The monitoring network within this area

Hydrionis holds 387 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

387

Values held

1904–2026

Record spans

Gauges within the Middle Chattahoochee-Lake Harding 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 CHATTAHOOCHEE RIVER AT WEST POINT, GA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1906–2025.

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	CHATTAHOOCHEE RIVER AT WEST POINT, GA (m³/s)
1906	1,467
1907	864
1908	1,155
1909	1,458
1910	654
1911	586
1912	2,078
1913	1,328
1914	524
1916	1,826
1917	1,455
1919	3,794
1921	1,501
1922	1,552
1923	1,116
1924	719
1925	2,557
1926	807
1927	682
1928	864
1929	2,481
1930	875
1932	827
1934	983
1936	2,135
1937	1,413
1938	1,809
1939	1,288
1940	810
1941	391
1942	1,818
1943	1,818
1944	1,308
1945	1,860
1946	1,691
1947	1,337
1948	929
1950	453
1951	476
1952	1,223
1953	739
1954	731
1955	680
1956	1,158
1957	1,325
1958	963
1959	765
1960	816
1961	2,673
1962	994
1964	1,566
1965	1,093
1966	1,158
1967	833
1968	858
1969	1,235
1970	1,337
1971	1,640
1972	1,625
1973	1,059
1974	810
1975	1,328
1976	980
1977	745
1979	1,184
1980	722
1981	547
1982	810
1983	697
1985	535
1987	490
1988	496
1989	821
1990	1,580
1991	606
1992	1,025
1994	1,124
1995	561
1996	1,124
1997	1,252
1998	1,405
1999	518
2000	498
2001	861
2002	487
2003	2,127
2004	646
2005	1,042
2006	428
2008	470
2009	1,549
2011	555
2012	564
2013	773
2014	586
2015	473
2017	793
2018	569
2020	926
2021	1,161
2022	900
2023	1,337
2024	1,136
2025	940

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	1906–2025
Completeness	86.7% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	16 separate periods inside 1906–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1906 and is not continuous from it: 120 years separate the first value from the last, and 87% 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 SWEETWATER CREEK NEAR AUSTELL, 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. 1905–2025.

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	SWEETWATER CREEK NEAR AUSTELL, GA (mm)
1905	525
1938	385
1939	420
1940	425
1941	297
1942	427
1943	452
1944	435
1945	458
1946	648
1947	453
1948	706
1949	585
1950	388
1951	392
1952	379
1953	435
1954	228
1955	231
1956	292
1957	408
1958	449
1959	364
1960	422
1961	667
1962	497
1963	581
1964	863
1965	504
1966	527
1967	573
1968	486
1969	412
1970	359
1971	578
1972	578
1973	713
1974	535
1975	711
1976	587
1977	573
1978	395
1979	608
1980	537
1981	304
1982	654
1983	660
1984	656
1985	433
1986	210
1987	376
1988	210
1989	592
1990	647
1991	629
1992	597
1993	478
1994	576
1995	587
1996	593
1997	647
1998	625
1999	288
2000	291
2001	387
2002	498
2003	758
2004	589
2005	614
2006	443
2007	187
2008	267
2009	897
2010	470
2011	303
2012	172
2013	560
2014	396
2015	496
2016	305
2017	340
2018	619
2019	465
2020	714
2021	559
2022	459
2023	470
2024	475
2025	361

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	1905–2025
Completeness	73.6% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1905–2025 holds no value: 1906 to 1937, 32 years with no reading. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1905 and is not continuous from it: 121 years separate the first value from the last, and 74% 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 Middle Chattahoochee-Lake Harding and what each holds
Gauge	Measures	Values	Record
SWEETWATER CREEK NEAR AUSTELL, GA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	218	1904–2026
CHATTAHOOCHEE RIVER AT WEST POINT, GA	catchment area, annual maximum river flow, mean river flow	169	1906–2026

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 — 03130002. 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
SWEETWATER CREEK NEAR AUSTELL, 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
CHATTAHOOCHEE RIVER AT WEST POINT, 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	123	yes, 20 or more
Values held	387	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-02337000.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 Chattahoochee-Lake Harding gauge records, accessed 2026-09-02, hydrionis.com/waters/united-states-middle-chattahoochee-lake-harding/

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 Chattahoochee-Lake Harding 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 confidence2025-02-14

Source: USGS — National Water Information System, USGS site 02337000, 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.