The monitoring network within this area

Hydrionis holds 896 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

896

Values held

1903–2026

Record spans

Gauges within the Uncompahgre 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 UNCOMPAHGRE RIVER AT COLONA, CO

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1903–2025.

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	UNCOMPAHGRE RIVER AT COLONA, CO (m³/s)
1903	52.4
1904	38.2
1905	56.1
1922	45.6
1923	48.7
1924	52.1
1925	43.6
1926	56.6
1927	96.3
1928	57.8
1929	82.7
1930	54.9
1931	27.1
1932	45.9
1933	53.8
1934	25.9
1935	49.6
1936	32.0
1937	63.4
1938	96.0
1939	30.0
1940	52.4
1941	71.9
1942	70.5
1943	39.6
1944	63.4
1945	52.1
1946	37.7
1947	50.7
1948	54.7
1949	81.0
1950	35.7
1951	28.2
1952	75.9
1953	72.8
1954	17.6
1955	48.1
1956	35.1
1957	93.4
1958	68.0
1959	43.6
1960	46.2
1961	37.4
1962	37.7
1963	31.7
1964	56.1
1965	52.4
1966	28.9
1967	28.0
1968	59.5
1969	36.2
1970	75.3
1971	43.0
1972	29.2
1973	90.6
1974	28.9
1975	95.1
1976	25.8
1977	15.8
1978	52.4
1979	51.3
1980	46.4
1981	39.1
1982	66.3
1983	98.0
1984	110
1985	64.8
1986	50.1
1987	48.4
1988	19.8
1989	13.9
1990	49.3
1991	29.2
1992	23.4
1993	38.5
1994	28.6
1995	63.1
1996	25.9
1997	56.1
1998	25.1
1999	49.3
2000	34.5
2001	20.8
2002	10.5
2003	49.3
2004	24.5
2005	41.1
2006	23.1
2007	29.2
2008	40.2
2009	58.3
2010	66.8
2011	40.2
2012	14.1
2013	18.6
2014	33.4
2015	46.2
2016	41.1
2017	37.9
2018	13.3
2019	45.6
2020	17.4
2021	16.3
2022	25.4
2023	26.1
2024	37.7
2025	17.3

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	1903–2025
Completeness	87.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1903–2025 holds no value: 1906 to 1921, 16 years with no reading. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1903 and is not continuous from it: 123 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 DALLAS CREEK NEAR RIDGWAY, CO, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1923–2025.

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	DALLAS CREEK NEAR RIDGWAY, CO (mm)
1923	166
1924	214
1925	199
1926	172
1956	60.0
1957	207
1958	159
1959	71.0
1960	86.0
1961	110
1962	99.0
1963	73.0
1964	122
1965	212
1966	90.0
1967	61.0
1968	93.0
1969	108
1970	175
1980	106
1981	77.0
1982	177
1983	248
1984	324
1985	264
1986	181
1987	209
1988	106
1989	59.0
1990	59.0
1991	102
1992	126
1993	122
1994	96.0
1995	245
1996	89.0
1997	234
1998	114
1999	177
2000	92.0
2001	84.0
2002	55.0
2003	92.0
2004	82.0
2005	130
2006	88.0
2007	138
2008	184
2009	127
2010	126
2011	129
2012	66.0
2013	84.0
2014	136
2015	118
2016	139
2017	139
2018	28.0
2019	137
2020	38.0
2021	69.0
2022	84.0
2023	145
2024	94.0
2025	65.0

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	1923–2025
Completeness	63.1% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1923–2025 hold no value. The longest runs from 1927 to 1955 — 29 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1923 and is not continuous from it: 103 years separate the first value from the last, and 63% 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.

604

Fullest snowpack recorded at Idarado, in 1984 (mm of water)

140

Thinnest, in 2026 (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 Idarado

Water years 1981–2026. 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	Idarado (mm)
1981	228
1982	382
1983	496
1984	604
1985	342
1986	297
1987	386
1988	202
1989	348
1990	205
1991	289
1992	357
1993	407
1994	263
1995	413
1996	390
1997	556
1998	348
1999	256
2000	296
2001	251
2002	202
2003	279
2004	303
2005	373
2006	293
2007	252
2008	429
2009	346
2010	316
2011	375
2012	256
2013	237
2014	306
2015	298
2016	342
2017	384
2018	203
2019	446
2020	288
2021	287
2022	259
2023	430
2024	253
2025	297
2026	140

Read against the river

Idarado and DALLAS CREEK NEAR RIDGWAY, CO both sit in this drainage area, and their records overlap by 44 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 Uncompahgre and what each holds
Gauge	Measures	Values	Record
DALLAS CREEK NEAR RIDGWAY, CO	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	234	1922–2026
UNCOMPAHGRE RIVER AT COLONA, CO	catchment area, annual maximum river flow	108	1903–2026

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 — 14020006. 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
DALLAS CREEK NEAR RIDGWAY, CO	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
UNCOMPAHGRE RIVER AT COLONA, CO	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 3 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	2	no
Years spanned	124	yes, 20 or more
Values held	896	no
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-09147000.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), Uncompahgre gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-uncompahgre/

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 Uncompahgre 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 confidence2025-07-03

Source: USGS — National Water Information System, USGS site 09147000, 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.