The monitoring network within this area

Hydrionis holds 474 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

474

Values held

1901–2026

Record spans

Gauges within the Appomattox 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 APPOMATTOX RIVER AT MATTOAX, VA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1901–2025.

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	APPOMATTOX RIVER AT MATTOAX, VA (m³/s)
1901	379
1902	340
1903	300
1904	173
1905	142
1926	54.9
1928	317
1929	135
1931	97.7
1932	190
1933	144
1934	221
1936	292
1937	569
1938	250
1939	111
1940	991
1941	87.2
1942	103
1943	161
1944	292
1945	292
1947	122
1948	210
1949	176
1951	73.3
1952	164
1954	119
1955	343
1957	90.3
1958	135
1959	183
1960	180
1961	128
1962	200
1963	129
1964	99.1
1965	96.8
1966	110
1967	77.6
1968	103
1969	123
1970	75.3
1971	254
1972	881
1974	236
1975	309
1976	182
1978	396
1979	612
1981	65.1
1982	134
1983	236
1984	273
1985	119
1987	320
1989	146
1990	125
1991	142
1992	85.2
1993	337
1995	152
1996	391
1998	309
1999	134
2000	126
2001	138
2002	70.2
2003	382
2005	115
2006	124
2007	225
2008	109
2009	247
2011	99.4
2012	75.9
2015	70.8
2017	107
2018	185
2020	174
2022	89.5
2023	94.0
2024	208
2025	205

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	1901–2025
Completeness	67.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	21 separate periods inside 1901–2025 hold no value. The longest runs from 1906 to 1925 — 20 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1901 and is not continuous from it: 125 years separate the first value from the last, and 67% of the years between them are held. The span is not the record.
Last read from the publisher	2026-08-31
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 APPOMATTOX RIVER AT FARMVILLE, VA, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1927–2025.

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	APPOMATTOX RIVER AT FARMVILLE, VA (mm)
1927	254
1928	376
1929	309
1930	151
1931	178
1932	333
1933	264
1934	314
1935	478
1936	430
1937	556
1938	363
1939	344
1940	480
1941	196
1942	292
1943	270
1944	415
1945	418
1946	365
1947	314
1948	484
1949	359
1950	331
1951	309
1952	375
1953	257
1954	237
1955	286
1956	191
1957	258
1958	353
1959	191
1960	302
1961	418
1962	370
1963	208
1964	186
1965	175
1966	175
1967	198
1968	158
1969	151
1970	140
1971	444
1972	713
1973	500
1974	384
1975	519
1976	361
1977	211
1978	525
1979	617
1980	323
1981	166
1982	325
1983	419
1984	412
1985	368
1986	188
1987	339
1988	196
1989	406
1990	383
1991	301
1992	271
1993	538
1994	472
1995	329
1996	554
1997	307
1998	517
1999	221
2000	201
2001	165
2002	165
2003	656
2004	318
2005	260
2006	264
2007	251
2008	218
2009	362
2010	298
2011	207
2012	139
2013	334
2014	340
2015	266
2016	306
2017	172
2018	510
2019	364
2020	558
2021	344
2022	227
2023	265
2024	456
2025	318

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	1927–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1927 to 2025 is held.
Last read from the publisher	2026-08-24
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 Appomattox and what each holds
Gauge	Measures	Values	Record
APPOMATTOX RIVER AT MATTOAX, VA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	238	1901–2026
APPOMATTOX RIVER AT FARMVILLE, VA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	236	1926–2026

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 — 02080207. 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
APPOMATTOX RIVER AT MATTOAX, VA	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	2026-08-26
APPOMATTOX RIVER AT FARMVILLE, VA	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	2026-08-26

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 3 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	2	no
Years spanned	126	yes, 20 or more
Values held	474	no
Distinct measurements	4	yes, 2 or more
Publishers measuring it	2	yes, 2 or more
Official identifiers	1	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/gauge-usgs-02040000.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), Appomattox gauge records, accessed 2026-09-02, hydrionis.com/waters/united-states-appomattox/

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 Appomattox 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 confidence2025-02-19

Source: USGS — National Water Information System, USGS site 02040000, 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 31 August 2026.