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Environmental Protection
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CLIMATE READY

.WATER UTILITIES

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SUSTAINABIL1TY BRIEF: GREEN INFRASTRUCTURE

Green infrastructure is an approach that uses either natural systems or engineered systems that mimic natural processes to
control runoff and reduce water demand. The implementation of green infrastructure helps to address current challenges
related to stormwater collection and treatment, limits floods from peak flows into surface waters following storms, augments
groundwater supplies in shallow aquifers and supports source water protection efforts. Projected changes in precipitation
patterns from climate change will exacerbate these existing challenges. Green infrastructure can be particularly effective when
considered as part of a suite of options. For example, in conjunction with water conservation and infiltration/inflow reduction
programs, it can be highly effective in reducing flow volumes.

BENEFITS OF GREEN INFRASTRUCTURE AS PART OF AN ADAPTATION PLAN

•	Increase collection capacity: Reducing runoff volumes and rates through incorporation of green infrastructure within
a service area decreases the overall flows into collection systems. This reduction of influent volumes can lower the
frequency of combined sewer overflows and raw sewage backups as well as potentially reduce the need for infrastructure
maintenance and expansion.

•	Increase resilience of service: Facilitating groundwater recharge and reducing peak runoff flows may effectively reduce
drought and flood-related service interruptions. Providing risk reduction through green infrastructure could improve
the performance of other adaptation options to mitigate floods and droughts under projected climate conditions (e.g.,
combine rain gardens with stormwater storage to handle larger storms with current treatment capacity).

•	Enable incremental expansion of service: Green infrastructure installations can be added as needed in areas that
are not directly connected to existing infrastructure. In many cases, this decentralized approach allows for greater
flexibility, faster implementation and lower costs than traditional grey infrastructure because it avoids building additional
connections to the collection system.

•	Decrease carbon footprint: Implementing green infrastructure projects can reduce collection and treatment needs,
thereby reducing the utility's associated energy demand and greenhouse gas emissions. These projects can also help
reduce the urban heat island effect—green roofs and other vegetation have been shown to keep buildings cooler during
hot weather, reducing energy costs and emissions.

•	Leverage opportunities for co-benefits: The costs of pursuing green infrastructure strategies may compare favorably
to expanding or upgrading facilities when considering averted costs and additional benefits to the utility and larger
community (e.g., air pollutant reductions and fewer odor complaints). The longer-term benefits from green infrastructure
projects may become more apparent when costs and impacts of different options are assessed across multiple economic
dimensions (e.g., public services, public health and ecosystem services).

•	Improve public image: Many green infrastructure projects provide aesthetic enhancement to communities, particularly
when compared with expansion of the built environment. Successful projects can make communities more attractive,
increase property values, increase public safety and serve as visible reminders that a utility is pursuing adaptation
holistically.

GETTING STARTED WITH GREEN INFRASTRUCTURE

Green infrastructure strategies can be pursued at various scales, either at utility facilities or throughout the community
and service area. Depending on current or anticipated challenges and available resources, utilities may want to build on
strategies that have been successful in the past or pursue new options. The following steps will help utilities get started
with green infrastructure:

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GETTING STARTED (continued)

•	Assess Current Challenges and Opportunities: Assess the current state of green infrastructure in the utility and
surrounding community and develop an awareness of local ordinances, regulations and building codes that may
impact pursuit of green infrastructure. In addition, examine system performance in light of current and projected
climate conditions (risk assessment) to identify potential needs with respect to runoff control and gauge the
suitability of facilities or service area for green infrastructure implementation.

•	Evaluate Budgets and Funding Opportunities: Weigh costs and benefits to consider green infrastructure as part
of existing utility plans to improve and maintain facilities. Available funding for projects from government and
other assistance programs may be a critical factor in identifying options and potential partners for both incremental
improvements to current facilities and new projects (see funding section below).

•	Identify Strategies: Based on the steps above, develop criteria and identify specific activities or projects to support
pursuit of adaptation options from the tables below. Review available resources, including case studies of effectively
implemented green infrastructure strategies at other utilities. Successful approaches will vary depending on location
and utility size, but the experiences of similar utilities and local governments should help identify appropriate strategies.

•	Plan to Involve the Community: Partner with community groups to implement and maintain green infrastructure
projects more effectively. Potential partners for projects may include city government, local watershed groups,
environmental nonprofits, local businesses, private developers, and community and neighborhood associations.

ADAPTATION OPTIONS
(SUSTAINABLE PRACTICES)

Options for including Green Infrastructure in an overall adaptation strategy are provided
in the tables below. Relative costs are provided on a qualitative scale ($ to $$$), and
indicates that an option could be considered a "No Regrets" strategy. For more
information on No Regrets options, see Page 11 in the Introduction.

Click on the @ icon to review the relevant Sustainability Brief.

GREEN INFRASTRUCTURE - PLANNING



Categorize existing and future conditions for land use and cover in watershed or collection area.

$



Map land use with respect to impervious surfaces and potential sediment inputs.

$



@) Research use of green infrastructure to meet compliance needs, such as MS4 permits.

$



^ Compare green infrastructure approaches with alternatives in terms of costs and benefits in
^ response to challenges.

$



@1 Improve precipitation and collection models to inform runoff and influent predictions.

$



|®| Design stormwater retention practices (e.g., rain gardens, green roofs) for flood prone areas (MS4s,
^ CSO area) as part of planned improvements to collection in service area.

$



^ Conduct audit of facilities and overall system to determine suitability for new green infrastructure
^ projects (e.g., green roof) and information needs to develop plans.

$



1^1 Train utility staff on green infrastructure technologies and maintenance.

$



Meet with community and local government officials to understand green infrastructure policies,
^ practices and standards, assess local codes and regulations and to identify opportunities to
overcome any existing barriers to green infrastructure.

$



Establish relationships with industries, local universities, businesses, and developers to collaborate
on strategies to reduce stormwater runoff and flood damage (e.g., green roofs, bioswales) and
provide necessary care-taking and maintenance.

$



Participate in community dialog to ensure green infrastructure is part of municipal modernization
@1 and upgrades to services and evaluate opportunities with other municipal services to leverage
existing funds for green infrastructure opportunities.

$-$$



Investigate and define proper metrics, based on experiences of similar communities, to evaluate
^ performance of green infrastructure projects.

$-$$

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GREEN INFRASTRUCTURE - OPERATIONAL



Reduce infiltration / inflow by preventing illegal connections and leaks (e.g., grouting connections,
^ sliplining, using watertight manhole covers) to reduce stormwater inflow volumes.

$-$$



Implement infiltration or recharge projects to reduce stormwater discharges or maintain groundwater
table.

$$-$$$



|5c| Place filter strips or shoreline vegetation around surface water bodies or collection infrastructure
^ vulnerable to sedimentation.

$$



Install rainwater harvesting and retention (e.g., rain barrels, green roofs) at current or planned
^ facilities.

$$



Implement adaptive water rates to correspond with water supply.

$



Encourage water conservation on-site by employees and reduce water use on utility grounds by
limiting irrigation and choosing native plants.

$



Develop communications package for customers promoting incentives and available equipment for
rainwater collection and water conservation practices.

$-$$



|®| Support green infrastructure development with large water consumers (e.g., industries, local
^ universities) and land developers.

$$





GREEN INFRASTRUCTURE - CAPITAL/INFRASTRUCTURE

COST



|»l Improve stability and permeability of soil at facilities and in public areas to reduce runoff into
^ stormwater collection system and surface water bodies.

$-$$



^ Build new stormwater retention structures (e.g., rain gardens, ponds) as part of planned
^ improvements to collection in service area.

$$$



^ Support green infrastructure projects in the community as part of modernization and upgrades to
^ services.

$$-$$$



@) Replace current paved surfaces (e.g., service roads and parking lots) with permeable surfaces.

$$-$$$

EXAMPLE 1

The City of Portland, Oregon, like many major U.S. cities, has experienced challenges related to combined sewer

overflows and overall watershed health. The City Bureau of Environmental Services began a stormwater program in the

1990s and continues to implement green infrastructure solutions through the Grey to Green Program, which began in

2008, to help manage runoff and keep local rivers clean:

•	From 1993 to 2011, the Downspout Disconnection program encouraged homeowners to redirect roof water to lawns and
gardens, diverting approximately one billion gallons of stormwater per year from the combined sewer system.

•	Green retrofits to streets have included landscaped curb extensions, swales, planted strips, pervious pavement and trees.
Currently, the City has over 1200 green street facilities helping to manage stormwater.

•	The City offers incentives via floor area bonuses to developers that pursue eco-roofs. As of July 2012, developers have built
355 eco-roofs that add more than 17.1 acres of green space.

•	The Clean River Rewards program gives discounts on stormwater utility fees to homeowners that manage roof runoff by
increasing pervious surfaces on their property.

•	Active monitoring of projects has led to an increased understanding of effectiveness and the ability to refine projects as
needed based on collected data.

•	Acquisition of 318 acres of land and revegetation of natural areas are helping to control erosion and restore overall
watershed health. Specific benefits of the current $5.6 million East Lents Floodplain Restoration project will include
reduction of flooding frequency, improved wildlife habitat, stream bank stabilization, improved air quality and area

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EXAMPLE 1 (continued)

revitalization. Phase 1 of the project is funded by a $2.7 million grant from the Federal Emergency Management Agency
through its Pre-Disaster Mitigation Grant program

• Partnerships with local schools have allowed green projects to be used as educational opportunities for students and their
families.

The success of green infrastructure in Portland is a result of many factors, including the City's multidisciplinary approach,
the use of policy and incentives to encourage behaviors, and the use of monitoring data to continually refine approaches.
The benefits of green infrastructure, including gains in watershed health, regulatory compliance, city livability and property
values, are detailed in the 2010 report Portland's Green Infrastructure: Quantifying the Health, Energy, and Community Livability
Benefits. Moving forward, the City of Portland plans to continue to use green infrastructure as an integral part of its stormwater
management program.

EXAMPLE 2

The Milwaukee Metropolitan Sewerage District (MMSD) is complementing its past infrastructure investments with new
investments in green infrastructure. These new projects have improved the effectiveness of the system during increasingly
large storm events and maintained the provision of cost-effective water management services for the Milwaukee, Wisconsin
region. Through prior efforts, MMSD decreased the number of system overflows from 50 to 60 per year before 1993 to a
rate of just over two per year today. These efforts included 405 MG of inline storage constructed for just under $1 billion
as part of the 1993 Water Pollution Abatement Program, 27 MG of additional storage built through the 27th Street Inline
Storage System extension for $98 million and 80 MG of remote storage added for the northwest section of the service area for
$161 million. The resulting $3 billion worth of infrastructure reduces the negative impact of wet weather events significantly.
Looking forward, MMSD aims to eliminate overflows by 2035, in part, by integrating green infrastructure into overall system
management and meeting its discharge permit condition to capture 1 million gallons per year over the next five years
using green infrastructure. MMSD research results indicate that green infrastructure can be effective in reducing runoff and
sediment loading while saving tunnel pumping costs, creating jobs, benefiting public health and improving community
aesthetics. Recent MMSD accomplishments through green infrastructure practices include:

•	Nearly 1 million gallons of stormwater prevented from entering the sewer system through distribution of almost 18,000 rain
barrels throughout the city over the course often years. With the help of a local community service corps, MMSD purchases
and retrofits reclaimed food grade barrels and then either sells or donates rain barrels to customers and community schools
and groups.

•	8.4 acres of new green roofs in Milwaukee through a popular program, where MMSD matches funds to build green roofs
on public and private buildings. A number of large manufacturing companies have constructed green roofs, and the public
housing agency also considers green roofs on all new buildings.

•	Protection of more than 2,400 acres of upstream wetlands and adjacent areas to filter stormwater pollution through the
Greenseams® program, a partnership and land conservation program that aims to manage the percent of impervious
surfaces in the watershed by keeping key open spaces open and undeveloped. MMSD spends an average of approximately
$7,400 per acre on these plots of land, restores them if necessary, and then turns the land back over to the community or
land trust to manage, ensuring that the land remains undeveloped.

More information can be found in MMSD's plan for Sustainable Water Reclamation.

EXAMPLE 3

New York City's Department of Environmental Protection (NYC DEP) is implementing a number of strategies to enhance the
city's resilience to climate change, including the New York City Green Infrastructure Plan, a comprehensive 20-year effort to
meet water quality standards. The goal of this plan is to capture stormwater runoff through green infrastructure projects
(e.g., rooftop gardens, retrofitted buildings, swales) to reduce combined sewer overflow occurrences during heavy rain
events. This cost-effective, community friendly program is an adaptive framework that can be modified to help New York
City meet its adaptation goals. In March 2012, the plan was incorporated into a consent order with the State that would
eliminate or defer $3.4 billion in traditional investments, and implementation of the initiatives in the plan would result

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EXAMPLE 3 (continued)

in approximately 1.5 billion gallons of CSO reductions annually by 2030. The Green Infrastructure program leverages the
established Greenstreets program, a collaboration between NYC Parks and NYC Department of Transportation that began
in 1996. Greenstreets, which turns unused areas into green spaces, started as a way to beautify neighborhoods and improve
air quality and, in 2010, became part of NYC DEP's Green Infrastructure Program to include additional stormwater benefits.
Green infrastructure projects are currently being implemented and monitored in NYC DEP-designated priority sewersheds
to understand and maximize benefits to the watershed.

In addition to green infrastructure, New York City is also expanding its Bluebelt program to enhance drainage in areas of
the city that currently experience street flooding. These Bluebelts are natural areas that often enhance existing drainage
corridors (such as streams, ponds and other wetland areas) to capture additional stormwater in place of installing new"grey"
infrastructure. The first Bluebelt was constructed in Staten Island; almost 10,000 acres are currently in place. NYC DEP is
currently constructing new Bluebelt systems in Staten Island and in Twin Pond, Queens, with plans to construct additional
Bluebelts in Staten Island and the Bronx in the future (NYC 2013).

ADDITIONAL RESOURCES FOR GREEN INFRASTRUCTURE
f

PUBLICATIONS

•	EPA's Green Infrastructure webpaae

•	Green Infrastructure (American Society of Landscape
Architects)

•	Sustainabilitv in the Water Sector (International Water
Association)

•	Low Impact Development Center publications

Stormwater Strategies (Natural Resources
Defense Council)

Rooftops to Rivers II (Natural Resources Defense
Council)

Integrating Valuation Methods to Recognize
Green Infrastructure's Multiple Benefits (Center
for Neighborhood Technology)

TOOLS

EPA Green Infrastructure - Links to Modeling Tools

Smart Growth/Smart Energy Toolkit: Low Impact

Development (State of Massachusetts)

National Low Impact Development Atlas (University of

Connecticut)

National Green Values™ Stormwater Management
Calculator (Center for Neighborhood Technology)

Green Roof Energy Calculator (Portland State
University

GIS Mapping Data on Existing Impervious Cover:
National Land Cover Database

International Stormwater BMP Database
Stormwater Report website (Water Environment
Federation)

EPA Green Infrastructure: Funding Options

EPA Clean Water State Revolving Fund (with
information on EPA Green Project Reserve)

EPA Drinking Water State Revolving Fund
Financing for Environmental Compliance -
Water Resources and Tools (EPA)

FUNDING

EPA Tools for Financing Water Infrastructure
USDA Rural Development Grants
University of North Carolina Environmental
Finance Center

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