The idea of alligators lurking in city sewers has been a long-standing urban legend. From New York’s subway myths to Florida’s swampy cities, stories of sewer-dwelling reptiles have fascinated and terrified people for decades. But a recent study conducted in Florida proves that at least sometimes, legends aren’t entirely fiction.

Researchers set up camera traps in stormwater sewer systems and discovered an astonishing variety of wildlife living below the streets. From raccoons to river otters — and yes, even alligators — these underground tunnels are a hidden ecosystem few people ever see.

The research, published in Urban Naturalist, examined vertebrate species inhabiting Florida’s stormwater sewer systems. Specifically, the team focused on Alachua County. Using camera traps in 39 locations, scientists documented an impressive 35 species living in these subterranean channels.

Raccoons were by far the most common sighting, followed by bats. However, researchers also found armadillos, otters, amphibians, and, remarkably, alligators. While some of these animals simply passed through, others seemed to have adapted to using the stormwater systems as a habitat and seemed to be thriving in the sewage.

Why Some Animals Like These Sewers

The sewers were not designed with wildlife in mind, and at first glance, the idea of wildlife thriving in there seems bizarre. However, urban infrastructure inadvertently provides pathways and conditions that animals take advantage of.

It’s important to remember that these are stormwater sewers. Unlike sanitary sewers, which carry human waste, stormwater sewer systems exist to drain rainwater. These open systems connect ponds, creeks, and drainage basins, creating a network of tunnels that mimic natural waterways. Sure, they’re not as nice as natural rivers, but animals like alligators can use these tunnels to navigate between bodies of water nonetheless.

Furthermore, the sewers provide dark and enclosed spaces. Raccoons, bats, and rodents seek out these tunnels for protection from predators and harsh weather conditions. This, in turn, could also draw their predators like alligators to sewer openings. Meanwhile, birds have been observed foraging at sewer pipe exits, presumably drawn by fish.

This study is among the first to explore stormwater sewers as wildlife habitat.

Why This Matters: Urban Wildlife and Conservation

While cities and urban areas are not exactly friendly to wildlife, they can contain habitats that support diverse species. Sewers could play an important role in supporting wildlife, the researchers say.

The presence of so many animals suggests that stormwater sewers act as unintended wildlife corridors. In heavily urbanized areas, these tunnels may be crucial for maintaining connectivity between fragmented habitats. However, not all is well in the sewers.

While these underground habitats provide shelter, they also pose risks. Small animals like amphibians may accidentally fall into storm drains and become trapped. Similarly, larger mammals like raccoons could face dangers from human maintenance work or flooding events. These areas could also be harboring different bacteria or pose other risks and threats.

Understanding how and why animals use sewer systems can help reduce negative interactions. For example, if raccoons and bats are thriving in urban infrastructure, city planners might consider incorporating wildlife-friendly design elements, such as escape ramps for trapped animals. Basically, recognizing stormwater sewers as valuable habitat could inform conservation efforts.

Of course, confirming a famous urban myth is just a bonus.

The Alligator Connection

The idea of sewer alligators has been a part of urban folklore for decades, ranging from New York to Paris. The myth often tells of pet alligators being flushed down toilets, only to grow into monstrous creatures lurking in underground tunnels. While the reality is far less dramatic, alligators do indeed inhabit stormwater sewers in Florida.

In this study, researchers documented alligators in five different sewer locations. These were typically near natural or artificial ponds, indicating that alligators were using the tunnels to move between bodies of water rather than permanently residing underground.

Unlike the exaggerated legends, these alligators are not albino mutants nor are they growing to monstrous sizes in isolation. They also won’t come through your pipes. However, their presence does raise questions about human-wildlife interactions in urban environments.

For now, this is just a preliminary study, and there’s much we don’t know about how wildlife use sewers. Further studies could use GPS tracking and environmental monitoring to gain deeper insights into this hidden ecosystem beneath our feet.

But next time you pass a storm drain in Florida, remember: there might just be an alligator lurking below.

The study has been published in Urban Naturalist.