By Michelle Inouye
In the spring of 2013, a severe rainstorm in the Chicago area resulted in 3,300 City Services (311) calls from businesses and residents about basement and street flooding. The storm caused extensive damage to homes, businesses to shut down, and flooding at train stations and bus stops. This prompted immediate action by the Chicago Mayor’s Office, along with the planning, water management, transportation, and emergency management entities, to prioritize strategies and actions to reduce future stormwater impacts during peak storm events.
The increased frequency of intense storms has created a demand for more resilient stormwater management practices and flood mitigation projects in urban areas across the globe. In early 2017, the City of Chicago used grant funding to implement the Chicago Resilient Corridors Project, developing concentrated stormwater landscapes (green infrastructure) on city-owned vacant lots in flood-affected neighborhoods. Chicago’s West Side was selected as an implementation area, representative of the City’s urban landscape, with a variety of land-use types and home to diverse populations. Instead of capturing stormwater that only falls on-site, numerous corridor sites were established to collect and detain stormwater from streets and alleys to relieve sewer mains, mitigating wet basements for a greater number of households.
AECOM, a global infrastructure firm, assembled a multi-disciplinary team – including Hey and Associates, Inc., Quercus Consulting and Green Metro Planning LLC – who all partnered with the Department of Planning and Development (DPD) to create a visionary, efficient, technically rigorous, and inclusive community process. Ten sites on three transitional commercial corridors (Chicago Avenue, 16th Street and Ogden Avenue) on the City’s West Side were developed, using available data and resources to identify optimal locations for stormwater detention infrastructure, as well as frequent and effective community outreach that ensured social benefits for these neighborhoods.
Green Infrastructure Implementation
Each site used multiple techniques to capture stormwater runoff: permeable pavements used for the walks, plazas, and multi-purpose courts provided significant volume storage; native plantings framed spaces and created intimate places while reducing “urban heat island” and attracting pollinators; runnels and drainage swales became elevated water collection as an interactive design element; and bioretention systems became defining entry features meaningfully integrated within site.
To verify these designs, detailed hydrologic and hydraulic modeling scenarios were run using the city-wide InfoWorks sewer system model for six-month, and one-, two- and five-year storm events, with and without the stormwater landscape projects. The findings demonstrated that these projects are expected to store 506,000 gallons of stormwater and reduce runoff into the sewer system thereby reducing hydraulic grades across the sewer system and the likelihood of basement flooding. Sites with monitoring equipment installed have pole mounted rain gauge, solar panel and equipment boxes. A sensor that measures underground water levels is located in the underground storage and infiltration areas. Monitoring data functions on the same data platform as other city green infrastructure evaluation projects.
The City of Chicago is also working with an urban sensing project, the Array of Things (AoT), to monitor a range of environmental factors. Both the stormwater sensors and AoT nodes are uploaded to open data portals. This information provides insights into the benefits of the Resilient Corridors Project, creating a valuable feedback loop for continual improvement of subsequent planning and design efforts.
Active community engagement generated the programming for each site, which included passive gardens, active recreation areas and public plazas. As green infrastructure treatments have slightly more technical requirements than a typical community garden, a “Resilient Corridors Project Manual” was developed for the stewards, covering such components as site plans, volunteer tasks, resources and maintenance logs to facilitate long-term project success.
A Focus on Beneficial Developments
Here are examples of three sites that were developed on vacant land as part of the Resilient Corridors Project.
- Site 1a / 1b – The Kelly YMCA and its affiliated Franciscan Brothers are the community stewards for two sites on Chicago Avenue. Their ideas for augmenting the Y’s programming for children (a basketball court), seniors (accessible planters with large flex space), and its many volunteers (off-street parking) drove the site design in its entirety.
- Site 07 – This corner site crosses includes three parcels and will provide the community with a central gathering space for play time, concerts and cookouts. A local pharmacy, which has been a fixture on the block for more than 50 years, is serving as the steward.
- Site 10 – The Chicago Botanic Garden (CBG) is a community steward for a site on Ogden. The team’s engagement with CBG focused on ensuring the design itself and the material selection supported their very successful urban farming program through the development of large scale raised beds surrounded by fruit-bearing shrubs.
Positive Impact on Community
Early and active community outreach paired City initiatives with local investment and oversight. The process provided a platform for collaborative site programming and nurtured community stewards, who gained a deeper understanding of how these projects enhance their community’s resilience. The Chicago Resilient Corridors Project demonstrates the impact smart, integrated implementation of green infrastructure can have on livability through open space amenities that are visually attractive, expand community space and reduce flooding.
With construction completed in fall 2018, the Resilient Corridors Project has served as a springboard for the City’s broader green infrastructure program, which expands the model for stormwater capture with new partners. All team members worked firsthand with communities to design memorable spaces, both active and passive, and to strengthen the public realm. It also introduced a new city paradigm – to create resilient places with long-term community stewards – that can be replicated in other neighborhoods. Green infrastructure offers more than “just” stormwater management, it provides co-benefits such as improved physical and mental health for people using and living near the sites, and economic development opportunities. Any geography facing similar resilience issues can benefit from interdepartmental and regional collaboration and a robust community engagement model. By integrating the Resilient Corridors Project with other diverse strategies of scale, the City of Chicago can begin addressing its complex urban challenges with innovative solutions merging design and infrastructure.
Michelle Inouye is Associate Principal for Design + Planning at AECOM.