Courtney Koslow pried the tip of a crowbar under the slab of asphalt, then lifted it just enough for her partner to slide a wooden block under it. Then she grabbed the sledgehammer.
Thunk! The first blow resonated. Thunk! Then, on the third hit, she smashed through. The rectangle broke into pieces. Around her, fellow volunteers cheered.
It was a small victory, but combined with dozens like it, that ceremonial smash helped reclaim about 400 square feet of green space in a backyard in Somerville, a city that is 77 percent paved over. A few blocks away, behind another Winter Hill house, volunteers cleared about 200 square feet of asphalt.
They called it De-paving the Way, and for the 40-plus people who took part, it was at once a global gesture and a practical attempt to address local problems.
Organized by Somerville Climate Action, Monday’s event was one of thousands of “work parties’’ coordi nated by activist Bill McKibben’s 350.org to raise awareness of envi ronmental issues. It was also the first of what some hope will be many “de-pavings’’ in private and public spaces.
“It’s really struck a chord,’’ said Vanessa Rule, who led the project. “I think there’s something really empowering about literally taking things into your own hands and restoring your community.’’
The two backyards were “a test case,’’ she said, and the response was so strong that Somerville Climate Action and partners are looking for new sites.
“The enthusiasm is palpable,’’ Rule said. “We’ve gotten so much great feedback. . . . It’s a great way to raise visibility in a way that addresses so many angles — health, flooding, food, creating peaceful places, cooling the city.’’
De-paving has taken off in many other areas. In the Bronx, teenagers tore up the asphalt in a park to plant vegetables. In Seattle, gardeners claimed a traffic median. In Houston, a nonprofit group is turning paved schoolyards into public parks. In Davenport, Iowa, a downtown parking lot is being turned into a fruit and nut orchard. And in Boston’s Mission Hill neighborhood, Calumet Square is being reclaimed for green space.
In many cases, the de-paving is left to professionals — it’s rough work, after all, and asphalt isn’t easy to dispose of. But in Portland, Ore., one group has reclaimed more than 50,000 square feet since 2007 with only volunteers.
“De-paving is really not that hard,’’ said Maren Murphy, a leader of Depave, a Portland-based volunteer group that forms partnerships with municipal officials, schools, and churches to create new public parks and gardens. The group, with no paid staff, is backed by the sustainable-living nonprofit City Repair; for project expenses, it relies on grants and donations.
Portland requires a permit for de-paving, she said, so Depave works with property owners to develop site plans, file the paperwork, and apply for grants. Sites are identified months in advance, so there’s time to prepare and to build up community support
A week before the de-paving, project leaders cut the surface with a diamond saw, leaving “brownies’’ for the volunteers to lift out. The actual removal can take hours or days, depending on the size of the space and the thickness and age of the pavement. The waste is hauled off and recycled; the site is then cleaned, and new soil is brought in.
Altogether, Murphy said, the cost is 75 cents to $1 per square foot — and worth every penny.
“Living in the Northwest, we get a lot of rain, and pavement contributes to storm-water pollution,’’ she said. “But also, when you see pavement all over the place, you get disconnected from nature and from your surroundings, so it’s kind of a small way to do something positive, to re-green the city, and bring nature back into the city.’’
The Somerville group had never heard of Depave when it came up with its plan. Three members were sitting in a cafe, tossing about ideas for a 350.org event, and they laughed at the thought of smashing some pavement to vent their frustrations. And yet, they asked, what if they actually tried it?
“We always talk about having more green space,’’ said Melissa Lowitz, who made the suggestion. “It’s kind of a no-brainer, but nobody thinks of it.’’
Doing a Web search for logo ideas, Rule discovered Depave.org, the Portland group’s site, which became a major resource for her team, providing everything from planning tips, to a list of useful tools, to step-by-step de-paving instructions.
Other local groups agreed to help, including Groundwork Somerville, which enlists local youth to plant gardens in the city, and the Mystic River Watershed Association.
“This is key to solving urban runoff, which is one of the biggest sources of pollution for the Mystic River,’’ said board president John Reinhardt, who volunteered at the event. “In the city of Somerville, there are so many yards that are paved from border to border. While this is symbolic, it’s important for people to start seeing it. I hope it will take off.’’
City officials embraced the idea, as well. Somerville has done some de-paving already, and the Board of Aldermen is considering measures to discourage paving and promote de-paving, prompted by the devastating floods of this spring and summer.
More than three-quarters of Somerville is paved over, according to the Charles River Watershed Association, compared with 56 percent of Boston. The city spends $11 million per year on storm-water treatment, said Alderwoman Rebekah Gewirtz.
Alderwoman Maryann M. Heuston, who represents Winter Hill, had tried to find a public site for the group to dig up. Still, she and Gewirtz helped on Monday, and Heuston said she hopes to compile a list of sites that residents want to de-pave, to have the city do the work.
“People can’t do it all themselves, because it’s not as easy as it sounds,’’ Heuston said.
Indeed, this week’s event wasn’t without its challenges. Each homeowner spent about $500, mostly for Dumpsters, and they will have to pay to have soil brought in.
Yet Steven Nutter, whose Maple Avenue yard was the larger work site, said he can’t wait to grow melons, okra, asparagus, corn, and heirloom tomatoes — and maybe put in a plum tree as well. He has been planting gardens since he was a child in West Virginia, and he would like to inspire others to do the same.
“I hope that more and more people de-pave their yards,’’ Nutter said. Several of the volunteers expressed similar wishes — and based on their mood after de-paving, it’s easy to imagine them jumping at the chance to do this again.
“It’s exhilarating just to physically be able to work like that,’’ said Koslow. “There’s a passion behind it when you know you’re breaking something up that doesn’t belong here, and that we’re putting back the earth the way it needs to be.’’