The website Better! Cities and Towns recently posted an article about what makes great city streets great. There are a lot of things at play in the examples they give from cities around the world, including multi-modal transportation, safe sidewalks, restaurants, and trees. I couldn’t help but notice that this was a common thread throughout all of the examples, and I was excited to see a portion of the article dedicated to the value of trees in urban areas and the effect they have on making city streets great. There was even a specific reference to green infrastructure benefits.
There are a ton of benefits that trees provide for our cities, neighborhoods, and homes that we can take for granted. Last week we mentioned that a large percentage of the monetary value provided by trees is by mitigating stormwater.
In the Gulf coast, the damage from both the drought and flooding are disrupting city and rural life as Ivan (now a Tropical Storm) passes. Although here in Washington State we don’t encounter hurricanes, all urban folk rely on cities to take care of water flowing through our soil and over our roads. Cities provided the infrastructure to collect, distribute, and treat stormwater and sewage at once, meaning that the pipes and tunnels can get overwhelmed when storms occur.
Here in King County, the Wastewater Treatment Division (WTD) is concerned about overflows that can occur when the system’s capacity is overwhelmed by stormwater. This causes environmental and health problems when overflows contain more than just stormwater, but also some sewage. The WTD’s project for Bioretention is one way the county takes advantage of the natural absorptive power of vegetation.
Trees are great at managing stormwater runoff from the leaves disrupting rainfall, to the roots system’s
storage of rainwater. According to the Alliance for Community Trees, mature trees can hold 50 to 100 gallons of water during large storms. Strategic tree planting can relieve pressure off of more traditional infrastructure – Detroit reduced overflow in 2010 by 10-20% in volume, saving about 159 million dollars a year. Trees are an effective, environmentally-friendly solution to an expensive problem.
Tree enthusiasts (hello!) know that urban trees are crucial for our communities – we feel it in our bones – but, how can we quantify this for our less enthusiastic neighbors?
A recent article in The Atlantic discusses “The Case for More Urban Trees” with a variety of new evidence for tree benefits. Programs in both the other Washington (D.C.) and San Diego County have cropped up, profiling the urban canopy. Interactive maps then allow users to view a summary of the benefits trees have for our community from carbon sequestration to water retention, energy conservation, and air pollution reduction. These tools put real numbers to the abstract benefits that city dwellers feel everyday.
In fact, these tools are not limited to specific counties in the country. The Casey Tree Foundation developed a Tree Benefit Calculator, where you can enter your location and tree species to discover the monetary benefit to your neighborhood or city. Intrigued, I looked up the benefits of the London Planetree right outside the Forterra office in downtown Seattle. At about 20 inches in diameter, our tree has $101 worth of benefits to the area mostly from the property value and stormwater mitigation. Trees have an extremely important and now more tangible value for our cities.
Even more incredibly, Seattle understands these benefits especially for city infrastructure like stormwater maintenance. The reLeaf program offers four FREE trees to city residents to keep the Emerald City green. Puns aside, city government is responding to the financial value of urban greenery that arborist research can pinpoint. Here at Green City Partnerships, we fully support this symbiotic relationship.
What makes a park work? Baltimore answered this question earlier this year with, “location, location, location”. City Planner Kevin Klinkenberg agrees. In his latest post on the benefits of walkable cities, Klinkenberg says what makes Forsyth Park great is how central it is (physically) to community life in the Savannah’s Historic District. Forsyth Park dominates the spine of the district for many blocks, squarely inserting green space into city living. It diverts traffic and allows pedestrians and cyclists a logical place to enjoy and congregate. Instead of making parks the land use of last resort, cities must to actively pursue locations for the best parks.
This is how purposeful city planning can develop urban forestry, and local communities! We are so excited here at Green Cities to have committed partners that bring the private and public stakeholders together to protect and restore urban green spaces just around your corner. And we’ll keep you in the loop as the benefits of urban parks are discovered around the nation!
Starting with a study of 1,000 random points in 20 large American cities, and comparing current digital images with images from 5 years ago, Nowak and Greenfield found “clear trends away from tree coverage and toward impervious coverage.” In 17 out of the 20 cities studies, tree coverage went down statistically. Impervious cover (roads, buildings, and other surfaces where water cannot be absorbed) rose in 16 of the cities. Our own Tacoma, Washington, had the largest increase in impervious surfaces in the entire study. To get an even more random sample of the whole country, they then selected 1,000 points in urban areas across the U.S. and compared those as well to come up with their estimate of an average net loss of 4 million trees from U.S. cities every year. What does this all mean? Fewer trees. More concrete. Lower air and water quality. Higher need for tree protection and environmental health programs in general.
Remaining end-of-season planting projects need all the helping hands they can get in the next month or two, so head to your nearest Green City and find a volunteer opportunity to get your hands dirty. As the days get longer and we start to think of drier weather (not that we’re complaining!), planting season is coming to an end. But, invasive weed removal and other projects going on in spring and summer help prepare the natural corners of our cities for more planting starting next fall. Hope to see you out there in Seattle, Tacoma, Kirkland, Redmond, or Kent. Let’s turn this trend around!
For years American urban parks fell into decay due to disinvestment, but as cities began to rebound—and evidence of the economic, cultural, and health benefits of parks grew— investment in urban parks swelled. The U.S. Conference of Mayors recently cited meeting the growing demand for parks and open space as one of the biggest challenges for urban leaders today. It is now widely agreed that the U.S. needs an ambitious and creative plan to increase urban parklands.
Urban Green explores new and innovative ways for “built out” cities to add much-needed parks. Peter Harnik first explores the question of why urban parkland is needed and then looks at ways to determine how much is possible and where park investment should go. When presenting the ideas and examples for parkland, he also recommends political practices that help create parks.
The book offers many practical solutions, from reusing the land under defunct factories to sharing schoolyards, from building trails on abandoned tracks to planting community gardens, from decking parks over highways to allowing more activities in cemeteries, from eliminating parking lots to uncovering buried streams, and more. No strategy alone is perfect, and each has its own set of realities. But collectively they suggest a path toward making modern cities more beautiful, more sociable, more fun, more ecologically sound, and more successful.