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, students920,914 relevant observations
920,914
Observations available
5
Relevant datasets
1836–2026
Period covered
5
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. The ingestion pipeline is deterministic and the calculation date is fixed, so a rebuild produces 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 Flow Dataset255,7371879–2026Commercial use permitted
England River Water Quality Dataset252,8572000–2025Commercial use permitted
England Groundwater Level Dataset189,7201836–2026Commercial use permitted
UK Historical Rainfall Dataset173,0121836–2026Commercial use permitted
Hydrionis Derived Climatology Dataset49,5881840–2010Commercial 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

Access

Everything referenced here is available through the JSON API and, where the source licence permits redistribution, as CSV extracts. Field definitions are in the data dictionary.

For bulk extracts, higher-volume API access, commercial licensing or bespoke work, see data enquiries.

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