Poland Hydrological Observations Dataset

What this looks like

One real series from the dataset, and real rows from the head of its published extract. Neither is a mock-up: the rows below are the same rows, unchanged, that are in the file you would download.

Sample rows

12 of 3,041 rows Taken from the start of observations-river-flow-pl-imgw-hydro.csv. These are sample rows, not the dataset.

Sample rows from the Poland Hydrological Observations Dataset extract
`metric_id`	`subject_id`	`subject_kind`	`value`	`censored`	`censor_operator`	`censor_threshold`	`censor_limit`	`censor_reported`	`unit`	`period_start`	`period_end`	`period_kind`	`basis`	`confidence`	`source_id`	`source_ref`	`qualifier`	`superseded`	`retrieved`
river-flow-mean	pl-imgw-149180010	geography	10.3	—	—	—	—	—	m³/s	2026-08-26	2026-08-26	day	measured	medium	pl-imgw-hydro	149180010	—	—	2026-10-01
river-flow-mean	pl-imgw-149180010	geography	12.5	—	—	—	—	—	m³/s	2026-10-01	2026-10-01	day	measured	medium	pl-imgw-hydro	149180010	—	—	2026-10-01
river-flow-mean	pl-imgw-149180020	geography	8.32	—	—	—	—	—	m³/s	2026-08-26	2026-08-26	day	measured	medium	pl-imgw-hydro	149180020	—	—	2026-10-01
river-flow-mean	pl-imgw-149180020	geography	8.32	—	—	—	—	—	m³/s	2026-10-01	2026-10-01	day	measured	medium	pl-imgw-hydro	149180020	—	—	2026-10-01
river-flow-mean	pl-imgw-149180030	geography	3.3	—	—	—	—	—	m³/s	2026-08-26	2026-08-26	day	measured	medium	pl-imgw-hydro	149180030	—	—	2026-10-01
river-flow-mean	pl-imgw-149180030	geography	4.14	—	—	—	—	—	m³/s	2026-10-01	2026-10-01	day	measured	medium	pl-imgw-hydro	149180030	—	—	2026-10-01
river-flow-mean	pl-imgw-149180040	geography	0.46	—	—	—	—	—	m³/s	2026-08-26	2026-08-26	day	measured	medium	pl-imgw-hydro	149180040	—	—	2026-10-01
river-flow-mean	pl-imgw-149180040	geography	0.55	—	—	—	—	—	m³/s	2026-10-01	2026-10-01	day	measured	medium	pl-imgw-hydro	149180040	—	—	2026-10-01
river-flow-mean	pl-imgw-149180050	geography	0.16	—	—	—	—	—	m³/s	2026-08-26	2026-08-26	day	measured	medium	pl-imgw-hydro	149180050	—	—	2026-10-01
river-flow-mean	pl-imgw-149180050	geography	0.29	—	—	—	—	—	m³/s	2026-10-01	2026-10-01	day	measured	medium	pl-imgw-hydro	149180050	—	—	2026-10-01
river-flow-mean	pl-imgw-149180060	geography	1.01	—	—	—	—	—	m³/s	2026-08-26	2026-08-26	day	measured	medium	pl-imgw-hydro	149180060	—	—	2026-10-01
river-flow-mean	pl-imgw-149180060	geography	1.08	—	—	—	—	—	m³/s	2026-10-01	2026-10-01	day	measured	medium	pl-imgw-hydro	149180060	—	—	2026-10-01

Download these rows as CSV — the same twelve, with the column header, for testing a loader before committing to the full file.

Methodology

Collected from the IMGW public data API under the Polish Open Data Act of 2021 and Commission Implementing Regulation (EU) 2023/138 on high-value datasets, which requires hydrological data to be free, machine-readable and reusable commercially. The interface serves the latest reading per station and nothing older, so this runs in accumulate mode and Hydrionis becomes the archive of a snapshot the API does not keep. Each quantity carries its own measurement timestamp and is filed under the day it was taken rather than the day it was fetched — level, discharge and temperature are read at different times and frequently on different days. Water level is published in centimetres above each station’s own gauge datum and converted to metres; the datum stays local. Readings older than a fortnight are refused, because a rolling snapshot repeats a stale value indefinitely.

What this dataset cannot tell you

Read before relying on these figures

A rolling snapshot, not an archive. The record begins when Hydrionis began accumulating it, and says nothing about how long Poland has been gauging its rivers — which is far longer. IMGW holds the real archive and releases it on request.
These are single readings, not daily means. One measurement taken at one moment, filed under the day it was taken; calling it a mean would be a different statistic under the same name.
Water level is measured against each station’s own gauge datum. Two Polish stations reading the same level are not at the same height, and a level is not the depth of the water.
Discharge is reported for fewer stations than level, and is a property of the gauge and its reach rather than of the river.
The publisher also serves ice phenomena and the state’s own warning and alarm thresholds. Those are recorded on the station rather than as observations, because a threshold is a regulatory decision and not a measurement.

Coverage

Subjects	Polish national hydrological gauging stations — 904 held
Period	2026–2026
Units	m, m³/s, °C
Update cadence	Daily
Identifier	`poland-hydrology` v1.0.0

Fields

Data dictionary →

Every metric this dataset carries, with the unit it is stored in and the geography level it is reported at. Full definitions are in the data dictionary.

Identifier	Field	Unit	Reported at
`river-level`	River level Height of the water surface at a gauging station, measured against that station’s own zero point.	m	river-gauge
`river-flow-mean`	Mean river flow Average volumetric discharge past a gauging station over a stated period.	m³/s	river-gauge
`water-temperature`	Water temperature Temperature of the water body or supply at the point of measurement.	°C	monitoring-station, river-gauge, supply-zone

Rights and access

Licence position

Open with attribution. Derivative use true; redistribution true; commercial reuse true.

Permitted uses

Public display
Derived analysis
API delivery
Bulk download
Commercial use

Available to: Public, Developer, Research, Professional, Enterprise. These follow from the rights of the contributing publishers, not from a Hydrionis pricing decision — no access tier can widen what a publisher withheld.

Contributing sources

Instytut Meteorologii i Gospodarki Wodnej — Państwowy Instytut Badawczy — Dane publiczne — hydrological observations (Polish Open Data Act 2021 with EU High-Value Datasets Regulation 2023/138)

Attribution and citation

Cite and reuse →

Two different obligations, deliberately kept apart. One is a condition of somebody else's licence; the other is a request Hydrionis has no standing to enforce.

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 Institute of Meteorology and Water Management — National Research Institute (IMGW-PIB).

Instytut Meteorologii i Gospodarki Wodnej — Państwowy Instytut Badawczy — Polish Open Data Act 2021 with EU High-Value Datasets Regulation 2023/138 (licence text)

Suggested citation for Hydrionis

Hydrionis (2026), Poland Hydrological Observations Dataset, version 1.0.0, accessed 2026-10-05, hydrionis.com/data/datasets/poland-hydrology/

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: Poland Hydrological Observations Dataset 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.

Changelog

Version 1.0.0 — 2026-08-27

First release. Poland joins the platform with full water-body linkage.

Additions

Water level, discharge and water temperature for around 900 stations.
The watercourse each station gauges, carried onto every station as it is collected.

Use this data

Download river-flow observations from IMGW-PIB (3,041 rows) (CSV)
Download chemistry observations from IMGW-PIB (208 rows) (CSV)
Machine-readable JSON /api/v1/datasets/poland-hydrology.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

Every bulk extract ships with a companion metadata file carrying this dataset’s version, its sources, their licences, the attribution you are required to give and the suggested citation — so the terms travel with the file rather than staying on this page.

About this data

The fields a professional user needs to judge whether this is fit for a particular purpose. Deliberately not a score.

About this data

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	Instytut Meteorologii i Gospodarki Wodnej — Państwowy Instytut Badawczy — Dane publiczne — hydrological observations · Polish Open Data Act 2021 with EU High-Value Datasets Regulation 2023/138
How the values came to exist	Mixed across the series — the basis is recorded on every individual value.
Period held	2026–2026
Known gaps	A rolling snapshot, not an archive. The record begins when Hydrionis began accumulating it, and says nothing about how long Poland has been gauging its rivers — which is far longer. IMGW holds the real archive and releases it on request. These are single readings, not daily means. One measurement taken at one moment, filed under the day it was taken; calling it a mean would be a different statistic under the same name. Water level is measured against each station’s own gauge datum. Two Polish stations reading the same level are not at the same height, and a level is not the depth of the water.
Continuity	Version 1.0.0, released 2026-08-27. 1 recorded version; breaking changes and corrections are listed in the changelog above.
Last read from the publisher	2026-10-01 · publisher updates daily
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