The monitoring network within this area

Hydrionis holds 674 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

674

Values held

1904–2026

Record spans

Gauges within the Chemung 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 CHEMUNG RIVER AT CHEMUNG NY

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	CHEMUNG RIVER AT CHEMUNG NY (m³/s)
1904	1,790
1905	1,263
1906	926
1907	643
1908	1,271
1909	1,436
1910	1,614
1911	510
1912	1,461
1913	1,487
1914	1,696
1915	1,577
1916	1,951
1917	782
1918	1,897
1919	1,651
1920	1,733
1921	821
1922	872
1923	1,073
1924	1,407
1925	1,342
1926	835
1927	1,356
1929	1,625
1930	745
1931	612
1932	1,116
1933	946
1934	915
1935	2,435
1936	2,472
1937	1,246
1939	1,926
1940	2,486
1941	1,566
1942	1,719
1944	1,045
1945	1,532
1946	3,738
1947	1,883
1948	1,962
1949	580
1950	2,274
1951	2,302
1952	1,538
1953	1,303
1954	1,056
1955	960
1957	1,124
1958	1,484
1959	1,727
1960	2,081
1961	1,824
1962	833
1963	1,093
1964	2,656
1965	394
1966	923
1967	810
1968	850
1969	736
1970	980
1971	1,269
1972	5,352
1974	833
1975	3,540
1976	1,487
1977	957
1978	1,337
1979	1,741
1981	790
1982	1,019
1983	665
1984	1,733
1985	578
1986	1,167
1987	753
1988	759
1989	1,073
1990	722
1992	940
1993	1,232
1994	1,376
1995	949
1996	2,203
1998	1,246
1999	827
2000	864
2001	951
2002	668
2003	1,051
2004	1,894
2005	1,659
2007	1,509
2008	1,291
2009	787
2010	1,223
2011	1,356
2013	886
2014	1,152
2015	640
2016	866
2017	841
2018	971
2020	1,002
2021	1,402
2023	419
2024	866
2025	759

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	90.2% 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. 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 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 CHEMUNG RIVER AT CHEMUNG NY, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1907–2025.

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	CHEMUNG RIVER AT CHEMUNG NY (mm)
1907	307
1908	333
1909	292
1911	226
1912	364
1916	497
1917	415
1918	375
1919	345
1920	282
1921	253
1922	310
1923	218
1924	339
1925	284
1926	318
1927	555
1928	354
1929	439
1930	274
1931	240
1932	324
1933	285
1934	199
1935	374
1936	417
1937	448
1938	275
1939	267
1940	430
1941	191
1942	401
1943	416
1944	254
1945	531
1946	386
1947	432
1948	374
1949	212
1950	495
1951	396
1952	415
1953	280
1954	246
1955	367
1956	462
1957	310
1958	395
1959	406
1960	404
1961	360
1962	251
1963	226
1964	294
1965	167
1966	261
1967	360
1968	315
1969	267
1970	359
1971	335
1972	680
1973	379
1974	341
1975	488
1976	439
1977	496
1978	418
1979	436
1980	250
1981	312
1982	328
1983	340
1984	545
1985	237
1986	368
1987	278
1988	208
1989	337
1990	459
1991	261
1992	447
1993	498
1994	506
1995	248
1996	640
1997	285
1998	445
1999	240
2000	342
2001	232
2002	315
2003	587
2004	606
2005	464
2006	513
2007	350
2008	374
2009	264
2010	349
2011	708
2012	259
2013	300
2014	324
2015	294
2016	274
2017	411
2018	638
2019	417
2020	331
2021	512
2022	304
2023	325
2024	359
2025	272

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	1907–2025
Completeness	96.6% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1907–2025 hold no value. The longest runs from 1913 to 1915 — 3 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1907 and is not continuous from it: 119 years separate the first value from the last, and 97% 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 Chemung and what each holds
Gauge	Measures	Values	Record
CHEMUNG RIVER AT CHEMUNG NY	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	352	1904–2026
COHOCTON RIVER NEAR CAMPBELL NY	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	322	1918–2026

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 — 02050105. 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
CHEMUNG RIVER AT CHEMUNG NY	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
COHOCTON RIVER NEAR CAMPBELL NY	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	123	yes, 20 or more
Values held	674	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-01531000.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), Chemung gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-chemung/

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 Chemung 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 confidence2025-05-07

Source: USGS — National Water Information System, USGS site 01531000, 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.