The monitoring network within this area

Hydrionis holds 389 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

389

Values held

1886–2026

Record spans

Gauges within the Upper Alabama 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 ALABAMA RIVER AT SELMA AL

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1886–2025.

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	ALABAMA RIVER AT SELMA AL (m³/s)
1886	7,023
1891	3,851
1892	5,069
1893	3,483
1894	2,294
1895	3,313
1896	2,464
1897	3,200
1899	2,945
1900	3,625
1901	3,030
1902	3,851
1903	3,851
1904	1,719
1905	3,200
1906	3,908
1907	2,832
1908	3,285
1909	4,134
1910	2,370
1911	2,212
1912	3,766
1913	3,823
1914	1,756
1915	2,690
1916	5,012
1917	4,191
1918	6,456
1920	4,106
1921	3,398
1922	4,248
1923	2,690
1924	2,152
1925	5,380
1926	2,747
1927	2,860
1928	3,993
1929	6,230
1930	1,940
1932	2,656
1933	4,644
1934	3,058
1935	2,622
1936	5,012
1937	3,313
1938	6,173
1939	4,276
1940	2,582
1941	1,271
1942	3,483
1943	4,672
1944	4,332
1945	2,917
1946	3,936
1947	4,332
1948	3,143
1950	2,254
1951	3,936
1952	2,860
1953	3,171
1954	2,155
1955	3,483
1956	3,653
1957	4,191
1958	3,115
1959	1,640
1960	2,752
1961	8,042
1963	2,973
1964	5,635
1965	2,747
1966	3,681
1967	2,183
1968	2,512
1969	2,551
1970	3,540
1971	4,729
1972	4,248
1973	3,908
1974	2,775
1975	3,568
1976	5,040
1977	4,446
1979	7,079
1980	4,927
1981	3,313
1982	3,879
1983	4,814
1985	2,973
1986	2,237
1987	3,115
1989	4,389
1990	7,929
1991	0
1992	0
1994	0
1995	0
1996	0
1997	0
1998	0
1999	0
2000	0
2001	0
2002	0
2003	0
2004	0
2005	0
2006	0
2008	0
2009	0
2010	0
2011	0
2012	0
2013	0
2014	0
2015	0
2017	0
2018	0
2020	0
2021	0
2022	0
2023	0
2024	0
2025	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	Measured
Period held	1886–2025
Completeness	88.6% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	13 separate periods inside 1886–2025 hold no value. The longest runs from 1887 to 1890 — 4 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1886 and is not continuous from it: 140 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	2026-08-31
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 ALABAMA RIVER NEAR MONTGOMERY, AL., as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1928–2023.

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	ALABAMA RIVER NEAR MONTGOMERY, AL. (mm)
1928	540
1929	837
1930	451
1931	309
1932	681
1933	590
1934	398
1935	475
1936	721
1937	610
1938	491
1939	503
1940	433
1941	331
1942	469
1943	564
1944	598
1945	468
1946	762
1947	576
1948	732
1949	690
1950	458
1951	492
1952	506
1953	595
1954	327
1955	386
1956	429
1957	586
1958	461
1959	400
1960	436
1961	725
1962	579
1963	518
1964	768
1965	473
1966	566
1967	543
1968	479
1969	438
1970	412
1971	654
1972	571
1973	744
1974	557
1975	833
1976	670
1977	601
1978	448
1979	881
1980	730
1981	330
1982	659
1983	714
1984	581
1985	341
1986	229
1987	394
1988	268
1989	702
2002	437
2003	747
2004	500
2005	550
2008	281
2009	754
2010	459
2011	340
2012	278
2013	721
2014	523
2015	505
2016	437
2017	488
2018	625
2019	656
2020	836
2021	647
2022	553
2023	472

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	1928–2023
Completeness	85.4% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1928–2023 hold no value. The longest runs from 1990 to 2001 — 12 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1928 and is not continuous from it: 96 years separate the first value from the last, and 85% of the years between them are held. The span is not the record.
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 Upper Alabama and what each holds
Gauge	Measures	Values	Record
ALABAMA RIVER AT SELMA AL	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	225	1886–2026
ALABAMA RIVER NEAR MONTGOMERY, AL.	catchment area, annual maximum river flow, mean river flow	164	1886–2026

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 — 03150201. 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
ALABAMA RIVER AT SELMA AL	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
ALABAMA RIVER NEAR MONTGOMERY, AL.	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	141	yes, 20 or more
Values held	389	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-02423000.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 Alabama gauge records, accessed 2026-09-02, hydrionis.com/waters/united-states-upper-alabama/

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 Alabama 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 confidence2025-04-10

Source: USGS — National Water Information System, USGS site 02423000, 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.