Description

A. What are Living Shorelines?

Coastal erosion near historic St. Mary’s City, Maryland. Photo: Rich Takacs, NOAA Restoration Center Coastal erosion near Grasonville, Maryland. Photo taken prior to Living Shoreline stabilization. Photo: Rich Takacs, NOAA Restoration Center Living Shoreline stabilization and fringe marsh establishment. Photo: Rich Takacs, NOAA Restoration Center Soft/nonstructural Living Shoreline stabilization with bio-log and natural vegetation. Photo: Rich Takacs, NOAA Restoration Center Hybrid Living Shoreline stabilization with bio-log, natural vegetation, and rock footer. Photo: Chesapeake Bay Foundation Habitat creation with soft/nonstructural Living Shoreline stabilization. Photo: Rich Takacs, NOAA Restoration Center

Shorelines have often been stabilized with hardened structures, such as bulkheads, stone revetments, and seawalls to prevent or minimize coastal erosion in riverine, estuarine, and marine environments. Ironically, hardened structures often increase the rate of coastal erosion, remove the ability of the shoreline to carry out natural processes, and provide little habitat for estuarine species. However, alternatives to hard/structural stabilization are available that use a natural “Living Shorelines” approach.

Living Shorelines utilize a suite of bank stabilization and habitat restoration techniques to reinforce the shoreline, minimize coastal erosion, and maintain coastal processes while protecting, restoring, enhancing, and creating natural habitat for NOAA trust resources. This technique was coined with the term “Living Shorelines” because it provides “living space” for riverine, estuarine, and coastal organisms, which is accomplished via the strategic placement of native vegetation, sand fill, organic materials, and, if necessary, a small amount of reinforcing rock seeded with oysters.

This natural bank stabilization approach can be utilized in low- to medium-energy coastal and estuarine environments, as well as in tidally influenced creeks, streams, and rivers. Living Shoreline stabilization is implemented via two methods: (1) soft/nonstructural stabilization that utilizes natural, nonstructural, and biodegradable materials; and (2) hybrid stabilization that utilizes a combination of soft/nonstructural and hard/structural materials. The use of soft/nonstructural materials as opposed to hybrid materials at a particular site can be determined via an analysis of the nature of the erosion problem, site characteristics (including location, elevation, wave energy, fetch, frequency of storms, prevailing wind and wave direction, presence of vegetation, runoff, and recreational use), costs and availability of building materials, and construction alternatives available.

Soft/Nonstructural Stabilization

Soft/nonstructural stabilization is typically implemented in low-energy creek, tributary, riverine, and estuarine environments to restore habitat without the use of hard structures. Materials used for soft/nonstructural stabilization include natural vegetation, submerged aquatic vegetation (SAV), sand fill, and biodegradable organic materials such as natural fiber logs (bio-logs) and organic matting. Soft/nonstructural stabilization creates a natural buffer to protect the shoreline from erosion; traps sediment and allows for increased vegetation; preserves or creates habitat for benthic, estuarine, shallow water, and intertidal organisms; and maintains natural habitat features and shoreline dynamics.

Hybrid Stabilization

Hybrid stabilization is typically implemented in medium-energy riverine, estuarine, and coastal environments to restore habitat with the assistance of some hardened structures. This method of stabilization involves the use of a minimal amount of rock to anchor soft/nonstructural materials in place, thus ensuring that project goals are met and habitat is restored for aquatic organisms. Hybrid materials include natural vegetation, SAV, sand fill, biodegradable organic materials, and low-profile rock structures such as segmented sills, stone containment groins, and living breakwaters seeded with oyster spat. Hybrid stabilization restores and protects shoreline habitat, maintains natural sand movement and tidal water exchange, and facilitates the movement of estuarine species into critical wetland habitat. Living Shorelines projects do not include projects that only use hard/structural stabilization methods.

B. Benefits of Living Shorelines

Living Shorelines provide the following benefits to both property owners and to flora and fauna in riverine, estuarine, and coastal ecosystems:

• Preserves, creates, or maintains habitat for aquatic flora and fauna.
• Restores critical feeding and nursery habitat for adult and juvenile fish.
• Provides wildlife access to the shoreline for nesting species of birds and terrapins.
• Maintains natural shoreline dynamics.
• Creates a natural buffer that absorbs wave energy and reduces coastal erosion.
• Traps and retains land runoff containing nutrients and pollutants.
• Can be used in a variety of low- to medium-energy environments, including bays, estuaries, lagoons, sheltered shorelines, and tidally influenced streams and rivers.
• Can be less costly than structural stabilization (e.g., bulkheads and seawalls) when implemented in low-energy environments.
• Provides aesthetic value, enhanced views, a sense of place, and privacy to the property owner.