Lake Erie Beaches and Sand Resources
Beaches are temporary geologic features that are found where land and water meet. They are composed of an accumulation of plant, animal, shell and rock fragments, ranging in size from fine sand to large boulders.
Beaches are usually thought of as one of the most attractive elements for shoreline recreation. They also serve as a first line of defense against erosion damage, protecting the land and infrastructure landward of the beach from wearing away.
Beaches as Places to Play
Information about all of Ohio's Lake Erie beaches and public access sites are found in Ohio's Lake Erie Public Access Guide - Coast Edition. The 169 sites are also included in the Lake Erie Public Access Map Viewer.
Beaches as Erosion Control Structures
Beaches create an buffer between the lake and the upland. A beach that is relatively stable or growing provides natural protection to the land behind it. When the beach area shrinks, there is increased danger of property damage as the water line advances inland. This inward movement of the shoreline is called erosion. Larger beaches are able to protect against the effects of wave action better than narrow ones.
Beach nourishment is considered a “soft” erosion control measure that involves the placement of sand within the shore and nearshore zones to build-up beach thickness and width from shore to lake. Beach nourishment is explained in detail in the erosion control methods Web pages.
Additional information in the Lake Erie Shore Erosion Management Plan discusses the sand resources available along each reach of Ohio's shore.
Natural forces formed and continue to shape Lake Erie (see LELPC 2). It is these natural forces, wind, waves and energy, that move beach material and give beaches a dynamic quality in that the rock fragments that compose beaches are always in motion.
Movement of beach material may be parallel to land, away from land or toward land. Beach material moves as waves advance and recede. It is this movement of beach material that can take sand from where people would like to be and place it where people do not want it such as in the harbor channel entrance.
Information in Chapter 11 of the Ohio Coastal Atlas Second Edition explains how Ohio's sand resources have changed over time.
(from pages 188-190 of the Ohio Coastal Atlas Second Edition, 2007)
Sand and gravel occur along the Ohio lakeshore as beaches and nearshore deposits. Beaches are typically less than 25-feet wide, except where sand and gravel are trapped by shore structures, harbor structures and natural promontories. In these areas, beach deposits may be 1,500-feet wide.
Nearshore deposits of sand and gravel typically extend less than 1,000-feet offshore. However, updrift of large harbor structures, sandy may extend several thousand feet offshore. At the lakeward boundary of the deposits, the sand and gravel thin to expose the underlying clay or rock or the sands are mixed with fine grained, open lake sediments.
Nearshore bars may be present along some reaches of the lake. Typically there are one or two poorly to moderately defined nearshore bars (1 to 2 and 3 to 4 feet of relief between trough and crest of the bar). However, in areas with larger volumes of sand and gravel, three or more moderately to well-defined bars (relief greater than 5 feet) may be present. In places, clay or rock may be exposed in the trough or nearshore bars.
On wide beaches, sand dunes may develop at the back of the beach. Dunes develop where wind-blown sand accumulates beyond the reach of normal wave activity. For much of the lakeshore, this occurs only where the beach is more than 45-feet wide. Sediment in the dunes is typically fine or very fine sand. Sand dunes serve as a reservoir of sand. During periods of erosion, sand eroded from the dune nourishes the beach.
Changes in Beaches Since the 1870s
When settlers first came along the Ohio shore in 1796, Lake Erie’s beach east of Cleveland had been used as a road for many years (Whittlesey, 1838). Since then, Ohio’s beaches have changed dramatically. Many reaches of the lakeshore east of Cleveland lack beaches. Much of this change is linked to manmade alterations along the shore.
By the 1820s, construction of jetties and breakwaters built to create harbors at stream mouths, impounded beach sediment on the structures’ updrift side, disrupting the longshore transport of sand and causing beach erosion downdrift of the harbors.
Even during the low-water years of the mid-1930s, beaches along many reaches of shore were narrower and more segmented than the beaches of the 1870s. As erosion of sand from beaches reduced the width of beaches, shore erosion also increased. This is because for most areas, the volume of sand contributed by erosion of bluff materials did not compensate for the volume of materials impounded by structures or eroded from the beach. This trend continues today, aggravated by armoring of the lakeshore to prevent erosion.
Littoral Transport of Sand and Gravel
Waves are the principal agent eroding sand and gravel from beaches. During a storm, several feet of sand may be eroded from a beach, creating a wave-cut scarp several feet high. Under calmer conditions, waves deposit sand and gravel on the beach to restore the beach profile.
Erosion of sand and gravel from beaches is cyclical. During periods of low wave energy, sand and gravel are deposited on the beach, and winds may blow sand into the back beach. During periods of high wave energy, the beach and dune may be eroded. Erosion of the dune supplies sand to the beach during periods of erosion. Sand and gravel are carried alongshore to downdrift beaches and offshore, where they are deposited in nearshore bars.
Sand and gravel move along the shore in response to waves and currents. This movement is called littoral transport. As waves break along the shore, sand and gravel are moved up and down the beach face in a zigzag pattern. The more obliquely waves approach the shore, the more rapidly sediment is transported.
Direction of littoral transport varies over seasons, years and decades in response to changes in the frequency and direction of winds blowing across the lake. Changes in lake level and ice cover may also be significant factors in determining direction of net transport over time.
The net direction of sediment transport can be inferred from the accumulation of sand and gravel next to groins, docks, channel jetties and harbor breakwaters. A map of net sediment transport based upon these accumulations of sand and gravel shows that net littoral transport is generally eastward along the shore east of Avon Point and westward along the shore west of Avon Point.
East of Avon Point, eastward transport by waves generated by prevailing westerly winds exceeds westward transport by waves generated by northeast storm winds. West of Avon Point, westward transport by waves generated by northeast storm winds exceeds easterly transport by waves generated by prevailing westerly winds.
Littoral transport along the shore west of Avon Point is further subdivided by several areas of converging and diverging littoral transport. A zone of convergence occurs at the mouth of Sandusky Bay where sand is carried northwestward along Cedar Point and southward along Bay Point. Another convergence occurs at Port Clinton and a zone of divergence occurs at Locust Point.
Sources of Sand and Gravel
Sand and gravel found along the lakeshore represent the coarse fraction of sediment eroded from rock and clay deposits found in inland areas, in bluffs along the lakeshore, and in the nearshore. Sand and gravel (the coarse-fraction) from inland areas are transported primarily as bedload along the bottom of the stream or river, while silt and clay (the fine fraction) are carried in suspension. At the stream mouth, stream currents slow, depositing sand and gravel near the stream mouth. From there, the sand and gravel are redistributed by waves to form beaches and nearshore deposits. The fine fraction remains in suspension and is carried into the lake where much of the silt and some of the clay settle out.
Erosion of the lake shore contributes sand and gravel directly to the littoral system. Where the shore is composed of sand or rock, all of the eroded materials may be retained in the littoral system. Where the bluff is composed of glacial lake sediments or till, only part of the sediment is coarse enough to remain in the littoral system. Glacial lake sediments typically contain 2 to 5 percent sand-sized sediment and are not significant sources of sand and gravel. Glacial till typically contains up to 20 percent sand and gravel. Where the bluff is composed of glacial lake sediments or till, only part of the sediment is coarse enough to remain in the littoral system. Along the lakeshore east of Avon point, there are numerous stretches where sand and gravel occur in the upper bluff. Nearly all of the sand and gravel eroded from these deposits is retained in the littoral system.
Bedrock found along the lakeshore from Huron eastward is shale, with the exception of one short outcrop of sandstone on the east side of Vermilion. Shale is composed of consolidated silt and clay, and as the shale erodes, it typically breaks down into particles of many sizes. In some case, the particles are large slabs up to a foot thick and several feet across. In other cases, the particles are gravel or sand size. The shale may also disaggregate into the original silt- and clay-sized particles. Thus, only a portion of the eroded shale particles are coarse enough to remain in the littoral system, and eventually these are worn away by harder particles.
Bedrock found in the island area of Lake Erie is limestone and dolostone. As these rocks erode, they typically break up into sand-to boulder-size pieces. Limestone and dolostone are more resistant to abrasion than shale and last considerably longer on a beach.
The volume of sand and gravel supplied to the lake by rivers and by erosion of the shore and nearshore has changed dramatically since Ohio was settled. Damming of streams, mining of sand and gravel from streams, and dredging of navigation channels at the mouths of streams, impounds or captures sand and gravel before they reach the littoral system. Except perhaps at the Chagrin River, probably little bedload carried by streams now reaches Lake Erie.
Shore Protection’s Impact
Shore protection has also reduced erosion rates and the volume of sand supplied to the littoral system. For the shore between Sandusky and Conneaut, estimates of sand and gravel annually supplied to the littoral system by shore erosion range from 138,000 cubic yards between 1876-1973 (Carter, 1977) to 205,000 cubic yards between 1876-1990 (Mackey, 1995). These volumes are based on recession of the shore over the respective time periods. However, with ever-longer reaches of the lakeshore being armored, the recession is decreasing.
From the 1870s to the 1970s, shore protection increased gradually. During and following the record-high lake levels of the 1970s to the 1990s, the rate of armoring accelerated. Now seawalls and revetments alone protect about 50 percent of the shore east of Sandusky (Gerke and Fuller, 2004), reducing the potential source area of sand and gravel by about 50 percent.
The nearshore remains a source of sand and gravel. However, the volume of sand and gravel eroded in the nearshore is relatively small compared to the volumes contributed by streams or eroded from the lake bluffs. Between 1876 and 1973, the volume of sand and gravel supplied to the littoral system along the mainland counties by erosion of the nearshore was approximately 26,587 cubic yards per year (Carter, 1977). This volume of sand and gravel is inadequate to maintain beaches along the lakeshore. Furthermore, erosion of the cohesive nearshore materials (glaciolacustrine sediments and till), a process called downcutting, steepens the nearshore profile and allows larger waves to come closer to shore. This exposes shore protection structures to greater wave energy.
Human Impact on Sand and Gravel Resources
Urbanization of Ohio’s lakeshore has had significant impacts on sand and gravel resources. The first major impact was the development of harbors at the mouths of major rivers. By the 1820s, short jetties had been constructed at most harbors to keep sand and gravel out of the channels. Over time, these jetties were extended to deeper water as sand built up on the updrift side of the harbor. At some harbors, construction of jetties was followed by construction of large breakwater complexes extending up to a mile offshore. These structures form major barriers to littoral transport of sand and gravel. For example, at Fairport Harbor, about 7 million cubic yards of sand have been impounded (U.S. Army Corps of Engineers, 1976). This volume of sand is equivalent to what would be found in a beach 14 miles long and 50 feet wide.
An additional impact of harbors has been open-lake disposal of sand and gravel dredged from navigation channels in the harbors. As most of the sand and gravel dredged found in the outer (lakeward) part of harbors is littoral sediment, open-lake deep-water disposal of the sediment permanently removes it from the littoral system. Sand and gravel found at the upstream ends of some navigation channels is bedload sediment that would eventually have reached the littoral system were it not for dredging the navigation channel.
Mining sand and gravel from beaches has adverse impacts on the beach. Once a common practice, it is now discouraged. Likewise, grooming a beach to remove large stones removes coarser sediment that provides natural protection for the beach during storms. If stones are collected as the beach is groomed, they should be buried in the beach where they will be reworked by storm waves. Removing sand dunes to provide an unobstructed view of the lake also has adverse impacts on the beach because removing the dune removes the reservoir of sand that maintains the beach during periods of erosion.
Shore protection structures have significant impacts on beaches. As noted above, one impact is to cut off a potential source of beach building sediment. Nourishing the littoral system with a volume of sand and gravel comparable to what will be impounded by the structure and/or what would be introduced by erosion of shore materials over the life of the structure would help mitigate some of the structure’s impacts on littoral sand resources.
Shore protection structures, such as groins and breakwaters, provide protection by trapping sand to form a beach. However, these structures typically trap more sand along a given stretch of shore than would normally occur along that stretch. As a result, the beach and shore downdrift of the structure may experience an incremental increase in erosion.
Beach and shore erosion have been documented by numerous studies and observed by numerous property owners. Less obvious is loss of sand and gravel from Ohio’s nearshore. Comparing sediment surveys made in the 1870s, 1950s and the 1990s documents the loss of sand and gravel from nearshore areas.
Mitigating Human Impacts on Sand Resources
Sand and gravel dredged from numerous small marinas’ channels is bypassed annually or semiannually. The volumes involved are typically less than 2,000 cubic yards per marina, although at Mentor Harbor up to 20,000 cubic yards may be bypassed. Sand and gravel dredged from federally maintained harbors has not been regularly bypassed for several reasons: pollution, economics and equipment. Unfortunately, the volume of sediment tends to be much larger (25,000 to 40,000 cubic yards) and the impacts much greater.
Failure to bypass sand and gravel has a significant long-lasting impact on the beach and nearshore. If 40,000 cubic yards of sand and gravel dredged from a channel are placed in deep water, it may take years to decades for natural erosion to replenish this littoral sediment. Along the Central Basin shore, replenishment may take several years, but in the Western Basin, replenishment may take 30 to 40 years. If open-lake disposal of sand occurs several years in a row, replenishing the sand may take a decade to more than a century.
Since 2001, sand has been bypassed at two federal harbors. In 2001 and 2002, 40,000 and 60,000 cubic yards of sand, respectively, dredged from the lake approach channel at Fairport Harbor were placed nearshore at Painesville on the Lake (Guy and Liebenthal, 2003). In 2004, about 75,000 cubic yards of sand dredged from Conneaut Harbor were placed along the shore east of Conneaut.
Mitigating part of the impact of shore protection structures on sand resources can be accomplished by nourishing the littoral system with sand from upland or open-lake sites. Where the shore is armored to prevent erosion, the impacts of reduced erosion on sediment supply can be mitigated by nourishing the littoral system with a volume of sand comparable to what would have been supplied to the littoral system had shore protection not been constructed. These volumes can be calculated using bluff height, bluff composition, and historical recession rates. Where shore protection structures will trap sand, the beach can be prefilled with sand obtained offsite. These volumes can be calculated using nearshore water depths, morphology of the existing beach, and historical changes in beaches at the site. Prefilling the beach reduces the volume of littoral sediment trapped by the structure helping maintain littoral transport of sediment to downdrift beaches.
Sources of Sand to Restore Ohio Beaches
Potential sources of sand and gravel to nourish and restore Ohio’s beach and nearshore areas include sand and gravel dredged from deep water deposits, sand mined from upland deposits, and sand dredged from channels. A new source of beach sediment is shell fragments of zebra and quagga mussels.
Sand and gravel deposits found offshore of the Lorain-Vermilion area and offshore of Fairport Harbor have been dredged commercially for many years. Commercial dredging areas occupy just part of these large deposits. Approximately 41.8 million cubic yards of fine to coarse sand occur offshore of the Lorain-Vermilion area, and 191 million cubic yards of fine to medium sand occur offshore of Fairport Harbor (Williams and others, 1980). These deposits are far enough from shore and in deep enough water that there is likely no exchange of sand with the littoral system.
Sand mined from upland deposits could be used in some locations. However, upland deposits, particularly sand dunes, may be too fine for beach nourishment. In addition, upland deposits are being depleted and/or covered by urban development.
Recovering sand dredged from other harbor areas is a ready source of beach nourishment material. Sand dredged from the upper reaches of harbor channels may or may not be suitable for beach nourishment. At Fairport Harbor, sand and gravel dredged from the upper reach of the harbor was suitable for nearshore disposal and was placed in the nearshore at Painesville. At Cleveland, contaminants in sand and gravel from the upper channel make it unsuited for direct placement in the littoral system. However, when the sediment is transferred into the confined disposal facility, the hydraulic transfer process segregates the sand from the finer grained sediment. Segregation and cleaning of the sand and gravel by this process may provide an opportunity to recover materials for beach nourishment.
In recent years, the shells of the invasive zebra mussels and quagga mussels have become a significant constituent of beach sand along the lakeshore. Along portions of rock-bound shore such as around the island area and near Huron, shell material may make up the entire sand fraction. Along the Western Basin, shell material may comprise 50 percent of the sand. Along the Central Basin, shell material is present in smaller concentrations but still represents a significant constituent of beach sand. If these invasive mussels have one benefit to the Ohio lakeshore, it may be providing beach building material to replace that lost by human activities.
Ohio Coastal Management Document (3.96 MB pdf ) see:
Policy 21: Lakeshore Recreation and Access (p160)
Poicy 22: Lake Erie Beaches and Public Bathing (p.165)
Ohio Coastal Atlas Chapter 11 - Coastal Engineering
Ohio Coastal Design Manual
Lake Erie Shore Erosion Management Plan
Lake Erie Literacy Principle 2: Natural forces formed and continue to shape Lake Erie and its watershed
Ohio's Lake Erie Public Access Guide - Coast Edition