One thing that many people who live in New Orleans do not realize is that the ground on which we walk, build, and live is extremely young. All of the soil that makes up the land of Southeast Louisiana is under 4,500 years old. To give a bit of perspective, that means early humans were already developing agriculture in the Mediterranean and Europe when our soil was just being deposited! Our soil is also not native to our area, but was brought here by the Mississippi River from places as far away as Montana. Over millennia, the boulders eroded and became rocks, the rocks became stones, and the stones became clay. The clay and finer particles are what made it to the greater New Orleans area, and are what we build our homes on today.
The neighborhood of Marlyville-Fontainebleau was once a swamp, which is extremely influential as to the soil that is found here. This neighborhood is made up of two types of soil – Sharkey Clay and Harahan Clay. The latter makes up the majority of soil in this area, and is the finest possible sediment. Sharkey Clay is generally located in the portions of the neighborhood closer to the river, that may have been the banks of what early New Orleans residents called the “backswamp.” Sharkey Clay is slightly less fine than Harahan clay, and therefore less susceptible to subsidence, or settlement.
You may be thinking, “why do I need to know about what kind of soil is in this neighborhood?” The type of soil in a neighborhood is extremely important – influencing everything from how much flood insurance you will pay to what kinds of plants you can place in your garden. The type of soil on which you are building will even influence how you design and construct your home, due to the water table and rates of settlement. Soil may not be the most fun part about choosing a neighborhood, but it is certainly important. The more you know about the neighborhood in which you live or are looking to buy, the better!