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.





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





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





Opportunities

9 11 2009

Are words necessary?

curb and gutter

green street





Sustainable Site Strategies: Rosemary Beach, Florida

2 11 2009

Rosemary Beach-050
Rosemary Beach-099

I recently returned from a relaxing week long family vacation in Rosemary Beach, Florida, located on the panhandle just west of Panama City Beach. For those of you not familiar, this is a traditional neighborhood development established in 1995 complete with a Town Center that includes a post office, retail and restaurant space, a hotel, neighborhood parks and more. Many people choose to spend their vacation here for obvious reasons: sun, sand, surf and swimming pools but let’s review what visitors may not notice during their stay.

The following is from the RB website…

“Natural foliage creeps into the pervious pavement streets to slow what little motorized traffic finds its way into town, and keeps drivers alert – a conscious effort to create a safe environment for foot and bicycle traffic. Go green and get pampered at Rosemary Beach!”…

As stated, the streets are constructed of pervious concrete, which allows stormwater from frequent rain showers to penetrate through the pavement and directly into the sandy soil base rather than sheet drain to the typical/conventional system of numerous curb and gutters, inlets and concrete pipes. This isn’t to say there aren’t any storm sewer pipes as part of the infrastructure, just less because of an alternative stormwater solution. The average person visiting Rosemary may only notice that the driving surface is not asphalt and is more ‘bumpy’ that typical concrete.

In addition to pervious concrete, the use of native vegetation is another sustainable site strategy. Using native vegetation requires less water and maintenance while supporting bio-diversity of local wildlife species. Sidewalks, neighborhood boardwalk paths and parks are lined with plants that seem to have been there prior to development and give the impression that the buildings were somehow built around them. Live Oaks create a dramatic tunnel effect over the sidewalks while providing habitat for wildlife such as birds and squirrels. Lizards appear to love hanging out under the low growing palm shrubs and other native plant material. The careful planning of plant material size, location and scale of streetscape planting also aids in the slowing of motorist traffic by psychological affect.

These are only two simple sustainable site strategies/design elements that may go unnoticed by the typical visitor but could serve as an example of how to develop in the future. By the way, I did have fun and relax with my family and didn’t spend they whole week analyzing better ways to develop.

Brian Hudson





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