Along the Gowanus Canal in Brooklyn, a 118-year-old power station has become Powerhouse Arts, a contemporary arts and fabrication space. To protect its waterfront from storm surges and sea level rise, landscape architecture firm Ken Smith Workshop layered in steel sheet and concrete block defenses. But they also wove in a nature-based solution to capture stormwater. “It’s both a living shoreline and defensive measure that will make the site adaptable,” said Ken Smith, FASLA. “It’s how we could use a tight space with a steep slope to do a lot.”
The power station, built at the turn of the 20th century, once housed coal-powered turbines for generating electricity. The three-story red brick building was developed by the Brooklyn Rapid Transit Company and then decommissioned in the late 1930s. A few decades later, it was reborn as a cardboard incinerating facility. Since then, it has had many lives, becoming home to artists and squatters. Some of the city’s best graffiti artists left their mark. And in recent decades, it became known as the Batcave, a place for dance parties.
After starting a foundation, hedge funder Joshua Rechnitz purchased the building in 2012 and then hired architects Herzog & de Meuron and PBDW to renovate the power station and graph on a six-story annex, essentially doubling the square footage. “They brought rigor to the project, maintaining the architecture in as straightforward a way as possible,” Smith said during our hard hat tour.
The foundation and architects re-imagined the space as a sophisticated artist and fabrication studio that will offer community classes, prototyping spaces, job training, and public exhibitions. But they also wanted to keep its layers of history, including the graffiti.
Exiting the rear of the Powerhouse, the expanse of the Gowanus Canal, one of the most contaminated Superfund sites in the country, came into view. It’s a water body that also continues to receive millions of gallons of combined sewer overflow each year.
The canal has drawn in number of landscape architects over the years. Susannah Drake, FASLA, and her firm DLANDStudio, created the Gowanus Canal Sponge Park™. That began as a plan for lining the 1.5-mile-long canal with absorbent green spaces that could reduce stormwater from further polluting the waterway. An 1,800-square feet pilot sponge park was then completed in 2016 and now captures some 2 million gallons of stormwater each year.
And in 2018, SCAPE Landscape Architecture partnered with the community to create the Gowanus Lowlands Masterplan, a vision for restoring public spaces and the ecology of the canal and its watershed. SCAPE dove into the history of the Gowanus Creek ecosystem that once existed. In the 1850s, the creek was hardened, becoming what is is today — a canal for transportation and industrial manufacturing.
Smith said that during Hurricane Irene, which pummeled the city in 2011, the canal’s polluted waters rose up by 16 feet, flooding the area. Working with limited space, he decided to reinforce the Powerhouse Arts waterfront with steel sea wall and concrete yard blocks, protecting it from future storm and climate impacts. “The site was raised considerably. To be good citizens, we went with armature.”
Before Smith began his work, the existing waterfront edge was 5.8 feet above sea level, so not enough to protect against a future storm surge. Working with the engineering team, Smith brought in 225 feet of black steel sheet pile walls, which were driven 40 feet down into the canal bank. The top of the new sheet pile sea wall is now 10 feet above sea level — higher but not enough for the greatest storm surges.
Behind the sea wall, Smith wove in 12-foot-wide gravel walkway, ensuring public access to the waterfront. From the back of that path, stepped rows of concrete yard block walls add another 12.75 feet of protection. The 366 concrete yard blocks, sometimes called “mafia blocks,” are lined up in precise rows. The top of the slope is now 19.5 feet above sea level.
Smith said he also used materials like steel and concrete because he wanted to maintain the site’s “industrial vocabulary.”
He sees potential in this humble grey infrastructure: “Gabions used to be utilitarian; now they are quite fetishized. Concrete yard blocks will become the next gabion.”
The blocks were also purposefully positioned so they are multi-functional: “They are usable; you can sit on them.”
Above the blocks is a vegetated buffer filled with trees and meadow grasses that will capture water coming from the Powerhouse parking lot. “The beach plum, coffee, and red cedar trees are tough” and will ensure that living shoreline element will endure.
Boulders were plopped randomly to offset the rectilinear building. “I didn’t want the landscape to be too straight forward and direct. I wanted to create an interesting frame for the building.”
Crossing a bridge to the other side of the canal, Smith remarked that the canal is a highly polluted place that is being rapidly re-zoned as a residential area.
Standing at the Sponge Park, and looking across the canal at Powerhouse Arts, one could see a variety of waterfront landscapes — some clearly green spaces associated with residences, some public spaces, and some linked with legacy manufacturing sites. The piece-meal approach to waterfront resilience in NYC was apparent.
Nature-based solutions to storm surges, such as mangroves and wetlands, are ideal but require large set-backs on-shore. Constructed islands, berms, and reefs can reduce wave power from storm surges off-shore but require enough space in the water and distance from the shore.
What is the solution along highly developed canals and rivers where deep set-backs or offshore solutions aren’t possible? In many places, New York City has been lifting up, adding elevated park structures as well as sea walls to its waterfront. The Powerhouse Arts project says here, at least along this stretch of canal, resilience means armor. But this just means the storm will surge in elsewhere.