Section 2: Areas of Environmental Concern
Areas of Environmental Concern (AECs) are the foundation of the Coastal Resources Commission's permitting program for coastal development. An AEC is an area of natural importance: It may be easily destroyed by erosion or flooding; or it may have environmental, social, economic or aesthetic values that make it valuable to our state.
The Coastal Resources Commission designates areas as AECs to protect them from uncontrolled development, which may cause irreversible damage to property, public health or the environment, thereby diminishing their value to the entire state. The CRC has set up four categories of AECs:
The Estuarine and Ocean System
The Ocean Hazard System
Public Water Supplies
Natural and Cultural Resource Areas
AECs cover almost all coastal waters and less than 3 percent of the land in the 20 coastal counties. The following descriptions will help you determine if your project is in an AEC and will help you understand the importance of these natural systems.
A. The Estuarine and Ocean System AEC
The estuarine and ocean system is the coast's broad network of brackish sounds, marshes and surrounding shores. Normally found where rivers and streams meet the ocean, an estuary is a unique and important part of coastal life – a transitional area where fresh and salt water mix. From broad, shallow sounds like the Albemarle and Pamlico, to narrow bodies of water such as Core and Masonboro sounds, North Carolina has 2.2 million acres of estuarine waters. Cradled behind the state's long string of barrier islands, these shallow sounds, rivers and creeks make up one of the largest estuarine systems in the United States. Permits may be required for development in four components of this system (see Figure 2.1).
1. Public Trust Areas are the coastal waters and submerged lands that every North Carolinian has the right to use for activities such as boating, swimming or fishing. These areas often overlap with estuarine waters, but they also include many inland fishing waters. The following lands and waters are considered public trust areas:
all waters of the Atlantic Ocean and the lands underneath, from the normal high water mark on shore to the state's official boundary three miles offshore;
all navigable natural water bodies and the lands underneath, to the normal high watermark on shore (a body of water is considered navigable if you can float a canoe in it). This does not include privately owned lakes where the public doesn't have access rights;
all water in artificially created water bodies that have significant public fishing resources and are accessible to the public from other waters; and
all waters in artificially created water bodies where the public has acquired rights by prescription, custom, usage, dedication or any other means.
2. Estuarine Waters are the state's oceans, sounds, tidal rivers and their tributaries, which stretch across coastal North Carolina and link to the other parts of the estuarine system: public trust areas, coastal wetlands and coastal shorelines.
For regulatory purposes, the inland, or upstream, boundary of estuarine waters is the same line used to separate the jurisdictions of the Division of Marine Fisheries and the Wildlife Resources Commission. However, many of the fish and shellfish that spend parts of their lives in estuaries move between the "official" estuarine and inland waters.
3. Coastal Shorelines include all lands within 75 feet of the normal high water level of estuarine waters. This definition also includes lands within 30 feet of the normal high water level of public trust waters located inland of the dividing line between coastal fishing waters and inland fishing waters. Along Outstanding Resource Waters, this definition includes lands within 575 feet of the normal high water level.
4. The Coastal Resources Commission's rules define Coastal Wetlands as any marsh in the 20 coastal counties that regularly or occasionally floods by lunar or wind tides, and that includes one or more of 10 plant species (see Figure 2.2)
Spartina alterniflora: Salt Marsh (Smooth) Cord Grass
Juncus roemerianus: Black Needlerush
Salicornia spp.: Glasswort
Distichlis spicata: Salt (or Spike) Grass
Limonium spp.: Sea Lavender
Scirpus spp.: Bulrush
Cladium jamaicense: Saw Grass
Typha spp.: Cattail
Spartina patens: Salt Meadow Grass
Spartina cynosuroides: Salt Reed or Giant Cord Grass
Note: Freshwater swamps and inland, non-tidal wetlands are not in the CAMA permit jurisdiction, unless the CRC specifically designates them as AECs. However, these wetlands are protected by the federal Clean Water Act. An Army Corps of Engineers permit may be required for projects taking place in these wetlands.
Learn More: Why we should protect the estuarine and ocean system
The lands and waters of the estuarine system are home to fish nursery areas, spawning areas, shellfish beds and other habitats essential to North Carolina's commercial and recreational fishing industries.
More than 90 percent of North Carolina's commercial and recreational seafood species (such as shrimp, flounder and crabs) depend on the protective habitat and nutrients found in coastal wetlands and estuarine waters for much of their lives.1
The stems, roots and seeds of many coastal wetland plants provide food and nesting materials for waterfowl and other wildlife.
Marsh plants guard against erosion and flood damage: Their leaves and stems dissipate wave energy, and their root systems bind soil. The nutrients and decayed plant material the marsh plants produce also contribute to the productivity of the estuarine system.
Estuarine plants trap debris and excess nutrients and help regulate the flow of fresh water into the estuary, maintaining the system's balance.
Estuarine shorelines act as natural barriers to erosion and flooding. Certain soil formations and plant communities along estuarine shorelines also help slow erosion.
Natural buffers along the shoreline protect the water from excess sediment and pollutants, and they protect nearby developments from flooding and erosion.
Estuarine waters and public trust areas are important for tourism, because they support commercial and recreational fishing, boating, swimming and other recreational activities.
1 NC Division of Marine Fisheries, 1999
B. The Ocean Hazard System AEC
One of the most notable aspects of North Carolina's coast is the band of narrow barrier islands piecing together the state's eastern border. Many of these islands are home to thriving communities, such as the Outer Banks or the towns of Wrightsville Beach, Carolina Beach and Atlantic Beach. Others, such as Masonboro Island, remain largely untouched by development.
All barrier islands change constantly under the forces of wind and water. These forces create a variety of hazards – such as storms, flooding and dune erosion – that can threaten buildings and other structures located there.
The Ocean Hazard System is made up of oceanfront lands and the inlets that connect the ocean to the sounds. The Coastal Resources Commission has designated three ocean hazard AECs (see Figure 2.3).
1. The Ocean Erodible AEC covers North Carolina's beaches and any other oceanfront lands that are subject to long-term erosion and significant shoreline changes. The seaward boundary of this AEC is the mean low water line.
The landward limit of the AEC is measured from the first line of stable natural vegetation and is determined by adding:
a distance equal to 60 times the long-term, average annual erosion rate for that stretch of shoreline to
the distance of erosion expected during a major storm.
The width of the AEC varies from about 145 feet to more than 700 feet.
The CRC updates long-term erosion rates about every five years, using aerial photographs to examine shoreline changes. General maps of erosion rates are available free from the Division of Coastal Management; detailed erosion rate maps are available for inspection at all Coastal Management field and local permitting offices.
2. The High Hazard Flood AEC covers lands subject to flooding, high waves and heavy water currents during a major storm. These are the lands identified as coastal flood with velocity hazard, or "V zones," on flood insurance rate maps prepared by the Federal Insurance Administration. "V zones" are determined by an engineering analysis of expected flood levels during a storm, expected wave and current patterns, and the existing topography of the land. The high hazard flood AEC often overlaps with the ocean erodible and inlet hazard AECs.
3. The Inlet Hazard AEC covers the lands next to ocean inlets. Inlet shorelines are especially vulnerable to erosion and flooding and can shift suddenly and dramatically. For each inlet along the coast, the Division of Coastal Management prepares a hazard area map that is reviewed and approved by the Coastal Resources Commission. Each area is mapped based on a statistical analysis of inlet migration, previous inlet locations, narrow or low lands near the inlet, and the influence of man-made features, such as jetties and channelization projects.
In each case, the distance the inlet hazard AEC extends inland is estimated to be large enough to encompass those lands where the inlet can be expected to migrate. At a minimum, this distance is the same distance inland as the ocean erodible AEC. Inlet hazard AECs range in width from about 250 feet for a fairly stable inlet to about 4,000 feet for the most dynamic inlets.
Learn More: Why we should protect ocean hazard areas
At the edge of the ocean, ocean hazard AECs get the full force of any storm. Waves, wind and water can quickly change the shape of a shoreline, creating or filling inlets, flattening nearby dunes, eroding beaches and battering nearby structures. No oceanfront development can be absolutely safe from destructive natural forces, but development in ocean hazard areas can be carefully designed and located to minimize the risk to life and property, as well as to reduce the cost of relief aid.
Oceanfront beaches and dunes help protect buildings and environments behind them by absorbing the force of wind and waves, while the dense root networks of dune plants trap and anchor sand. Left uncontrolled, development can destroy these dunes and their vegetation, increasing the risk of damage to structures from erosion, flooding and waves.
C. Public Water Supply AECs
We need fresh water for many aspects of life – drinking, farming, industry – and the protection of these waters is vital to our health and our economy.
As rain runs off pavement and rooftops, it carries pollutants and sediments that can put our waters at risk. The CRC has designated two AECs that protect certain coastal public water supplies from the negative effects of development.
1. The Small Surface Water Supply Watershed AEC protects coastal drainage basins that contain a public water supply classified as A-II by the N.C. Environmental Management Commission. This classification means that the best use of the water is for public drinking water, and this use must be protected by state regulations. To date, two such watersheds have been designated as AECs: the Fresh Pond at the Nags Head and Kill Devil Hills border; and Toomer's Creek near Wilmington.
2. Public Water Supply Wellfields are areas of rapidly draining sands extending from the earth's surface to a shallow groundwater table that supplies public drinking water. Currently, one wellfield is designated as an AEC, on Hatteras Island at Buxton.
Learn More: Why we should protect public water supply AECs
Development is rarely proposed in these surface watersheds and wellfields, which are almost entirely in public ownership. But if degraded, these water supplies could threaten public health or force local communities to spend a lot of money to develop alternative water sources. Uncontrolled development within these areas can change runoff patterns or groundwater withdrawal rates, and reduce both the quantity and quality of the raw water supply. Sediment from construction sites and a variety of pollutants from buildings, parking lots and roads also can damage our waters.
D. Natural and Cultural Resource AECs
Natural and cultural resource AECs are specific sites designated to receive protection because they contain environmental or cultural resources that are important to the entire state. They may be important because of their role in maintaining the coastal ecosystem, resources for scientific research and education, historical significance, or aesthetic value. Any person can nominate an area as a natural or cultural resource AEC; the CRC makes the final decision on designation.
There are four types of natural and cultural resource AECs.
1. Coastal complex natural areas are lands that support native plants and animal communities, providing habitats essentially unchanged by human activity. These areas are key components of natural biological systems. They provide us with a historical perspective against which to measure the change in coastal habitats; they are a valuable scenic or cultural resource; and they provide an irreplaceable scientific and educational resource. You may be allowed to develop these areas if the development benefits the habitat or enhances the area's biological, scientific or educational values.
2. Coastal areas that sustain remnant species provide habitat for native plant or animal species that the N.C. Wildlife Resources Commission or the federal government has determined to be rare, threatened or endangered. Such areas are necessary for the survival of these species within the coastal region and for maintaining the coast's natural diversity. These areas also provide a valuable educational and scientific resource that cannot be duplicated or replaced.
3. Unique coastal geologic formations are areas containing especially notable examples of geologic formations or processes found in the coastal area. Such formations are important educational, scientific and scenic resources. Jockey's Ridge in Dare County has been designated because of its unique geologic features.
4. Significant coastal archaeological resources and significant coastal historical archeological resources contain objects, features, buildings or sites that:
yield information important to the state's or the coastal region's history;
are associated with events that have contributed to the broad patterns of history;
are associated with the lives of historically important people; or
embody the distinctive characteristics of a type, period or method of construction.
These areas provide unmatched and irreplaceable scientific, educational and aesthetic resources that commemorate the coastal region's heritage. Permuda Island, located in Onslow County, has been protected for its outstanding archeological resources.