State of the Beach/State Reports/FL/Beach Erosion
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Florida has extensive data regarding the rates of beach erosion along its coastline.
Approximately 5% of Florida's shoreline is critically eroding, according to the report "State Coastal Program Effectiveness in Protecting Natural Beaches, Dunes, Bluffs, and Rock Shores" (T. Bernd-Cohen and M. Gordon), Coastal Management 27:187-217, 1999.
According to the Coastal Hazards section of Florida's 2010 FACT report:
The length of critically eroded beach has increased a net total of 70.7 miles from 327.9 miles in 2000 to 398.6 miles in 2010. The length of noncritically eroded beach has decreased a total of 12.1 miles from 107.7 in 2000 to 95.9 in 2010. Overall, the total length of eroded beaches—critical and noncritical combined—increased by 58.6 miles. Of the 825 miles of sandy beaches in Florida, 494.5 miles are considered either critically or noncritically eroded.
Florida identifies and maps critical erosion areas. "Critically eroded" is defined as "a segment of shoreline where natural processes or human activities have caused or contributed to erosion and recession of the coastal system to such a degree that upland development, recreation, wildlife habitat, or important cultural resources are threatened or lost." Critical erosion areas may also include peripheral segments or gaps between identified critical erosion areas which, although they may be stable or slightly erosional now, their inclusion is necessary for continuity of management of the coastal system or for the design integrity of adjacent beach management projects.(Florida Department of Environmental Protection, 2001). Florida also distinguishes between coastal erosion and beach erosion.
Erosion data is compiled and stored by the Coastal Data and Analysis Section, Bureau of Beaches and Coastal Systems (BBCS), Florida Department of Environmental Protection (FDEP). General reference websites are here and here. The data are available online here and here and are updated regularly through DEP monitoring, local government project monitoring and annual critical erosion updates. 
In 1998 the definition of "critical erosion" was expanded to include threats to existing development or recreational interests, and threats to, or loss of, wildlife habitat or important cultural resources. The updated (June 2012) Critical Erosion Areas Report includes tables with listings of the erosion areas for the 35 coastal counties, along with maps of erosion areas for most of the coastal counties.
Another rich source of information regarding coastal erosion, beach fill project monitoring, storm surge research reports, aerial photographs on inlets and more is the Beaches and Shores Research Center at Florida State University.
Shoreline Change Rate Estimates for Florida’s counties are available online. The county reports prove that Florida’s shoreline is very mobile and large accretion and large erosion events can occur along the same sections of beach over time. Beach fill is common along the shores making present erosion rates difficult to determine.
An analysis of Walton County historic shoreline data show a very mildly eroding shoreline, between +0.5 and -0.5 ft/year. -1.0 ft/year is used for planning purposes. Bay County average erosion rates are estimated to be between -0.5 ft/year and +0.5 ft/year. Duval County erosion events vary. The shoreline south of St. Johns River entrance has an average erosion rate of -5.5 ft/year. Flagler County has an average erosion rate of -1.0 ft/year. Sections of Santa Rosa and Escambia Counties have erosion rates of -1 ft/year to -9 ft/year. Sections of Franklin County have average erosion rates up -9 ft/year. Most of Gulf County is experiencing accretion but some sections have average erosion rates up to -43 ft/year. Areas in Nassau County have erosion rates up to -17 ft/year. Okaloosa County’s coastal erosion rates are generally -1 ft/year. There are sections that have erosion rates up to -8.5 ft/year. St. Johns erosion rates are generally considered stable. Volusia County has an average erosion rate of -1 ft/year.
A 1999 mapping project done by the Federal Emergency Management Administration concluded that in Brevard County the average erosion rate is 6.6 ft/year, in Escambia County the average erosion rate is 4.3 ft/year, and in Lee County the average erosion rate is 30 ft/year.
According to the 2000 FACT report, Florida's coastline is extremely vulnerable to a range of natural hazards. The most serious and continuous threat is that posed by hurricanes and tropical storm events. As a result of Hurricane Andrew in 1992, 43 people were killed and damages amounted to $25 billion. Florida uses the Sea, Lake and Overland Surges from Hurricanes (SLOSH) numerical computer model for predicting storm surge inundation zones and estimating the vulnerability of each zone to flooding.
The 2000 FACT report provides estimates of the number of people per county and percent of county population in the storm surge zones. For example, in Dade County 272,000 people (12% of the residents) are in the storm surge zone. According to the 2000 FACT report, 10 counties have over 50% of their population in the most highly vulnerable area, the storm surge zones. In three counties this value is over 70%. A survey suggests that public awareness of the level of risk is high for 59% of the population, the rest having moderate to low understanding. While perhaps not directly relevant to the beach health indicators, this is a good example of the sort of information that can be developed to support decision-making.
The 2000 FACT report notes that erosion can significantly reduce the amount of beach available for public use. Beaches that have lost much of their sand offer less space for recreation, public facilities become more vulnerable to destruction, and the beach is visually less appealing. Erosion can also destroy structures built along the coast. When sand and sand dunes are washed away, so is the protection they provide for buildings built on the coast. Eroding beaches also mean less habitat for species of animals and plants that are dependent upon the dunes and beaches.
The BBCS conducted beach profile studies and concluded that from 1989 to 1993 the amount of eroding shoreline in Florida increased from 332 to 356 miles. This change is a 7% increase over five years. The study divided eroding shoreline into critically and non-critically eroding areas. Critically eroding areas have structures threatened by erosion. Non-critical erosion does not affect man-made structures. During the same period, critically eroding areas increased from 218 to 233 miles, and non-critically eroding areas extended from 115 to 123 miles.
The BBCS determined that from 1993 to 2000 the amount of eroding shoreline in Florida increased from 356 to 448.7 miles. The latest estimate (August 2003) of the amount of eroding shoreline is 433.8 miles. This huge increase can be largely attributed to the major storms of 1994, 1995, 1998, and 1999, which altered Florida's shoreline. The 2000 erosion list includes 327.9 miles of critical beach erosion, 9.1 miles of critical inlet shoreline erosion, 108 miles of non-critical beach erosion, and 3.7 miles of non-critical inlet shoreline erosion.
As of the 2000 FACT report, more than 75% of Florida's shoreline was identified as critically eroding. All beaches defined as critically eroding areas are under a beach maintenance program, which typically involves restoration and re-fill.
The 2004 hurricane season was the most active storm season since 1851. The hurricanes of 2004 did unprecedented damage to much of Florida's 800 miles of sandy beaches. They reshaped long stretches on both coasts, worsened already serious erosion, erased tens of millions of dollars worth of recent beach rebuilding and destroyed or seriously damaged some 2,000 seaside buildings. Interestingly, little erosion was noted in areas that still have natural, undeveloped beaches, such as along Juno Beach and elsewhere in north Palm Beach County and at Canaveral National Seashore. The vegetation and natural features, such as sand dunes, allow such beaches to survive the poundings of storms, according to the Florida Department of Environmental Protection.
Hurricanes Frances and Jeanne in September 2004 caused an estimated $127 million worth of damage to county-owned property along the Treasure Coast. At Wabasso Beach Park, the storms left in a heap of splintered wood the part of the restrooms, lifeguard station and boardwalk they didn't sweep away to the sea, and even broke off the eastern end of the access road. A $1 million project to replace the boardwalk, restrooms, lifeguard station and picnic pavilion and add piling foundations for the restrooms was expected to be put out for bid in January 2007.
Erosion problems continued in several locations during the winter of 2004-2005, including in New Smyrna Beach, where beachside motels and condominiums suffered damage, seawalls collapsed and a gazebo at a beach boardwalk park fell.
There was an early start to the hurricane season in 2005, with Hurricane Dennis slamming the Florida panhandle on July 10. Dunes vanished on St. George Island and in Walton County the foundations of condominiums and homes were left hanging over the edge of a cliff 20 feet above the beach. In response, some communities requested that they be allowed to "scrape" the beach (push sand from the beach back to what's remaining of the dunes), but in some cases this can accelerate erosion and the scraping must be timed to not interfere with sea turtle nesting. State environmental secretary Colleen Castille was quoted as saying that she was pushing for emergency authorization to expand and accelerate beach fill projects.
Substantial coastal erosion occurred in many areas along the Atlantic coast of Florida in May 2007 when an early tropical storm brought large waves. This prompted calls for emergency funding for beach fill or other shoreline protection projects. The state issued an emergency order following the storm to speed repairs to erosion-battered protective structures along a section of St. Johns County and five other stretches of Florida beaches. The state Department of Environmental Protection said the order was designed to expedite permitting for repairs in the aftermath of Subtropical Storm Andrea. It allowed local governments and property owners to seek emergency permits for armoring, reinforcement of foundations, placing of sandbags and construction of protective berms and walls. The 30-day emergency declaration covered a 10,000-foot stretch of St. Johns County flanked by the Guana River State Park, as well as segments of beach in Volusia and Palm Beach counties.
The Cape San Blas area has long been a high erosion location. A news story in May 2012 stated that Cape San Blas lighthouse was being threatened by erosion and would have to be moved soon.
The following discussion is from Why Restore Eroded Beaches? on the FDEP website:
"Beach erosion threatens the very resource that residents and visitors enjoy. Over 409 miles, or approximately 50% of the state's beaches, are experiencing erosion. At present, about 299 of the state's 825 miles of sandy beaches are experiencing "critical erosion", a level of erosion which threatens substantial development, recreational, cultural, or environmental interests. While some of this erosion is due to natural forces and imprudent coastal development, a significant amount of coastal erosion in Florida is directly attributable to the construction and maintenance of navigation inlets. (emphasis added) Florida has over 60 inlets around the state, many have been artificially deepened to accommodate commercial and recreational vessels and employ jetties to prevent sand from filling in the channels. A by-product of this practice is that the jetties and the inlet channels have interrupted the natural flow of sand along the beach causing an accumulation of sand in the inlet channel and at the jetty on one side of the inlet, and a loss of sand to the beaches on the other side of the inlet."
The beaches and coastal systems publications page provides access to general publications (including coastal control line publications, vegetation and dune line publications, and even PowerPoint™ presentations) and technical reports (including the most up-to-date critical erosion reports and maps, shoreline change estimate reports, and historic shoreline change reports). Another key link is Beaches and Coastal Systems Data.
Additional data is available via the Geology and GIS pages of the FDEP Website:
The good source of coastal erosion information and information on beach fill projects is the Beaches and Shores Resource Center at Florida State University.
The Coastal and Marine Geology Program of the U.S. Geological Survey has generated a comprehensive database of digital vector shorelines and shoreline change rates for the U.S. Southeast Atlantic Coast (Florida, Georgia, South Carolina, North Carolina). These data were compiled as part of the U.S. Geological Survey's National Assessment of Shoreline Change Project.
National Assessment Of Shoreline Change: Part 2, Historical Shoreline Changes And Associated Coastal Land Loss Along The U.S. Southeast Atlantic Coast (2005) states:
- "Land losses on the east coast of Florida are primarily associated with erosion of sandy beaches and barrier islands, especially around inlets (Clark, 1990) where swift tidal currents easily remove the loose sand that forms the ends of the barriers. Land loss along the lagoon shores generally is minor because these water bodies are narrow or are already protected by erosion control structures such as bulkheads. Wakes generated by boats in the lagoons, such as along the Intracoastal Waterway, can contribute to local bank erosion in some areas.
- Compared to historical shoreline changes in the other Southeast Atlantic states, the average long-term change rate of 0.2 ± 0.6 m/yr for east Florida was low, primarily because tidal and wave energy were low and beach nourishment projects were common where erosion persisted. Even though long-term erosion rates were generally low (average is -0.5 m/yr), at least 39% of the Atlantic shoreline experienced long-term erosion. The highest long-term rates of erosion were observed at the southern end of Amelia Island on the margin of Nassau Sound, and relatively high rates of erosion persisted along the northern end of Jupiter Island at Jupiter Inlet. Long-term and short-term trends and rates of shoreline change were similar, such as around Cape Canaveral, where there was apparently little or no alteration of the sediment supply. Slow but chronic erosion along the east coast of Florida eventually results in narrowing of the state’s valuable recreational beaches, and many highly developed beaches have no dunes to protect buildings from large storm waves and flooding. Consequently, beach nourishment is commonly used to mitigate the effects of long-term erosion. Short-term shoreline stability or accretion increased where beach nourishment was common, such as along Miami Beach and Jacksonville Beach.
- The Florida Department of Environmental Protection Bureau of Beaches and Coastal Systems reports that much of the east coast of Florida is undergoing critical erosion. Their definition of critical erosion is based on the vulnerability of resources to erosion rather than on the rate of erosion; therefore, even low rates of erosion would be critical in most areas of economic development."
The analogous document for west coast of Florida is the USGS report National Assessment Of Shoreline Change: Part 1, Historical Shoreline Changes And Associated Coastal Land Loss Along The U.S. Gulf Of Mexico (2004), which states:
- "Land losses for west Florida are primarily associated with erosion of sandy beaches and barrier islands, especially around inlets (Clark, 1991) where swift tidal currents easily remove the loose sand that forms the ends of the barriers. Land loss in the bays and lagoons of west Florida is minor because these water bodies are generally small or are already protected by erosion control structures such as bulkheads (Doyle and others, 1984).
- Compared to shoreline erosion in some other Gulf Coast states, the average long-term erosion rate of -0.8 ± 0.9 m/yr for west Florida is low, primarily because wave energy is low. Even though erosion rates are generally low, more than 50% of the shoreline is experiencing both long-term and short-term erosion. The highest rates of erosion in west Florida are typically located near tidal inlets. Long-term and short-term trends and rates of shoreline change are similar where there has been little or no alteration of the sediment supply or littoral system (see Dog Island, St. George Island, and St. Joseph Peninsula). Conversely, trends and rates of change have shifted from long-term erosion to short-term stability or accretion where beach nourishment is common (see Longboat Key, Anna Maria Island, Sand Key, and Clearwater, Panama City Beach, and Perdido Key). A shift from long-term relative stability to short-term erosion occurred on Santa Rosa Island, probably as a result of beach erosion and overwash deposition associated with Hurricane Opal in October 1995.
- Slow but chronic erosion along the west coast of Florida eventually results in narrowing of the Stateʼs valuable recreational beaches, and many highly developed beaches retain no dunes to protect buildings from large storm waves and flooding. Lighthouse Point, south of Tallahassee, presents a good example. Situated in the low energy sector of the coast, past storms have still destroyed park facilities and some roads that are now protected by rock revetments. In places where beach erosion is chronic, these structures have replaced the beaches except where artificially nourished."
The Florida Sea Grant website is another source of information.
The Heinz Center's Evaluation of Erosion Hazards, conducted for the Federal Emergency Management Agency (FEMA), studied the causes of coastal erosion hazards and proposed a variety of national and regional responses. The study, published in April 2000, concentrates on the economic impacts of erosion response policies as well as the cost of erosion itself to homeowners, businesses, and governmental entities.
A NOAA website that has graphs of sea level data for many coastal locations around the country over the last 40 to 50 years and projections into the future is Sea Levels Online.
NOAA Shoreline Website is a comprehensive guide to national shoreline data and terms and is the first site to allow vector shoreline data from NOAA and other federal agencies to be conveniently accessed and compared in one place. Supporting context is also included via frequently asked questions, common uses of shoreline data, shoreline terms, and references. Many NOAA branches and offices have a stake in developing shoreline data, but this is the first-ever NOAA Website to provide access to all NOAA shorelines, plus data from other federal agencies. The site is a culmination of efforts of NOAA and several offices within NOS (including NOAA’s Coastal Services Center, National Geodetic Survey, Office of Coast Survey, Special Projects Office, and Office of Ocean and Coastal Resource Management) and other federal agencies to provide coastal resource managers with accurate and useful shoreline data.
A related site launched in 2008 is NOAA Coastal Services Center's Digital Coast, which can be used to address timely coastal issues, including land use, coastal conservation, hazards, marine spatial planning, and climate change. One of the goals behind the creation of the Digital Coast was to unify groups that might not otherwise work together. This partnership network is building not only a website, but also a strong collaboration of coastal professionals intent on addressing coastal resource management needs. Website content is provided by numerous organizations, but all must meet the site’s quality and applicability standards. More recently, NOAA Coastal Services Center has developed a Sea Level Rise and Coastal Flooding Impacts Viewer as part of its Digital Coast website. Being able to visualize potential impacts from sea level rise is a powerful teaching and planning tool, and the Sea Level Rise Viewer brings this capability to coastal communities. A slider bar is used to show how various levels of sea level rise will impact coastal communities. Completed areas include Mississippi, Alabama, Texas, Florida, and Georgia, with additional coastal counties to be added in the near future. Visuals and the accompanying data and information cover sea level rise inundation, uncertainty, flood frequency, marsh impacts, and socioeconomics.
Erosion Contact Info
Department of Environmental Protection
Marjory Stoneman Douglas Building
3900 Commonwealth Boulevard
Tallahassee, FL 32399-3000
Hazard Avoidance Policies/Erosion Response
- Roxane Dow, DEP. Surfrider State of the Beach Survey response, December 2003.
|State of the Beach Report: Florida