The monitoring network within this area

Hydrionis holds 997 values from 4 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

997

Values held

1904–2026

Record spans

Gauges within the Ashuelot River-Connecticut River huc8 subbasin

4 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 ASHUELOT RIVER AT HINSDALE, NH

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1907–2025.

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	ASHUELOT RIVER AT HINSDALE, NH (m³/s)
1907	101
1909	221
1910	118
1911	101
1915	221
1916	180
1917	190
1918	160
1919	180
1920	270
1921	200
1922	180
1923	253
1924	210
1925	150
1926	150
1927	160
1929	155
1930	114
1931	160
1932	160
1933	232
1934	237
1935	171
1936	470
1937	206
1938	459
1939	165
1940	245
1941	46.2
1942	131
1943	78.7
1944	108
1945	129
1946	124
1947	92.0
1948	176
1949	83.8
1950	93.7
1952	123
1953	119
1954	98.3
1955	85.5
1956	167
1957	56.9
1958	92.6
1959	151
1960	249
1961	82.7
1962	144
1963	119
1964	87.2
1965	54.9
1966	83.8
1967	118
1968	131
1969	131
1970	138
1971	109
1972	149
1973	167
1975	122
1977	174
1978	111
1979	170
1980	116
1981	109
1982	145
1983	107
1984	286
1985	91.5
1986	163
1987	203
1989	114
1990	156
1992	110
1993	150
1994	128
1995	80.4
1996	157
1998	144
1999	173
2000	86.4
2001	138
2002	66.8
2003	126
2004	131
2005	149
2007	159
2008	135
2010	130
2011	143
2013	119
2014	111
2015	83.8
2016	153
2017	112
2018	138
2019	112
2021	247
2022	94.3
2023	179
2024	109
2025	147

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	1907–2025
Completeness	87.4% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	13 separate periods inside 1907–2025 hold no value. The longest runs from 1912 to 1914 — 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 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 ASHUELOT RIVER AT HINSDALE, NH, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1908–2025.

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	ASHUELOT RIVER AT HINSDALE, NH (mm)
1908	464
1909	405
1910	406
1911	415
1915	485
1916	701
1917	524
1918	463
1919	525
1920	795
1921	570
1922	608
1923	618
1924	486
1925	483
1926	467
1927	626
1928	640
1929	498
1930	301
1931	399
1932	439
1933	601
1934	543
1935	507
1936	638
1937	657
1938	770
1939	470
1940	557
1941	296
1942	458
1943	533
1944	490
1945	795
1946	460
1947	548
1948	563
1949	412
1950	543
1951	749
1952	567
1953	658
1954	628
1955	598
1956	555
1957	385
1958	521
1959	644
1960	740
1961	451
1962	497
1963	384
1964	370
1965	213
1966	364
1967	557
1968	566
1969	701
1970	575
1971	453
1972	802
1973	840
1974	609
1975	794
1976	653
1977	661
1978	469
1979	815
1980	357
1981	549
1982	676
1983	691
1984	771
1985	332
1986	745
1987	595
1988	495
1989	635
1990	771
1991	616
1992	416
1993	535
1994	575
1995	547
1996	886
1997	509
1998	583
1999	564
2000	653
2001	449
2002	420
2003	760
2004	608
2005	993
2006	837
2007	547
2008	888
2009	731
2010	621
2011	937
2012	474
2013	649
2014	820
2015	505
2016	425
2017	692
2018	906
2019	630
2020	544
2021	856
2022	571
2023	893
2024	582
2025	573

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	1908–2025
Completeness	97.5% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1908–2025 holds no value: 1912 to 1914, 3 years with no reading. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1908 and is not continuous from it: 118 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 Ashuelot River-Connecticut River and what each holds
Gauge	Measures	Values	Record
ASHUELOT RIVER AT HINSDALE, NH	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	347	1907–2026
CONNECTICUT RIVER AT MONTAGUE CITY, MA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	249	1904–2026
ASHUELOT RIVER NEAR GILSUM, NH	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	223	1922–2026
S BR ASHUELOT RIVER AT WEBB, NR MARLBOROUGH, NH	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	178	1920–2026

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 — 01080201. 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
ASHUELOT RIVER AT HINSDALE, NH	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
CONNECTICUT RIVER AT MONTAGUE CITY, MA	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
ASHUELOT RIVER NEAR GILSUM, NH	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 BR ASHUELOT RIVER AT WEBB, NR MARLBOROUGH, NH	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	4	yes, 3 or more
Years spanned	123	yes, 20 or more
Values held	997	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-01161000.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), Ashuelot River-Connecticut River gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-ashuelot-river-connecticut-river/

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 Ashuelot River-Connecticut River 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 confidence2025-05-10

Source: USGS — National Water Information System, USGS site 01161000, 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.