Planner Push for a New Green Space in Tribeca, to Double as Resiliency Boost
The husband-and-wife architecture team of Dasha Khapalova and Peter Ballman have revised their 2020 proposal to create a new park surrounding the Holland Tunnel Rotary, the six-acre asphalt gyre of exit ramps that connects traffic from New Jersey to Lower Manhattan’s street grid.
While the original plan called for a constellation of small, street-level parks at the corners of the complex (bounded by Hudson, Laight, and Varick Streets, and Ericsson Place) encompassing a new, submerged central plaza, the updated proposal envisions converting the central 1.5-acre plaza into a resilient “greenscape” planted with native shrubs and grasses, and described as a sponge, to address the acute environmental challenges at that location.
A subsequent phase would transform the perimeter of the facility into a similarly resilient greenscape, which would be accessible (unlike the center, closed to the public for decades owing to security concerns).
Such a revamp is potentially transformative, because each acre of concrete hardscape —which currently covers 96 percent of the Holland Tunnel Rotary—generates more than 100,000 gallons of runoff during a four-inch rain event. For this location, that amount translates into half a million gallons, or more than the capacity of an Olympic-size swimming pool. But this output drops by almost 90 percent when the same land is covered by grass, shrubs, and trees.
The new plan from Ms. Khapalova and Mr. Bellman would also utilize the space beneath the central plaza as an underground catch basin to capture more water and filter out pollutants before discharging the effluent into the City’s storm drain system.
“They want to transform the Holland Rotary into an environmental asset, a public amenity, and a piece of vibrant and green infrastructure,” explained Alice Blank, chair of the Environmental Protection Committee of Community Board 1 (CB1) at that panel’s September meeting.
CB1 member Jarad Sheer added, “the idea here is to take the space, which is a very large expanse of gravel, and add a green asset for the community. In a city where utility and value are eked out in some form or another from every square foot, how do we have five-plus in the middle of Lower Manhattan essentially sitting there, serving no actual functional purpose?”
On September 26, the full Board of CB1 enthusiastically approved of the proposal. The Board’s resolution noted that multiple agencies have jurisdiction over the rotary, including the Port Authority of New York and New Jersey, and the NYC Departments of Transportation and Parks and Recreation, all of which need to sign off on the plans.
The same resolution urged the designers to incorporate the high-density planting of “mini-forests”—also known as the Miyawaki Method, which emphasizes the cultivation of fast-growing groves of native plants with dense, mixed agronomy that aims to simulate the layers of a natural forest. Miyawaki proponents say this approach achieves growth ten times faster than naturally occurring urban forests, with 20 times the biodiversity and 30 times the bio-density. The result is highly beneficial for air quality issues, as well as flooding.