Louisiana’s Coastal Land Loss

Louisiana’s Coastal Land Loss

A growing concern for the people of Southeast Louisiana is the state’s coastal land loss which has been occurring with increasing speed in the last few years. This land loss is a result of the parasitic relationship between nature and men.

From the time that Louisiana has been settled, people have altered the natural form of the land in order to accommodate their own personal interest. Louisiana has lost around 1,900 square miles since the 1930’s, accounting for 90% of the coastal marsh loss in the lower 48 states (USGS 2003). Various articles from Louisiana research centers and environmental preservation groups have been gathered in order to provide valuable information on what is causing the problem and how to fix it.

There are four main reasons as to why Louisiana is experiencing this issue of growing concern:

• Levee construction affects the river’s natural course which is changing overtime. As long as people have been living in the surrounding area of the Mississippi River, they have been building levees. “By 1812, settlers built levees on the east bank to Baton Rouge, 130 miles upstream, and on the west bank as far as Pointe Coupйe, 165 miles upstream” (Tibbetts 2006). While they keep our homes from flooding, levees do not allow the soils that are carried by the water to deposit in the floodplains, thus preventing the coast from expanding and doing the opposite. In addition, people that live on sinking land are protected by levees but are more vulnerable to flooding because the land continues to sink without fresh soil deposits (Environmental Literacy Council 2006). By altering the river’s natural course, sediment deposits gathered all the way from Minnesota are now useless.

• Canals that have been dug into the delta allow saltwater intrusion. The oil and gas industry are responsible for canals that have been dug in order to explore and transport chemical products across the delta. “There are currently 10 major navigation canals and 9,300 miles of pipelines in coastal Louisiana serving about 50,000 oil and gas production facilities” (Tibbetts 2006). These numerous canals allow the saltwater from the Gulf of Mexico to enter the floodplains and kill the growing vegetation, thus eliminating the plants’ root systems to hold the loose delta soil in place (Environmental Literacy Council 2006). In other words, with the loss of vegetation the soil is left undefended to the exposure of the sea waters.

• The subsidence of alluvial soils. Soils from the region naturally sink under their on weight. “The underlying deposits then compact, and, without additional soil being added on top, the overall land-level drops below sea level” (Environmental Literacy Council 2006).

• Sinking continental crust. Since more earth is deposited in top of the crust, this forces it downward in a process called “downwarping” (Environmental Literacy Council 2006). As a result, the barrier islands that protect most of Louisiana from natural phenomena such as hurricanes are also sinking, leaving the land vulnerable to flooding and land erosion.

In the figure below, it can be seen that coastal land loss is a major concern even without Hurricane Katrina’s help. But the combined land-water changes caused by Katrina and Rita exceeded all such changes in coastal Louisiana from previous recent hurricanes combined (USGS 2006).

Figure 1

Coastal land loss in Louisiana

This environmental concern is growing so different agencies and organizations are currently working on projects that will allow Louisiana’s coastland to once again rise.

Some of these projects include:

• Coastal Wetlands Planning, Protection, and Restoration Act. This act was passed in 1990 with the purpose of providing about $50 million each year for wetlands restoration projects in Louisiana. “The Breaux Act has provided funding for 118 restoration projects, and 75 projects have already been built” (Tibbetts