Statistical summaries of selected Iowa streamflow data through September 2013

Open-File Report 2015-1214
Prepared in cooperation with the Iowa Department of Transportation, the Iowa Highway Research Board (Iowa DOT Research Project TR-669), and the U.S. Army Corps of Engineers
By: , and 



Statistical summaries of streamflow data collected at 184 streamgages in Iowa are presented in this report. All streamgages included for analysis have at least 10 years of continuous record collected before or through September 2013. This report is an update to two previously published reports that presented statistical summaries of selected Iowa streamflow data through September 1988 and September 1996. The statistical summaries include (1) monthly and annual flow durations, (2) annual exceedance probabilities of instantaneous peak discharges (flood frequencies), (3) annual exceedance probabilities of high discharges, and (4) annual nonexceedance probabilities of low discharges and seasonal low discharges. Also presented for each streamgage are graphs of the annual mean discharges, mean annual mean discharges, 50-percent annual flow-duration discharges (median flows), harmonic mean flows, mean daily mean discharges, and flow-duration curves. Two sets of statistical summaries are presented for each streamgage, which include (1) long-term statistics for the entire period of streamflow record and (2) recent-term statistics for or during the 30-year period of record from 1984 to 2013. The recent-term statistics are only calculated for streamgages with streamflow records pre-dating the 1984 water year and with at least 10 years of record during 1984–2013. The streamflow statistics in this report are not adjusted for the effects of water use; although some of this water is used consumptively, most of it is returned to the streams.

Suggested Citation

Eash, D.A., O’Shea, P.S., Weber, J.R., Nguyen, K.T., Montgomery, N.L., and Simonson, A.J., 2015, Statistical summaries of selected Iowa streamflow data through September 2013: U.S. Geological Survey Open-File Report 2015–1214, 18 p.,

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • U.S. Geological Survey Streamgage Network in Iowa
  • Explanation of Streamgage Summaries and Streamflow Statistics
  • Data Considerations
  • Summary
  • References Cited

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Statistical summaries of selected Iowa streamflow data through September 2013
Series title Open-File Report
Series number 2015-1214
DOI 10.3133/ofr20151214
Year Published 2015
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Iowa Water Science Center
Description Report: vii, 18 p.; Table; Companion File
Time Range Start 1984-01-01
Country United States
State Iowa
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional metadata about this publication, not found in other parts of the page is in this table