Erosion Control-Part I
In January, 2005, the Army Corps of Engineers began an erosion control project in which sand dredged from the ship channel through Beaufort Inlet is being pumped to rebuild, or “renourish”, the Fort Macon State Park beach. The sand is desperately needed to repair the ravages of natural forces in recent years. Yet this project is but the latest part of a struggle that has gone on for almost two centuries. What follows is an overview of the efforts that have taken place to protect and preserve Fort Macon from the restless Atlantic.
Since its construction, a constant battle between Fort Macon and the Atlantic Ocean has been waged. As with all permanent structures built on barrier islands, Fort Macon has been at times threatened by the natural forces that are constantly at work reshaping and changing Bogue Banks and Beaufort Inlet.
By the very nature of its purpose, the fort had to be built of necessity in the most disadvantageous of locations: close to the shoreline on a barrier island adjacent to a major inlet. It has only been by very strenuous and expensive government efforts that the fort and its surrounding beach have been enabled to stay intact through the continual assault of Nature.
North Carolina’s barrier islands are constantly in a state of change. They expand and recede over time. Likewise, the inlets through these islands open, close, and shift as the years go by. Beaufort Inlet, flankedby Shackleford Banks on the east and Bogue Banks on the west, is no exception. Natural shore migration at Beaufort Inlet takes the form of alternately eroding and then building up the shoreline at Bogue and Shackleford Points as the inlet expands and contracts. This process takes place over an irregular number of years.
As an example of the extremes of the inlet’s fluctuation, consider that during one period of inlet movement, erosion at Bogue Point swallowed up Fort Macon’s predecessor fort, Fort Hampton, in 1825. One hundred years later, the process had reversed in the 1920s, creating a large expanse of land at Bogue Point that boosted the acreage of the newly-created Fort Macon State Park to an unprecedented 581 acres.
The fickle nature of the erosion process at Beaufort Inlet was of great concern to the Army Engineer Department when it began to build Fort Macon on Bogue Point, the eastern end of Bogue Banks. To prevent Fort Macon from having the same end as its ill-fated predecessor, Fort Hampton, it was necessary to take measures to preserve the fort site from the sea. To stabilize the shifting inlet and beach for the establishment of a permanent fort, the Engineer Department initiated a system of jetties along the shore of Bogue Point in 1831 while the fort was still under construction.
Jetties are structures of wood, stone or other materials built to extend from a beach into the water. They slow the water currents moving along the shore and allow sand to build up on the upstream side of the jetty, thus halting the effects of erosion.
These first 1831 jetties consisted of rows of wood pilings laid at right angles to the beach. They were filled with brush that was weighted down with brick bats and logs. They were successful in halting erosion of the fort site for some years. However, these structures were only temporary at best. By 1840 the wood had deteriorated and the bricks were scattered along the beach. The fort was in danger once more.
In December, 1840, Captain Robert E. Lee was sent by the Engineer Department to study the erosion problem at Fort Macon and determine a solution. In January, 1841, Lee sent his recommendation that two permanent stone jetties be constructed to halt the erosion. These would consist of stone piled upon a grillwork of palmetto logs set perpendicular to the shore. The Engineer Department approved the recommendation. In 1842, these two jetties were constructed on the beach near the fort by Lieutenant George Dutton. They proved to be successful. During 1844-45, four more stone jetties were constructed under Lieutenant Daniel P. Woodbury. These six structures held the beach in place for almost forty years.
Following the War Between the States, shore erosion shifted from the ocean beach to Beaufort Inlet. The inlet began to widen, causing considerable erosion at both Bogue and Shackleford Points. Between 1876 and 1881 the width of the inlet increased from 2250 yards to 2900 yards. Of the overall loss of 650 yards of beach between 1876 and 1881, 530 yards eroded from Shackleford Point and 120 yards from Bogue Point.
As a result, Congressional funding was appropriated for improvements to Beaufort Harbor by the Engineer Department. Engineers worked to stabilize both Bogue and Shackleford Points during the 1880s. On Bogue Point at Fort Macon, three new jetties were built on the inlet beach northeast of the fort during 1883-87. During 1883-85, a massive cast-in-place concrete breakwater was constructed on top of one of the old 1844 jetties eastward of the fort. During 1887 and 1889-90, stone revetments were built along the high water mark of the inlet beach northward from the concrete breakwater jetty. These improvements, along with similar work done across the inlet on Shackleford Point, served to stabilize Beaufort Inlet once more.
During 1906, while the Army Corps of Engineers worked on a project to dredge the channel through Beaufort Inlet to a 20-foot depth, an unusual event took place. In December, 1906, part of the inlet beach area north of Fort Macon adjacent to Cowpen Creek suddenly began to crumble and sink into the water. The dock and breakwater for the newly-established U.S. Lifesaving Service Station, which was located near the mouth of Cowpen Creek, likewise just collapsed into the water. The station house itself was left hanging partly over the edge of the crumbling cliff when the phenomenon suddenly stopped.
It turned out the ebb tide of the inlet, probably outflowing with greater velocity as a result of the dredging, had created a scouring action along the bottom of the north side of Bogue Point. The scouring action undermined a portion of the beach until it simply collapsed into the depths. The Lifesaving Station was later moved further inland to its present location, but new corrective measures had to be taken to stabilize Bogue Point.
During 1907-08, the engineers removed one of the jetties built in the 1880s on the north side of the point that was now useless. Its materials were then used to construct four other small jetties along the north side of the point. These managed to prevent further damage to the beach.
On the ocean beach in front of the fort, meanwhile, quite the opposite was happening. After 1908, the ocean beach began to build up at an amazing rate. This buildup was particularly heavy during the 1920s, to the delight of state officials now administering Fort Macon as a state park. It reached its peak in 1930, when the extreme end of Bogue Point became a hook-like sand spit extending about 2800 feet southeast from the walls of the fort. In the center of this hook was a lagoon-like tidal basin.
Paul Branch Jr. continues his discussion of erosion control at Fort Macon in the next issue of the Ramparts. This discussion will be from 1940 until the present day. Paul is the Fort Macon Historian. He has published two books on the fort and numerous articles.