LGA asked Janie French, Watershed Programs Manager at 3 Rivers Wet Weather, to explain one of their Low-Impact Development, Stormwater Best Management Practices projects, the Green Roof Demonstration Project.
Rivers Wet Weather is a Pittsburgh-based nonprofit that is committed to
improving the water quality in the region. One of the organization’s goals is funding Stormwater Best Management Practice
demonstration projects, where they focus on lot-level or Low-Impact Development
projects. Low-Impact Development projects control stormwater at the source and
attempt to find uses for it instead of letting it enter and overflow the sewer
demonstration projects that have been completed are the rain barrel
project with the Nine Mile Run Watershed Association in 2004, and the LID
green roof demonstration project on the Shadyside Giant Eage, Hammerschlag Hall on Carnegie Mellon University's campus, and the retrofitting of an existing commercial /residential
building on the main street of Homestead with a green roof.
Read about 3RWW Green Roof Demonstration Project here.
addition to funding the construction of these green roofs, 3RWW is funding the
development of monitoring projects by the engineering departments at the University of
Read an article about CMU’s roof.
Click on the link at the bottom of the page to read a report on CMU’s roof, see a picture, and to see a live web cam view of the roof.
See results from Pitt’s monitoring of the Shadyside Giant Eagle roof.
Pittsburgh experiences frequent “wet
weather” such as rain, thunderstorms, and snow that affects its aging
infrastructure due to the overwhelming amount of runoff that enters the combined sewer
overflows (CSOs) and sanitary sewer overflows (SSOs). Although Pittsburgh
Janie referred us to a report by Mike Plumb, legal intern for the Columbia Environmental Law Clinic working for Riverkeeper, for more information on how source controls can manage stormwater more efficiently and effectively. Plumb looks at how New York’s DEP was investing in what he calls “obsolete infrastructure” in the forms of end-of-pipe tanks and in-line storage for CSO overflows. Plumb’s research found that for every $1,000 invested in these projects, New York could decrease CSO overflow by 2,400 gallons per year, whereas the same investment in source controls would decrease this overflow much more significantly. Street trees would decrease overflows by 13,170 gallons per year, green streets by 14,800 gallons, rain barrels by 9,000 gallons, new green roofs by 810 gallons, retrofitted green roofs by 865 gallons, and incentivized green roofs by 12,000 gallons per year (Plumb, 2008).
Read more about other forms of green infrastructure source controls in Plumb’s report, “Sustainable Raindrops.”
Most green roofs require an insulation layer, a waterproof membrane, a root barrier to prevent the roots of plants from penetrating the waterproof layer, a drainage layer, a filter mat, soil and, of course, vegetation. The type of vegetation planted on green roofs depends on the climate in the area and the effects of the different types of vegetation on water retention and heat absorption. Green roofs can be either intensive or extensive, where intensive green roofs usually require a deeper soil layer because they are typically planted with larger plants with roots that run deeper. Intensive green roofs are often accessible to the public, acting as a “roof-top garden.” Extensive roofs are usually not accessible for people to walk onto and enjoy, but are less expensive to install.
The benefits of green roofs can be realized at the private or building-level, and the public, or city-level. At the private level, green roofs require a larger initial investment, but they are estimated to extend the life of the roof twice as long, and they contribute to savings on energy costs, heating and cooling costs, and stormwater costs. Additionally, they provide sound insulation and aesthetic value, and intensive green roofs and rain gardens can be used for food production and can create a place for “community involvement” among employees of the building, boosting employee morale.
At the public level, green roofs can significantly reduce stormwater runoff and the impact on sewer infrastructure from too much water in the system, and they can reduce the urban heat island effect, reduce greenhouse gases, and improve air quality by replacing traditional, heat-absorbing roof surfaces with vegetation that cool the air through evapotranspiration (or evaporation of water from leaves). Greening the urban environment also improves the aesthetic quality of the city. The costs of green roofs at the private level would be the higher initial cost of the green roof and maintenance, and the costs to the public sector are those relating to program administration and start-up. However in both instances, the argument is often made that the benefits outweigh the costs.
Read more about how green roofs are built and the benefits they offer by visiting the “Green Roofs for Healthy Cities” website.
our interview with Janie, she noted that the major barrier for green roof
implementation in the southwestern Pennsylvania region is funding. We discussed the Green Roof Grant Program in Chicago as an example of a way to use incentives to fund green roof projects.
Read about the Chicago Green Roof Grant Program.
We have identified some available funding sources through the Pennsylvania state and federal governments:
Pennsylvania has grants and reimbursements awarded through the Stormwater Management
Act 167 where local governments can be reimbursed for 75% of the money they
put into a watershed protection program. In
Allegheny County, Conservation Consultants Inc. received $54,128 through an Energy Harvest
Grant for a 1,700-square-foot green roof, and Phipps Conservatory and
Botanical Gardens received $250,000 for an integrated water management system.
This system is used for geothermal heating and cooling, but also treats and
reuses wastewater. Growing
Greener II Grants, which give “$625 million to clean up rivers and streams;
protect natural areas, open spaces and working farms” can be used for green
roof demonstration projects and green infrastructure conservation projects.
The EPA also awards grants for green roof demonstration projects and other green infrastructure projects under its Nonpoint Source Management Program. “Under section 319, State, Territories, and Indian Tribes receive grant money which support a wide variety of activities including technical assistance, financial assistance, education, training, technology transfer, demonstration projects, and monitoring to assess the success of specific nonpoint source implementation projects.” Funding from the EPA can also be obtained through the Drinking Water State Revolving Fund; Source Reduction Assistance Grants; Surveys, Studies, Investigations, Demonstrations, and Special Purpose Grants ; and Air Quality Grants. This grant money can be received through PA’s Department of Environmental Protection.
to Katrin Scholz-Barth, expert and consultant for green roof
installation, extensive green roofs are, “the single most effective solution to
stormwater management,” because they do not take up additional land, are easily
adaptable and are economically efficient, they are not difficult to add to
architectural designs, and they are easily retrofitted to existing structures.
For a developed city with a lot of existing buildings in need of renovations, Pittsburgh is a good
Read more about green infrastructure in this report from the Natural Resources Defense Council.
Finally, Janie informed LGA how individual homeowners can become involved in managing stormwater. In addition to rain barrels, we discussed rain gardens and water conservation and water quality protection behaviors that any homeowner can engage in.
View 3RWW’s education and outreach materials, including their “Role of the Homeowner” guide.
Read an article on
planting rain gardens and Three Rivers Rain Garden Alliance.
* The construction of the rain garden at Phipps has been delayed *
Read an article
about a new rain garden on Mount Washington.
The Pittsburgh region can focus on greening the urban landscape with various forms of green infrastructure, such as trees, vegetation, wetlands, and open space that can be preserved or created in built environments, because not only does green infrastructure contribute to stormwater management, it also aids in energy efficiency, causes a reduction in the urban heat island effect, and holds a greater aesthetic value than vast landscapes of concrete.
Listen to clips from an interview with Janie French on the 3RWW Green Roof Demonstration Project and what the city and homeowners can do to help control stormwater:
To read more on stormwater management in the southwest Pennsylvania region, read the LGA Lyceum piece “This needs to sink in” by Stan Kabala, Center for Environmental Research and Education, Duquesne University.
To learn about the use of adaptive governance for stormwater management, please visit the LGA Adaptive Governance wiki.