“A 500-year flood event.”
That’s how scientists and Florida Gov. Ron DeSantis are referring to the record amount of water left stirring in Hurricane Ian’s wake.
A look at new satellite imagery before and after the storm shows why: Rivers, lakes and streams on both sides of the state were overflowing after the historic hurricane, with some areas seeing up to 20 inches of rain in just one day.
Now, state water managers tasked with overseeing water resources for millions of Floridians are facing the aftermath of unprecedented flooding. Some of the state’s most iconic rivers — and the communities surrounding them — were inundated: the Peace River in Arcadia, the St. Johns River on the Atlantic Coast and the Kissimmee River feeding into Lake Okeechobee.
“Hurricane Ian’s intense flooding across Florida is indicative of what we’ll see more of in the future,” said Ken Graham, director of the National Weather Service, in a statement.
“Climate change is fueling more intense rainfall at the coast and inland, and with sea level rise, higher storm surge associated with hurricanes and tropical storms,” Graham said.
Peace River reaches record-breaking heights
Below: Use the interactive slider to compare the Peace River before and after Hurricane Ian
The last time the Peace River’s stretch through Arcadia was over 20½ feet, the Titanic had yet to set sail on its maiden voyage.
Enough water to fill 33 billion single-gallon jugs flowed through the Peace River on Oct. 1 — the highest total ever recorded for that area, according to United States Geological Survey data. Seen from space, the width of the winding river balloons as it was overrun with water.
A more than century-old record was broken that day: The Peace River topped out at nearly 24 feet, beating the previous high of 20½ feet set in 1912, according to Chris Anastasiou, the chief scientist of water quality at the Southwest Florida Water Management District. Arcadia communities were inundated with devastating flooding after the storm, impacting thousands of lives.
“What you see in that satellite image is water coming up out of its normal banks and going out into the floodplain,” Anastasiou said. “That was an extraordinary amount of water that had fallen on the ground in a relatively short period of time.”
9 records broken in St. Johns River Basin
Below: Use the interactive slider to compare the St. Johns River before and after Hurricane Ian
It’s a similar story on Florida’s east coast.
At least nine records were broken for high water levels along the St. Johns River Basin after the storm, according to Ashley Evitt, a spokesperson for the St. Johns River Water Management District. Lake Harney, for example, which is located along the river, maxed out at 12 feet, 8 inches.
That breaks an almost 15-year-old record of just over 11 feet, last set in 2008, according to United States Geological Survey data. Satellite imagery shows Lake Harney swelling with water in the first days after the storm.
“Ian was definitely a historic event,” Evitt said. More than 20 inches of rain fell over parts of east-central Florida as the storm swept through the state. To make matters worse, flooding intensified immediately after the storm when a nor’easter pushed south and sent water backward into the watershed.
The consequences of that were still being felt almost a month later. Lake Harney was still in a “major flood” stage on Tuesday, Evitt said. It’s forecast to stay that way at least through the weekend.
“Naturally, it’s a very slow-moving river. So when you have all of this floodwater coming into it, it’s going to take a while for those water levels to recede,” Evitt said. “We saw such extreme flooding: Significant rainfall caused serious and long-lasting floods in many areas of our district.”
Kissimmee River restoration tested by Hurricane Ian
Below: Use the interactive slider to compare the Kissimmee River before and after Hurricane Ian
Hurricane Ian was the first true test for the $806 million Kissimmee River Restoration Project, which was finished last year.
In the 1970s, the U.S. Army Corps of Engineers cut and dredged parts of the river into a 30-foot-deep and 100-foot-wide canal, which destroyed the natural environment and siphoned polluted water faster into Lake Okeechobee to the south. The restoration project corrected that by returning the Kissimmee River into a meandering waterway that could naturally capture and spread out floodwaters.
And what a first test this was: For the northern Kissimmee River area, “We were looking at anywhere from a 200-to-500-year event,” said Sean Cooley, a spokesperson for the South Florida Water Management District. Aerial comparisons from before and after the storm show the newly restored floodplain was inundated, and aquatic plants like cattails were surrounded by seas of freshwater.
“It was very, very, very significant,” Cooley said. Within their 16-county district, there was “very serious flooding” in neighborhoods around central and northern Osceola County, St. Cloud and southeastern Orange County, Cooley said. Water managers were forced to use temporary pumps to move the unprecedented floodwaters.
The Upper Kissimmee Basin saw over 8 inches of rain on Sept. 28. It was the highest one-day average for that area in at least 31 years, according to spokesperson Jason Schultz. Some metropolitan areas, like Orlando, received as much as 15 inches of rain.
Beyond the obvious human impact, the ecological signs of Hurricane Ian’s toll on the restored ecosystem — growing or shrinking fish populations, how wading birds responded, and what vegetation will filter and repair water — will take months to unfold, according to Cooley.
“All of that remains to be seen.”
Below: More interactive before-and-after images of Florida waterbodies in the wake of Hurricane Ian
The Tampa Bay Times worked with Todd Thurlow, a Florida attorney and environmental data hobbyist, to gather before and after images of Florida’s bodies of water. Thurlow acquired short-wave infrared images from the Sentinel-2 satellite program through the European Space Agency to create image comparison sliders on his website. The Times then used an interactive tool, called Juxtapose, from Northwestern University’s Knight Lab to convert sliders to easy-to-use interactives on mobile and desktop. To view more of Thurlow’s data work, visit EyeOnLakeO.com