Beach nourishment

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 coastal defense scheme. 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 1922–23. It is now a common shore protection measure utilized by public and private entities.

Nourishment is one of three commonly accepted methods for protecting shorelines. The structural alternative involves constructing a seawall, revetment, groyne or breakwater. Alternatively, with managed retreat the shoreline is left to erode, while relocating buildings and infrastructure further inland. Nourishment gained popularity because it preserved beach resources and avoided the negative effects of hard structures. Instead, nourishment creates a “soft” (i.e., non-permanent) structure by creating a larger sand reservoir, pushing the shoreline seaward.

Beaches can erode both naturally and due to human impacts (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.

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Wikipedia