When Cities and Wetlands Collide

The integration of natural flora and fauna into the cities has been a challenge for architects and planners since the beginning of buildings. The task becomes even more difficult when the urban spaces in question are part of our country’s neglected, post-industrial landscape. The winning entry to the recent Gowanus Lowline Competition explores the process of mending broken pieces of aged, urban fabric while dealing with not only the vacancies created by absent industry, but sites riddled with the environmental scars of a previous era.

The scheme probes at the possibility of new urban spaces, utilizing both natural systems of remediation and the active density of a modern city. Wetlands and cityscape: two realities commonly assumed to be so diametrically opposed that their overlap is all but implausible. The former harnesses natural processes to provide an ecology with no net waste or squandered resources and supports a myriad of species in close proximity. The latter is the function of fabricated infrastructural systems that levy an indisputable tax on natural resources as it bleeds energy to support a single species in close proximity. The prospective benefits of synthesizing the accolades of both environments are far-reaching, but given their respective needs of space and circulation the question becomes, how can these ecologies co-exist without one decimating the function of the other?

The Post-Industrial Canvas

Polluted Industrial Canal

The competition centered on the Gowanus Canal, completed in 1869, one of the countless industrial relics that lay scattered across our country’s cities. When New York was still a city of production, the canal was carved into the heart of lower Brooklyn to allow for sea traffic to pierce deeper into the district of warehouses and factories. Barges could give and take their wares before returning to the bay and beyond, allowing for intra-city commerce to spread further beyond the coastline.  Of course, New York would fall prey to the same forces of industrial decline that befell the rest of the U.S. Much like the Highline, by the 1960’s, the canal was all but useless with fabricators and vendors having left the shores of the East and Hudson rivers for lands of cheaper labor. In time, the bustling warehouses would grow vacant and traffic dwindled down to a crawl.

The life of the canal did not come without costs, however. Throughout its tenure of work, three of the tenants of its banks were coal gas plants; charged with the task of creating synthetic, flammable fuel from coal and served largely as the predecessor of natural gas. One byproduct was a substance called coal tar that was unceremoniously dumped into the canal and its shores for years—and still sits there today along with cement, oil, mercury and lead. Since its inception the Gowanus Canal was also a dumping ground for the sewage of the swiftly growing city around it, constantly battling against concentrations of waste (a battle it is long since lost). It comes as little surprise that the Gowanus Canal has recently landed itself a place on the EPA’s National Priority List, earning the title of one of the most polluted sites of the country. Its waters are so dark and deprived of oxygen that it is virtually unable to sustain life of any kind.

New Fertile Ground

In this project, I had the good fortune of working as part of a great design team including Brandon Specketer, Luke Carnahan and Ryan Doyle. Some of our early inclinations were to craft new urban strategy built around wetland systems that could cleanse the area of the canal over time. Many natural ecosystems contain components that are adept at mitigating pollutants from water, air and soil—particularly wetland environments. These complex combinations of organisms can provide remediation processes that are arguably more successful (and often less expensive) than their manufactured counterparts. On the other hand, the proximity of nearby Prospect Park made it redundant to turn the canal into a park or preserve, potentially inhibiting its ability to contribute to the density of Brooklyn. The challenge presented itself as how to provide remediation for one of the most polluted sites in the country while creating the framework for a pedestrian-driven environment that restores activity and density to a vacant patch of the urban fabric.

The outline of the original estuary over the present day urban fabric

Our process began by looking at the natural estuary that originally formed a series of ponds and creeks that later became the Gowanus Canal. When the outline of the fertile land of the tidal marsh basin was laid over the grid of today, the result boldly highlighted the abrupt change in building scale from tight row houses to large industrial space. The correlation made sense given that the estuary soil was once prime for farming and likely developed long after the surrounding residential neighborhoods. It seemed appropriate to use this violent shift in built form as the definition of our site for a new urban intervention.

“Flowlands” proposes the co-existence of two ecologies that are often thought of as restricted to markedly different locales. The two systems respond to each other much like a double helix—not combined, but rather intertwined; linked through function, but not homogeneous.

The proposed solution integrated layers of urban activity into a wetlands ecology. Using the elevation difference between the canal and the grid of roads around it, the surrounding lots were terraced into a series of levels that stepped down to the water’s edge. Each layer fostered a different micro-climate of wetlands activity that, in turn, provided different methods of remediation. While poplar trees could pull chemicals and heavy metals from the earth by the street, the lowest layer fostered oyster beds that could clean toxins from the canal as one of nature’s most talented water purifiers. Together, the wetland layers work together to clean not only the polluted waters of the canal, but store and filter stormwater runoff to prevent further polluting of the canal via Combined Sewer Overflows (CSOs) (see how much sewage they spit into our country’s waterways).

A diagrammatic section of the proposed wetland and pedestrian systems (click to enlarge)

New pedestrian activity would exist over the more fragile environment of the wetlands by way of a network of elevated thoroughfares that provide access from the streets to the edges of the canal and all points in between. Paths of metal grating allow for movement over natural ecosystems while allowing for air, water and sunlight to penetrate below. Beside each wetland street, strips of greenery are pulled upwards to become green roofs for the retail and commercial space inserted beneath, accessed by the network of public circulation.

The final piece is seven high rise towers of residential space with bases of retail and community program to tie into the green, wetland paths. The towers offer the prospect of a population that can call the neighborhood home, providing a steady stream of pedestrians—the lifeblood of any streetscape. Together, the seven towers can hold enough residents to bring the net population density of the district within striking distance of neighboring Park Slope—yet at the same time operate beneath a layer of  greenscape rather than the impervious layer of tar roofs, asphalt roads and concrete sidewalks.

Though the competition was merely a very schematic attempt at formulating ideas, the possibilities for the interconnections of such a system are boundless. It is easy to imagine geothermal heating and cooling as a key component to both the street level program and the larger towers. The southern face of each residential spire could provide ample square footage for solar panels or hoist wind turbines up hundreds of feet off the ground where wind speed is higher and more consistent. In order to maintain the goals of the community at large, greywater systems could be tied into the various wetland components to filter portions of water on site and provide water for non-potable uses in return. Eventually, these two systems could be woven into a new, unified ecology. This is the mark of the important difference between a truly green city and merely a garden city.

While the Gowanus Canal may epitomize the extreme of polluted, industrial sites, brownfield property is far from a rarity in the U.S., making it important to search for solutions to remediate and repopulate these artifacts so they can contribute to their surroundings once again. Perhaps the most interesting idea that our design team came away with was the opportunity for a new relationship between remediation and urban living. For as much as I praise the Highline (and I do, it is fantastic), it is arguably an industrial relic transformed into a destination that attracts people for an event. Instead of only being a destination icon whose function happens to provide remediation for the area, a new Gowanus neighborhood could make the process of remediation not some distant event that occurs on a separate site or behind tall fences, but outside someone’s front door or next to where you buy food. Having remediation be more of a part of our daily lives could leave us all with more of a reminder and impression as to why the remediation is necessary in the first place.

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