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Floods of June 2024 in Northwestern Iowa

Open-File Report 2026-1066
Prepared in cooperation with the Iowa Department of Transportation
By:  and 
https://doi.org/10.3133/ofr20261066

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Abstract

Following a heavy, multiday rainfall event that took place between June 20 and June 22, 2024, widespread flooding occurred in parts of northwestern Iowa. Ten U.S. Geological Survey (USGS) streamgages with periods of record ranging from 56 to 99 years in length experienced new peaks of record, three of which were more than double the previous peak-of-record: 06483500 (Rock River near Rock Valley, Iowa), 06605850 (Little Sioux River at Linn Grove, Iowa), and 06606600 (Little Sioux River at Correctionville, Iowa). A Presidential declaration of a major disaster for the State of Iowa was approved on June 24, 2024, and the cost of the flooding is estimated at over $310 million. The severity of this flooding prompted the USGS, in cooperation with the Iowa Department of Transportation, to summarize the meteorological and hydrological conditions preceding the flooding, compile estimates of the magnitude of peak flows resulting from the flooding, and update estimates of peak-flow frequency for selected USGS streamgages. Of the 33 streamgages analyzed, a peak streamflow occurred that corresponded to an annual exceedance probability of less than 4 percent at 13 streamgages, an annual exceedance probability of less than 1 percent at 6 streamgages, and an annual exceedance probability of less than 0.2 percent at 1 streamgage.

Suggested Citation

Marti, M.K., and O’Shea, P.S., 2026, Floods of June 2024 in northwestern Iowa: U.S. Geological Survey Open-File Report 2026–1066, 16 p., https://doi.org/10.3133/ofr20261066.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Purpose and Scope
  • U.S. Geological Survey Response to Flood
  • Changes in Historical Peak Streamflows
  • Summary
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Floods of June 2024 in northwestern Iowa
Series title Open-File Report
Series number 2026-1066
DOI 10.3133/ofr20261066
Publication Date March 05, 2026
Year Published 2026
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Central Midwest Water Science Center
Description Report: vi, 16 p.; Data Release
Country United States
State Iowa
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Additional publication details