The Lake Erie Coastal
Erosion Problem in Ohio
Coastal Erosion in Ohio
Coastal erosion doesn’t happen only along the east and west coasts of the United States. Because most of us live where the earth is stable, many people are surprised to learn that there are settings in Ohio where land can disappear rapidly. The following points address some misconceptions about coastal erosion in Ohio.
Coastal erosion isn’t a new problem. William W. Mather, Ohio’s first state geologist, noted in 1838 that certain portions of the coast had lost 130 feet over the previous 42 years. And geologist Charles Whittlesey wrote in 1867 that on the Cleveland waterfront between 1796 and 1842 “there had been a general encroachment of two hundred and five feet.”
Coastal erosion isn’t a rare problem. Of the thousands of Ohio homes on the Lake Erie waterfront, nearly half are within 50 feet of the top of the bluff and a quarter are within 25 feet of the top of the bluff. Many were further from the bluff when they were built.
Coastal erosion doesn’t affect only lakefront landowners. All Ohio taxpayers are affected because the State is the largest landowner along the Ohio shoreline. Public parks, swimmers, boaters, anglers, utilities and infrastructure are all subject to the costs and damage of coastal erosion. Reduced property tax revenues and increased insurance costs are borne by many, even those who don’t live on the coast. The economic losses caused by coastal erosion can exceed tens of millions of dollars.
Coastal erosion isn’t always slow. Erosion rates have been as high as 110 feet per year.
Coastal erosion can be dangerous. In Ohio, three fatalities in recent decades are known to have resulted when eroded shoreline materials collapsed suddenly.
Good, fact-based information on the severity of erosion in a particular area can be hard to find. The ODNR Division of Geological Survey has studied Lake Erie coastal erosion for decades. We have the best information on where coastal erosion is occurring in Ohio and why. The following discussion addresses why the Ohio coast is eroding and what information is available about it.
The Erosion Problem
Erosion begins with Lake Erie waves. Storm waves are the most destructive, pounding against the shoreline and breaking down the materials that make up the shore. Where the shore is a low bank, it can be washed away entirely or become flooded. Waves weaken the base of a higher clay shoreline until the base of the bluff—the slope that rises from the shore to where the upper land flattens out—washes away or collapses. When deprived of its natural base, the bluff becomes overly steep, standing at an unstable angle that it cannot sustain. It responds by slumping, or settling down to a more natural, stable angle. The settling can be sudden or gradual, but as the slope settles, the top of the bluff moves farther from the shoreline. The following, simplified drawings illustrate this process.
Even a rocky shore is vulnerable to wave attack. Rather than softening and washing away, the toe of a rocky bluff gradually crumbles as waves cut a notch into the bluff base. Eventually the notch erodes far enough into the rock that the upper portion of the bluff, now unsupported, suddenly collapses. This takes much longer than the failure of a clay bluff—maybe years—but the collapse is sudden and can occur with little warning. Natural cracks in the rock accelerate the process.
For actual photographs of the results of some of these processes, see the photos page.
These forms of erosion tend to be episodic. A bluff may appear stable, losing only a few feet over many decades and giving an impression of permanence. Then suddenly, perhaps during a storm, several feet can collapse in a few hours.Whether the bluff is clay soil or shale bedrock, several stories high or low enough to step over, the result of erosion is that the top of the bluff—perhaps the edge of someone’s back yard—recedes farther inland.
Waves are only one factor in erosion. Groundwater seepage, freeze-thaw cycles, and lake ice also contribute. Lake levels, which determine how high up the bluff waves can reach, can increase erosion rates as they rise or decrease them as they fall. (Read more about lake levels here.) In addition, the natural beaches that once protected the shore from wave attack are mostly gone, with 44% of the shoreline having no beach at all.
Because waves and gravity never cease, erosion cannot truly be stopped. Seawalls, breakwalls and other structures can buy time, but any structure needs ongoing maintenance to stay effective and maintenance is expensive. Many landowners find erosion occurs more quickly than they can raise the funds to control it.
The issues surrounding coastal erosion are complex: What causes erosion at a particular property? What are the most effective measures to prevent it and what other effects will those measures have? How much will such measures cost and how do property owners pay for them? There is no single answer for all properties, but an important starting point is knowing how quickly a shoreline is eroding. The Coastal Erosion Area program was conceived to help landowners, local planners, lenders, real estate professionals and others make wise decisions regarding shoreline recession by actually measuring the amount of erosion that occurs.
Last update January 18, 2011