State of the Beach/State Reports/OH/Beach Erosion
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Erosion along the Ohio shore of Lake Erie is a serious problem, especially in areas of high bluffs
and erodible sand, clay and till. The two primary erosional processes are wave erosion and mass
wasting. Natural factors such as beach distribution, near shore depths, storm frequency, lake
level, and shoreline orientation contribute to variations in rates of erosion over time and place to
place. Erosion control structures and offshore disposal of sand dredged from harbors also
contribute to variations and have exacerbated erosion problems in some areas. Recession rates
vary from nominal along dolomite and limestone island areas to as much as 12 feet annually in
portions of Lake and Ashtabula counties. Of the 312 miles of shoreline, approximately 157
miles, or 50 percent, are eroding at a rate greater than 0.3 foot per year. Localized areas of accretion can occur updrift of shoreline structures. One such area is at Conneaut Harbor in Ashtabula County, where a growing sandbar has turned from a nuisance to a tourist attraction.
Erosion along the Ohio Lake Erie shore is a major geologic hazard that has significantly affected coastal residents. Erosion occurs as a result of the removal of material at the base of a bluff by wave action and the combined effects of gravity and groundwater, which erode the bluff face by slumping or debris flows or both. In areas of exposed bedrock, undercutting at the base of the bluff causes catastrophic failure and collapse of the bluff face into the lake. The rate at which the shore erodes is a function of the geologic composition of the shore, lake levels, prevailing winds, and the presence or absence of shore protection.
Shore erosion along Lake Erie can be either dramatic or relatively steady in nature. Between 1973 and 1990, the average shore recession rate was 1.41 feet per year, or approximately 24 feet over the 17-year period. Recession rates along the coast range from 0 feet per year to up to 56 feet per year along certain reaches of the coast. Large-scale changes can also occur. Near Painesville, Ohio, the coast has undergone between 34 and 207 feet of recession from 1973 and 1990. The Sheldon Marsh barrier beach, which was overwashed and eroded during the great November 1972 storm (Carter, 1973), has undergone between 268 and 953 feet of recession over the 17-year time period. While these large-scale changes are very dramatic, relatively steady erosion rates along the coast are also a hazard, eroding bluffs and damaging properties. As a bluff recedes, buildings are lost by either falling into the lake, or being torn down before they are destroyed, or moved back from the bluff.
Ohio Coastal Management Program & Final EIS Part II (March 1997) states:
"ODNR's Division of Geological Survey studied shore erosion in the eight Ohio counties bordering Lake Erie. Field studies and office studies examined the physical setting (e.g.,shore stratigraphy, shore relief, shore orientation, beach width, nearshore slopes, nearshore sediment, wave climate) and the cultural setting (e.g., land use, shore protection structures) that influence the rate of recession, both through time and along shore. In addition, recession-line maps were prepared using charts from 1876-1877, aerial photographs from the late 1930s and aerial photographs from 1973. These recession-line maps are perhaps the most important aspect of the shore erosion studies because they show how the rate of shore recession changes through time and along shore. By relating these temporal and geographic changes in recession rates to changes observed in the physical and cultural setting, many of the temporal and geographic changes in shore recession can be explained.
As part of the OCMP, an updated recession line map will be used to designate Lake Erie coastal erosion areas. This map, like its predecessor, will also be used to study how changes in the physical and cultural setting affect recession rates. Using information from the earlier study and from the mapping done to designate Lake Erie coastal erosion areas, the State of Ohio will continue to assess the effects of shore erosion and to evaluate techniques for mitigating erosion and restoring areas adversely affected by erosion.
Additional studies of coastal erosion along the Ohio shore of Lake Erie are being conducted under a five-year (1991-1996) cooperative agreement between ODNR's Division of Geological Survey and the U.S. Geological Survey. A major thrust of the study will be to develop a sediment budget for the Ohio lakeshore by tying together many aspects of the geologic framework and coastal processes. Detailed maps of bluff stratigraphy, surficial sediment and subsurface sediment will provide a better picture of the type of sediment introduced to the lake each year and how it is dispersed. Detailed recession-line maps, building on mapping done to designate Lake Erie coastal erosion areas, will be used to better determine how much sediment is annually introduced to the lake.
The results of this five-year study will directly benefit the OCMP, in part by improving the knowledge base used to determine whether and how to mitigate site-specific erosion problems.
In addition to conducting and participating in shore erosion studies, the State of Ohio also cooperates closely with the U.S. Army Corps of Engineers (COE) on erosion control projects such as Section 103 Small Beach Erosion Projects, Section 111 Mitigation Studies, and other specifically authorized projects. Close cooperation and coordination between ODNR and COE will assure that these projects are consistent with the OCMP."
The USGS, working in cooperation with the Ohio Department of Natural Resources (ODNR), Division of Geological Survey, conducted a 5-year study to document historic erosion of Ohio's shoreline bluffs and to determine what natural processes and human activities are contributing to the erosion of the shoreline.
Since 1988, ODNR has mapped Ohio’s Lake Erie coast to identify coastal erosion areas—land along the coast that is projected to be lost to erosion over the next 30 years if no measures are taken to address it. For the 2010 coastal erosion area map update, the amount of recession that occurred between 1990 and 2004 was measured. Based on the amount of recession that occurred between those years, calculations were made to project recession rates for the next 30 years. Areas projected to erode more than 11 feet are included in the 2010 designated coastal erosion areas and are shown as such on the 2010 coastal erosion maps. See Internet Map Site. In December 2010 ODNR Division of Geological Survey finalized updated maps that document Lake Erie coastal recession in Ohio and designate coastal erosion areas, which include coastal land that is projected to be lost to erosion over the next 30 years if no action is taken. Recession rates were based on the amount of recession from 1994 to 2004.
On January 4, 2010, ODNR mailed letters to property owners and local jurisdictions (counties, municipalities and townships) included in the preliminary 2010 coastal erosion area designations. Courtesy letters were also mailed to property owners who were included in the 1998 Coastal Erosion Area, but are not included in the 2010 Coastal Erosion Area Preliminary Designation.
Also see Division of Shore Erosion Publications.
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
Hazard Avoidance Policies/Erosion Response
See the Erosion Response section.
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