Planning November 2017

Flood Ready

Managing urban flooding takes data, tools, and a grassroots approach.

By Molly Oshun

Flooding is the costliest and most common type of natural disaster in the U.S. According to the Federal Emergency Management Agency, from 2006 to 2015, federal insurance claims averaged $1.9 billion a year annually. In September, FEMA was anticipating around $11 billion in claims from Hurricane Harvey alone, while Hurricane Irma payouts were expected to be even higher. And with global climate change, more flooding is expected: The National Climate Assessment predicts an increase in extreme precipitation, heavy downpours, sea-level rise, and hurricane frequency, which is expected to increase flooding along coasts and rivers.

Behind the specter of these major disasters lurks another hazard: urban flooding. Distinct from riverine and coastal flooding, urban flooding occurs when rain overwhelms drainage systems and waterways, making its way into basements, yards, and streets. It leads to multibillion-dollar damages but often lacks regulatory oversight and is far less studied. Urban flooding also disproportionately affects low-income and minority communities. But a handful of close-in, mostly African American and Latino suburbs just south of Chicago are taking action. The lessons from those efforts are readily transferable, and show how planners can use data, tools, and residents' knowledge to plan for smarter, more innovative communities.

Map of the Calumet Corridor by Chuck Burke; Source: The Center for Neighborhood Technology

In February 2016 Cook County hired RainReady, an initiative of the Center for Neighborhood Technology, a research and advocacy group based in Chicago, to implement a new approach to stormwater management along the Calumet Corridor. It focused on six of the 11 communities severely impacted by record-level flooding in April 2013, when former President Barack Obama declared a federal disaster.

While those floods captured headlines, urban flooding affects Calumet residents multiple times every spring and summer. The six communities — Robbins, Blue Island, Calumet Park, Riverdale, Dolton, and Calumet City, with a total population of around 103,000 — face a mix of flooding risks common to the area, including overbanking from waterways, sewer backup into basements, water seepage into building foundations, and pooling in streets and yards.

In Calumet Park, basements and streets can overflow with water after just a two-year storm. In Dolton, children sometimes pile off the school bus onto stacked wooden pallets to avoid the water-soaked street. In Robbins, sections of the community lack any storm sewer system. Chronic flooding has led many residents to feel hopeless about solutions. While some home owners have given up on their basements, others dutifully pull out the bleach and rubber boots after each big rain.

Backyard flooding in Midlothian, Illinois, on July 12, 2014. This property sits on the footprint of a prehistoric glacial lake, and locals call it "Lake Midlothian" when the waters rise. Photo courtesy the Center for Neighborhood Technology.

From 2007 to 2011, 12,720 insurance claims were paid out in the zip codes that make up the Calumet Corridor, an amount totaling around $33 million. In RainReady's earlier analysis of flood damage claims in Cook County, 67 percent of the most impacted zip codes were found to earn below the county's median household income. The Calumet Corridor is representative of the groups typically hit hardest by urban flooding: minority, low- to moderate-income communities that have high rates of unemployment and vacant properties.

Dolton Steering Committee Chair Bobby Evans gives CNT staff a tour of flooding in his neighborhood. Photo courtesy the Center for Neighborhood Technology.

There are several reasons low- to moderate-income communities of color are disproportionately impacted by flooding. Limited household income and poor access to information on coste effective solutions affect residents' ability to pay for flood-prevention measures in their homes. At the municipal scale, strained public coffers and overstretched staff impede innovative infrastructure upgrades. Affecting both of those groups is the gap in grassroots flooding knowledge, as well as mistrust of government, which undermines collaboration between stakeholders. Historic settlement patterns have a big impact, too: Redlining in the 1920s and 1930s in Chicago forced many black families to buy homes in low-lying, flood-prone areas.

RainReady: Four Main Goals

  1. Establish a shared understanding of flood risk.
  2. Achieve consensus on priority solutions that provide multiple benefits to the community.
  3. Provide municipal and community leaders with a clear roadmap for plan implementation.
  4. Pursue plan implementation concurrent to plan development by advancing priority projects.

The plan in action

Over the course of 15 months, the project team developed the RainReady Calumet Corridor Plan to help these residents. It addresses chronic urban flooding in an area plagued by vacant properties and decommissioned industrial land.

The RainReady approach applies a unique combination of grassroots organizing and analytic innovation. The program was previously piloted in Midlothian — also in Cook County — and Chatham, a south side Chicago neighborhood. The planning process was broken into three distinct phases (a fourth phase, Monitoring & Adaptation, will be led by municipal partners and regional agencies).

PHASE 1: Risk and Opportunity Assessment

Within the Calumet Corridor, the scope and severity of flood risk was largely unknown. The process began with an assessment of urban flood risks, community concerns, and opportunities for solutions.

Whereas FEMA's National Flood Insurance Program designates and regulates flood hazard areas in low-lying areas near waterways, the location of urban flooding is more difficult to predict. It can be highly localized, resulting from poor drainage, or caused by cracked, clogged, or undersized infrastructure. It can also change with the landscape, as when a new parking lot is added to an already overtaxed drainage network. Still, planners have tools and data to identify urban flood risks and conduct opportunity assessments.

Robbins residents discuss flood risk and opportunity with U.S. Army Corps of Engineers staff at a RainReady community meeting. Photo courtesy the Center for Neighborhood Technology.

INSURANCE CLAIMS DATA. In RainReady's 2013 study of flood insurance claims and a survey of flood victims, it found more than $773 million in damages paid out from 2007 to 2011 across Cook County. When considering private insurance, disaster recovery, and FEMA flood insurance, there was no correlation between the location of flooding and FEMA-designated flood hazard areas.

Moreover, the project team found that flooding is repetitive: 70 percent of survey respondents estimate three or more floods in five years; 20 percent flooded 10 or more times.

A study from the Illinois Department of Natural Resources backs up the data on urban flooding: It revealed that, statewide, 92 percent of flood damage payouts occur outside of FEMA's mapped flood hazard areas.

Despite this trove of data, insurance claims are likely a conservative estimate of the true extent of flooding. Not all flood victims carry insurance, and not every policyholder files a claim after each flood.

COMMUNITY-REPORTED RISK. To develop a more complete picture of urban flood risk, the team prioritized community-reported incidents of flooding. By investing in relationships with community members, it was able to uncover flooding that might have been missed by hydraulic and hydrologic modeling, insurance claims data, or information provided by public works officials. While RainReady's community engagement approach is both time and labor intensive, it improves the plan document and builds long-term capacity for its implementation.

Building community relationships can be slow and complex. Flood victims can be reticent to share their stories for fear of impact on property values. Alternatively, years of inaction on flooding may leave them cynical toward government-led solutions.

To build local partnerships, RainReady employed a full-time outreach associate local to the project area. Under her leadership, a robust and ongoing community outreach effort was launched. The team participated in community events, partnered with local stakeholders, and hosted a series of interactive meetings. In each instance, the RainReady team was clear about the opportunities and limitations inherent to the planning process. Since the plan would not deliver relief for several years, the team provided do-it-yourself information upfront to help home owners reduce risk in the short term.


Over the course of nine months, this part of the process included:

1 Regional Technical Advisory Committee

6 educational workshops

6 new Community Steering Committees

7 community meetings

50 local and regional stakeholder meetings

100 reviews of existing plans, programs, and policies

584 resident survey responses

2,100 engagements with residents through door-to-door outreach, event tabling, or community presentations

LIDAR-BASED ANALYSIS. RainReady employed a new analytic method for delineating urban watersheds and siting green infrastructure using LIDAR data. The team adapted this method in partnership with the U.S. Army Corps of Engineers from an approach pioneered by the region's MPO, the Chicago Metropolitan Agency for Planning.

CMAP first developed this methodology to integrate stormwater management into decisions about land use and development in the Chicago region. The methodology established a framework to prioritize areas of a community that would benefit from green infrastructure and land-use intervention, illustrate how green infrastructure could be applied in those priority areas, and identify potential locations for further analysis.

The project team augmented and refined this approach in its custom planning tool, the RainReady Optimizer.

OPPORTUNITY ASSESSMENT. The team created a geocoded database of recommendations from more than 100 previous and ongoing planning efforts that transportation, economic development, cargo-oriented development, and conservation plans — as well as projects identified verbally in stakeholder meetings. The goal was to identify opportunities for green infrastructure that could reduce flood risk while helping the community achieve other goals, like beautification and community development.

From A Citizen's Guide to a RainReady Dolton, a rendering showing how sidewalk improvements, bioswales, and tree plantings could alleviate flooding in bad weather and enhance the neighborhood year-round. Rendering courtesy the Center for Neighborhood Technology.

RAINREADY OPTIMIZER. This tool helped to analyze flood risk and the potential impact of green infrastructure solutions. The Optimizer does several things, including identifying urban catchments, giving each a flood-risk score; providing ancillary map layers with other data related to hydrology, environmental conditions, transportation infrastructure, political jurisdictions, and economic development; and enabling the rapid, iterative testing of green infrastructure solution alternatives.

To calculate the flood-risk score, the Optimizer adapts CMAP's original approach with the addition of several community-derived data sets. The score aggregates diverse indicators of flood risk, including percentage of impervious land, depression areas, known problem areas identified by local and regional government, and community-reported data. Additionally, the tool incorporates the geocoded opportunity database.

The addition of CNT's Green Values Stormwater Calculator enables rapid testing of green infrastructure solutions applied spatially across the urban catchment. The result is a low-cost decision-support tool for siting green infrastructure in a way that is hydrologically sound and that maximizes the co-benefits of green infrastructure.

For example, the local council of governments has spent years advocating for the redevelopment of an old granary in Riverdale. Locally, it was understood that runoff from the vacant parcel contributes to flooding in an adjacent neighborhood. However, without a hydrologic study, no public stormwater funding could be made available to rehabilitate the site for a new use. Using the RainReady Optimizer, CNT was able to demonstrate the hydrologic connectivity of the two sites, thereby bringing in new partners and funding.

First RainReady Community: Midlothian

RainReady piloted its community planning process with the U.S. Army Corps of Engineers in Midlothian, Illinois (pop. 14,699), in 2015. Since adopting the RainReady Midlothian Plan in January 2016, residents and municipal leaders have partnered to secure more than $9.6 million in stormwater planning and construction investment. The progress made by Midlothian leaders demonstrates the value of a grassroots process designed to create new connections between local and regional groups. Key projects in progress include:

Landscaping and engineered conveyance improvements to Natalie Creek, a nuisance waterway that will be turned into a beautiful community amenity with a regional trail, improved lighting, and habitat restoration.

A corridor study led by the Chicago Metropolitan Agency for Planning of the main mixed use thoroughfare, IL-83, bringing together green infrastructure, active transportation improvements, and placemaking features.

The passage of Cook County's first municipal complete streets ordinance inclusive of stormwater management features, made possible with technical assistance from the Active Transportation Alliance.

An audit of the Midlothian Building and Zoning Department to ensure compliance with the National Flood Insurance Program and to pursue participation in FEMA's Community Rating System.

PHASE 2: Solution Mapping

Next, it was time to ground-truth the assessment. The project team produced Community Resilience Snapshots, which it shared at community and village board meetings.

CNT gathered additional data to improve and refine the RainReady Optimizer, incorporating resident input and mapping priority areas for beautification efforts using green infrastructure. Throughout, it engaged in an iterative process of solution development, refinement, and prioritization.

The team also hosted educational workshops to build local capacity among residents and municipal employees, helped to identify financing opportunities, and gave guidance on partnering to obtain local funds and outside grants.

Each community had a resident steering committee, which established mission and vision statements, goals, and strategies. A regional technical advisory committee made up of stormwater experts was also established. These committees were a resource of immeasurable value, guiding, correcting, and taking ownership of the plan recommendations developed by the RainReady team.

CNT's RainReady Resilience Planning Tool (Dolton, Illinois)

PHASE 3: Plan Development and Implementation Support

In Phase 3, the team compiled its vast Risk and Opportunity Assessment into the RainReady Calumet Corridor Plan. As of September 2017, the plan had been adopted by Calumet City, Calumet Park, and Dolton, and public commitments to implementation have been made by leaders from Cook County, the Metropolitan Water Reclamation District, and each municipality.

With the goal of concurrent plan implementation in mind, CNT used the RainReady Optimizer to develop more detailed site plans for 22 priority projects, which are moving forward. Notable priority projects include:

A GREEN STORMWATER PARK called the Dolton-South Holland Basin, designed by the U.S. Army Corps of Engineers, will reduce yard and street flooding and create a beautiful amenity in a low-income neighborhood in Dolton.

A COUNTY-LED RESIDENTIAL RETROFIT PROGRAM will help low-income home owners across the Calumet Corridor reduce their risk of future flooding through green and gray infrastructure improvements.

AN INITIATIVE TO REHABILITATE WETLANDS adjacent to a currently vacant industrial property in Riverdale could reduce residential flooding, improve water quality, and incentivize redevelopment of a key job center.

The six resulting RainReady Plans set a coordinated path forward for flood resilience that prioritizes investment in green infrastructure to bring wider and more cost-effective benefits to the community when compared to large-scale, engineered approaches.

The plan also recommends action at multiple scales, combining individual property upgrades with actions in public spaces. Most critically, the plan reflects the collaborative vision of residents, public officials, and regional partners.

By lifting up grassroots organizing and new analytic models, CNT's RainReady program is sowing the seeds of resilience in some of Chicagoland's most vulnerable populations.

Molly Oshun directed the RainReady Community program at the Center for Neighborhood Technology from 2015 to 2017. She is a certified conflict mediator, Stanford engineer, and committed community organizer currently on creative sabbatical, traveling to wild places throughout the U.S.


RainReady information, guidance, and fact sheets:

National Climate Assessment: