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Terminal Groins



The North Carolina Coastal Federation has defined and described three types of constructed “hard structures” built into waterways. The most familiar of these structures is a jetty, which typically is a concrete or rock structure that is “built perpendicular to the shore, usually at inlets, and extends out into the water.” Jetties are designed to block the current moving down the beach. This holds sand in place and prevents the end of the island from washing away and prevents the inlet channel from filling with sand.


A groin is built perpendicular to the coast and works similar to the way a jetty works. However, “groins are usually smaller than jetties and built on straight stretches of beach, not near inlets or channels. They are often built in a series of parallel structures on one section of beach and can be made of wood, concrete, steel or stone.” A terminal groin is a relatively new type of construction. It is the name given to small jetties that are built at inlets — the terminus of islands. Unlike jetties, terminal groins are designed to stabilize the island but offer no extra stability to the inlet (Young, 2017).


A sea wall is typically made of concrete or stone and is built along the coast between the land and the ocean. They can be very large structures (North Carolina Coastal Federation, 2017). All three types of hard structures are typically used to try to control erosion.

Perspectives: Pros and Cons of Terminal Groins

Proponents of terminal groins identify two primary benefits:


     1. They are necessary in some cases to protect beach areas, beach homes and other buildings, and to protect roads. Instances, such as Ocean Isle Beach, are cited to show that one alternative to terminal groins – sandbags – has been ineffective in preventing beach erosion. Some houses on the eastern tip of Ocean Isle Beach have been overtaken by the ocean forcing condemnation. Additional houses are threatened. Many houses (approximately 20) have been physically relocated from the east end of the island.


     2. Although very expensive, terminal groins represent the lowest-cost option for a permanent solution to beach erosion. They can replace the continual stocking of sandbags on the beach and reduce periodic beach re-nourishment costs.


Critics of terminal groins identify four primary harms:


     1. They usually cause increased erosion further down the beach. Both jetties and groins, for example, act like dams to physically stop the movement of sand. They work by preventing longshore drift from washing sediment down the coast. As a result, they cause a buildup of sand on the side protected by the structure — which is precisely what they’re intended to do. But areas further “downstream” on the coast are cut off from natural longshore drift by these barrier-like structures. No longer replenished by the sand that usually feeds them, these areas experience worsened erosion (North Carolina Coastal Federation, 2017). As such, terminal groins simply relocate the problem rather than solving it.They are very expensive to build and maintain. The North Carolina Coastal Resources Commission estimates that groins will cost an average of up to $10 million to build and up to $2 million per year to maintain. Plus, they do not eliminate other costs. Scientific studies of terminal groins already in place in other states show that a sizable amount of money continues to be spent for additional sand for beach re-nourishment.

(Source: North Carolina Coastal Federation


(One terminal groin often leads to the need for another, and then another, etc.)

     2. They create contentious debates within some communities. Local residents who do not live on the shore may not want to be assessed any fee for beach re-nourishment projects.  Paying for groins will become at least equally divisive in the communities that want to build them, pitting property owners at inlets against everyone else. Votes to establish special tax districts for re-nourishment projects are always contentious and have failed when attempted on a countywide basis (e.g., in Carteret and Dare Counties). Even when limited to beach towns, the votes can go either way. It barely passed in Emerald Isle, but failed in North Topsail Beach and Nags Head. When the mayor of Pine Knoll Shore recently floated his taxing proposal, he was shouted down by non-beachfront owners.


     3. They will cause harm to the environment and wildlife. They rob sand that naturally nourishes the beach and accelerate beach erosion farther away. They impact the natural flow of water through inlets and may block the natural shifting of inlet location over time. The ecosystem in the inlet may be disturbed. Plus, they sometimes create desire for additional groins to counter the damage from the first one (North Carolina Coastal Federation, 2017).


     4. The vast majority of North Carolina’s coastal geologists oppose the use of terminal groins. n a letter written to the North Carolina Senate during its consideration of ending prohibition of terminal groins, scientists from Duke University, East Carolina University, Meredith College, North Carolina State University, University of North Carolina – Chapel Hill, and Western Carolina University wrote the following (Beachapedia, 2017):

We are not anti-development. Nor are we an environmental lobby. We are simply electing to play our role in helping the state develop sound, science-based policy. These opinions do not represent the actual or implied positions of our host institutions.


In 2003, the North Carolina Legislature voted unanimously to ban the construction of new, permanent erosion control structures from North Carolina’s ocean shorelines (including inlets) in Session Law 2003-427. There were no dissenting votes in either chamber! This unanimity results from the recognition that the CRCs ban on coastal hard structures enacted in 1985 had served the state well. It was, and is, sound fiscal, environmental, and management policy. Overturning or weakening this ban would be a mistake.


S832 would permit the construction of “terminal groins.” As proposed, these structures could/would be constructed at inlets or “on an isolated segment of shoreline where it will not interrupt the natural movement of sand.” In other words not just at inlets.


The following comments argue against permitting this exception to our state’s long-standing, hard structure ban from a scientific perspective:


   a. Any coastal structure designed to trap or hold sand in one location will, without question, deprive another area of that sand. In simple terms, any structure (including terminal groins) that traps sand will cause erosion elsewhere. Permitting the construction of terminal groins will harm the coast and place downdrift property at risk.


   b. An open letter signed by 43 of the country’s top coastal scientists reports: “There is no debate: A structure placed at the terminus of a barrier island, near an inlet, will interrupt the natural sand bypass system, deprive the ebb and flood tide deltas of sand and cause negative impacts to adjacent islands.”


   c. Proponents of S832 point to the terminal groins at Beaufort Inlet and Oregon Inlet as success stories. These structures have also been referred to as jetties in the past, but we will use the terminology in S832. Our data indicate that beaches in the vicinity of both structures have required huge volumes of beach nourishment for decades (at least 20 million cubic yards of sand at a cost $43 million, without an adjustment for inflation). Therefore, these two structures have, at best, had no impact on the stability of the island adjacent to the structure, and at worst, have caused downdrift erosion necessitating massive renourishment. Dr. Stan Riggs has published detailed analyses indicating that the structure at Oregon Inlet has impacted the stability of Highway 12 on the Outer Banks and required its constant maintenance.


   d. The structures proposed in places like Figure 8 Island and Ocean Isle are on the downdrift side of the neighboring inlet. A shore-perpendicular structure, placed at the downdrift side of an inlet, will block the natural flow of sand onto the island where the structure is located. This will cause an increase in shoreline erosion in front of oceanfront homes downdrift of the structure. Protecting homes at the inlet will be at the expense of a larger number of homes down the beach.


   e. The unfettered flow of sand through natural inlets is an important mechanism maintaining barrier island health. Blocking this flow of sand will inhibit the ability of the barrier island to respond to rising sea level and storms.


   f. Project proponents indicate that the structures will be made “leaky” or permeable so that sand will move to downdrift beaches. This is a classic example of “having your cake and eating it too.” The principle of conservation of mass indicates that one cannot build a structure that will both trap sand and still allow the constant flow of the original budget of sand downdrift.


   g. Groins can impact nearshore circulation by directing currents offshore, especially during storms. Groins can be particularly destructive following storms if a significant portion of the nourishment project is transported offshore, leaving the groin uncovered. During this period, the groin will block all longshore transport until the cell is filled in again.


3.  Additional considerations:


   a. One of the many benefits of the hard structure ban to North Carolina coastal communities is the general lack of lawsuits related to erosion control structures. In contrast, the state of Florida which permits coastal hard structures is awash in constant lawsuits (property owner versus property owner, community versus community). This leaves many coastal management decisions up to the courts. This poor method of public beach management is one that we have largely avoided in North Carolina. If terminal groins are built along the North Carolina coast, rest assured that there will be lawsuits and legal battles related to those structures and the erosion that they may, or may not have caused.


   b. Because the S832 does not define the size or specific design of a terminal structure, the bill leaves the door open to building structures that go well beyond a simple groin. The design floated for Figure 8 Island is not a terminal groin as much as it is an inlet shoreline seawall. Structures like these would destroy the natural function of the adjacent inlets.


   c. In short, we believe that the science overwhelmingly supports maintaining the state’s ban on hard structures. Terminal groins are not new technology. They will harm downdrift property owners.

History of Terminal Groins in North Carolina

Historically, North Carolina has tried to avoid the problems than can be brought on by the use of hard structures to control erosion. In 1985 the North Carolina Coastal Resources Commission (CRC), a policy-making body for the coastal management program, studied the effects of hard structures on beaches in other states. The CRC concluded that the potential negative effects of such structures could cause irreversible damage to North Carolina’s beaches.


As a result, the CRC recommended banning the construction of hard structures to protect buildings at the coast. The ban made exceptions for protecting historic buildings that could not be moved and for maintaining important waterways needed for navigation, such as Oregon Inlet in Dare County.


The regulatory ban on hard structures existed in practice for 15 years before it was upheld in court in a 2000 case. In 2003 the North Carolina General Assembly voted unanimously to formally adopt the hard structures ban as law. The law banned the construction of most new, permanent erosion control structures on the beach but contained the same exceptions as the regulatory ban. The state’s environmental community has consistently supported this prohibition on these hard structures (North Carolina Coastal Federation, 2017).


Some beach communities, led by Figure Eight Island, have long lobbied for an exception to the legislative ban to allow “terminal groins.” They contended that these small jetties would successfully control erosion, and thus reduce beach re-nourishment costs, and that they would neither lead to environmental harms nor accelerate erosion further down the beach. In 2008, the North Carolina Senate passed a bill to allow “terminal groins,” but it went nowhere in the North Carolina House.

The legislature did, however, direct the Coastal Resources Commission to study terminal groins. The engineering consultants who were hired reported that they found no scientific evidence that terminal groins would not harm beaches and no scientific evidence that they would not reduce beach re-nourishment costs [notice the double negatives]. This convoluted wording led the commission to neither go on record upholding the law nor recommending that it be rescinded (Hargrove, 2014). Recognizing the subject’s political volatility, it instead recommended that the legislature attach environmental and fiscal conditions to any bill that allowed groins.


In 2011, the North Carolina General Assembly repealed the 30-year-old ban on hard structures and allowed up to four “test” terminal groins to be built in North Carolina. Subsequently, permit applications for construction of a terminal groin were received from Figure Eight Island, Ocean Isle Beach, Holden Beach and Bald Head Island. The necessary steps to receive a permit to construct a terminal groin include preparation of an environmental impact statement proving that other methods of erosion prevention aren't feasible as long-term solutions. These efforts are currently underway. In 2015, without waiting to see the results of the pilot study, the General Assembly passed a bill that would allow two more terminal groin projects to apply for the required permits (North Carolina Coastal Federation, 2017). Later, these were identified as North Topsail Beach and Bogue Inlet.

Terminal Groins in Brunswick County


Bald Head Island

In 2015, Bald Head Island became the first beach community in North Carolina authorized to build a terminal groin. The island was awarded a permit for construction of a terminal groin of a length up to 1,900 feet to be located at the Point, an area of high erosion located between the island’s South Beach and West Beach. The total cost of the project is expected to be $18 million. Nearly 90 percent of Bald Head Island voters supported the bond that will pay for the terminal groin. The island expects the groin to retain beach width and reduce the frequent need for shoreline re-nourishment projects, each of which costs millions of dollars.Construction is now underway on the first phase with a second phase to begin in 2019.

Ocean Isle Beach

In March 2017, Ocean Isle Beach received a federal permit to build a 750-foot terminal groin. Construction is expected to begin by the end of the year. Town officials are in the process of selecting a contractor and discussing how to pay for the project, the initial construction cost of which is $5.7 million. The 30-year cost of the project is an estimated $45.8 million. The project calls for placing about 264,000 cubic yards of sand dredged from Shallotte Inlet behind the structure. Dredging and fill-in of sand placed behind the terminal groin is scheduled to take place about every five years. The terminal groin would be designed to mitigate erosion along 3,500 feet of the town’s oceanfront shoreline west of Shallotte Inlet. The proposed project will have a 300-foot shore anchorage section made of either concrete or steel sheet piles. The pile will tie into a mound of large armor rock that will stretch 750 feet seaward (Beachapedia, 2017.)

(Source: U.S. Army Corps of Engineers)

The U.S. Fish and Wildlife Service’s biological opinion determined that the project may affect, but would not jeopardize, the existence of several endangered species, including the piping plover and loggerhead nesting sea turtles. Federally designated essential fish habitat, or EFH, is expected to be adversely affected, according to the National Marine Fisheries Service. Habitat will be modified in the groin footprint and during dredging as well as in disposal areas, according to the record of decision. One of the special permit conditions establishes a work moratorium between April 1 through November 15 to protect fish and protected species during seasonal migrations (Talton, 2017).


The Army Corps of Engineers did determine that the terminal groin may increase erosion along the easternmost point of Ocean Isle Beach but that it would not impact the shorelines in Holden Beach or Sunset Beach, beach towns immediately east and west of Ocean Isle Beach. If the project causes an increase in erosion along neighboring shorelines, the town will have to implement modifications to the terminal groin before it can do any further beach re-nourishment (Talton, 2017).


However, in August, 2017, the Southern Environmental Law Center, on behalf of Audubon North Carolina, filed a challenge in federal court to the Army Corps of Engineers’ approval of a terminal groin for Ocean Isle Beach. The law center contends the Corps violated the National Environmental Policy Act and the Clean Water Act in its approval of the project. The lawsuit claims that the Corps failed to objectively evaluate alternatives to the terminal groin, including those that would be less costly to Ocean Isle residents and less destructive to the coast while protecting properties and wildlife habitats.

Listen to a radio interview with Ocean Isle Beach Mayor Debbie Smith and coastal advocate Mike Giles of the North Carolina Coastal Federation for two perspectives on Ocean Isle Beach’s terminal groin.

Holden Beach

Holden Beach is currently in the process of seeking authorization to build a 1,000 foot long terminal groin with a 120-foot “T” at the end. The planned groin will extend 700 feet into the ocean and be constructed of armor stone. The crest of the groin would be approximately five feet wide and the base would be approximately 40′ wide.  Total cost of the groin is estimated at $34,410,000. Beach re-nourishment would be needed approximately every four years.


Supporters of the project say it is needed as a long-term solution to the erosion problem that has claimed more than two dozen homes on the east end of the beach during the past 25 years. Holden Beach Mayor Alan Holden said he and other town officials are sensitive to the concerns about birds and wildlife, but also bear the responsibility for protecting taxpayers’ investments and the infrastructure on the island - that there is a balance. 

We try to do everything we can to comply with all regulations and take care of our natural assets. We’re not going to do anything to jeopardize that, knowingly. As far as I know, we are in good standing with all of the environmental departments that monitor those kinds of things and we want to continue to stay in good standing.

Working to protect the homes all along the nine miles of beachfront is important to the local and statewide economy. We have to do all we can. We’re trying to work with nature; we’ve studied drifts, east and west, and we think we’re on the right path (Quoted in Hibbs, 2015).

Coastal and environmental groups are opposed to the groin.  The North Carolina Coastal Federation in conjunction with the Southern Environmental Law Center and Audubon North Carolina has launched a website explaining their concerns. The Coastal Federation criticized the proponents’ science and the environmental review process charging that the Army Corps of Engineers failed to comply with requirements established in the National Environmental Policy Act and in other federal laws. “The … (Corps) does not provide the public and decision-makers with a thorough and comparable analysis of reasonable alternatives, thus confining the public information to narrow, selective and targeted information that supports only the preferred alternative,” according to the Coastal Federation’s comments (Hibbs, 2015).


Audubon North Carolina focused on the possible negative impact on birds and other wildlife and the likely inability of the groin to stop beach erosion. (Hibbs, 2015).


Walker Golder, Audubon North Carolina ‘s Deputy Director, stated:

The Environmental Impact Statement a ‘make them go somewhere else’ approach when addressing the effects on birds of the preferred alternative and most other alternatives. It perpetuates the common misconception that breeding and non-breeding shorebirds and waterbirds have alternative places to go when habitat is lost and that, because birds have wings, they will simply move somewhere else. The truth is, the birds are already occupying alternative locations. They have been relentlessly forced to abandon high-quality habitats throughout their range because of habitat loss and degradation (quoted in Hibbs, 2015).

According to Golder, the loss of habitat is reflected in the elevated conservation status of many of the bird species that depend on inlets and barrier islands, including those that depend on Lockwood Folly Inlet. Nearly all can be found on state or federal lists of threatened and endangered species (Hibbs, 2015).

What Can Be Done?

The starting points for doing something about the development of further terminal groins on Brunswick County beaches is the same as with all of the environmental issues covered in this section of the website:

  • Become more knowledgeable about this issue.


  • ·Discuss this issue with others; learn from them and help them learn from you.


  • ·Join forces with groups and organizations that are knowledgeable about environmental issues in general (BEAT!) and about this issue in particular. Organizations have greater access to scientific expertise, have larger budgets, have more contacts with the media, and have the force of combining many voices into one.


  • Advocate for policies that show understanding and respect for natural processes. Examples are government protection of naturally occurring sand dunes (and meaningful penalties for those who ignore regulations), restrictions or prohibitions on building houses or other structures in areas likely to be reclaimed by the ocean, and refusal to relocate naturally occurring inlet locations for the sole purpose of expediting development.


  • Advocate for government agencies and government leaders at all levels to conscientiously try to fulfill their responsibilities toward protection and conservation of the environment.


  • Examine the values and political position on this issue of candidates running for political office. Federal support for a strong Environmental Protection Agency is very important. Support for a meaningful Department of Environmental Quality in North Carolina is very important. Support by North Carolina’s governor and state legislature for taking a scientific approach to consideration of terminal groins is absolutely critical. Look for candidates that emphasize the importance of environmental impact in making decisions about what to do or not do.



Beachapedia. 2017 “State of the Beach/State Reports/NC/Shoreline Structures.”


Drew Hargrove. 2014 “Coastal Erosion in North Carolina: Terminal Groins and the Coastal Policy Reform Act of 2013.”

Mark Hibbs. Mark. 2015 “Groups Blast Town’s Terminal Groin.”

North Carolina Coastal Federation. 2017 “Terminal Groins.”


North Carolina Coastal Resources Commission. 2008 “Report on Weather-Related Needs Along the Coast.”


Trista Talton. 2017 “Corps Oks Ocean Isle’s Terminal Groin Plan.”


Rob Young. 2017 “A Brief Evaluation of the Impacts and Benefits of Terminal Groins.”

Read and See More on Terminal Groins:


Andrew S. Coburn. 2017 A Fiscal Analysis of Shifting Inlets and Terminal Groins in North Carolina.


     This study concludes that the benefits of groins in protecting beach homes from erosion are unlikely to outweigh the costs. It shows that using taxpayer funds to support the value of the relatively small number of threatened beach properties will not return enough tax dollars to make public funding worthwhile.

Ashley Gordon, Emily Hall, Hillary Smith, Justin Pearce, Melissa Whaling, Sara Cleaver. 2016 Property Owners’ Understanding of Erosion Control on Holden Beach, North Carolina Prepared for: Geoff Gisler The Southern Environmental Law Center.


     Summarizes results of a survey of Holden Beach residents on construction of a terminal groin.  Results show a mixed level of understanding of the impact of terminal groins, but most respondents wanted to learn more. There was almost an even split between those supporting and those opposing. Both cost and environmental impact were deemed to be very important.


North Carolina Coastal Federation. 2017 “Lockwood Folly Inlet."


     Brief overview of proposed terminal groin at Lockwood Folly Inlet.


(Sample Scholarly Article) L.J. Pietrafesa. 2012 “On the Continued Cost of Upkeep Related to Groins and Jetties.” Journal of Coastal Research. Vol. 28.

     Analysis of the impact of terminal groins and jetties leads to the conclusion that a moratorium should be placed on their construction. Hardened structures will not stabilize inlets or eliminate erosion, rather they will cause erosion and thus should be banned in perpetuity. Publicly elected officials should tell the whole story and not cherry-pick facts for their own use, and if they do, they should be held accountable. Public funds should not be used for either groin/jetty or re-nourishment projects. This is a misuse of public revenues, and managers who do so should be held accountable.

(Sample Scholarly Book) Whitney Knapp. 2012 Impacts of Terminal Groins on North Carolina’s Coasts. (Masters’ Thesis; Duke University).

     This project examines the potential impacts of terminal groins to North Carolina’s coastline. Biological and physical impacts to the coastal environment were assessed, as well as human and economic impacts to the coastal region. Case studies were conducted to determine the long-term impacts of hard structures in New Jersey and Florida, two states that have traditionally relied on coastal armoring to protect private properties. Results show that faced with rising sea levels, terminal groins are likely to cause more harm than good.


(Sample Scholarly Book) Stanley R. Riggs, Dorothea V. Ames, Stephen J. Culver, David J. Mallinson. 2011 The Battle for North Carolina's Coast: Evolutionary History, Present Crisis, and Vision for the Future. University of North Carolina Press: Chapel Hill.


     The North Carolina barrier islands, a 325-mile-long string of narrow sand islands that forms the coast of North Carolina, are in jeopardy. Four experts on coastal dynamics examine issues that threaten this national treasure.

(Video) Dr. Stanley Riggs: “Geological Perspective — Dr. Stan Riggs Explains the Consequences of Terminal Groins.”


     A clear description of barrier islands and terminal groins by a leading expert.

Sample of Scholarly Journals:

  • Coastal Engineering

  • International Journal of Water Resources and Environmental Engineering 

  • Journal of Coastal Research

  • Journal of Marine Science and Engineering

  • Ocean and Coastal Management

  • Southeastern Geology

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