The monitoring network within this area

Hydrionis holds 844 values from 3 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

844

Values held

1920–2026

Record spans

Gauges within the Saint Croix River huc8 subbasin

3 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 Grand Lake Stream at Grand Lake Stream, Maine

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1929–2025.

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	Grand Lake Stream at Grand Lake Stream, Maine (m³/s)
1929	46.7
1930	40.5
1931	23.4
1932	41.1
1933	30.9
1934	38.5
1935	40.2
1936	47.6
1937	60.9
1938	22.7
1939	37.1
1940	39.1
1941	26.0
1942	49.0
1943	23.6
1944	33.7
1945	47.6
1946	34.0
1947	51.0
1949	28.6
1950	27.2
1951	53.5
1952	65.4
1953	54.4
1954	56.9
1955	52.1
1956	50.4
1957	18.8
1958	56.4
1959	54.4
1960	57.8
1961	58.9
1962	34.8
1963	49.0
1964	47.3
1965	20.8
1966	15.2
1967	30.3
1968	34.5
1969	34.3
1970	49.3
1971	48.1
1972	34.0
1973	56.1
1974	39.6
1975	28.0
1976	56.4
1977	39.1
1978	35.1
1979	56.1
1980	34.3
1981	32.3
1982	41.3
1983	81.3
1984	70.8
1986	33.1
1988	16.4
1989	70.2
1990	53.8
1991	39.1
1992	37.4
1993	24.3
1994	45.3
1995	16.5
1996	49.3
1997	32.0
1998	45.3
1999	32.0
2000	45.3
2001	13.1
2002	19.4
2003	26.6
2004	42.2
2005	83.0
2007	52.1
2008	68.0
2009	45.0
2010	42.5
2011	39.1
2012	27.0
2013	43.0
2014	45.0
2015	40.5
2016	36.5
2017	47.9
2018	41.9
2019	64.6
2020	27.6
2021	21.5
2022	53.8
2024	58.0
2025	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	1929–2025
Completeness	94.8% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	5 separate periods inside 1929–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1929 and is not continuous from it: 97 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	2026-10-01
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 Vanceboro, Maine, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1929–2025.

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 Vanceboro, Maine (mm)
1929	590
1930	528
1931	331
1932	591
1933	558
1934	662
1935	572
1936	746
1937	553
1938	435
1939	639
1940	530
1941	538
1942	532
1943	437
1944	438
1945	786
1946	565
1947	646
1948	379
1949	483
1950	524
1951	827
1952	693
1953	552
1954	888
1955	782
1956	449
1957	379
1958	674
1959	741
1960	761
1961	732
1962	550
1963	772
1964	614
1965	410
1966	446
1967	433
1968	645
1969	569
1970	753
1971	658
1972	479
1973	938
1974	596
1975	418
1976	803
1977	704
1978	719
1979	861
1980	496
1981	900
1982	648
1983	756
1984	911
1985	309
1986	485
1987	349
1988	473
1989	621
1990	652
1991	744
1992	641
1993	484
1994	751
1995	412
1996	828
1997	616
1998	595
1999	490
2000	736
2001	379
2002	429
2003	611
2004	523
2005	860
2006	792
2007	566
2008	814
2009	764
2010	812
2011	857
2012	692
2013	906
2014	989
2015	716
2016	700
2017	604
2018	771
2019	907
2020	637
2021	520
2022	760
2023	846
2024	658
2025	613

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	1929–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1929 to 2025 is held.
Inputs last read	2026-10-01 · when the records this was computed from were last read from their publishers
Calculation date	2026-08-24 · when the calculation method was last versioned, not a reading of any publisher
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 Saint Croix River and what each holds
Gauge	Measures	Values	Record
Grand Lake Stream at Grand Lake Stream, Maine	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	327	1929–2026
St. Croix River at Vanceboro, Maine	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	290	1929–2026
ST. CROIX RIVER NEAR BAILEYVILLE, ME	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	227	1920–2026

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 — 01050001. 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
Grand Lake Stream at Grand Lake Stream, Maine	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	2026-10-02
St. Croix River at Vanceboro, Maine	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	2026-10-02
ST. CROIX RIVER NEAR BAILEYVILLE, ME	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	2026-10-02

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 4 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	3	yes, 3 or more
Years spanned	107	yes, 20 or more
Values held	844	no
Distinct measurements	5	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-01019000.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), Saint Croix River gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-saint-croix-river/

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 Saint Croix River 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 confidence2025-05-11

Source: USGS — National Water Information System, USGS site 01019000, 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 1 October 2026.