Eco-roofs in Portland: Creating Habitat [VIDEO]

2 04 2010

Screenshot of KGW News Story

I came across this news segment from KGW News in Portland regarding the City’s eco-roof initiative and the recent visit by Dusty Gedge, president of the European Federation of Green-roof Associations. In addition to many of the other benefits of green roofs, the city is also promoting the creation of eco-roofs to establish habitat for dry riverbed species in particularly the diverse species of birds that migrate through the city. I couldn’t embed the video but here is a link to it and the transcript.  Tom Liptan, an Environmental Specialist with Portland’s Bureau of Environmental Services, summed it up well by saying.

“The benefit of an eco-roof is that it provides habitat for various species that are losing that kind of habitat in most urban environments around the world.”

-Brian Phelps






Zoning and Pervious Pavement

19 03 2010

This month, the topic of APA’s Planning Advisory Service’s column, “You Asked, We Answered”, is how zoning codes across the country are handling pervious pavement for parking and sidewalks. The links to the various zoning codes were very useful. The following are excerpts from some of the more interesting ones.

ASHEVILLE, NC

“Porous paving blocks and pervious paving materials are permitted and encouraged as material for parking lots. The use of grass as a parking lot surface is permitted for overflow and intermittent parking. Pervious paving systems are required for parking spaces which exceed the maximum number of spaces required by subsection 7-11-2(c). The use of grass or other vegetation as a parking surface is permitted only for parking spaces which are provided in excess of the maximum number of parking spaces required by subsection 7-11-2(c) or used for intermittent or overflow parking. Parking lots associated with arenas, sporting facilities, amphitheaters, fairgrounds, and religious institutions may, however, use grass or other vegetation for the entire parking lot.”

DOUGLAS COUNTY, MN

Impervious Surface Replacement. Existing properties exceeding the standards for impervious surface coverage present a distinct management challenge from that of newly developed properties and there is a need to establish clear and consistent guidelines for how re-development of these lots may occur.

1. The applicant removes existing impervious surfaces at a ratio of one and one-half (1.5) square feet removed for every one (1) square foot added and restores these areas to a permeable surface…

…a. Permeable pavement systems are encouraged in the management of sites currently over the impervious surface limit and shall be credited as twenty-five (25) percent pervious for these sites when installed according to the requirements of

Section V.L.4.a.(2.)(d.)iii. Applicants are encouraged to replace existing impervious surfaces with natural vegetation at the 1.5 to 1 ratio listed above, however, permeable pavement systems may also be used. In these cases they are to replace existing impervious surfaces at a ratio of at least four (4) square feet converted for every one (1) square foot of new impervious surface being added;

2. The applicant removes existing impervious surfaces at a 1:1 ratio and restores those areas to a permeable surface and in addition, submits a comprehensive stormwater management plan that emphasized infiltration and onsite retention of stormwater for at least the two year 24-hour storm event through a combination of methods including buffer strips, swales, rainwater gardens, permeable pavement systems and other low impact development methods. The stormwater management plan must be designed by a registered engineer or landscape architect and installed as designed by a qualified professional.

a. Permeable pavement systems may be considered as 100% pervious when submitted as part of a stormwater management plan consistent with this section…

FT. WAYNE, IN

If construction techniques such as pervious pavement, block and concrete modular pavers, and grid pavers are used for off-street parking surfaces, each space provided as a result may serve in lieu of two (2) required off-street parking spaces, up to a maximum of 10% of the number of required spaces…

…Paving and drainage. All land which is placed in use for off-street parking and all driveways serving parking, delivery, and loading areas, shall be paved with asphalt, concrete, or other approved all-weather hard surface, including construction techniques such as pervious pavement; block, concrete, and similar modular pavers, and grid pavers; and shall be drained with materials and in a manner which meets the current minimum standards and specifications for parking areas adopted by the Board.

-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





Clarifying EPA’s Jurisdiction Under The Clean Water Act

3 03 2010

Supreme Court Building
Credit: istockphoto.com/diademimages

On Monday the New York Times ran an interesting article as a part of their Toxic Waters series. The article titled “Rulings Restrict Clean Water Act, Foiling E.P.A.” reported on the difficulties regulators are having implementing the intent of the 1972 Clean Water Act. The difficulties stem from the Supreme Court’s decision in 2008 questioning the definition of  “navigable waters” in Rapanos v United States and Carabell v United States Corp of Engineers. The court was split (4-1-4) on whether the wetlands in question were under the jurisdiction of the Clean Water Act since they were not directly adjacent to a navigable waterway.

The Clean Water Restoration Act (text here) introduced into Congress last year by Senator Russ Fiengold, D-Wisconsin and Rep. Jim Oberstar, D-Minnesota seeks to clarify this definition. Clarifying the definitions of the EPA’s jurisdiction would facilitate the implementation of the Clean Water Act and allow regulators to make decisions. The bill has passed the Senate Environmental and Public Works Committee, but has been placed on hold by Senator Mike Crapo, R-Idaho.

I am curious about the timing of the NYT article and wonder if there will be any action on the Clean Water Restoration Act in the near future. Obviously, the decision could have a profound impact on the EPA’s jurisdiction.

For more information I came across this analysis of Rapanos v United States and Carabell v United States Corp of Engineers from the Harvard Environmental Law Review. You can also find the EPA’s current clarifications on “Waters of the United States” on their website here.

-Brian Phelps





Rainwater Harvesting Commercial

26 02 2010

I know this video has been out a while (since 2007). I recently ran across it again on Youtube and thought it would be worth sharing. The video is a 90-second public service commercial that promotes urban rainwater harvesting in India. It was created for/or by  The Centre for Science and Environment (CSE), a public interest research and advocacy organisation based in New Delhi. It is a simple but powerful message. Enjoy.

-Brian Phelps





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





Olympic Sized Green Roof

17 02 2010

Courtesy Vancouver Convention Centre website

The winter Olympics just kicked off with the opening ceremonies from BC Place Stadium in Vancouver. But serving as the International Broadcasting hub for the games is the Vancouver Convention Centre — the world’s first LEED Canada Platinum rated convention building. The 1.2 million SF center boasts a 6-acre green roof, which also now makes it the largest green roof in North America.

The roof is planted with over 400,000 native plants and collects rainwater for irrigation which contributes to the buildings stormwater credits as well. Other interesting sustainable features include marine and shoreline habitat restoration. Fish habitat was actually built into the buildings foundations. The building also uses seawater for heating and cooling and incorporates on-site water treatment.

The following video “Vancouver’s 6 Acre Living Green Roof”, posted on You Tube gives a great sense of the scale and context of the green roof. The landscape architect who worked on the project, Bruce Hemstock, discusses the plants used, soil media and the idea behind habitat linking into urban centers that is beginning to be made possible with the inclusion of more green roof in our cities. Interestingly enough he says one of the biggest challenges of the project was initially convincing people that it was the right thing to do.