A note from Team Epic Reads: This post comes to us from Dan Wells, author of Partials and Fragments – both on sale now! He is also part of our Dark Days Winter Tour.

Will Your Hometown Survive the Apocalypse?

One of the most awesome things about writing a book like PARTIALS is that it gave me the chance to imagine our world after an apocalypse destroys it. When Kira makes her journey into Manhattan, it’s both instantly recognizable and completely alien: there’s the familiar skyline, but it’s covered with vines and ivy; there’s the Brooklyn Bridge, but it’s covered with junked cars and wired with explosives. At one point, Kira is being chased by enemy soldiers and thinks about hiding in the subway system, only to realize that it’s completely filled with water. This little moment is in the book because I, as the author, also thought it would be cool to have a chase scene in an empty subway tunnel, only to do the research and realize that Manhattan’s subway system is well below its own water table—massive pumping stations are draining water out of the tunnels almost constantly, and even a small disruption can flood the whole thing. Hurricane Sandy flooded the subway last year, giving us a pretty famous glimpse of what it looks like when it happens, but even normal rainstorms can have a similar effect. Human beings are fighting a constant battle against the elements, and as soon as we stop doing that—if, for example, 99.997% of us die in a horrible plague—the elements will reclaim our cities.

So: what’s going to happen to YOUR city after the apocalypse?

Let’s start with some of the big, obvious stuff first. Any city on a coast is going to be smaller, simply because the shores are being constantly washed away, and the ocean levels are rising. Long Island, where most of PARTIALS takes place, spends hundreds of thousands of dollars every year dumping tons of new sand on its beaches to replace the stuff the ocean takes away; once humans disappear, we won’t be able to do that anymore, and the coasts will erode at a surprising rate (according to a study from 2011, that rate is about 1.6 feet per year, spiking as high as 60 feet per year in extreme cases). So basically, the Long Island Kira knows is a very different place than the one you’re familiar with.

Another coastline in danger is North Carolina, where the outer banks are covered with homes and buildings and resorts and every kind of development you can imagine, most of it exactly at sea level. If the sea level rises even a few inches, that entire area will flood—which is nothing we can’t handle, honestly, because humans are amazing. Look at Dutch cities like Rotterdam, much of which exists below sea level, and you’ll see the kind of ingenious engineering we can use to keep the ocean at bay—levees, sea walls, and more. The trouble with those systems is that they need constant maintenance, though, so once humans disappear, so does Rotterdam, and so do the outer banks in North Carolina, and so does a massive chunk of Florida, and so does pretty much any coastal city. Remember what Hurricane Katrina did to New Orleans, breaking the levees and flooding the city? If you live on a coast, your city might look like that too.

You know what else is going to flood? Chicago. If you live in Chicago, take a look at your canal system: it is a miracle of modern science, literally the most heavily engineered water system in the world. Chicago controls its water so precisely that they have actually reversed the flow of the Chicago river, sending clean water out of Lake Michigan instead of dumping dirty water into it. Much of the terrain in and around Chicago is low, and used to be marshy, but the water system has fixed that, too. And once again, in what’s becoming the theme of this post, that water system requires constant human maintenance to work properly. When we go, the engineered flow of artificial rivers goes with us, and one of the biggest cities in the world will return to its mushy, swampy origins. Spend any time in post-apocalyptic Chicago and you’re going to get very, very wet. Just ask Kira.

Water’s going to be a problem in several other cities, but instead of having too much they’ll have way too little. Las Vegas is in a state of constant water crisis, even today, spending millions of dollars a year struggling to keep from dehydrating; they restrict their water so heavily that even having a lawn carries heavy extra taxes, even if you don’t water it. When humans disappear and the pumps shut down, Vegas will dry up like a mummy in a matter of days. This is what happens when we build a giant city in the middle of a desert that can’t possibly hope to sustain it. A lot of our desert cities are in a similar boat. Palm Springs sounds nice, but without humans to carefully terraform it, that city is a desert wasteland. Los Angeles and San Francisco will fare a little better—we’re filling them with more water than nature ever wants to give them, but they have a few water sources of their own. Of course, they are on the coast, so major changes in sea level will flood them, and they’re on some famously touchy fault lines, so any earthquakes will shake them to pieces—and without humans to put them back together like we usually do, they’re only going to get more and more broken and flooded as time goes on.

Most of my examples so far have focused on water in one way or other, simply because it’s the single most powerful force on the surface of the planet. There are things below the surface, however, that we’ve brought up in massive quantities, and when you get them all together they have the potential to affect our post-apocalyptic world in a drastic and terrifying way. The city of Houston is the largest oil refinery system in the world, bar none; we store and process so much oil in Houston, we even do it for countries that produce their own oil—they bring it here, we refine it into gas, and they take it back. The oil refining complexes in Houston cover more physical area than a lot of major cities, and, as always, that kind of system requires constant human supervision. Let’s assume that human workers manage to turn off all of that machinery before they die of the plague, and that the copious safety measures manage to stop anything terrible from happening—how long are those safety measures going to last? The electrical ones will fail as soon as the power grid goes down. The others will last only as long as their physical components survive: metal pipes, rubber O-rings, weak points like joints and valves and seals. An earthquake or a flood will accelerate the decay, and while Houston isn’t exactly on a coast, it might as well be. Sooner or later something will fail, and all it takes is a brush fire or a lightning storm or a really hot day, and Houston will burn for decades. Entire generations of post-apocalyptic refugees could be born and live and die seeing Houston as nothing more than an eternal fire. And what happens when toxic chemicals create toxic smoke for years on end? Well, that smoke has to go somewhere, and. . .well, I’ll leave you to discover the rest when Kira does. It’s not pretty.

Obviously I can’t cover every city in the world, but you can look at your hometown and figure out a lot of this for yourself. The first thing to consider, of course, is nature: Is your city constantly fighting against the elements, trying to deal with too much water or not enough? Is your city stubbornly trying to survive in an area plagued by earthquakes or erosion or hurricanes or some other force of nature? Venice struggles daily not to be swallowed by the sea. Mexico City and Puebla are each built around a volcano. And if you’re downstream from a dam—or upstream, for that matter—well, I’m sure you can think of some plausible scenarios for how that’s going to end. Human civilization exists because humans are amazing, and we fight back against the forces of entropy because we don’t know when to quit. But if RM or some other disease ever makes that decision for us, nature’s coming back with a vengeance, and the city you live in could become a very different place almost overnight.