When does investing in a jetty make sense? We love the new sand, but it’s a band-aid solution at best. From DredgingToday.com: The U.S. Army Corps of Engineers Philadelphia District pumped 667,000 cubic yards of sand onto the beach at Brigantine, NJ.
This project was completed last month. The $15.7 million program was awarded in September for both Brigantine and Ocean City, said Army Corps of Engineers spokesman Steve Rochette. The federal government is picking up 65 percent of the cost, with the state Department of Environmental Protection funding 26.75 percent and the municipalities 8.25 percent.
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Things that need to be considered when talking “beach jetties”
Natural Flow
Erosion is a natural part of the cycle of the beach. The natural flow of water deposits sand at times and then removes it at other times. During the cycle the beach may have a great deal of sand or very little, but over time it balances out. Humans desire to eliminate the part of the cycle with erosion control. Jetties interrupt the natural flow of water and sand in an attempt to control erosion with corresponding effects.
Accumulation
One effect from the erection of jetties for erosion control is the accumulation of sand and sediment behind the jetty. The jetty prevents the natural flow of water and the sand and sediment that are carried with the flow cannot get past the structure. This accumulation reverses erosion and provides extra sand for the beaches behind the jetty. This accumulation creates unintended consequences for other beaches.
Downdrift
While jetties accumulate sand on the updrift side, the opposite effect occurs on the downdrift side. The jetty causes erosion due to the lack of sand which is caught on the other side. The solution is to erect another jetty, but the process never ends. Eventually there will be a last jetty and the beach and land on its downdrift side will suffer the consequences of erosion. Jetties built to control erosion end up causing it. This effect is the reason for jetties no longer being a preferred method of erosion control.