The monitoring network within this area

Hydrionis holds 577 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

577

Values held

1885–2026

Record spans

Gauges within the Thompson 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 Thompson River at Trenton, MO

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1909–2025.

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	Thompson River at Trenton, MO (m³/s)
1909	1,416
1922	453
1928	765
1930	169
1931	144
1933	382
1934	145
1935	680
1936	160
1937	394
1938	180
1939	643
1940	445
1941	915
1942	1,002
1943	759
1944	985
1945	801
1946	1,297
1947	2,690
1948	578
1949	544
1950	631
1951	589
1952	470
1953	470
1954	201
1955	272
1956	544
1957	450
1958	544
1959	1,339
1960	1,252
1961	1,042
1962	1,354
1963	1,056
1964	719
1965	1,138
1966	289
1967	1,555
1968	1,130
1969	1,198
1970	620
1971	496
1973	1,422
1974	354
1976	1,070
1977	283
1979	555
1980	479
1981	736
1982	1,042
1984	949
1985	345
1986	852
1987	793
1989	634
1990	646
1991	1,444
1992	1,999
1993	1,529
1994	229
1995	1,198
1996	951
1997	793
1998	1,184
2000	745
2001	793
2002	957
2003	117
2004	1,039
2005	292
2006	125
2007	1,699
2008	1,795
2009	1,869
2010	1,937
2011	668
2012	391
2013	1,623
2014	2,214
2015	960
2017	847
2018	521
2019	2,588
2020	869
2021	954
2023	1,303
2024	1,121
2025	643

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	1909–2025
Completeness	76.9% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	12 separate periods inside 1909–2025 hold no value. The longest runs from 1910 to 1921 — 12 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1909 and is not continuous from it: 117 years separate the first value from the last, and 77% 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 Thompson River at Trenton, MO, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1929–2025.

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	Thompson River at Trenton, MO (mm)
1929	272
1930	75.0
1931	214
1932	235
1933	58.0
1934	65.0
1935	281
1936	57.0
1937	139
1938	33.0
1939	112
1940	96.0
1941	196
1942	220
1943	167
1944	232
1945	312
1946	231
1947	434
1948	83.0
1949	138
1950	133
1951	318
1952	157
1953	106
1954	43.0
1955	68.0
1956	38.0
1957	54.0
1958	127
1959	398
1960	369
1961	427
1962	279
1963	125
1964	151
1965	253
1966	82.0
1967	196
1968	79.0
1969	231
1970	185
1971	120
1972	144
1973	564
1974	241
1975	157
1976	155
1977	149
1978	304
1979	194
1980	114
1981	137
1982	479
1983	236
1984	290
1985	140
1986	357
1987	300
1988	41.0
1989	45.0
1990	239
1991	257
1992	444
1993	641
1994	99.0
1995	320
1996	279
1997	211
1998	359
1999	179
2000	29.0
2001	281
2002	79.0
2003	33.0
2004	208
2005	102
2006	28.0
2007	269
2008	644
2009	409
2010	567
2011	236
2012	78.0
2013	198
2014	359
2015	404
2016	180
2017	133
2018	215
2019	496
2020	178
2021	220
2022	114
2023	92.0
2024	131
2025	119

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	1929–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1929 to 2025 is held.
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 Thompson and what each holds
Gauge	Measures	Values	Record
Thompson River at Trenton, MO	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	296	1909–2026
Thompson River at Davis City, IA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	281	1885–2026

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 — 10280102. 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
Thompson River at Trenton, MO	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
Thompson River at Davis City, IA	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	142	yes, 20 or more
Values held	577	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-06899500.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), Thompson gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-thompson/

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 Thompson 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 confidence2025-07-26

Source: USGS — National Water Information System, USGS site 06899500, 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.