Land Planning
Land planning is designing your property around existing conditions and possible erosion.  This includes utilizing the land as it exists without construction of shoreline stabilization methods.   The most common practices associated with land planning include setbacks, buffers, and no action.   Land Planning allows for marsh to migrate and allows for the system to remain natural at minimal cost, but will allow erosion to continue. 

Permitting Options:  None required

Vegetation Control
Vegetation control (a.k.a.: Wetland or upland plantings) is the use of wetland (marsh or swamp forest) vegetation (new plantings or preserving existing wetland vegetation) to control or prevent further erosion.  Vegetation may be planted or allowed to colonize naturally.  A final established minimum width of 10 feet is preferable to dissipate wave energy and thus controlling erosion.  Planting vegetation is the cheapest and most environmentally sound stabilization method.  Vegetation increases the marsh habitat and provides food for the lower organisms such as algae and seaweeds, finfish and shellfish, mammals and shorebirds.

Construction Material Options:  Wetland or Upland Vegetation native to the area. 

Permitting Options:  None required unless filling and/or grading is needed. 

Marsh Toe Protection Revetments
Marsh Toe Protection Revetments (a.k.a.: Riprap at the waterward toe of marsh) are a shore-parallel, sloping structure constructed against a marsh escarpment to protect the marsh wetland roots from undermining.  Placing riprap or stone on the waterward edge of the marsh helps to stabilize or reestablish the marsh vegetation.  Marsh grasses dissipate wave energy and wave height through friction and drag, and thus help to reduce erosion further inland (usually on the high ground).  Marsh vegetation also increases the marsh habitat and provides food for the lower organisms such as algae and seaweeds, finfish and shellfish, mammals and shorebirds.

Construction Material Options:  Stone/Riprap

Permitting Options:  General or Major Permit

Sills A sill (a.k.a.: Marsh Sills, Marsh Enhancement Breakwaters) is a shore-parallel, wood orrock structure that is designed to protect existing or newly planted wetland vegetation. A sill is placed just offshore of existing marsh to help reduce the erosion of the waterward edge (escarpment).  If there is not marsh already on the property, a sill is placed just offshore of where marsh would or could grow and is planted.  The sill helps to protect the marsh by dissipated enough wave energy so that the marsh can establish.  Once established, the marsh grasses dissipate wave energy and wave height through friction and drag, and thus help to reduce erosion further inland (usually on the high ground).  Marsh vegetation also increases the marsh habitat and provides food for the lower organisms such as algae and seaweeds, finfish and shellfish, mammals and shorebirds.
Stone Sill:
Sheet Pile Sill:

Construction Material Options:  Stone/Riprap, Timber, Vinyl

Permitting Options:  General or Major Permit

Groins
A groin is a straight and usually shore-perpendicular structure, constructed with stone or as a freestanding vertical wall to trap sand along one side.  Trapped sand becomes a wave energy dissipation zone during daily wave action or sacrificial buffer during storms.  Groins can be constructed either singly or in a series.  Groins function only when longshore transport of sand (movement of sand along a shoreline) occurs and thus traps sand.  Groins produce accretion of beach material along the updrift side and erosion on the downdrift side. 

A saw-toothed shaped shoreline is created with a series of groins. The trapped sand is commonly “stolen” from somewhere downdrift, which then in turn accelerates erosion downdrift of your property.  Groins are often mistakenly called jetties, which are larger structures designed for stabilization of navigation channels at river mouths and tidal inlets.

Construction Material Options:  Stone/Riprap, Timber, Vinyl, Concrete

Permitting Options:  General or Major Permit

Breakwaters
A breakwater (a.k.a.: Wave Attenuator, Wave Breaks, Wave Fence) is a shore-parallel non-shore-connected structure, designed to trap sand and to attenuate wave energy.  Breakwaters are typically constructed of stone, with multiple structures detached or gapped with a distance equal to length of one individual structure. Breakwaters reflect and dissipate wave energy creating a lower wave energy area landward of the structure.  A sandy beach is usually created between the structure and shore, but only when longshore transport of sand (movement of sand along a shoreline) occurs. The trapped sand is commonly “stolen” from somewhere downdrift, which then in turn accelerates erosion downdrift of your property. 

Construction Material Options:  Stone/Riprap, Timber, Vinyl, Concrete

Permitting Options:  Major Permit Only

Riprap Revetments
A revetment (a.k.a.: Riprap, Sloped Structure) is a shore-parallel, sloping structure constructed against a bank/escarpment to protect it from erosion while absorbing wave energy.  Revetments are typically constructed on a 1V: 1.5-3H slope.  The riprap used to construct the revetment will settle and readjust during storms or wave action and as such the stone used needs to be heavy enough or securely tied down to remain in place.  Revetments are long lasting structures designed to hold back the land to prevent erosion and because it is sloped, absorb wave action.  Although revetments cause a loss of soft bottom habitat, it causes less habitat destruction and loss than bulkheads and also creates fisheries habitat. 

Construction Material Options:  Stone/Riprap, Concrete

Permitting Options:  General or Major Permit

Bulkheads
A bulkhead (a.k.a.: Vertical Structure, Seawall, Gravity Wall) is any shore-parallel vertical structure designed to prevent overtopping, flooding, or sliding of the land.  Bulkheads are usually placed along an eroding bank or escapement to hold back the land and prevent erosion.  Bulkheads are a long lasting hardy structure that can stand up to moderate to high wave energy; but they also prevent the natural migration of wetland vegetation. 

Construction Material Options:  Timber, Steel, Vinyl, Concrete

Permitting Options:  General or Major Permit

For further information or questions please contact DCM’s Coastal Engineer, Bonnie Bendell at 919-733-2293 ext 256, Bonnie.Bendell@ncmail.net or 1638 Mail Service Center, Raleigh, NC 27699-1638.