"Barrier islands" means elongated narrow landforms consisting largely of unconsolidated and shifting sand, fronted on one side by the ocean and on the other by a bay or marshland which separates them from the mainland.
"Dune crest" means the highest elevation of the coastal primary sand dune on the lot as determined in consultation with the Virginia Institute of Marine Science.
"Local 100-year long-term recession rate" means calculating the average shoreline recession over fixed one-mile intervals averaged over the period between surveys of 100 years or more.
Survival of these barrier islands often depends on the ability of sand to wash across the island naturally in concert with the local wind and wave climate. The sand is then protected from loss offshore and provides a means of perpetuating the island, albeit in a more landward location. Activities which adversely affect this interaction can have an extremely detrimental impact on the island as well as the structure, form and function of its dune system. The artificial accumulation of sand along the oceanside of an island can make it more susceptible to loss offshore during a storm. Once such a loss occurs, the sand then becomes unavailable for washover and for the continued landward migration of the island. Houses, sand fences and similar structures can also alter wind patterns; this alteration impedes the wind transport of sand across the island. Accumulations adjacent to these impediments can be lost offshore as the shoreline continues to recede, leading to an increased rate of recession and a narrowing of the island. In addition, many of the Commonwealth's rarest species depend on the continuation of natural processes that currently exist on barrier islands. Consequently they are threatened by any interference with those processes. The implementation of the policies and guidelines set forth in this chapter will support a fuller achievement of the purposes of the Virginia Natural Area Preserves Act (§ 10.1-209 et seq. of the Code of Virginia), the Virginia Endangered Species Act (§ 29.1-563 et seq. of the Code of Virginia) and the Virginia Endangered Plant and Insect Species Act (§ 3.1-1020 et seq. of the Code of Virginia).
Two of the main natural features of barrier islands are natural dunes and washover areas, both of which are included in the statutory definition of a coastal primary sand dune as a "mound of unconsolidated sandy soil which is contiguous to mean high water, whose landward and lateral limits are marked by a change in grade from 10% or greater to less than 10% and upon any part of which is growing" certain designated plants as listed in § 62.1- 13.22 of the Code of Virginia. Given the particular combination of risks to both natural values and life and property posed by development on barrier islands, the commission finds it necessary and appropriate to establish a policy and supplemental guidelines to assist landowners and decision makers alike in shaping barrier island uses in a manner that preserves and protects the values of coastal primary sand dunes as set forth by the General Assembly.
4 Va. Admin. Code § 20-440-10
Statutory Authority
§28.2-103 and Chapter 14 ( § 28.2-1400 et seq.) of Title 28.2 of the Code of Virginia.