross the Atlantic by plane nonstop, and when he landed in Le Bourget airfield near Paris, he instantly became the most famous person on the planet. Meanwhile, the talented Babe Ruth was beginning his assault on the home run record, which would culminate on September 30 with his sixtieth blast, one of the most durable records in sports history. During that same year, the American south was clobbered by unprecedented rain and by the flooding of the Mississippi basin, a great human disaster that changed the course of the Mississippi river… literally. The Great Mississippi Flood of 1927 was the most destructive river flood in the history of the United States, with 27,000 square miles (70,000 km2) inundated up to a depth of 30 feet (9 m). To try to prevent future floods, the federal government built the world's longest system of levees and floodways. To address this disaster Congress passed the Flood Control Act (FCA) of 1928 that ultimately led to the levee system as we know it presently.
Can we still call it a River?
The Mississippi river no longer fits the true definition of a river as "a natural watercourse flowing towards an ocean, a lake, a sea, or another river." Rather, this waterway has been shaped in many ways, big and small, to suit human needs. We've succeeded in turning the Mighty Mississippi into a controlled canal. While it maybe not be tamed, it's far from wild -- and understanding the floods that are expected to crest in Louisiana in the future means understanding dams, levees, and control structures as much as rain, climate, and geography.
In my humble, unscientific opinion, I believe we are dealing with a big water issue. Freshwater and saltwater intrusion, in two directions. Freshwater coming down the Mississippi and saltwater pushing up from the Gulf of Mexico. This is what I want to document.