When tides reach their highest in Miami Beach, they don't just wash up on beaches anymore. Due to rising sea levels, high tides now bubble up through the sewers, flooding the streets with inches of saltwater.

Despite the encroaching waters, the city is currently building some of the most expensive beach-front real estate in its history in an attempt to bring in tax dollars to fund protection of those same beaches.

_The Washington Post _outlined the extent of Miami's real estate boom: 12 condos under construction going for an average $1.1 million, a Canadian investor planning to develop a $23 million stretch of North Beach, and a new $55 million beachfront condo — the most expensive in the city's history.

"If the state of Florida is in a short-term bind to get its budget fixed, good luck to them if they want to do that with long-term liabilities," Klaus Jacob, a climate scientist at Columbia University's Lamont-Doherty Earth Observatory, told VICE News. "It reminds me of essentially the buildup to the financial crisis, where everybody goes to the short-term benefit and sooner or later the whole system collapses. That's what Miami will have to face up to."

As global sea levels rise, coastal communities around the world are facing issues unique to their locations, ecologies, and infrastructures. In Florida, where population has grown from less than a million people to more than 19 million in 100 years, residents and planners must deal with encroaching waters, intense storms, and degraded naturally protective marshes using mid-century water systems that were built without rising sea levels in mind.

"The condos look nice, but it's unbelievable that they're building it right there in Miami Beach," Peter Sheng, a coastal engineer at the University of Florida, told VICE News.

The development has already proved a financial boon for Miami, which the Post reports has seen a $14 million increase in property taxes since 2012. Some of that tax money will go toward funding 80 new storm pumps, which function better than gravity-based drains under frequent flooding from rising sea levels.

But Miami's problem is more complicated than simply pumping out water when it floods. The southeast tip of Florida sits on top of the Biscayne aquifer, a 4,000 square-mile layer of porous limestone from which many residents get fresh water. As rising seas encroach upon southern Florida, that porous nature means salt water can get into wells and sewer systems from underground, contaminating the freshwater supply and overflowing into the streets.

"The concern is that these wells will have to be abandoned," Jayantha Obeysekera, chief modeler with the South Florida Water Management District, told VICE News. "We can stop water above ground. We can't stop water underground."

Some of the coastal well fields are already flooding, Obeysekera said, with modeling indicating that the problem will move inland within the next decade or two. South Florida is already seeing street flooding associated with king tides — the highest tides of the year — though the two pumps Miami Beach has installed alleviated the problem this year.

"On the one hand, the city mayor seems to be very progressive, very proactive," Sheng told VICE News. "They're building pumps, fighting this King Tide. But on the other hand they're building like crazy. I don't think it's a wise thing to do."

King tides are the highest tides of the year, occurring when the alignment of the Earth, moon, and sun create the strongest tidal forces. They happen once or twice each year, depending on location.

Miami and other coastal cities should instead build themselves "amphibian powers," Jacob said, raising roads and building submersible properties and infrastructure — if they don't abandon the coasts altogether, a generally unpopular suggestion outside of the science community. But predicting just how much — and how fast — sea levels will rise in the coming decades, and centuries, is still full of uncertainty, making it to difficult to know just how to invest and protect, Obeysekera said. Some properties in Key West are doing just what Jacob recommends, building properties with first floors that can handle flooding.

"Our best strategy is to come up with a strategy for the next couple of decades and watch where the data is going," Obeysekera told VICE News. "The development has already happened. So now the question is how do we change and make sure that people who want to invest in this region have some comfort level."

"It just doesn't make sense to invest into Florida, that's the short end of the story," Jacob told VICE News. "But of course nobody wants to hear that."

Follow Laura Dattaro on Twitter: @ldattaro