The monitoring network within this area

Hydrionis holds 2,768 values from 4 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.

4

Gauges

2,768

Values held

1890–2026

Record spans

Gauges within the Rio Grande Headwaters huc8 subbasin

4 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 RIO GRANDE NEAR DEL NORTE, CO

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1890–2024.

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	RIO GRANDE NEAR DEL NORTE, CO (m³/s)
1890	171
1891	160
1892	133
1893	94.0
1894	101
1895	104
1896	99.4
1897	148
1898	149
1899	65.7
1900	154
1901	127
1902	50.7
1903	170
1904	57.8
1905	283
1906	217
1907	220
1908	117
1909	198
1910	149
1911	183
1913	114
1914	165
1915	133
1916	142
1917	249
1918	108
1919	170
1920	229
1921	273
1922	236
1923	148
1924	169
1925	102
1926	154
1927	425
1928	139
1929	165
1930	125
1931	75.6
1932	155
1933	143
1934	84.4
1935	185
1936	113
1937	111
1938	186
1939	101
1940	79.6
1941	225
1942	202
1943	95.7
1944	200
1945	114
1946	109
1947	124
1948	250
1949	283
1950	93.2
1951	112
1952	200
1953	118
1954	92.6
1955	122
1956	96.8
1957	202
1958	201
1959	93.7
1960	139
1961	121
1962	135
1963	89.8
1964	133
1965	176
1966	126
1967	88.9
1968	164
1969	136
1970	209
1971	89.8
1972	99.7
1973	181
1974	86.6
1975	180
1976	145
1977	49.0
1978	125
1979	227
1980	219
1981	100
1982	117
1983	164
1984	204
1985	253
1986	216
1987	212
1988	97.4
1989	103
1990	157
1991	135
1992	88.9
1993	150
1994	130
1995	210
1996	106
1997	211
1998	135
1999	151
2000	106
2001	176
2002	19.5
2003	107
2004	126
2005	214
2006	108
2007	147
2008	180
2009	171
2010	154
2011	126
2012	86.9
2013	95.1
2014	160
2015	174
2016	169
2017	133
2018	81.0
2019	227
2020	91.5
2021	121
2022	113
2023	157
2024	96.6

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	1890–2024
Completeness	99.3% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1890–2024 holds no value: 1912. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1890 and is not continuous from it: 135 years separate the first value from the last, and 99% 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 RIO GRANDE NEAR DEL NORTE, 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. 1891–2024.

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	RIO GRANDE NEAR DEL NORTE, CO (mm)
1891	312
1892	192
1893	141
1894	153
1895	234
1904	155
1905	306
1906	342
1908	205
1909	327
1910	236
1911	388
1912	293
1913	202
1914	294
1915	242
1916	336
1917	323
1918	189
1919	278
1920	361
1921	375
1922	343
1923	302
1924	278
1925	253
1926	241
1927	349
1928	244
1929	325
1930	199
1931	130
1932	320
1933	182
1934	116
1935	247
1936	170
1937	208
1938	299
1939	187
1940	113
1941	370
1942	306
1943	180
1944	307
1945	194
1946	155
1947	231
1948	328
1949	332
1950	170
1951	112
1952	298
1953	145
1954	138
1955	133
1956	120
1957	304
1958	261
1959	132
1960	217
1961	181
1962	273
1963	119
1964	134
1965	336
1966	209
1967	144
1968	241
1969	238
1970	237
1971	175
1972	172
1973	301
1974	122
1975	292
1976	214
1977	78.0
1978	147
1979	344
1980	271
1981	148
1982	252
1983	243
1984	275
1985	365
1986	373
1987	367
1988	157
1989	178
1990	190
1991	219
1992	176
1993	237
1994	195
1995	300
1996	143
1997	342
1998	209
1999	331
2000	141
2001	262
2002	56.0
2003	115
2004	190
2005	286
2006	206
2007	256
2008	256
2009	214
2010	195
2011	181
2012	147
2013	166
2014	230
2015	240
2016	241
2017	249
2018	101
2019	335
2020	136
2021	162
2022	160
2023	255
2024	177

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	1891–2024
Completeness	93.3% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1891–2024 hold no value. The longest runs from 1896 to 1903 — 8 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1891 and is not continuous from it: 134 years separate the first value from the last, and 93% 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

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

749

Fullest snowpack recorded at Middle Creek, in 1985 (mm of water)

153

Thinnest, in 2002 (mm of water)

April

Month the pack is usually at its fullest

June

Month the pack has gone by, in half of years

Peak snowpack at Middle Creek

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	Middle Creek (mm)
1981	376
1982	583
1983	434
1984	511
1985	749
1986	721
1987	747
1988	312
1989	460
1990	360
1991	474
1992	440
1993	653
1994	375
1995	684
1996	302
1997	687
1998	479
1999	589
2000	302
2001	688
2002	153
2003	329
2004	532
2005	629
2006	366
2007	442
2008	645
2009	522
2010	489
2011	429
2012	384
2013	382
2014	451
2015	323
2016	434
2017	525
2018	264
2019	637
2020	435
2021	431
2022	451
2023	615
2024	394
2025	306
2026	213

Read against the river

Middle Creek and RIO GRANDE AT THIRTYMILE BRIDGE, NR CREEDE, CO. both sit in this drainage area, and their records overlap by 16 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 Rio Grande Headwaters and what each holds
Gauge	Measures	Values	Record
RIO GRANDE NEAR DEL NORTE, CO	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	421	1890–2026
RIO GRANDE AT THIRTYMILE BRIDGE, NR CREEDE, CO.	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	275	1910–2026
SOUTH FORK RIO GRANDE AT SOUTH FORK, CO	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	268	1910–2026
NORTH CLEAR CREEK BL CONTINENTAL RESERVOIR, CO.	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	242	1929–2026

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 — 13010001. 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
RIO GRANDE NEAR DEL NORTE, 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
RIO GRANDE AT THIRTYMILE BRIDGE, NR CREEDE, 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
SOUTH FORK RIO GRANDE AT SOUTH FORK, 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
NORTH CLEAR CREEK BL CONTINENTAL RESERVOIR, 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 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	4	yes, 3 or more
Years spanned	137	yes, 20 or more
Values held	2,768	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-08220000.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), Rio Grande Headwaters gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-rio-grande-headwaters/

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 Rio Grande Headwaters 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 confidence2024-05-21

Source: USGS — National Water Information System, USGS site 08220000, 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.