Yes, they really have found alligators in the New York sewer system

An American alligator, presumably planning its next descent into the nation’s sewers. Image: Matthew Field, republished under creative commons.

Urban legends are the modern world’s answer to fairy tales. Both tell of dark and mysterious forces, always inexplicable, always lurking just out of sight. Satanic rituals. Aquatic monsters.  Ships lost at sea in a specific, conveniently geometric area.

And, of course, the New York sewer alligators.

These beasts, so the stories go, were brought back to the city by rich New York families who’d made some poor buying decisions while on vacation in Florida. Once they tired of their new pets – or at least, realised quite how big and hungry they were going to get – the owners would flush them down the toilet. This, at least, is the main explanation given for how so many people claim to have spotted the beasts in New York, a city whose climate is far, far too cold for them.

As with many urban legends, the story persists because it actually seems to have a grain of truth to it. We can’t verify the tales of posh brats flushing innocent baby gators down toilets – but sightings, some verified, some probably made up, have been a feature of the city’s newspapers since the 1930s.

According to the New York Times’ archives, the first sighting of a suspected sewer alligator was in 1932, when one was found lounging on the banks of the Bronx River. The next, and most famous, came three years later, when two teenagers shovelling snow in East Harlem came across one nosing its way out of a manhole. The Times ran an appropriately penny dreadful-esque headline the next day:

"ALLIGATOR FOUND IN UPTOWN SEWER: Youths Shovelling Snow into Manhole See the Animal Churning in Icy Water. SNARE IT AND DRAG IT OUT: Reptile Slain by Rescuers When It Gets Vicious – Whence It Came Is Mystery."

(Yes, that is just the headline.)

Since then, there have been regular stories (how reliable is not entirely clear) of alligators spotted in lakes, reservoirs and rivers near the city. None of them, alas, have matched the high drama of the manhole alligator of ‘35.

A sculpture in a downtown subway station commemorating the emergence of the East Harlem alligator. Image: More than Midtown.

UPDATE, February 2018: A concerned elementary school teacher has been in touch from Maryland, worrying that this article might give impressionable students the wrong idea. So, to clarify: while alligators have often been found in and around New York, it seems unlikely that they lived in the sewers – or at least, not for long, since they'd probably die of cold and disease down there. So, to be clear, when we say a grain of truth, we mean just that. There are not thriving colonies of gators down there, and we never meant to imply that there were. 

Rather than fearing them, New Yorkers seem to view the city’s phantom alligators as a source of pride. For the past four years, every 9th February has seen the celebration of the city’s annual "Alligators in the Sewers Day". Manhattan Borough historian Michael Miscione, who launched the event on the 75th anniversary of the 1935 sighting, claims he created it not to poke fun at the story, but to emphasise its veracity: “The concept of alligators in city sewers is a great myth, and, having done a little research on it, I found that it has a strong basis in reality. I felt people should know that.” At this year’s event, there were speakers and a quiz, and the first 100 guests received a free plastic baby alligator.

The New York obsession with alligators seems all the stranger when you consider the fact that smaller reptiles very definitely are swimming around beneath the city’s streets, and no one seems very concerned about them. Snapping turtles are regularly spotted in sewage treatment systems but, for Miscione, they simply don’t have the same appeal. “They’re not nearly as exotic or dangerous as alligators, and they’re native to this area, so what’s the big deal?” he asks. “No one cares about snapping turtles.” The state's lawmakers don't agree: in 2006 they designated the snapping turtle the official state animal. 


The alligator story has also imprinted itself, albeit less deeply, on Paris. In 1984, sewer workers under the Pont Neuf Bridge found a Nile alligator, which had supposedly been eating rubbish and rats to survive. It was christened Eleanore and still resides in an aquarium in the city of Vannes. (In true Parisian style, the city has yet to celebrate anything as undignified as an Alligators in the Sewers Day.)

In London, there are no alligators that we know of, and fears instead tend to focus on giant rats – perhaps not surprisingly, since they carried the Bubonic Plague that managed to wipe out half the city’s population in the 14th century.

Modern stories about rats, however, have tended to eschew the threat of a new plague, and focus instead on the risk of them growing to giant proportions before emerging from the sewers to wreak havoc. The most recent prediction of a mutant rat invasion from below the city’s streets came in February, when Rentokil, the aptly named pest control company, told the London Metro that 10 inch-long sewer rats, able to spawn 200 young in a single year, would soon take over the capital.

You’ll be pleased to hear that these reports proved unfounded (so far, at least). But there are reasons to believe that sewer rats are getting bigger, thanks, perhaps unexpectedly, to an increase in recycling. We now rinse packaging out, rather than letting food scraps go to landfill: that gives sewer rats a more plentiful food supply.

As with New York’s alligators, this problem is apparently the fault of a particular class. In Elton’s Ecologists, a history of the now-defunct Oxford Bureau of Animal Population, author Peter Crowcroft blames the apartment-dwelling middle classes for feeding the sewer rats:

“Sewer rats do well in areas which are thickly populated by humans who are neither very rich nor very poor. Such people, especially apartment dwellers, tend to waste food, often flushing it into the drains in useful fragments, instead of converting it into an unavailable sludge with grinding machines installed in sinks.” 

So, when the mutant rats really do take over, we’ll know who to blame.

 
 
 
 

Green roofs improve cities – so why don’t all buildings have them?

The green roof at the Kennedy Centre, Washington DC. Image: Getty.

Rooftops covered with grass, vegetable gardens and lush foliage are now a common sight in many cities around the world. More and more private companies and city authorities are investing in green roofs, drawn to their wide-ranging benefits which include savings on energy costs, mitigating the risk from floods, creating habitats for urban wildlife, tackling air pollution and urban heat and even producing food.

A recent report in the UK suggested that the green roof market there is expanding at a rate of 17 per cent each year. The world’s largest rooftop farm will open in Paris in 2020, superseding similar schemes in New York City and Chicago. Stuttgart, in Germany, is thought of as “the green roof capital of Europe”, while Singapore is even installing green roofs on buses.

These increasingly radical urban designs can help cities adapt to the monumental challenges they face, such as access to resources and a lack of green space due to development. But buy-in from city authorities, businesses and other institutions is crucial to ensuring their success – as is research investigating different options to suit the variety of rooftop spaces found in cities.

A growing trend

The UK is relatively new to developing green roofs, and governments and institutions are playing a major role in spreading the practice. London is home to much of the UK’s green roof market, mainly due to forward-thinking policies such as the 2008 London Plan, which paved the way to more than double the area of green roofs in the capital.

Although London has led the way, there are now “living labs” at the Universities of Sheffield and Salford which are helping to establish the precedent elsewhere. The IGNITION project – led by the Greater Manchester Combined Authority – involves the development of a living lab at the University of Salford, with the aim of uncovering ways to convince developers and investors to adopt green roofs.

Ongoing research is showcasing how green roofs can integrate with living walls and sustainable drainage systems on the ground, such as street trees, to better manage water and make the built environment more sustainable.

Research is also demonstrating the social value of green roofs. Doctors are increasingly prescribing time spent gardening outdoors for patients dealiong with anxiety and depression. And research has found that access to even the most basic green spaces can provide a better quality of life for dementia sufferers and help prevent obesity.

An edible roof at Fenway Park, stadium of the Boston Red Sox. Image: Michael Hardman/author provided.

In North America, green roofs have become mainstream, with a wide array of expansive, accessible and food-producing roofs installed in buildings. Again, city leaders and authorities have helped push the movement forward – only recently, San Francisco created a policy requiring new buildings to have green roofs. Toronto has policies dating from the 1990s, encouraging the development of urban farms on rooftops.

These countries also benefit from having newer buildings, which make it easier to install green roofs. Being able to store and distribute water right across the rooftop is crucial to maintaining the plants on any green roof – especially on “edible roofs” which farm fruit and vegetables. And it’s much easier to create this capacity in newer buildings, which can typically hold greater weight, than retro-fit old ones. Having a stronger roof also makes it easier to grow a greater variety of plants, since the soil can be deeper.


The new normal?

For green roofs to become the norm for new developments, there needs to be buy-in from public authorities and private actors. Those responsible for maintaining buildings may have to acquire new skills, such as landscaping, and in some cases volunteers may be needed to help out. Other considerations include installing drainage paths, meeting health and safety requirements and perhaps allowing access for the public, as well as planning restrictions and disruption from regular ativities in and around the buildings during installation.

To convince investors and developers that installing green roofs is worthwhile, economic arguments are still the most important. The term “natural capital” has been developed to explain the economic value of nature; for example, measuring the money saved by installing natural solutions to protect against flood damage, adapt to climate change or help people lead healthier and happier lives.

As the expertise about green roofs grows, official standards have been developed to ensure that they are designed, built and maintained properly, and function well. Improvements in the science and technology underpinning green roof development have also led to new variations on the concept.

For example, “blue roofs” increase the capacity of buildings to hold water over longer periods of time, rather than drain away quickly – crucial in times of heavier rainfall. There are also combinations of green roofs with solar panels, and “brown roofs” which are wilder in nature and maximise biodiversity.

If the trend continues, it could create new jobs and a more vibrant and sustainable local food economy – alongside many other benefits. There are still barriers to overcome, but the evidence so far indicates that green roofs have the potential to transform cities and help them function sustainably long into the future. The success stories need to be studied and replicated elsewhere, to make green, blue, brown and food-producing roofs the norm in cities around the world.

Michael Hardman, Senior Lecturer in Urban Geography, University of Salford and Nick Davies, Research Fellow, University of Salford.

This article is republished from The Conversation under a Creative Commons license. Read the original article.