A living shoreline is a newer method for stopping shoreline erosion and protecting marsh areas. Unlike traditional structures like bulkheads or seawalls, which make erosion worse, living shorelines use as many natural materials as possible. These materials help absorb wave energy and protect shorelines from erosion more effectively.

Creating a living shoreline is called soft engineering. This process uses methods that follow ecological principles to stabilize shorelines. The natural materials used in living shorelines help create and keep valuable habitats. Common materials include sand, wetland plants, filled sand, oyster reefs, submerged aquatic vegetation, stones, and coir fiber logs.

Benefits and ecosystem services

• Helps keep shorelines stable
• Protects areas near water and places where water meets land
• Improves water quality by filtering runoff from land areas
• Helps create homes for both land and water animals
• Absorbs wave energy, which helps reduce erosion
• Keeps natural exchanges between land and water areas intact
• Provides better places for fish to eat and have babies
• Can be used in many different environments
• May cost less than traditional structures like seawalls and bulkheads
• Provides safe spaces for young aquatic animals to grow and feed
• Looks more natural than traditional structures

Design

When planning a living shoreline project, several important steps must be taken. Two key areas to consider before starting are understanding the rules for permits and choosing the best methods to restore the environment.

• Site Analysis: Before beginning a project, details about the area must be studied. This includes how fast the land is eroding, the height of the land, types of plants, how strong the waves are, wind patterns, soil type, and wave activity. These details help decide if the area is suitable for a living shoreline. Restoration plans are created after this initial study.

• Permitting: Before any work starts, permits must be obtained from the correct government agencies. All plans must follow local, state, and federal laws to avoid legal problems and ensure the project lasts for a long time.

• Site Preparation: After permits are approved, the area must be cleared of debris, unstable trees, and failing structures like bulkheads. Stormwater runoff issues must also be fixed before installing a living shoreline.

• Project Installation: Living shoreline structures often include planting marsh, riparian, or other water plants. Materials like bio-logs, organic fiber mats, and oyster shells are also used during installation.

• Maintenance and Monitoring: After the project is completed, the area should be regularly checked to collect data about its success. This helps improve future projects. The site must also be maintained by replanting vegetation, removing debris, and adding sand when needed. Materials should be checked to ensure they stay in place and help stabilize the shoreline.

• Clean dredge material and sand are used to build a sloped area that weakens waves and allows plants to grow. If a bulkhead is not present or has been removed, regrading, filling, and planting native vegetation can occur. If a bulkhead cannot be removed, sand can be filled in front of it, and vegetation can be replanted on the shoreline and embankment.
• Tree and grass roots help stabilize the area above high tide by holding soil in place. This reduces erosion, creates wildlife habitat, and filters water from upland areas. Riparian zones typically include grasses, shrubs, and trees, but the specific species depend on the local environment.
• Breakwaters control erosion and create habitat by reducing wave activity in open water. These structures, made of rock and oyster spat, are placed in areas with medium to high wave energy and arranged parallel to the bank. After installation, the shoreline becomes calmer, allowing marshes and intertidal habitats to form through replanting.
• Filter fabric is used to prevent soil loss under rocks. This porous material is placed under breakwaters and other structures.
• Geotextile tubes, about 12 feet in diameter, are filled with sediment and placed along the shoreline to weaken waves and protect against erosion. These tubes also support oyster reef development and help dispose of dredge material.
• Low-crested rock sills are made by placing rocks parallel to the shoreline underwater. These rocks reduce erosion by weakening wave energy. They are placed no higher than 6 to 12 inches above the mean high water mark and divided into sections to allow for boat passage and wildlife movement.
• Mangroves help stabilize shorelines by trapping nutrients and sediments and reducing wave energy with their roots. They are naturally found in subtropical and estuarine tropical areas, such as southern Florida, the Caribbean, and parts of southern Louisiana.
• Marsh grasses are planted up to the mean high tide line and in intertidal zones to break waves, provide habitat, and improve water quality. Studies suggest planting is most successful in spring in areas with existing marsh, mild winds, and less than 3 miles of open water nearby.
• Natural bio-logs and fiber logs are placed at the bottom of slopes or in water to reduce erosion. Made from biodegradable materials like coconut fiber, they hold sediment, retain moisture, and support plant growth.
• Natural fiber matting, made from jute, straw, or coir, is placed on steep slopes to reduce sediment loss and catch sediments carried by waves. It can also be used with riparian or marsh vegetation to improve bank stability.
• Rock footers are small rocks used to support bio-logs and add stability to slopes.
• Rubble and recycled concrete can form breakwaters offshore to weaken waves before they reach the shoreline. Adding oyster spat to these breakwaters improves water quality and creates habitat.
• Oyster shell reefs help reduce erosion and improve water quality by providing habitat for fish. Only clean oyster shells that have been dried in the sun should be used.
• Reef balls, which are hollow concrete balls, can create artificial reefs that support oyster growth. They reduce oyster poaching and are easier to manage than traditional oyster shell reefs.
• Seagrass beds act as natural barriers against erosion and improve water quality, stabilize sediment, and provide habitat for aquatic life.
• Wave Attenuation Devices (WADs) reduce wave energy before it reaches the shore. These devices also create habitat for marine life and help redeposit sand onto the shore.

Selected projects

• VIMS Teaching Marsh, Gloucester Point, Virginia
• Jamestown 4-H Camp, James River, James City County, Virginia
• The Hermitage Museum and Gardens, Norfolk, Virginia
• Longwood University's Hull Springs Farm, Westmoreland County, Virginia
• Jefferson Patterson Park and Museum, Calvert County, Maryland
• South River Federation, Maryland
• St. John's College, Annapolis, Maryland
• Magothy Beach Road, Pasadena, Maryland
• San Francisco Bay
• Piscataway Park, Potomac River, Maryland
• Delaware
• Havre de Grace, Maryland