The monitoring network within this area

Hydrionis holds 477 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

477

Values held

1891–2026

Record spans

Gauges within the Middle Gila 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 GILA RIVER AT KELVIN, AZ.

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1891–2016.

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	GILA RIVER AT KELVIN, AZ. (m³/s)
1891	2,888
1905	5,380
1912	991
1913	125
1914	510
1916	3,738
1918	428
1919	589
1921	680
1922	213
1923	331
1925	317
1926	2,322
1927	243
1928	340
1929	328
1930	1,212
1931	810
1932	362
1933	249
1934	191
1935	595
1936	357
1937	289
1938	160
1939	264
1940	1,082
1942	93.4
1943	178
1944	793
1945	261
1946	182
1947	283
1948	166
1949	159
1950	196
1951	374
1952	154
1953	119
1954	504
1955	279
1956	51.0
1957	129
1958	150
1959	168
1961	272
1963	167
1964	118
1965	141
1967	119
1969	164
1970	187
1971	88.3
1972	292
1974	110
1975	75.0
1976	71.1
1977	69.4
1978	765
1980	197
1981	94.0
1982	100.0
1983	127
1984	174
1986	121
1987	47.3
1988	116
1989	48.7
1990	145
1991	314
1992	146
1993	2,121
1994	56.9
1995	558
1996	67.1
1997	30.0
1998	43.6
1999	48.4
2000	33.7
2002	47.0
2003	58.6
2004	38.8
2005	199
2006	569
2007	77.3
2008	172
2009	20.8
2010	157
2011	27.0
2012	32.0
2013	23.1
2014	53.2
2015	45.6
2016	33.1

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	1891–2016
Completeness	74.6% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	15 separate periods inside 1891–2016 hold no value. The longest runs from 1892 to 1904 — 13 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: 126 years separate the first value from the last, and 75% of the years between them are held. The span is not the record.
Last read from the publisher	2026-08-31
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 GILA RIVER AT KELVIN, 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. 1912–2025.

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	GILA RIVER AT KELVIN, AZ. (mm)
1912	12.0
1913	6.00
1914	33.0
1915	37.0
1916	43.0
1917	9.00
1918	5.00
1919	23.0
1920	15.0
1921	12.0
1922	3.00
1923	13.0
1924	6.00
1925	6.00
1926	11.0
1927	8.00
1928	4.00
1929	3.00
1930	9.00
1931	10.0
1932	9.00
1933	10.0
1934	5.00
1935	9.00
1936	8.00
1937	10.0
1938	5.00
1939	5.00
1940	7.00
1941	12.0
1942	10.0
1943	11.0
1944	9.00
1945	6.00
1946	3.00
1947	2.00
1948	2.00
1949	8.00
1950	4.00
1951	2.00
1952	7.00
1953	2.00
1954	6.00
1955	6.00
1956	2.00
1957	3.00
1958	8.00
1959	5.00
1960	8.00
1961	2.00
1962	7.00
1963	6.00
1964	4.00
1965	6.00
1966	9.00
1967	10.0
1968	9.00
1969	9.00
1970	7.00
1971	3.00
1972	6.00
1973	10.0
1974	10.0
1975	9.00
1976	5.00
1977	3.00
1978	11.0
1979	17.0
1980	18.0
1981	14.0
1982	8.00
1983	20.0
1984	15.0
1985	23.0
1986	12.0
1987	12.0
1988	12.0
1989	11.0
1990	2.00
1991	10.0
1992	17.0
1993	63.0
1994	13.0
1995	15.0
1996	12.0
1997	8.00
1998	9.00
1999	3.00
2000	3.00
2001	7.00
2002	1.00
2003	2.00
2004	2.00
2005	9.00
2006	8.00
2007	7.00
2008	8.00
2009	6.00
2010	9.00
2011	4.00
2012	1.00
2013	2.00
2014	4.00
2015	5.00
2016	4.00
2017	7.00
2018	2.00
2019	5.00
2020	5.00
2021	2.00
2022	4.00
2023	8.00
2024	6.00
2025	5.00

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	1912–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1912 to 2025 is held.
Last read from the publisher	2026-08-24
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 Middle Gila and what each holds
Gauge	Measures	Values	Record
GILA RIVER AT KELVIN, AZ.	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	258	1891–2026
GILA RIVER BELOW COOLIDGE DAM, AZ.	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	219	1901–2026

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 — 15050100. 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
GILA RIVER AT KELVIN, 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	2026-08-26
GILA RIVER BELOW COOLIDGE DAM, 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	2026-08-26

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	136	yes, 20 or more
Values held	477	no
Distinct measurements	4	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-09474000.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), Middle Gila gauge records, accessed 2026-09-02, hydrionis.com/waters/united-states-middle-gila/

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 Middle Gila 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 confidence2016-08-12

Source: USGS — National Water Information System, USGS site 09474000, 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 31 August 2026.