Beach nourishment (also referred to as beach renourishment, beach replenishment, or sand replenishment) describes a process by which sediment, usually sand, lost through longshore drift or erosion is replaced from other sources. A wider beach can reduce storm damage to coastal structures by dissipating energy across the surf zone, protecting upland structures and infrastructure from storm surges, tsunamis and unusually high tides. Beach nourishment is typically part of a larger integrated coastal zone management aimed at coastal defense. Nourishment is typically a repetitive process since it does not remove the physical forces that cause erosion but simply mitigates their effects. The first nourishment project in the United States was at Coney Island, New York in 1922 and 1923. It is now a common shore protection measure used by public and private entities. History The first nourishment project in the U.S. was constructed at Coney Island, New York in 1922–1923. Before the 1970s, nourishment involved directly placing sand on the beach and dunes. Since then more shoreface nourishments have been carried out, which rely on the forces of the wind, waves and tides to further distribute the sand along the shore and onto the beaches and dunes. The number and size of nourishment projects has increased significantly due to population growth and projected relative sea-level rise. Erosion Beach erosion is a specific subset of coastal erosion, which in turn is a type of bioerosion which alters coastal geography through beach morphodynamics. There are numerous incidences of modern recession of beaches, mainly due to longshore drift and coastal development hazards. Causes of erosion Beaches can erode naturally or due to human impact (beach theft/sand mining). Erosion is a natural response to storm activity. During storms, sand from the visible beach submerges to form sand bars that protect the beach. Submersion is only part of the cycle. During calm weather smaller waves return sand from bars to the visible beach surface in a process called accretion. Some beaches do not have enough sand available to coastal processes to respond naturally to storms. When not enough sand is available, the beach cannot recover following storms. Many areas of high erosion are due to human activities. Reasons can include: seawalls locking up sand dunes, coastal structures like ports and harbors that prevent longshore transport, dams and other river management structures. Continuous, long-term renourishment efforts, especially in cuspate-cape coastlines, can play a role in longshore transport