Metro Green Infrastructure Master Plan Now On-line

1 09 2010

Metropolitan Nashville-Davidson County’s Green Infrastructure Master Plan is now available on Metro Water Services’ website. The plan was prepared by amec, Hawkins Partners, Urban Blueprint, and the Low Impact Development Center. The plan includes the following:

  • Green Infrastructure Practice – Overview of Green Infrastructure and descriptions of various practices.
  • Technical Analysis of Green Infrastructure – Analysis of the CSS area with respect to green roofs, three kinds of infiltration practices, tree planting, and rainfall harvesting (cisterns and rain barrels) and its potential impacts on the CSS.
  • Green Infrastructure Projects – Brief overview of the preliminary design concepts for six projects.
  • Green Infrastructure Incentives and Financing – Summary of various potentially applicable incentive practices that have been applied in other cities to encourage the use of Green Infrastructure.

Click here to download the entire plan in PDF format





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.





New Downtown High-rise Includes Green Roof

30 11 2009

The Pinnacle at Symphony Place, a 29-story office building in downtown Nashville, opened this month. The building includes 520,000sf of Class A office space. It is home to law offices of Bass Berry and Simms and the headquarters of Pinnacle Financial Partners. The building designed by the award winning architectural firm Pickard Chilton with Nashville architects EOA Architects is anticipated to receive LEED-Silver certification from the United States Green Building Council (USGBC). With the inclusion of a 28,000sf rooftop garden, the building contributes significantly to Nashville’s ever growing green infrastructure

The green roof, designed by our office, is located on the 7th floor above the parking garage and includes a series of spaces that can be enjoyed by the building’s tenants. The area is comprised of 9,400sf of pedestal pavers and 19,000sf of vegetated areas. One hundred percent (100%) of the pavers were selected to exceed the minimum solar reflectance standards established by the LEED rating system. The striping pattern continues the prominent vertical fins on the facade of the building into the rooftop garden area. The planting areas are a combination of extensive green roof (planting media depths ranging between 5-9”) and semi-intensive areas (planting media depths ranging between 18”-30”). The semi-intensive areas were planted to reflect a more traditional landscape around each of the gathering areas and provide areas for trees to shade and scale the spaces. In an effort to establish a more pedestrian scaled environment and additional interest a series of 12ft pyramidal trellis structures were incorporated in the extensive green roof areas.

It is estimated that the green roof can retain nearly 67% of the annual rainfall falling directly on it. In addition, it reduces the peak flows, is significantly cooler than neighboring conventional roofs, reduces thermal heat gains in the water that enters the stormwater system, and provides a beautiful space to look upon and enjoy.

We are honored to have been a part of such an exciting project and look forward to watching it grow. We have been pleasantly surprised by the significant growth the plant material has shown in a short time period. As it matures, we will keep you up to date on its progress.

-Brian Phelps





Educational Awareness and Green Infrastructure

26 10 2009
While attending the recent Tennessee ASLA conference, and sitting in on a lecture about native plants, a presenter made an offhand comment stating that public education is the most important thing we can do to raise awareness, because if people don’t know about things then how can we expect them to care? Whenever possible, HPI has incorporated interpretive graphics into public projects such as greenways or parks, to highlight the history of the place or unique features of the site. Recently we have been provided the opportunity to create educational signage about sustainability for two newly completed projects – the first for a private developer and installed at Hill Center Belle Meade and the other for the City of Nashville for the renovation of Deaderick Street.

Environmental Stewardship campaigns have been around a long time with recycling awareness programs, Arbor Day, etc. Incorporating educational signage about sustainability into the built environment adds another facet to this type of non-formal education for the general pubic and is another perfect opportunity for landscape architects to become involved. Some traditional public awareness methods require the people to find their way to specific websites (the EPA has a couple of great sites geared towards the younger age groups; Environmental Kids Club or Polluted Runoff) or people have to just happen see things in the media. While these are all good, they may make it hard to target a wide range of groups.

The cool thing about putting educational posters in the built environment is the wide audience that you can target. For instance, a lot of different people on their way to the supermarket in Hill Center Belle Meade, or to their office buildings or the theater on Deaderick Street, will walk by these signs everyday. We just hope it sparks interest and provides a topic of conversation to raise even more awareness for sustainable practices.

Rainwater Harvesting Sign at Hill Center Belle Meade

Rainwater Harvesting Sign at Hill Center Belle Meade

Highlighting the Sustainable Practices in Deaderick Street Construction

Highlighting the Sustainable Practices in Deaderick Street Construction





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.