Coastal Erosions

A beach is simply a gently sloping, narrow strip of land which generally borders on the sea, a lake, or other body of water. Beach materials such as pebbles, stones, sands, and shells cover most beaches. Most beaches are created through natural weathering and eroding over hundreds to thousands of years. Other beach materials can be manmade. In general, manmade beach stuff is manmade from chemicals and saltwater solutions.


Sand is used to help create a smooth, flat beach. Sand is one of the most important beach building supplies as it acts as a smoothing agent. Because of its nature, sand grain is not fine enough to roll easily, so it has to be shot or rolled using a roller. Rolling the sand into the beach proper requires a shovel or sloped beach implement (a sand dune raker). A flat beach knife or roller provides more traction. There are also mechanical “rollers” which operate in a similar fashion.

Waves can cause damage to beaches by breaking them up and making them swell. Waves may be caused by wind or swell caused by cold fronts or high tides. Cold fronts can cause the beach to become too dry and slick for walking or surfing, so a water sprinkler system may be effective in removing excess dryness. High tides may cause surf to be pushed onto the beach. This can further increase the potential for larger and stronger waves to break up the sand.

Seawalls may be built to prevent erosion or to reduce wave impacts. Some beaches have seawalls which extend for at least several hundred meters, protecting people from the direct impact of waves and snow. Other beaches have seawalls which only extend to a few hundred meters, allowing a limited amount of inlet water but denying surf access.

Coastal erosion is another problem caused by changing climates. Lying directly upon the beach, concrete, wood, plastic, or anything else used to build the beach, can erode away over time. Sand dunes can form behind shoreline houses, blocking people’s access to the beach. Other forms of erosion include softening of the underlying ground material through processes such as river run off, or beach washing. In addition, changing temperatures and rising or falling water levels can cause sediment – either from gravel or from sand – to erode away from the beach.

Storm surges and increasing water levels brought about by tropical storms and hurricane force winds can erode beaches and create hazards for people. This may occur when high tides are combined with strong winds. When this happens, waves may come in and wash debris toward the beach. Other times, when low tide combined with high winds does not dissipate the surge enough to allow beach access, walls of water may build up between the beach and the shoreline. When a large storm surges across the United States, many beaches become devastated by these devastating waves, sometimes leaving just a few shells on the shore.