United States River Flow Dataset

What this looks like

One real series from the dataset, and real rows from the head of its published extract. Neither is a mock-up: the rows below are the same rows, unchanged, that are in the file you would download.

Mean river flow at Mississippi River at Clinton, IA

The longest single series this dataset holds — 152 annual values, one of 1,750. The dataset is not this chart.

Drawn to show the shape and resolution of what the dataset contains, not to make a point about Mississippi River at Clinton, IA. Gaps are breaks, never interpolated.

View the data behind this chart

Underlying data
Period	Mississippi River at Clinton, IA (m³/s)
1874	1,441
1875	1,564
1876	1,939
1877	1,273
1878	1,229
1879	1,156
1880	1,767
1881	2,438
1882	2,027
1883	1,754
1884	1,881
1885	1,642
1886	1,405
1887	1,223
1888	1,922
1889	929
1890	1,341
1891	1,033
1892	1,728
1893	1,461
1894	1,222
1895	830
1896	1,183
1897	1,592
1898	998
1899	1,420
1900	1,391
1901	1,181
1902	1,222
1903	2,149
1904	1,547
1905	1,919
1906	1,999
1907	1,746
1908	1,444
1909	1,396
1910	847
1911	1,009
1912	1,254
1913	1,174
1914	1,178
1915	1,468
1916	1,826
1917	1,321
1918	1,127
1919	1,571
1920	1,542
1921	1,045
1922	1,282
1923	889
1924	1,091
1925	874
1926	1,137
1927	1,451
1928	1,598
1929	1,349
1930	891
1931	691
1932	916
1933	848
1934	671
1935	1,129
1936	1,000
1937	945
1938	1,582
1939	1,105
1940	864
1941	1,408
1942	1,502
1943	1,624
1944	1,470
1945	1,538
1946	1,402
1947	1,339
1948	959
1949	864
1950	1,271
1951	1,852
1952	1,642
1953	1,455
1954	1,409
1955	1,015
1956	991
1957	1,054
1958	755
1959	1,037
1960	1,343
1961	1,084
1962	1,452
1963	922
1964	799
1965	1,878
1966	1,355
1967	1,275
1968	1,377
1969	1,573
1970	1,145
1971	1,459
1972	1,732
1973	1,928
1974	1,365
1975	1,472
1976	978
1977	802
1978	1,374
1979	1,745
1980	1,199
1981	1,254
1982	1,687
1983	1,878
1984	1,812
1985	1,747
1986	2,268
1987	1,037
1988	753
1989	869
1990	1,294
1991	1,811
1992	1,665
1993	2,619
1994	1,731
1995	1,780
1996	1,724
1997	1,822
1998	1,597
1999	1,659
2000	1,307
2001	1,923
2002	1,751
2003	1,211
2004	1,503
2005	1,385
2006	1,233
2007	1,381
2008	1,657
2009	1,262
2010	2,055
2011	2,170
2012	1,142
2013	1,728
2014	2,040
2015	1,481
2016	2,132
2017	2,216
2018	2,301
2019	3,214
2020	2,109
2021	1,294
2022	1,489
2023	1,551
2024	1,698
2025	1,401

Sample rows

12 of 646,106 rows Taken from the start of observations-river-flow-usgs-nwis.csv. These are sample rows, not the dataset.

Sample rows from the United States River Flow Dataset extract
`metric_id`	`subject_id`	`subject_kind`	`value`	`censored`	`censor_operator`	`censor_threshold`	`censor_limit`	`censor_reported`	`unit`	`period_start`	`period_end`	`period_kind`	`basis`	`confidence`	`source_id`	`source_ref`	`qualifier`	`superseded`	`retrieved`
catchment-area	gauge-usgs-01010500	geography	6980.017957	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01010500, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01011000	geography	3180.505399	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01011000, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01013500	geography	2253.289656	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01013500, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01014000	geography	14700.772514	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01014000, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01018500	geography	1061.895125	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01018500, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01019000	geography	580.157337	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01019000, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01020000	geography	3405.834365	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01020000, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01021500	geography	1186.214555	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01021500, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01023000	geography	383.31824	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01023000, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01029500	geography	2812.727088	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01029500, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01031500	geography	766.636481	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01031500, contributing drainage area	contributing area	—	2026-10-01
catchment-area	gauge-usgs-01033000	geography	841.746136	—	—	—	—	—	km²	2026-08-31	—	instant	reported	high	usgs-nwis	USGS site 01033000, contributing drainage area	contributing area	—	2026-10-01

Download these rows as CSV — the same twelve, with the column header, for testing a loader before committing to the full file.

Methodology

Annual mean discharge as published by the USGS statistics service, computed by USGS from its own quality-controlled daily record. Hydrionis does not recompute the mean; it converts cubic feet per second to cubic metres per second — a foot being exactly 0.3048 m, the conversion is exact — and records the publisher’s unit alongside so a value can be checked against the source. Sites are selected per state because the USGS site service does not accept a national query, and a site is kept only where the published statistics themselves span fifty years, which is a stricter test than the period of record advertised in the site listing.

What this dataset cannot tell you

Coverage

Subjects	United States streamgauges opening before 1930 with 50+ years of published statistics — 1,750 held
Period	1874–2025
Units	m³/s
Update cadence	Annually
Identifier	`us-river-flow` v1.0.0

Fields

Data dictionary →

Every metric this dataset carries, with the unit it is stored in and the geography level it is reported at. Full definitions are in the data dictionary.

Identifier	Field	Unit	Reported at
`river-flow-mean`	Mean river flow Average volumetric discharge past a gauging station over a stated period.	m³/s	river-gauge

Rights and access

Licence position

Open. Derivative use true; redistribution true; commercial reuse true.

Applies to material authored by US federal agencies. Third-party material carried within a federal product may be separately protected.

Permitted uses

Public display
Derived analysis
API delivery
Bulk download
Commercial use

Available to: Public, Developer, Research, Professional, Enterprise. These follow from the rights of the contributing publishers, not from a Hydrionis pricing decision — no access tier can widen what a publisher withheld.

Contributing sources

United States Geological Survey — National Water Information System (US Government work — public domain)

Attribution and citation

Cite and reuse →

Two different obligations, deliberately kept apart. One is a condition of somebody else's licence; the other is a request Hydrionis has no standing to enforce.

Suggested citation for Hydrionis

Hydrionis (2026), United States River Flow Dataset, version 1.0.0, accessed 2026-10-05, hydrionis.com/data/datasets/us-river-flow/

Cite Hydrionis where you rely on the compilation, the normalisation, the eligibility judgements or a chart. Where you use an unmodified published value, the publisher’s attribution is the one that is required; crediting Hydrionis as well is welcome and is not something Hydrionis can require of you.

Recommended, not required. Hydrionis does not claim rights over unmodified public data it relayed, and doing arithmetic on somebody else’s measurements does not make them Hydrionis’s. Cite the version and the access date: United States River Flow Dataset changes as publishers release and as methods are revised, and a citation without both cannot be checked later. Full guidance is on cite and reuse.

None of the contributing licences requires attribution. Crediting the publishers is still good practice and they are listed above.

Changelog

Version 1.0.0 — 2026-08-24

First release, and the first Hydrionis dataset outside the United Kingdom drawn from station-level measurement.

Additions

Annual mean flow for 1,751 long-record United States gauges.

Use this data

Download river-flow observations from USGS (646,106 rows) (CSV)
Machine-readable JSON /api/v1/datasets/us-river-flow.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

Every bulk extract ships with a companion metadata file carrying this dataset’s version, its sources, their licences, the attribution you are required to give and the suggested citation — so the terms travel with the file rather than staying on this page.

About this data

The fields a professional user needs to judge whether this is fit for a particular purpose. Deliberately not a score.

About this data

Everything below is a property of the data rather than a rating of it. There is deliberately no single confidence score: how much a gap matters depends on what you are about to do with the series, and only you know that.

Source	United States Geological Survey — National Water Information System · US Government work — public domain
How the values came to exist	Mixed across the series — the basis is recorded on every individual value.
Period held	1874–2025
Known gaps	Annual means only. Monthly means are published by the same service and are not collected; seasonal behaviour cannot be read from this dataset. Flow is a property of a gauge on a reach, not of a river, and is affected by upstream regulation, diversion and abstraction. Many long US records sit below major dams built during the record. The mean is USGS’s own, computed on its water year and methodology. It is not directly comparable with the England series, which Hydrionis computes itself from daily values on calendar years.
Continuity	Version 1.0.0, released 2026-08-24. 1 recorded version; breaking changes and corrections are listed in the changelog above.
Last read from the publisher	2026-10-01 · publisher updates annually
Redistribution	Permitted by the upstream licences
Commercial reuse	Permitted by the upstream licences. No Hydrionis access tier can widen this.
Methodology	How this was produced