State of the Beach/State Reports/CA/Shoreline Structures

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California state law requires homeowners to obtain a Coastal Development Permit from either their local government, if the local government has a certified Local Coastal Program (LCP) or from the Coastal Commission, if an approved LCP does not exist. The LCPs can provide more detail, such as the type of coastal structure preference. All California LCPs require technical or geologic reports to support the proposed coastal armoring project. Permits generally require the applicant to submit site plans for the protective device and a "wave run-up study" that details the beach profile of the site and potential impacts of the device to the surrounding environment.

The California Coastal Act addresses shoreline structures in sections 30235, 30253 and 30610.

The key section in the California Coastal Act that sets the policies governing shoreline structures for existing development is Section 30235, which states:

"Revetments, breakwaters, groins, harbor channels, seawalls, cliff retaining walls, and other such construction that alters natural shoreline processes shall [emphasis added] be permitted when required to serve coastal-dependent uses or to protect existing structures or public beaches in danger from erosion and when designed to eliminate or mitigate adverse impacts on local shoreline sand supply. Existing marine structures causing water stagnation contributing to pollution problems and fish kills should be phased out or upgraded where feasible."

The definition of an "existing development" is important here. The California Coastal Act does not clearly define an existing development. Many Coastal Commission decisions apparently have been based on the interpretation that once a structure is approved and built that it is considered an “existing development.” This means that shoreline protection structures can potentially be placed in front of new homes that experience unexpected erosion just a few years (or even months) after they are built. An alternative interpretation is that "existing development" was meant to be defined as development that existed at the time of the adoption of the California Coastal Act in 1976, although legal challenges have so far failed to make that interpretation stick.

Legislation was introduced in 2002 that would have changed the word "shall" to "may", thus giving the CCC more discretion in permitting coastal structures. The legislation was withdrawn and is being reworked for possible later introduction and consideration.

NOAA's 2010 evaluation of California's Coastal Management Program notes:

"The California Coastal Act does not specify direction for addressing every type of hazard but says that new development shall minimize risks to life and property in areas of high geologic, flood, and fire hazard; and shall assure stability and structural integrity, and neither create nor contribute significantly to erosion, geologic instability, or destruction…or…require the construction of protective devices that would substantially alter natural landforms along bluffs and cliffs. The California Coastal Commission’s staff geologist and coastal engineer work with other Commission staff analysts in aspects of coastal hazards through LCPs, coastal development permits, partnerships, and outreach efforts to fulfill those mandates. There is a dichotomy, however, in that the Commission must always balance the requirement to allow shoreline protection to halt coastal erosion (under most circumstances) with the need to protect coastal resources and shoreline dynamics."

In May 2015 Stanford Law School, Environment and Natural Resources Law & Policy Program released 2015 California Coastal Armoring Report: Managing Coastal Armoring and Climate Change Adaptation in the 21st Century. The report's findings address how coastal decision-makers might better analyze, prevent, and mitigate shoreline armoring impacts and eliminate institutional incentives that have led to intense coastal development and maladaptive responses to coastal changes. The key recommendations of the report include:

"1. Advance stronger statewide laws, policies, and funding mechanisms that discourage armoring and encourage non-armoring responses to erosion, storm events, and sea level rise. These responses include, where feasible and appropriate, natural protective infrastructure and relocating property away from coastal hazards.
2. Ensure that local coastal planning mechanisms are used to incorporate a broader set of sustainable adaptation strategies and to discourage armoring.
3. Support development and implementation of measures, including insurance programs and regulations, that require and/or incentivize private property owners to assume the risks of developing in high-hazard areas and that facilitate relocation away from hazardous areas.
4. Where possible, pursue non-armoring responses to sea level rise and related coastal hazards for state-owned and private lands, such as relocating development (e.g., buildings, parking areas, roadways, utilities) and using other managed retreat strategies.
5. Improve the availability of relevant data, guidance, and technical resources."

Section 30253 is also relevant. This policy, which applies to new development, is cited and discussed in the Erosion section of this report.

Section 30610(g) addresses the reconstruction of existing shoreline structures destroyed by a disaster, defined as any situation in which the force or forces which destroyed the structure were beyond the control of its owner. The destroyed structure can be rebuilt without a permit but shall not exceed either the floor area, height, or bulk of the destroyed structure by more than 10%. Again, an “existing” is not defined above meaning that new shoreline structures may be rebuilt 10% larger after storms.

Section 30611 addresses emergency permits for shoreline structures. Emergency permits are granted when immediate action by a person or public agency performing a public service is required to protect life and public property from imminent danger, or to restore, repair, or maintain public works, utilities, or services destroyed, damaged, or interrupted by natural disaster, or serious accident. Nothing in this section authorizes permanent erection of structures valued at more than twenty-five thousand dollars.

Rebuilding more than 10% of a damaged structure requires a new coastal development permit, providing the opportunity to assess whether the new structure will be safe from flooding in the future.[1]

Monterey Bay Shoreline Management Planning
The Monterey Bay National Marine Sanctuary (MBNMS) is a federally-protected marine area offshore of California's central coast and encompasses 276 miles of shoreline. This coastline includes both pristine areas such as Big Sur and more developed areas such as Santa Cruz. Approximately 14 miles of the coastline are currently armored and this figure is expected to double if current shoreline development trends continue.

The Sanctuary must authorize and can place conditions on any California Coastal Commission permit for armoring projects below mean high tide. In the past, MBNMS review focused primarily on minimizing construction impacts and not on the long-term effects of the structure. Many seawalls also have been constructed without the Sanctuary's authorization. Therefore, to more effectively consider long-term and regional impacts from these armoring projects and improve interagency coordination on the permitting process, MBNMS initiated a joint evaluation with the Commission to develop a regional approach to coastal armoring which would be incorporated into the Sanctuary's management plan. MBNMS has published a discussion of coastal armoring on their website.

The MBNMS convened a workgroup in 2003 with representatives from the Commission, U.S. Geological Survey, California Department of Transportation, California Department of Boating and Waterways, U.S. Army Corps of Engineers, and scientists from local institutions to develop an action plan for a proactive regional approach to coastal armoring. The action plan calls for the following:

  • Developing guidelines for a sub-regional planning approach to coastal armoring by discouraging armoring in pristine or sensitive areas, promoting restoration and improved armoring techniques in urban zones which are already heavily armored, and instituting case-by-case review and additional research for areas in between.
  • Identifying appropriate planning sub-regions based on the following criteria: the extent of existing armoring; the types of armoring in place; the potential for new armoring requests; the types of structures to be protected; the level of development in the area; the biological sensitivity of habitats; geological units; beach nourishment needs; and shoreline orientation and erosion rates.
  • Identifying preferred types of coastal armoring, including more natural alternatives for specific conditions and geographic locations, taking into account environmental, aesthetic and public access concerns.
  • Identifying preventative measures aimed at reducing the need for coastal armoring. Considerations may include increased setback requirements, incorporation of a "no seawall" policy for situations when coastal agricultural land is converted to development, and requiring new setback requirements for demolition/rebuild projects in urban areas.
  • Reducing the of use emergency permits through better predictive erosion analyses, potential alteration of current guidelines regarding initiation of work, and more proactive regional planning.
  • Pursuing a pilot program to investigate and assess environmentally sound alternatives to coastal armoring.

The pilot project in southern Monterey Bay began in January 2005. The Southern Monterey Bay Coastal Erosion and Armoring Workgroup is overseeing the project and has already synthesized the scientific information related to coastal erosion and armoring in the pilot area, identified existing structures threatened by erosion, and outlined some potential alternatives to shoreline hardening. The workgroup will continue to identify at-risk areas, potential response options, and criteria for selecting an option to implement. Finally, the workgroup will recommend strategies for implementing the regional action plan based on the process they developed during the pilot project. The recommendations stemming from the pilot project will guide the Commission, Sanctuary and local jurisdictions on how to evaluate future armoring applications and address shoreline erosion more holistically within the Monterey Bay region.

Although the pilot project is still in its infancy, it has already encountered several challenges including how to reach a consensus on which erosion rate data to use given that different scientific studies have produced different results. In addition, the workgroup must decide how best to consider both episodic events such as El Niño that can cause more severe short-term erosion, as well as chronic erosion, which erodes gradually over the long term. Finally, when determining shoreline management options, the workgroup must be sure that they are balancing the need to protect private property with the need protect public beaches, as beaches are often impacted directly and indirectly by changes in sand transport caused by armoring. Balancing private property versus public access needs includes the sometimes-difficult task of putting an economic value on non-market uses, such as public access and commercial use of the beach.


According to CCC staff, California does not currently have a statewide inventory of shoreline structures. The CCC has a general inventory from the permit tracking system. The California Coastal Commission is compiling and working on a mapping project for the shoreline protection structures in California. This may be available soon. Contact the California Coastal Commission for availability.

The CCC does have inventories for selected areas. For example, their website provides information on the extent of armoring and beach fill projects in the Regional Cumulative Assessment Project (ReCAP) reports for Malibu and Monterey. The results of these studies are discussed further below.[2]

The California State Coastal Conservancy has an ArcView "shapefile" of shore-parallel structures developed as part of a recent project, but this information has not been verified for accuracy.

An exciting development in documenting coastal conditions and tracking coastal erosion, coastal structures, and other changes in the shoreline is the California Coastal Records Project. This project was initiated and carried out by Kenneth and Gabrielle Adelman, who in 2002 flew the entire California coast and took detailed low-level photographs. Since that time, the website has been enhanced by adding both historical photographs and sets of yearly update photographs.

Over the past three decades, the extent of shoreline armoring (including direct armoring such as revetments and seawalls, and areas protected by breakwaters and groins) has increased substantially. In 1971, California's coastline had at least 26.5 miles of shoreline armor. By 1992, California had approximately 129 miles of coastal armoring, or approximately 12% of the coastline.[3]

The California Beach Restoration Study (2002) indicates "only" 102 miles of coastal armoring. The total percentage of the coast verified as armored in this investigation (9% or 102 miles (165 km)) is less than that reported in the prior inventory (11.8% or 129 miles (208 km); Griggs, Pepper and Jordan, 1992). The authors believe that this is due to some local government planners having reported the length of rip-rap or other structures that were protecting interior margins of marinas and flood or bank control projects along river mouths in their estimates of total armoring in their region. Another source of error may be the inability in some cases to recognize low relief structures or those that have been designed to match the existing bedrock from oblique low altitude aerial photography.

Following is a county-by-county estimation of the percentage of armored coastline, based on work by Dr. Gary Griggs of UC Santa Cruz.

County 1971 Armor % 1998 Armor %
Del Norte 3 0
Humboldt 0 0
Mendocino 0 0
Sonoma 0 2
Marin 1 2
San Francisco 14 17
San Mateo 0 11
Santa Cruz 7 19
Monterey 0 1
San Luis Obispo 0 1
Santa Barbara 3 13
Ventura 27 45
Los Angeles 3 31
Orange 0 29
San Diego 5 31

One factor made evident by these statistics is that armoring is not so much caused by erosion as it is by development located too close to the ocean. The intense shoreline armoring in these populated areas adversely impacts the public, because the most populated areas also have the most heavily used beaches. Thus, California's most popular and heavily used beaches also tend to be the beaches with the most shoreline armoring. Overall, about 30% of the southern California coastline is armored (70 miles of armoring along 232 miles of coastline).

Important reference documents regarding shoreline structures include the following:

In 1994, the California Department of Boating and Waterways and San Diego Association of Governments produced a report titled the Shoreline Erosion Assessment and Atlas of the San Diego Region. The report illustrates for each part of the coast from Dana Point to the Mexican Border the threats to coastal development, environmental resources, and recreational resources. The report uses risk assessments to classify the threats to the studied resources. [4] The report also identifies sections of the coastline that have "shoreline protection" (Rip-Rap, Concrete Seawall, Timber Seawall, Sheet-Pile Seawall).

The previous statistics show the accelerating trend in shoreline armoring along California's coast. Recent research indicates that this trend is likely to hold steady in the future. Recently, the Coastal Commission completed reports on cumulative assessments conducted in Santa Cruz and Malibu (known as ReCAP). The Malibu ReCAP study stated that approximately 14.8 miles or 45% of the Malibu coastline has shoreline armoring, but even more important, is that, "...future build-out of shoreline lots indicate that up to 5 miles of additional shoreline (or an additional 15% of the project area shoreline) could be armored with hard structures."[5] This trend in Malibu is indicative of developed areas along the entire coast. Future infill development is also likely to receive permits for shoreline armor, which will result in more beach loss for the public.

The Monterey/Santa Cruz ReCAP study also analyzed shoreline armoring and coastal hazards. Much like the Malibu ReCAP, this study provides some alarming findings about the spread of shoreline armoring and its impacts on the public beach:

Between 1978-1994, approximately 2.4 miles of armoring was authorized in this ReCAP area. With continued implementation of existing policies, an estimated 27 miles, or approximately one-third of the ReCAP coastline, could be armored in the future. One of the major findings of the ReCAP analysis was a need for regional analysis when addressing shoreline erosion. ReCAP recommended the development of regional plans to help address regional concerns and ensure a full review of alternatives to shoreline protective devices. Armoring of the coast also affects public access through the physical encroachment of seawalls and revetments onto beaches, and by affecting sand supply. Armoring in the region (through 1994) covered an estimated 25 acres of beach.

A major finding of this effort is that current coastal policies support the use of public shoreline and public resources to protect private property and if the current situation continues, more and more of the public shoreline will be lost as a public resource. While only an eighth of the ReCAP coastline is now armored, over a third of the ReCAP coastline has the land use and physical characteristics which could require armoring in the future. None of this includes the shoreline already protected by groins, jetties and breakwaters. There are substantial portions of coastline which can be affected by the land use and armoring policies which are in effect.[6]

A significant shoreline armoring project in the Santa Cruz area is the one along 41st Street in Santa Cruz, near the surfing areas Pleasure Point and The Hook. Further discussion of this project can be found in a recent USGS study of the effects of the proposed shoreline armoring.

Shoreline armoring has also been proposed/implemented at Goleta Beach (also see below) and has been considered as part of a regional beach fill project in San Diego County, at San Onofre State Beach and at Capistrano County Beach in Orange County.

CCC staff reported the following regarding shoreline structure permitting activity in California for the years 1997-2002:[7]

Year Permits for "Hard Structures" Repair Permits for "Hard Structures" Permits for "Soft Structures"
2002 9 (2 removals) 29 4
2001 21 (1 removal) 32 14
2000 24 (3 removals) 15 11
1999 10 (3 removals) 17 5
1998 52 (4 removals/13 temporary) 39 2
1997 17 (1 removal/1 temporary) 11 5

The state is working to develop statewide information on many important coastal resources. The Ceres website shows much of this information and the State Legacy Project started recently to collect and display mapped information. One of the CCC's main functions is to maintain and protect coastal resources. A map of shoreline protection could be part of the work being undertaken by Ceres, the Resources Agency, the Legacy Project, or the California Coastal Sediment Management Work Group. At this point, there are not plans to develop a statewide map of human-constructed features on the shoreline.[8]

California Sea Grant funded a three-year project to examine the effectiveness of seawalls and other hard structures in preventing bluff failure in San Diego County, where there is a long history of bluff failures causing death and property damage. A group of structural engineers at UC San Diego, led by Dr. Scott Ashford, digitized and then analyzed old and recent aerial photos of the coast, building on some of the photo-imaging techniques developed by Dr. Gary Griggs at UC Santa Cruz. These images were then used to estimate erosion rates along stretches of the coast where seawalls, riprap, and soil-cement buttresses have been built. Results of the study were summarized in a 2005 article in the LA Times. The study was published in The Journal of Coastal Research in 2006.

From the report's abstract:

"The results indicate that seacliffs provided an estimated 67% of the beach-size sediment to the littoral cell, followed by gullies and rivers at 17% and 16%, respectively, over the period of the study. The total volumetric seacliff erosion rates were used to back-calculate average annual seacliff face retreat rates for the study period. These rates ranged from 3.1 to 13.2 cm/yr and averaged 8.0 cm/yr for the Oceanside Littoral Cell.

Comparison of these results to previous studies suggests that the relative seacliff sediment contributions may be higher than previously thought. Conversely, beach-sediment contributions from gullies were significantly lower compared with previous studies. This is likely because of the episodic nature of gullying and the relatively dry study period. Nevertheless, the results of this study indicate that seacliff sediment contributions are a significant sediment source of beach sand in the Oceanside Littoral Cell, and the relative annual seacliff beach-sand contribution is likely higher than previous studies indicate."

Surfrider Foundation's San Francisco Chapter has been involved for many years in trying to prevent or remove armoring from the Sloat Avenue area of Ocean Beach and other nearby coastal areas. Read their blog on this and the latest on the Ocean Beach Master Plan.

Surfrider Foundation's Santa Barbara and Isla Vista Chapters proposed implementation of a managed retreat project at Goleta Beach County Park, called Goleta Beach County Park Managed Beach Retreat Project 2.0 which would have involved the removal of an asphalt parking lot and a rock revetment. This plan was ultimately rejected by Santa Barbara County, leading to the Coastal Commission issuing an after-the-fact permit for the west-end revetment. Within months, amid reports of more damage from heavy surf, the commission approved the construction of a $350,000 emergency barrier of “geotextile” mesh ​— ​layers of plastic fabric filled with compacted dirt and stones ​— ​for unprotected portions of the park bluff. The geotextile barrier was finished in April 2016. It was heralded as a “softer” approach to coastal protection ​— ​until the waves tore it up in February 2017. In the aftermath of these storms, tangles of plastic lay strewn about the beach, and yards of soggy black mesh drooped from the bluffs. Large pieces of plastic soon made their way past the mouth of Goleta Slough. During the February 2017 storms, citing an “unexpected occurrence in the form of erosion” that was threatening park structures, the state Coastal Commission granted emergency permits for more boulders on Goleta Beach. The project connected two previous barricades, about 1,800 feet long overall, that were installed more than a decade ago at the east end in front of the café and at the west end near the UCSB campus. The county was given until mid-May 2017 to apply for a long-term permit for the latest section, which is underlain with plastic mesh. More on this.

The Fiscal Year 2017 Civil Works Budget for the U.S. Army Corps of Engineers provides $4.62 billion in gross discretionary funding for the Civil Works program. This budget lists proposed projects and the associated budget justification by state.


Lesley Ewing
California Coastal Commission
45 Fremont Street, Suite 2000
San Francisco, CA 94105
(415) 904-5291

Gary Griggs
Professor of Earth Sciences
UC Santa Cruz

Perception of Effectiveness

California's regulations and policies attempt to balance the need for armoring to protect private developed property against the need to preserve public beaches. The increasing amount of California's coastline that is being armored indicates that existing state policies are not effective in preventing continued shoreline armoring and associated destruction of beaches. As development pressures mount along the coast, there are likely to be continued proposals for shoreline armoring projects to protect structures built too close to the ocean. An effort during 2002 to modify Section 30235 of the California Coastal Act to give the CCC more discretion in reviewing proposed shoreline structures was not successful. Proposals to amend Section 30235 are likely to be re-introduced in the future.

Two state guidance documents that will likely influence future policy regarding erosion response and shoreline structures are the Statewide Sediment Management Master Plan and the California Beach Restoration Study. The latter document states:

The construction of dams and coastal armor structures have reduced the total sand supply to the Santa Barbara and Oceanside littoral cells by an estimated 40.4% (1,478,489 yds3/yr) and 26.0% (166,400 yds3/yr), respectively. These are significant human modifications of large natural systems, although the long-term effects of these source reductions have not yet been quantified. While there is considerable anecdotal information, as well as observations and photographic records, about shoreline erosion and coastal storm damage in both cells, there are no long-term (50 years or more) documented or published records of systematic changes in beach width or volume. Long-term changes in beach width need to be quantified, evaluated and then compared to the calculated reductions in littoral sand supply to both cells in order to confirm the correlation between the two phenomena.

A good general discussion on coastal armoring can be found on the website of the Monterey Bay National Marine Sanctuary.

The Sea Grant study mentioned above has implications for the permitting of coastal structures designed to prevent bluff retreat. See Relationship Between Bluff Erosion and Beach Sand Supply for the Oceanside Littoral Cell by Scott Ashford and Neal Driscoll of University of California, San Diego.

Here is a link to a summary of opinions by several coastal experts regarding what should be done to address coastal erosion issues along the California’s coastline. The consensus seems to be that seawalls should not be placed on eroding shorelines, so scientific information regarding erosion rates is important and that as much open space coastal properties as possible should be put into public trusts.

Public Education Program

CCC staff indicates that In addition to their website the CCC uses books (the Coastal Access Guide), brochures, signs, and maps to educate the public about erosion issues. The CCC's public education program includes presentations in schools.[9]

The website of California Ocean Protection Council provides access to a wide variety of documents relating to ocean and coastal protection, as well as a coastal geoportal that makes it easy to discover, use and distribute geospatial data layers that are relevant to the state’s coastal and marine environment. Designed for state analysts and accessible to the public, the Coastal Geoportal features an index of select data layers, a desktop viewer, and links to other online tools and resources.

An excellent article is Littoral Cells, Sand Budgets, and Beaches: Understanding California's Shoreline (October 2006).

Another useful source of information is the website of the Coastal Morphology Group at Scripps Institute of Oceanography. This site contains links to research papers on coastal erosion, sediment budgets, littoral cells, climate change, and more. See Living With Coastal Change.

Public television station KQED in San Francisco has created a great educational video Coastal Clash that explores issues surrounding coastal erosion, shoreline structures and coastal access.

The Monterey Bay National Marine Sanctuary has published a discussion of coastal armoring on their website.

A February 2010 blog post by Jim Jaffee of Surfrider Foundation is on Unplanned Beach Retreat - The Coastal Act and Seawalls.

The Ventura County chapter of Surfrider Foundation created a video called Growing the Beaches.


  1. Mark Johnsson, CCC. Surfrider 2003 State of the Beach survey response.
  2. Surfrider Foundation 2002 State of the Beach Report, state survey response.
  3. Griggs, Gary B., James E. Pepper, and Martha E. Jordan. "California's Coastal Hazards: A Critical Assessment of Existing Land-Use Policies and Practices." California Policy Seminar Report. University of California. 1992.
  4. Sterrett E.H. and R.E. Flick. "Shoreline Erosion Atlas." Shoreline Erosion Assessment and Atlas of the San Diego Region. Vol. II. Sacramento, California: California Department of Boating and Waterways. 1994.
  5. California Coastal Commission. Regional Cumulative Assessment Project: Preliminary Draft Findings and Recommendations Ð Santa Monica Mountains/Malibu Area. October 1998. p. 70.
  6. California Coastal Commission. Regional Cumulative Assessment Project: Monterey Bay Region. September 1995. Chapter 3.
  7. Surfrider Foundation 2002 State of the Beach Report, state survey response, plus personal communication from Lesley Ewing of CCC, February 7, 2003.
  8. Lesley Ewing, CCC. Surfrider State of the Beach Report survey response, January 2003.
  9. Surfrider Foundation 2002 State of the Beach Report, state survey response.

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