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.
Three
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
systems.Two 3RWW
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.
In
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.
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.
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.
According
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:
Click here to hear Janie talk about the green roof demonstration projects and their successes
Janie discusses retrofitting green roofs to existing structures
Greening the urban landscape for stormwater management and other benefits
Click here to hear Janie talk about what homeowners can do to get involved in stormwater management
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.

We have a 9,000 square foot green roof at our office in Hempfield, Westmoreland County. It is a tremendous stormwater management tool, and it was fairly easy to install on an existing building. The roof is very colorful with flowers and plants, and has attracted lots of honeybees!
Posted by: James W. Pillsbury PE | August 01, 2008 at 09:47 AM