Erosion Response

From Beachapedia

"When it comes to inhabiting the coast, there is no philosophical middle ground. People adapt one of the two positions exemplified by Mohn (a homeowner) and Pilkey (a scientist): People are at the coast to stay, and nothing along the coast stays forever." - Hiney (2004)

What Is Erosion Response?

Erosion response is a measure of how well coastal management decision makers work to limit the extent of shoreline armoring and unsustainable coastal development, and encourage alternatives to armoring. For example, are new development projects set back from the coast far enough to avoid coastal erosion problems? Are setback standards based on the latest erosion rates? When existing development is damaged during a storm is reconstruction prohibited or are there incentives provided for relocation? Are there statewide policies to implement relocation (“managed retreat”) or policies that consider relocation a viable option? Are states employing regional policies that take into account cumulative effects of non-natural shoreline alterations? An evaluation of these factors for each state serves to bring attention to the states that are taking a proactive role in minimizing beach destruction and protecting beach health for future generations.

Through the formulation (if not already in place), implementation, and strict adherence to policies such as the ones mentioned above, states can overcome two fundamental obstacles to alternative erosion response practices outlined by the Oceans Studies Board (2007):

1) A lack of knowledge and experience among decision-makers regarding alternative options for shoreline erosion response, the relative level of erosion mitigation afforded by the alternative approaches and their expected life time, and the nature of the associated impacts and benefits.
2) The current legal and regulatory framework itself, which discriminates against innovative solutions because of the complex and lengthy permitting process that almost always considers these options on a case-by-case basis.

It should be kept in mind that erosion is not always a bad thing. For instance, erosion of glacial landforms provides the primary source of sand and cobble for Massachusetts' 1,500 miles of beaches, dunes, and barrier beaches. Without erosion, many of the Commonwealth's biologically productive bays, estuaries, salt marshes and tidal flats would not exist. Yet coastal erosion is considered a major economic problem in Massachusetts and nationally.

Coastal erosion is an integral part of natural beach processes. Beaches are not stagnant, but instead are dynamic systems that shift, migrate, fill and erode; sometimes taking and sometimes giving. While many coastal communities throughout the United States and around the world point to coastal erosion as the cause of their shrinking beaches, erosion really only becomes a problem when we build houses, roads and other structures too close to the water. Unfortunately that is how development has been occurring along our coasts, and we haven’t given our beaches the room they need to naturally maintain themselves. Compounding the erosion issues that many beaches face are sea level rise, storm damage, subsidence of land, and interruption of natural sources of sand caused by revetments and jetties. Faced with a steady inland migration of the ocean that may range from a few inches to several feet per year, coastal communities have limited options to deal with the situation.

The potential responses to coastal erosion when infrastructure is threatened include Seawalls, beach fill, and Managed Retreat.


Seawalls, Riprap revetments and other hard structures built to hold back the advance of the sea often fail and need to be rebuilt over and over again. This approach is not desirable for several reasons, not the least of which is that these structures inevitably lead to the loss of sand from beaches – sand trapped underneath and behind the seawall, and sand eroded directly in front and down drift of the seawall. Waterfront properties receive only a temporary respite, while public beaches are often lost for good.

Another approach is beach fill, also known as beach nourishment, whereby sand is typically dredged from a harbor or offshore source and pumped/placed/spread on a beach to widen it. Issues associated with beach fill include sand compatibility/quality, ecological effects, changes to the beach and offshore bottom contours, effects on wave quality, and damage to offshore reefs. In addition, these projects may be very costly and typically must be repeated every few years. Who pays for the project is often a difficult issue to resolve. And in some cases the sand sources are running out. That leaves the option of managed retreat. Managed or planned retreat (also known as managed realignment) allows the shoreline to advance landward unimpeded. As the shore erodes, buildings and other infrastructure are either demolished or relocated inland.

Coastal managers realize that in many situations attempting to stop erosion through structural or non-structural solutions is a losing battle. Shoreline protection efforts and/or their repeated maintenance would be too costly and ultimately ineffective at preventing further erosion. A Managed Retreat approach typically involves establishing thresholds to trigger demolition or relocation of structures threatened by erosion. Therefore, this approach is frequently coupled with several other planning and regulatory techniques including: shoreline planning, to identify high-risk areas where this type of policy would be the only cost-effective, long-term solution; regulating the type of structure allowed near the shore to ensure that buildings are small enough and constructed in a way to facilitate relocation when needed; and instituting relocation assistance and/or buy-back programs to help with relocation costs or compensate property owners when their property becomes unusable. While the overall policy emphasizes retreat, a managed retreat approach may allow some erosion control measures using soft-stabilization techniques to prolong the life of shorefront buildings and other infrastructure for a limited, defined period of time. However, hard stabilization structures or repeated beach renourishment are generally not permitted.

This approach may be less expensive then costly structural stabilization projects that may only be a temporary solution, especially in highly erosive areas. Managed retreat maintains natural shoreline dynamics and enables shoreline habitats to migrate inland as the shoreline erodes to prevent loss of wetlands and other intertidal areas.

Needless to say, managed retreat is not often a popular option and can be politically difficult to implement, especially where significant development has already occurred. However, managed retreat has been implemented successfully at several locations.

Perhaps the most famous example of managed retreat in recent years was the relocation of the Cape Hatteras Lighthouse 2900 feet inland in 1999. When constructed in 1870, the lighthouse was 1,500 feet from the shore. Protective measures to reduce the rate of beach erosion in front of the lighthouse provided a temporary solution, but by late 1987 the lighthouse stood only 160 feet from the sea and was in danger of collapsing. In 1999, after several years of debate and lawsuits aimed at blocking relocation, the National Park Service successfully moved the lighthouse back 2,900 feet over the course of 23 days at a cost of $9.8 million.

A similar issue currently exists with the Montauk Point Lighthouse in New York. The Army Corps of Engineers is proposing to expand the rock wall that surrounds Montauk Point. Concerned with increased erosion of adjacent beaches and lack of sand at down drift beaches, Surfrider Foundation’s Eastern Long Island Chapter is trying to convince authorities to investigate the feasibility of moving the lighthouse back away from the eroding cliffs to protect it for centuries to come.

A very early example of managed retreat occurred at Coney Island, New York. In 1888 the beach became so badly eroded in front of the Brighton Beach Hotel that waves threatened the structure. To save the 500-foot-long, three story hotel that weighed 6,000 tons, workers jacked up the entire hotel, placed it on 120 rail cars, and eased it inland six hundred feet.

An example of a coastal development that is ripe for relocating inland (and almost was) is The Riggings condominium development in North Carolina. The development in Kure Beach obtained permission to install a wall of sandbags in 1985. In 2008 (23 years after installation) the sandbags were still in place and a majority of the complex's 48 homeowners had rejected a $3.6 million federal grant that would have helped them relocate their oceanfront condominiums across U.S. 421. The grant would have dedicated oceanfront land the complex is currently on as parkland. In January 2008 the CRC denied the homeowners’ request for another extension of their sandbag permit. In 2013 the owners and the CRC were still battling over this issue.

A similar situation exists at the Wild Dunes Resort in Kiawah Island, South Carolina where the property owners are trying to hold out with sandbags until a beach fill project can be approved, funded and implemented.

Surfers' Point Plan

A project at Surfers' Point, Ventura is precedent setting because it incorporates managed retreat and in the longer term, may include removing Matilija Dam to re-establish the natural supply of sediment to the area beaches. The first phase of the Surfers' Point project was approved by the Ventura City Council in August 2009 to relocate a decaying bike path and restore the beach near Surfers Point and the Ventura County Fairgrounds. Construction of the initial $3 million phase, paid with one-time grants, began in October 2010. The restoration effort has been hailed as a model environmental approach to stabilize and restore 1,800 feet of beach near the fairgrounds. The project relocated the bike and pedestrian trail and parking lot on the ocean side of Shoreline Drive about 65 feet inland toward the fairgrounds. Then, several tons of cobblestone were spread at water’s edge, adding to the rocky shoreline. Sand was then laid over the cobblestones to help restore the area to a more natural beach habitat and prevent future erosion. Dunes were created using 3,500 cubic yards of sand delivered to the project area from Pierpont Beach where a large accumulation was inundating beachfront homes. The dunes were then seeded with native plants. More info.

Laws and Regulations

Erosion (both “natural” erosion and erosion that has been exacerbated by our interruption of natural shoreline processes) continues to eat away at our ever-more-populated shorelines. This has prompted continuing battles over whether coastal property owners can and ought to rebuild after their property is damaged in a storm. This issue is perhaps most particularly acute in states like Florida, Louisiana and Texas which have suffered substantial damage from recent hurricanes. Some states, such as Rhode Island have laws in place which prohibit rebuilding of residences and non-water dependent use industries on barrier beach dunes, if more than 50% of the structure is destroyed. Although it is understandable that states may want to take measures to protect coastal property owners, Massachusetts, Florida, Texas and Louisiana now have state-funded insurance programs which, in effect, subsidize high-risk shoreline development.

At the national level, the National Flood Insurance Program (NFIP) is intended to "reduce the impact of flooding on private and public structures. It does so by providing affordable insurance to property owners and by encouraging communities to adopt and enforce floodplain management regulations." NFIP is massively in debt and the program's policies have had the effect of encouraging development and re-building in many coastal and other low-lying areas that are at extreme risk from storm damage. The national coalition is made up of a diverse chorus of voices united in favor of environmentally responsible, fiscally sound approaches to natural catastrophe policy that promote public safety. The coalition believes that the Federal government has a role in encouraging and helping homeowners to undertake mitigation efforts to safeguard their homes against natural disasters. At the same time, the coalition opposes measures that put people’s lives at risk at the expense of taxpayers. Measures such as subsidizing artificially low rates for homeowners’ insurance policies help to encourage construction in environmentally sensitive and unsafe areas. The coalition is working to ensure that Congress does not incentivize people to live in harm’s way in places prone to hurricanes and floods.

North Carolina has banned the construction of seawalls along the coast yet is also considering a special exemption based on a “pilot” program for “terminal groins.” South Carolina's "no seawall" policy has come under repeated attack and a combination of groins and beach fill has emerged as a tentative compromise solution in some areas. As mentioned above, in several locations in both states, “temporary” walls of sandbags have been in place for many years. New seawalls continue to be built and proposed in California, including some that apparently exist only to facilitate new coastal development – a violation of the California Coastal Act.

In 2012 NOAA's Office of Ocean and Coastal Resource Management (OCRM) published a report How Coastal States and Territories Use No‐Build Areas along Ocean and Great Lake Shorefronts. The report looks specifically at where states and territories employ no-build areas (e.g., through setbacks, rolling easements, or zoning) along ocean and Great Lake shorefronts, typically on dry, privately owned land, to protect the public interest.

Positive Indicators

The good news is that surveys conducted for our State of the Beach report indicate a growing awareness and use of policies and programs to proactively address coastal erosion issues. A few examples include:


California is the site of two recent and significant managed retreat/relocation projects: a completed project in Pacifica and a project under construction in Ventura.


A newly updated and expanded edition of Striking a Balance: A Guide to Coastal Dynamics and Beach Management in Delaware took top honors in the educational brochures category of the 2005 Communicator Awards.

No construction may take place seaward of the "Building Line" without a Coastal Construction Permit or Coastal Construction Letter of Approval from the Department. Depending on location, the building line is 75 to 100 feet landward of the 7- or 10-foot elevation contour.

The DCMP has undertaken a significant revision of Delaware’s coastal setback regulations, incorporating the most recent shoreline information for the state into the Building Line and updated construction standards.


The Florida Legislature approved a bill to require that buyers of coastal property be given "meaningful disclosure" about the dangers of living in the path of hurricanes.

Sarasota County’s comprehensive plan establishes an official policy to use county funds to buy beach and waterfront property.


Georgia's Green Growth Guidelines help planners and developers, compare the benefits of using sustainable development strategies with conventional development approaches.

A Coastal Management Program goal is to “Develop and institute a comprehensive erosion policy that identifies critical erosion areas, evaluates the long-term costs and benefits of erosion control techniques, seeks to minimize the effects on natural systems, and avoids damage to life and property.”


In December 2007, Kaua‘i County Council passed a science-based shoreline setback ordinance that mandates a 40-foot minimum setback plus 70 times the annual coastal erosion rate as recommended in the Hawai‘i Coastal Hazard Mitigation Guidebook. On Maui, the required shoreline setback is now calculated on the basis of a present coastal erosion rate applied for 50 years.

Hawaii Sea Grant prepared Natural Hazard Considerations for Purchasing Coastal Real Estate in Hawai'i (May 2006). The University of Hawaii monitors over 80 beaches around the state to better understand the process of seasonal profile adjustment.


Maine produced Protecting Maine's Beaches for the Future (2006), A Proposal to Create an Integrated Beach Management Program. This comprehensive and forward thinking document is a must read for beach managers everywhere.

Under Maine's Coastal Sand Dune Rules no building having a footprint greater then 2,500 square feet can be constructed within the dune system unless the applicant can demonstrate "by clear and convincing evidence that the site will remain stable after allowing for a two-foot rise in sea level over 100 years."

Maine Coast Heritage Trust announced in August 2006 it had raised more than $100 million to accelerate land conservation on Maine’s coast. Maine Coast Heritage Trust’s “Campaign for the Coast” is the largest land conservation capital campaign in Maine’s history.


Maryland’s Comprehensive Coastal Inventory Program has mapped shoreline features, including shoreline structures, coastal access, natural features, bank height and condition characterization. There is now a full statewide inventory of the shoreline structures.

Maryland has a 75-foot setback from "normal high water" for new construction. FEMA regulations on floodplains specify that if flood damage is greater than 50% then FEMA funds can't be used to rebuild a structure.

A NOAA Coastal Management Fellow with Maryland's Coastal Program developed a Sea Level Rise Response Strategy for the State of Maryland. The strategy sets forth the policy and implementation framework for reducing the State's overall vulnerability to sea level rise in the coming years.


In 2005, the Massachusetts Supreme Judicial Court affirmed the authority of a local government to bar residential construction in a flood-prone area and ruled that the community does not have to compensate the owner for being unable to build a home on a seaside property.

Executive Order No. 181 discourages further development on barrier beaches by limiting state and federal funding for new support facilities that promote growth; gives priority status for relocation assistance to storm damaged barrier beach areas; and encourages public acquisition of barrier beaches for recreational purposes. A Coastal Hazards Commission report recommends acquisition of storm-prone properties though both the Department of Fish and Game/DCR using state funds and coastal communities using Coastal Preservation Act funds.


Erosion rates are used to calculate the appropriate setback distances for coastal construction. High Risk Erosion Areas are mapped on a County basis. The maps have 30-year and 60-year setbacks. Michigan law requires that the MDEQ conduct erosion studies to document the long-term rate of shoreline movement.

Structures threatened by erosion must be moved landward (where possible), protected by costly shore protection, or lost. Permits for shoreline armoring are usually not granted in high risk areas.

New Jersey

New Jersey's Coastal Blue Acres Program is designed to provide grants and loans to municipalities or counties to acquire important coastal lands for recreational and conservation purposes. There are setback requirements for new coastal development, based on measured erosion rates, designed to avoid erosion impacts for 30 to 60 years.

The Coastal Resources Toolkit on the Jacques Cousteau National Estuarine Research Reserve website consists of a set of New Jersey-specific resources to assist with land zoning decisions.

New York

The town of East Hampton has passed the Coastal Erosion Hazard Areas Act which creates a coastal erosion hazard overlay district and prohibits new structures.

New York requires a property owner to disclose if the property is located in a designated floodplain.

Coastal erosion hazard areas are defined and the only new structure allowed in these areas is a moveable structure. If non-conforming structures near the coast in erosion hazard areas are damaged more than 50% of their value, they cannot be rebuilt in the hazard area.

North Carolina

The North Carolina Conservation Tax Program is a tax incentive program to encourage landowners to protect environmentally sensitive lands, including those in high risk erosion areas.

North Carolina’s coastal setbacks are based on local average coastal erosion rates, multiplied by 30 or 60 depending on the size of the building to be built.

North Carolina has a longstanding ban on new hardened structures along the coastline.


Oregon has produced an educational DVD called Living on the Edge, Building and Buying Property on the Oregon Coast.

Division 21 of the Beach Bill requires the consideration of alternatives to coastal armoring, such as planned retreat or beach fill.

Oregon has created a Coastal Atlas website, which is an interactive, searchable, downloadable archive of geo-spatial data. It includes mapping and decision support tools.

Rhode Island

Setbacks are a minimum distance of either 50 feet from the inland boundary of the coastal feature or 25 feet inland of the edge of a Coastal Buffer Zone, whichever is further landward. In Critical Erosion Areas, the minimum distance of the setback is not less than 30 to 60 times the calculated average annual erosion rate.

Policies prohibit new development on undeveloped and moderately developed barrier beaches. Shoreline armoring is effectively prohibited along greater that 75% of the coast, including most beach areas.

On the dunes of barrier beaches, residential or non-water dependent structures that are more than 50% destroyed may not be rebuilt regardless of insurance carrier coverage.

South Carolina

The 1988 Beachfront Management Act mandated the establishment of a baseline, usually defined as the dune crest. Coastal setbacks are based on local average coastal erosion rates. The average coastal erosion rate is multiplied by 40 with a minimum setback distance of 20 feet. New owners must be informed if their property is located seaward of the setback line. A forty-year policy of retreat from the shoreline is established.

In 2007, DHEC-OCRM initiated a Shoreline Change Initiative to organize existing data collection and research efforts, identify additional research needs, and formulate policy options to guide the management of South Carolina’s estuarine and beachfront shorelines. New erosion control devices such as seawalls, bulkheads, and revetments are prohibited seaward of the setback line.


Construction cannot be conducted on the public beach, which extends to the line of natural vegetation (LOV), per beach/dune regulations. The public beach is a “rolling easement” that moves with the LOV.

Although there are no statewide setback requirements for new coastal construction, there are mandated setbacks in the City of Galveston, South Padre Island, Cameron County and Nueces County, which recently established a 350-foot setback.

A January 2003 report to the Texas legislature recommended: "Encourage the Land Office and the Office of the Attorney General to enter into a memorandum of agreement (MOA) on enforcement of the Open Beaches Act to prevent and remove any encroachments and interferences on the public beach."


Since 1991 the Coastal Program has helped to acquire and preserve over 1,800 acres of coastal lands.

The Virginia Institute of Marine Science (VIMS) - Center for Coastal Resources Management, Wetlands Program maintains a comprehensive database of permitted structures and other shoreline projects.

The brochure Shoreline Erosion Problems? Think Green helps ensure that nonstructural alternatives to shoreline erosion are considered and illustrates how using marsh grasses can secure property and benefit water quality and wildlife.


Department of Ecology, Southwest Washington Coastal Erosion Study and USGS produced a 1998 video At Ocean’s Edge: Coastal Change in Southwest Washington.

In 2007 rip rap was removed from the shore at Belfair State Park in the Lower Hood Canal area. The project included removal of a tidal swimming pool and creation of a sandy beach in its place. A rocky wall was removed to create a walking beach.

The Washington Department of Natural Resources’ ShoreZone Inventory provides GIS data for the location and type of shoreline structures along Washington’s marine shorelines. The Washington Coastal Atlas is a useful digital tool to learn about Washington’s marine shorelines and the land areas near Puget Sound, the outer coast, and the estuarine portion of the Columbia River.


Wisconsin has a clear and organized Hazard Mitigation Plan.

The Wisconsin Coastal Management Program recently developed a DVD, "Wisconsin Shores: Coastal Erosion in the Great Lakes."

Top 5/Bottom 5

People are often interested in how their state stacks up against others. Using the evaluation criteria discussed above, a “Top 5” and “Bottom 5” list of states was developed for erosion response. Here are the results. The states in each list are in alphabetical order.

Top 5


Coastal Hazards Commission preparing a report that will include a 20-year Coastal Infrastructure and Protection Plan, as well as recommendations to improve coastal hazards management coast-wide. Executive Order No. 181 discourages further development on barrier beaches by limiting state and federal funding for new support facilities that promote growth; gives priority status for relocation assistance to storm damaged barrier beach areas; and encourages public acquisition of barrier beaches for recreational purposes.


Erosion rates used to calculate setback distances. High Risk Erosion Areas are mapped with 30-year and 60-year setbacks shown. Structures threatened by erosion must be moved landward (where possible), protected by costly shore protection, or lost. Permits for shoreline armoring are usually not granted in high risk areas.

North Carolina

Setbacks based on average annual recession rates, natural site features, and the nature of the proposed development. Cape Hatteras Lighthouse relocated. Longstanding regulatory ban on seawalls and other hardened structures on the beach. Tax incentive programs encourage use of high risk land for conservation. Good erosion data.

Rhode Island

Setbacks a minimum distance of 50 feet from the inland boundary of the coastal feature or 25 feet inland of the edge of a Coastal Buffer Zone. In Critical Erosion Areas, minimum distance of setback not less than 30 times the calculated average annual erosion rate. Policies prohibit new development on undeveloped and moderately developed barrier beaches. Good erosion data and coastal hazards information. Shoreline armoring effectively prohibited along greater that 75% of the coast, including most beach areas.

South Carolina

1988 Beachfront Management Act mandated the establishment of a baseline. The setback line, based on the baseline is equal to the average annual erosion rate multiplied by 40. Act requires that new owners be informed if property is located seaward of setback line. Good public education and erosion data. 2007 Shoreline Change Initiative.

Bottom 5


No state setback requirements. No restrictions on the rebuilding of structures near the coast after they have been damaged by flooding. No real estate disclosure laws for homes in high erosion areas, in part because the state does not track high erosion areas. Guidance policies are poorly implemented and are not well-known by the permitting and funding agencies. ACOE continues to build and approve shoreline armoring.


Under the CCA, a permit is not required for the re-construction of any property destroyed by a natural disaster if the replacement structure footprint remains substantially the same. CCA: “Revetments, breakwaters, groins, harbor channels, seawalls, cliff retaining walls, and other such construction that alters natural shoreline processes shall be permitted when required to serve coastal dependent uses or to protect existing structures or public beaches in danger from erosion.” Also, under current interpretation of the Coastal Act, "new" structures can instantly become "existing" structures and are then eligible for protection. Shoreline armoring continues to proliferate.


No setback information found. Development allowed "on lands five feet or more above sea level or within fast lands.” Weak restrictions – “Nonstructural methods of shoreline protection shall be utilized to the maximum extent practicable. Shoreline modification structures shall be designed and built using best practical techniques to minimize adverse environmental impacts.” Little enforcement of weak regulations.

New Jersey

The in-place reconstruction of existing development, including storm-damaged development and expansions that do not increase the footprint of existing development remain largely unaffected by the coastal permit program. There are many shoreline structures in NJ that have led to beach loss. Although new structures are discouraged, they are still allowed under certain circumstances. About 95% of coastal development permit applications are granted.

Puerto Rico

Response to coastal erosion mostly crisis based, leading to engineered solutions that have a negative effect on the coastal environment. Several permitted/installed coastal projects seem to ignore coastal regulations and/or accepted best management practices. Very little policy or inventory information on shoreline structures. Fair coastal erosion data, but setbacks are not based on erosion rates.