Heavy rainstorms in Chicago: Increasing frequency, altered impacts, and future implications

Stanley A. Changnon, Nancy E. Westcott

Research output: Contribution to journalArticlepeer-review


Operations of a dense raingage network in the Chicago area since 1989 provided data to assess the temporal and spatial distributions of heavy rainstorms. The 12-year average was 4.4 storms per year, 40 percent more than in the 1948 to 1980 period, reflecting an ongoing Midwestern increase in heavy rains. The total rainfall from the 53 heavy rainstorms maximized over the city, reflecting previous observations that the influence of the city and Lake Michigan on the atmosphere causes an increase in heavy rains. Impacts from the record high number of eight storms in 2001 revealed that efforts to control flooding including the Deep Tunnel system, had reduced street and basement flooding in the moderate intensity storms, but the two most intense storms, each with 100-year rainfall values, led to excessive flooding and a need to release flood waters into Lake Michigan. Results suggest continuing increases in the number of heavy rainstorms in future years, which has major implications for water managers in Chicago and elsewhere.

Original languageEnglish (US)
Pages (from-to)1467-1475
Number of pages9
JournalJournal of the American Water Resources Association
Issue number5
StatePublished - Oct 2002


  • Climatic fluctuations
  • Flooding impacts
  • Rainstorms
  • Stormwater management
  • Urban hydrology
  • Urban induced rainfall

ASJC Scopus subject areas

  • Ecology
  • Water Science and Technology
  • Earth-Surface Processes


Dive into the research topics of 'Heavy rainstorms in Chicago: Increasing frequency, altered impacts, and future implications'. Together they form a unique fingerprint.

Cite this