redesign the city: a look at urban permaculture
by Liz Neves
David Holmgren's Permaculture Flower
If we speak of a healthy community, we cannot be speaking of a community that is merely human. We are talking about a neighborhood of humans in a place, plus the place itself: its soil, its water, its air, and all the families and tribes of the nonhuman creatures that belong to it. What is more, it is only if this whole community is healthy…[and] the human economy is in practical harmony with the nature of the place, that its members can remain healthy and be healthy in body and mind and live in a sustainable manner. ~ Wendell Berry
According to permie.net:
Permaculture is the design practice of creating truly sustainable human settlements that mimic, honor, and cooperate with natural ecosystems.
A city is both an organism and an ecosystem. Its elements are intertwined and overlapping. Yet, most cities are dysfunctional in terms of operating like a healthy ecosystem or closed-loop system.
The way modern cities are set up, it takes many outside resources to keep them functioning. Our food is trucked in, our goods are trucked in (or flown or shipped in), our water is piped in from external reservoirs. And in turn, many resources we produce, mainly in terms of what we call “trash” or “pollution” are carted off or washed away with the rain. Our food scraps and material trash are sent to landfills way outside of the city. Our sewage is flushed to sea; rainwater flushes sewage and chemicals into the ocean.
This is the height of inefficiency and dysfunction. Why can’t we utilize the resources we have in our cities? Why are we throwing them away?
One easy answer is, it’s just the way it is. It’s how our cities have been set up and there are various barriers to change the way things are done. But I won’t get into the bureaucratic problems or political barriers. I’m here to talk about solutions to the tangible stuff. In many cases, one solution will handle many problems. And as permaculturists (aka, permies) like to say, The Problem Is The Solution. Here are some examples.
Problems #1:
- Toxic soil
- Poor air quality (non-compliance with the Clean Air Act)
- Greenhouse gas emissions (climate change)
- High populations suffering from asthma, obesity, diabetes
- Dependence on outside resources for food
- No place to bury waste (no landfill space)
- Rats
Solution #1: Composting & Food Production
Food scraps are perhaps the number one wasted resource of big cities. Composting food scraps (mixed with leaf litter, paper, tree trimmings and other carbon) will provide nutrient rich soil. Nutrient rich soil has the power to remediate toxic soil. Nutrient rich soil has the power to grow food.
If we don’t truck out our food scraps and instead remediate our soils and grow our own food then we’ll have eliminated the need to truck in food as well. Fewer trucks in and out means fewer emissions polluting the air, which means reduced asthma triggers. If we’re growing nutrient dense food in the city, our people will be eating healthier and reducing their risk for diabetes and obesity.
The Fort Mason Community Garden in San Francisco. Credit: Briggs Nisbet, The Architect's Newspaper
Food scraps, when put in a landfill, release the powerful greenhouse gas, methane. Methane is 25 times more potent than carbon. If we compost our food scraps and other wastes, there will not just be less to bury in a landfill, there will be a reduction in greenhouse gas emissions.
Oh yeah, the rats. If we’re not putting our food scraps on the curb and instead properly mixing them with carbon (trees, leaves, etc.) to create compost, we won’t be tempting our little four-legged friends with midnight curbside snacks.
Problems #2:
- Combined sewer overflow (CSO)
- Dependence on external water resources (reservoirs)
- Polluted waters (non-compliance with the Clean Water Act)
- Urban heat island effect
- Extreme energy demand in summer (air-conditioning)
- Thirsty street trees
- Nature deficit disorder
Solution #2: Hold onto the Rain
The urban environment – paved over, filled in, built upon. Concrete and asphalt are ubiquitous, and are not permeable surfaces. Water rolls off of them, picking up whatever particulates happen to be lying around – lead, mercury, petrochemicals, trash. This polluted water finds its way to the river, to the ocean.
The way our sewers were set up, combining raw sewage with stormwater run-off, well, you can imagine this toxic mire just floating into our waterways every time it rains. As little as 5/8 of an inch of rain is enough to set up a combined sewer overflow (CSO) event in New York City.
In this paved-over place, any semblance of plant life grows in the cracks and crevices in between hardscape, in abandoned lots or abandoned buildings. (A good example of this was the High Line, before it became a park.) This plant life has the power to hold onto the water and store it, preventing the stormwater run-off that pollutes the water.
If we let things be, natural succession of plant life will take place, albeit slowly. But if we speed succession, green will return, which will both keep rainwater on site and invite wildlife back.
There are several ways to approach this, a combination of which can solve the problem. Here are some impactful approaches to increasing water-absorbing potential:
- Plant and care for street trees (and give them bigger tree beds, where possible)
- Install and care for green roofs
- Create more rain gardens
- Start more and tend existing community gardens
- Break up parking lots and other underutilized hard surfaces to create riparian buffer zones
In planting more, gardening more, we will reduce the hardscape and increase the natural green landscape which in turn reduces urban heat island effect, stormwater run-off (and CSOs, polluted water), the need for excessive air conditioning. And we’ll also have the psychological benefits that greenery brings (Please see this wonderful document, Restorative Commons: Creating Health and Well-being Through Urban Landscapes for more on the subject).
Another way to hold the water in the city is through rainwater harvesting. There are some fairly simple systems for rainwater harvesting which can be used to water street trees, gardens, urban yards, and urban farms. In many places – such as Singapore, Japan, and Germany – rainwater is now being used for general residential use. Perhaps someday we will use rainwater to feed our showers and laundry machines in big modern cities as well, which would reduce our dependence on external reservoir systems.
Permaculture Links:
How would you like to see your city redesigned?
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