Miami and Miami Beach already struggle with serious flooding related to sea-level rise — even when there is no rain.

The ground under the cities of South Florida is largely porous limestone, which means water will eventually rise up through it.

The cities are taking flood-control measures like installing pumps, raising roads, and restoring wetlands.

Coastal cities around the world face similar problems.

When the flooding is really bad, water doesn’t just fill the streets outside Manolo Pedraza’s house. It bubbles up through a shower drain.

Pedraza lives in Shorecrest, a northern Miami neighborhood that faces flooding so regularly it happens even when it hasn’t rained. All it takes to fill the streets to knee-high depth on those days is a full moon. The flood comes up through storm drains, making it impossible to navigate without encountering the water, which is mixed with sewage and whatever else it picked up along the way.

During a visit to Pedraza’s neighborhood, I walk only where the water, likely filled with fecal bacteria, won’t rise above my waterproof boots. I’m lucky that day. Pools cover parts of the streets, but at least I can walk the area without soaking my feet.

“This is nothing,” Pedraza said in Spanish. “Sometimes it comes all the way up to the house.”

Sometimes, floodwater bubbles up through the shower drains in the house where Manolo Pedraza lives with his family. He built up their driveway after flooding damaged two cars. (Photo: Kevin Loria) Sometimes, floodwater bubbles up through the shower drains in the house where Manolo Pedraza lives with his family. He built up their driveway after flooding damaged two cars. (Photo: Kevin Loria)

The “sunny day flooding,” as it’s known, is consistent enough that you can look at a calendar and a tide chart to plan a trip around it. High tides, caused by interactions between the sun, moon, Earth, and oceans, are behind the flooding. I visited during what are often the highest tides of the year, known as king tides.

Miami “is kind of the poster child for a major city in big trouble,” said Jeff Goodell, author of " The Water Will Come: Rising Seas, Sinking Cities, and the Remaking of the Civilized World."

Beyond the damage to homes, roads, or other infrastructure, the flooding also threatens drinking water and plant life. Ultimately, of course, it means large parts of the city could become permanently uninhabitable.

That means the rest of the US should be paying close attention to how Miami handles its struggle against sea-level rise in the coming years. It could provide a window into the future for other large coastal urban areas.

The Netherlands has been holding back the oceans for decades and is exporting its knowledge to cities such as New Orleans. But the Dutch have been building on land reclaimed from the sea. In Miami it's a different situation.

When low-lying neighborhoods in Miami and nearby Miami Beach were built up decades ago, they weren’t developed with the assumption that seas would rise over time. In some places, buildings and roads are being raised or moved; in others, natural features like mangroves, reefs, and wetlands are being restored.

Those are the kinds of changes that might be enough to keep much of Miami above water for at least a few decades. Planning longer term is trickier.