Hurricane Gustav and Louisiana's Coastal Wetlands
I am watching the weather forecasting models project paths for soon to be Hurricane Gustav into the coast of Louisiana. As this occurs, I find myself reflecting on the federal government and the Corps' efforts (and in some cases lack thereof) for the past three years with regard to coastal restoration and hurricane protection. The efforts to rebuild and improve hurricane protection levees around New Orleans are considerable but far, far from complete. The federal government and the Corps' efforts at coastal restoration during the same period are almost non-existent.
If Hurricane Gustav were to strike New Orleans, we can only speculate at the results and the impact that another hurricane will have on coastal restoration efforts. My predictions, however are as follows: 1) the levees in lower St. Bernard Parish will be breached and over topped; 2) the lake will not flow into New Orleans proper as long as the Corps is able largely to close off the drainage canals and the industrial canal from the lake and the Gulf; 3) the city will experience significant flooding, but less than Katrina from the inability of the pumping system to remove the rain water from the streets.
If the city does not fill with lake water and flood a large number of otherwise occupied homes, the hurricane will be further encouragement for the federal government to accelerate and complete hurricane protection and coastal restoration efforts. If an enormous number of otherwise occupied homes are destroyed, the result will be the opposite. It will discourage the government from further efforts to improve hurricane protection levees and from undertaking new efforts at coastal restoration. To stay on track and continue the recovery of New Orleans and Louisiana's coastal wetlands, the efforts of the government up to this date will need to show signs of success.
Ironically, the coastal wetlands below New Orleans are largely gone because of unintended but not necessarily unanticipated consequences of Mississippi River flood control and navigation improvement undertaken by the federal government and the Corps after the 1927 Mississippi River flood and continuing into the 1970's. The cause of coastal wetland loss in Louisiana is largely the result of the changes in the Mississippi River system outside of Louisiana undertaken by the federal government and the Corps for the benefit of commercial interests often far removed from Louisiana. Yet in spite of the fault of the federal government and the Corps, further damage to New Orleans and southeastern Louisiana may well discourage further efforts to restore New Orleans and Louisiana's coastal wetlands. In the aftermath of another hurricane, the situation may be presented as a hopeless and largely the result of local causes.
The reality behind all of these events is that the federal government and the Corps have known since the wetlands began eroding away in the 1930's that the coastal wetlands were subsiding and dependent on new sediment from the Mississippi River to offset the subsidence.
By reducing the sediment load in the river as the result of construction of dams and reservoirs (primarily on the Missouri and Arkansas Rivers) and by containing the river within levees, the federal government and the Corps knew before their efforts began that a result of these undertakings would be the loss of coastal wetlands in Louisiana. It is not difficult to find academic and government reports back into the 19th century acknowledging the process of regional subsidence offset by sedimentation from the Mississippi River. I would by happy to provide more detailed references to those who need them.
Now, we wait to see the extent to which the consequences of the sins of the federal government and the Corps will be visited upon the City of New Orleans and the coastal wetlands of Louisiana yet again as a result of Gustav.
Erich P Rapp.
