Philadelphia Green Infrastructure Video

7 09 2010

I recently came across this video covering Philadelphia’s Green Infrastructure Efforts. It was created by GreenTreks, an award-winning Philadelphia-based non profit communications organization dedicated to educating people about the interconnectedness of environmental, societal, economic, and individual health. For more information and links to other resources on Philadelphia’s triple bottom line green infrastructure strategy  see our past post  Triple Bottom Line of Green Infrastructure.

Brian Phelps





Deaderick Street Discussed at StormCon 2010

20 08 2010

Kim Hawkins, a principal with our office, recently spoke at this years StormCon in San Antonio, TX. She and Jim Snyder P.E., who at the time of the design and construction of the street was with Metro Nashville Public Works and who is now with Metro Nashville Water Services , spoke about the process of bring Nashville’s 1st Green Street to fruition. The following is the abstract about the presentation.

ABSTRACT: DEADERICK STREET – TENNESSEE’S 1ST GREEN STREET

Nashville, TN

Nashville Metro Public Works, Client

Hawkins Partners, Inc worked with the Office of the Mayor and Metro Public Works to transform a historically and civically significant corridor in the downtown area which serves as a physical connector between the city/county courthouse and the state legislative arm of government. 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 north to the ambitious Music City Central, presenting an opportunity to re-envision the street itself.

Deaderick Street sits within the Kerrigan Basin, one of Nashville’s Combined Storm Sewer (CSS) basins, that has historically been subject to overflows., it is Nashville’s first implementation of LID features in the public right-of-way, the first green street in Tennessee and one of the first green street applications in the southeast. The renovations to the street primarily focused on addressing stormwater issues and urban trees.  Pervious surface within the right of way was increased by 700% through the use of rain gardens, pervious concrete and .bioswales were implemented in pedestrian bulbs at the intersections.  The site design worked within the context of the existing street and the existing storm drainage system, retrofitting existing storm drains to serve as overflow only. Rain gardens and bioswales were designed with engineered soils to allow infiltration and planted with plants, including many natives, that are adaptable to the extremes of wet and dry conditions. Based on Nashville’s historical rainfall patterns, infiltration rates and variable design factors, it is estimated that over 1.2 million gallons will be removed from the CSO system on an annual basis through this three block urban street..

In addition to the stormwater aspects of Deaderick, a number of other sustainable features were incorporated into the street, including LED lighting, recycled steel site furniture, crushed concrete as base aggregate material, fly ash for concrete and solar powered parking meters.





Density as a Best Management Practice (BMP)

4 06 2010

High Point Neighborhood mentioned in Ped Shed Post
photo credit: sitephocus.com

The Ped Shed, a blog focused on walkable urban design and sustainable placemaking by Laurence “L.J.” Aurbach, recently had a post about density as a best management practice (BMP). The post provides a good outline of the evolution of the stormwater regulatory environment. The main point of the post is that well intentioned stormwater regulations make it difficult to build dense walkable environments that ultimately exacerbate stormwater management issues.

The author states:

“But the universal and inflexible application of BMPs and LID can have significantly negative consequences on the quality of urban places and the health of watersheds. LID purports to encourage smart growth and urban redevelopment, but as a rule this support is nominal, little more than lip service. In general practice, LID puts urban density at a competitive disadvantage.”

He cites three studies, two by the EPA (Protecting Water Resources with Higher-Density Development, Using Smart Growth Techniques as Stormwater Best Management Practices) and one by Jacob and Lopez (Is Denser Greener? An evaluation of higher density development as an urban stormwater quality best management practice.) All of them provide compelling data as to the benefits of density with regard to stormwater run-off and pollutant loads, and are well worth reading.

I agree with him that when developing an urban vs suburban site, more expensive stormwater BMPs are typically utilized (i.e. underground detention, green roofs) to meet stormwater regulations.

However, site area, property costs, and market dynamics are a large factor in determining appropriate BMPs and cost effective solutions. If you can build significantly more square footage due to a better market environment and/or need to maximize your investment in land cost (which often reflects the market potential and property entitlements) then the cost of best management practices that maximize these potentials can be offset.

The examples of offsite mitigation are very intriguing. I wholeheartly agree that opportunities for this on properties in close proximity to the development is an effective way to mitigate stormwater impacts while spreading (and hopefuly lowering) the cost across multiple properties. In regard to infill developement, this can be very difficult in practices but not impossible. Public space can be designed to accommodate the needs of neighboring properties. Using green roofs, pervious pavements, and other BMPs on surrounding properties can greatly reduce the volume of runoff being diverted to these offsite areas and therefore their size  can be diminished to a point that can be integrated better into urban environments.

-Brian Phelps





Ecological Importance of Southeastern Rivers

10 03 2010

Interpretive signs for an upcoming project near the Harpeth River in Williamson County will highlight the ecological significance of the waters of the southeastern United States. If you didn’t know, the rivers and streams of middle Tennessee are part of the most unique and diverse freshwater ecosystem in the entire world. This has to do with a couple things, namely the temperate climate combined with the fact that much of the area was unglaciated, or it as been more geologically stable than other parts of the U.S.

Just to give you an idea the area is home to more than 250 species of crayfish (70% of all the species in the entire U.S.), more than 300 species of mussels (over 1/3 of these live in Tennessee), and more than half the freshwater fish species in the U.S. Because of this great diversity, Tennessee has more freshwater fish that are at-risk than any other state. These species are at-risk largely due to pressures from development practices, which allow sediments and pollutants to wash into our rivers and streams. This and other topics concerning protection of critical watersheds can be found in, Rivers of Life or States of the Union: Ranking America’s Biodiversity, just some of the publications found on the NatureServe’s website.

Graphic from 'Rivers of Life', published by NatureServe

As mentioned in an earlier post, the implementation of ‘green street’ practices on Deaderick Street in downtown Nashville will divert approximately 1.2 million gallons of stormwater a year from the Cumberland River. This is water that would have otherwise run unabated into the river carrying all of the pollutants and sediments from the street. Understanding the significance of the region’s biodiversity is a good reminder of what we are trying to protect when implementing green infrastructure planning and strategies –and why this is especially important here in the Southeast and Middle Tennessee.

-Sara Putney





Water and the Southeast False Creek Olympic Village

22 02 2010

Cover of Water + Building Landscape (Chapter 6)
from The Challenge Series Website

Staying with the Olympic theme from last week’s post on the Vancouver Convention Centre, the Southeast False Creek Olympic Village is another spectacular example of sustainable building in Vancouver. The Olympic Village will house the athletes throughout the games. Afterward, it will become the home of over 16,000 residents. The following is a link to the diversity of uses that will be or are already included in the development.

A website called “The Challenge Series” has been set up to help educate the public about the Olympic Village’s sustainable features. A well-designed booklet describing the sustainable features of the development is available on the site in pdf format. One that particularly caught my attention was the Water + Building Landscape section (See Cover Above). It explains many sustainable water strategies employed throughout. Some highlights include:

  • The design team recognized the size was not large enough to handle all of the stormwater in the constructed wetland incorporated into Hinge Park. As a result, the team prioritized the water into a two-tier system. The first tier was considered the “cleaner” water that came from the rooftops and podium sections of the building. This water was directed to the cisterns in the basements of each building. The water was then used to flush toilets, supply water features, or irrigate the landscape. Additional water overflowed the cisterns and entered the South False Creek. The second tier included “dirtier” water. This water came from the roadways and other areas. The water from these areas was directed into the constructed wetland or underground gravel/sand infiltration cells.
  • The development reduced potable water use by 40 percent.
  • The site plan incorporates a number of water features that utilize the water collected on the site. The circulation through the water features provides a means of making what would otherwise be invisible visible, while at the same time improving the quality of the water.
  • 287,000 s.f. of green roof covers the development. The roofs include both extensive and intensive green roofs. This was in part because the City of Vancouver mandated that 50% of the roofs be green roofs.
  • The City also mandated the inclusion of urban agriculture at a rate of 24sf for 30% of the units whose balconies were less than 100sf.

The development has received LEED-ND Platinum certification. I look forward to seeing it one day when I return to Vancouver. There have been a number of articles on the development, but I highly recommend reading the information found on The Challenge Series website.

-Brian Phelps





Interview with Portland BES Part 1 of 3

3 02 2010

Portland Building (Location of Portland BES Offices)
Source: City of Portland, Environmental Services ©2009

The following is the first part of an email interview I recently conducted with Emily Hauth, project manager with Portland Bureau of Environmental Services (BES)’s Sustainable Stormwater Management Division. Their agency has been a leader in sustainable stormwater implmentation over the last twenty years.

Green Infrastructure Digest (GrID): The City of Portland has been and continues to be a leader in implementing green infrastructure facilities. Please tell our readers a little bit about the work the Bureau of Environmental Services (BES) is doing in regard to increasing the use of green infrastructure. What new innovations should we expect to see out of BES in the coming years?

Ms. Emily Hauth: Our sustainable stormwater management solutions have evolved from a single purpose regulatory driven approach to one that achieves multiple objectives. We are designing our urban landscapes and street systems with an eye toward community enhancement, cooling of the air and water, increased wildlife habitat and greenspace, safe bike and pedestrian linkages, greenway connections to services and amenities, and of course capturing and treating stormwater at the source on the surface. In this way we are achieving watershed health goals and meeting regulatory compliance while informing a new approach to urban development.

We are incorporating green infrastructure approaches into our policy development and planning processes. We have a number of policy initiatives that recognize green infrastructure solutions as a smart way to plan for watershed health and the city’s future and direct city bureaus and agencies to cooperatively plan and implement green infrastructure elements as part of all work programs. Our bureau works collaboratively with other City bureaus and agencies such as our Bureau Of Transportation and the Portland Development Commission on projects that promote environmental concepts while addressing auto, pedestrian, and bicycle safety. We are also fully integrating our watershed health and stormwater/sanitary collection goals into our Systems planning process. Portland’s Grey to Green initiative, established in 2007, sets a 5-year goal to increase green infrastructure elements throughout Portland including 900 Green Streets, 43 acres of Ecoroofs, and over 50,000 new trees.

In one particular area of the city where pipes are failing or undersized, we are incorporating green street facilities into the solutions plan. This area is referred to as Tabor to the River. In this area alone, we will be constructing 500 green streets. We’re also working closely with targeted private property owners to help them manage stormwater on their sites and play a role in the solution. All future work to address similar issues will follow this model of combining grey and green infrastructure solutions.

We don’t feel we have all the answers so we continue to ask ourselves, is it working? We continue to monitor our facilities, modify designs, research components such as plants and soils, to refine our knowledge base and maximize facility function and performance. We’re always looking for efficiencies in design and construction so we’re evaluating use of modular or prefabricated components for sustainable stormwater solutions. Other innovations we’re exploring include using a curbless green street design, new design options that manage both public and private runoff, and green walls that manage stormwater. We’re also developing a volunteer green street maintenance program that engages the community while helping the city meet its maintenance needs.

Planter at Mississippi Commons
Source: City of Portland, Environmental Services ©2009

Part 2-On Friday

-Brian Phelps





Trees and Their Impact on Economic Development

1 02 2010

Hill Center Green Hills, Nashville, TN

A discussion was started on the ASLA LinkedIn group last week regarding street trees’ impact on retail districts. The discussion centered on Professor Kathleen Wolf’’s research. Professor Wolf is a Research Social Scientist in the University of Washington’s College of Forest Resources Department. She has been at the forefront of the research being conducted in this area. Like the landscape architect who started the conversation, I have also been wondering if anyone has taken her research a step further. Professor Wolf’s research relies on user surveys that include both visual preference surveys and traditional questionnaires that ask respondents to rate environments and/or their willingness to pay more for a product.

In an Arborist News article published last year, Dr. Wolf reported on the work she has been doing. In the article, she reports that across all categories, places rated steadily higher with the increased presence of trees. Larger trees rated higher than smaller trees. Her surveys that looked at product pricing within districts with trees indicated that customers are willing to pay 9 percent more in smaller cities and 12 percent more in larger cities.

In her response to an emailed question posted on LinkedIn, she explains that she does not suggest that trees are the panacea for other business challenges and that there is not a simple casual link between having trees and increased revenues. Street trees and streetscapes are positive reinforcement of the “atmospherics” that market researchers consider to have influence on consumer’s buying habits.

I agree that street trees and streetscapes do add a considerable amount to the ambiance and character of place that people enjoy. Anecdotally, I think most people can understand the impact trees have on how we feel in a space/district. However, since retail success can be very sensitive to location and surrounding demographics, it can be difficult to make a clear connection between retail sales and trees. I hope that research continues to make the case, and like the sophisticated interior research done by market researchers, we can continue to increase our understanding of this relationship.

The article in Arborist News also offered some guidelines on street trees in retail districts such as the proper tree species, size, maintenance, and providing signage that contrasts with the trees’ foliage. I would add that tree placement along the street and their relationships to the doors, windows, and dividing walls between businesses are also important to consider.

The reports on Professor Wolf’s website Human Dimensions of Urban Forestry and Urban Greening are worth checking out.

-Brian Phelps





Updated Tree Carbon Calculator

18 01 2010

I know as landscape architects it seems like we are always talking about trees, but there are just too many good reasons not to, especially in urban scenarios. On our Deaderick “green street” project we made the focus of one of our environmental education signs on the importance of urban trees. The Center for Urban Forest Research, run by the US Forest Service provided a wealth of facts and resources for us to include on the Deaderick Street sign.

One of the Signs from Deaderick Street

Recently, the Forest Service has updated their Tree Carbon Calculator so that it works nationally instead of just for California. You can find the updated version in their Climate Change Resource Center. The calculator runs off an excel platform and allows you to input data for a single tree. Based on your region, tree species, distance for the building, and a number of other factors it will give a basic idea of how much annual energy, emissions and stored carbon you can expect. I used it to see the effects for a couple of trees I have outside my house. Even a small 6” tree has the potential to sequester over 65lbs of carbon dioxide from the atmosphere per year and that big 30” oak tree in my back yard, over 1000lbs per year, not to mention all the energy reductions too.

This is another useful tool to help prove the value trees. It is projected that over the next 50 years climate change will actually cause the southeast region to become warmer and drier, which would reduce the amount of forest growth. While the best option for managing this in the future is to keep forest as forest (per a publication from the US Forest Service titled ‘Forest and Carbon Storage‘), it can’t hurt by incorporating as much urban tree growth into new developments as possible, every little bit makes a difference.

-Sara Putney





Getting More: Multi-Functioning Facilities

13 01 2010

When it comes to adding more park space, communities are increasingly looking at getting more bang for their buck. Budgets are tight and cities are having to pool their resources from a variety of sources to get projects built. Two recent projects, one that is under construction in Los Angeles and another just announced in New York City, seek to create a park and nature area for their citizens while also constructing wetlands to address stormwater management issues within the immediate neighborhood and the community at-large.

The first is the South Los Angeles Wetland Park. The 9-acre park under construction five miles south of downtown Los Angeles on a former transit maintenance facility that is nearly 100% paved. The City recognized that more recreational open space was needed in the area while also needing to improve the quality of the stormwater runoff that ultimately was polluting the city’s beaches. The park transforms the site into a extensive wetland that comprises most of the park. It includes a series of trails, an observation area, and public gathering areas.

The park is estimated to cost $24 million. The funding was cobbled together from a variety of sources, including money generated from Proposition O. Proposition O passes in 2004, authorized the city to issue up to $500 million in bonds for cleaning up polluted storm water and bacteria in the City’s rivers, lakes, beaches and ocean. Stormwater Magazine has a thorough article about the genesis of the park and its design. Also, more detailed information can be found on Proposition O’s website.

South Los Angeles Wetland Park Site Prior to Construction
Source: Google Map

South Los Angeles Wetland Park Site Plan
Source: Proposition O Website

The second improvement is the Paerdegat Basin Restoration Project in New York City. The Department of Environmental Protection recently announced the $15 million project. It is anticipated to be completed by 2012. The park will restore 38 acres of wetlands and natural grassland areas adjacent to the $357 million Paerdegat Basin Combined Sewer Overflow (CSO) abatement project. Five acres will be dedicated as a Ecology Park that will be accessible by the public and offer educational opportunities. Funding for the project is provided by Clean Water State Revolving Funds. The combined projects are designed to store 50 million gallons of CSO during a storm event. (Press Release fro DEP)

Both of these projects serve as examples of how various communities’ goals can be combined and met by a single green infrastructure investment. As cities approach future planning and implementation efforts, they should look beyond the immediate objectives of the project and assess how the project might serve to address other needs that have been identified in the community.

-Brian Phelps





Sustainability Resource Guides from ASLA

14 12 2009

The website for ASLA (American Society of Landscape Architects) has a fairly new section devoted to resources for sustainable design and planning. If you haven’t wandered across it already you should take a minute to see what it has to offer. It is aimed at national and local policymakers, government agencies, design professionals, planners and students. Resources include hundreds of project case studies, research papers, organizations and other government resources on sustainable design.

The following description of the five resource categories is taken from an announcement by ASLA, they include:

  • Green Infrastructure (www.asla.org/greeninfrastructure) covers park systems, wildlife habitat and corridors, urban forestry and green roofs.
  • Sustainable Transportation (www.asla.org/sustainabletransport) covers sustainable transportation planning, siting sustainable transportation infrastructure, designing safe and visually appealing transportation infrastructure, green streets and reducing the urban heat island effect.
  • Sustainable Urban Development (www.asla.org/sustainableurban) covers fighting sprawl, sustainable zoning, reusing brownfields, investing in downtowns, open spaces and sustainable urban design.
  • Livable Communities (www.asla.org/livable) covers sustainable land use, place making, green schools, sustainable housing, sustainable employment growth and health, safety and security.
  • Combating Climate Change with Landscape Architecture (www.asla.org/climatechange) covers site planning, open spaces, plant selection, stormwater management and other areas.

While the site is a little hard to navigate, (if you like what you see, I suggest you bookmark the above links to be able to find them again) this is a good resource that pulls a lot of varied information together into one area. It has potential to be not only helpful for designers, planners and people who speak the sustainability language, but also to be useful to vastly wider audience. I understand they are also always looking for new projects, research, case studies, etc. to highlight, if you want to contribute you can contact ASLA @ info@alsa.org

-Sara Putney