The monitoring network within this area

Hydrionis holds 656 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

656

Values held

1916–2026

Record spans

Gauges within the Oswegatchie 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 WEST BRANCH OSWEGATCHIE RIVER NEAR HARRISVILLE NY

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1917–2025.

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	WEST BRANCH OSWEGATCHIE RIVER NEAR HARRISVILLE NY (m³/s)
1917	138
1918	113
1919	95.1
1920	96.6
1921	130
1922	119
1923	106
1924	95.1
1926	163
1927	102
1928	135
1929	112
1930	196
1931	99.1
1932	105
1934	79.9
1935	117
1936	118
1937	119
1938	141
1939	74.2
1940	115
1942	76.5
1943	94.3
1944	92.9
1945	114
1946	104
1947	175
1948	168
1949	115
1950	101
1951	129
1952	73.1
1954	153
1955	126
1956	113
1957	72.5
1959	117
1960	160
1961	93.4
1962	100.0
1963	191
1964	90.9
1965	73.3
1966	67.7
1967	129
1968	74.5
1969	140
1970	77.6
1971	117
1972	128
1973	93.4
1974	151
1975	134
1976	122
1977	200
1978	114
1979	130
1981	113
1982	140
1983	66.3
1984	172
1986	106
1987	85.5
1988	111
1989	133
1990	150
1991	123
1992	126
1993	201
1994	170
1995	144
1996	176
1998	246
1999	153
2000	152
2001	153
2002	132
2003	111
2004	108
2005	128
2007	92.3
2008	88.6
2010	71.4
2012	60.6
2013	88.9
2014	176
2015	100
2016	87.8
2017	164
2019	88.6
2021	126
2022	119
2023	86.4
2025	138

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	1917–2025
Completeness	87.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	14 separate periods inside 1917–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1917 and is not continuous from it: 109 years separate the first value from the last, and 87% 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 WEST BRANCH OSWEGATCHIE RIVER NEAR HARRISVILLE 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. 1917–2025.

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	WEST BRANCH OSWEGATCHIE RIVER NEAR HARRISVILLE NY (mm)
1917	664
1918	843
1919	658
1920	674
1921	628
1922	652
1923	569
1924	783
1925	816
1926	804
1927	757
1928	831
1929	835
1930	734
1931	559
1932	843
1933	506
1934	489
1935	698
1936	694
1937	723
1938	722
1939	531
1940	566
1941	470
1942	604
1943	811
1944	508
1945	871
1946	677
1947	954
1948	664
1949	662
1950	631
1951	693
1952	576
1953	561
1954	910
1955	653
1956	612
1957	637
1958	618
1959	715
1960	641
1961	585
1962	639
1963	537
1964	521
1965	556
1966	511
1967	635
1968	556
1969	672
1970	629
1971	688
1972	818
1973	852
1974	759
1975	725
1976	1,054
1977	900
1978	662
1979	864
1980	661
1981	886
1982	778
1983	715
1984	735
1985	755
1986	933
1987	634
1988	617
1989	766
1990	892
1991	657
1992	810
1993	848
1994	710
1995	594
1996	1,044
1997	719
1998	776
1999	626
2000	878
2001	707
2002	764
2003	871
2004	706
2005	801
2006	884
2007	684
2008	980
2009	742
2010	720
2011	886
2012	560
2013	834
2014	879
2015	618
2016	659
2017	1,054
2018	825
2019	992
2020	531
2021	619
2022	745
2023	861
2024	766
2025	627

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	1917–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1917 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 Oswegatchie and what each holds
Gauge	Measures	Values	Record
WEST BRANCH OSWEGATCHIE RIVER NEAR HARRISVILLE NY	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	328	1916–2026
OSWEGATCHIE RIVER NEAR HEUVELTON NY	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	328	1916–2026

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 — 04290003. 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
WEST BRANCH OSWEGATCHIE RIVER NEAR HARRISVILLE 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
OSWEGATCHIE RIVER NEAR HEUVELTON 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	111	yes, 20 or more
Values held	656	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-04262500.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), Oswegatchie gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-oswegatchie/

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 Oswegatchie 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 confidence2025-03-17

Source: USGS — National Water Information System, USGS site 04262500, 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.