The monitoring network within this area

Hydrionis holds 408 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

408

Values held

1931–2026

Record spans

Gauges within the Withlacoochee 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 WITHLACOOCHEE RIVER AT US 301 AT TRILBY, FL

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1931–2024.

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	WITHLACOOCHEE RIVER AT US 301 AT TRILBY, FL (m³/s)
1931	45.0
1932	10.0
1933	235
1934	250
1935	64.3
1936	38.5
1937	49.8
1939	55.8
1940	25.5
1941	50.7
1942	33.7
1943	30.3
1944	23.4
1945	80.1
1946	24.2
1947	58.0
1948	63.7
1949	60.3
1950	136
1951	17.2
1953	68.5
1955	46.7
1957	42.2
1958	73.6
1959	83.8
1960	196
1961	10.5
1962	16.7
1963	39.6
1964	85.8
1965	49.6
1966	49.6
1967	50.4
1968	43.0
1969	42.5
1970	43.3
1971	24.7
1972	14.4
1973	19.3
1974	41.1
1975	13.8
1977	5.92
1978	36.5
1979	32.0
1981	8.92
1982	30.6
1984	17.3
1985	65.7
1986	35.1
1987	93.2
1988	75.6
1990	11.1
1991	38.2
1992	8.55
1993	17.0
1994	29.2
1995	58.9
1997	15.3
1998	110
1999	3.88
2001	83.5
2002	57.5
2004	86.1
2005	37.9
2007	2.92
2008	5.92
2009	17.1
2010	24.7
2011	28.6
2012	36.0
2013	23.0
2015	52.4
2016	32.0
2017	97.7
2018	39.6
2019	34.5
2020	30.3
2021	15.7
2022	35.4
2024	42.5

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	1931–2024
Completeness	85.1% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	14 separate periods inside 1931–2024 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1931 and is not continuous from it: 94 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	2026-08-31
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 WITHLACOOCHEE RIVER AT US 301 AT TRILBY, FL, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1931–2024.

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	WITHLACOOCHEE RIVER AT US 301 AT TRILBY, FL (mm)
1931	247
1932	46.0
1933	384
1934	464
1935	192
1936	240
1937	225
1938	104
1939	224
1940	126
1941	256
1942	191
1943	139
1944	133
1945	349
1946	153
1947	308
1948	304
1949	214
1950	224
1951	197
1952	127
1953	443
1954	134
1955	147
1956	89.0
1957	227
1958	220
1959	700
1960	733
1961	69.0
1962	86.0
1963	151
1964	343
1965	168
1966	388
1967	154
1968	240
1969	267
1970	220
1971	116
1972	60.0
1973	145
1974	160
1975	97.0
1976	101
1977	46.0
1978	172
1979	307
1980	55.0
1981	25.0
1982	230
1983	272
1984	158
1985	167
1986	145
1987	171
1988	243
1989	79.0
1990	43.0
1991	133
1992	26.0
1993	78.0
1994	185
1995	276
1996	150
1997	170
1998	375
1999	19.0
2000	5.00
2001	110
2002	244
2003	496
2004	286
2005	180
2006	31.0
2007	10.0
2008	21.0
2009	71.0
2010	112
2011	78.0
2012	176
2013	102
2014	166
2015	264
2016	208
2017	244
2018	169
2019	199
2020	142
2021	114
2022	161
2023	57.0
2024	369

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	1931–2024
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1931 to 2024 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 Withlacoochee and what each holds
Gauge	Measures	Values	Record
WITHLACOOCHEE RIVER AT SR 200 NEAR HOLDER, FL	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	218	1932–2026
WITHLACOOCHEE RIVER AT US 301 AT TRILBY, FL	catchment area, annual maximum river flow, mean river flow	190	1931–2026

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 — 03100208. 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
WITHLACOOCHEE RIVER AT SR 200 NEAR HOLDER, FL	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
WITHLACOOCHEE RIVER AT US 301 AT TRILBY, FL	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	96	yes, 20 or more
Values held	408	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-02313000.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), Withlacoochee gauge records, accessed 2026-09-02, hydrionis.com/waters/united-states-withlacoochee/

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 Withlacoochee 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 confidence2024-11-01

Source: USGS — National Water Information System, USGS site 02313000, 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.