Conceived of by artist Mary Mattingly, “Swale” models what New York City might look like if food were considered not only an economic good, but a public one.

When I arrived at “Swale” — a rusting barge/shipping container mashup docked at Brooklyn Bridge Park, in the shadow of Lower Manhattan — artists Mary Mattingly and Kim Darling asked me if I would like some tea. It was a chilly, soggy day, and we would be sitting in an open-sided shelter for the next hour or so while talking. Tea sounded nice.

“Want me to get the spearmint?,” Darling asked. She walked over to a nearby garden bed and pulled a heaping fistful of green stems and leaves from the dirt. Returning promptly, she handed it to Mattingly, who placed it in an electric kettle with water. We had tea.

At “Swale,” you don’t buy your food or even barter for it; you pull it out of the ground for free. Conceived of by Mattingly and executed collaboratively with a large number of people and organizations — the website lists “27 partner individuals and organizations” and 24 members of the “team” besides Mattingly — “Swale” is a floating food forest, a simultaneous dream and physical manifestation of what New York City might look like if food were considered not only an economic good, but a public one.

“I want to express that food can be a commons,” said Mattingly. “Why is food just a commodity, here in New York? Why is it just for sale? It’s been privatized, and we could probably bring it back, if we had enough people.”

Mattingly has a penchant for the utopian. For her “Waterpod” project, she designed “a floating eco-habitat” that contained private living spaces, a public dome, as well as food, water, and energy systems; set on a barge, “Waterpod” floated around New York City’s aquatic environs in the summer and fall of 2009. Five years later, she took to the Delaware River to launch “WetLand,” a floating sculpture and self-sustaining ecosystem that expanded upon the innovations of “Waterpod.” In between, she designed a series of “Flock Houses,” mobile living spheres made from reclaimed materials that were sited temporarily in spots throughout New York City.

All of these projects contained edible gardens in some form — “WetLand” hosted chickens and bees as well — and both “Waterpod” and “WetLand” were aquatic structures. In these aspects, they anticipated “Swale”; however, “this is the one that’s really public,” explained Mattingly. Whereas the previous works cultivated living spaces alongside natural systems, with “Swale,” the focus is simpler and more singular: food.

“This is a much more pared-down system and easier to care for,” said Mattingly.

That may be true, but it sounds almost laughable when you start to learn about the project. Spread across a 130-by-40-foot vessel built from repurposed shipping containers (and pulled by tugboat), “Swale” looks familiar and simple enough, like a well-landscaped community garden in which the mulch or grass between plots has been replaced with gravel. But as Mattingly explained, there are three sophisticated systems at work: a solar one, in which five solar panels and 12 marine-grade batteries power everything from a water pump to lights and electronics; a water system, which involves the collection and cleaning of river water, as well as some storage and use of rainwater; and the food system, which means not only the plants themselves — dozens of them, from brussels sprouts to blueberries and wild ginger to oregano — but also sensors that monitor the soil. Those sensors, along with the small architectural structure aboard “Swale,” were installed by the collaborative group Biome Arts, whose members turn the collected data into visualizations that are projected onto the garden at night.

On its website, “Swale” is identified as “a sculpture and a tool,” but, as a work of art, the floating food forest falls squarely in the realm of social practice. “I think it’s art because it’s a proposition,” explained Mattingly, who cited Rebecca Gomperts’s abortion clinic–at-sea, Women on Waves, as an inspiration. “It’s experiential in a way that brings home the proposition.” In other words, although the food is entirely free, the goal is not to feed as many people as possible — Mattingly estimates about 50,000 visitors since the project launched on July 23 — but rather to model the possibility of foraging in New York City. It’s both a symbolic food forest and an actual one.

“It’s so litigious here [in NYC] that it happens to be utopian,” Mattingly continued. “Anywhere else it wouldn’t be. Other cities are not as litigious about food in public spaces.”

Indeed, other metropolises around the world have taken variously sized steps toward embracing food forests; Mattingly cited Seattle’s Beacon Food Forest as an example. But thanks to an old New York City Parks regulation that prohibits “destruction or abuse of trees, plants, flowers, shrubs, and grass,” people are not allowed to pick food off of public land in this city. Hence why “Swale,” like Women on Waves, is located on the water — another commons, and one which Mattingly has returned to in her work, time and again, as a place of possibility.

It seems unlikely that NYC Parks will change its rules anytime soon, but there are signs that the department’s thinking is evolving. Mattingly said she has heard talk of installing signs in public parks that explain which part of a nearby plant is edible, and she’s in conversation with the department herself about a plan that would involve its helping to fund and run “Swale” for five years.

“Keeping this going is necessary, and figuring out how to make it sustainable,” she said. “What is success or failure in a project like this? I think it would be a failure if it didn’t keep going.”

Many visitors would likely agree. Darling and Mattingly spoke of the countless people who boarded “Swale” in its three locations this summer — at Concrete Plant Park in the Bronx, along the shore of Governors Island, and now, at Brooklyn Bridge Park — and were enchanted by it, from the Brooklyn Heights girl who came to pick celery for her guinea pig to the Bronx families who returned to the forest multiple times, bringing additional crops to plant.

And it is enthralling — to be confronted with so much food, and to consider what you might eat, and to then figure out how to pick it, and to take it home for free. When we finished talking, Darling and Mattingly took me around “Swale” to gather tomatillos, kale, bok choy, beans, and more. Even though we had been been discussing this for nearly two hours — at one point, Mattingly had in fact said, “It’s interesting how people are afraid to take things” — I still found myself asking “are you sure?” each time they helped me pick more plants. Even if you’re used to gardening (I’m not), chances are you’re not used to food being given away for free. It’s one of several romantic and radical propositions floated by “Swale,” and as you walk away with your bag full of edibles, you just might find it growing on you.

Just spent two wet, wonderful hours aboard the floating food forest @swaleproject with @marymattingly and @kimdahling. Here’s what I foraged. I cannot wait to dig in. A photo posted by Jillian Steinhauer (@jilnotjill) on Sep 30, 2016 at 3:12pm PDT

“Swale” is docked at Pier 6 in Brooklyn Bridge Park (nearest intersection is Joralemon and Furman streets, Brooklyn Heights) until November 15.