HydrionisGlobal Water Intelligence
Solutions

Hydrionis for research and academia

Assembled long records with full provenance, stable identifiers, versioned datasets and a citation for each — the things that make a dataset usable in work that has to survive peer review.

Hydrologists, environmental scientists, economists, students1,835,565 relevant observations
1,835,565
Observations available
5
Relevant datasets
1827–2026
Period covered
4
Commercially reusable

What you can answer here

Is this reproducible?

Every derived value records its method, method version, formula and the identifier of every input observation. Collection is deterministic and the calculation date is fixed, so the same inputs always produce the same numbers.

Go to the data →

How do I cite it?

Each dataset generates a suggested citation including its version. Cite the version — datasets change as publishers release.

Go to the data →

Relevant datasets

DatasetObservationsCoverageLicence
England River Water Quality Dataset748,1602000–2025Commercial use permitted
Hydrionis Derived Climatology Dataset468,0891827–2026Restricted
England River Flow Dataset255,7391879–2026Commercial use permitted
England Groundwater Level Dataset189,9041836–2026Commercial use permitted
UK Historical Rainfall Dataset173,6731836–2026Commercial use permitted

Key measures

Full dictionary →
MeasureDefinitionUnit
Annual precipitationTotal depth of precipitation falling over a defined area in a calendar or water year.
Annual totals for different countries are not comparable as a measure of water availability. A large arid country and a small wet one can have similar national average rainfall while having entirely different renewable water resources per person. Gauge networks also differ in density, and mountain precipitation is systematically under-measured.
mm
Mean river flowAverage volumetric discharge past a gauging station over a stated period.
Flow is a property of a specific gauge on a specific reach, and cannot be attributed to a river as a whole. Two gauges on the same river can differ by an order of magnitude. Where a station measures flow through a sluice, lock or pumping station — much of the Dutch network does — discharge is signed and a negative value means water moving in the reverse direction, which is a real operating state and not an error. Managed flow of that kind is not comparable with discharge at a natural gauging station, because it reflects operational decisions as well as hydrology.
m³/s
Groundwater levelElevation of the water table or piezometric surface at a monitoring borehole.
Levels are specific to a borehole and its aquifer, and must be read against that borehole’s own historic range. Absolute elevations from different boreholes are not comparable.
m

What Hydrionis does not hold for you

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.

The bulk extract archive is at downloads, and the datasets above each carry their own file where the licence permits one.

Field definitions are in the data dictionary. What Hydrionis withholds and why is on why some values are missing. What exists today for organisations, and what does not, is on Hydrionis Professional.

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