Hurricane Helene's storm surge, nearly a month ago, eroded practically all the coastal dunes along Pinellas County's coast, according to University of South Florida researchers.
USF geosciences professor Ping Wang and his students took measurements of the dunes using GPS coordinates to map them.
Wang says Helene was the strongest storm to impact Pinellas in 80 years with storm surge over two feet higher than previously recorded at Clearwater Beach and St. Pete Beach.
Helene brought up to 18 feet of waves at the mouth of Tampa Bay, less than 10 miles from the shoreline. The storm surge also overtopped the Gulf-side seawall by up to two feet and bayside seawall by over four feet. This allowed high waves to break over land, causing sand to wash onto streets and houses, plus structural damage.
These same coastal areas were relatively spared two weeks later by Hurricane Milton. WUSF's Jessica Meszaros spoke to Wang at Madeira Beach about a week after Helene came through.
Where are we standing right now?
We're standing at Madeira Beach, just to the north of Johns pass, and looking at the erosion by the storm. At this particular side, what's standing out is all the debris that get washed onto the beach and also all the sand that get washed into the backyard and the people's house, underneath the house and onto the street.
And have you ever seen anything like this before?
Not along this coast, not along Pinellas County coast. We also did study after Hurricane Ian down Fort Myers, and that's actually worse in terms of structural damage. Beach erosion-wise, I don't think it's any worse than us, simply because the beach over down the south Fort Myers and Naples are quite different. Our Beach is we have a wider, taller beach with a higher sand dunes.
I mean, we went all the way from Clearwater, all the way down. Our beach used to have lots of those sand dunes. That's about the only sand dune that we got left. And all the sand dunes got eroded away.
I was walking around the beach earlier; you can see the roots sticking out of the sand. We can tell where the dune used to be. But we also come out, my group also come out, here every three months and work with the Pinellas County to study the beach changes.
When you find out about how the sand has moved around, and what does that tell you about the health of the beach?
Well, the health of a beach, for example, at this particular place, we would have a beach, then we will have a sand dune. So right now, what storm does is it levels the beach… makes the beach a much lower elevation that dune was, whatever that's left this particular location, and I expect some leftover dune. Then some places the dunes were much higher. And so, the dune it's part of the beach system. You have a sandy beach, you have dune, and it's part of the ecosystem or human system, and it's completely destroyed [by] this particular storm.
And once you have collected all of this data, what can be done with that data? How can you use it for the future?
Well, it helps us to understand how the beach behaves. And so how can we manage, how can we manage the beach and dune and sea wall, and also the resiliency of the buildings.
And can you talk through real quick, just like, what you and your students do, like out here, what tools you're using and what methods you're using for surveying, if it's talking to people or just physically measuring.
Today was mostly just a recon. So, we brought the GPS that we can use the GPS to do survey, and we didn't bring any other equipment. And talking to people is very interesting. So, we spent all day walking up down the beach.
This part, you have a wide beach… when we go up north, there's no beach. So, we actually walk on people's sea wall. And surprisingly, we're just on the other side, the bay side… and the people are like, surprisingly kind. We are kind of intruding onto their property. They're busy fixing things. We're walking along the wall.
People are very nice, and so far, I only have one person tell me to get off the wall because of safety reasons, and they would … come and talk to us about their experience. And surprisingly, many people is looking into the positive side of this, like, 'Okay, it could be worse. We can have this fixed,” although their door gets blown out and there's sand in their house and the garage. There's the spirit is something I experienced pleasantly.
