The monitoring network within this area

Hydrionis holds 433 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.

Gauges

433

Values held

1913–2026

Record spans

Gauges within the Upper Santa Cruz 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 SANTA CRUZ RIVER AT TUCSON, AZ

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1914–2025.

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	SANTA CRUZ RIVER AT TUCSON, AZ (m³/s)
1914	425
1916	142
1917	212
1918	139
1919	133
1920	55.2
1921	113
1922	56.6
1923	53.8
1925	96.3
1926	323
1927	55.2
1928	45.3
1929	294
1930	50.1
1931	261
1932	119
1933	173
1934	170
1935	292
1936	153
1937	92.9
1938	255
1939	227
1940	320
1941	70.5
1942	47.3
1943	128
1944	185
1945	306
1946	121
1948	109
1949	108
1950	269
1951	142
1952	108
1953	167
1954	271
1955	309
1956	73.9
1957	86.4
1958	180
1959	125
1960	174
1961	470
1962	141
1963	132
1964	368
1965	33.7
1966	156
1967	166
1969	247
1970	242
1971	227
1972	98.3
1974	225
1975	70.2
1976	201
1977	75.3
1978	382
1980	78.2
1981	76.5
1983	1,492
1984	283
1986	54.4
1987	42.5
1988	303
1990	267
1991	60.3
1992	169
1993	1,059
1994	138
1995	16.3
1996	265
1998	169
1999	165
2000	206
2002	160
2003	136
2004	94.3
2005	462
2006	204
2007	374
2008	127
2009	127
2010	323
2011	280
2012	45.9
2013	35.1
2014	379
2015	133
2016	152
2017	146
2018	160
2020	15.1
2021	144
2022	28.6
2023	30.9
2024	83.5
2025	31.7

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	1914–2025
Completeness	89.3% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	12 separate periods inside 1914–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1914 and is not continuous from it: 112 years separate the first value from the last, and 89% 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 SANTA CRUZ RIVER NEAR NOGALES, AZ., as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1917–2024.

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	SANTA CRUZ RIVER NEAR NOGALES, AZ. (mm)
1917	13.0
1918	2.00
1919	16.0
1931	40.0
1932	25.0
1933	5.00
1936	11.0
1937	15.0
1938	6.00
1939	18.0
1940	7.00
1941	6.00
1942	7.00
1943	9.00
1944	3.00
1945	4.00
1946	15.0
1947	4.00
1948	8.00
1949	13.0
1950	17.0
1951	4.00
1952	5.00
1953	4.00
1954	28.0
1955	51.0
1956	4.00
1957	5.00
1958	20.0
1959	14.0
1960	21.0
1961	11.0
1962	8.00
1963	15.0
1964	26.0
1965	21.0
1966	46.0
1967	32.0
1968	14.0
1969	12.0
1970	10.0
1971	19.0
1972	3.00
1973	17.0
1974	15.0
1975	19.0
1976	14.0
1977	56.0
1978	55.0
1979	43.0
1980	2.00
1981	9.00
1982	8.00
1983	78.0
1984	71.0
1985	56.0
1986	15.0
1987	6.00
1988	11.0
1989	5.00
1990	15.0
1991	19.0
1992	21.0
1993	37.0
1994	11.0
1995	13.0
1996	1.00
1997	1.00
1998	7.00
1999	8.00
2000	31.0
2001	6.00
2002	1.00
2003	1.00
2004	0
2005	3.00
2006	7.00
2007	4.00
2008	2.00
2009	0
2010	12.0
2011	1.00
2012	2.00
2013	1.00
2014	13.0
2015	2.00
2016	1.00
2017	8.00
2018	0
2019	5.00
2020	3.00
2021	4.00
2022	12.0
2023	1.00
2024	2.00

About this series

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	1917–2024
Completeness	88.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1917–2024 hold no value. The longest runs from 1920 to 1930 — 11 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1917 and is not continuous from it: 108 years separate the first value from the last, and 88% 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

Every gauge Hydrionis holds within this area

Gauges within the Upper Santa Cruz and what each holds
Gauge	Measures	Values	Record
SANTA CRUZ RIVER NEAR NOGALES, AZ.	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	324	1913–2026
SANTA CRUZ RIVER AT TUCSON, AZ	catchment area, annual maximum river flow	109	1914–2026

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 — 15050301. 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
SANTA CRUZ RIVER NEAR NOGALES, AZ.	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
SANTA CRUZ RIVER AT TUCSON, AZ	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	114	yes, 20 or more
Values held	433	no
Distinct measurements	5	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-09480500.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 Santa Cruz gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-upper-santa-cruz/

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 Santa Cruz 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 confidence2025-09-26

Source: USGS — National Water Information System, USGS site 09480500, 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.