The monitoring network within this area

Hydrionis holds 34,085 values from 4 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.

4
Gauges
34,085
Values held
1963–2026
Record spans
Gauges within the Porvoonjoki drainage basin
4 monitoring points, positioned as the publisher records them.
Gauges within the Porvoonjoki drainage basinKukonkoski, Patomäenkoski, Strömsberg, VakkolaKukonkoskiPatomäenkoskiStrömsbergVakkola

How low, how high and how variable this gauge runs

A hydrograph says what happened; these say how often. Read off Vakkola's whole daily record between 1963 and 2026, they describe the shape of the record rather than any day in it — and they belong to this gauge and its reach, not to this drainage area.

1.400 m³/s
Q95 low flow
5.370 m³/s
Q50 median flow
28.000 m³/s
Q10 high flow
Largest day of each water year at Vakkola
The highest daily mean discharge in each October-to-September water year, 1963–2025.
Largest day of each water year at VakkolaLargest day of each water year at Vakkola: Vakkola in m³/s, from 1963 to 2025.0100200m³/s19631971197919871995200320112019Vakkola 1963: 78.0 m³/sVakkola 1964: 89.0 m³/sVakkola 1965: 203 m³/sVakkola 1966: 106 m³/sVakkola 1967: 77.0 m³/sVakkola 1968: 109 m³/sVakkola 1969: 105 m³/sVakkola 1970: 82.0 m³/sVakkola 1971: 101 m³/sVakkola 1972: 43.0 m³/sVakkola 1973: 100 m³/sVakkola 1974: 94.0 m³/sVakkola 1975: 82.0 m³/sVakkola 1976: 93.0 m³/sVakkola 1977: 57.0 m³/sVakkola 1978: 69.0 m³/sVakkola 1979: 52.0 m³/sVakkola 1980: 118 m³/sVakkola 1981: 80.0 m³/sVakkola 1982: 80.0 m³/sVakkola 1983: 158 m³/sVakkola 1984: 94.0 m³/sVakkola 1985: 81.0 m³/sVakkola 1986: 77.0 m³/sVakkola 1987: 92.0 m³/sVakkola 1988: 73.0 m³/sVakkola 1989: 78.0 m³/sVakkola 1990: 90.0 m³/sVakkola 1991: 64.0 m³/sVakkola 1992: 63.0 m³/sVakkola 1993: 109 m³/sVakkola 1994: 81.0 m³/sVakkola 1995: 83.0 m³/sVakkola 1996: 48.0 m³/sVakkola 1997: 53.0 m³/sVakkola 1998: 116 m³/sVakkola 1999: 68.0 m³/sVakkola 2000: 60.0 m³/sVakkola 2001: 55.0 m³/sVakkola 2002: 38.0 m³/sVakkola 2003: 99.0 m³/sVakkola 2004: 63.0 m³/sVakkola 2005: 69.0 m³/sVakkola 2006: 59.0 m³/sVakkola 2007: 70.0 m³/sVakkola 2008: 59.0 m³/sVakkola 2009: 92.4 m³/sVakkola 2010: 92.0 m³/sVakkola 2011: 69.0 m³/sVakkola 2012: 96.0 m³/sVakkola 2013: 45.0 m³/sVakkola 2014: 61.0 m³/sVakkola 2015: 60.0 m³/sVakkola 2016: 34.0 m³/sVakkola 2017: 75.0 m³/sVakkola 2018: 60.0 m³/sVakkola 2019: 61.3 m³/sVakkola 2020: 90.0 m³/sVakkola 2021: 94.0 m³/sVakkola 2022: 70.0 m³/sVakkola 2023: 75.0 m³/sVakkola 2024: 56.4 m³/sVakkola 2025: 41.0 m³/s

These are the largest daily means, not flood peaks. A peak lasting hours is averaged across a whole day here, so the true instantaneous maximum on the same day was higher — sometimes far higher on a fast-responding catchment. Flood frequency work needs a publisher's own instantaneous series; Hydrionis holds one for 2,236 American gauges and not for this one, so the two are never drawn together. A water year the gauge did not substantially cover produces no value at all rather than a low one.

View the data behind this chart
Underlying data
PeriodVakkola (m³/s)
196378.0
196489.0
1965203
1966106
196777.0
1968109
1969105
197082.0
1971101
197243.0
1973100
197494.0
197582.0
197693.0
197757.0
197869.0
197952.0
1980118
198180.0
198280.0
1983158
198494.0
198581.0
198677.0
198792.0
198873.0
198978.0
199090.0
199164.0
199263.0
1993109
199481.0
199583.0
199648.0
199753.0
1998116
199968.0
200060.0
200155.0
200238.0
200399.0
200463.0
200569.0
200659.0
200770.0
200859.0
200992.4
201092.0
201169.0
201296.0
201345.0
201461.0
201560.0
201634.0
201775.0
201860.0
201961.3
202090.0
202194.0
202270.0
202375.0
202456.4
202541.0

The longest record here

Mean river flow at Vakkola
Annual means of the daily record, 1963–2025. One gauge, not this drainage area.
Mean river flow at VakkolaMean river flow at Vakkola: Vakkola in m³/s, from 1963 to 2025.5101520m³/s19631971197919871995200320112019Vakkola 1963: 8.31 m³/sVakkola 1964: 7.29 m³/sVakkola 1965: 9.01 m³/sVakkola 1966: 14.1 m³/sVakkola 1967: 13.2 m³/sVakkola 1968: 10.1 m³/sVakkola 1969: 9.93 m³/sVakkola 1970: 10.9 m³/sVakkola 1971: 8.64 m³/sVakkola 1972: 11.7 m³/sVakkola 1973: 6.94 m³/sVakkola 1974: 18.8 m³/sVakkola 1975: 7.70 m³/sVakkola 1976: 5.85 m³/sVakkola 1977: 14.9 m³/sVakkola 1978: 9.47 m³/sVakkola 1979: 12.2 m³/sVakkola 1980: 11.8 m³/sVakkola 1981: 19.4 m³/sVakkola 1982: 12.6 m³/sVakkola 1983: 10.4 m³/sVakkola 1984: 17.8 m³/sVakkola 1985: 13.3 m³/sVakkola 1986: 13.0 m³/sVakkola 1987: 13.1 m³/sVakkola 1988: 14.0 m³/sVakkola 1989: 12.3 m³/sVakkola 1990: 13.8 m³/sVakkola 1991: 11.8 m³/sVakkola 1992: 15.0 m³/sVakkola 1993: 7.71 m³/sVakkola 1994: 11.3 m³/sVakkola 1995: 11.7 m³/sVakkola 1996: 9.70 m³/sVakkola 1997: 7.25 m³/sVakkola 1998: 13.5 m³/sVakkola 1999: 10.3 m³/sVakkola 2000: 12.4 m³/sVakkola 2001: 8.31 m³/sVakkola 2002: 8.12 m³/sVakkola 2003: 6.30 m³/sVakkola 2004: 14.5 m³/sVakkola 2005: 10.0 m³/sVakkola 2006: 10.2 m³/sVakkola 2007: 11.9 m³/sVakkola 2008: 15.1 m³/sVakkola 2009: 7.81 m³/sVakkola 2010: 7.87 m³/sVakkola 2011: 9.64 m³/sVakkola 2012: 15.1 m³/sVakkola 2013: 10.2 m³/sVakkola 2014: 7.95 m³/sVakkola 2015: 10.2 m³/sVakkola 2016: 9.66 m³/sVakkola 2017: 13.7 m³/sVakkola 2018: 9.01 m³/sVakkola 2019: 11.7 m³/sVakkola 2020: 12.6 m³/sVakkola 2021: 11.4 m³/sVakkola 2022: 9.78 m³/sVakkola 2023: 12.1 m³/sVakkola 2024: 14.0 m³/sVakkola 2025: 11.7 m³/s

Annual means computed by Hydrionis from the published daily record, drawn only for years with at least 300 days held. They summarise this gauge's own record and say nothing about any other watercourse in this area.

View the data behind this chart
Underlying data
PeriodVakkola (m³/s)
19638.31
19647.29
19659.01
196614.1
196713.2
196810.1
19699.93
197010.9
19718.64
197211.7
19736.94
197418.8
19757.70
19765.85
197714.9
19789.47
197912.2
198011.8
198119.4
198212.6
198310.4
198417.8
198513.3
198613.0
198713.1
198814.0
198912.3
199013.8
199111.8
199215.0
19937.71
199411.3
199511.7
19969.70
19977.25
199813.5
199910.3
200012.4
20018.31
20028.12
20036.30
200414.5
200510.0
200610.2
200711.9
200815.1
20097.81
20107.87
20119.64
201215.1
201310.2
20147.95
201510.2
20169.66
201713.7
20189.01
201911.7
202012.6
202111.4
20229.78
202312.1
202414.0
202511.7

Every gauge Hydrionis holds within this area

Gauges within the Porvoonjoki and what each holds
GaugeMeasuresValuesRecord
Vakkolamean river flow23,2531963–2026
Patomäenkoskimean river flow4,7441993–2026
Kukonkoskimean river flow3,2881980–1988
Strömsbergmean river flow2,8001991–1998

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 — 18. 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
GaugeEvidenceEstablished
VakkolaStated by the publisher on the record this gauge’s observations came from.With the observations
PatomäenkoskiStated by the publisher on the record this gauge’s observations came from.With the observations
KukonkoskiStated by the publisher on the record this gauge’s observations came from.With the observations
StrömsbergStated by the publisher on the record this gauge’s observations came from.With the observations

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
SignalHeldCounts
Gauges holding a real record4yes, 3 or more
Years spanned64yes, 20 or more
Values held34,085yes, 1000 or more
Distinct measurements1no
Publishers measuring it1no
Official identifiers1recorded, not counted

Use this data

Use this data

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

Attribution you are required to give

These are conditions of the licences the underlying data is published under. They are obligations to the publishers, not to Hydrionis, and they apply to you directly whether or not you mention Hydrionis at all.

Contains data from the Finnish Environment Institute (Syke), licensed under CC BY 4.0.

Suggested citation for Hydrionis

Hydrionis (2026), Porvoonjoki gauge records, accessed 2026-10-05, hydrionis.com/waters/finland-porvoonjoki/

Cite Hydrionis where you rely on the compilation, the normalisation, the eligibility judgements or a chart. Where you use an unmodified published value, the publisher’s attribution is the one that is required; crediting Hydrionis as well is welcome and is not something Hydrionis can require of you.

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 Porvoonjoki 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.

Where these figures come from

MeasuredHigh confidence2026-09-30

Source: Syke — Hydrologiarajapinta — Finnish national hydrological archive, 1800500. Licence: Open — attribution required (attribution required).

Method: Daily discharge exactly as the Finnish Environment Institute publishes it. Syke computes the daily value from its own measurement and rating curves; Hydrionis does not recompute it, because a mean derived from whatever sub-daily data happens to be exposed would be a different statistic under the same name. Values Syke flags as possibly erroneous are not stored.

44 of these values (under 1%) are interpolated by Syke rather than measured, and are marked as such in its own archive. Station in the Porvoonjoki main drainage basin, Vakkolan a sub-basin. Discharge is a property of this gauge and this reach, not of the river as a whole.

Retrieved 1 October 2026.