For a tiny village, a big problem. How does a chain of man-made islands survive sea rise?

North Bay Village, an island community literally scraped from the bottom of Biscayne Bay, now has a problem with waters that surround it.

Sea levels are rising, threatening the small but prosperous man-made islands. In response, North Bay Village is devising a plan to keep its 9,100 residents dry until the end of the century.

“We’ve risen out of the bay one time in our history. There’s no reason we can’t rise above the water again,” said Mayor Brent Latham.

The stakes for the tiny village — it occupies less than a square mile of dry land — are high.

According to an analysis by Climate Central, the village has $74 million in property value at risk of inundation under two feet of sea rise, which is expected by 2060. At six feet, the predicted rise by century’s end, nearly the entire village would be underwater.

South Florida Regional Planning Council

The answer is elevation. Every restaurant, condo, house and road eventually needs to come up, and so do the sea walls flanking the islands.

North Bay Village has acknowledged as much, but the village plans to go about it differently than most South Florida communities: private first, public second.

Unlike its neighbors, Miami or Miami Beach, which have large swaths of waterfront parks they can armor against the encroaching tides, North Bay Village has to encourage the private market to do most of the adapting. Except for two small parks, nearly every inch of the village’s waterfront is privately owned. The idea is to have them go first, encouraged by incentives baked into a revamped master plan.

“You have to let the market work its magic,” Latham said.

It’s not that the public infrastructure isn’t at risk. It is.

King tides routinely swamp roads and lawns in the island village, largely in the single-family home neighborhoods. South Treasure Drive can see up to a foot of standing water when flooding gets really bad. The village is upgrading its old and leaky storm and wastewater system. The broken pipes wash out fill under the roads, causing the streets to deteriorate faster.

The mayor acknowledges roads will have to be raised, eventually, but said by elevating buildings first, “we’re not causing issues where the streets are higher than the community.” He’s referencing Miami Beach’s highly publicized road raising efforts, which has been complimented internationally but drawn sharp criticism locally.

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The village’s idea to have private development adapt first will be set in motion by a new master plan, which is being developed by Miami-based urban design firm DPZ CoDesign along with an “action plan” of signature projects for the village.

The projects range from short-term (an alley turned into a public space with food trucks) to mid-term (building a new village hall) to long-term (a boardwalk connecting the north waterfront side of Treasure Island). One idea involves creating an elevated public square in the center of town with restaurants and seating.

“It will be a symbolic way of beginning to think about sea level rise and to begin thinking about elevating public and private areas,” DPZ Managing Partner Galina Tachieva told commissioners and residents at a meeting last week.

DPZ will present the master plan to the commission in the spring, along with final versions of the signature projects. In the meantime, designers will come up with incentives that convince people it’s worth it to elevate their homes and businesses to at least the current height required for new construction in the area — nine feet above sea level.

Every single property has to be raised about five feet to come to new codes,” Tachieva said, and updates to FEMA flood maps due next year could push that base flood elevation (or BFE) even higher. Homes and buildings below the mandated height pay much more for insurance, or sometimes can’t access it at all.

“At some point when the new BFE comes into place, they have to be insured somehow and if they stay where they are today, they won’t be insurable,” she said.

This alone could push homeowners into raising their houses, and Tachieva’s team hopes to sweeten the pot by possibly allowing more density or small observation towers (like the ones seen on some of Florida’s barrier islands) for homes that elevate.

One way to encourage North Bay Village single-family owners to elevate their homes: small observation towers. DPZ CoDESIGN

Elevating, however, is an expensive endeavor. Raising a single-family home can cost in the neighborhood of $200,000, and elevating can trigger village rules that force a property to fully adapt to the newest codes.

But perhaps the most important subject to tackle in North Bay Village is sea walls. The village is literally held together by the bulkheads filled with dredged dirt from the bottom of Biscayne Bay in the 1940s.

“We heard that from North Bay Village, the sea walls were more about how to keep the land in. Now we have to think about how to keep the water out,” Tachieva said.

There’s just one problem for the village: Nearly every inch of the four miles of sea wall that encircle the islands is privately owned. Right now, it’s up to homeowners and businesses to protect the island from the double danger of storm surge and rising seas.

Ask Jack Rattner, a 52-year-old business tech advisor who’s lived in the same home on North Bay Island his whole life. His house, like most waterfront homes in the village, still has the original sea wall. Only now the aging infrastructure bows out in places, literally ripping his patio away from his home.

“They’re just S’s,” he said. “Every sea wall in North Bay Village that hasn’t been replaced is in imminent failure.”

And when king tides, the above-average seasonal high tides, come to town, the water laps at the edge of his sea wall in a way it never did when he was a kid. The slightest breeze sends saltwater into his yard.

Rattner knows he needs a new sea wall. And he even wants to build the new one higher. But at nearly $1,500 a linear foot and with more than 80 feet of sea wall to replace, it’s a cost he can’t afford right now.

That’s when Mayor Latham’s plan comes in. The mayor wants the new codes to reflect a scientifically selected proper height and building technique (standards chosen perhaps in conjunction with the University of Miami) for a state-of-the-art sea wall that rings the whole village.

Once the codes are officially in place, Latham wants to approach single-family homeowners with an offer — either build your new sea wall to the new code at your own expense or let the village build it for everyone at once and tax waterfront homeowners to pay for it.

There would be a few years between the announcement and the actual project start date, he said. That gives the village time to find grants to help bring down the cost. Plus, “the sea level is coming up in the meantime. You’re going to get more and more converts over that timeline.”

“This should be economically compelling to individual homeowners and provides what the village needs, which is a continuous state of the art sea wall,” Latham said.

A recently built section of sea wall along the waterfront at Harbor Island in North Bay Village on Oct. 10, 2019. Jose A. Iglesias jiglesias@elnuevoherald.com

For commercial areas, which are already required to include a public boardwalk in new codes, the village plans to use some grants it already has to design and permit the interconnected “island walk” and brand new sea walls. Latham said North Bay Village is looking for more grants to subsidize the public-private partnership further.

A new coat of armor against the ocean, as well as codes that point toward a more resilient future, would do wonders for North Bay Village’s real estate market, which Latham said is suffering from some anxiety over the impact of climate change. Multiple studies have shown home buyers are beginning to prefer higher elevation properties in Miami-Dade County and property values are growing slower in lower elevation areas like North Bay Village.

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“When you look at our village, generally speaking, there’s a trepidation in the market,” he said. “If we can create a climate where we can convincingly say a real estate investment is safe for the coming decade, that’s going to add value when it comes to property values and investment.”

The idea of leaving the little islands in the bay never came up at the community roundtables, Tachieva said. Residents were more interested in learning how to fortify their community against the invading seas.

“I don’t have an escape plan,” said Rattner. “I don’t want to leave. I want to be a part of the solution. I want my son to grow up in the family home.”

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Alex Harris covers climate change for the Miami Herald, including how South Florida communities are adapting to the warming world. She attended the University of Florida.