The monitoring network within this area

Hydrionis holds 543 values from 2 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

543

Values held

1912–2026

Record spans

Gauges within the Connoquenessing huc8 subbasin

2 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 Slippery Rock Creek at Wurtemburg, PA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1912–2022.

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	Slippery Rock Creek at Wurtemburg, PA (m³/s)
1912	306
1913	504
1914	177
1915	303
1916	200
1917	169
1918	286
1919	141
1920	311
1921	106
1923	214
1924	207
1925	194
1926	255
1927	227
1929	326
1930	188
1931	83.0
1932	138
1934	368
1935	162
1936	255
1937	538
1939	241
1940	239
1941	96.6
1942	220
1944	96.0
1945	254
1946	326
1947	98.0
1948	184
1950	211
1952	311
1953	127
1954	191
1956	340
1957	209
1958	186
1959	396
1960	241
1961	121
1962	141
1963	121
1964	345
1965	182
1966	195
1967	96.3
1968	215
1970	160
1971	177
1972	257
1973	150
1974	231
1975	199
1976	159
1977	189
1979	240
1980	168
1981	272
1982	217
1983	120
1984	195
1985	221
1986	187
1988	90.6
1989	211
1990	191
1992	101
1993	155
1994	228
1995	122
1996	252
1998	215
1999	157
2000	141
2001	88.6
2002	142
2003	191
2004	334
2005	207
2006	112
2007	162
2008	189
2009	143
2010	155
2011	221
2012	140
2013	118
2015	238
2016	135
2017	209
2018	192
2019	212
2020	186
2021	147
2022	235

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	1912–2022
Completeness	87.4% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	14 separate periods inside 1912–2022 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1912 and is not continuous from it: 111 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 Connoquenessing Creek near Zelienople, 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. 1920–2025.

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	Connoquenessing Creek near Zelienople, PA (mm)
1920	352
1921	517
1922	324
1923	432
1924	622
1925	342
1926	599
1927	811
1928	561
1929	576
1930	338
1931	281
1932	346
1933	386
1934	301
1935	481
1936	501
1937	674
1938	412
1939	372
1940	510
1941	326
1942	523
1943	455
1944	374
1945	672
1946	357
1947	434
1948	442
1949	330
1950	667
1951	529
1952	521
1953	318
1954	468
1955	357
1956	750
1957	423
1958	459
1959	485
1960	351
1961	369
1962	295
1963	279
1964	423
1965	383
1966	381
1967	386
1968	406
1969	286
1970	477
1971	356
1972	646
1973	537
1974	624
1975	554
1976	331
1977	429
1978	446
1979	458
1980	495
1981	408
1982	355
1983	462
1984	501
1985	555
1986	403
1987	413
1988	254
1989	474
1990	653
1991	256
1992	393
1993	435
1994	550
1995	338
1996	620
1997	459
1998	380
1999	306
2000	317
2001	311
2002	331
2003	594
2004	923
2005	471
2006	451
2007	542
2008	423
2009	368
2010	503
2011	706
2012	406
2013	482
2014	416
2015	545
2016	369
2017	553
2018	854
2019	732
2020	491
2022	495
2023	325
2024	520
2025	421

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	1920–2025
Completeness	99.1% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1920–2025 holds no value: 2021. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1920 and is not continuous from it: 106 years separate the first value from the last, and 99% 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 Connoquenessing and what each holds
Gauge	Measures	Values	Record
Connoquenessing Creek near Zelienople, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	321	1916–2026
Slippery Rock Creek at Wurtemburg, PA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	222	1912–2026

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 — 05030105. 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
Connoquenessing Creek near Zelienople, 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
Slippery Rock Creek at Wurtemburg, 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 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	115	yes, 20 or more
Values held	543	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-03106000.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), Connoquenessing gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-connoquenessing/

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 Connoquenessing 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 confidence2025-02-16

Source: USGS — National Water Information System, USGS site 03106000, 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.