The monitoring network within this area

Hydrionis holds 422 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

422

Values held

1918–2026

Record spans

Gauges within the Pickwick Lake 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 TENNESSEE RIVER AT FLORENCE AL

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1918–2015.

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	TENNESSEE RIVER AT FLORENCE AL (m³/s)
1918	7,815
1919	6,683
1920	8,495
1921	6,315
1922	7,589
1923	6,088
1924	5,550
1925	4,106
1926	4,219
1928	6,145
1929	8,297
1931	4,134
1932	6,909
1933	7,702
1934	7,532
1935	5,890
1936	8,863
1937	6,994
1938	5,239
1939	8,099
1940	3,341
1941	3,058
1942	3,908
1943	7,759
1944	8,608
1945	7,419
1946	10,052
1947	9,656
1948	11,185
1949	9,741
1950	8,155
1951	8,580
1953	5,720
1954	8,807
1955	9,231
1956	8,155
1957	10,392
1959	4,587
1960	4,332
1961	6,796
1962	8,495
1963	9,599
1964	7,985
1965	9,656
1966	4,842
1967	4,644
1968	7,362
1969	7,561
1970	7,079
1971	5,550
1972	4,842
1973	15,008
1974	9,260
1975	9,656
1977	7,136
1978	6,400
1979	6,711
1980	9,514
1981	2,809
1982	6,626
1983	7,730
1984	9,599
1985	4,502
1986	2,860
1987	6,881
1988	4,021
1989	7,561
1990	12,459
1991	9,401
1993	6,286
1994	10,307
1995	5,125
1996	5,522
1997	7,249
1998	6,371
1999	6,088
2000	6,938
2001	5,833
2002	8,495
2003	10,336
2004	6,400
2006	0
2007	0
2008	0
2009	7,787
2010	0
2011	0
2012	0
2013	7,617
2014	0
2015	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	1918–2015
Completeness	92.9% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	7 separate periods inside 1918–2015 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1918 and is not continuous from it: 98 years separate the first value from the last, and 93% 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 SHOAL CREEK AT IRON CITY, TN, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1926–2025.

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	SHOAL CREEK AT IRON CITY, TN (mm)
1926	582
1927	723
1928	652
1929	876
1930	537
1931	432
1932	966
1933	778
1934	374
1935	552
1936	527
1937	751
1938	505
1939	785
1940	451
1941	276
1942	343
1943	286
1944	736
1945	847
1946	635
1947	526
1948	791
1949	698
1950	1,046
1951	863
1952	559
1953	650
1954	429
1955	684
1956	508
1957	759
1958	490
1959	569
1960	510
1961	632
1962	674
1963	382
1964	666
1965	591
1966	422
1967	618
1968	546
1969	534
1970	612
1971	626
1972	764
1973	1,066
1974	998
1975	1,007
1976	602
1977	793
1978	579
1979	1,017
1980	828
1981	303
1982	673
1983	870
1984	648
1985	407
1986	497
1987	383
1988	357
1989	881
1990	719
1991	1,176
1992	566
1993	534
2001	731
2002	790
2003	762
2004	951
2005	464
2006	488
2007	271
2008	489
2009	748
2010	601
2011	688
2012	478
2013	563
2014	505
2015	548
2016	417
2017	456
2018	790
2019	919
2020	1,024
2021	864
2022	721
2023	519
2024	520
2025	602

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	1926–2025
Completeness	93.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1926–2025 holds no value: 1994 to 2000, 7 years with no reading. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1926 and is not continuous from it: 100 years separate the first value from the last, and 93% 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 Pickwick Lake and what each holds
Gauge	Measures	Values	Record
SHOAL CREEK AT IRON CITY, TN	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	224	1925–2026
TENNESSEE RIVER AT FLORENCE AL	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	198	1918–2026

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 — 06030005. 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
SHOAL CREEK AT IRON CITY, TN	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
TENNESSEE RIVER AT FLORENCE 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	109	yes, 20 or more
Values held	422	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-03588500.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), Pickwick Lake gauge records, accessed 2026-09-02, hydrionis.com/waters/united-states-pickwick-lake/

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 Pickwick Lake 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 confidence2025-03-16

Source: USGS — National Water Information System, USGS site 03588500, 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.