The monitoring network within this area

Hydrionis holds 2,586 values from 10 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.

10

Gauges

2,586

Values held

1896–2026

Record spans

Gauges within the Upper South Platte huc8 subbasin

10 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 BEAR CREEK AT MORRISON, CO

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1896–2007.

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	BEAR CREEK AT MORRISON, CO (m³/s)
1896	244
1897	33.4
1901	6.06
1920	10.2
1922	9.91
1923	30.3
1924	13.6
1925	16.7
1926	16.7
1927	11.0
1928	8.64
1929	44.2
1930	21.0
1931	7.65
1932	8.55
1933	230
1934	131
1935	30.0
1936	21.1
1937	11.1
1938	176
1940	17.4
1941	70.8
1942	52.4
1943	6.91
1944	15.3
1945	10.6
1946	4.30
1947	10.9
1948	11.3
1949	35.4
1950	7.48
1951	6.74
1952	12.9
1953	12.6
1954	12.6
1955	48.1
1956	9.85
1957	46.4
1958	11.9
1959	4.16
1960	5.89
1961	7.14
1962	4.30
1963	5.66
1964	8.10
1965	29.2
1966	2.32
1967	4.39
1968	3.71
1969	66.3
1970	17.2
1971	4.93
1972	6.43
1973	41.9
1974	4.84
1975	7.08
1976	3.94
1977	3.85
1978	3.03
1979	15.0
1980	20.6
1981	6.65
1982	5.47
1983	117
1984	16.3
1985	8.98
1986	7.36
1987	12.3
1988	7.16
1989	3.11
1990	10.7
1991	8.44
1992	4.84
1993	3.85
1994	3.60
1995	25.3
1996	4.70
1997	13.7
1998	23.6
1999	25.8
2000	3.45
2001	4.93
2002	1.42
2003	8.83
2004	5.86
2005	8.16
2006	6.85
2007	10.6

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	1896–2007
Completeness	79.5% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	4 separate periods inside 1896–2007 hold no value. The longest runs from 1902 to 1919 — 18 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1896 and is not continuous from it: 112 years separate the first value from the last, and 79% 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 SOUTH PLATTE RIVER AT SOUTH PLATTE, 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. 1896–2006.

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	SOUTH PLATTE RIVER AT SOUTH PLATTE, CO (mm)
1896	32.0
1899	60.0
1902	14.0
1903	29.0
1904	36.0
1905	53.0
1906	53.0
1907	60.0
1908	24.0
1909	76.0
1910	40.0
1911	35.0
1912	57.0
1913	52.0
1914	124
1915	61.0
1916	43.0
1917	58.0
1918	58.0
1919	66.0
1920	59.0
1921	107
1922	51.0
1923	68.0
1924	64.0
1925	36.0
1926	63.0
1927	42.0
1928	44.0
1929	48.0
1930	55.0
1931	41.0
1932	36.0
1933	50.0
1934	28.0
1935	36.0
1936	55.0
1937	32.0
1938	58.0
1939	37.0
1940	24.0
1941	51.0
1942	111
1943	34.0
1944	42.0
1945	48.0
1946	35.0
1947	65.0
1948	71.0
1949	79.0
1950	32.0
1951	35.0
1952	40.0
1953	37.0
1954	30.0
1955	30.0
1956	27.0
1957	54.0
1958	44.0
1959	29.0
1960	34.0
1961	42.0
1962	46.0
1963	30.0
1964	37.0
1965	53.0
1966	35.0
1967	36.0
1968	43.0
1969	69.0
1970	100
1971	49.0
1972	45.0
1973	88.0
1974	48.0
1975	54.0
1976	54.0
1977	45.0
1978	47.0
1979	57.0
1980	87.0
1981	45.0
2002	52.0
2003	44.0
2004	45.0
2005	52.0
2006	61.0

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	1896–2006
Completeness	78.4% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	3 separate periods inside 1896–2006 hold no value. The longest runs from 1982 to 2001 — 20 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1896 and is not continuous from it: 111 years separate the first value from the last, and 78% 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

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

333

Fullest snowpack recorded at Echo Lake, in 2007 (mm of water)

47

Thinnest, in 2026 (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 Echo Lake

Water years 1999–2026. 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	Echo Lake (mm)
1999	276
2000	212
2001	170
2002	76.0
2003	315
2004	212
2005	223
2006	161
2007	333
2008	207
2009	154
2010	190
2011	181
2012	130
2013	160
2014	226
2015	297
2016	250
2017	212
2018	116
2019	216
2020	207
2021	227
2022	153
2023	166
2024	238
2025	179
2026	47.0

Why the snow is not read against the river here

Peak snow water equivalent and Mean river flow, water year overlap for only 7 years at these subjects. A relationship read off a span that short is reading the weather of a few seasons.

Every gauge Hydrionis holds within this area

Gauges within the Upper South Platte and what each holds
Gauge	Measures	Values	Record
BEAR CREEK AT MORRISON, CO	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	302	1896–2026
SOUTH PLATTE RIVER AT SOUTH PLATTE, CO	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	294	1896–2026
BEAR CREEK AT MOUTH AT SHERIDAN, CO	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	275	1927–2026
SOUTH PLATTE RIVER BELOW CHEESMAN LAKE, CO	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	272	1924–2026
NF SOUTH PLATTE RIVER AT SOUTH PLATTE, CO.	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	245	1909–2026
NF SOUTH PLATTE R BELOW GENEVA C, AT GRANT, CO.	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	215	1909–2026
SOUTH PLATTE RIVER AT WATERTON, CO.	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	198	1926–2026
GOOSE CREEK ABOVE CHEESMAN LAKE, CO.	catchment area, annual maximum river flow	57	1925–2026
SOUTH PLATTE RIVER ABOVE CHEESMAN LAKE, CO.	catchment area, annual maximum river flow	43	1925–2026
GENEVA CREEK AT GRANT, CO.	catchment area, annual maximum river flow	13	1909–2026

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 — 10190002. 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
BEAR CREEK AT MORRISON, 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 PLATTE RIVER AT SOUTH PLATTE, 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
BEAR CREEK AT MOUTH AT SHERIDAN, 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 PLATTE RIVER BELOW CHEESMAN LAKE, 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
NF SOUTH PLATTE RIVER AT SOUTH PLATTE, 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
NF SOUTH PLATTE R BELOW GENEVA C, AT GRANT, 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 PLATTE RIVER AT WATERTON, 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
GOOSE CREEK ABOVE CHEESMAN LAKE, 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 PLATTE RIVER ABOVE CHEESMAN LAKE, 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
GENEVA CREEK AT GRANT, 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	8	yes, 3 or more
Years spanned	131	yes, 20 or more
Values held	2,586	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-06710500.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 South Platte gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-upper-south-platte/

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 South Platte 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 confidence2007-05-10

Source: USGS — National Water Information System, USGS site 06710500, 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.