Coastal erosion is the process by which local sea level rise, strong wave action, and coastal flooding wear down or carry away rocks, soils, and/or sands along the coast. All coastlines are affected by storms and other natural events that cause erosion.
In the United States, coastal erosion is responsible for roughly $500 million per year in coastal property loss, including damage to structures and loss of land. To mitigate coastal erosion, the federal government spends an average of $150 million every year on beach nourishment and other shoreline erosion control measures.1 In addition to beach erosion, more than 80,000 acres of coastal wetlands are lost annually—the equivalent of seven football fields disappearing every hour of every day.
Sedimentation refers to the process where solid particles settle down at the bottom of a liquid, or sometimes the accumulation of particles by the action of wind or water. Sedimentation can occur in bodies of water such as rivers, lakes, and oceans, where particles carried by the water settle due to gravity. Since floodwaters carry large amounts of sediments, they will alter the landscape and create new landforms. This will result in changing the course of rivers and altering the shape of floodplains.