The Prevalence and Cost of Urban Flooding

Investigating Cook County, Illinois as a case study, this report assesses the financial cost related to urban flooding between 2007-2011. Urban flooding as described here can include overflow from rivers and streams, sewage pipe backups, water seepage through building walls and floors, and stormwater accumulation. Cook County is primarily urban and densely populated with the City of Chicago making up approximately 54% of the population. The study found that urban flooding is chronic and often repetitive in this county, costing a total of $773 million in insurance claims over five years. It was also found that there is no correlation between damage payouts and floodplains, noting that the National Flood Insurance Program only accounted for 8% of payouts.

The study relied on insurance claims information in Cook County over the five-year period. These data likely underrepresents flooding in the region since they do not capture people who did not make claims because they are uninsured or chose not to, or any costs that were not covered by claims. The report also drew on an online survey of 115 self-selecting Cook County residents that suffered from flooding, for qualitative feedback. 73% of the online survey respondents estimate that they had flooded three or more times in the last five years, and 20% have flooded 10 or more times.

In addition to the findings related to the financial cost of flooding, the researchers found that many homeowners had invested in measures to prevent future flooding (e.g. downspout disconnection, rain gardens, and pumps). However, only 6% of survey respondents believed that the investment had solved their problem.


This research is part of the Center for Neighborhood Technology’s Smart Water for Smart Regions initiative dedicated to inventive solutions and advocacy focused on water supply and stormwater in the Great Lakes states. Visit for more information.



Publication Date: May 2014

Related Organizations:

  • Center for Neighborhood Technology
  • RainReady


Resource Category:

Resource Types:

  • Assessment
  • Case study

States Affected:


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