State of the Beach/State Reports/ME/Beach Erosion
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Less than 1% of Maine'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.
Most sandy beaches in Maine are relatively stable or are slightly eroding (<1 foot/year), while several erosional "hotspots" where erosion is greater than 2 feet/year do exist.
Maine’s coastal bluffs typically erode at an average rate of 1-3 feet/year.
The Coastal Management Plan reports that on average, the Maine coast experiences five to seven major storms per year, one tropical storm every five years, and one hurricane every 15-20 years. The current rate of sea level rise along the coast is about one inch every 12 years (eight inches per 100 years), but scientists predict that rate will accelerate in the next century if there is global warming from the greenhouse effect.
Since 1996 the Maine Geological Survey (MGS) has been conducting field studies that identify and rate coastal hazards along bluff shorelines. Eroding bluffs have been found all along Maine's coast, with most concentrated along the developed waterfront of inner coastal bays and estuaries. Casco Bay shorelines and islands with bluffs include the towns of Falmouth, Yarmouth, Freeport, Brunswick, and Harpswell. Peninsular mid-coast towns with numerous bluffs include Phippsburg, Georgetown, Westport, Friendship, and Thomaston. Beach dynamics and sand movement along the shoreline at Popham Beach State Park and Seawall Beach in Phippsburg is a continuing saga of extreme shoreline change and dune erosion. This Website looks at Seawall Beach, the Morse River, and the large sand spit (bar) connected to Seawall Beach that extends seaward of Popham Beach.
The Penobscot Bay and River region also has extensive bluffs in Castine and Bucksport. Bluff erosion affects about 10 times more shoreline than beach erosion.
Statistics compiled for the mapped region show that 53% of the Maine coast is characterized as bluff shoreline. Of this, 1.9% (40 miles) is highly unstable, 13.7% (280 miles) is unstable, and 37.5% (760 miles) is stable.
Sandy beaches along the Maine coastline are typically confined into "littoral cells", bound by rocky headlands, and comprise approximately 70 miles, or 2% of the total Maine coastline. The majority of these beaches are located in the southern portion of the state, from Portland south to Kittery. Through geophysical surveys, MGS has also determined that sandy areas along the inner shelf of the Gulf of Maine are relatively rare, occupying only 8% of the seafloor. The relative rarity of sandy beaches and sand sources in Maine make sandy areas an important natural resource. Most sandy beaches in Maine are relatively stable or are slightly eroding (<1 foot/year), while several erosional "hotspots" where erosion is greater than 2 feet/year do exist.
Camp Ellis Beach, located in Saco, Maine, is a community that faces some of the highest erosion rates along the Maine coastline. Over the last century, the erosion has pushed the shoreline back by 400 feet. Since 1968, 33 homes have been lost. The erosion along Camp Ellis is attributed to a mile-long federal jetty built in 1869 that stabilizes the northern edge of the Saco River; this jetty effectively precludes new sediment from reaching the adjacent beaches. In strong northeast storms, high water levels and large waves batter the Camp Ellis shoreline, flooding streets. The erosion is contributed to by the high reflectivity of the 1000-landwardmost feet of the jetty, which reflects waves onto the Camp Ellis shoreline. The MGS prepared a report, Variation of Beach Morphology Along the Saco Bay Littoral Cell: An Analysis of Recent Trends and Management Alternatives which discusses beach erosion and management issues facing Camp Ellis and the rest of Saco Bay. Also see here. A technical report by Peter Slovinsky of MGS Shoreline Change and Management in Saco Bay, With a Focus on Camp Ellis, Saco, Maine was presented at the 13th Biennial Coastal Zone Conference in Baltimore, Maryland in July 2003.
Shoreline change studies suggest that portions of Maine's coast face the prospect of significant coastal erosion, even without accelerated sea level rise. When sea level rise is accounted for, projected shoreline change ranges from 15 to 45 meters along bluff shorelines to 50 to 600 meters along beach and dune shorelines.
MGS has developed a scoring system to identify sections of the Maine shoreline that require beach management. The "Scoring System for Management of Maine's Sand Beaches" MGS initiated is a program that developed a model which aids the coastal planner in determining the most appropriate beach management action for different beach shorelines, based on a variety of physical, land-use, and economic criteria. The system ranks beach stretches to determine what management action (e.g., dune restoration, beach fill, or no action) would be the best alternative. The scoring system has been completed for the Saco Bay area, and is currently being developed to identify management measures along the Wells Embayment.
The source of much of the information presented above is from a series of collaborative efforts involving the Coastal Marine Geology Section of the Maine Geological Survey. Their Website has a discussion of coastal processes and hazards and summarizes past and ongoing efforts, including:
Monitoring Maine's Beaches
The University of Maine and the MGS launched a volunteer beach profiling program in 2000, monitoring changes in beach profiles monthly by ten teams of volunteers. The elevation of beaches is measured using the Emery method of beach profiling, and results are posted on the Web. The Website provides such information as the table below, and links to detailed information such as monthly profile data for each of the beaches. Seasonal changes to the beaches are being documented to understand natural cycles and volumes of erosion and accretion. Results of the profiling will be compared to coastal wave and wind data to understand how storms (northeasters, southeasters, tropical storms) affect various beaches in southern Maine. Data collected by the volunteer profiling program are typically presented and discussed at the annual State-of-Maine's Beaches conference. Besides gathering needed information, the project is building an important new constituency of beachgoers. Storm-generated bottom currents offshore of beaches are being measured with current meters placed on moorings in about 20 meters of water offshore of Old Orchard Beach and Wells Beach. Wave-orbital currents will be studied to determine the direction and relative rate of beach sand transport during storms of various types and strengths.
The table below classifies several beaches in terms of development status, replenishment history and erosional status.
Development Status of Beaches Involved
|Beach Name||Development Status||Replenishment History||Erosional Status|
|Biddeford Pool/Fortune's Rocks||medium/high||none||low/high|
MGS has received funding from the Maine Marine Research Fund to construct and use a nearshore survey system (NSS) for conducting nearshore bathymetric profiling within the surf zone. The system includes a personal watercraft outfitted with a real-time kinematic global positioning system (RTK GPS) and high-precision depth sounder in order to record bathymetric changes within the nearshore coastal marine environment. This system will permit long-shore and cross-shore imaging of the nearshore, and will be used to greatly enhance the currently limited volunteer beach profiling that only extends to the low-water mark.
MGS is also working with the Maine Coastal Program on a project entitled "Current Studies for Swim Beach Response Planning". This project, funded by MCP, entails the use of a current profiling instrument mounted on the personal watercraft NSS to monitor current patterns in the vicinity of stormwater and sewage outfalls. Detailed current measurements will be compared with meteorological conditions and water quality test results in order to develop a predictive tool for planning when swim beach water quality may be compromised due to rainfall or changes in wind directions.
Mapping Maine's Beaches
Detailed air photographs are being used to map the location of geologic environments of the Coastal Sand Dune System for use in permits for building in dune environments. The new combination of air photo-geologic maps supplements existing MGS Coastal Sand Dune Maps and will be used in the Department of Environmental Protection's permit process within the Maine Natural Resources Protection Act.
Coastal Bluff Mapping
A large portion of Maine's coast has shorelines with sedimentary bluffs, particularly in bays and estuaries. Field work of the last few years resulted in the recent release of Coastal Bluff Maps of about half of the Maine coast. These maps indicate the relative stability of bluffs for coastal planning and development near the shoreline. Field work and GIS mapping continue to increase the geographic coverage of maps in this series. A full suite of 50 color maps of Coastal Bluffs, depicting bluff stability and shoreline type, is available from the MGS. The maps use a red, yellow, green "stoplight" theme to show the condition of the bluff shoreline, in 150 feet segments of shoreline. The maps include text and photographs to describe the origin of bluffs, the chronic nature of erosion, and the variety in shoreline types in a way that can be understood by the general public.
Landslide Susceptibility Mapping
Some of Maine's coastal bluffs are susceptible to rapid slope failure in the form of slumps and slides. Landslides result in permanent loss of upland and can threaten coastal development. Work is under way to identify shoreline areas where landslides have occurred in the past and where site-specific geologic investigations are needed to evaluate future risks. This study will result in maps that complement the Coastal Bluff Maps, which can be used in coastal zone management and land-use planning. A companion series to these maps identifies landslide hazards. This map series identifies four main types of shoreline: areas where there have been landslide; areas where there are potential landslide areas (bluffs with features that might be conducive to a landslide); areas where there are bluff that are not landslide-prone; and other shorelines that are not at risk of a landslide. Characteristics and recommendations accompany each map unit.
Erosion Hazard Mapping
MGS was funded through a grant provided by SPO to map erosion hazard areas along most of the sandy beaches of Maine. The project uses both historical and short-term shoreline change data in conjunction with beach profile data to develop an average shoreline change rate. The project will result in basemaps that designate a projected 100-yr shoreline position, thus defining the expected 100-yr erosion hazard area.
Additional publications and information are also available at
The Wells Bay Regional Beach Management Plan (February 2002) includes the following findings:
- The primary source of sand to the Wells Bay Region is from offshore glacial deposits. Roughly 10% of the sand within the coastal sand dune system is located on land, with 4.2 million cubic yards in the frontal dunes and 9 million cubic yards in the back dunes. The remaining sand (135 million cubic yards) is within the submerged shore face. Thinly dispersed offshore is another 42 million cubic yards. A deposit of roughly 15 million cubic yards of sand is located offshore of Bald Head and the Ogunquit River.
- The Wells jetties have had a considerable impact on the sand budget within Wells Bay. Over 1 million cubic yards of sand has been displaced from the beach system. Between 200,000- 300,000 cubic yards of sand has accreted adjacent to the south jetty, and between 100,000- 200,000 cubic yards adjacent to the north jetty. The accretion equals about 5 acres of “new” land. The fillets of sand adjacent to each jetty appears to have stabilized and reached equilibrium with surrounding beaches. About 400,000 cubic yards of sand and gravel from harbor dredging rests on salt marsh adjacent to the harbor. Open water disposal of dredged harbor sand removed about 400,000 cubic yards from the system in the early 1960s.
A USGS report National Assessment of Shoreline Change: Historical Shoreline Change along the New England and Mid-Atlantic Coasts was released in February 2011. The New England and Mid-Atlantic shores were subdivided into a total of 10 analysis regions for the purpose of reporting regional trends in shoreline change rates. The average rate of long-term shoreline change for the New England and Mid-Atlantic coasts was -0.5 meters per year. The average rate of short-term shoreline change for the New England and Mid-Atlantic coasts was also erosional but the rate of erosion decreased in comparison to long-term rates. The net short-term rate as averaged along 17,045 transects was -0.3 meters per year.
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.
Other information sources concerning coastal erosion in Maine include:
- Coastal Erosion Mapping and Management, Special Issue #28 of the Journal for Coastal Research, 1999.
- Maine Sea Grant
Erosion Contact Info
Stephen Dickson, Marine Geologist
Peter Slovinsky, Coastal Geologist
Maine Geological Survey
Department of Conservation
22 State House Station
Augusta, ME 04333-0022
(207) 287-7173 phone
(207) 287-2353 fax
Hazard Avoidance Policies/Erosion Response
See the Erosion Response section.
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