What unusual hazards can affect real estate along ocean shorelines? The greatest difference between real estate adjacent to the ocean or an inlet and inland real estate is the hazard of shoreline erosion. For inland real estate, property lines are generally unchanging. However, property on the oceanfront or adjacent to an inlet has a moving property line along the shore that is determined largely by the forces of nature. This moving boundary, called the 'mean high water line,' can change from day to day.
Back to topWhat causes shoreline erosion? Shoreline erosion is caused by a variety of factors. Along the oceanfront, hurricanes, northeasters and other storms cause seasonal fluctuations of the beach.
As a general rule, North Carolina's beaches erode more in the stormy fall and winter months than in the calm summer months. It is not unusual for the mean high water line to move landward temporarily by 75 to 100 feet during the stormy season. Of course, when an ocean shoreline is hit directly by a hurricane, beachfront erosion can be even more dramatic. Inlets are also affected by seasonal storms and can change configuration rapidly and severely as tremendous amounts of water and sand flow through them. In severe storms, it is even possible for new inlets to form and existing inlets to close. Erosion associated with storms is often severe because large quantities of sand can be moved quickly offshore from the beach and dunes. This type of erosion is usually called 'short-term' because the shoreline can return to its original profile as conditions calm.
Back to topDo North Carolina's ocean beaches experience 'long-term' erosion? Yes. Long-term erosion can be caused by a variety of factors, including rising sea levels.
Although this process can cause erosion along the entire oceanfront, areas adjacent to inlets are often the most profoundly affected. Some 'migrating inlets' are constantly moving in one direction. Others may stay in the same general location but expand and contract constantly. These inlets are often called 'oscillating inlets.' In addition to its natural causes, erosion can be set in motion by human activities. For example, a jetty constructed to stabilize an inlet or a structure built to stabilize a beach can trap sand on one side but increase erosion on the other. Such erosion will continue until the structure is removed or the beach adjusts.
Back to topWhat is the typical erosion rate of a North Carolina shoreline? Studies by the N.C. Division of Coastal Management show an average long-term erosion rate of 2 to 3 feet annually for the entire coast over the last 50 years. However, the annual erosion rate is more than 20 feet for some shoreline areas, while others have been relatively stable. Ocean shorelines near inlets and inlet shorelines usually experience the greater fluctuations.
Oceanfront property is also subject to seasonal storm-related fluctuations that can result in short-term erosion of between 75 and 100 feet. Although most of this erosion is temporary, some land area lost to storms may not return. [For information on erosion rates, contact the Division of Coastal Management or the local building official in the jurisdiction where you plan to purchase or build. There are also a few private companies that analyze shoreline hazards for a fee.]
Back to topWhat building construction features help reduce or prevent storm damage? Several features can prevent or substantially reduce the likelihood of damage from severe storms or erosion. Pilings can raise the first floor above expected flood elevations and waves. In many areas, embedding the tip of pilings deeper than five feet below sea level can help a building stand during severe erosion. Any walls constructed between pilings should be designed to break away when hit by waves to prevent damage to the elevated portion of the building.
Elevating a building to protect it from storm surge and flood increases its exposure to storm winds. The key to reducing storm wind damage lies in the quality of the building's design and construction. For new homes on the beach, consider employing a professional engineer to help ensure adequate structural design. If buying an existing home, an engineer can help assess the structure's strengths and weaknesses, and suggest modifications to make the house more damage-resistant.
Modifications may include: addition of hurricane clips to improve the roof's ability to withstand uplift forces of high winds; installation of storm shutters to protect window and door openings from wind-driven rain and debris; improved attachment of roof shingles; reinforcement of gable end roofs; reinforcement of the attachment of plywood roof decking to roof rafters with additional nails, screws or adhesives; and reinforcement of the attachments of porches and decks.
Sand dunes also provide significant protection during the most severe storms. You can protect and enhance frontal dunes by keeping vehicles and people off these areas, and planting additional dune grasses. Keep in mind that sand dunes protect against short-term erosion caused by very severe but infrequent storms and offer little protection from long-term erosion.
Back to topDoes the Outer Banks have beach nourishment?Most areas of the Outer Banks have no plan and system in place to nourish the beach. The town of Nags Head has a plan in place to nourish the worst eroded areas of the town today. State and Federal funding for beach nourishment has been difficult to obtain for Dare County beaches.
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