Southeastern Section - 60th Annual Meeting (23–25 March 2011)

Paper No. 10
Presentation Time: 5:10 PM


CLEARY, William J., Center for Marine Science, University of North Carolina -Wilmington, 5600 Marvin K. Moss Lane, Wilmington, NC 28409-4103,

Most chronic erosion zones located in SE NC are associated with contemporary tidal inlets. However, several unique erosion hot-spots have existed for more than a half-century which are by-products of the historic closure of New Inlet (18th/19th C). New Inlet opened in 1761 along the spit extending from the Fort Fisher Headland. The breach located ~ eight miles NE of the Cape Fear River Inlet (CFRI) became the primary entry to the Wilmington Harbor by 1840. Within several decades of opening the inlet had adversely affected commerce by shoaling of the navigation channel and sequestration of a portion of the discharge that led to a significant decrease in the CFRI bar channel depths.

New Inlet was closed in 1881 by the construction of a massive dam that led to an increase of the CFRI tidal prism and an associated increase of the bar channel depths (6.5 ft à 14 ft). Restoration of the discharge ultimately led to channel straightening that was augmented by dredging and storms of the 1880s. Subsequently a major breaching event triggered the transfer of ~ 17 M cy of material to Bald Head Island (BHI) that resulted in as much as 2,100 ft of progradation by 1914. Additional deepening of the ebb channel eliminated west to east sand bypassing and as a result the BHI oceanfront has retreated between 250-500 ft since 1942. Since development began (1970s) futile erosion mitigation efforts have included the placement of sand bag groins and numerous beach fill projects.

Closure of New Inlet also impacted the updrift Fort Fisher/Kure Beach shoreline reach by the removal of the wave sheltering effect of the former extensive ebb delta. Since closure the oceanfront has retreated by as much as 900 ft. Chronic erosion has led to the emplacement of groins, sand bag armoring and eventually the construction of a seawall fronting Fort Fisher.