Update: See the Wall Street Journal write-up of this post.
Not many people move to New York for the yard space. Sure, my neighborhood in Brooklyn has a few little patios, some tiny backyards, two-foot wide strips of grass wedged between apartment buildings. But, as far as outdoor space goes, it all seems pretty unimpressive.
Until, that is, you begin to consider it collectively. In conjunction with CUNY, Evan Mason–a New York researcher who founded the organization Sustainable Yards–used geospatial imaging software to explore the city’s five boroughs. She found that, collectively, these tiny residential yards (and yard-like spaces) spaces comprise 26.82 percent of the city’s total area. (Yards do not include parks, sidewalks, or streets.) That’s an area equivalent to 62 Central Parks.
Now Mason is on to her next project—documenting the overlooked environmental benefits provided by these overlooked open spaces. She has spent her summer studying the residential yards on a single block in Harlem in an attempt to put a dollar amount on the ecological services these little spaces provide the city. I talked with her about her work.
What interested you about New York City’s yards?
Mason: It’s the confluence between historic preservation, urban planning, and the environment. The focus on existing buildings is always on the front of the building, the façade, what you see from the street. But there’s this whole vibrant community behind row houses. Once I started thinking about that, I went on Google Earth, and I looked at these spaces from above. You can see how many trees there are. It’s not just the rowhouses—it’s also apartment buildings. I just started thinking about what the environmental benefits of these spaces could be. I found that most of the literature that’s out there looks at public property and not residential property.
Mason: If you have looked at rowhouse backyards, you see how much life there is. There’s community back there. I’ve seen a hummingbird; there’s doves, there’s cardinals, there’s bluejays. Then there’s stormwater management. With these tremendous storms that we’re having, our water treatment system just can’t handle the bursts of rainwater. So the less concrete and the more soil that we have, the better for our water treatment system. There’s the urban heat island effect. Concrete absorbs heat, so the less concrete and more soil and vegetation again, the better.
So when it comes to wastewater management, it’s better for rainwater to seep into soil than to get funneled into the city’s water treatment system?
Mason: The more permeable the ground is, the better. Very simply said: Soil is good. It costs $127* a gallon to treat water in our water treatment system. So what we’ve done is actually gone into as many backyards as we can in one particular block. With CUNY, we’re actually measuring the square footage, how much is permeable, how much is impermeable. So if a whole set of backyards, is, say, 90 percent permeable, then you can start making a calculation of how many gallons are diverted from the water treatment system and how much money that saves the city.
Why haven’t these spaces been studied much before?
Mason: Public property is easier to study. It’s very hard to get access to these backyards. You can’t see them from the street, you can’t take pictures of them from the street. For us this summer, it was extremely difficult to get access—to locate people, to contact them, to get permission, to explain what we wanted to do. It’s labor intensive.
There needs to be more study. There’s a lot of attention, for instance, on green roofs, which are terrific. Green roofs are private property, just like yards, but it’s a whole lot more expensive. I think it’s much more unlikely that there’s going to be a huge number of green roofs installed, especially on existing buildings, over the next 50 years. The buildings weren’t constructed to hold that kind of weight. Even though I love green roofs–and it’s very sexy and cool and glitzy–my gut says that, especially in economically strapped times, it’s just a whole lot easier to bring soil in on the ground level than it is to bring it five or ten stories or more up.
You said that sprucing up a backyard is a lot like replacing incandescent bulbs with compact fluorescent ones. What did you mean?
Mason: It’s doable as a do-it-yourself project. You can do it on a micro level and just put a few plant containers, or you can go all the way and do water gardens and very extravagant surfaces and materials.
I think there are a lot of New Yorkers who want to be green. They might look at a small bit of open space in front of or behind their house and say, ‘Well what good could this do?’ But the more information we have about the environmental benefits of these spaces, the more we see that cumulatively, tremendous benefits can be realized. It’s a nice way of doing something for the environment that does something for you as well. Does it really make me feel good to recycle a can? No, not really. It doesn’t enhance my life. But if I can do something good for the environment and sit outside on a gorgeous day like today—even if it’s a little space—how great is that?
Note to New Yorkers: Mason is looking for photographs of backyards all over the city. If you’ve got one you’d like to share, e-mail it to email@example.com. She is also looking for more city blocks to assess. If you’d like to volunteer your block, send an e-mail to the same address.
*Correction: The initial figure Mason provided was incorrect. As soon as I get a revised figure, I will note that. Apologies for the error.