The monitoring network within this area

Hydrionis holds 583 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

583

Values held

1908–2026

Record spans

Gauges within the Lower Sangamon 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 SANGAMON RIVER AT RIVERTON, IL

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1908–2025.

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

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 (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	SANGAMON RIVER AT RIVERTON, IL (m³/s)
1908	541
1909	374
1910	199
1911	600
1912	447
1915	527
1916	674
1917	654
1918	283
1919	314
1920	447
1921	257
1922	643
1923	311
1924	269
1925	289
1926	932
1929	396
1930	278
1931	29.4
1933	530
1934	71.9
1935	360
1936	377
1937	391
1938	595
1939	733
1940	80.4
1941	121
1942	493
1943	1,945
1944	866
1945	498
1946	266
1947	456
1948	388
1949	354
1950	617
1951	821
1952	272
1953	156
1954	51.8
1955	128
1956	232
1957	640
1958	583
1959	575
1960	515
1961	566
1962	532
1963	257
1964	447
1965	402
1966	422
1968	657
1969	493
1970	663
1971	229
1972	515
1973	765
1975	425
1976	268
1977	821
1978	597
1979	1,252
1981	555
1982	813
1983	1,099
1984	388
1985	388
1986	172
1988	205
1989	171
1990	699
1992	396
1993	515
1994	1,311
1995	578
1996	903
1997	331
1998	538
1999	303
2000	129
2001	617
2002	1,467
2003	362
2004	311
2005	900
2006	311
2007	360
2008	946
2009	481
2011	580
2012	119
2013	844
2014	391
2015	479
2017	665
2018	274
2019	631
2020	623
2021	430
2022	351
2023	286
2024	274
2025	154

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	1908–2025
Completeness	89.8% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	10 separate periods inside 1908–2025 hold no value. The longest runs from 1913 to 1914 — 2 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1908 and is not continuous from it: 118 years separate the first value from the last, and 90% 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 SANGAMON RIVER NEAR OAKFORD, IL, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1910–2025.

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	SANGAMON RIVER NEAR OAKFORD, IL (mm)
1910	135
1915	209
1916	209
1917	163
1918	136
1929	368
1930	151
1931	55.0
1932	92.0
1933	256
1940	48.0
1941	158
1942	349
1943	344
1944	197
1945	236
1946	293
1947	271
1948	173
1949	215
1950	353
1951	318
1952	219
1953	91.0
1954	35.0
1955	79.0
1956	91.0
1957	290
1958	235
1959	186
1960	227
1961	218
1962	249
1963	81.0
1964	120
1965	193
1966	180
1967	270
1968	309
1969	315
1970	288
1971	155
1972	238
1973	453
1974	466
1975	295
1976	155
1977	229
1978	225
1979	322
1980	109
1981	352
1982	428
1983	305
1984	306
1985	352
1986	245
1987	123
1988	127
1989	99.0
1990	333
1991	311
1992	242
1993	654
1994	285
1995	308
1996	207
1997	154
1998	395
1999	245
2000	112
2001	247
2002	387
2003	159
2004	319
2005	237
2006	163
2007	208
2008	484
2009	568
2010	402
2011	309
2012	45.0
2013	276
2014	249
2015	357
2016	296
2017	217
2018	185
2019	477
2020	381
2021	317
2022	258
2023	176
2024	214
2025	122

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	1910–2025
Completeness	82.8% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	3 separate periods inside 1910–2025 hold no value. The longest runs from 1919 to 1928 — 10 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1910 and is not continuous from it: 116 years separate the first value from the last, and 83% 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 Lower Sangamon and what each holds
Gauge	Measures	Values	Record
SANGAMON RIVER NEAR OAKFORD, IL	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	302	1909–2026
SANGAMON RIVER AT RIVERTON, IL	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	281	1908–2026

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 — 07130008. 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
SANGAMON RIVER NEAR OAKFORD, IL	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
SANGAMON RIVER AT RIVERTON, IL	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	119	yes, 20 or more
Values held	583	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-05583000.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), Lower Sangamon gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-lower-sangamon/

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 Lower Sangamon 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 confidence2025-04-08

Source: USGS — National Water Information System, USGS site 05583000, 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.