Replenishment also eliminates sandbars that would normally reduce wave energy farther offshore, says John Weber, mid-Atlantic regional manager for Surfrider Foundation, an environmental group. Between the steeper slopes and fewer sandbars some of the waves breaking near shore are packing a heavier punch. "A beach that is replenished is potentially more dangerous than a natural beach," Weber adds.
There have been no studies to date on the link between beach replenishment and spinal injuries, but when one looks at some of the beaches that have undergone replenishment (aka “renourishment”) projects, there is often a spike in "major medical" injuries—or those requiring emergency medical services—that same year or the following year, according to data reported to the United States Lifesaving Association (USLA).
Take Ocean City, which the U.S. Army Corps of Engineers says was replenished in 2006. There were 87 major medical injuries that summer, according to USLA data. The following year there were 345. After a second replenishment project in 2010 injuries rose from 233 to 306 the following year. In Cape May, which the Corps confirms was replenished in 2007, injuries rose from 12 that year to 35 in 2008, according to the USLA. After a second replenishment in 2009 injuries rose from 35 in 2008 to 41 that summer and reached the same total in 2010. Following a third replenishment in 2012 injuries rose from 15 in 2011 to 45 that year.
Cape May's numbers were so high in 2008 that the late Sen. Frank Lautenberg (D–N.J.) asked the Corps to investigate a potential correlation between spinal injuries and beach replenishment. The Army never completed the study because they said they don't need to—they did not believe there was a link. "We don't have any data showing us a correlation or relationship between beach nourishment and spinal injuries," says Edward Voigt, chief of public and legislative affairs in the Corps's Philadelphia office. "If someone had information like that—not anecdotal but some kind of data or analysis, with actual facts associated with it—that would give us something to look at."
Whereas Voigt acknowledges beach replenishment can result in steep drop-offs near the shore, they don't necessarily result in injuries, he says. "There are so many factors that come into play with injuries: Was it high tide? Low tide? What time of year was it? Were there storms? Was there an increased use of the beach? A lot of things can affect injuries," he notes.
Indeed, that's exactly what Cowan and his team are trying to figure out. So far, their research has yielded a few discoveries: Most injuries occurred on days when the waves were 0.45 to 0.75 meters high. And those hurt were often bathers—not surfers—standing in less than knee-deep water with their backs to the ocean when they were suddenly knocked down by a wave and slammed into the sand. "We want to create an algorithm using a series of environmental factors so that we can predict in real time whether it's more dangerous to go in the water," Cowan says.
The idea is compelling enough that when Cowan spoke at a conference recently, representatives from the National Weather Service approached him to see if they could join forces to come up with a "surf zone injury" forecast, not unlike a weather forecast.
What Cowan's research has not conclusively determined is whether spinal injuries are the result of beach replenishment. "Everyone has an opinion about why they're happening," Cowan says. "I'm not able to say why."