The monitoring network within this area

Hydrionis holds 408 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.

2
Gauges
408
Values held
1910–2026
Record spans
Gauges within the Upper Cowlitz huc8 subbasin
2 monitoring points, positioned as the publisher records them.
Gauges within the Upper Cowlitz huc8 subbasinCOWLITZ RIVER AT PACKWOOD, WA, CISPUS RIVER NEAR RANDLE, WACOWLITZ RIVER AT PACKWOOD, WACISPUS RIVER NEAR RANDLE, WA

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.
Shading marks when something was recorded, not what caused the line.
Largest measured flow of each year at COWLITZ RIVER AT PACKWOOD, WALargest measured flow of each year at COWLITZ RIVER AT PACKWOOD, WA: COWLITZ RIVER AT PACKWOOD, WA in m³/s, from 1911 to 2025.Hurricane Katrina water and sanitation collapse05001,000m³/s19111934194619601977199120032017

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 recordA 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.

EventTypePeriodStandingAuthority
Hurricane Katrina water and sanitation collapseFlood2005-08-292005-09-30Documented record
Compiled record

Not shown on this chart

  • The 1976 droughtThis 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 droughtThis event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • Yorkshire droughtThis 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 PauloThis 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 ZeroThis event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • European droughtThis 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
PeriodCOWLITZ RIVER AT PACKWOOD, WA (m³/s)
1911396
1913185
1914371
1916368
1917266
1919456
1930144
1931211
1932456
19331,036
1934750
1936271
1937261
1938445
1939331
1940259
1941286
1942575
1943399
1945399
1946538
1947532
1949279
1951351
1952182
1953354
1955286
1956281
1958205
1959971
1960256
1962360
1964236
1966240
1967566
1968357
1970306
1972340
1974677
1975866
1977165
1979176
1980866
1982459
1984377
1985481
1986513
1987445
1988331
1990646
1991212
1993188
1994127
1995501
1996932
1997450
1998447
1999657
2001175
2002493
2003586
2005473
20061,192
2007430
2008748
2010260
2011728
2012345
2014493
2015878
2017345
2018227
2020396
2021510
2022510
2023544
2025253

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 existMeasured
Period held19112025
Completeness67.0% 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.
ContinuityThe 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 publisher2026-08-31
RedistributionPermitted by the upstream licences
Commercial reusePermitted by the upstream licences. No Hydrionis access tier can widen this.
MethodologyHow 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.
Shading marks when something was recorded, not what caused the line.
Water leaving the catchment above COWLITZ RIVER AT PACKWOOD, WA, as a depthWater leaving the catchment above COWLITZ RIVER AT PACKWOOD, WA, as a depth: COWLITZ RIVER AT PACKWOOD, WA in mm, from 1930 to 2024.Hurricane Katrina water and sanitation collapse1,0001,5002,0002,5003,000mm19301942195419661978199020022014

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 recordA 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.

EventTypePeriodStandingAuthority
Hurricane Katrina water and sanitation collapseFlood2005-08-292005-09-30Documented record
Compiled record

Not shown on this chart

  • The 1976 droughtThis 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 droughtThis event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • Yorkshire droughtThis 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 PauloThis 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 ZeroThis event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • European droughtThis 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
PeriodCOWLITZ RIVER AT PACKWOOD, WA (mm)
19301,420
19311,551
19322,329
19332,952
19342,320
19351,699
19361,853
19372,046
19381,707
19391,728
19401,444
19411,320
19421,484
19431,803
19441,184
19451,741
19462,415
19472,138
19481,926
19492,440
19502,906
19512,013
19521,478
19532,261
19542,263
19552,511
19562,535
19571,653
19582,232
19592,432
19601,974
19612,265
19622,022
19631,531
19642,170
19651,686
19661,605
19672,013
19682,000
19691,714
19701,657
19712,221
19722,807
19731,472
19742,681
19752,472
19761,841
19771,786
19781,397
19791,449
19801,868
19811,500
19822,016
19831,920
19841,696
19851,603
19861,568
19871,247
19881,702
19891,711
19902,108
19912,034
19921,288
19931,305
19941,657
19952,526
19962,096
19972,583
19981,605
19992,424
20001,532
20011,374
20021,755
20032,087
20042,138
20051,454
20062,345
20071,877
20082,082
20091,899
20101,935
20112,265
20122,506
20131,988
20142,570
20151,858
20162,026
20172,447
20181,824
20191,334
20202,100
20212,024
20221,809
20231,388
20241,573

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 existDerived Computed by Hydrionis
Period held19302024
Completeness100.0% of the periods in that span are held.
ContinuityContinuous: every year from 1930 to 2024 is held.
Last read from the publisher2026-08-24
RedistributionPermitted by the upstream licences
Commercial reusePermitted by the upstream licences. No Hydrionis access tier can widen this.
MethodologyHow this was produced

Every gauge Hydrionis holds within this area

Gauges within the Upper Cowlitz and what each holds
GaugeMeasuresValuesRecord
COWLITZ RIVER AT PACKWOOD, WAburned area within 50 km, catchment area, annual maximum river flow, mean river flow2371911–2026
CISPUS RIVER NEAR RANDLE, WAburned area within 50 km, catchment area, annual maximum river flow, mean river flow1711910–2026

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
GaugeEvidenceEstablished
COWLITZ RIVER AT PACKWOOD, WAStated 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/42026-08-26
CISPUS RIVER NEAR RANDLE, WAStated 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/42026-08-26

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 3 of them, which makes it a full profile.

Information-gain signals held for this water body
SignalHeldCounts
Gauges holding a real record2no
Years spanned117yes, 20 or more
Values held408no
Distinct measurements4yes, 2 or more
Publishers measuring it2yes, 2 or more
Official identifiers1recorded, not counted

Use this data

Use this data

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 2026-09-02, 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: USGSNational 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 31 August 2026.