The Problems Underlying New Orleans

Nothing can be built without a firm foundation, like the case of New Orleans, Louisiana. New Orleans, located on the large Mississippi River Delta, has been losing its natural foundation due largely to subsidence. The loss and compaction of soil underneath the city have not only sank the delta deeper beneath sea level, they have also weakened the delta’s ability to absorb shocks from major storms such as Katrina. Consequently, New Orleans fell down when hurricane Katrina invaded in 2005. The city is destroyed along with its culture, economics, infrastructure, agriculture -- all gone. From New Orleans and Katrina, we all learned a powerful lesson about the importance of our land’s natural foundation.

Subsidence has been eating away New Orleans’s foundation for over fifty years for various reasons. Eastern New Orleans is situated on the 7km Michoud fault -- the junction of two tectonic plates of the Earth’s surface. However, instead of shaking the foundation of New Orleans, the fault has caused over 73% of the subsidence in the area over the past 40 years, causing the land to sink 1.7 inches over the mere two-year period from 1969 to 1971. To worse the situation, petroleum and natural gas production -- a great 200,000 barrels of oil and 270 million cubic feet of gas -- have left the soil hollow and have quickened soil compaction. In addition, changing chemical compositions in the same soil has …. (please fill this part in for me, I didn’t quite understand when Maita explained). Thus, the Mississippi River Delta and New Orleans, in particular, have lost both height and protection.

Normally, nature compensates New Orleans for the subsidence due to the Michoud fault by restoring sediments along the Mississippi River bank. However, inhabitants built levees that controlled the Mississippi River and prevented further sedimentation. As a result, marshland and wetland have been decreasing at a pace of the area of one football field per 35 minutes, or 117 square kilometers per year. Such fast pace drains the delta of its protections from strong hurricanes such as Katrina. For the quick pace of subsidence and loss of marshland, New Orleans is in a deeper and deeper hole (and literally so) that is impossible to climb out as these conditions continue.