Shifting Coastlines: Managed Retreat Strategies for Cities Addressing Coastal Erosion

June 18, 2020

As climate change and sea-level rise accelerate erosion, cities and counties along the California coast must act to protect coastal resources and property from the landward march of the sea. To buffer these interests against the effects of coastal erosion, local agencies have adopted a wide variety of management strategies. Where landowners are reluctant to abandon economic investments and resources on the coast, planners have often favored traditional protective measures, such as hard armoring (e.g., seawalls and revetments) or beach nourishment (sand replacement). Recent years, however, have seen a shift towards adaptive strategies that preserve the social and ecological value of beaches, estuaries, and similar habitats that can be threatened or destroyed by hard coastal armoring. One strategy in particular—known as managed retreat—is increasingly at the fore of coastal planning conversations.  

Managed retreat refers to deliberate efforts to remove or relocate existing development from vulnerable areas and to limit new development in those areas. Although the end goal of managed retreat is always the same—to shift development from high risk to lower risk zones—there is no one-size-fits-all approach to achieving that goal. Rather, local agencies can tailor their adaptive responses to their unique values and priorities by selecting from a wide menu of land use planning strategies. Jurisdictions in California and elsewhere have already begun implementing managed retreat strategies by repurposing existing policy tools and funding mechanisms.  

Most managed retreat policies fall into one of two categories. The first and more conservative group includes policies that discourage development and renovation in high-hazard areas. These policies are often the most politically feasible because they allow existing structures to stay in place until natural forces demand otherwise.   

The second category includes tools that empower local agencies to more directly facilitate retreat and relocation. A few examples of these strategies are summarized below.   

Permit Conditions 

The California Coastal Commission certifies Local Coastal Programs (LCPs) for many jurisdictions in the Coastal Zone. Pursuant to that certification process, local jurisdictions gain the authority to review and issue Coastal Development Permits (CDPs). Cities and counties may make the issuance of CDPs contingent on certain development conditions, including conditions that facilitate managed retreat. 

For example, the City of Malibu adopted a shoreline and bluff development ordinance as part of its LCP Local Implementation Plan. The ordinance encompasses development standards, permit and application requirements, and other measures designed to mitigate the adverse impacts of coastal development. In addition to ensuring that new development does not cause or contribute to coastal erosion, these measures discourage development that requires the construction of hard coastal armoring. Where proposed development does include a shoreline armoring, the City cannot grant a CDP unless it finds, among other things, that “there are no alternatives that would avoid or lessen impacts on shoreline sand supply, public access or coastal resources and [the proposed development] is the least environmentally damaging alternative.” Together, these conditions help shift new development away from high risk areas.  

Zoning Overlays 

A zoning overlay creates a special zoning district over an existing zoning district that adds regulations applicable to the underlying properties. Zoning overlays can be used to restrict development in hazardous and vulnerable areas and to encourage landowners to shift development away from eroding coastlines. For example, the City of Monterey established its Special Setback Overlay District “to provide a mechanism for increasing setbacks along scenic streets and highways and the shoreline of Monterey Bay, El Estero and Roberts Lake.” The overlay serves the dual goals of protecting natural resources and ensuring that coastal development is harmonious with the surrounding environment. Rather than imposing one uniform setback on the entire Coastal Zone, the overlay mechanism allows the City to develop a unique setback for each area any time it amends the zoning map to add a new overlay.  

Jurisdictions seeking to facilitate managed retreat could establish similar setback overlays to gradually guide development out of vulnerable areas. So long as the baseline for the setback migrates with erosion (for example, if the setback is based on the average mean high water line over the last five years), the developable area will migrate as well.  

Transferable Development Rights 

Transferable development rights (“TDRs”) can provide additional incentives to shift development away from high-risk areas. TDR programs work by detaching development rights from individual parcels. The jurisdiction then designates the area to remain undeveloped—the “sending area”—and a corresponding area capable of sustaining higher density development—the “receiving area.” Landowners in the sending area can then sell their development rights to developers in the receiving area, allowing those developers to build to greater densities than would otherwise be allowed. This process ensures that all landowners recognize the economic development potential of their properties.  

Although TDRs are not new in California, local jurisdictions have not yet employed them at scale in response to coastal erosion. However, such use is well established elsewhere. For example, the town of Ocean City, Maryland adopted a TDR program to facilitate a dune restoration project following prolonged erosion of the town’s beachfront. The town established a registration period during which owners in the sending district could elect to participate in the TDR program. Each registrant transferred ownership to the town or the state at the time of registration and received a receipt for development rights in exchange. Registrants could then transfer those development rights to a project in the receiving district, and the development rights would attach to that project in perpetuity.  

Eminent Domain 

Finally, cities can use eminent domain to condemn homes in hazardous and vulnerable areas that are unsafe for habitation. The City of Pacifica has recently used eminent domain to condemn structures rendered uninhabitable by coastal erosion. The land has now been converted to a public trail.  

Pacifica employed eminent domain reactively rather than as part of a formal managed retreat policy. However, where local agencies expect to remove existing development in advance of future erosion forecasted by scientific modeling, eminent domain can be incorporated into long-term retreat planning. In this way, eminent domain can be a powerful tool to remove unsafe development from vulnerable areas before they become uninhabitable.  

For more information, contact SMW attorney Ellison Folk. 

By Ellison Folk & Andrew Miller 

This article is intended for information purposes only and is not legal advice. This article is not intended to be a source of solicitation. This article is intended, but is not promised or guaranteed, to be correct, complete, and up-to-date. This article does not constitute a guarantee, warranty, or prediction regarding the outcome of any legal matter. Readers should not act on the information provided in this article without seeking professional legal counsel.