Sunday, January 13, 2013

Dredging- A Temporary (not to mention expensive) Solution to a Permanent Problem

Citing "Hurricane Sandy, two back-to-back nor’easters and several winter wind storms" the North Carolina Department of Transportation has once again suspended ferry service and opted to dredge the "uncooperative" Hatteras Inlet channel. Before I digress, let me take you back to the year 1828. The location, some 15 odd miles south of the current topic of Hatteras Inlet. Nearly 185 years ago, the United States Congress allotted 20,000 dollars in an effort to dredge and maintain the vitality of Ocracoke Inlet (Alexander and Lazell, 1992) the hub of 19th century North Carolina maritime activity as neither Oregon nor Hatteras Inlets had been opened and New Currituck Inlet had just closed (Stick, 1958). In less than ten years (eight to be exact) the Army corps of Engineers had "worn out two dredges and were working on a third" with their work and time yielding very little progress in return (Alexander and Lazell, 1992). Alexander and Lazell note on page 55 of their work "Ribbon of Sand" that "by the time channels were dredged from sea to sound, their mouths would have already shoaled up again. Over the course of the winter, whole channels would simply disappear. Finally, in 1837, Congress appropriated additional funds to build a jetty to protect the Ocracoke channel. But just before the jetty was complete a violent gale destroyed it. Thus between 1826 and 1837, Congress had spent nearly 133, 750 dollars to stabilize the inlet, and had nothing at all to show for its largess".

Ocracoke Inlet as of 2009, showing significant shoaling, along with both ebb and flood tide deltas.
        This example goes to show that the laborious  process of inlet dredging, shoaling, and re-dredging is surely not something new. Many experts see dredging and inlet stabilization as simply a temporary solution to a permanent problem, as the inlets serve as huge financial burdens.Admitted no two inlets behave in the same fashion, most will indeed shoal up over time, simply due to natures natural processes of barrier island dynamics.Aside from Ocracoke and Hatteras Inlets, Oregon Inlet, further north on the banks has problems of its own as well. In fact, the Army Corps of Engineers said it would need between "$12-15 million each year to keep Oregon Inlet operational" ( With a dwindling budget for dredging operations, the processes of inlet stabilization and dredging will need a more coast effective solution.
         With growing year-round populations on the banks, and more prosperous cities along the sounds of the inner-banks, dredging and inlet stabilization will continue well into the future. However, those in charge of dredging at the Army Corps of Engineers and the North Carolina Department of Transportation must become aware of the natural processes they are interfering with. Constant dredging disrupts natural sand transport which helps to develop flood tide deltas on the sound side of the island, which actually helps increase barrier island width. So instead of viewing the inlets through a stirctly anthropogenic lens, and thinking about what we need to do to keep them in order, perhaps we as humans should look at them through a lens which helps us to realize what the inlet is doing to keep us in order.

"Man is the barrier islands greatest enemy, not the sea"- Paul Godfrey, Ph.D

Link to the recent article concerning the dredging of Hatteras Inlet-


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