Overview of the Legal Framework

State and local governments will have to consider multiple questions of legal authority and compliance when implementing managed retreat laws and policies. Generally, state and local governments will proceed through a series of three different steps to determine whether they have the authority or power to implement a certain tool and if so, whether the government actions chosen to implement that tool are compliant with all relevant statutes, regulations, common law, and constitutional requirements. 

Step One: Authority

State and local coastal governments interested in implementing tools for managed retreat should first inquire about their legal authority to implement different tools. This step applies to all types of tools — planning, infrastructure-related, acquisition, regulatory, and market-based. 

The source of authority will vary based on the type of tool considered. The primary state and local powers that will come up in a managed retreat context include those for coastal, environmental, natural resources, and floodplain management and land use and zoning, as summarized herein. These powers are just a few among many that have been delegated to state, local, and in some cases regional entities, and do not constitute an exhaustive list of powers that may apply to implement legal tools for managed retreat. Depending on the structure of a state’s coastal, environmental, or natural resources programs, the state and local levels of government could have separate or shared jurisdiction. State agencies are creatures of the state and can only delegate those authorities that have been specifically delegated to them by their state legislature. 

Local governments tend to have primary authority to regulate land uses in their communities through zoning and floodplain ordinances. In particular, zoning ordinances provide the legal framework that governs the use and development of land in a municipality permitting different uses in different districts (e.g., residential, commercial, industrial).^{See footnote 1} Before implementing any zoning or land-use changes, however, local governments must ensure that they have the authority to utilize a tool under authority of state power, particularly in Dillon Rule states. In Dillon Rule states, state legislatures must delegate specific powers to local governments compared to home rule states, where local governments have broader authority.^{See footnote 2} Although, in general, local governments, particularly in home rule states, enjoy broad powers to take actions to protect the public health, welfare, and safety of residents under their existing police powers.

In the context of retreat decisions relating to public infrastructure, such as roads and bridges, states, local governments, and other public agencies owning or operating infrastructure should understand who has authority over the infrastructure assets in question, and what responsibilities that authority entails. For example, an agency’s duty to maintain infrastructure may be relevant in the context of decisions to phase out maintenance and potential for negligence claims (discussed further in the toolkit sections on Crosscutting Legal Considerations>Negligence and Infrastructure). Authority to formally abandon infrastructure may help relieve an agency’s duty to maintain and conform to state law,^{See footnote 3} but may not prevent a successful takings claim under certain circumstances (e.g., if it removes an abutting property owner’s only means of access). Questions relating to an agency’s duty to maintain and authority to disinvest in public infrastructure assets may be answered by looking to the jurisdiction’s statutory and case law.  

In some cases, state agencies or local governments may benefit from clearer statutory authority specifically enabling actions designed to address climate change impacts or facilitate managed retreat, warranting legislative actions to amend existing statutes or ordinances at the state or local levels. For example, many states already provide local governments the power to create zoning and overlay districts or Transfer of Development Rights programs for broad conservation purposes. Local governments, however, may require or benefit from explicit statutory authorizations to use either of those tools to achieve managed retreat goals, for example, to protect and remove development from wetland migration corridors. Explicit or clear statutory authorizations can encourage governments to take actions to adapt to climate change by removing the legal uncertainty around their authority to do as such. Regardless, it is important to emphasize that local governments generally have broad powers to take actions to protect the public health, welfare, and safety of residents, and should not let a lack of clear explicit legal authority be an excuse for failing to take actions to address climate threats, like sea-level rise, using existing police powers.

Step Two: Statutory and Regulatory Compliance

Next, state and local governments must ensure that their actions are consistent with federal, state, and local laws. In particular, the coastal zone presents policymakers with complex, often overlapping jurisdictions. Most commonly, coastal retreat will necessitate a review of coastal zone and floodplain management and wetlands laws at the federal, state, and local levels. Notably, the system for regulating wetlands alone can involve many statutes. At the federal level, the U.S. Army Corps of Engineers is one of the primary agencies that regulate activities in intertidal areas that affect wetlands under two statutes, the Clean Water Act^{See footnote 4} and Rivers and Harbors Act.^{See footnote 5} In addition, most states, in coordination with federal agencies, manage their coastal zones under the federal Coastal Zone Management Act^{See footnote 6} and may have special protections for coastal uses and resources, such as wetlands, where certain actions conducted in or adjacent to these resources may be prohibited or require specific mitigations through permit conditions or other approvals (e.g., consistency certifications).^{See footnote 7} For retreat strategies that have an emphasis or focus on conserving coastal wetlands or other resources like dunes and facilitating their inland migration, these laws may play a prominent role in shaping government actions. 

Given the interdisciplinary nature of comprehensive policies for managed retreat, these decisions could also implicate a range of other laws depending on the purpose of or need for a tool. For example, buyout strategies coupled with housing and infrastructure investments in receiving areas could require a municipality to evaluate hazard mitigation, infrastructure, affordable housing, and historic preservation laws. To ensure that all applicable laws are identified and addressed in decisionmaking processes, governments should seek to engage legal staff early and often and coordinate across relevant agencies. 

Step Three: Constitutional Compliance

The two primary constitutional protections governments must evaluate and balance in a managed retreat context are takings and due process rights for private property owners.

First, the Fifth Amendment of the U.S. Constitution mandates that the federal government shall not “take” private property for a public use or purpose without just compensation.^{See footnote 8} This provision of the Fifth Amendment has also been applied to states through the Constitution’s Fourteenth Amendment.^{See footnote 9} Under federal and state law, there are different types of takings that can result. Generally, courts apply a “per se” test to physical occupations^{See footnote 10} and regulations that deprive a private property owner of all or essentially all of his/her property’s economic value;^{See footnote 11} however, in a managed retreat context, most regulations designed to protect people, property, and the coastal environment fall within a “regulatory takings” category and will be evaluated under a case-by-case-specific balancing test.^{See footnote 12} Regardless, state and local governments have navigated takings limits and regulated the use of private property to protect sensitive coastal ecosystems. 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 to offset ecological impacts resulting from use of private property (federal takings rules and case law are examined further in the toolkit sections on Takings).

In addition to takings, governments must also ensure that managed retreat decisions do not violate a property owner’s due process rights under the Fourteenth Amendment. The Fourteenth Amendment provides that no government “shall . . .  deprive any person of life, liberty, or property, without due process of law.”^{See footnote 13} The U.S. and state constitutions require the governments to maintain both procedural and substantive due process rights. Procedural due process requires that governments provide people and entities fair notice of applicable regulations and an opportunity to seek administrative or judicial appeals. Conversely, substantive due process requires that regulations be “rationally related to a legitimate public interest.”^{See footnote 14} Although this is a low constitutional bar, which to some extent overlaps with requirements for regulatory takings, climate adaptation and managed retreat decisions must meet this level of constitutional scrutiny.