The monitoring network within this area

Hydrionis holds 428 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

428

Values held

1910–2026

Record spans

Gauges within the Upper Ocmulgee 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 OCMULGEE RIVER AT MACON, GA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1910–2025.

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	OCMULGEE RIVER AT MACON, GA (m³/s)
1910	816
1911	253
1912	1,269
1913	1,444
1914	136
1915	541
1916	1,354
1917	719
1918	405
1919	878
1921	1,048
1922	1,376
1923	801
1924	595
1925	2,053
1926	801
1927	224
1928	1,334
1929	2,078
1930	303
1932	555
1933	490
1934	481
1936	1,804
1937	943
1938	878
1939	960
1940	374
1942	2,078
1943	1,269
1944	1,422
1945	1,144
1946	1,631
1947	923
1948	680
1950	264
1951	197
1952	1,325
1953	1,087
1955	334
1956	558
1958	612
1959	779
1960	612
1961	1,365
1962	671
1963	1,090
1964	1,489
1966	1,155
1967	481
1968	657
1969	937
1970	1,186
1971	1,659
1972	963
1973	708
1974	892
1975	1,206
1976	1,189
1977	745
1978	1,048
1979	943
1980	796
1981	830
1982	688
1983	966
1984	818
1985	691
1986	294
1987	561
1988	374
1989	422
1990	1,832
1991	430
1992	580
1994	3,030
1995	810
1997	852
1998	1,858
1999	340
2000	190
2001	614
2002	273
2003	784
2004	527
2005	793
2006	286
2007	501
2008	170
2009	920
2011	345
2012	230
2013	725
2015	640
2017	504
2018	405
2019	878
2020	0
2021	360
2022	968
2023	1,393
2024	1,405
2025	648

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	1910–2025
Completeness	88.8% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	13 separate periods inside 1910–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1910 and is not continuous from it: 116 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 OCMULGEE RIVER AT MACON, GA, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1911–2025.

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	OCMULGEE RIVER AT MACON, GA (mm)
1911	277
1929	788
1930	385
1931	229
1932	378
1933	300
1934	314
1935	265
1936	724
1937	584
1938	284
1939	356
1940	319
1941	226
1942	418
1943	453
1944	464
1945	369
1946	448
1947	509
1948	675
1949	438
1950	252
1951	241
1952	392
1953	461
1954	178
1955	217
1956	323
1957	429
1958	382
1959	302
1960	403
1961	526
1962	424
1963	499
1964	813
1965	399
1966	551
1967	442
1968	369
1969	361
1970	290
1971	521
1972	406
1973	556
1974	436
1975	687
1976	495
1977	384
1978	349
1979	460
1980	458
1981	188
1982	396
1983	524
1984	503
1985	301
1986	194
1987	310
1988	203
1989	407
1990	486
1991	411
1992	489
1993	475
1994	633
1995	496
1996	441
1997	496
1998	621
1999	198
2000	183
2001	312
2002	250
2003	592
2004	401
2005	590
2006	258
2007	162
2008	190
2009	649
2010	467
2011	234
2012	132
2013	469
2014	343
2015	536
2016	389
2017	304
2018	480
2019	440
2020	680
2021	394
2022	384
2023	387
2024	504
2025	383

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	1911–2025
Completeness	85.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1911–2025 holds no value: 1912 to 1928, 17 years with no reading. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1911 and is not continuous from it: 115 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 Ocmulgee and what each holds
Gauge	Measures	Values	Record
OCMULGEE RIVER AT MACON, GA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	251	1910–2026
OCMULGEE RIVER NEAR JACKSON, GA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	177	1911–2026

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 — 03070103. 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
OCMULGEE RIVER AT MACON, GA	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
OCMULGEE RIVER NEAR JACKSON, GA	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	117	yes, 20 or more
Values held	428	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-02213000.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 Ocmulgee gauge records, accessed 2026-09-02, hydrionis.com/waters/united-states-upper-ocmulgee/

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 Ocmulgee 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 confidence2025-02-15

Source: USGS — National Water Information System, USGS site 02213000, 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.