Streamflow - Water Year 2017

Fact Sheet 2018-3056
By: , and 



The maps and graphs in this summary describe national streamflow conditions for water year 2017 (October 1, 2016, to September 30, 2017) in the context of streamflow ranks relative to the 88-year period of 1930–2017, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey (USGS) National Streamflow Network (U.S. Geological Survey, 2018a). The period of 1930–2017 was used because the number of streamgages before 1930 was too small to provide representative data for computing statistics for most regions of the country.

In the summary, reference is made to the term “runoff,” which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a specified period was uniformly distributed on it. The value of runoff quantifies the magnitude of water flowing through the Nation’s rivers and streams in  measurement units that can be compared from one area to another. In this summary, runoff for a specified period and geographic area is computed from all streamgages with  complete record in the geographic area.

In all the graphics, a rank of 1 indicates the highest annual flow of all years analyzed and 88 indicates the lowest annual flow of all years. Rankings of streamflow are grouped  into much below normal, below normal, normal, above normal, and much above normal based on percentiles of flow (less than 10 percent, 10–24 percent, 25–75 percent, 76–90 percent, and greater than 90 percent, respectively; U.S. Geological Survey, 2018b). States or water-resources regions are presented in the text in order of ranking; a highest or lowest rank is not shown when there are ties in the rankings. Some of the data used to produce the maps and graphs are provisional and subject to change.

Suggested Citation

Jian, X., Wolock, D.M., Brady, S.J., and Lins, H.F., 2018, Streamflow—Water year 2017: U.S. Geological Survey Fact Sheet 2018–3056, 6 p.,

ISSN: 2327-6932 (online)

Table of Contents

  • Introduction
  • National Overview
  • Regional Patterns
  • Seasonal Characteristics
  • High and Low Flows
  • Additional Information
  • References
Publication type Report
Publication Subtype USGS Numbered Series
Title Streamflow - Water Year 2017
Series title Fact Sheet
Series number 2018-3056
DOI 10.3133/fs20183056
Year Published 2018
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Kansas Water Science Center
Description 6 p.
Country United States
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details