The monitoring network within this area

Hydrionis holds 1,554 values from 6 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

1,554

Values held

1846–2026

Record spans

Gauges within the Lower Susquehanna-Swatara huc8 subbasin

6 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 Susquehanna River at Harrisburg, PA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1846–2024.

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	Susquehanna River at Harrisburg, PA (m³/s)
1846	13,649
1865	16,226
1868	11,808
1886	10,902
1889	18,519
1891	11,553
1892	7,646
1893	9,175
1894	17,358
1895	6,513
1896	7,504
1897	5,097
1898	8,920
1899	6,456
1900	6,739
1903	7,815
1905	8,665
1907	6,994
1908	8,410
1909	8,410
1910	9,401
1911	5,040
1912	7,051
1913	11,383
1914	10,137
1915	8,099
1916	10,732
1917	4,389
1918	8,155
1919	8,325
1920	11,978
1921	5,040
1923	7,391
1924	9,175
1925	10,732
1926	4,701
1928	7,136
1929	6,654
1930	5,012
1931	4,332
1932	6,938
1933	7,617
1934	3,993
1936	20,954
1937	6,541
1939	5,947
1940	11,836
1941	6,909
1942	8,212
1943	11,667
1944	6,003
1945	7,136
1946	13,989
1947	6,060
1948	8,722
1949	6,230
1950	8,495
1952	9,175
1953	6,116
1954	6,853
1955	5,012
1956	9,571
1957	7,079
1958	7,957
1959	6,513
1960	10,817
1961	11,100
1962	7,646
1963	7,051
1964	13,705
1965	3,851
1966	7,504
1967	5,154
1968	5,720
1970	9,713
1971	6,343
1972	28,883
1973	5,918
1975	14,980
1976	6,768
1978	7,136
1979	11,780
1980	5,805
1981	8,240
1982	5,578
1983	6,909
1984	12,063
1985	3,653
1986	10,109
1987	6,258
1988	5,352
1989	5,947
1990	3,710
1992	4,531
1993	11,610
1994	9,458
1995	4,955
1996	16,084
1998	8,948
1999	6,626
2000	6,060
2001	4,276
2002	5,493
2003	7,702
2004	15,772
2005	10,194
2006	10,845
2007	6,768
2008	9,061
2009	4,021
2010	8,580
2011	16,707
2013	5,663
2014	5,182
2015	4,984
2016	4,474
2017	5,097
2018	9,005
2020	6,739
2022	5,210
2023	4,616
2024	7,702

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	1846–2024
Completeness	68.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	21 separate periods inside 1846–2024 hold no value. The longest runs from 1847 to 1864 — 18 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1846 and is not continuous from it: 179 years separate the first value from the last, and 68% 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 Susquehanna River at Harrisburg, 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. 1891–2025.

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	Susquehanna River at Harrisburg, PA (mm)
1891	754
1892	559
1893	591
1894	595
1895	386
1896	500
1897	467
1898	596
1899	447
1900	415
1901	622
1902	632
1903	610
1904	496
1905	508
1906	448
1907	520
1908	514
1909	422
1910	398
1911	461
1912	532
1913	477
1914	468
1915	537
1916	607
1917	487
1918	515
1919	461
1920	508
1921	430
1922	411
1923	364
1924	537
1925	372
1926	485
1927	669
1928	526
1929	535
1930	317
1931	308
1932	427
1933	482
1934	370
1935	468
1936	537
1937	582
1938	401
1939	369
1940	507
1941	297
1942	511
1943	572
1944	387
1945	677
1946	497
1947	501
1948	505
1949	406
1950	655
1951	521
1952	587
1953	445
1954	394
1955	478
1956	595
1957	395
1958	526
1959	471
1960	507
1961	456
1962	404
1963	323
1964	406
1965	270
1966	354
1967	500
1968	417
1969	329
1970	539
1971	475
1972	854
1973	575
1974	515
1975	656
1976	566
1977	647
1978	562
1979	633
1980	350
1981	388
1982	427
1983	517
1984	599
1985	376
1986	507
1987	396
1988	331
1989	480
1990	593
1991	355
1992	435
1993	633
1994	652
1995	352
1996	802
1997	379
1998	540
1999	353
2000	465
2001	307
2002	448
2003	784
2004	750
2005	541
2006	594
2007	455
2008	531
2009	448
2010	472
2011	951
2012	403
2013	430
2014	453
2015	411
2016	353
2017	547
2018	939
2019	622
2020	449
2021	566
2022	476
2023	487
2024	560
2025	410

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	1891–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1891 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 Susquehanna-Swatara and what each holds
Gauge	Measures	Values	Record
Susquehanna River at Harrisburg, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	408	1846–2026
Swatara Creek at Harper Tavern, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	321	1889–2026
Sherman Creek at Shermans Dale, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	290	1927–2026
Conodoguinet Creek near Hogestown, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	275	1911–2026
Yellow Breeches Creek near Camp Hill, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	243	1910–2026
Lower Little Swatara Creek at Pine Grove, PA	catchment area, annual maximum river flow	17	1921–2026

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 — 02050305. 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
Susquehanna River at Harrisburg, 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
Swatara Creek at Harper Tavern, 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
Sherman Creek at Shermans Dale, 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
Conodoguinet Creek near Hogestown, 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
Yellow Breeches Creek near Camp Hill, 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
Lower Little Swatara Creek at Pine Grove, 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	5	yes, 3 or more
Years spanned	181	yes, 20 or more
Values held	1,554	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-01570500.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 Susquehanna-Swatara gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-lower-susquehanna-swatara/

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 Susquehanna-Swatara 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 confidence2024-04-05

Source: USGS — National Water Information System, USGS site 01570500, 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.