Today, we’re taking a closer look at the formation and importance of coastal dunes, ongoing threats, and efforts to grow and stabilize them.
Prior to Hurricane Frederic’s landfall in 1979, long-time residents Mike Aymond and Terry Preston recalled large formations in the mainly undeveloped areas.
“At that time, you wouldn’t see the Gulf or the Sound in many cases, or the bay, on either side as you drove down because the dunes were so large,” said Aymond.
“The dunes, especially down Fort Pickens Road, were huge; I mean two, three, four stories high, beautiful. It was amazing,” added Preston.
Dr. Phillip Schmutz is an expert in coastal geomorphology, focusing on the formation of dunes.
“Two main factors are vegetation, coastal vegetation and wind,” said Schmutz, an assistant professor in the University of West Florida Department of Earth and Environmental Sciences.
“So, as wind blows across the beach, it picks up and moves that sand and that vegetation traps that sediment and that’s what grows the dune landscape over time.”
For dunes flattened by hurricanes such as Frederic in 1979, Opal in 1995, and Ivan in 2004, Schmutz says researchers estimate about a decade for them to regenerate, particularly here on the Gulf coast.
“It takes about 8-10 years to get back to pre-storm conditions, if you don’t completely alter and change the environment in itself,” explained Schmutz. He added that about two years is needed to just to ‘jump-start’ the system. “And, most of that early two years, 1-2 years, you need that “vegetation” to regrow back up.”
It is extensive, deep-rooted vegetation in dunes that has been a factor in helping those old, remnant formations along the coast survive the storms and continue to thrive.
“Like the Cross right there within Pensacola Beach,” cited Schmutz as a first example. “There are sections of the National seashore between Pensacola Beach and Navarre that have large dunes, particularly on the Sound side – not so much on the ocean/gulf side.”
Further toward Fort Walton Beach, the UWF researcher points to a few fairly large dunes on Eglin property and within the state park area between Destin and Ft. Walton.
As for whether the dunes and the extensive dune system along certain stretches of the beach would ever regain their pre-Frederic size, Dr. Schmutz says probably not.
“I personally don’t see, at least on Pensacola Beach, with the exception of maybe going multiple decades of growth in time to get back to those 20-plus foot size dunes.”
During his four years of study locally, Schmutz has found that current conditions don’t support the growth of really large dunes here – at least not anymore.
“Part of that is our normal year-to-year, month-to-month climate, and part of that is also our storm activity,” Schmutz explained of the effect of more frequent storm activity due to climate change. “Yes, it’s been 15 years since a direct hit in (the) Pensacola Beach area, but we have had some storms, even in the last three years that have had some pretty good modification impact on our dunes.”
Another factor related to dune restoration and growth is human impact or development.
Dr. Schmutz and his students recently completed research on the impact of asphalt and gravel left over from Hurricane Ivan’s destruction of the road, J. Earle Bowden Way (SR 399), between Pensacola Beach and Navarre Beach.
As part of the study, they removed some of the road fragments and left some in a large area.
“We looked at how much sediment is moving over the course of a few months. And, we found that that lag, that asphalt material has a substantial (statistically significant), so substantial impact on sediment transport, which is required and needed for dune growth,” said Schmutz of their study results.
“It seems strange that with all the years that Pensacola Beach has been in its phases of development and redevelopment, that beach nourishment only became a concept in the early 2000s,” said Paolo Ghio, director of development and environmental services and executive director of the Santa Rosa Island Authority, referencing the first nourishment project on Pensacola Beach dating back to 2002.
The process involved the dredging and pumping of new sand onto an 8.3-mile stretch of the beach and included the restoration of dunes, in that order.
“When you come back and you start laying down new beach, you’re also picking up those dunes that got eroded and you are reinforcing the ones that are left over,” explained Ghio. “It’s not enough just to place sand on them. If you’re smart, and we are because we’ve learned how to do it properly, you’re vegetating them and you’re putting up sand fencing.”
Renourishment was required after Hurricane Ivan’s 2004 landfall and most recently in 2016, after a series of smaller storms eroded the coastline. The consensus now is that it should be planned about once every 10 years, unless precipitated by a hurricane.
A crucial part of the beach nourishment process today, dune restoration was the primary focus of coastal recovery efforts in past decades.
Current coastal management efforts, in conjunction with the Florida Department of Environmental Protection, include dune restoration as needed, dune walkovers and signs to keep people off. According to Ghio, it’s a strategy that appears to be working.
“First of all, the beach is doing terrific. It is strong. It is wide. It is healthy," Ghio began his assessment. "The dunes, especially the primary dune, I can’t remember it being this robust and consistent.”
He maintains that keeping the dunes healthy - for habitat and people –is well worth it.
“For one, they (dunes) are our first barrier of defense against a strong storm surge. But, they are a feature. They are what the residents, the community, the tourists look to. It’s an icon, one of the many icons that define Pensacola Beach.”
Pensacola Beach is a big part of the tourism industry locally. According to Visit Pensacola, more than 2.3 million visitors came to Escambia County last year and spent nearly $840 million dollars.