Donna A. Milligan

An integrated habitat enhancement approach to shoreline stabilization for a Chesapeake Bay island community

Shore protection and habitat enhancement along a residential island werethe main goals of this shoreline study. The physical and geological factorsnecessary to design shoreline stabilization structures capable of confidentlysupporting suitable and stable habitat enhancement/restoration substrate areemphasized since this area of study generally may be unfamiliar to wetlandresource managers. Erosion along the targeted shoreline is influenced by aunidirectional wave field from the south-southwest. Results of our analysesshowthat a headland control system comprised of headland breakwaters could be usedsuccessfully to stabilize the existing shoreline and provide resource managersflexibility in habitat restoration decisions. Headland breakwaters are designedto diffract wave energy so that shore planform equilibrium is attained and canbe sized and positioned to maximize the length of stabilized shoreline.Maximization of the new shoreline length provides increased subaerial,intertidal, and subaqueous environments for flexible habitat restorationalternatives. The final restoration design developed through this study willcreate approximately 69,000 m2 of new habitat includingstable beach, dune, tidal marsh, scrub shrub, and submersed aquatic vegetation.An additional 2,000 m2 of rock substrate habitat isprovided directly by the headland control structures.

Classification of fetch limited dunes in the lower Chesapeake Bay: evidence of morphologic equilibrium.

Abstract As part of a comprehensive assessment of dunes and beaches in the Virginia portion of the Chesapeake Bay, U.S.A., we developed a classification system for dunes that incorporates historical shoreline dynamics, shoreline reach setting, local geomorphologic situation, and shoreline use. Our classification system demonstrates the broad diversity of sandy shorelines in the lower Bay; however, we present a geomorphologic relationship between dunes and beaches that appears to act independently of geologic diversity. Cross-shore profiles revealed that the height of the primary dune crest above mean low water relates to the lateral distance between the point of mean low water and the normal line through the dune crest (termed the estuarine dune index [EDI]) in a 1 : 10 ratio. Mean EDIs showed no statistically significant differences between shoreline classes, which provides firm evidence of an equilibrium condition for fetch limited dunes (termed the point-one rule) and promises to be useful for shoreline assessments and the sustainable engineering of nourished shorelines.

Mathews County Shoreline Management Plan

National Fish and Wildlife Foundation through Grant Number 2007-0081-014 Virginia Institute of Marine Science College of William & Mary

Living Shoreline Design Guidelines for Shore Protection in Virginia’s Estuarine Environments

Virginia Coastal Zone Management Program at the Department of Environmental Quality National Oceanic and Atmospheric Administration U.S. Department of Commerce