The monitoring network within this area

Hydrionis holds 40,866 values from 5 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.

5

Gauges

40,866

Values held

1921–2026

Record spans

985 km²

Area

Gauges within the Ronnebyån drainage basin

5 monitoring points, positioned as the publisher records them.

How low, how high and how variable this gauge runs

A hydrograph says what happened; these say how often. Read off BOASJÖBÄCK's whole daily record between 1982 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.

0.014 m³/s

Q95 low flow

0.221 m³/s

Q50 median flow

0.907 m³/s

Q10 high flow

Largest day of each water year at BOASJÖBÄCK

The highest daily mean discharge in each October-to-September water year, 1982–2025.

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
Period	BOASJÖBÄCK (m³/s)
1982	1.45
1983	0.980
1984	1.66
1985	2.41
1986	1.24
1987	2.63
1988	0.890
1989	1.28
1990	1.62
1991	0.860
1992	1.21
1993	1.81
1994	3.80
1995	1.76
1996	1.60
1997	0.820
1998	1.90
1999	2.45
2000	1.82
2001	2.92
2002	0.890
2003	0.950
2004	1.23
2005	2.80
2006	1.87
2007	1.42
2008	1.01
2009	1.53
2010	2.73
2011	1.55
2012	1.50
2013	1.05
2014	1.59
2015	1.11
2016	0.630
2017	1.66
2018	1.51
2019	2.20
2020	0.640
2021	1.23
2022	2.76
2023	1.67
2024	1.16
2025	0.560

The longest record here

Mean river flow at BOASJÖBÄCK

Annual means of the daily record, 1983–2025. One gauge, not this drainage area.

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
Period	BOASJÖBÄCK (m³/s)
1983	0.343
1984	0.352
1985	0.480
1986	0.402
1987	0.353
1988	0.633
1989	0.213
1990	0.286
1991	0.340
1992	0.319
1993	0.344
1994	0.645
1995	0.523
1996	0.357
1997	0.306
1998	0.380
1999	0.451
2000	0.484
2001	0.459
2002	0.518
2003	0.187
2004	0.343
2005	0.252
2006	0.504
2007	0.627
2008	0.427
2009	0.230
2010	0.465
2011	0.468
2012	0.330
2013	0.234
2014	0.424
2015	0.403
2016	0.238
2017	0.317
2018	0.322
2019	0.315
2020	0.354
2021	0.383
2022	0.256
2023	0.430
2024	0.391
2025	0.197

Every gauge Hydrionis holds within this area

Gauges within the Ronnebyån and what each holds
Gauge	Measures	Values	Record
BOASJÖBÄCK	mean river flow	16,146	1982–2026
KROKFJORDEN	mean river flow	10,256	1998–2026
HEABY	mean river flow	6,394	1995–2012
LÅNGGÖL	mean river flow	4,963	1921–1935
KLÅVBEN	mean river flow	3,107	1938–1947

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 — 82000. 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
BOASJÖBÄCK	Stated by the publisher on the record this gauge’s observations came from.	With the observations
KROKFJORDEN	Stated by the publisher on the record this gauge’s observations came from.	With the observations
HEABY	Stated by the publisher on the record this gauge’s observations came from.	With the observations
LÅNGGÖL	Stated by the publisher on the record this gauge’s observations came from.	With the observations
KLÅVBEN	Stated 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
Signal	Held	Counts
Gauges holding a real record	5	yes, 3 or more
Years spanned	106	yes, 20 or more
Values held	40,866	yes, 1000 or more
Distinct measurements	1	no
Publishers measuring it	1	no
Official identifiers	2	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/se-smhi-2318.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

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.

Data from Sveriges meteorologiska och hydrologiska institut, used under CC BY 4.0.

Sveriges meteorologiska och hydrologiska institut — CC BY 4.0 (licence text)

Suggested citation for Hydrionis

Hydrionis (2026), Ronnebyån gauge records, accessed 2026-10-05, hydrionis.com/waters/sweden-ronnebyan/

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 Ronnebyån 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

MeasuredMedium confidence2026-09-30

Source: SMHI — Swedish hydrological observations, 2318. Licence: Open — attribution required (attribution required).

Method: Daily discharge exactly as SMHI publishes it, from its corrected archive. SMHI computes the daily value from its own sub-daily 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.

Checked and approved by SMHI except 2026-02-01 to 2026-09-30 (not yet checked). Station in the RONNEBYÅN main drainage basin, 57 km². Discharge is a property of this gauge and this reach, not of the river as a whole.

Retrieved 1 October 2026.