The monitoring network within this area

Hydrionis holds 590 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

590

Values held

1902–2026

Record spans

Gauges within the Penobscot 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 Penobscot River at West Enfield, Maine

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1902–2025.

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	Penobscot River at West Enfield, Maine (m³/s)
1902	2,149
1903	1,835
1904	1,543
1905	1,002
1906	1,756
1907	2,622
1908	2,008
1909	2,432
1910	1,121
1911	1,127
1912	1,781
1914	1,906
1915	1,523
1916	1,039
1917	2,489
1918	1,152
1919	1,274
1920	2,047
1921	1,455
1922	1,710
1923	4,332
1924	1,523
1925	957
1926	1,911
1927	1,722
1929	1,945
1930	1,424
1931	1,254
1932	1,968
1933	1,603
1934	2,376
1935	1,722
1936	3,540
1937	1,365
1938	1,186
1939	1,444
1940	3,200
1941	1,220
1942	1,603
1943	1,305
1945	1,761
1946	1,385
1947	2,240
1948	1,801
1949	903
1950	2,296
1952	1,436
1953	2,594
1954	2,350
1955	1,982
1956	1,331
1957	821
1958	2,945
1959	1,424
1961	2,325
1962	1,175
1963	1,923
1965	923
1966	960
1968	1,283
1969	1,767
1970	1,960
1971	2,413
1972	1,838
1973	3,625
1975	1,345
1976	3,115
1977	1,518
1978	1,515
1979	2,945
1980	1,155
1981	2,707
1982	1,903
1983	3,341
1984	3,171
1985	637
1986	1,405
1987	4,163
1988	1,036
1989	2,237
1990	1,113
1991	2,005
1992	1,277
1993	2,860
1994	2,775
1995	784
1996	2,027
1998	2,132
1999	1,339
2000	2,254
2001	1,688
2002	1,303
2003	1,356
2005	3,030
2007	2,033
2008	3,568
2009	2,421
2010	1,926
2012	1,724
2013	1,526
2014	2,792
2015	1,747
2017	2,220
2018	2,325
2019	2,424
2020	2,263
2022	1,147
2023	2,806
2025	1,356

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	1902–2025
Completeness	87.9% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	15 separate periods inside 1902–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1902 and is not continuous from it: 124 years separate the first value from the last, and 88% 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 Penobscot River at West Enfield, Maine, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1903–2025.

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	Penobscot River at West Enfield, Maine (mm)
1903	517
1904	554
1905	373
1906	605
1907	790
1908	586
1909	734
1910	541
1911	379
1912	761
1913	670
1914	559
1915	502
1916	531
1917	821
1918	673
1919	683
1920	743
1921	547
1922	553
1923	532
1924	447
1925	582
1926	588
1927	638
1928	692
1929	552
1930	525
1931	521
1932	629
1933	534
1934	608
1935	525
1936	784
1937	597
1938	642
1939	545
1940	612
1941	408
1942	534
1943	601
1944	466
1945	698
1946	560
1947	660
1948	498
1949	471
1950	661
1951	708
1952	573
1953	662
1954	956
1955	634
1956	487
1957	458
1958	702
1959	708
1960	637
1961	700
1962	570
1963	745
1964	452
1965	436
1966	544
1967	579
1968	512
1969	756
1970	690
1971	565
1972	717
1973	989
1974	715
1975	556
1976	901
1977	760
1978	576
1979	850
1980	510
1981	779
1982	622
1983	852
1984	758
1985	406
1986	604
1987	546
1988	467
1989	586
1990	799
1991	670
1992	527
1993	613
1994	589
1995	514
1996	911
1997	578
1998	699
1999	664
2000	674
2001	366
2002	451
2003	661
2004	492
2005	1,019
2006	846
2007	671
2008	861
2009	787
2010	756
2011	834
2012	661
2013	720
2014	801
2015	662
2016	576
2017	704
2018	684
2019	819
2020	634
2021	487
2022	702
2023	873
2024	593
2025	509

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	1903–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1903 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 Penobscot River and what each holds
Gauge	Measures	Values	Record
Penobscot River at West Enfield, Maine	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	371	1902–2026
PASSADUMKEAG RIVER AT LOWELL, ME	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	192	1915–2026
Kenduskeag Stream near Bangor, Maine	catchment area, annual maximum river flow	27	1909–2026

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 — 01020005. 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
Penobscot River at West Enfield, Maine	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
PASSADUMKEAG RIVER AT LOWELL, ME	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
Kenduskeag Stream near Bangor, Maine	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	125	yes, 20 or more
Values held	590	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-01034500.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), Penobscot River gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-penobscot-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 Penobscot 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 01034500, 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.