Adaptation Tool Kit: Sea-Level Rise and Coastal Land Use
Zoning & Overlay Zones
Policy Goal: All
Type of Land: Developed, Developable, and Undeveloped Areas
The primary power that local governments use to control development in their community is zoning. Local governments adopt zoning maps that divide the community into different districts (or zones) based upon the types of uses that are permitted (e.g., residential, commercial, or industrial). The zoning ordinance then specifies the different regulations that govern development within that zone. For example, the zoning ordinance will specify how far structures need to be set back from the street, the density of development, and how large structures can be.
One method of zoning employed by local governments is overlay zoning2. Overlay1 zones allow local governments to superimpose additional regulatory requirements on an existing zone to add supplemental regulation in areas with special characteristics. They allow greater flexibility because they do not require the locality to disrupt existing zoning classifications. In order to create an overlay zone, local governments must (1) establish the purposes for creating the district, (2) map the district, and (3) establish the regulations to achieve the purposes for creating the district. Many localities already use overlay zones to protect areas with unique natural resources (e.g., beaches, wetlands and barrier islands) or cultural resources (e.g., historic properties).
Zoning for Sea-Level Rise
Local governments could create a “SLR overlay zone” for areas most vulnerable to impacts. Within the SLR overlay zone, the locality could impose special regulations such as prohibiting or conditioning: new subdivisions, expansion or major renovations to existing structures, and rebuilding of damaged structures. The overlay zone could also require that buildings be elevated.
Local governments could also create different overlay zones depending upon their adaptation goals for different areas, such as:
- Protection zones—areas with critical infrastructure and dense urban development, where the locality will permit coastal armoring. Local governments could require that soft armoring techniques be employed where feasible.
- Accommodation zones—areas where local governments will limit the intensity and density of new development and require that structures be designed or retrofitted to be more resilient to flood impacts.
- Retreat zones—areas where armoring will be prohibited and landowners are encouraged to relocate structures upland through tax incentives, acquisitions, or conservation easement programs.
- Preservation zones—areas where important ecosystems are designated for preservation and restoration to enhance important flood buffers or habitat.
State and Federal Sources Proposing Use of Policy to Adapt to Sea-Level Rise
The Virginia Governor’s Commission on Climate Change (“Governor’s Commission”) recommends that local governments “revise zoning and permitting ordinances to require [that] projected climate change impacts be addressed in order to minimize threats to life, property, and public infrastructure and to ensure consistency with state and local climate change adaptation plans.”
The Oregon Coastal Management Program recommends “using land use planning processes to address climate change—add consideration of climate change as a key element in current planning and permitting process."
Floodplain Management and the Endangered Species Act (A Model Ordinance)
This model ordinance for floodplain management was developed by FEMA under the National Flood Insurance Program (NFIP) and the Endangered Species Act (ESA). It is a template that cities, counties and tribes can customize and adopt which allows land users to comply with the NFIP and the ESA. This model case is enacted for the State of Washington, to be implemented at the local level.
Regulatory Tools Floodplain Regulations