USF researchers say Pinellas County beaches severely eroded following Hurricane Idalia

A week after Hurricane Idalia brushed Tampa Bay, the coastline is still recovering from significant erosion, prompting researchers to study the impacts.

University of South Florida geosciences professor Ping Wang has studied beach erosion for about 20 years or more, and he said the beach erosion along Pinellas County is the worst he’s seen.

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"This storm has eroded a significant amount of the dune that we have built over the last decade, two decades, three decades," explained Wang. "Yes, this is the worst I’ve seen it, partly because it comes at the wrong time."

Wang said he and a group of students are doing beach surveys every three months, focusing on the section from Sand Key all the way to Long Key. He said the erosion is worse after Idalia because the beaches were last nourished with more sand in 2018, reaching the end of their nourishment cycle. 

Researchers took before and after pictures to study erosion. This was Indian Rocks Beach before Hurricane Idalia.

Researchers took before and after pictures to study erosion. This was Indian Rocks Beach before Hurricane Idalia.

He also said they are pinpointing hotspots where parts of the beach erode faster.

"That is important because it sets up the condition that at this time some of our beaches were quite narrow before the storm," said Wang. "So if the beach is wider and higher, then it will take the wave a little bit longer to erode. This storm has like 10 hours of action, so that’s high water and big waves. So, if the beach is wide and high enough to sustain 10 hours of action, then the dune can be spared to a certain extent." 

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"If the beach is narrow and lower and cannot sustain 10 hours of action, then let’s say the beach got eroded away in about 2 to 3 hours. Then the waves start to hit the dune, and it erodes the dune away," continued Wang.

Beach erosion from Hurricane Idalia washed away a lot of sand and dunes from places like Belleair Beach, Indian Rocks Beach, Redington Beach and Sunset Beach.

Experts say this is the worst erosion they've seen on Pinellas beaches.

Experts say this is the worst erosion they've seen on Pinellas beaches.

"The aspect that stands out for this particular storm is that not only it eroded a lot of the beaches that we have, it also got to the dune," explained Wang, adding that one of the saddest parts has been watching a dune grow for decades for it to be eroded in hours.

He said healthy dunes help protect infrastructure but take a long time to grow. So, his research group is looking at how the storm impacted the coast and what can be done to make beaches wider.

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"Like how much would we expect the beach change after a storm, before storm or during regular tide so that information can help for example the Corps, or the state or the county to design the nourishment," said Wang.

A Pinellas County government spokesperson said workers are still analyzing the beach erosion. They said it’s a priority to keep the beaches nourished to protect the barrier islands, and they are working with federal, state and municipal authorities to get that done.

Pinellas CountyHurricane IdaliaUniversity of South Florida