People are making a lot of good points about boats, but on the other had, I know that indigenous people, poor communities, and communities outside main developed areas use boats a lot just fine! I wonder what the difference is--I was thinking about this earlier. Maybe, in a swamp city (not just water, but kinda salty water, which is even worse), we want to go all in one quick biodegradables--stuff that only lasts for a year or two but then is easily composted. Natural materials, and then digging out the canoes or whatever is a community activity! This wouldn't work for emergency vehicles, because they wouldn't be motored and wouldn't go that fast, but it would prevent big waves from like disrupting houseboats like someone said.

One of the ways that maybe the traditional biomes shown in solarpunk might not translate as well to my city: they really seem to want infrastructure that lasts near-forever, and I literally don't think that's possible here. We're just too storm-battered, too humid, too wet. I'd definitely wanna see what more people think about short-use biodegrades. I know solarpunk hates single-use and waste, but I think maybe this doesn't count if the materials compost well?

I hate cars and car-centric urbanism, so maybe this is a way to make sure the use of boats doesn't just become the way cars are in New Orleans today--a slower pace of life, you have to paddle the boat. More like bikes than cars that way/

These two links have some good pictures on the day to day use of the water busses:

https://thethaiger.com/travel/bangkok-travel/quick-guide-to-navigating-bangkoks-canals-with-riverboats-and-ferries

https://thaiest.com/thailand/bangkok/khlong-boat

And if you search for "Khlong" and Bangkok you can find a lot of pictures from the small canals there. Most famously probably the floating markets, some pictures here:

https://blog.tripcetera.com/floating-market-bangkok/

In fiction, you can pretty much always create a reason, and if you have a reason, then that is valid.

That said, the point of using wetlands as a buffer is that the area is too polluted for long-term human exposure, so you might as well give it to nature. Wetlands do nothing to filter out most pollution, the pollution is either removed through industrial processes or slowly allowed to dissipate out into the ocean. As for how wide wetlands should be - right now that's just the area with an above-acceptable chance of above-acceptable pollution for human habitation or workplace exposure. It depends on where the pollution flows to, how quickly it dissipates and in which ways, etc.

So allowing human habitation in those wetlands is missing the point that caused our capitalist society to restore wetlands there: liberal environmentalists demanded a quota for natural area, and the polluted land is worthless for other uses, so by making them wetlands you satisfy the environmentalists at minimum cost to capital. The animals and plants suffering from the effect of exposure to pollution is not your problem, as long as it still looks pretty enough for photo opportunities and as long as you fund biologists who Monitor the Situation.

Hating to lose things can come from a place of sunk cost fallacy. Reusing existing buildings is often less efficient than building from scratch, and the reason it is so often worth it in the present day is because capitalism is horribly inefficient at land use because land ownership is basically an untaxed way to leech money off the efforts of everyone around it.

However, in your scenario as presented, you're dealing with a neighborhood built by capitalists in the expectation that the neighborhood would be dry land. It seems very unlikely that the capitalists that built it would have paid the extra money to make those buildings able to handle flooding well. This means rotting drywall and insulation, waterlogged concrete, rusting metal frames, essential household infrastructure like fuse boxes and central heating and sewage pumps being destroyed beyond repair in flooded basements, etc. Using these places in spite of that would likely mean either massive maintenance cost or massive health issues.

It is plausible that in a capitalist society a place like this would be used as a shanty town. In most places in the US, shanty towns are demolished by police because "ew, gross" and because they prefer to send the people that would use them to for-profit prisons. However, it would be on-brand for California to officially endorse the shanty town as a capitalist pseudo pro-housing waffle. Between the lack of functioning infrastructure, the toxic pollution, the building damage, and everything else, quality of life would be pretty bad, but many people may choose it over not having a roof over their heads or becoming a slave to the prison industrial complex or even over the quality/cost of available regular lower class housing in California.

In a solarpunk society, I find hard to imagine that living in rotting flooded housing would be preferable to deconstructing the neighborhood and building adequate housing elsewhere. Reuse is only good if the cost of reuse isn't greater than the combined cost of disposal and replacement or salvaging and reuse in a different context.

Maybe it could work if most of the reconstruction efforts were done as a capitalist shanty town. Put one or more decades of capitalism after the flooding, enough that a rich amphibious local culture has arisen, the bulk of the reconstruction costs have already been borne, and pollution has diminished so it's no longer an active health hazard in most of the town. It could be an incrementalist history, where the emphasis on capitalist incentives slowly diminishes over time and people go from living in the shanty town because of work and rent and shelter to living there because of the people and the land, or it could be a revolutionary history, where capitalist structures in the shanty town are finally removed or reclaimed.

With the first option, you would have to be careful to show that this isn't just the first step of the same cycle of gentrification that has affected successful shanty towns since the dawn of time. Many fashionable capitalist consumer things are cleaned-up versions of poor people managing to survive and thrive 50-100 years earlier. What decisions does society make that show it turning away from the cycle of externalization, exploitation, and commodification?

With the second option, you would have to be careful to show which parts are capitalist and which are postcapitalist. When they use something that is only sensible because of initial capitalist investment, how is it clear that they wouldn't build it that way today and what other choices they would make? What makes their lives worse than those of people from flooded towns who immediately got a solarpunk response, and why do they choose this place anyway?

Thank you for your thoughtful response. I appreciate you trying to keep your work accessible and comprehensible to casual viewers, and that it's hard to describe a happy relocation, especially in a single image. You've clearly put a lot of thought into the messaging. I personally have difficulty accepting flawed/imperfect/good-enough solutions, and it's nice to have more grounded people actually getting a positive message out there even at the cost of accuracy.

All of that said, refugees and migrants already exist, and they already face the same struggle of wanting to preserve the culture they have been forced away from. The question of how to make migrations as pleasant as possible and rebuild as much of the physically embodied culture that was left behind as possible is one that is very relevant right now, so I would love to see you make a postcard of a migrant town, if you don't already have one. If you can show how even migration can be a place of solarpunk joy, then suddenly the people of New Orleans do have a realistic joyful future despite the bleak prospect of evacuation.

Personally, a full diaspora seems like an unnecessary loss. Modern western policies of spreading migrants thinly over as wide an area as possible to prevent them from coming together to celebrate the world they left behind are horrific. Migration is at its most beautiful in a place like 19th-20th century New York City, with the best parts of several dozen distinct cultures being reproduced side by side and then mixing together into something novel and rich.

If New Orleans had to be evacuated, I wouldn't want its culture to dilute as everyone from there is forced to make the separate choice to let their distinctiveness be subsumed by their peers. I would like a bunch of Little New Orleanses, hundreds of migrants all living together in the same neighborhood celebrating the old culture and mingling with the locals, choosing their own rate of change and having enough mass to make other groups consider their perspective and values and artforms.