“Beach replenishment” is the one step forward, two steps back method of keeping pace with rising sea levels along populated coasts: where sand is pumped onto beaches to build up naturally receding dunes and upper shore reaches weakened by development.
One of the draws of this method is that it is increasingly costly as sand itself becomes more scarce and must be sourced from further out; the resulting steep floor lines created by select area dumping on parts of beaches often increase existing rates of erosion. Artificially jacked up areas already erode more than twice as fast as naturally-packed sediment and this combination of factors is leading experts to predict a time in the very near future when replenishing, for many areas, will no longer be an option—leaving our coastal communities at the mercy of climbing tides.
Since 1985, 80 million cubic yards of sand had been applied on 54 of the state’s 97 miles of developed coastline: a truckload of sand for every foot of beach. Estimates are that this work cost more than $800 million –before adjusting for inflation. –Marine Geology professor at New Jersey’s Stockton College, Stewart C. Farrell said in this article.
The state of New Jersey has long led the way in coastal maintenance—with a series of replenishments, rock jetties and seawalls (two other methods of coast conservation that are more harsh on surrounding environments and no more permanent as solutions than beach replenishment). However, following Hurricane Sandy and the subsequent depletion of existing sand there, scientists are warning that the practice will soon be unfeasible—too costly or physically impossible to carry through. Advocates are pushing for the development of new innovations to combat the issue. (NY Times)
“Offshore sand, high-quality sand, is a highly finite resource,” said S. Jeffress Williams, a coastal scientist with the United States Geological Survey and the University of Hawaii.