Dauphin Island is Alabama's only barrier island. The island is crucial to forming Mobile Bay, the fourth largest estuary in the United States. In 2007, the US Geological Survey reported Dauphin Island has been eroding since 1958, with the erosion rate accelerating in the 2000s. The erosion correlated with periodic deepening of the entrance channel from the Gulf into Mobile Bay. Dredging operations interrupt the natural flow of sands along Alabama beaches from east to west across the mouth of the bay, causing Dauphin Island to be starved of sand.
For years, the Corps of Engineers has maintained dredging of the entrance channel does not contribute to Dauphin Island's erosion. The Corps even defended that position in a 10-year lawsuit lodged by Dauphin Island's small population against the US Government. The lawsuit was settled in 2009, with the Government paying $1.5 million in return for the citizens agreeing to give up their rights to ever sue the Government again over the erosion issue. And, Dauphin Island continued to erode.
In 2016, the Corps began a study to deepen and widen the Mobile Harbor ship channel to a depth of around 50 feet in a bid to compete with other eastern seaboard ports for the massive new container ships now transiting the Panama Canal. A major environmental concern of this new attempt to enlarge the entrance channel, is how it could further affect Dauphin Island's erosion problem.
At a February 22 public meeting, for the first time the Corps admitted thatthechannel maintenance program is contributing to the erosion of Dauphin Island. Half of the sands dredged from the entrance channelhave beeneffectively removed from the nearshore littoral drift systemsince 1999, when the Corps began placing sands in the current disposal site. In short, around 7 million cubic yards of naturally provided and irreplaceable beach quality sands have been preventedfrom nourishingDauphin Island over the last 19 years. That represents a significant cumulativeloss of sandsthat is contributing to the sand-starved nature of Dauphin Island and its observed erosion. And the loss is magnified each time the entrance channel is dredged.
The questions now are: What is the Corps going to do to mitigate for the significant adverse impacts caused by the historic maintenance of the entrance channel? And, how will similar impacts be avoided in the future if the channel is deepened and widened as proposed by the Alabama State Port Authority? The concerned public needs to make sure the Corps develops adequate answers to both questions to protect our State's coastal resources.
Submitted by Glen Coffee