The monitoring network within this area

Hydrionis holds 1,487 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.

3

Gauges

1,487

Values held

1906–2026

Record spans

Gauges within the South Umpqua 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 COW CREEK NEAR AZALEA, OR

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1928–2025.

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	COW CREEK NEAR AZALEA, OR (m³/s)
1928	21.6
1929	16.0
1931	11.2
1933	75.9
1934	18.1
1935	18.1
1936	69.1
1937	62.3
1938	109
1939	52.1
1940	81.6
1941	53.5
1943	109
1945	45.0
1947	35.7
1948	129
1949	77.0
1950	41.6
1952	81.0
1953	121
1954	108
1955	147
1957	98.0
1958	116
1959	87.8
1960	58.9
1961	86.9
1962	81.3
1964	109
1966	94.0
1967	57.8
1968	56.6
1969	96.3
1970	153
1971	142
1972	69.7
1974	300
1975	76.7
1977	4.30
1978	54.9
1979	46.2
1980	85.8
1981	237
1983	225
1984	103
1986	21.4
1987	16.5
1988	6.88
1989	6.77
1990	2.61
1991	4.33
1993	13.1
1995	30.0
1996	24.2
1997	70.5
1998	25.5
1999	26.6
2000	29.4
2002	12.0
2003	27.7
2004	6.12
2006	38.2
2008	22.0
2009	5.41
2011	26.8
2012	36.2
2013	4.56
2015	9.57
2016	30.6
2017	29.7
2018	3.94
2019	17.0
2020	3.74
2021	3.11
2022	3.11
2023	3.54
2024	10.3
2025	37.9

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	1928–2025
Completeness	79.6% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	20 separate periods inside 1928–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1928 and is not continuous from it: 98 years separate the first value from the last, and 80% 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 COW CREEK NEAR AZALEA, OR, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1930–2025.

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	COW CREEK NEAR AZALEA, OR (mm)
1930	221
1931	201
1933	446
1934	238
1935	330
1936	368
1937	492
1938	712
1939	282
1940	556
1941	393
1942	576
1943	464
1944	208
1945	507
1946	452
1947	351
1948	596
1949	297
1950	706
1951	655
1952	591
1953	717
1954	580
1955	541
1956	797
1957	511
1958	612
1959	380
1960	418
1961	503
1962	389
1963	465
1964	661
1965	462
1966	616
1967	393
1968	381
1969	494
1970	591
1971	741
1972	528
1973	584
1974	873
1975	695
1976	304
1977	199
1978	345
1979	439
1980	484
1981	518
1982	625
1983	900
1984	661
1985	271
1986	275
1987	301
1988	264
1989	351
1990	236
1991	254
1992	227
1993	400
1994	214
1995	603
1996	817
1997	556
1998	700
1999	588
2000	390
2001	165
2002	298
2003	446
2004	306
2005	295
2006	696
2007	345
2008	398
2009	246
2010	360
2011	510
2012	563
2013	368
2014	220
2015	334
2016	629
2017	670
2018	219
2019	333
2020	230
2021	249
2022	191
2023	243
2024	442
2025	529

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	1930–2025
Completeness	99.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1930–2025 holds no value: 1932. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1930 and is not continuous from it: 96 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

The snow standing above this water

1 automated snow station sits inside this drainage area, weighing the snowpack rather than measuring how deep it is.

503

Fullest snowpack recorded at King Mountain, in 2008 (mm of water)

6

Thinnest, in 1992 (mm of water)

February

Month the pack is usually at its fullest

April

Month the pack has gone by, in half of years

Peak snowpack at King Mountain

Water years 1982–2026. 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	King Mountain (mm)
1982	119
1983	140
1984	21.0
1985	223
1986	50.0
1987	44.0
1988	102
1989	241
1990	163
1991	84.0
1992	6.00
1993	399
1994	42.0
1995	202
1996	67.0
1997	71.0
1998	125
1999	422
2000	99.0
2001	55.0
2002	235
2003	89.0
2004	130
2005	100
2006	152
2007	50.0
2008	503
2009	93.0
2010	28.0
2011	270
2012	138
2013	383
2014	10.0
2015	8.00
2016	246
2017	327
2018	142
2019	357
2020	89.0
2021	226
2022	181
2023	385
2024	124
2025	98.0
2026	11.0

Read against the river

King Mountain and SOUTH UMPQUA RIVER AT TILLER, OR both sit in this drainage area, and their records overlap by 43 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 South Umpqua and what each holds
Gauge	Measures	Values	Record
COW CREEK NEAR AZALEA, OR	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	324	1928–2026
SOUTH UMPQUA RIVER NEAR BROCKWAY, OR	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	313	1906–2026
SOUTH UMPQUA RIVER AT TILLER, OR	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	298	1910–2026

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 — 17100302. 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
COW CREEK NEAR AZALEA, OR	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
SOUTH UMPQUA RIVER NEAR BROCKWAY, OR	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
SOUTH UMPQUA RIVER AT TILLER, OR	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	121	yes, 20 or more
Values held	1,487	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-14309000.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), South Umpqua gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-south-umpqua/

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 South Umpqua 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 confidence2025-03-17

Source: USGS — National Water Information System, USGS site 14309000, 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.