The monitoring network within this area

Hydrionis holds 1,023 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

1,023

Values held

1889–2026

Record spans

Gauges within the Lower West Branch Susquehanna 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 WB Susquehanna River at Williamsport, PA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1889–2025.

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	WB Susquehanna River at Williamsport, PA (m³/s)
1889	7,136
1895	1,484
1896	2,059
1897	1,461
1898	3,993
1899	1,829
1900	2,112
1902	4,219
1903	3,002
1904	3,993
1905	3,511
1907	3,313
1908	2,917
1909	3,993
1910	2,888
1911	3,398
1912	3,200
1913	3,823
1914	3,370
1915	2,917
1916	3,993
1917	1,399
1918	4,106
1919	3,964
1920	3,823
1921	1,441
1923	4,163
1924	3,398
1925	3,540
1926	1,829
1927	3,313
1928	3,058
1929	2,676
1930	1,549
1931	1,659
1932	2,141
1933	2,033
1934	1,382
1935	1,526
1936	7,476
1937	2,690
1939	1,461
1940	4,134
1941	2,053
1942	3,115
1944	1,971
1945	2,747
1946	6,315
1947	1,405
1948	3,511
1950	2,860
1952	2,718
1953	2,356
1954	3,313
1955	1,659
1956	3,426
1957	2,008
1958	2,127
1959	4,248
1960	3,596
1961	3,851
1962	2,633
1963	2,832
1964	5,578
1965	1,951
1966	2,404
1967	1,906
1968	1,489
1970	2,588
1971	1,883
1972	7,900
1973	2,282
1974	1,917
1975	4,786
1976	2,333
1977	2,192
1978	2,056
1979	4,163
1981	2,973
1982	2,294
1983	1,291
1984	5,040
1985	1,430
1986	2,574
1988	2,047
1989	2,027
1990	1,348
1991	2,149
1992	1,059
1993	3,455
1994	3,200
1995	1,826
1996	5,409
1998	2,704
1999	2,039
2000	1,407
2001	937
2002	2,146
2003	2,217
2004	5,748
2005	2,532
2007	2,299
2008	2,296
2009	1,583
2010	3,341
2012	1,150
2013	2,090
2014	2,059
2015	1,625
2016	994
2017	1,691
2018	3,426
2019	1,951
2020	1,943
2022	2,362
2025	1,552

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	1889–2025
Completeness	84.7% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	16 separate periods inside 1889–2025 hold no value. The longest runs from 1890 to 1894 — 5 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1889 and is not continuous from it: 137 years separate the first value from the last, and 85% 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 WB Susquehanna River at Williamsport, PA, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1896–2025.

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	WB Susquehanna River at Williamsport, PA (mm)
1896	520
1897	502
1898	587
1899	480
1900	448
1901	624
1902	616
1903	677
1904	559
1905	585
1906	444
1907	540
1908	588
1909	488
1910	428
1911	745
1912	588
1913	586
1914	476
1915	542
1916	685
1917	535
1918	616
1919	601
1920	508
1921	552
1922	405
1923	457
1924	630
1925	382
1926	570
1927	783
1928	652
1929	621
1930	352
1931	362
1932	440
1933	533
1934	360
1935	485
1936	613
1937	663
1938	408
1939	358
1940	537
1941	321
1942	596
1943	583
1944	420
1945	766
1946	560
1947	503
1948	582
1949	442
1950	772
1951	583
1952	618
1953	507
1954	450
1955	494
1956	726
1957	444
1958	529
1959	542
1960	501
1961	485
1962	428
1963	369
1964	471
1965	359
1966	437
1967	601
1968	455
1969	368
1970	650
1971	482
1972	894
1973	669
1974	628
1975	754
1976	569
1977	692
1978	627
1979	749
1980	421
1981	550
1982	534
1983	544
1984	755
1985	492
1986	602
1987	456
1988	376
1989	534
1990	742
1991	399
1992	550
1993	738
1994	768
1995	407
1996	896
1997	481
1998	531
1999	404
2000	442
2001	352
2002	492
2003	843
2004	876
2005	529
2006	548
2007	439
2008	507
2009	448
2010	508
2011	867
2012	452
2013	463
2014	476
2015	522
2016	393
2017	585
2018	1,011
2019	683
2020	498
2021	560
2022	533
2023	435
2024	631
2025	440

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	1896–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1896 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 Lower West Branch Susquehanna and what each holds
Gauge	Measures	Values	Record
WB Susquehanna River at Williamsport, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	391	1889–2026
Lycoming Creek near Trout Run, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	335	1914–2026
Loyalsock Creek at Loyalsockville, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	297	1925–2026

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 — 02050206. 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
WB Susquehanna River at Williamsport, PA	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
Lycoming Creek near Trout Run, PA	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
Loyalsock Creek at Loyalsockville, PA	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	3	yes, 3 or more
Years spanned	138	yes, 20 or more
Values held	1,023	yes, 1000 or more
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-01551500.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), Lower West Branch Susquehanna gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-lower-west-branch-susquehanna/

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 Lower West Branch Susquehanna 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 01551500, 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.