The monitoring network within this area

Hydrionis holds 981 values from 3 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

981

Values held

1899–2026

Record spans

Gauges within the South Branch Potomac huc8 subbasin

3 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 SOUTH BRANCH POTOMAC RIVER NEAR SPRINGFIELD, WV

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1904–2025.

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	SOUTH BRANCH POTOMAC RIVER NEAR SPRINGFIELD, WV (m³/s)
1904	260
1905	331
1906	430
1929	1,031
1931	214
1932	1,203
1933	793
1934	283
1935	544
1936	4,049
1937	1,614
1939	1,351
1940	1,161
1941	300
1942	1,444
1944	343
1945	816
1946	311
1947	289
1948	833
1949	2,945
1950	535
1952	677
1953	382
1954	827
1955	2,078
1956	368
1957	456
1958	320
1959	377
1960	694
1961	583
1962	827
1963	1,470
1964	665
1965	419
1966	345
1967	1,288
1968	343
1969	224
1970	467
1971	470
1972	892
1973	1,169
1975	1,147
1976	1,651
1978	869
1979	968
1980	680
1981	218
1982	719
1983	733
1984	929
1985	691
1987	1,113
1988	623
1989	331
1990	303
1991	892
1992	510
1993	977
1994	1,090
1995	660
1996	4,163
1998	827
1999	259
2000	425
2001	306
2002	784
2003	1,911
2005	606
2006	343
2007	940
2008	745
2009	538
2010	926
2011	892
2013	733
2014	861
2015	371
2016	357
2017	320
2018	960
2020	447
2021	634
2022	614
2023	263
2024	521
2025	629

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	1904–2025
Completeness	73.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	12 separate periods inside 1904–2025 hold no value. The longest runs from 1907 to 1928 — 22 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1904 and is not continuous from it: 122 years separate the first value from the last, and 73% 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 SOUTH BRANCH POTOMAC RIVER NEAR SPRINGFIELD, WV, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1900–2024.

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	SOUTH BRANCH POTOMAC RIVER NEAR SPRINGFIELD, WV (mm)
1900	294
1901	425
1904	176
1905	273
1929	353
1930	109
1931	201
1932	321
1933	347
1934	176
1935	375
1936	491
1937	447
1938	200
1939	318
1940	314
1941	158
1942	344
1943	310
1944	294
1945	285
1946	230
1947	162
1948	376
1949	453
1950	361
1951	355
1952	333
1953	272
1954	258
1955	331
1956	271
1957	252
1958	285
1959	184
1960	303
1961	351
1962	320
1963	259
1964	269
1965	272
1966	242
1967	333
1968	235
1969	148
1970	294
1971	376
1972	583
1973	428
1974	322
1975	413
1976	308
1977	233
1978	371
1979	523
1980	341
1981	198
1982	342
1983	381
1984	434
1985	544
1986	261
1987	345
1988	204
1989	346
1990	253
1991	262
1992	240
1993	373
1994	481
1995	251
1996	801
1997	288
1998	486
1999	191
2000	209
2001	240
2002	291
2003	679
2004	413
2005	270
2006	262
2007	290
2008	334
2009	293
2010	284
2011	460
2012	214
2013	363
2014	300
2015	296
2016	280
2017	240
2018	683
2019	339
2020	335
2021	262
2022	257
2023	177
2024	278

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	1900–2024
Completeness	80.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1900–2024 hold no value. The longest runs from 1906 to 1928 — 23 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1900 and is not continuous from it: 125 years separate the first value from the last, and 80% 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 South Branch Potomac and what each holds
Gauge	Measures	Values	Record
SOUTH BRANCH POTOMAC RIVER NEAR SPRINGFIELD, WV	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	338	1899–2026
SOUTH BRANCH POTOMAC RIVER NEAR PETERSBURG, WV	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	326	1928–2026
S F SOUTH BRANCH POTOMAC RIVER NR MOOREFIELD, WV	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	317	1928–2026

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 — 02070001. 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
SOUTH BRANCH POTOMAC RIVER NEAR SPRINGFIELD, WV	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
SOUTH BRANCH POTOMAC RIVER NEAR PETERSBURG, WV	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
S F SOUTH BRANCH POTOMAC RIVER NR MOOREFIELD, WV	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 4 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	3	yes, 3 or more
Years spanned	128	yes, 20 or more
Values held	981	no
Distinct measurements	5	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-01608500.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), South Branch Potomac gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-south-branch-potomac/

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 South Branch Potomac 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 confidence2025-05-14

Source: USGS — National Water Information System, USGS site 01608500, 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.