Dimensions - September/October 2009 - 2

Living Shorelines Soft Stabilization Provides Sustainable Coastal Strategies While coastal communities comprise a small portion of the nation’s land area, they contain approximately half of the U.S. population. Consequently, growth in these areas has negatively impacted many critical coastal environments such as estuaries. To preserve natural resources and prevent erosion, waterfront property owners are embracing unique approaches that protect their property and address critical needs of estuarine ecosystems. State and local governments are also investigating sustainable methods or implementing policies that address growing demand and pressure on coastal natural resources. By using a “softer” shore stabilization approach, living shorelines are offering a balanced solution. Living Shoreline Characteristics Over the past two decades, a living shoreline approach has continued to gain favor by landowners and ecologists. Traditional shoreline stabilization methods, such as bulkheads and revetments, have typically resulted in permanently hardened shorelines, incapable of providing further coastal ecological benefits. Living shorelines—made up of coastal plantings that help control erosion and preserve natural characteristics—protect property while providing environmentally sustainable solutions that support estuarine habitats and ecologies. Cost-Effective Benefits Living shorelines can provide cost benefits to landowners and governments because the materials involved are typically lower in cost and easier to install. These systems often provide lower average annual maintenance costs and are more resilient to severe storm event damage. Support through the National Oceanic Atmospheric Administration (NOAA) Fisheries Service, Restore America’s Estuaries, and various statelevel trust funds are also available to communities initiating living shoreline restoration programs. Living shorelines are used in tidal wetlands with low energy and may involve multiple stabilization techniques. Many states have developed guidelines for homeowners, and each state has established a permitting process. Stabilization techniques include marsh creation through coastal plantings, beach nourishment or replenishment, and slope grading and terracing through coastal planting or additional natural materials to stabilize a slope. w h I c h p r o j e c t I S r I g h t f o r m y S I t e ? (source: Maryland Department of Natural Resources) Site Conditions Shoreline Location Water Depth (feet/near shore) Fetch (miles/distance to nearest opposite shore) Erosion Rate (feet/year) Low Energy (Nonstructural) creek or cove -1.0 0.5 2 or less Nonstructural Options Projects beach replenishment Erosion Control Treatment marsh fringe marshy islands biologs, groins Cost Per Foot $50-$100 Medium Energy (Hybrid) minor river -1.0 to -2.0 1.0 to 1.5 2 to 4 major tributary 2.0 to -4.0 2.0 or more 4 to 8 High Energy (Structural) mainstem bay -4.0 to -15.0 2.0 or more 8 to 20 Structural Projects bulkheads revetments stone reinforcing groins and jetties $500-$1,200 Hybrid Projects marsh fringe with groins marsh fringe with sills marsh fringe with breakwaters beach replenishment with breakwaters $150-$300 $350-$500
http://www.noaa.gov/fisheries.html http://estuaries.org/ http://shorelines.dnr.state.md.us/
Dimensions - September/October 2009

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