Portland’s Green Streets

25 11 2009

Streetsblog San Francisco had a great post last week that reported on a recent tour of Portland’s Green Streets taken during the Congress for the New Urbanism’s Project for Transportation Reform Conference. The post includes a number of wonderful green street examples. The quality of the installations are impressive. A representative of Portland’s Bureau of Environmental Services (BES) was quoted as saying the green streets were necessitated as a result of the City’s need to comply with a Clean Water Act lawsuit. The cost of conventional stormwater infrastructure topped nearly $150 million. This cost encouraged the city to explore alternatives like green streets for reducing water volumes. David Elkin,the BES representative quoted in the post, estimates the solution saved the City $60 million dollars in stormwater pipe replacement. The post is worth checking out.

-Brian Phelps


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Categories : Green Street, Streetscape, Sustainable Site Strategies

Triple Bottom Line of Green Infrastructure

18 11 2009

Before and After of Green Infrastructure Improvements
(Source:“Green Cities Clean Waters” Plan)

In an earlier post titled “Making Green Infrastructure Common Place” we discussed the recent release of Philadelphia’s $1.6 billion dollar “Green Cities Clean Waters” Plan. Its thrust is to transform over 4,000 acres of impervious areas within the City’s Combined Sewer System to green space over the next 20 years through the use of green infrastructure strategies. This would involve converting over 34% of all existing impervious areas. Of this, the conversion will primarily be made on public property and right-of-ways. Green streets, the most widely used management tool, will comprise nearly 38% of these improvements (see graphic). The report claims this is “the largest green stormwater infrastructure program ever envisioned in this country”. While green infrastructure has been utilized and proven in many parts of the country, the sheer magnitude and commitment of the city is a radical departure from the conventional approach to stormwater management practices.

Map of Green Street Locations
(Source:“Green Cities Clean Waters” Plan)

So why did Philadelphia decide to rely so heavily on green infrastructure as a means of reducing overflows in their CSO system? Quite simply it was cheaper, significantly cheaper. The plan estimates over the next 20 years the plan is to be implemented, the “triple bottom line” benefits (social, environments, economic) of the plan alone will add up to a present value of $2.2 billion dollars. The following is a breakdown of the benefits that comprise this figure.

  • Heat Stress Mortality Reduction (35%)
  • Recreation (22%)
  • Property Value Added (18%)
  • Water Quality and Habitat (14.5%)
  • Air Quality (4.6%)
  • Avoided Social Costs from Green Jobs (3.7%)
  • Energy Savings (1.0%)
  • Carbon Footprint Reduction (0.6%)
  • Reduction in Construction- Related Disruptions (0.2%)

So instead of employing conventional underground infrastructure that is one-dimensional, and is estimated to cost $16 billion, the city has decided that implementing a multi-dimensional strategy with multiple benefits made more sense. But not only is it more desirable, it is politically easier to implement because it makes the city a more beautiful and healthy place. So if you are going to have to spend the money anyway, why not make it count.

The shortcomings of the conventional “tanks and tunnels” approach were not only that it exceeded the EPA’s affordability standard for stormwater management (2% of median household income), but it also did not address water quality issues and could require green infrastructure tools anyway to meet these requirements. In addition, the report points out that the conventional solution isn’t aligned with the EPA’s broader goals of sustainability, reduces streams baseflow thereby damaging the resources that is designed to protect, and doesn’t offer any secondary triple bottom line benefits. Furthermore, since the conventional solution is not delivered incrementally it is not flexible and does not offer any benefits immediately.

Green infrastructure on the other hand offered the city the opportunity to revitalize and restore the city’s streams and rivers, enhance the quality of the built environment throughout the city, improve air quality, reduce the heat island effect, and sequester carbon. While accumulating these benefits, the approach was more flexible, offered immediate benefits, and, most importantly, the cost of implementation was offset by the dollar value of the benefits. (see Volume 2: Triple Bottom Line Analysis of the plan for specifics)

While conventional infrastructure has its place, the combination of the two can play a significant role in addressing many of the issues facing our cities. It is critical that we continue to move toward making these strategies common place. By doing so we can make our cities healthier and more beautiful for all of us to enjoy, while at the same time responsibly managing our stormwater.

-Brian Phelps


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Categories : Bioretention, Green roof, Green Street, Pervious Pavement, Sustainable Site Strategies

Chicago Green Roofs: Seven Million Square Feet and Growing

13 11 2009

green_roof_sedum

I got the chance to spend a little bit of time last week with Chicago’s firecracker Commissioner of Environment, Suzanne Malec-McKenna while she was in Nashville for the Nashville Civic Design Centers annual Plan of Nashville event. Suzanne has been in the middle of an astonishing number of Chicago’s environmental bright spots, including the ambitious Chicago Climate Action Plan released in 2008, Chicago Trees Initiative and the very cool Chicago Offset Fund. But what has impressed me the most (and has for a long time) is Chicago’s tremendous growth in green roofs.

It all started in 2001 with the now well-known Chicago City Hall roof weighing in at a modest 20,000 s.f. In June 2008, a short seven years later, Chicago boasted 4,000,000 s.f. of green roof and today, they report that they have hit 7 million s.f. and they are still going. I wanted to find out more about how such an explosion occurs and one of the pieces and parts is related to the success of the green roofs is a Green Roof Grant Program begun in 2005 which has been continued and expanded. An interesting side note is that the popularity and volume of the green roofs across Chicago has also reduced the average installation price of extensive green roof in Chicago has dropped from $25/s.f. to $15/s.f.

As if the incentives of grant incentives aren’t enough, I also noticed that in August 2009, the Illinois Energy Plan provides ARRA funds toward cost-effective energy projects, including green roofs, which meet certain criteria. Illinois has recognized that green roofs provide economic development, carbon capture and energy and maintenance cost savings.

As I looked around at other cities, I found a few more that were engaged in similar incentive programs introduced within the last year: Portland, New York City and Washington DC (List of green roof incentive programs) . Through tax abatement or grants, each of these cities provide an incentive of about $5.00 per square foot through a green roof review process. Portland expects their Grey to Green Program to their current nine acres of green roofs on about 90 buildings to increase over the next five years by another 43 acres. Portland is committing $300,000 in grants in its first fiscal year of the program and is committed to keeping the program going for at least the next five years.

In our neighbor to the north, Toronto started the green roof incentives in 2006 starting with a $10 per square meter subsidy, then raised the subsidy amount to $50 per square meter in order to be more effective. Reports are that funding of $2.4 million dollars for green roof subsidies have been approved for the first five years of the program.

So hats off, Chicago! You are serving as a great example for the rest of North America – in fact, Chicago topped the Green Roofs for Healthy Cities list of top ten cities for both the United States and North America for the past five years.

-Kim Hawkins


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EPA to test porous pavement and raingarden benefits

11 11 2009

1700 Charlotte
1700 Charlotte in Nashville
Combines Porous Concrete & Bioswales

Traditional asphalt parking lots may seem to be the most cost efficient, but underlying costs such as increased pollution and water load on our sewer systems need to be considered as well. In an attempt to measure those underlying costs the EPA has replaced nearly 43,000 SF of their traditional asphalt parking with 3 different types of permeable pavement systems and several raingardens with different planted vegetation. At their Edison, NJ facility they will conduct a decade long study to evaluate and document the performances of these permeable systems on the basis of removing pollutants and filtering capabilities. Having these systems all in the same location will likely result in more balanced testing of each material.

This study comes at an ideal time as many cities are beginning to re-evaluate old paving methods in order to reduce the load on existing sewer systems or just to reduce the amount of toxin runoff from paved surfaces to our nearby rivers and lakes. Traditional asphalt parking lots collect oil, grease and other debris over time, after a heavy rain or snowstorm these toxins are washed from the parking surface to the nearest storm drain or permeable surface. Replacing this impervious surface with a permeable pavement or raingarden will allow plants and soils to naturally filter the pollutants, while re-charging the ground water table.

Porous for Blog
Porous Concrete

-Will Marth


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Categories : Bioretention, Pervious Pavement, Sustainable Site Strategies

Making Green Infrastructure Common Place

6 11 2009

Philly_Green_City1

Getting more for less is an approach almost everyone can appreciate. Why wouldn’t you want to get the most out of your investments? Appropriately applying green infrastructure in ways that effectively addresses critical stormwater issues while creating a more beautiful and economically vibrant community is common sense. Unfortunately, it isn’t common place. As the use of the available sustainable site tools and technologies continues to grow, it may not be long before green infrastructure is the conventional approach to stormwater management.

With the Release of their “Green Cities Clean Waters Plan”, Philadelphia joins a handful of cities across the Country that have committed to green infrastructure and seek to institutionalizing it throughout the city. Philadelphia’s plan published last September sets forth a bold plan to invest $1.6 billion. Of this total 62% ($1 billion) of it will allocated directly to green stormwater infrastructure. Another 18% ($290M) will directed to stream corridor restoration and preservation and 20%($320M) will address wet weather treatment plant upgrades.

Over the next few weeks we will take a closer look at Philadelphia’s plan. At over 3,000 pages, there is a lot of information to sift through. In addition, we will also look at Pennsylvania Environmental Council released a report titled “Implementing Green Infrastructure: Developing a Winning Strategy to Fund Philadelphia’s Ambitious Plan” that looks at the economic benefits of the plan and how other cities across the country are funding their stormwater initiatives. Together they are an impressive step forward for the City of Philadelphia and the Nation.

-Brian Phelps


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Categories : Plans and studies, Sustainable Site Strategies, Uncategorized

Deaderick Street’s Transformation

28 10 2009

The Tennessee Urban Forestry conference was in town recently and asked Hawkins Partners to give a guided tour of the Nashville Public Square and Deaderick Street. This marked our first “official” tour of Deaderick Street to discuss all of the exciting new aspects of the green street.

Deaderick_Street_3

The recent transformation of Deaderick Street recalls the historic importance of the street and enhance the corridor’s prominence as an important civic axis. Prior to the renovations, the street had become most widely known as the central transfer point for the Metro bus system. In the Fall of 2008 the bus system’s hub was relocated one block over to the ambitious Music City Central, presenting an opportunity to re-envision the street itself

Deaderick_Street_4

The renovations to the street primarily focused on addressing stormwater issues and urban trees. The existing streetscape was home to an assortment of unhealthy trees ranging in sizes from 2” caliper up to 24”+. Each and every one of them were shoehorned into a 4’x4’ planting zone and struggling to adapt to urban conditions. The renovations included removing those trees and providing larger and deeper planting areas that would not only give a larger volume of soil for the tree roots, but also provide many areas in which the stormwater could travel to, thus reducing the loads into the storm system. Bioretention zones were implemented in pedestrian bulbs at the intersections and in relation to the existing catch basins. These planting areas were also excavated to a depth that would accept enough engineered soils to allow infiltration and planted with plants that can adapt to the extremes of wet and dry conditions. Pervious area within the corridor was increased by over 700%.

Deaderick_Street_1

Many other elements of sustainability were included, such as:

  • Crushed and recycled concrete used for the pavement subbase,
  • Fly ash utilized in the concrete mix,
  • Porous concrete,
  • LED light fixtures,
  • Native and drought tolerant plant materials,
  • Solar powered parking meters,
  • Water efficient irrigation system,
  • Many local vendors and fabricators,
  • The addition of bike racks to help encourage a healthier way to travel, and
  • The addition of recycling receptacles along the street.

We’re hoping that in the near future, permanent retail kiosks that were proposed in the master plan will be added to the street, further enlivening the corridor. Those kiosks are proposed to have an extensive greenroof on each. In addition, the master plan identified areas for future free standing retail buildings and liner buildings that could be added on the blank facades.

– Laura Schroeder


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Categories : Green Street, Pervious Pavement, Public Space, Streetscape, Uncategorized, Urban Planning & Design, Water Harvesting

What SHOULD be green about our city’s infrastructure?

19 10 2009

green_infrastructure

Green. These days that one word has many different meanings. Growing up, I could count on “green” being one of the eight colors in a Crayola package, but today, this one word has many more connotations. Being landscape architects, we plan to use this blog as a way to explore “green” in terms of site sustainability issues, with a focus on green infrastructure. So maybe we start with the first question: What SHOULD be green about our city’s infrastructure?

When we think about stormwater infrastructure, it is generally conceived of as the complex system that accepts, stores, manages and treats our stormwater. In the conventional designs of the past several decades, this has been done through drains, pipes, curb and gutter and a whole host of devices to hold or detain the water from our bigger storms. With green infrastructure, we look at the potentials of natural systems to deal with those same issues: more interception of stormwater allowing it to evapo-transpire, infiltrate and be held and used for others purposes (like irrigation or flushing water for toilets). This reduces the load on our aging storm pipe system, allowing it to function longer AND it often allows a more cost-efficient solution for the life of the project.

Specifically here at Green Infrastructure Digest we’ll discuss green infrastructure as it relates to four primary areas:

  • buildings and structures/ green roofs and green walls
  • hardscape / pervious pavements and overflow inlets
  • landscape / bio-swales, raingardens, green streets
  • water capture and reuse / rainwater harvesting, greywater harvesting, passive irrigation
  • related site sustainability issues

Over the past 23 years at our firm, Hawkins Partners, Inc. landscape architects, we have had the opportunity to put this talk into practice having now designed over 500,000 s.f. of green roof, being involved in the first three LEED projects in the State of Tennessee (and many more since then) and incorporating many of these sustainable practices effectively in a number of different projects. We find that our clients like the idea of getting back to natural systems and putting dollars into aesthetically pleasing solutions that also deliver an environmentally sound and cost-conscious solution.


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