We got through Irma. And now the king tides are coming.

On the heels of Hurricane Irma and just as Hurricane Maria began battering already ravaged islands in the Caribbean, South Florida is getting another meteorological reminder of the region’s vulnerability to rising tides.

Just a week after Irma littered streets, knocked out power and damaged properties, the initial round of this fall’s king tides rose this week. The debris from Irma challenged cleanup crews who had to pick up large loads of refuse and unclog storm drains to deal with the tides’ higher water, while scientists observed the flooding and gathered data.

These seasonal high tides are known for swamping docks and flooding streets. They rose twice a day on Monday, Tuesday and Wednesday, creating the first round of sunny-day flooding this fall. King tides rise each year in September, October and November when the sun and moon align to create a stronger gravitational pull on the ocean. October’s tides are typically the highest of the year.

That extra tug causes flooding in low-lying coastal areas across South Florida, which sits on a layer of porous limestone that saltwater can intrude into through drainage systems.

As the tides flooded low-lying streets in coastal Miami, researchers and volunteers waded in brackish water to collect data about the chemical makeup of the floodwater. Flooded streets made residents in Fort Lauderdale uneasy while they awaited electricity and dealt with property damage from Irma. Public works crews in Miami Beach cleared streets and storm drains of storm debris, limiting the capacity of the city’s drainage system.

“The cleanup efforts are somewhat complicating the king tide preparation,” said Eric Carpenter, the Beach’s public works director. “The debris in the street and in our drainage systems is limiting some of our capacity for a period while cleanup is performed. We are cleaning our drainage systems concurrently with cleaning our streets of debris.”

Across Biscayne Bay in the Upper Eastside of Miami, a consortium of public health advocates, volunteers and researchers from Florida International University waded in shin-deep water Wednesday to gather data to develop a “community health map” that would create a picture of the area’s health risks as they relate to king tides and, by coincidence, the aftermath of Irma.

They took water samples and tested the chemical makeup, interviewed residents about their damage and trained local community members how to keep gathering data in the future. It’s part of an effort to make property owners and renters aware of their environment and the health risks posed by events like king tide.

The testing reveals how much salt is in the floodwater, which will help FIU scientists understand how water in the storm water system mixes with saltwater from the adjacent Little River.

“This is more about the community being able to be engaged,” said John Scott, of the Center for Public Service Communications. His organization is partnering on the project, which is backed by the National Library of Medicine, an arm of the federally run National Institutes of Health, and will be sharing data with the city of Miami.

Part of the work will examine equity in infrastructure improvements, particularly in the face of rising sea levels fueled by climate change. Whereas certain neighborhoods may have the financial means and political connections to push for better drainage of their streets, others just around the corner may not.

“These folks need this fixed,” said Nancy Metayer, a climate justice organizer from the New Florida Majority, as she pointed toward two apartment buildings that had Northeast 10th Avenue flooded right in front of their buildings. “It’s not fair.”

Amid the cleanup in Fort Lauderdale on Tuesday morning, water started to spill over the seawall in Las Olas Isles and Lauderdale Harbours. Homeowner Steve Paskoski stood in a puddle of water on the sidewalk in front of his home as he explained drainage problems to city engineers.

Next to him, a large heap of splintered tree branches covered most of the swale, looming over the grated storm drain where water was bubbling up.

He also said that over the 25 years he’s lived there, the king tides have gradually crept farther up his driveway, particularly in recent years.

“The last couple of years it’s been much worse,” he said.