Beach renourishment, also called beach recovery or replenishment, is the act of rebuilding eroded beaches with offshore sand and gravel that is dredged from the sea floor. Renourishment projects are sometimes implemented to widen a beach for more recreational capacity, or to save structures built on an eroding sandy shoreline. The process is one that requires ongoing maintenance; the shoreline created by a renourished beach will eventually erode again. According to the National Oceanic and Atmospheric Administration (NOAA), the estimated cost of long-term restoration of a beach is between $3.3 and $17.5 million per mile.
The process itself involves dredging sand from an offshore site and pumping it onto the beach. The sand "borrow" or dredging site must also be carefully selected to minimize any negative environmental impact. Dredging can stir up silt and bottom sediment and cut off oxygen and light to marine flora and fauna .
Under the Energy and Water Development Appropriations Act of 2002, 65% of beach renourishment costs are paid for with federal funds, and the remaining 35% with state and local monies. Beach renourishment programs are often part of a state's coastal zone management program. In some cases, state and local government work with the U.S. Army Corp of Engineers to evaluate and implement an erosion control program such as beach renourishment.
Environmentalists argue that renourishment is for the benefit of commercial and private development, not for the benefit of the beach. Erosion is a natural process governed by weather and sea changes, and critics charge that tampering with it can permanently alter the ecosystem of the area in addition to threatening endangered sea turtle and seabird nesting habitats.
In some cases, it is the coastal development that brings about the need for costly renourishment projects. Coastal development can hasten the erosion of beaches, displacing dunes and disrupting beach grasses and other natural barriers. Other human constructions, such as sea walls and other armoring, can also alter the shoreline.
Results of a U.S. Army Corps of Engineers Study completed in 2001—the Biological Monitoring Program for Beach Nourishment Operations in Northern New Jersey (Manasquan Inlet to Asbury Park Section)—found that although dredging in the borrow area had a negative impact on local marine life, most species had fully recovered within 24–30 months. Further studies are needed to determine the full long-range impact of beach renourishment programs on biodiversity and local coastal habitats.
[Paula Anne Ford-Martin ]
U.S. Army Corp of Engineers, Engineer Research and Development Center. The New York District's Biological Monitoring Program for the Atlantic Coast of New Jersey, Asbury Park to Manasquan Section Beach Erosion Control Project Final Report, 2001.
U.S. Department of Commerce, National Oceanic & Atmospheric Administration, National Ocean Service, Office of Ocean & Coastal Resource Management. "State, Territory, and Commonwealth Beach Nourishment Programs: A National Overview." OCRM Program Policy Series Technical Document No. 00-01 (March 2000).
National Oceanic & Atmospheric Administration, Coastal Services Center. Beach Renourishment in the Southeast http://www.csc.noaa.gov/opis/html/beach.htm. Accessed June 5, 2002.