Managed Retreat Toolkit

Living Shorelines

Introduction to Living Shorelines

Traditionally, property owners have turned to hard armoring or man-made engineered techniques like bulkheads, sea walls, revetments, dikes, tide gates, storm surge barriers, and groins to protect coastal development from flooding and erosion.See footnote 1 Increasingly, however, coastal states and communities are considering or encouraging the use of living shorelines or other “soft armoring” techniques (e.g., dune creation, wetland restoration) to avoid the negative impacts of hard armoring structures that can divert flooding and exacerbate erosion on surrounding properties and beaches.See footnote 2 While there are many definitions for what constitutes a living shoreline, a recent report by the National Wildlife Federation and Coastal States Organization provides as follows: 

The term “living shorelines” is used to describe a broad range of techniques and approaches for providing shoreline stabilization through the use of ecological, or “soft” approaches, as opposed to hard infrastructure. Although often solely associated with engineered approaches for shoreline stabilization, the concept of living shorelines spans the full range of natural defenses, from fully functioning natural systems to hybrid green-gray features. Such approaches, whether natural or engineered, typically serve to accommodate natural coastal processes as a means to reduce shoreline erosion, provide storm protection, and enhance habitat value.See footnote 3

The intended purpose of living shorelines is to conserve or enhance an existing shoreline so that the land-water interface does not move further landward. 

Credit: Kirsten Howard, New Hampshire Department of Environmental Services

As many state and local governments move to promote the use of living shorelines on private property, they are simultaneously evaluating ways to prohibit or restrict the use of hard armoring structures.See footnote 4 Living shorelines are commonly proposed as a more environmentally acceptable option to protect development and maintain coastal ecosystems. Policymakers are requiring property owners to evaluate soft armoring techniques like living shorelines before they can get a permit for hard armoring, and must use soft approaches, where feasible.See footnote 5 Governments can concurrently restrict the use of hard armoring techniques by prohibiting the construction of new armoring structures, limiting hard armoring to areas where living shorelines are infeasible, and, in some case, requiring the removal of a hard armoring structure after it has been damaged or if it is having negative impacts on coastal ecosystems like adjacent beaches or wetlands. 

 

Living Shorelines in a Managed Retreat Context 

In a managed retreat context, living shorelines can stabilize shorelines and preserve the many benefits (see table below) of coastal ecosystems for communities and the environment. Living shorelines can forestall or slow down the retreat of shorelines in some places, which can allow property owners to stay in place longer in response to sea-level rise and erosion. Living shorelines can also facilitate the inland retreat of coastal ecosystems that are unable to adapt-in-place. Specifically, living shorelines can limit or preclude the construction of hard armoring barriers that prevent the inland migration of wetlands, forests, and natural resources to higher ground establishment areas. 

State and local coastal, environmental, and natural resources laws and policies, and local land-use, zoning, and floodplain regulations provide the greatest opportunities to encourage or require the use of living shorelines and implement hard armoring restrictions. Governments considering living shorelines should evaluate how to develop effective laws and policies in light of the impacts of sea-level rise, flooding, and erosion in their particular jurisdiction. 

 

Policy Tradeoffs of Living Shorelines 

Administrative

  • Governments without an existing living shorelines program will likely have to invest in developing new regulations, policies, and guidance for their states or communities. This may also necessitate funding for new staff or technical expertise and training (e.g., science, community education, and outreach). 
  • Successful living shorelines programs require investments in education for landowners on the benefits of these types of approaches and for contractors who design and build them.
  • Depending on different environmental factors, living shorelines may not be feasible in certain areas (e.g., to maintain as much as or greater shoreline protection against flooding and erosion as a hard armoring structure). 

Economic

  • Living shorelines may be less expensive than hard armoring structures; however, they necessitate upfront investments and routine maintenance and monitoring, particularly after a severe flood or storm event. 
  • Living shorelines can help protect and maintain natural shorelines to reduce flooding and preserve the economic benefits of ecosystem services. 

Environmental

  • Living shorelines can prevent or limit the use of environmentally harmful hard shoreline armoring structures. 
  • Living shorelines can limit or preclude the construction of hard structures that act as barriers to inland migration of coastal wetlands and forests that are unable to keep pace with sea-level rise inundation, saltwater intrusion, and salinization, by“adapting-in-place” on the coast. Inland migration can mitigate the overall loss of important coastal habitats. 
  • Living shorelines and wetlands play important roles in protecting and restoring sensitive coastal ecosystems that deliver important ecological services like reducing flood or storm impacts, reducing flood insurance premiums for neighboring residents, and providing habitat for species like migratory birds.

Social/Equity

  • Living shorelines can help to protect culturally important resources (e.g., fisheries).
  • As a newer approach, living shorelines are more technically difficult to design and build. Lower-income communities and residents may need technical and financial assistance to facilitate the adoption of these approaches.
  • By disrupting natural sediment transport processes, hard armoring structures can lead to disproportionate impacts on neighboring properties (e.g., scouring, increased flooding). 

 

Legal Considerations for Living Shorelines

The primary legal considerations concerning living shorelines will relate to constitutional takings and wetlands, environmental, and natural resources statutes and regulations at the federal, state, and local levels. 

Jurisdictions can create living shorelines regulations and hard armoring restrictions to withstand potential regulatory takings challenges. The Fifth Amendment of the U.S. Constitution and analogous provisions of state constitutions prohibit governments from “taking” private property without just compensation.See footnote 6 While there are different types of takings, living shoreline hard armoring regulations designed to protect people, property, and the coastal environment will be evaluated under a case-by-case-specific balancing test.See footnote 7 Generally, governments can restrict or limit development in vulnerable coastal areas and floodplains, so long as a property maintains some economic value and a regulation serves a legitimate public interest, such as safety or offsetting ecological impacts from the use of private property.

Living shorelines provide an alternative to regulatory prohibitions on hard armoring structures. Living shorelines allow people to preserve their property and can thus preclude potential takings claims. However, private property owners could still challenge living shoreline regulations that restrict the use of hard armoring as a regulatory takings. To minimize potential legal risk, governments should: clearly justify the need for living shorelines based on best available science; articulate the purpose for these requirements in planning and other documents that put affected private property owners on sufficient notice; and allow exceptions for hard armoring structures, for example, based on prior use or where living shorelines will be less successful due to highly erosive coastlines or other environmental factors. For more information on takings and recommendations to minimize legal risk, see the Crosscutting Legal Considerations>Takings section of this toolkit. 

In addition to takings, living shorelines located in the coastal zone will intersect with a cross-jurisdictional framework that involves multiple federal, state, and local laws and agency players. The design and construction of living shorelines may require federal permits from the Army Corps of Engineers under the federal Clean Water ActSee footnote 8 and federal Rivers and Harbors ActSee footnote 9 for activities that discharge dredged or fill material into wetlands and/or create potential obstructions in navigable waterways. Living shorelines often require fill, and sometimes site grading, that triggers the need for approvals by the Army Corps, in addition to those at the state and local levels. At the state level, one or more agencies can be responsible for the permitting of living shorelines.See footnote 10  Additional state approvals may be needed for the use of state-owned submerged lands. States also possess the authority to review and approve Army Corps permits, both through Clean Water Act Section 401 water quality certification and Coastal Zone Management Act federal consistency authorities.See footnote 11  States can work together with the federal government to identify and implement strategies that reduce the permitting barriers associated with living shorelines.See footnote 12  At the local level, floodplain, environmental protection, and natural resources regulations may come into play for living shorelines that extend landward of intertidal areas, depending on their size and design and impacts on surrounding areas. In conclusion, governments and landowners should evaluate the range of federal, state, and local laws and agencies that may have regulatory authority or management and oversight over living shorelines.See footnote 13  

 

Practice Tips

When implementing living shorelines regulations and hard armoring restrictions in a managed retreat context, decisionmakers may consider the following practice tips to address and balance different policy tradeoffs: 

  • Develop flexible, place-based laws and policies for living shorelines: Among other factors, policymakers should consider natural environmental conditions and historical land-use patterns that will affect the physical and legal success and viability of living shorelines and their political and community acceptance and uptake. State and local governments can consider opportunities or exemptions for certain types of properties. For example, highly erosive areas or areas subject to a lot of wave action, or locations with a lot of critical infrastructure which has historically been protected by hard armoring structures may be less ideal candidates for living shorelines (e.g., East Hampton, New York). 
  • Evaluate how living shorelines regulations can be combined with other legal and policy tools for managed retreat: State and local governments can consider coupling laws and policies that promote or require living shorelines and prohibit or restrict hard armoring structures with other planning, acquisition, and regulatory tools to implement more comprehensive retreat strategies. In particular, coastal, wetland migration or ecosystem-specific, and local comprehensive plans are of particular relevance for justifying and coordinating decisions around coastal uses, development, and environmental conservation. Moreover, other acquisition and regulatory tools, like zoning and overlay zones, could be layered to implement living shoreline and hard armoring requirements over an appropriate spatial scale, for example in less dense areas prioritized for open space acquisition or wetland migration.
  • Invest in data at an appropriate scale: Physical impacts from sea-level rise, storm surge, different types of flooding (e.g., precipitation), and coastal erosion are the impetus or drivers for state and community decisions to retreat. Governments will need the best available scientific data and information on an appropriate scale to effectively develop and implement living shorelines and hard armoring restrictions. While some governments may already have the necessary data, others will have to invest in or look for opportunities to obtain data before they can consider promoting the use of living shorelines. Federal agencies (e.g., National Oceanic and Atmospheric Administration, U.S. Geological Survey) and conservation nonprofits (e.g., The Nature Conservancy) may already have data on an appropriate scale that governments can use to inform the development of setbacks and buffers. Alternatively, state and local governments may have to consider grant or other funding opportunities to initiate partnerships to collect this data from scratch.

    While scientific data is important, community residents — particularly those who have lived in an area for a long time or have historical or cultural ties — can provide additional types of data or information based on historical or lived experiences that, among other things, can help governments better understand cyclical or long-term changes on the coast to inform climate adaptation discussions. Governments, therefore, should aim to make data collection processes as comprehensive as possible and reach out to more than just scientific and coastal experts. Complementary datasets will be key to crafting well-rounded, interdisciplinary approaches for managed retreat. 
  • Support the use and development of living shorelines through education and outreach programs: State and local governments can increase the awareness and potential uptake of living shorelines by investing in education and outreach programs for private property owners and contractors. In addition to educating private property owners about the benefits and use of living shorelines, technical expertise from contractors and other experts will be required to effectively design, site, monitor, and maintain living shorelines. Governments can also look for opportunities — including developing public-private partnerships, providing living shorelines grants to community residents, or drafting permitting guidance — to ease the administrative, economic, and social burdens on private property owners and contractors to enhance the environmental benefits of living shorelines. For example, the North Carolina Department of Environmental Quality maintains a website on “Resources for Homeowners and Professionals” to learn more about living shorelines. The state has even worked with partners to hold a series of “lunch and learns” or “dinner and a movie” for marine contractors to educate them about the benefits of living shorelines versus bulkheads. 
  • Build public-private partnerships: State and local governments can build various types of partnerships to offset some of the administrative, economic, and social costs and enhance the environmental benefits of promoting the use of living shorelines. For example, public-private partnerships with universities or nonprofits could be used to collect localized data and provide technical assistance to property owners and marine contractors interested in or required to construct, monitor, and maintain living shorelines and support education and outreach efforts to create awareness of these programs and their associated benefits. In addition, these partners could leverage funding and expertise to engage in broader ecosystem restoration efforts or purchase adjacent properties for public purposes (i.e., open space acquisition or conservation easement) to facilitate larger-scale coastal conservation and inland migration.
 

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