Sea level rise is considered a distant problem by millions today; either distant in years, distant in miles, or both, but they are greatly mistaken. I’ve just finished the book The Water Will Come, much of which is set in Miami Beach, where I live. For Wanda and I, the problem is here, and now. I remember the king tides in the fall of 2013, when I recorded South Beach at Sea Level, and I’ve worked with local leaders on ways we might adapt. And the decisions we make as a city today will determine whether we survive in the future, including decisions that allow us to preserve the character of this place that attracts people today from around the world.

Not every coastal town will survive. Actually, most will not. And the terms of retreat will have a great influence on whether the impact across America is orderly, or whether we descend into chaos, or whether it’s something in between. But make no mistake: when thousands, then soon millions of people begin to retreat from the places that cannot be saved, that great migration will affect all parts of this country, not just the coastlines.

I was a participant at the CNU Climate Summit in Alexandria last fall, and drew up a proposal for the real estate end game which is laid out below. The key point is that not every place is the same, and so what those places do to adapt will vary greatly.


Miami Beach’s iconic Ocean Drive

Elevate & Harden

Some places have enough money to adapt in place by raising and hardening. Miami Beach is likely to be one of them. I’ve been involved in the conversation there as noted above, so this is a report from the front lines, not just a guess.

Choice Criteria

The degree of sea level rise is uncertain, of course. City leaders in Miami Beach have aggregated sea level rise projections and are now adapting for their best guess of what would still work a century from now. The choice is a local choice, made by the city and not by larger entities.

Measures

Miami Beach is raising streets; the lowest streets that have had the worst sunny-day flooding are being raised as much as 42”. The elevation tapers to zero near the middle of the island where the natural grade is this much higher. Water and sewer lines are being raised and upgraded on streets that are rising, and the new storm sewers drain to huge underground detention tanks on the West side of the island, from which water is pumped out into the bay. Unfortunately, this leaves the buildings in a hole. Buildings are already flooding as storm drains inevitably clog. To date, the city has been able to plead with insurance to pay for the flooding, making the case that it was a rare event cause by an incomplete tank-and-pump system. It is not. Buildings inevitably will have to elevate. Short buildings can elevate easily; tall buildings can give up their second level and move their ground floor up a level. There may be a “sour spot” of maybe 4 or 5 to 12, 13, 14, or 15 stories where the buildings are too tall to elevate but for which it is not economically feasible to give up a floor. These at-risk buildings are often some of the iconic Art Deco buildings which are a huge source of tourism, and some local architects are salivating at the chance to destroy them and replace them with their own ego towers. If the architects succeed and do not respect the character of what they are replacing, it could be economically crippling to the city to go from being a world-class center of Art Deco to just another beach town with a random collection of architectural styles du jour.

Financing

We have no illusions that anyone is going to bail us out. Fortunately, the math is pretty simple, because insurance premiums decrease the higher buildings are elevated above BFE. With insurance rate trends now, the payback on elevation is probably a decade or less. The absolutely critical key is to get the insurance companies to lay out what the premiums will be at various levels of elevation so that people can make informed decisions. Without this, the entire process will fail.

Tools

Because there is financial incentive for elevating higher, pattern books are needed to deal with the private frontage conditions created by elevation. In all likelihood, buildings will elevate higher than streets, creating different conditions than exist today.

Precedent

Galveston elevated both streets and buildings to above the 17’ elevation of the new seawall after the hurricane that remains the deadliest in US history. Many buildings were wood frame, but some were masonry as well, including a large church building. Chicago elevated many blocks of urbanism near the river in the late 19th century because of flooding and disease. They raised both streets and buildings, creating “Underground Chicago,” which is largely used for parking today. Most often, they were elevated a block at a time to avoid the problem of party wall buildings. They were elevated with screw jacks operated by human labor to the beat of a drum to keep the progress equal all down the block. They usually did so without cracking a window pane anywhere in the block, and one landmark hotel was elevated while still being occupied by guests every night! Underground Atlanta did not elevate the buildings, but began by building a series of bridges at the second level which were later connected to form continuous streets. Shopfronts were moved to the new street level and the old street level space was first used for storage, then became an entertainment district complete with speakeasies during prohibition. It remains an entertainment district today, but is currently closed for renovations. Bay Village is a small Boston neighborhood at the southeast corner of Back Bay that began flooding badly when Back Bay was filled, as much of the Back Bay runoff flowed across Bay Village. Almost all of Bay Village is masonry bearing wall construction from the early 19th century and earlier. It was elevated 23'-26’ using manually-operated screw jacks in the mid-19th century, much like Chicago a few years later.


Detroit, given up for dead for decades, could be a classic receiving city.

Individual to Receiving City via Insurance

This may be the most commonly-used method. It will be the most gradual and orderly method, and will likely happen over a number of years in most places. At best, this method compensates homeowners a maximum of $250,000 by flood insurance plus whatever price they can get for their flooded home.

Choice Criteria

In the wake of repeated insurance rate hikes in places not wealthy enough to elevate & harden, individuals will realize that it’s simply too expensive for them to live in this place any longer, and will choose to move elsewhere. This will work best in the early years, when there are still buyers for the real estate being vacated, albeit at reduced rates. Later, when there are no more buyers for anything higher than just the land value, this may become more chaotic, especially once cities can no longer afford to service the flooding areas.

Measures

In order to walk away from their home, there needs to be a broadly-understood narrative that compares their cost of ownership all those years with the cost of renting. If someone can say “I would have spent more renting than what I spent owning,” then it makes it easier to walk away.

Financing

Even if they wait long enough that their property is widely recognized as being uninhabitable, there will likely be some uses for the land that gives it some value, so they may be able to sell it for something like a rice farm, which is expected to be flooded part of the year. The more likely transaction is to a developer looking to aggregate properties to the point they can elevate and harden the property for some use, whether resort or industrial. In short, they may be able to sell out at a steep loss, but leave with some cash in their pockets beyond the insurance proceeds.

Tools

There will likely be sites and apps aggregating cities looking to attract sea level rise refugees, and laying out their proposals. “Our deal is better than Detroit’s deal, and here’s why.” At the very least, the move itself should be covered. One aspect of the sites and apps is that they should tag trades and skills the places are looking for, so a grocer or a metalworker could decide where they’re most needed. Another essential tool will be the single-crew workplace, as the refugees are unlikely to be able to set up their new operations at the scale of their old. Single-crew workplaces can operate from tiny quarters such as food carts and retail shacks such as Perspicasity at Seaside, where those humble plywood boxes are so beloved that the Town Founders have been unable until now to remove them and replace them with something more substantial. Without single-crew workplaces, many refugees would not be able to set up in business again. Receiving cities must therefore have codes which allow single-crew workplaces in temporary quarters, at least in Receiving Zones. Many Katrina Cottage principles will be in play here, allowing people to regain a foothold in their new home with a tiny footprint which they can expand later.

Precedent

Seaside, Florida is the birthplace of the New Urbanism and also the best precedent in our time for a broad spectrum of temporary structures. Single-crew workplaces exist all across the developing world, especially along the Caribbean Rim.


Serious protests will likely lead to worse things in relocation by government order.

Individual to Receiving City via Government Order

This may be a common method as well, but will be more disruptive than the methods above. See New Orleans ex-mayor Ray Nagin’s proposal to abandon the Lower 9th Ward, and the firestorm that ensued, prompting him to withdraw it 24 hours later. Telling people they cannot come back home is one of the most difficult things a politician will ever attempt.

Choice Criteria

This is a mandate by the city, the state, or the federal government. The individual property owner has no choice under this model.

Measures

The first measure is likely martial law, without which there could be a revolution, depending on how broadly the evacuations are ordered. If several cities in one region are evacuated, a revolution is likely; if statewide or broader, count on it. Beyond that, there must be a strong story-telling initiative of the renting-vs.-owning narrative described above.

Financing

The ordering entity must bring truckloads of cash, or the revolution may proceed anyway, even if it’s only ordered in a city or two. Of all methods, this will be the most expensive, and will likely get tied up in the courts for years as countless homeowners sue the government.

Tools

First, bring force because this method could get out of hand and quickly turn ugly. Beyond that, the government issuing the order needs to be actively promoting the story-telling and the relocation apps, and should probably be prepared to help the receiving cities with mobile structures for dwellings and single-crew workplaces in their new hometowns. The ordering entity should also be prepared to provide refugees with food for their journeys and some colder-weather clothing for the long term, as most migration will be northward.

Precedent

Antigua Guatemala (the old Guatemala City) was hit with an earthquake, a volcanic eruption, and a flood within about 15 minutes in 1773. The earthquake/eruption shattered the volcano's crater, which held a lake, hence the flood. The government deemed the city cursed and ordered everyone to leave for the current Guatemala City, under penalty of death. Some did not comply, of course, and hid in the ruins for decades, subsisting on avocados, hence their nickname “panza verde,” or “green bellies.” This will happen in our day as well.


Tight-knit, low-lying, low-budget community

Neighborhood to Receiving City via Insurance

Some neighborhoods, because of their family and civic bonds, may elect to move together to a receiving city when their homes become uninsurable.

Choice Criteria

Neighborhood and family elders will make the decision to leave on economic issues centered on insurance price hikes.

Measures

This will be one of the most orderly evacuations and require the fewest imposed measures, because the decision to leave will have been made by the elders. The renting-vs.-owning storytelling will be a strong measure, imposed by the most trusted members of the neighborhood.

Financing

The financial model will be similar to that of Individual to Receiving City via Insurance: a combination of insurance proceeds and real estate sales at much-reduced prices. And to make matters better, community elders are likely to negotiate better deals with the receiving city than any individual could.

Tools

The tools should be largely the same as Individual to Receiving City via Insurance, with the immediately preceding caveat about the better negotiated deal.

Precedent

I don’t know of an entirely parallel precedent, but study the migration of entire rural communities from Kentucky to Ohio in the 1950s seeking work. My mother’s family was from rural eastern Kentucky and the entire immediate family moved to suburbs of Cleveland in this era (but without the help of insurance).

Neighborhood to Receiving City via Government Order

This will be like Individual to Receiving City via Government Order, but much more orderly because the government entity will negotiate the departure with community elders, who will then persuade the community as a whole. Also, because the neighborhood will be moving largely intact, it will seem less disrupted in its new home than individuals would be moving alone. The downside is that because they are moving as a large group, that is likely to be disruptive to their new hometown unless it is a place like Detroit with large abandoned areas.


DPZ CoDesign Bento Cabins

Individual to New Town via Insurance or Government Order

This method will invoke the most New Urbanist tools and techniques, and this may be more common than is generally assumed today. The standard narrative is that governments at all levels will be financially stressed by sea level rise refugees and will be less likely to fund the construction of new towns, but new towns in the US have only rarely been built by government anyway. They have almost always been built in this country by private town founders.

There is a very different dynamic in play with new towns versus receiving cities. A receiving city is one which has experienced failure of some sort in the past, and therefore has underinhabited areas available to receive sea level rise refugees. Detroit is the iconic receiving city. A new town, on the other hand, is emblematic of a fresh start. Some people are more drawn to places with long histories and established culture; others are drawn to places fresh and new, but with most of their cultural assets not yet built.

For most of American history, the inaugural condition of a new town was dirt streets lined with tents, until the people could build log cabins, sod huts, or some other humble dwelling to seriously get started with their new life. Fortunately, we’ve moved a bit beyond those early American starting point, and some really smart people are working on some cool alternatives. DPZ was one of the founders of the New Urbanism, and Andrés Duany and friends at DPZ have been spending most of the last couple years designing a series of mobile dwellings such as the Bento Cabins shown above which can easily be used to found a new town or to reinhabit parts of a receiving city.

Choice Criteria

An individual or family could choose to move to a new town over a receiving city for reasons as varied as they are. The only commonality I anticipate is that the appeal of a fresh start in a new place could make the move easier emotionally to those moving, so they may be less predisposed to be part of the uprising that will take place in many places evacuated by government order. The better the founding stories of the new towns, the easier the move may be. Governments ordering evacuations should take note, and do everything they can to help the new towns succeed. As a matter of fact, the success of the new towns may play as large a role as any in limiting violence due to sea level rise.

Measures

The strongest story-telling measures will come from the destination town, not the departure town. As with other migrations, the renting-versus-owning departure narrative must be strong, but that should be outweighed by the story of the new town, which can and should be powerful, in large part because the new place hasn’t screwed up anything yet.

Financing

Because this process works best with more financially solvent refugees, new arrivals are more likely to have significant assets than those of other migrations. This bodes well for the relative success of the new towns.

Tools

The apps and sites mentioned above will be helpful, but due to the scale of the new towns versus the much larger receiving cities, the appeals to certain trades, skills, and businesses can be more precise. “We need a grocer” is more impactful than “we need a few more grocers,” and more likely to get a grocer to move there.

Precedent

This is what happened in almost every US frontier town of the 19th Century. We’ve done this before; we can do it again. That was the westward expansion; this is the inward expansion.


New town shops and dwellings that don’t start as mobile structures should still start small so as to not burden the financially stressed people moving there from their old town.

Old Town to New Town

This method is rare, and requires the most work, as the governance of the new town must be set up in advance in the new place by the leaders of the old town, who must have agency in the new place.

Choice Criteria

The choice to move from an old oceanfront town to a new inland town is a decision made by the city leaders, who then persuade their citizens (or at least the great majority of them) to make the move with them.

Measures

The story-telling here must be heroic in order to succeed. Enticing individuals from coastal places all over to a new town is easy compared to the much taller task of persuading the great majority of the residents of a particular place to move to a new town somewhere else. But the benefits of maintaining cultural connections and supportive friendships is great, so this method should be encouraged.

Financing

Because the town moves largely intact, the business owners and employees largely retain their original roles in the new place.

Tools

Fewer of the tools above are needed here, because there is less disruption of connections. The grocer here will be the grocer there, for example. The big difference will be the fact that pretty much everyone will be impoverished by the move, and so lean urbanism tools like single-crew workplaces will be important to allow people to restart their lives, but at a smaller scale.

Precedent

I haven’t found confirmation yet, but I believe that Anderson, Indiana was founded by people from a Tennessee town which picked up en masse and migrated there.