The monitoring network within this area

Hydrionis holds 362 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

362

Values held

1902–2026

Record spans

Gauges within the Lower St. Croix 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 ST. CROIX RIVER AT ST. CROIX FALLS, WI

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1940–2025.

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	ST. CROIX RIVER AT ST. CROIX FALLS, WI (m³/s)
1940	405
1941	838
1942	527
1943	807
1944	1,051
1945	1,263
1946	1,005
1947	521
1948	524
1949	674
1950	1,555
1951	954
1952	1,218
1953	923
1954	1,257
1955	623
1956	895
1957	731
1958	799
1959	411
1960	473
1961	779
1962	852
1963	297
1964	784
1965	1,294
1966	1,008
1967	951
1968	558
1969	1,178
1970	566
1971	974
1972	1,237
1973	711
1974	736
1975	968
1976	1,008
1977	442
1978	756
1979	974
1980	379
1981	725
1982	866
1983	671
1984	1,002
1985	782
1986	1,048
1988	328
1989	513
1990	450
1991	716
1992	640
1993	586
1994	603
1995	883
1996	1,017
1997	1,175
1998	504
1999	419
2000	377
2001	1,724
2002	920
2003	640
2004	614
2005	881
2007	436
2008	699
2009	671
2010	631
2012	1,053
2013	549
2014	932
2015	340
2016	1,484
2017	501
2018	994
2019	756
2021	524
2022	745
2023	1,472
2024	651
2025	289

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	1940–2025
Completeness	95.3% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	4 separate periods inside 1940–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1940 and is not continuous from it: 86 years separate the first value from the last, and 95% 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 ST. CROIX RIVER AT ST. CROIX FALLS, WI, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1902–2025.

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	ST. CROIX RIVER AT ST. CROIX FALLS, WI (mm)
1902	177
1904	287
1910	133
1911	134
1912	163
1913	171
1914	206
1915	217
1916	317
1917	180
1918	139
1919	202
1920	263
1921	145
1922	182
1923	135
1924	152
1925	110
1926	147
1927	242
1928	253
1929	198
1930	148
1931	137
1932	132
1933	108
1934	105
1935	186
1936	204
1937	175
1938	270
1939	227
1940	154
1941	320
1942	239
1943	285
1944	348
1945	346
1946	306
1947	212
1948	179
1949	176
1950	300
1951	379
1952	348
1953	357
1954	373
1955	268
1956	252
1957	261
1958	199
1959	163
1960	207
1961	187
1962	231
1963	152
1964	187
1965	332
1966	277
1967	246
1968	318
1969	261
1970	220
1971	298
1972	366
1973	305
1974	255
1975	305
1976	207
1977	212
1978	276
1979	298
1980	163
1981	257
1982	319
1983	354
1984	387
1985	352
1986	464
1987	154
1988	153
1989	188
1990	207
1991	337
1992	269
1993	276
1994	282
1995	337
1996	343
1997	272
1998	207
1999	246
2000	193
2001	337
2002	332
2003	267
2004	259
2005	274
2006	181
2007	188
2008	251
2009	193
2010	284
2011	315
2012	254
2013	235
2014	420
2015	280
2016	382
2017	344
2018	341
2019	450
2020	310
2021	224
2022	248
2023	287
2024	267
2025	177

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	1902–2025
Completeness	95.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1902–2025 hold no value. The longest runs from 1905 to 1909 — 5 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1902 and is not continuous from it: 124 years separate the first value from the last, and 95% 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 Lower St. Croix and what each holds
Gauge	Measures	Values	Record
ST. CROIX RIVER AT ST. CROIX FALLS, WI	burned area within 50 km, catchment area, annual maximum river flow, mean river flow	241	1902–2026
APPLE RIVER NEAR SOMERSET, WI	burned area within 50 km, catchment area, mean river flow	121	1915–2026

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 — 07030005. 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
ST. CROIX RIVER AT ST. CROIX FALLS, WI	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
APPLE RIVER NEAR SOMERSET, WI	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	125	yes, 20 or more
Values held	362	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-05340500.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), Lower St. Croix gauge records, accessed 2026-09-02, hydrionis.com/waters/united-states-lower-st-croix/

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 Lower St. Croix 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 confidence2025-05-04

Source: USGS — National Water Information System, USGS site 05340500, 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.