Hazard mitigation in the Outer Banks

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The Outer Banks are the barrier islands along the east coast of North Carolina in the United States. They are extremely sensitive to environmental hazards, particularly hurricanes. Hazard mitigation plans have been created and are implemented when a hurricane is forecasted to strike the Outer Banks. The goal of the plans is to identify the policies and tools that are needed in order to reduce or eliminate the risk of life and property loss from any event that may occur in the Outer Banks. [1] [2]

Contents

FEMA - 8458 - Photograph by Mark Wolfe taken on 09-20-2003 in North Carolina FEMA - 8458 - Photograph by Mark Wolfe taken on 09-20-2003 in North Carolina.jpg
FEMA - 8458 - Photograph by Mark Wolfe taken on 09-20-2003 in North Carolina

Geography

Offshore deposits of sand and other sediments that parallel the coast line collected over thousands of years, forming the long, narrow barrier islands. The long, thin strip of land separates the Atlantic Ocean from the Currituck, Albemarle, and Pamlico sounds. The islands of the Outer Banks travel 325 miles (523 km) along the coastline of North Carolina. The formation protects the coastline from severe storm damage and harbors the many different habitats surrounded by the islands, providing refuge for wildlife. Several islands are separated from each other by tidal inlets which provide a regular exchange between the water of the ocean to bays and estuaries. The barrier islands and sandbars that make up the Outer Banks are highly fragile and are constantly changing their coastal landscape; some of the islands may only be 0.5 miles (0.80 km) wide and may recede back into the ocean over time. [3]

Barrier island zones structure the islands of the Outer Banks from the ocean side to the sound. The beach faces the ocean and consists mainly of sand deposits created by wave action. Dunes of compacted sand and sediment behind the beach deposited by the wind. Front dune ridges may be followed by a secondary line of dunes further inland. Plants naturally found on dunes help to stabilize them by preventing potential damage caused by water and wind with their roots. Behind the dunes are mudflats, which are formed by sediment passing through dune systems by storm winds. Salt marshes fall behind barrier flats in low-lying areas that border the sound side of the island, and are flooded regularly by tides. [4]

Along the beaches of the Outer Banks, plants and beach grasses like Eastern prickly pear, cabbage palmetto, and dwarf palmetto grow. Pindo and windmill palms are not indigenous to the area, but are located in many areas of the mainland. Towards the sound side, seagrasses, aloe yucca and wax myrtles nestle. [5] A maritime forest known as Nags Head Forest is located within Nags Head, and is located on the mainland side of the island. Oak, ferns, pine, magnolias, cedars, willows, goldenrods, and cattails thrive among the forest. Ancient dune swales provide areas to capture precipitation, providing fresh water. [6]

Demographics

North Carolina has 20 coastal counties [7] [8] that are part of the Coastal Area Management Act (CAMA), of which Hyde County, Dare County and Currituck County include the barrier islands. The economic and social demographics of these counties factor heavily into the mitigation and recovery plans, as these statistics allow a better understanding of the necessary mitigation techniques that need to be in place in the event of a natural disaster. The statistics include a number of factors, such as the number of households in the counties and their monthly or annual incomes.

According to the 2010 census, Dare County is the most populated of the three barrier island counties, with a population of 33,920 people, a population density of 100.26, and 383.42 square miles (993.1 km2) of land. The second most-populated county is Currituck, which has a population of 23,547 people, a population density of 101.39, and 261.85 square miles (678.2 km2) of land. Hyde County has the smallest population with 5,810 people, a population density of 9.07, and 612.70 square miles (1,586.9 km2).

The median household income from 2006 to 2010 was $55,376 for Currituck County, $44,167 in Dare County, and $38,265 in Hyde County. The percent of the population below the poverty line was 8.5% in Currituck County, 16.3% in Dare County, and 20.4% in Hyde County.

In the previous year[ when? ] Hyde County received $70,512 in federal funding, Currituck County received $230,625 in federal funding, and Dare County received $725,521, resulting in a total of $1,026,658 in federal funding. [9] [10] [11] [12]

Infrastructure

The largest infrastructure in the barrier islands in terms of mileage is North Carolina Highway 12 (NC 12), which runs north and south along the shoreline of the Outer Banks and includes 138 miles of roadway. NC 12 is the main road that links all of the islands of the Outer Banks together. There are several bridges along the highway, which include the Wright Memorial Bridge, the Virginia Dare Memorial Bridge, the Washington Baum Bridge, and the Bonner Bridge. [13] [ better source needed ]

Hurricanes

The Outer Banks are susceptible to recurring hurricanes. For a storm to be classified as a hurricane, the organized area of intense thunderstorms must develop a well-defined area of surface circulation and maximum sustained winds speeds that measure over 74 mph (119 km/h). Hurricanes are classified into five different categories measured by the Saffir–Simpson scale, which categorizes them based on their wind speeds, barometric pressure, and storm surge. [14]

Hazards produced by hurricanes

Wind damage
Hurricane-force winds speeds can exceed 150 mph. They can easily destroy mobile homes and buildings not built to hurricane code. Intense winds can also uproot trees, damage power poles, tear away house rooftops, and dismantle communication availability and transportation links. The right side of the eye wall has the highest wind intensity.
Inland flooding
Intense rainfalls carried by hurricanes can produce a quick accumulation of storm water that is classified as inland flooding. Hurricanes produce on average rainfalls between six and twelve inches. The risk of inland flooding for the Outer Banks varies upon several circumstances, such as the storm's speed: if a hurricane stalls and moves slow along its track, it has more time to dump rain in an area. If areas have received heavy rainfalls prior to a hurricane, soils may become saturated and become unable to absorb more water. Destructive inland flooding caused by hurricanes can wash away roads and highways. Current building codes for the Outer Banks require the first floor of a house to be elevated nine to ten feet above sea level. Low lying buildings and vehicles can still be damaged by flood waters.[ citation needed ]
Storm surge
As a hurricane makes landfall the ocean surface rises by the force of the storm's winds. Storm surges produced by hurricanes can reach heights of up to 20 feet. The total height of a storm surge during a hurricane has an inverse relationship with the storm pressure and a direct relationship with the hurricane's intensity. When a storm surge pushes through the Outer Banks the sounds and bays fill with water, which recedes through the beach towards the ocean, causing flooding and erosion. Storm surges enhance the frequency of waves and strengthens currents which can severely damage marinas, destroy building structures, wash away coastal highways, and erode beaches. [15]

Hazard mitigation and planning

Counties have their own mitigation plans. Dare County's mitigation plan was last updated in 2010. [16]

Related Research Articles

<span class="mw-page-title-main">Hyde County, North Carolina</span> County in North Carolina, United States

Hyde County is a county located in the U.S. state of North Carolina. As of the 2020 census, the population was 4,589, making it the second-least populous county in North Carolina. Its county seat is Swan Quarter. The county was created in 1705 as Wickham Precinct. It was renamed Hyde Precinct in 1712 and gained county status in 1739.

<span class="mw-page-title-main">Dare County, North Carolina</span> County in North Carolina, United States

Dare County is the easternmost county in the U.S. state of North Carolina. As of the 2020 census, the population was 36,915. Its county seat is Manteo. Dare County is named after Virginia Dare, the first child born in the Americas to English parents, who was born within the county's current borders. Founded in 1870 from parts of Tyrrell, Currituck and Hyde counties, it consists of a large segment of the Outer Banks of North Carolina, along with Roanoke Island and a peninsula of land attached to the mainland. Most of the county consists of a string of resort communities along the Outer Banks. While lightly populated by year-round residents, the population swells during the summer with vacationers.

<span class="mw-page-title-main">Currituck County, North Carolina</span> County in North Carolina, United States

Currituck County is the northeastern most county in the U.S. state of North Carolina. As of the 2020 census, the population was 28,100. Its county seat is Currituck. The county was formed in 1668 as a precinct of Albemarle County and later gained county status in 1739. The name is "traditionally said to be an indigenous word for wild geese; Coratank." Currituck County is included in the Virginia Beach-Norfolk-Newport News, VA-NC Metropolitan Area. It is in the northeastern section of the state and is bounded by the Atlantic Ocean, Currituck Sound, Camden County, Dare County and the Commonwealth of Virginia. Currituck Court House, mentioned as early as 1755, was the name of the county seat. Today the words "Court House" have been dropped and only Currituck is used as the town name.

<span class="mw-page-title-main">Ocracoke, North Carolina</span> Census-designated place in North Carolina, United States

Ocracoke is a census-designated place (CDP) and unincorporated town located at the southern end of Ocracoke Island, located entirely within Hyde County, North Carolina, United States. The population was 948 as of the 2010 census. In the 2020 census, the population had dropped to 797 people.

<span class="mw-page-title-main">Cape Hatteras</span> Cape on the shoreline of Hatteras Island, North Carolina, United States

Cape Hatteras is a cape located at a pronounced bend in Hatteras Island, one of the barrier islands of North Carolina.

<span class="mw-page-title-main">Hurricane Gloria</span> Category 4 Atlantic hurricane in 1985

Hurricane Gloria was a powerful hurricane that caused significant damage along the east coast of the United States and in Atlantic Canada during the 1985 Atlantic hurricane season. It was the first significant tropical cyclone to strike the northeastern United States since Hurricane Agnes in 1972 and the first major storm to affect New York City and Long Island directly since Hurricane Donna in 1960. Gloria was a powerful Cape Verde hurricane originating from a tropical wave on September 16 in the eastern Atlantic Ocean. After remaining a weak tropical cyclone for several days, Gloria intensified into a hurricane on September 22 north of the Lesser Antilles. During that time, the storm had moved generally westward, although it turned to the northwest due to a weakening of the ridge. Gloria quickly intensified on September 24, and the next day reached peak winds of 145 mph (233 km/h). The hurricane weakened before striking the Outer Banks of North Carolina on September 27. Later that day, Gloria made two subsequent landfalls on Long Island and across the coastline of western Connecticut, before becoming extratropical on September 28 over New England. The remnants moved through Atlantic Canada and went on to impact Western Europe, eventually dissipating on October 4.

<span class="mw-page-title-main">Buxton, North Carolina</span> Census-designated place in North Carolina, United States of America

Buxton is an unincorporated community and census-designated place (CDP) on Hatteras Island near Cape Hatteras. It is located in Dare County in the U.S. state of North Carolina. As of the 2010 census, it had a population of 1,273. Located at the widest part of Hatteras Island, it is the largest community on Hatteras Island both in terms of area and population, and is home to the island's schools and other major public buildings and offices.

<span class="mw-page-title-main">Ash Wednesday Storm of 1962</span>

The Ash Wednesday Storm of 1962 occurred on March 5–9, 1962 along the mid-Atlantic coast of the United States. Also known as the Great March Storm of 1962, it was considered by the U.S. Geological Survey to be one of the most destructive storms ever to affect the mid-Atlantic states. Classified as a level 5 or Extreme Nor'easter by the Dolan-Davis scale for classification of Atlantic Nor'easters it was one of the ten worst storms in the United States in the 20th century. It lingered through five high tides over a three-day period, killing 40 people, injuring over 1,000, and causing hundreds of millions in property damage in six states. The storm also deposited significant snowfall over the Southeast, with a regional snowfall index of 12.663.

<span class="mw-page-title-main">Outer Banks</span> Barrier islands in North Carolina, U.S.

The Outer Banks are a 200 mi (320 km) string of barrier islands and spits off the coast of North Carolina and southeastern Virginia, on the east coast of the United States. They line most of the North Carolina coastline, separating Currituck Sound, Albemarle Sound, and Pamlico Sound from the Atlantic Ocean. A major tourist destination, the Outer Banks are known for their wide expanse of open beachfront and the Cape Hatteras National Seashore. The seashore and surrounding ecosystem are important biodiversity zones, including beach grasses and shrubland that help maintain the form of the land.

<span class="mw-page-title-main">Hurricane Dennis (1999)</span> Category 2 Atlantic hurricane in 1999

Hurricane Dennis caused flooding in North Carolina and the Mid-Atlantic states in early September 1999, which would later be compounded by Hurricane Floyd. The fifth tropical cyclone of the season, Dennis developed from a tropical wave to the north of Puerto Rico on August 24. Originally a tropical depression, the system moved west-northwestward and strengthened into a tropical storm despite unfavorable wind shear. The storm became a hurricane by August 26. After striking the Abaco Islands, conditions improved, allowing for Dennis to strengthen into a Category 2 on the Saffir–Simpson scale by August 28. Around this time, Dennis began to move parallel to the Southeastern United States. Early on August 30, the storm peaked with winds of 105 mph (165 km/h). By the following day, steering currents collapsed and the storm interacted with a cold front, causing Dennis to move erratically offshore North Carolina. Wind shear and cold air associated with the front weakened Dennis to a tropical storm on September 1 and removed some of its tropical characteristics. Eventually, warmer ocean temperatures caused some re-strengthening. By September 4, Dennis turned northwestward and made landfall in Cape Lookout, North Carolina, as a strong tropical storm. The storm slowly weakened inland, before transitioning into an extratropical cyclone over western New York on September 7.

<span class="mw-page-title-main">Hurricane Emily (1993)</span> Atlantic hurricane in 1993

Hurricane Emily in 1993 caused record flooding in the Outer Banks of North Carolina while remaining just offshore. The fifth named storm and the first yet strongest hurricane of the year's hurricane season, Emily developed from a tropical wave northeast of the Lesser Antilles on August 22, 1993. It moved northwestward and strengthened into a tropical storm on August 25, after becoming nearly stationary southeast of Bermuda. Emily then curved to the southwest but quickly resumed its northwest trajectory while strengthening into a hurricane. Late on August 31, the hurricane reached peak winds of 115 mph (185 km/h) on its approach to North Carolina. Although part of the eye passed over Hatteras Island in the Outer Banks, its absolute center remained 23 mi (37 km)/h) offshore. Gradually weakening, the hurricane swerved away from the coast toward the northeast and later east. Emily stalled again, this time northeast of Bermuda, and dissipated on September 6 to the southeast of Newfoundland.

<span class="mw-page-title-main">North Carolina Highway 12</span> State highway in North Carolina, US

North Carolina Highway 12 (NC 12) is a 148.0-mile-long (238.2 km) primary state highway in the U.S. state of North Carolina, linking the peninsulas and islands of the northern Outer Banks. Most sections of NC 12 are two lanes wide, and there are also two North Carolina Ferry System routes which maintain continuity of the route as it traverses the Outer Banks region. NC 12 is part of the Outer Banks Scenic Byway, a National Scenic Byway. The first NC 12 appeared on the 1924 North Carolina Official Map and at its greatest length ran from NC 30 in Pollocksville to NC 48 near Murfreesboro. Over time it was replaced by both U.S. Route 258 (US 258) and NC 58 and ceased to exist in 1958. The current NC 12 first appeared on the 1964 state highway map running from US 158 in Nags Head to Ocracoke. In 1976 NC 12 was extended to US 70 on the mainland and in 1987 was extended north to Corolla.

<span class="mw-page-title-main">Effects of Hurricane Isabel in North Carolina</span>

The effects of Hurricane Isabel in North Carolina were widespread, with the heaviest damage in Dare County. The hurricane made landfall in the Outer Banks of North Carolina on September 18. There, storm surge flooding and strong winds damaged thousands of houses. The storm surge produced a 2,000 feet (610 m) wide inlet on Hatteras Island, isolating Hatteras by road for two months. Several locations along North Carolina Highway 12 were partially washed out or covered with debris. Hurricane Isabel produced hurricane-force wind gusts across eastern North Carolina, knocking down trees and power lines. About 700,000 residents lost power due to the storm, although most outages were restored within a few days. The hurricane killed three people in the state – two due to falling trees, and the other a utility worker attempting to restore electricity. Damage in the state totaled $450 million.

<span class="mw-page-title-main">Carova Beach, North Carolina</span>

Carova Beach or Carova is an unincorporated community in Currituck County in the extreme northeastern corner of North Carolina, United States. The community, begun in the 1960s, is found on Currituck Banks, north of Bodie Island, and can be accessed only by boat or by four-wheel drive vehicle. There are no paved roads connecting Carova to the town of Corolla, North Carolina. The neighboring settlement of Sandbridge in Virginia Beach, Virginia is not accessible by vehicle from Carova. In the 1960s, when development began in Carova, there were plans to construct a paved road from Sandbridge south to Carova through the Back Bay National Wildlife Refuge, but these never materialized. Today, there is a permanent fence from ocean to sound to keep vehicles from crossing and, more importantly, to keep the wild horses from migrating to the Virginia side of the border. To reach Carova, four-wheel drive vehicles must drive north along the beach from Corolla into the community, as access from Virginia is limited to pedestrians and bicyclists.

<span class="mw-page-title-main">Hurricane recovery in North Carolina</span> Dealing with effects of hurricanes in North Carolina

Due to the common occurrence of hurricanes in the coastal state of North Carolina, hurricane recovery in North Carolina is a large component of the state's emergency management efforts. Recovery from these tremendous storms at the local and state level is a large part of the aftermath of a hurricane. Gavin Smith and Victor Flatt stated that "Disaster recovery remains the least understood aspect of hazards management, when assessed relative to preparedness, response, and hazard mitigation." Smith and Flatt also went on to state that the role of the states is even less understood. The review of the plans and policies that instruct recovery, agencies involved, funding processes and budgets, and the environmental effects of a hurricane creates a better understanding of how North Carolina recovers from a hurricane.

<span class="mw-page-title-main">Coastal hazards</span>

Coastal hazards are physical phenomena that expose a coastal area to the risk of property damage, loss of life, and environmental degradation. Rapid-onset hazards last a few minutes to several days and encompass significant cyclones accompanied by high-speed winds, waves, and surges or tsunamis created by submarine (undersea) earthquakes and landslides. Slow-onset hazards, such as erosion and gradual inundation, develop incrementally over extended periods.

<span class="mw-page-title-main">Effects of Hurricane Isaac in Louisiana</span>

The effects of Hurricane Isaac in Louisiana were more severe than anywhere in the storm's path, and included $611.8615 million in damages and five total deaths. Forming from a tropical wave in the central Atlantic, Isaac traversed across many of the Lesser and Greater Antilles, before reaching peak intensity with winds of 80 mph (130 km/h) on August 28, 2012 while in the Gulf of Mexico. Nearing the coast of Louisiana, the Category 1 hurricane slowly moved towards the west, making two landfalls in the state with little change of intensity prior to moving inland for a final time. The hurricane weakened and later dissipated on September 1 while over Missouri. Before landfall, Governor Bobby Jindal declared a state of emergency to the state, as well as ordering the mandatory evacuation of 60,000 residents in low-lying areas of Louisiana along the Tangipahoa River in Tangipahoa Parish.

<span class="mw-page-title-main">New York Harbor Storm-Surge Barrier</span> Proposed barrier/floodgate system to protect New York metro area

The New York Harbor Storm-Surge Barrier was a proposed barrier and floodgate system to protect the New York-New Jersey Harbor Estuary from storm surges. The proposed system would consist of one barrier located across the mouth of Lower New York Bay between Sandy Hook (N.J.) and Rockaway (N.Y.) and a second on the upper East River to provide a ring of protection to most of the bi-state region. Through extensive use of floodgates, both barriers would have largely open cross-sections during normal conditions to minimize environmental impacts on the estuary and port operations. The plan was ultimately abandoned in 2020.

<span class="mw-page-title-main">Effects of Hurricane Dorian in the Carolinas</span>

Hurricane Dorian caused severe flooding and hurricane-force winds over parts of the coastal Carolinas during early September 2019. After stalling over The Bahamas for three days as a Category 5 hurricane, Dorian proceeded generally to the northwest, before moving along the Atlantic Coast, striking the town of Buxton, North Carolina, on September 6.

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