Evaluation of Inlet Bypassing on the Atlantic Coast of Florida, U.S.A.

Houston, J.R., 2026. Evaluation of inlet bypassing on the Atlantic coast of Florida, U.S.A. Journal of Coastal Research, 42(3), 385–402. Charlotte (North Carolina), ISSN 0749-0208. The Atlantic coast of Florida in the United States stretches nearly 600 km. It features 18 inlets, 16 of which have been modified to benefit navigation. Eleven of the 16 were created by cutting through barrier islands. From as early as the late 1800s at a few locations and as late as the early 1970s, these inlets caused an average shoreline recession of 67 m on adjacent shorelines by removing sand from the littoral system through impounding it on updrift shorelines or depositing it in ebb and flood shoals or navigation channels. From the 1970s/1980s to the 2020s, averaging about 43 years, the erosive effects of the inlets on adjacent shorelines were largely mitigated by placing sand on affected shores, resulting in an average shoreline advance of 32 m. The mitigation involved traditional inlet sand bypassing, where sand is dredged from updrift shorelines, shoals, or navigation channels and moved past the inlet to affected shores. Mitigation also included the placement of sand from offshore or inland sources to move shorelines seaward and enhance storm protection and recreation. Although often called beach nourishment, if sand is placed specifically to counteract shoreline recession caused by inlets, it qualifies as a form of sand bypassing. Approximately halfway through this 40-year mitigation period, Florida established a formal program that used only traditional inlet sand bypassing to address shoreline recession caused by inlets. The effectiveness of various methods to mitigate the erosive effects of modified inlets on adjacent shorelines is assessed. Most inlets in the United States, including those along the Florida Atlantic coast, have been modified for navigation, so Florida's experiences in managing inlet effects may be broadly applicable. [ABSTRACT FROM AUTHOR]