The west end of Dauphin Island, from the little red schoolhouse to the end of the road, has been receding since 1970. The data analysis used here stops at the west end of Bienville Road and does not include the undeveloped western end of the island. The shoreline change was so severe that the pilings supporting several houses were in the surf consistently throughout 1999. These houses were very close to the surf occasionally prior to Hurricane Georges (1998).
In the spring of 2000, sand was placed along most of these beaches as part of what is locally referred to as “the berm” project. This was a post-disaster, emergency response to stop the regular overwashing of the island that occurred during late-1998 and 1999 because Hurricane Georges had removed the sand dunes. Sand was placed on the upper portion of the beach profile to widen the beach and create some dune elevation. Where there was no room on dry land for the sand to be placed seaward of the houses (i.e. they were in the surf), sand was placed in the surf to widen the beach. For this reason, a portion of “the berm” can really be considered as a beach nourishment project. The behavior of the sand since construction appears consistent with accepted scientific principles and engineering models that predict the fate of beach nourishment sand. Sand has eroded from the seaward side of portions of the “berm” and moved both offshore and alongshore. Today, some of the sand is still there and the regular, cross-island overwashing does not occur. Unfortunately, since there was no formal post-construction monitoring, the overall performance can only be discussed in fairly subjective terms.
This portion of "the berm" on Dauphin Island is partially eroded
This portion of "the berm" on Dauphin Island still exists today
A primary cause of erosion on Dauphin Island in the last several decades appears to be the Mobile Ship Channel. Specifically, the offshore, deepwater disposal of dredged sand has caused the western beaches of the island to erode. Millions of cubic yards of sand have been removed from the littoral system (the wave-driven, sand-sharing system that includes the beaches and sand bars) near the Sand Island Lighthouse in the past several decades. The lighthouse is several miles “upstream” in the littoral system from the west end beaches. Sand naturally moves along the Sand Island and Pelican Island beaches and shoals to Dauphin Island. The amount of sand removed from the system at the ship channel is greater than the total amount of beach erosion on Dauphin Island.
In March 2000, the Dauphin Island Property Owners Association filed a lawsuit against the federal government concerning this beach erosion. The federal government (Corps of Engineers and Justice Department) is apparently fighting every aspect of the suit much as they have done in other similar lawsuits around the country. Although the legal and policy issues may be complex, a technical solution is clear: this report recommends beach nourishment and artificial sand bypassing of all dredged sands in the future. Bypassing means the sand should be placed directly on the beaches of Dauphin Island and in the shoals around the Sand Island Lighthouse. This would restore the natural process that the ship channel has to interrupt.