Experts warn: Beach renourishments usually come with rip current risk
A restored Panama City Beach, with its signature parallel sand bars, will pose a continued danger to swimmers from rip currents created when wave action traps water inshore of the underwater ridges, which then breaks free in the form of the powerful outflowing current.
PANAMA CITY BEACH – The good news comes with a warning.
For the fifth time in 20 years, plans are under way for a beach renourishment project along the 18.5-mile city and Bay County beachfront to cure erosion caused by Hurricane Michael.
While there is universal support within the county tourism industry to bring the sandy beach back up to its pre-storm condition, safety experts warn that the restoration itself will also set the stage for continued rip current emergencies like the ones that helped claim a record number of swimming deaths this year.
The Bay County Tourist Development Council, which manages beach renourishment, anticipates dredging 1.2 million cubic yards of sand from a “borrow area” several miles south of Shell Island that will be distributed via a hopper dredge along the shoreline from St. Andrews State Park to the Walton County line. Once permitting is complete and funding is in hand, the $15 million project is expected to begin in early 2020.
The county has renourished the beach four other times in recent history. The largest project occurred in 1998-99 when 9.8 million cubic yards of sand were put down along the entire beachfront; in 2005-06, following serious erosion from Hurricane Ivan, dredging deployed another 3.3 million cubic yards; in 2011, a partial renourishment added 1.3 million cubic yards at the east and west ends of the beach, and in 2017, a limited project restored four one-mile segments of beach including the city and county pier areas.
TDC spokeswoman Lacee Rudd declined to provide details about the 2020 project, citing its pending status. However, the Bay County Long-Term Recovery Plan approved by the county in August included a proposed beach renourishment effort of 1.2 million cubic yards that would cost $15 million. The county plans to seek funding from the Corps of Engineers, FEMA, the state Department of Environmental Protection, along with TDC funds set aside for such projects.
While dredging sand to replace shoreline eroded by hurricanes and other conditions remains the preferred method of the U.S. Army Corps of Engineers, several experts have cautioned that the restoration effort reinforces environmental conditions that spawn dangerous rip currents. A restored Panama City Beach, with its signature parallel sand bars, will pose a continued danger to swimmers from rip currents created when wave action traps water inshore of the underwater ridges, which then breaks free in the form of the powerful outflowing current.
“When you put sand on the beach, it isn’t stable,” said Dr. John Fletemeyer, a national expert on rip currents who founded Florida’s Aquatic Law and Safety Institute and is Co-director of the International Rip Current Symposium. “When it goes back in the water, it creates the sandbars. You will have more rip currents and stronger ones as a consequence of beach renourishment.”
In a 2017 column in The Journal of Coastal Research, Fletemeyer and three colleagues cited a growing body of evidence that drownings and other aquatic accidents – such as diving mishaps leading to serious injury – spike at beaches that have recently undergone renourishment.
In one example, Ocean City, Maryland, saw such incidents jump from 87 in 2005 to 346 the following year after a renourishment project. A second renourishment four years later in 2010 saw another sharp increase, from 233 before the dredging to 306 afterwards. In another example, Fletemeyer and colleagues John Hearin, Brian Haus and Andrea Sullivan cited Delray Beach, Florida, where days with rip current sightings over a 100-day period went from three prior to renourishment in 2008 to 22 afterwards.
The scientists caution that other factors might be at play, including an increase in tourists using a beach that has been restored to a pristine state. They argue for more research to confirm a growing amount of anecdotal evidence.
Fletemeyer told The News Herald that with the overall economic impact of ocean beaches estimated at $1.2 trillion, including $41 billion in Florida, it is certain that sand nourishment programs will continue. What is essential, he added, is that localities recognize the inexorable connection between a beach that has been returned to its pristine state, and the potential for rip current dangers that comes with the restored underwater landscape.
“When you have sand bars, you have rip currents,” Fletemeyer said.