The monitoring network within this area

Hydrionis holds 344 values from 2 gauges within it. Discharge is a property of a gauge and its reach, not of this drainage area, so this page reports the network and its records rather than a single figure.

Gauges

344

Values held

1929–2026

Record spans

Gauges within the Obion huc8 subbasin

2 monitoring points, positioned as the publisher records them.

Flood peaks, as measured

This gauge's flood record, as measured. Unlike a daily mean it is the discharge at the moment the river was highest, which is the figure flood frequency analysis is built on.

Largest measured flow of each year at OBION RIVER AT OBION, TN

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1930–1990.

Published by the gauge's own operator from its sub-daily record; Hydrionis stores the figure rather than recomputing it. A year the gauge did not cover produces no value rather than a low one, and the gaps are stated below the chart. A peak is a property of this gauge and its reach: a larger flood upstream or downstream of it is not in this series.

What the shaded periods are (0 events)

Not shown on this chart

The 1976 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
The 2022 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Yorkshire drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cantareira water crisis, São Paulo — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cape Town Day Zero — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
European drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.

View the data behind this chart

Underlying data
Period	OBION RIVER AT OBION, TN (m³/s)
1930	1,331
1931	72.8
1932	960
1933	728
1935	1,317
1936	177
1937	2,818
1938	487
1939	691
1940	314
1941	67.1
1942	640
1943	640
1944	479
1945	821
1946	714
1947	493
1948	498
1949	493
1950	756
1951	1,051
1952	787
1953	739
1954	280
1955	538
1956	1,136
1957	711
1967	1,104
1968	957
1969	702
1970	1,082
1971	753
1972	430
1973	1,130
1974	1,096
1975	1,337
1976	736
1977	377
1978	470
1979	1,085
1981	793
1982	555
1983	1,195
1984	1,254
1986	518
1987	595
1989	1,354
1990	782

About this series

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	Measured
Period held	1930–1990
Completeness	78.7% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	5 separate periods inside 1930–1990 hold no value. The longest runs from 1958 to 1966 — 9 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1930 and is not continuous from it: 61 years separate the first value from the last, and 79% of the years between them are held. The span is not the record.
Last read from the publisher	2026-10-01
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

How much of the rain came back out

A discharge in cubic metres per second cannot be compared with anything: the larger number may only mean the larger catchment. Divided by the area draining to the gauge it becomes a depth of water over that land, which answers a question a reader already has — of the rain that fell here, how much came back out as river?

Water leaving the catchment above OBION RIVER AT HWY 51 NEAR OBION, TN, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1930–2025.

Show relevant events (1 event)Shading marks when something was recorded, not what caused the line.

Computed by Hydrionis from the published annual mean flow and the catchment area the station's own publisher states. It is not a water balance: the difference between rainfall and runoff is not evaporation alone but also change in groundwater storage, water abstracted and taken elsewhere, and water imported by transfer schemes — which is why a catchment can yield more runoff than the rain that fell on it without anything being measured wrongly. A different area figure rescales every value here by the ratio between them.

What the shaded periods are (1 event)

A shaded period marks when something was recorded, not what caused the shape of the line. Where the two coincide, they coincided.

Documented record — A documented event, compiled from cited sources after it happened. The dates are as good as the record, which for older events can mean the month rather than the day.

Event	Type	Period	Standing	Authority
Hurricane Katrina water and sanitation collapse	Flood	2005-08-29 – 2005-09-30	Documented record	Compiled record

Not shown on this chart

The 1976 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
The 2022 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Yorkshire drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cantareira water crisis, São Paulo — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cape Town Day Zero — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
European drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.

View the data behind this chart

Underlying data
Period	OBION RIVER AT HWY 51 NEAR OBION, TN (mm)
1930	450
1931	205
1932	618
1933	731
1934	334
1935	550
1936	164
1937	667
1938	353
1939	547
1940	269
1941	106
1942	314
1943	271
1944	346
1945	609
1946	437
1947	332
1948	508
1949	621
1950	903
1951	766
1952	457
1953	433
1954	241
1955	333
1956	413
1957	923
1967	465
1968	435
1969	430
1970	614
1971	467
1972	673
1973	842
1974	637
1975	831
1976	495
1977	367
1978	564
1979	864
1980	366
1981	381
1982	545
1983	716
1984	707
1985	427
1986	341
1987	361
1988	524
1989	765
1990	801
1991	513
1992	292
1993	396
1994	493
2002	653
2003	611
2004	492
2007	362
2008	578
2009	581
2010	430
2011	713
2012	250
2013	644
2014	552
2015	507
2016	485
2017	371
2018	702
2019	725
2020	660
2021	428
2022	513
2023	480
2024	429
2025	692

About this series

Source	United States Geological Survey — National Water Information System · US Government work — public domain
How the values came to exist	Derived Computed by Hydrionis
Period held	1930–2025
Completeness	81.3% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	3 separate periods inside 1930–2025 hold no value. The longest runs from 1958 to 1966 — 9 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1930 and is not continuous from it: 96 years separate the first value from the last, and 81% of the years between them are held. The span is not the record.
Inputs last read	2026-10-01 · when the records this was computed from were last read from their publishers
Calculation date	2026-08-24 · when the calculation method was last versioned, not a reading of any publisher
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

Every gauge Hydrionis holds within this area

Gauges within the Obion and what each holds
Gauge	Measures	Values	Record
OBION RIVER AT HWY 51 NEAR OBION, TN	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	186	1929–2026
OBION RIVER AT OBION, TN	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	158	1929–2026

How these gauges were attached to this water

Assigned by the publisher to a numbered basin Every gauge here is assigned to this drainage area by its own publisher, which issues the area an official code — 08010202. A drainage area is not a river: it contains the tributaries as well as the main channel, and a gauge in it may be on any of them.

What each gauge’s link to this water rests on
Gauge	Evidence	Established
OBION RIVER AT HWY 51 NEAR OBION, TN	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02
OBION RIVER AT OBION, TN	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02

What this record holds

Hydrionis decides which waters get a page, and which of those are offered to search, from what is actually held rather than from how the page reads. Five signals are counted; this record has 2 of them, which makes it a profile, not indexed.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	2	no
Years spanned	98	yes, 20 or more
Values held	344	no
Distinct measurements	4	yes, 2 or more
Publishers measuring it	1	no
Official identifiers	1	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/gauge-usgs-07026040.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

No bulk download is offered here, which is a licence position rather than a product one: at least one contributing publisher does not permit redistribution. The values can be read on the page, cited, and pointed to at source.

Attribution and citation

Suggested citation for Hydrionis

Hydrionis (2026), Obion gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-obion/

Cite Hydrionis where you rely on values Hydrionis computed, on the method that produced them, or on the compilation itself. The underlying measurements remain the publishers’ and their attribution requirements apply to you directly.

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: the Obion gauge records 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.

Where these figures come from

MeasuredHigh confidence2025-04-07

Source: USGS — National Water Information System, USGS site 07026040, annual peak streamflow. Licence: Open.

Method: The instantaneous maximum discharge of each water year as published by USGS, dated to the day it occurred. One value per October-to-September water year; where the publisher lists both a systematic and a historic peak for a year, the larger is the annual maximum. Values the publisher marks as maximum daily averages are not held here, because they are not instantaneous peaks. Values marked as bounded rather than measured are held as censored observations carrying the bound. Cubic feet per second are converted to cubic metres per second and the publisher unit is recorded alongside.

Rating curves are extrapolated at extreme discharges, so the largest values in a peak series carry the largest measurement uncertainty. Data from the U.S. Geological Survey National Water Information System, a work of the United States government and therefore in the public domain.

Retrieved 1 October 2026.