The monitoring network within this area

Hydrionis holds 1,480 values from 5 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.

5

Gauges

1,480

Values held

1908–2026

Record spans

Gauges within the Upper Cowlitz huc8 subbasin

5 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 COWLITZ RIVER AT PACKWOOD, WA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1911–2025.

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	COWLITZ RIVER AT PACKWOOD, WA (m³/s)
1911	396
1913	185
1914	371
1916	368
1917	266
1919	456
1930	144
1931	211
1932	456
1933	1,036
1934	750
1936	271
1937	261
1938	445
1939	331
1940	259
1941	286
1942	575
1943	399
1945	399
1946	538
1947	532
1949	279
1951	351
1952	182
1953	354
1955	286
1956	281
1958	205
1959	971
1960	256
1962	360
1964	236
1966	240
1967	566
1968	357
1970	306
1972	340
1974	677
1975	866
1977	165
1979	176
1980	866
1982	459
1984	377
1985	481
1986	513
1987	445
1988	331
1990	646
1991	212
1993	188
1994	127
1995	501
1996	932
1997	450
1998	447
1999	657
2001	175
2002	493
2003	586
2005	473
2006	1,192
2007	430
2008	748
2010	260
2011	728
2012	345
2014	493
2015	878
2017	345
2018	227
2020	396
2021	510
2022	510
2023	544
2025	253

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	1911–2025
Completeness	67.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	29 separate periods inside 1911–2025 hold no value. The longest runs from 1920 to 1929 — 10 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1911 and is not continuous from it: 115 years separate the first value from the last, and 67% 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 COWLITZ RIVER AT PACKWOOD, WA, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1930–2024.

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	COWLITZ RIVER AT PACKWOOD, WA (mm)
1930	1,420
1931	1,551
1932	2,329
1933	2,952
1934	2,320
1935	1,699
1936	1,853
1937	2,046
1938	1,707
1939	1,728
1940	1,444
1941	1,320
1942	1,484
1943	1,803
1944	1,184
1945	1,741
1946	2,415
1947	2,138
1948	1,926
1949	2,440
1950	2,906
1951	2,013
1952	1,478
1953	2,261
1954	2,263
1955	2,511
1956	2,535
1957	1,653
1958	2,232
1959	2,432
1960	1,974
1961	2,265
1962	2,022
1963	1,531
1964	2,170
1965	1,686
1966	1,605
1967	2,013
1968	2,000
1969	1,714
1970	1,657
1971	2,221
1972	2,807
1973	1,472
1974	2,681
1975	2,472
1976	1,841
1977	1,786
1978	1,397
1979	1,449
1980	1,868
1981	1,500
1982	2,016
1983	1,920
1984	1,696
1985	1,603
1986	1,568
1987	1,247
1988	1,702
1989	1,711
1990	2,108
1991	2,034
1992	1,288
1993	1,305
1994	1,657
1995	2,526
1996	2,096
1997	2,583
1998	1,605
1999	2,424
2000	1,532
2001	1,374
2002	1,755
2003	2,087
2004	2,138
2005	1,454
2006	2,345
2007	1,877
2008	2,082
2009	1,899
2010	1,935
2011	2,265
2012	2,506
2013	1,988
2014	2,570
2015	1,858
2016	2,026
2017	2,447
2018	1,824
2019	1,334
2020	2,100
2021	2,024
2022	1,809
2023	1,388
2024	1,573

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	Derived Computed by Hydrionis
Period held	1930–2024
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1930 to 2024 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

The snow standing above this water

3 automated snow stations sit inside this drainage area, weighing the snowpack rather than measuring how deep it is.

1,252

Fullest snowpack recorded at Potato Hill, in 1999 (mm of water)

129

Thinnest, in 2005 (mm of water)

March

Month the pack is usually at its fullest

June

Month the pack has gone by, in half of years

Peak snowpack at Potato Hill

Water years 1984–2026. Each point is the fullest month of that snow season.

A water year runs October to September and is named for the year it ends, so the snow of one winter stays in one point. The value is the fullest month, not the fullest day: a pack that peaked sharply mid-month reads lower here than a single measurement taken at the right moment would.

View the data behind this chart

Underlying data
Period	Potato Hill (mm)
1984	537
1985	805
1986	542
1987	495
1988	583
1989	618
1990	674
1991	530
1992	396
1993	527
1994	536
1995	585
1996	451
1997	966
1998	675
1999	1,252
2000	855
2001	410
2002	878
2003	596
2004	616
2005	129
2006	864
2007	760
2008	1,153
2009	780
2010	760
2011	1,066
2012	1,067
2013	739
2014	742
2015	236
2016	767
2017	836
2018	856
2019	839
2020	815
2021	965
2022	830
2023	948
2024	821
2025	859
2026	425

Read against the river

Potato Hill and COWLITZ RIVER AT PACKWOOD, WA both sit in this drainage area, and their records overlap by 41 years. That is the span the two have in common, not a count of years both actually hold — either record may have gaps inside it. The two are shown separately rather than on one axis: millimetres of stored water and cubic metres per second are not commensurable, and a difference between them would mean nothing.

Being in the same drainage area does not put the snowpack upstream of the gauge. A subbasin is an area, and snow on one tributary can join the river below a gauge on another — so a weak relationship here may say more about which tributary was measured than about the snow.

Every gauge Hydrionis holds within this area

Gauges within the Upper Cowlitz and what each holds
Gauge	Measures	Values	Record
COWLITZ RIVER AT PACKWOOD, WA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	333	1911–2026
CISPUS RIVER NEAR RANDLE, WA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	237	1910–2026
LAKE CREEK NEAR PACKWOOD, WA	catchment area, annual maximum river flow	51	1912–2026
COWLITZ RIVER AT RANDLE, WA	catchment area, annual maximum river flow	33	1994–2026
LAKE CREEK AT MOUTH NEAR PACKWOOD, WA	catchment area, annual maximum river flow	24	1908–2026

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 — 17080004. 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
COWLITZ RIVER AT PACKWOOD, WA	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
CISPUS RIVER NEAR RANDLE, WA	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
LAKE CREEK NEAR PACKWOOD, WA	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
COWLITZ RIVER AT RANDLE, WA	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
LAKE CREEK AT MOUTH NEAR PACKWOOD, WA	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 5 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	119	yes, 20 or more
Values held	1,480	yes, 1000 or more
Distinct measurements	6	yes, 2 or more
Publishers measuring it	2	yes, 2 or more
Official identifiers	1	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/gauge-usgs-14226500.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), Upper Cowlitz gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-upper-cowlitz/

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 Upper Cowlitz 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 confidence2025-02-23

Source: USGS — National Water Information System, USGS site 14226500, 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.