Chicago, Illinois

Becoming the "Greenest City in America"


Chicago's first green roof, atop City Hall
Chicago's first green roof, atop City Hall

Chicago's popular nickname is the "City of Broad Shoulders." But, since Mayor Richard M. Daley took office in 1989, the City has sought to remake itself as "the Greenest City in America" through the implementation of a comprehensive environmental agenda that addresses energy and green building, transportation and energy use, and infrastructure and resource management - including water quality.

Chicago has been working toward these goals for close to two decades. The City's success is not simply the consequence of perseverance. Rather, it is an outgrowth of a well-orchestrated strategy that combines:

  • Mayor- and Cabinet- level leadership
  • An environment that is an incubator for new ideas
  • Action plans and measurable, quantifiable outcomes
  • Incentives for innovation and adoption of green practices, with rewards for those who "get it right"
  • Strategies for bringing new ideas to the community
This success is also the result of an intentional linking of sustainable or green practices with green economics, an improved business climate and quality of life for both residents and visitors.

The Mayor has set the bar high, establishing the goal of making the city ".the greenest, most environmentally friendly city in the nation." In his many speeches and presentations, he emphasizes that a 21st century metropolis must go beyond beautification and make environmental initiatives an integral part of a long-term strategy for growing economic and social health.

To that end, says the Department of the Environment First Deputy Commissioner, the City is working "to bring industry back to Chicago while also revitalizing local ecology." The mayor is committed to making the city a national model of how industry and ecology can exist side-by-side." For Chicago, having a green city mans having a green - and more competitive - economy. These changes allowed Chicago to out-compete Denver to become the new headquarters for the Boeing Corporation, based on its quality of life and ability to "walk the sustainability talk."

The Mayor has played a very strong leadership role throughout, although day-to-day operations are directed by the Department of the Environment (DOE), a Cabinet-level agency that administers programs to protect and restore Chicago's natural resources, reduce waste, clean up brownfields, promote energy efficiency and reliability, educate the public about environmental issues, and enforce the City's environmental protection laws. Led by a Commissioner with a passionate commitment and established track record in sustainable practices - and for whom green living is a personal way of life - DOE has emerged as an innovator in green infrastructure practices. The Mayor's leadership, coupled with the role of DOE as an incubator and tester of new technology, has proven to be a powerful combination in Chicago's success.

This case study shares some of Chicago's efforts and lessons learned in developing a comprehensive environmental agenda, including elements that address urban stormwater. In this case, being a part of a larger action agenda has helped the City's water quality initiatives to gain visibility and public support.

A key motivator for green infrastructure: Combined Sewer Overflows

Chicago was founded at the confluence of the Chicago River and Lake Michigan. The first city neighborhoods were constructed by filling in what was once a large wetland area. To avoid flooding, the City's first stormwater conveyance system was built in 1856, and, like most cities of its era, it was constructed as a "combined sewer overflow" (CSO) system, which conveyed both stormwater and wastewater through the same underground piping.

During large storm events, the combined sewers overflow and release untreated waste- and stormwater into the Chicago River, and, occasionally, residential neighborhoods are flooded. In the early 1900s, sewage and stockyard pollution from the Chicago River prompted Chicago officials to reverse the course of the South Branch of the river away from Lake Michigan, directing it instead towards the Mississippi River in an effort to improve the lake's water quality.

Water issues remain a concern for the city more than a century later. The city manages one of the largest wastewater collection and treatment systems in the world, with over 4,400 miles of sewage infrastructure that cost about $50 million annually to maintain. Urban runoff challenges are exacerbated by the magnitude of infrastructure needed to serve Chicago's population. Approximately 3 million people call Chicago home, and the population of the entire six-county metro region surrounding the city exceeds 8 million. The region's population is projected to increase 20% by 2030. Impervious surfaces cover approximately 58% of the city.

Like most cities with combined storm and sanitary sewer systems, Chicago has invested in a "deep tunnel" solution to expand capacity during significant flood events, and thus reduce the incidence of CSOs. The $3.4 billion Tunnel and Reservoir Plan (TARP), implemented under the leadership of the Metropolitan Water Reclamation District, was originally conceived in the late 1970s and has been constructed in phases. When complete in 2019, the system will handle most of Chicago's CSO discharges, storing combined runoff and sewage until it can be sent for secondary treatment at a wastewater treatment plant.

The "big pipe" is not viewed as the only solution, however - especially with completion of the system still years off. In 2003, with only part of the system operational, more than 44 billion gallons of stormwater were captured, yet 10 billion gallons were still released as CSOs. This state of affairs has encouraged the City to become a major promoter of landscape-based, green infrastructure approaches to stormwater management, which focus on runoff reduction and on-site detention, water quality treatment, and infiltration as sustainable practices that complement the ultimate hard pipe solution.

Early efforts: Restoring the City's tree canopy and greening its neighborhoods

Chicago's leadership as a major proponent of greening began with the Mayor's love of trees, and his commitment to working block by block to restore the urban forest. Soon after he was elected, Mayor Daley surveyed the metropolitan area and noticed how few trees remained, as compared to his memories of growing up in the City. Encouraged by the First Lady, an avid gardener, he began a program to beautify the city.

As he read about the benefits of trees and landscape plantings, the Mayor was impressed with their environmental benefits, such as their ability to mitigate heat island effects and to improve air quality, and their function in promoting the filtration of stormwater runoff. One of the earliest efforts undertaken, driven by Mayor Daley's new knowledge, was the Green Streets initiative, established in 1989, which focuses on improving the quality or urban life through tree planting, green space landscaping, community and volunteer greening programs, and a sidewalk and hanging basket flower program.

By 2006, over 583,000 trees had been planted, either by the City, or by private developers or homeowners. The environmental benefits produced by this endeavor were the equivalent of removing the pollution of 14,000 cars (City of Chicago, 2006). Other significant accomplishments include the following (City of Chicago, 2006):

  • Since 1997, 73 linear miles of medians have been constructed and planted with urban tolerant plants and more than 4,850 trees, diverting stormwater from the sewer system, cooling streets, and providing aesthetic benefits.
  • The City manages and cares for more than 538,000 street trees annually, an increase of 88,000 trees since the 1994 Tree Survey.
  • 13.8 percent of Chicago is covered by tree canopy, an increase of close to 3% since the City's 1994 Tree Survey.
  • Since 1991, the City's landscape ordinance has resulted in the planting of at least 47,000 street trees by the private sector.
  • GreenStreets has planted over 60,000 trees and hundreds of thousands of shrubs, vines, perennials, and annuals throughout the City's streets and neighborhoods, within the public right-of-way. In 2005, the City planted over 2,000 trees and 30,000 vine plants along Chicago's expressways to mitigate the heat island effect.

Continued leadership from the top: A cabinet-Level commitment

Chicago's first green roof, atop City Hall

The Mayor delegated primary responsibility for Chicago's "green infrastructure" initiatives within the Department of the Environment, a large agency with a broad environmental mandate that includes the following areas, among others:

Natural Resources and Water Quality—The Natural Resources and Water Quality Division sets policy, plans, and supervises activities designed to protect, restore, and enhance natural resources. This is the lead division within DOE charged with the testing and implementation of sustainable stormwater management practices. The Division's initiatives include greening neighborhoods through community education and provision of materials; managing grounds and public programming at the Chicago Center for Green Technology; and establishing policies and programs that conserve and enhance water quality in Chicago's rivers, lakes and groundwater systems.

Urban Management & Brownfields Redevelopment—The Urban Management and Brownfields Redevelopment Division evaluates, remediates and provides for the redevelopment of properties for City projects. The inclusion of brownfields redevelopment functions as part of the agency mission helps to encourage the implementation of sustainable stormwater management and "green infrastructure" practices as part of brownfields redevelopment.

Permitting & Enforcement—The Permitting and Enforcement Division exists to further compliance with the environmental provisions of the Chicago Municipal Code. All permits issued by the Division contain restrictive operating conditions that require best environmental practices. In cases where proactive permitting is inadequate to ensure compliance, the Division also has extensive enforcement capabilities. Twenty-three inspectors, investigators, and engineers are responsible for responding to complaints, inspecting sites, and, where appropriate, initiating enforcement actions. In 2003, the Division's field personnel inspected approximately 12,000 sites and issued approximately 1,000 citations. The Division also files dozens of lawsuits and administrative cases annually.

The inclusion of the permitting and enforcement functions within the same policy-making agency is unusual, but helps to ensure that requirements are followed. Gaps in communication that might have resulted from these functions being lodged in separate agencies are minimized.

Community Programming and Education Outreach—The Community Programming and Education Outreach Division increases public awareness of DOE's ongoing environmental, educational, and outreach initiatives.

As a Cabinet-level agency, DOE is on par with peer agencies such as Planning, Parks, and Public Works. As such, the City's environmental initiatives are not simply a subcategory of another agency's mission but are "front and center" and viewed as important as the provision of other public services in the City. While they still compete for funding with other initiatives, their inclusion as a major function of a Cabinet-level agency, coupled with the Mayor's commitment to sustainable infrastructure, means that water quality projects are accorded visibility and priority. The peer relationships with partner agencies also facilitate the use of public facilities, like parks and roadway rights-of-way, as testing grounds for new initiatives (read more below). Peer relationships with the Planning department help facilitate implementation of sustainable stormwater management practices within private development, once technologies have first been proven on City owned lands.

The Department of Environment as an incubator for new ideas and innovation

Rainwater is captured in cisterns to irrigate on-site gardens
Rainwater is captured in cisterns to irrigate on-site gardens

The Mayor's intense commitment to an economically and environmentally sustainable city has stimulated the Department of the Environment to become for testing new approaches. These tests are conducted first on City-owned properties. The overwhelming logic is: "If the City can do it, why shouldn't everyone else?" As with the first Green Roof, installed on Chicago's City Hall, the Mayor frequently poses challenges that push staff to implement projects that may initially be outside their comfort zone.

Virtually all of Chicago's green infrastructure initiatives for managing and cleaning urban runoff began as pilot projects. In 2003, based on their success and to encourage broad implementation, Mayor Daley published Chicago's Water Agenda through the Department of the Environment (City of Chicago, 2003), which describes the importance of sustainable management of water resources and outlines an action agenda. A companion volume outlines best management practices that have been tested by the City and that are suitable for implementation by developers and homeowners (City of Chicago, 2004).

The role of the City in "pilot testing" new technologies before encouraging broader implementation is embraced by DOE Commissioner Sadhu Johnston. Johnston joined the City team as the Mayor's Special Assistant for Green Initiatives and became Commissioner in 2005. Before that, he established a strong track record for green design while serving as executive director of the non-profit Cleveland Green Building Coalition. "It's about ecological designs," said Johnston. "It's about understanding how nature does its work and emulating it to do the work of cities." In practical terms, it means looking at "stormwater" in a new light - as rainwater that can irrigate gardens and flush toilets. It also means taking chances. "Where we're experimenting," Johnston said, "not everything is going to be a clear success."

This openness to innovation and repeated testing to "get it right," along with highly visible "stretch" challenges like installing the City's first green roof on - of all places - City Hall, has helped the City to build a culture that encourages excellence and success. Below are some of the more visible initiatives.

Chicago's first green roof, atop City Hall, is a model for biodiversity with over 150 plant species represented.
Chicago's first green roof, atop City Hall, is a model for biodiversity with over 150 plant species represented.

Chicago's Green Roof Program—Chicago's thriving green roof program began with a 20,300 square foot demonstration roof on City Hall, prompted by Mayor Daley's challenge: "Other cities do this - let's find a way to make this happen!" The green roof, designed by Conservation Design Forum, features some 20,000 native plants with over 150 varieties. It retains more than 75% of the volume from a one-inch storm, preventing this water from reaching the combined sewer system. Internal studies show a 50% reduction in stormwater runoff.

The success of this initiative prompted the DOE, in partnership with the City's Planning and Development Department, to launch a Green Roof initiative. The City led by example in constructing other green roofs on the Chicago Transit Authority headquarters, on DuSable Harbor, a park district facility, and on the Chicago Center for Green Technology (read more below). This latter installation involved extensive research; nine test plots were monitored to evaluate runoff reduction and pollutant removal.

The program has led to more than 80 green roofs in the city, totaling over 2.5 million square feet (City of Chicago, 2006). The city encourages the use of green roofs by sponsoring installations and demonstration sites and by providing incentives, including expedited permitting (read more below) and density bonuses. A density bonus is offered to developers who cover 50% or 2,000 square feet (whichever is greater) of a roof with vegetation. The City also provides $5,000 in green roof installation grants for small-scale commercial and residential properties. 20 grants were awarded in 2006.

Chicago's Green Alleys program replaces impervious alley surface with permeable pavement, allowing for infiltration of rainwater to green and sustain backyard gardens.
Chicago's Green Alleys program replaces impervious alley surface with permeable pavement, allowing for infiltration of rainwater to green and sustain backyard gardens.

The Green Alleys Program—The City has developed a pilot program that tests approaches to installing permeable pavement in residential alleyways. To address localized flooding caused by runoff from one alley in a North Side neighborhood, the city removed the asphalt from the 630 foot long, 16 foot wide alley and replaced it with a permeable paving system. Now, instead of generating stormwater runoff, the alley infiltrates and retains the volume of a three-inch, one-hour rain event. In this same ward, vegetated swales are also being used for stormwater management.

The success of the Green Alleys program has led to its being featured prominently in the City's 2006 Environmental Action Agenda (read more below). Other projects, such as implementation of porous paving in private and public parking areas, including the Chicago Department of Transportation facility in the 48th Ward, have also been featured.

Rain Gardens, Downspout Disconnects, and Rain Barrels—The City has developed a pilot "rain gardens" program, installing bioinfiltration areas within City properties and roadway medians, and the "Green Bungalows" program, which features green site design and building practices in four demonstration bungalows within the City. A next phase for these pilot projects has been included in the City's 2006 Environmental Action Agenda based on interest in these programs.

The City also actively encourages homeowners to disconnect their downspouts and direct rainwater to their yards or gardens. In the fall of 2004, City residents purchased more than 400 55-gallon rain barrels for $15 each. The program cost the City $40,000 excluding city labor. The Department of Environment estimates that this pilot project has the potential to divert 760,000 gallons annually from the combined sewer system, a relatively small number compared to the total amount of stormwater runoff in the City. However, the program targeted areas with a high frequency of basement flooding, meaning the program may have a more significant impact in these localized areas. Since the water in rain barrels can be used for other purposes such as landscaping, this program has the possibility for additional conservation benefits as well.

Chicago's emerging rain garden program is pilot testing installations in roadway rights of way, as in this image, and in private residential areas.
Chicago's emerging rain garden program is pilot testing installations in roadway rights of way, as in this image, and in private residential areas.

A 2004 Department of Environment Stormwater Reduction Practices Feasibility Study used hydraulic modeling to assess the effectiveness of best management practices for the Norwood Park sewershed (DOE, personal communication). The study found that downspout disconnection could achieve peak flow reductions in the 1,370-acre area by 30% for a six-month or one-year storm if all homes in the 80% residential area disconnected their downspouts from the sewer system. This would potentially reduce peak flow in the CSO outfall pipe by 20% and water levels in the sewer system by eight inches to two feet. The study also showed that three-inch and six-inch-deep rain gardens installed at each home could reduce total runoff by approximately 4% and 7%, respectively, for the same six-month or one year storm events.

Chicago Center for Green Technology—The centerpiece of the City's green building efforts is the Chicago Center for Green Technology. The Chicago Department of Environment transformed this property from a 17-acre brownfield full of construction debris, to the first municipal building to receive the LEED platinum rating. The 34,000 square foot center serves as an educational facility and rental space for organizations and businesses with an environmental commitment. Four 3,000-gallon cisterns capture stormwater that is used for watering the landscaping.

The site also features a green roof, bioswales, permeable paving, and a rain garden. Chicago Department of Environment models indicate that Green Tech's stormwater management features retain more than 50% of stormwater on site-for a three-inch storm, the site releases 85,000 gallons of stormwater to the sewer system instead of the expected 175,000 gallons.

The success of the Green Tech project spurred several other green building projects, including three new green libraries a new police station (to be monitored for a national case study), green renovations on a firehouse and police headquarters, and the Green Bungalow Initiative, a pilot project that aims to retrofit four of Chicago's historic bungalows with green technologies in an affordable way and monitor any corresponding energy savings. The Green Bungalow Initiative has shown an average energy savings for the green bungalows of 15% to 49% thus far.

Toward a comprehensive environmental action agenda: Developing and measuring performance goals and metrics

As Chicago's green infrastructure programs have matured, performance metrics have been added that serve to evaluate Chicago's green initiatives and promote implementation of sustainable technologies.

In 2005, Chicago launched a comprehensive Environmental Action Agenda, which charts progress toward building a sustainable city in areas such as fleets, green construction and operations, and energy efficiency and renewable energy. The aggressive goal of rethinking everything that the city does from an environmental perspective has required innovative partnerships with Chicago's universities and colleges as well as new programs to engage citizens.

The Environmental Action Agenda commits the City to a wide range of environmental initiatives with the goals of improving the quality of life in Chicago neighborhoods, conserving and protecting the City's natural resources, and, through the City's leadership and example, encouraging more Chicagoans to make environmentally conscious and economically-beneficial decisions in their homes and businesses. The initiatives are about much more than doing the "right thing" for the environment; they are also about improving the bottom line. They are intended to help the City stretch taxpayer funds during tight budgetary times, help residents save money on energy costs, and increase property values.

The agenda sets specific, measurable goals in the following areas:

  • Energy and green building in the public and private sectors
  • Transportation and mobility, encompassing City fleets, airports, transit and bicycle infrastructure
  • Infrastructure and resource management, including sustainable infrastructure, water resources, waste and recycling, and procurement
  • Education and outreach

The agenda is intended to be renewed and reviewed annually. A "report card" summarizes progress made during the previous year. Major water resources initiatives for 2006 and beyond include Initiatives 1 and 2 (City of Chicago, 2006):

Initiative 1: Pilot and implement "sustainable street" technologies on City streets

  • Commence design of a Sustainable Streets Pilot Initiative on Cermak Road and Blue Island Avenue, incorporating numerous green elements in the streetscapes including permeable and reflective paving, native plantings, bioswales, rain gardens and tree filters, stormwater and graywater irrigation, energy efficient lighting and solar-powered "pay and display" parking meter boxes.

Initiative 2: Expand stormwater management best practices

  • Continue to expand the Green Alley pilot program, (described above) which calls for rebuilding alleys with porous paving materials, testing five new prototypes, and conducting environmental outreach to neighboring residents. Apply these tested technologies to future alley construction projects.
  • Design and install a bio-retention pond in a roadway reconstruction project in order to incorporate and test natural stormwater treatment methods. Include a minimum of 15 infiltration basin treatment structures in roadway designs to reduce harmful particulates in stormwater.
  • Incorporate permeable pavement into on-street parking lanes in up to three projects spanning a total of 10 blocks.
  • Preserve up to five acres of wetlands on property adjacent to Chicago Department of Transportation construction projects.

Incentives for implementation, and rewards and recognition for those who "get it right"

The City has learned that implementation within the private sector is fostered through the use of incentives and rewards or recognition. While the City published a draft Stormwater Ordinance in 2007, which will require implementation of various measures, it has chosen to encourage voluntary participation by making it easy for private developers to "do the right thing," and by showcasing the work of private citizens and organizations.

Municipal buildings go green—One of the major drivers in encouraging sustainable building and site practices within the City is a requirement that all new City and County buildings register for LEED certification under the U.S. Green Building Council in Washington, D.C. As a result, the local design and construction community at large is getting a lot of experience on LEED projects. This experience is directly transferable to private development projects. In 2005, 22 new city buildings, including fire stations, schools and libraries, registered for LEED certification. For 2006, Chicago has committed to building all of its new buildings at a minimum LEED silver level with a target of gold.

The Green Permit Program—Initiated in April 2005, this program has proven attractive to many developers as it speeds up the permitting process. Under the Green Permit Program, a green building adviser reviews design plans under an aggressive schedule long before a permit application is submitted. "There's one point of contact with intimate knowledge about the project to help speed up the permit process," the program director says. "We handle fewer projects and keep them moving."

Projects going through the Green Permit Program receive benefits based on their "level of green". Tier I commercial projects are designed to be LEED certified. Tier II projects must obtain LEED silver rating. At this level, outside consultant review fees, which range from $5,000 to $50,000, are waived. Tier III projects must earn LEED gold. The goal for a Tier III project is to issue a permit in three weeks for a small project such as a 12-unit condo building.

"The goal is to cut the time in half. The incentive is saving time. And, if they qualify for second level, it's also the money with the consultant fee being waived." Private developers are most interested in the timesaving because they can pay less interest on their construction loans by completing the building faster and getting it sold.

By the end of 2005, 19 green permits were issued; so far this year, 32 such permits have been issued. The program's director estimated that about 50 would be issued in 2006, which exceeds the city's goal of 40.

Mayor Daley's GreenWorks Awards—These awards promote a green city by recognizing businesses, non-profits, schools and government agencies whose buildings, practices, and products or services are environmentally responsible. The GreenWorks Awards are presented bi-annually in three categories: Green Buildings, Green Practices, and Green Products. The Green Buildings category recognizes capital improvement projects that incorporate green building principles such as energy efficiency, renewable energy, stormwater management, and responsible materials.

Innovative strategies for bringing these ideas to the community

Most communities have implemented a public outreach campaign that promotes sustainable stormwater management through various media outlets and interpretive features, such as stormdrain stenciling campaigns. One of the more innovative concepts is Chicago's Greencorps program, operated through the Department of the Environment, which works with over 60 community groups each year. Greencorps provides horticultural expertise, physical assistance and a variety of plant and garden materials, such as rain barrels, cedar benches and compost. Greencorps also offers instruction in creating rain gardens and disconnecting downspouts, making these ideas accessible to residential homeowners. In addition, Greencorps Chicago is installing community gardens that include native plants and plants that require less watering, thereby increasing retain and use of stormwater onsite.

Additional Information:

Chicago Department of Environment: Water Quality and Stormwater Management


Chicago's Water Agenda, City of Chicago, Department of the Environment, 2003.

A Guide to Stormwater Best Management Practices. City of Chicago, Department of the Environment, 2004.

Environmental Action Agenda: Building the Sustainable City, City of Chicago, Department of the Environment, 2006.

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