Shore Protection

Wrightsville Beach, NC; Waves hammer a berm formed by erosion from the heavy winds and roughs waters brought on by Hurricane Ophelia.

 

Beach Nourishment

Beach nourishment is the adding of sediment onto or directly adjacent to an eroding beach. This "soft structural" response allows sand to shift and move with waves and currents. Dune restoration is commonly carried out during a beach nourishment project as well.

A wide, nourished beach system absorbs wave energy, protects upland areas from flooding, and mitigates erosion. The beach provides a buffer between storm waves and landward areas, and it can prevent destructive waves from reaching the dunes and upland developments. When sediment is naturally moved offshore from a nourished beach, it causes waves to break farther from the shoreline, which weakens their energy before reaching the shore.

Before a project can be implemented, however, project designers must determine the necessary amount of sand to nourish the beach. Engineers develop sediment budgets, which do not involve monetary figures but rather inflows and outflows of sediment in a given coastal system.

Once a sediment budget has been calculated, sources must be found to provide the needed sediment. Beach fill material must closely match the sand on the native beach so that when waves and currents naturally distribute the fill, most of it remains on the beach and is not swept offshore. Concurrently, fill material must usually be of a texture acceptable for beach-goers.

Beach nourishment projects must be supplemented with additional quantities of sand to counteract the natural removal of sediment by waves and currents. This periodic renourishment is calculated in sediment budgets, and it results in the placement of sand at a project location usually every few years.

To learn more about how beach nourishment supports coastal storm protection, see How Beach Nourishment Projects Work. (pdf, 2.54 MB)



Reviewed 18 Jan 2013

Beach Nourishment

Beach Nourishment
Source: U.S. Army Corps of Engineers

Beach Nourishment

In 1956 the Corps was authorized to carry out beach nourishment for shoreline protection. Since then, the Corps has participated in beach nourishment projects on approximately 350 miles of shoreline, mostly on the Atlantic and Gulf coasts of the United States.