7.3 Coastal Boundaries, Mean High Water Mark & Coastal Area Management Act (CAMA)

7.3 Coastal Boundaries, Mean High Water Mark & Coastal Area Management Act (CAMA)

Coastal surveying in North Carolina requires the Professional Land Surveyor to master the intersection of astronomical tidal datums, statutory property boundaries, and complex environmental regulations. North Carolina's 300-plus miles of ocean coastline and thousands of miles of estuarine shorelines are governed by specific statutory definitions under G.S. Chapter 77 (Rivers, Creeks, and Coastal Waters), administrative rules under 15A NCAC 07H, and the Coastal Area Management Act of 1974 (CAMA, G.S. 113A-100 et seq.).

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|                 NORTH CAROLINA OCEAN COASTAL PROFILE & BOUNDARY ZONES       |
|                                                                             |
|   ATLANTIC OCEAN       WET SAND FORESHORE     DRY SAND BEACH      UPLAND    |
|   ~~~~~~~~~~~~~~~~    ~~~~~~~~~~~~~~~~~~~   ──────────────────  ─────────── |
|   (Submerged Bed)      (Public Trust Bed)   (Public Easement)   (Private)   |
|                        ▲                    ▲                   ▲           |
|                        │                    │                   │           |
|                       MLWM                 MHWM               FLSNV         |
|                   (Mean Low Water)   (Mean High Water)   (First Line of     |
|                                      [PRIVATE SEAWARD     Stable Natural    |
|                                       PROPERTY LINE]      Vegetation)       |
|                                      <G.S. 77-20(a)>     [CAMA SETBACK BASE]|
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1. The Seaward Boundary: Mean High Water Mark (G.S. 77-20)

In North Carolina, the boundary between state-owned sovereign foreshore and private upland oceanfront property is established by statute and landmark Supreme Court decisions (Carolina Beach Fishing Pier, Inc. v. Town of Carolina Beach, 277 N.C. 297, 177 S.E.2d 513 (1970); Gwathmey v. State, 342 N.C. 287 (1995)).

The Statutory Mandate of G.S. 77-20(a):

"The seaward boundary of all property within the State of North Carolina, not owned by the United States, which lies on the Atlantic Ocean, is the mean high water mark."

Astronomical Basis: The 19-Year Tidal Datum Epoch (NTDE)

The Mean High Water Mark (MHWM) is not a visual guess or a single water mark left by a high tide. In surveying and hydrographic law (Borax Consolidated, Ltd. v. City of Los Angeles, 296 U.S. 10 (1935); Carolina Beach Fishing Pier), MHW is defined as:

• The arithmetic mean of all the high water heights observed over a 19-year National Tidal Datum Epoch (NTDE).
• The 19-year period is necessary to account for the 18.6-year astronomical lunar nodal cycle (the regression of the moon's nodes across the ecliptic plane), which causes systematic cyclic variations in tidal amplitudes, as well as annual meteorological variations.
• The current official National Tidal Datum Epoch administered by NOAA's National Ocean Service (NOS) is the 1983–2001 epoch.

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|                     COASTAL DATUM PLANE INTERSECTION                        |
|                                                                             |
|   ELEVATION (NAVD88)                                                        |
|   ▲                                                                         |
|   │              MHW Elevation Plane (e.g., +1.82 ft NAVD88)                |
|   ├─────────────────────────────────────────────● [MEAN HIGH WATER MARK]    |
|   │                                            /  (Intersection with        |
|   │                                           /    Physical Beach Surface)  |
|   │                                          /                              |
|   │              MLW Elevation Plane        /                               |
|   ├────────────────────────────────────────● [MEAN LOW WATER MARK]          |
|   │                                       /                                 |
|   └──────────────────────────────────────┴───────────────────────────────►  |
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Legal Classification of the Coastal Zones:

1. Submerged Ocean Bottom (Seaward of MLWM): Owned in fee simple by the State of North Carolina in sovereign public trust out to the 3-nautical-mile territorial sea limit.
2. Foreshore / Wet Sand Beach (Between MLWM and MHWM): The strip of beach alternately covered and uncovered by the daily ebb and flow of normal tides. Owned in fee simple by the State of North Carolina in sovereign public trust for public passage, fishing, and navigation (Carolina Beach Fishing Pier).
3. Dry Sand Beach (Between MHWM and FLSNV): The area between the Mean High Water Mark and the first line of stable natural vegetation. Title may be held by the private littoral owner, but is encumbered by the Public Beach Trust Area under G.S. 77-20(e).
4. Upland Dunes & Structures (Landward of FLSNV): Private fee simple property subject to CAMA environmental setbacks and local zoning.

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2. The Public Dry Sand Beach Trust Area (G.S. 77-20(e))

Under North Carolina common law and G.S. 77-20(d)-(e), the public's right to use the ocean beaches is protected under the Public Trust Doctrine:

"The public having made frequent, uninterrupted, and customary use of the ocean beaches throughout North Carolina since time immemorial... the public trust rights shall encompass the entire dry sand beach between the mean high water line and the first line of stable, natural vegetation."

Customary Use and Municipal Authority

In Nies v. Town of Emerald Isle, 244 N.C. App. 81, 780 S.E.2d 187 (2015), private beachfront property owners challenged a town ordinance permitting municipal emergency and patrol vehicles to drive on the dry sand beach, claiming it was an unconstitutional taking of private property. The North Carolina Court of Appeals held that:

• The dry sand beach from the MHWM to the vegetation line is burdened with public trust rights under state common law and G.S. 77-20(e).
• Littoral property owners hold dry sand beach subject to the superior public easement for customary recreational use and governmental safety oversight.
• Municipal regulations protecting public beach access do not constitute a compensable taking of private property.

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3. The Coastal Area Management Act (CAMA) & Areas of Environmental Concern

Enacted in 1974, the Coastal Area Management Act (CAMA, G.S. 113A-100 et seq.) establishes a comprehensive cooperative management program between state and local governments across North Carolina's 20 coastal counties (Beaufort, Bertie, Brunswick, Camden, Carteret, Chowan, Craven, Currituck, Dare, Gates, Hertford, Hyde, New Hanover, Onslow, Pamlico, Pasquotank, Pender, Perquimans, Tyrrell, and Washington).

CAMA is administered by the Coastal Resources Commission (CRC) and enforced by the Division of Coastal Management (DCM) within the North Carolina Department of Environmental Quality (NC DEQ).

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|                   THE FOUR STATUTORY CAMA AEC CATEGORIES                    |
|                                                                             |
|   1. THE ESTUARINE AND OCEAN SYSTEM (15A NCAC 07H .0200)                    |
|      * Estuarine Waters (Sounds, tidal rivers, coastal bays)                |
|      * Coastal Wetlands (Tidal salt marshes, brackish marshes)              |
|      * Public Trust Areas (Navigable water bodies and shorelines)           |
|      * Estuarine Shorelines (75-foot buffer landward of coastal wetlands)   |
|                                                                             |
|   2. THE OCEAN HAZARD SYSTEM (15A NCAC 07H .0300)                           |
|      * Ocean Erodible Areas (Subject to high shoreline recession)           |
|      * High Hazard Flood Areas (V-Zones subject to storm wave action)       |
|      * Inlet Hazard Areas (Dynamic shorelines adjacent to ocean inlets)     |
|      * Unvegetated Beach Areas (Dynamic overwash sand bars)                 |
|                                                                             |
|   3. PUBLIC WATER SUPPLIES (15A NCAC 07H .0400)                             |
|      * Small surface water supply watersheds and coastal aquifer fields     |
|                                                                             |
|   4. NATURAL AND CULTURAL RESOURCE AREAS (15A NCAC 07H .0500)               |
|      * Coastal complex natural areas, unique coastal features, historic sites|
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4. Ocean Hazard Setback Rules & Vegetation Line Surveys

For any proposed construction or development within the Ocean Hazard AEC, a Professional Land Surveyor must locate the physical baseline from which mandatory state development setbacks are measured.

The First Line of Stable and Natural Vegetation (FLSNV)

Under 15A NCAC 07H .0305, the regulatory baseline for ocean hazard setbacks is the First Line of Stable and Natural Vegetation (FLSNV):

• The FLSNV is defined as the physical connection between the bare dry sand beach and the permanent natural beach grasses (e.g., sea oats, American beachgrass, bitter panicum).
• The vegetation must be natural, self-sustaining, and mature; newly planted or seasonal vegetation that has not established root systems cannot be used as the FLSNV.
• The surveyor must locate the actual FLSNV in the field using GPS or conventional surveying methods.

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|                CAMA OCEAN HAZARD SETBACK CALCULATION FORMULA                |
|                                                                             |
|   [MINIMUM SETBACK (Structure <= 5,000 sq ft)]                              |
|   Setback Distance = 30 x Annual Erosion Rate (Minimum 60 Feet)             |
|   (e.g., if Erosion Rate is 2.0 ft/yr --> Setback = 30 x 2.0 = 60 ft)       |
|   (e.g., if Erosion Rate is 3.5 ft/yr --> Setback = 30 x 3.5 = 105 ft)      |
|                                                                             |
|   [GRADUATED SETBACKS FOR LARGER STRUCTURES (15A NCAC 07H .0306)]           |
|   * 5,000 to 9,999 sq ft:   60 x Annual Erosion Rate (Min 120 ft)           |
|   * 10,000 to 49,999 sq ft: 65x to 85x Annual Erosion Rate                  |
|   * 50,000 to 99,999 sq ft: 90x Annual Erosion Rate                         |
|   * 100,000+ sq ft:         105x Annual Erosion Rate                        |
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Static Vegetation Lines vs. Development Lines (15A NCAC 07H .0305)

When a municipality or federal agency performs a large-scale beach nourishment or dune reconstruction project (placing millions of cubic yards of sand on the beach):

1. The Static Vegetation Line: Placing artificial sand pushes the temporary physical vegetation line far seaward. To prevent unsafe construction on temporary artificial fill, CAMA establishes a Static Vegetation Line (the FLSNV surveyed immediately prior to the start of the nourishment project). All future building setbacks must continue to be measured from this permanent Static Line, regardless of where new beach grass grows.
2. Static Line Exception / Development Line: If a coastal community develops an approved 30-year beach management plan with dedicated local funding for recurring maintenance, the town may petition the CRC for a Static Line Exception or establish an approved Development Line, allowing setbacks to be measured from a newly designated line seaward of the historic static line.

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5. PLS Coastal Survey Protocols & Certified Plat Requirements

Under 21 NCAC 56.1600 and CAMA permit guidelines, a coastal boundary survey plat must include:

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|                     PLS COASTAL BOUNDARY PLAT REQUIREMENTS                  |
|                                                                             |
|   1. LOCATE ALL COASTAL FEATURES                                            |
|      * Mean High Water Mark (MHWM) with elevation & tidal epoch noted.      |
|      * First Line of Stable and Natural Vegetation (FLSNV) with date.       |
|      * Static Vegetation Line or Development Line (if applicable).          |
|      * Crest and toe of frontal dune and primary dune systems.              |
|      * Wet sand foreshore boundary and CAMA Setback lines.                  |
|                                                                             |
|   2. CALCULATE APPLICABLE SETBACK DISTANCES                                 |
|      * State the published DCM annual erosion rate for the lot frontage.    |
|      * Show the calculated CAMA setback line with perpendicular offsets.    |
|                                                                             |
|   3. MANDATORY CERTIFICATION NOTE                                           |
|      * "I certify that the First Line of Stable Natural Vegetation shown     |
|         hereon was located under my direct supervision on [Date] in         |
|         accordance with 15A NCAC 07H .0305 and G.S. 113A-100 et seq."       |
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[!WARNING] Dynamic Nature of Coastal Features: Because ocean shorelines erode rapidly during nor'easters and hurricanes, CAMA regulations specify that an FLSNV survey is valid for permitting only for a limited timeframe (typically within one year of permit application). If a storm damages the vegetation line prior to construction, a new field survey by a PLS is legally required.