"Philadelphia has the first and only EPA-approved green infrastructure plan," said Mark Focht, FASLA, first deputy commissioner, Philadelphia Parks & Recreation and ASLA President, at the Dupont Summit, a meeting of the Policy Studies Organization in Washington, D.C. He said Philadelphia even needs to "train the EPA on how to evaluate our plan," which provides a cutting-edge, low-cost approach for dealing with his city's stormwater run-off problems.

A grey infrastructure system was estimated to cost more than $6 billion. The green infrastructure plan Philly is moving forward with will only cost $1.2 billion over 25 years. Some $800 million of that will go directly to green infrastructure projects in the city, while $200 million will go to further strengthening the city's water treatment plants. Another $200 is reserved for "adaptive management," which will address "future technological changes." Focht said even if future mayors tried to undo this 25-year plan, they can't. The agreement, which he emphasized is "not a consent decree," has been signed.

Green infrastructure provides many benefits beyond cost savings. There's a "triple bottom line effect," with multiple environmental, social, and economic benefits. On environmental benefits side alone, the potential payoff is massive. Focht said the greening plan could absorb or help the city avoid  some 1.5 billion pounds of carbon dioxide annually, which is equal to removing 3,400 cars off the road. "This number will compound each year." With improved air quality due to all the new trees, green roofs, and parks, communities will benefit on the social or health side, as well. Focht estimated 20 deaths due to asthma will be avoided, and 250 fewer work or school days will be missed. Deaths due to excessive urban heat could also be cut by 250 over 20 years. Lastly, the economic benefits also outstanding: the new greenery will increase property values by $390 million over 45 years, also boosting the property taxes the city takes in. In the short term, all those green roofs and parks need to be constructed, creating 250 local green jobs.

Focht said in contrast to grey infrastructure, green infrastructure creates a wider range of jobs, with more opportunities for convicts reentering society. "Grey infrastructure really just employs engineers." He added that green infrastructure benefits are immediate across all levels, while grey infrastructure has a "different curve" to kick-in and starting paying back.

Philadelphia's new plan is based on the "greened acre." According to Focht, "one greened acre is equivalent to one inch of managed stormwater from one acre of impervious drainage area, or 27,158 gallons of stormwater." There's even a formula: GA = IC * Wd. The city decided to come up with the greened acre concept to help communicate with the public about their goals over the coming decades. Over the next 25 years, Philadelphia wants to convert 9,600 impervious acres into permeable greened ones. That means 34 percent of the city's now impervious surface (or 15 square miles) will become permeable.  Greened acres can include rain gardens, trees, green roofs, permeable pavements, and green "bump-outs."

To implement this bold vision, the Philadelphia water department has steered city investment in city-owned properties in a greener direction and set the standards for all new construction projects. There's a green streets design manual that shows how permeable pavements should function. Focht said one street just put in had no drains. The water simply drains down into the permeable asphalt and the earth.

Strong new regulations will also move the private sector to act. "Water bills are now based on how much water you use and manage." One site with huge amounts of paved areas saw their water bill shoot up from $400 a month to more than $2,500, while another with no paved surfaces saw their bill go from $4,700 to $100. Focht made a point of saying that "the new regulations are not a revenue generator." But there are clearly winners and losers. "Losers include big box retailers, retail malls, and car dealerships."

Focht said if smart, a building like a condo could put on a green roof and get its water bill to zero. To push buildings to go this route, the city is offering a range of grants and loans modeled after NYC's program. "If a project increases the visibility of green infrastructure, it also gets more credits."

For the parks department, the new green infrastructure plan is a bonanza, creating opportunities for lots of new multi-functional green spaces. The parks department is already racing ahead: One new playground is 92 percent permeable, with new permeable pavements and plants. As a big plus, Focht said the neighbors love the pavement because it also absorbs the sound of basketballs bouncing. Green schools are coming, and there's even a green homes program that provides small grants to volunteer, non-profit groups to teach homeowners how to capture their own runoff.

One exciting project, deemed the "big green project," shows how these green infrastructure tactics can coalesce into larger systems. The new Kensington Creative + Performing Arts High School, which is LEED Platinum, has green roofs, rainwater cisterns, and an underground detention facility. Surrounding it is a newly permeable sports area, a "geothermal well field," and tree trenches.

So how did Philadephia make this happen, forming a partnership among so many different city agencies when so many other cities have failed to accomplish this? Focht said a "strong mayor" was central, as well as "city-wide planning framework that enabled real partnerships." Focht also mentioned how many people leading agencies now came up together through the ranks. When he and others were all middle managers at agencies, they formed an extra-curricular working group to discover how they could collaborative on green space, water management, and public health. Those efforts eventually bubbled up into Philadelphia's 2009 GreenWorks plan.

Importantly, Focht said green infrastructure initiatives have retained public support to date because city officials have made a point of making "the same investment in every neighborhood," rich or poor.

To learn more, download Focht's full presentation (7MB) and also read a report ASLA co-wrote with a number of organizations, Banking on Green: How Green Infrastructure Saves Municipalities Money and Provides Economic Benefits Community-wide.

Image credits: (1-2)  7th and Washington / Philadephia Parks & Recreation, (3) Expanded tree pit / Philadelphia Water department, (4) Kensington High School / Paul Rider