Welcome back to Camera Obscura, Curbed's series of photo essays by Nathan Kensinger. This week, examining a new book about the Gowanus Canal.

On a recent balmy afternoon, Joseph Alexiou clambered down a ladder on the side of the Union Street Bridge. At the bottom was a small platform, coated in layers of raw sewage, industrial pollutants and rusted blue-green paint. Clouds of fecal matter and rainbow-patterned oil slicks floated slowly by, drawing the eye upstream to their source. The view was hemmed in by graffiti covered warehouses and a decrepit fuel depot, but the churning, noxious headwaters of the Gowanus Canal could be seen nearby. It was a vista with its own unique appeal, enjoyed that day by only a few other Brooklyn visitors. "Can you go swimming in it?" asked one, a local high school student who had taken up a position on the opposite footing. "You could probably go swimming once and be fine," replied Alexiou. "But I wouldn't do it myself, having learned the history of it. I would go to an emergency room, and I would make sure to get antibiotics."

The allure of the Gowanus Canal is one of the great mysteries of South Brooklyn, and Joseph Alexiou has been pulled deeply into the powerful eddies of this diminutive 1.8-mile waterway. Last Friday, he launched the results of his years-long infatuation, a 398-page book titled Gowanus: Brooklyn's Curious Canal. Like the Gowanus itself, this densely packed historical narrative meanders through many unexpected twists and turns, sometimes reaching dead ends and sometimes revealing unexpected perspectives, as it explores this peculiar landscape of industrial relics and horrendous pollution. Along the way, it visits with poisoned whales, forgotten islands, vanished shanty towns, mass graves from the Revolutionary War, and a roster of strange local characters—the artists, poets, activists, and gangsters who, even today, add to the canal's quirky charm. "I became obsessed with the word Gowanus and then turned it into a story," said Alexiou, describing his research and writing process. "The more I looked, the more there was."

During his years of research, Joseph Alexiou uncovered many things, including the numerous names the Gowanus has had over the centuries. Its origins are murky, but early variations included Cujanes, Cowanoes, Gauwanes, Gouanes, and Gouwanes, and, as the waterway evolved from a wild marshland to a polluted industrial canal, it has been called The Lavender Lake, Fringeville, a toxic wasteland, a Stygian mess, a swampy morass, and an open sewer. One of the threads tying the canal's complicated narrative together is its history of conflict between pollution and privilege, rich and poor, and Alexiou's account of its transformation begins with Brooklyn's earliest European settlers, Dutch landowners who used African slaves to dig out the banks of the Gowanus Creek, creating a system of tidal millponds. These initial interventions were soon followed by successive waves of wealthy developers and corrupt politicians, each adding their part to help turn the Gowanus into a modern Superfund site. Of the many individuals responsible for this twisted waterway, Alexiou focuses in particular on the history of Daniel Richards, a wealthy businessman and politician who created a plan for the modern Gowanus Canal in the 1840s, and Edwin Litchfield, a fabulously wealthy railroad baron who used his riches to buy up a square mile of waterfront property in the 1850s, before developing it into the neighborhood known today as Park Slope. "All of this is inspired by what happened during that time," said Alexiou. "The Gilded Age, a time when technology was being rapidly made, improved, and tested, almost dangerously so."

The book especially comes to life when it delves into the stories of the many working class residents and low-income communities that once called the Gowanus home. From the constantly flooded shanty dwellings of Darby's Patch, Tinkersville, and Gowanus Beach to fishermen riding swimming pigs home after a day of leisure on Dowd's Island, the author's prodigious research has dredged up some true pearls. "If I could have, I would have just stood at the corner of a street there for 300 years. That's what I was trying to achieve," said Alexiou, who became interested in the canal when he moved to its western banks in 2006. "Because I was here, I saw things change," he recalled. "I started meeting people who had been in the neighborhood for years." Some of those same neighbors are included the book, while an assortment of older characters also make appearances, from famed gangsters like "Scarface" Al Capone and "Crazy Joe" Gallo to neighborhood celebrities like Michael Shay—an 1800s poet known to locals as "The Gas Drip Bard," and "Dotty" Bennett—author of Sold to the Ladies!, a 1940 book about her adventures transforming a welding barge into a summer houseboat on the Gowanus. Alexiou's research makes it clear that the canal has been a source of inspiration for generations of artists, outsiders, outlaws, and other assorted Gowanusians.

As one of those Brooklyn residents inspired by the canal, I read Gowanus: Brooklyn's Curious Canal with keen interest. While living just a few blocks from the canal, I too was drawn to explore its waters, and have canoed and hiked every inch of its length, photographing its industrial ruins, creating art installations along its shores, and adding my work to the Hall of Gowanus. For the past decade, I've documented how the canal has transitioned from a neglected waterway into a Federal Superfund site, and have chronicled recent developments along its banks, as historic buildings are demolished, artists are forced out, and developers are once again given free rein to reshape the waterway. However, it was not until reading Alexiou's book that I gained a full appreciation of the canal's place in the scope of New York's history. Now, a walk along the canal from head to mouth reveals many new layers of complex history.

The familiar tensions between rich and poor are still present on the Gowanus today, as new residential towers spring up along its shoreline and unfiltered sewage continues to be dumped into its waters, an environmental injustice that the city has avoided addressing since the 1800s. But, after many decades of ignoring the canal, the government has recently begun work on the Superfund cleanup process. As the latest transformation of the Gowanus continues, Alexiou's book is a timely record of the permanent impact humans have had on the area, even as it faces an uncertain future shaped by climate change and rising sea levels. "What happens in industrial neighborhoods across New York is going to be based off the kinds of things that happen here," said Alexiou, contemplating the canal. "The ultimate fight with Gowanus—and this is true of urban landscapes in general—is that we are constantly fighting against nature, we just don't think about it…At some point that water is going to win, its just a matter of time."

Up at the head of the Gowanus Canal, a pumping station and flushing tunnel dating back to 1911 are still in use today, a century old design that was meant to bring fresh water to the canal's putrescent stagnation. "You'll see it frothed up sometimes, and sometimes there is this film. The DEP and the city claim that that is just normal, whereas the EPA says no, that's a sign of pollution," said Alexiou. "They don't agree on this."

"That is also actually the exit of the Greene Avenue sewer main, which is addressed in the book," said Alexiou. "The canal had the dual purpose of being a shipping lane and a drain for flooding. It was never intended to be a sewer. That was something that the city did as a temporary measure that they still have yet to fix… and in fact those holes at the end of the Greene Avenue sewer main are some of the most polluting parts of the canal."

Today, fish and other wildlife can be seen in the canal's water, which would have been unheard of 20 years ago. "After nearly forty years of inactivity, the Gowanus Canal flushing tunnel was activated the first of May 1999," wrote Alexiou. "'Prior to the flushing tunnel, a dead dog would just float back and forth with the tides between Third Street and Carroll for maybe a week,' David Lefkowitz, a real estate investor, told the New York Times. 'Now, the thing could be gone in maybe 24 hours.'"

At low tide, rats and birds search the polluted sediment for sustenance. The canal, however, does appear to be cleaner, especially after a recent $177 million upgrade to the flushing tunnel. "The way that the EPA is planning to deal with the sewer issue," said Alexiou, "is building a retention basin, which is supposed to catch the extra raw sewage during times of overflow."

The entire length of the Gowanus is currently lined with Combined Sewer Overflows (CSOs), where raw sewage dumps out during rain storms. "No matter how it might be modified, the Gowanus remains the site of a wetland at one of the lowest elevations in Brooklyn—a collection point of a grand watershed. Only the monumental, astronomically expensive effort of engineering could change this fact of geography, and so during the greatest rainstorms, swelling tidewaters fill the main and lateral sewer pipes. Once these are full, the waters fill area basements—a fact of nineteenth-century life that continues today," writes Alexiou.

Just up the canal from one of the most polluting CSOs on the Gowanus lies the new Whole Foods Market. Located across the street from a historic 1890s power station—a neighborhood icon known as The Batcave—the market faces a ragged shoreline where some of the only plant life growing in the canal is maintained by the Gowanus Canal Conservancy. It is a small reminder of when "Gowanus was a wild and bountiful place, full of salt marshes and forests—yet still a quick boat ride from Manhattan," wrote Alexiou, describing a period of "seventeenth-century pastoral bliss."

Whole Foods has an esplanade and dining area which look out over the canal's waters, a fact recently mocked on the cover of The New Yorker. "Another vestige, that we may not realize, of 19th century urban planning is next to the Whole Foods, in that basin, the 4th Street basin," said Alexiou. "In the book, I have quotes about that very basin being especially polluted, with horse bones, dead cats, animal carcasses and slop and human shit."

"As far as things from the 19th century," said Alexiou, "probably the most important of those buildings is the Coignet building, which is landmarked, so it is protected." Unveiled last week after a lengthy renovation, the building dates back to 1872, and was meant as a showcase for the possibilities of coignet stone, a precursor to concrete. It is now surrounded by the Whole Foods campus.

On the canal's west side, one of the area's last historic single-story residences remains. Built in 1897, this wood-framed structure was once typical in the shanty towns and lower income neighborhoods that lined the canal's banks, but now it's a rarity. "The toxicity of the canal kept developers at bay for a long time," said homeowner Martin Bansbach. "But now that the EPA said they are going to do something, it's getting developed."

By contrast, the new Lightstone towers being constructed at the edge of the canal will be 12 stories high. "They want to build tall, and they want to build expensively, and they want to build in a place where we know that the sewers connect directly to the open air," said Alexiou. "It is a systemic process, and the city thinks that it can make the most money by doing real estate in a certain way... but it's really stupid to do that next to a toxic waste site."

Further down the canal, an active scrap company still uses barges, another increasingly rare sight. "The Gowanus Bay was awfully crowded in 1928," writes Alexiou. "More than twenty-six thousand barges, boats and other vessels would pass under the Hamilton Street bridge, the unofficial entrance of this ancient boat channel, at the height of its career. Nearly fifty different industrial firms and warehouse businesses could be found along the banks of the canal: lumber, sand, and stone yards, gas manufacturing and coal processing plants, ice houses, chemical dye factories, concrete works, and tile factories."

Today, many fewer businesses in the area use the waterway. "At the beginning of the Second World War, approximately eighteen thousand vessels entered the Gowanus Canal annually, a marked drop from the heyday of the late 1920s. By the early 1950s, the number plunged again to ten thousand; by the 1960s, so much boat traffic had been lost that the Army Corps of Engineers did not bother to gather statistics at all."

Along the southern end of the Gowanus Canal lies another 19th century landmark, the long-abandoned S. W. Bowne Grain Storehouse, which was built in 1886. The building has been left to the elements, its roof slowly collapsing in two places.

The interior of the warehouse is in remarkably stable condition, with thick wooden beams supporting an enormous, open interior, although graffiti covers most of the walls, a sign of its dangerous abandonment.

"Unlike the classic Brooklyn stores design, this storehouse is unique in having a gabled, rather than a flat, roof," according to the Municipal Art Society. "This storehouse is one of few distinctly 19th-century structures remaining on the canal and one of the most visually intact canalside structures linked to the canal's role in the growth of Brooklyn."

Outside, near the mouth of the Gowanus Canal, an overgrown, unused shoreline faces the newly rebuilt Hamilton Avenue Asphalt Plant and Hamilton Avenue Marine Transfer Station, signs of the city's continued dedication to keeping at least part of the canal as a working waterfront. It was in these same waters that Sludgie The Whale met his untimely demise in 2007.

The old grain terminal on the Gowanus Bay, another long abandoned industrial relic. Sludgie The Whale was first spotted in the waters near here, according to Alexiou's book, after a record rainfall flooded the Gowanus with sewage. Just a day into her misadventure, "a witness saw Sludgie thrashing in the water near the mouth of the canal. She then beached herself onto some rocks and, quite suddenly and to the disappointment of many, died just before five o'clock, only a single day into her celebrity."

At the end of the Gowanus Canal lies the Gowanus Bay Terminal, formerly home to Dowd's Island, an 1830s shanty town which was "a choice locale for catching wild ducks and snipe," writes Alexiou. Today, this industrialized inlet is off limits, with signs sunk in the water reading "Posted - Private Property - hunting, fishing, trapping or trespassing for any purpose is strictly forbidden - violators will be prosecuted," a fitting reminder of the ongoing struggle between man, nature and developers along the Gowanus.

· Nathan Kensinger [Official]

· Camera Obscura archive [Curbed]

· Gowanus Canal coverage [Curbed]