The monitoring network within this area

Hydrionis holds 812 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

812

Values held

1904–2026

Record spans

Gauges within the Winnipesaukee River 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 MERRIMACK RIVER AT FRANKLIN JUNCTION, NH

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	MERRIMACK RIVER AT FRANKLIN JUNCTION, NH (m³/s)
1904	600
1905	564
1906	767
1907	496
1909	850
1911	402
1912	558
1913	838
1914	915
1915	869
1916	643
1917	694
1919	745
1920	787
1922	881
1923	1,237
1924	547
1925	1,059
1926	583
1927	1,784
1929	773
1930	660
1931	535
1932	773
1933	869
1934	833
1935	680
1936	2,350
1937	637
1938	1,676
1940	889
1942	510
1943	453
1945	493
1947	476
1948	498
1949	496
1950	572
1951	634
1952	603
1953	626
1954	566
1955	425
1956	464
1957	230
1958	549
1959	439
1960	617
1961	371
1962	521
1964	558
1965	255
1966	314
1967	496
1968	442
1969	629
1971	490
1972	487
1973	541
1975	391
1976	626
1977	501
1978	445
1983	450
1985	276
1986	580
1987	501
1988	377
1989	459
1990	518
1992	382
1993	515
1994	496
1995	320
1996	544
1997	524
1998	527
1999	538
2000	490
2001	498
2002	479
2003	419
2005	530
2006	589
2007	490
2008	462
2010	456
2011	518
2012	419
2014	507
2016	462
2017	450
2019	496
2020	439
2021	343
2023	467
2025	453

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	79.5% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	22 separate periods inside 1904–2025 hold no value. The longest runs from 1979 to 1982 — 4 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 80% 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 MERRIMACK RIVER AT FRANKLIN JUNCTION, 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. 1906–2025.

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	MERRIMACK RIVER AT FRANKLIN JUNCTION, NH (mm)
1906	628
1907	703
1908	584
1909	588
1910	552
1911	538
1912	700
1913	614
1914	582
1915	584
1916	762
1917	681
1918	564
1920	816
1921	609
1922	794
1923	576
1924	625
1925	701
1926	578
1927	666
1928	652
1929	605
1930	496
1931	451
1932	630
1933	588
1934	585
1935	610
1936	883
1937	826
1938	777
1939	591
1940	633
1941	394
1942	499
1943	688
1944	521
1945	822
1946	674
1947	642
1948	509
1949	491
1950	581
1951	810
1952	764
1953	767
1954	889
1955	594
1956	651
1957	459
1958	610
1959	637
1960	745
1961	468
1962	567
1963	506
1964	469
1965	347
1966	481
1967	539
1968	568
1969	818
1970	626
1971	531
1972	698
1973	1,017
1974	703
1975	699
1976	769
1977	686
2002	431
2003	761
2004	560
2005	998
2006	985
2007	634
2008	1,036
2009	848
2010	693
2011	946
2012	596
2013	623
2014	707
2015	541
2016	507
2017	788
2018	764
2019	826
2020	597
2021	563
2022	586
2023	946
2024	666
2025	537

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	1906–2025
Completeness	79.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1906–2025 hold no value. The longest runs from 1978 to 2001 — 24 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1906 and is not continuous from it: 120 years separate the first value from the last, and 79% 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 Winnipesaukee River and what each holds
Gauge	Measures	Values	Record
MERRIMACK RIVER AT FRANKLIN JUNCTION, NH	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	309	1904–2026
SOUHEGAN RIVER AT MERRIMACK, NH	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	294	1909–2026
SUNCOOK RIVER AT NORTH CHICHESTER, NH	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	209	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 — 01070002. 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
MERRIMACK RIVER AT FRANKLIN JUNCTION, 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
SOUHEGAN RIVER AT MERRIMACK, 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
SUNCOOK RIVER AT NORTH CHICHESTER, 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 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	3	yes, 3 or more
Years spanned	123	yes, 20 or more
Values held	812	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-01081500.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), Winnipesaukee River gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-winnipesaukee-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 Winnipesaukee 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 confidence2025-03-19

Source: USGS — National Water Information System, USGS site 01081500, 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.