River Granta — monitoring and records

The monitoring network on this water

Hydrionis holds 1,608 values from 2 gauges on this water. Discharge is a property of a gauge and its reach, not of this water as a whole, so this page reports the network and its records rather than a single figure.

Gauges

1,608

Values held

1949–2026

Record spans

Gauges on the River Granta

2 monitoring points, positioned as the publisher records them.

The seasonal shape

An annual mean says how much water a river carried. A monthly record says when — and on most rivers the difference between a wet winter and a dry summer is larger than the difference between one year and the next.

Monthly mean flow at River Granta at Stapleford

Each month's mean discharge as the publisher computed it, which shows the seasonal shape an annual mean flattens away. 1949–2025.

Show relevant events (4 events)Shading marks when something was recorded, not what caused the line.

Taken as the publisher computes it rather than recomputed by Hydrionis from daily values: the publisher knows which of its readings passed validation. Months the gauge did not cover are absent rather than interpolated, and the line breaks where they fall.

What the shaded periods are (4 events)

A shaded period marks when something was recorded, not what caused the shape of the line. Where the two coincide, they coincided.

Documented record — A documented event, compiled from cited sources after it happened. The dates are as good as the record, which for older events can mean the month rather than the day.

Event	Type	Period	Standing	Authority
The 1976 drought	Drought declaration	1975-05-01 – 1976-08-31	Documented record	Compiled record
Yorkshire drought	Drought declaration	1995-04-01 – 1996-03-31	Documented record	Compiled record
The 2022 drought	Drought declaration	2022-03-01 – 2022-10-31	Documented record	Compiled record
European drought	Drought declaration	2022-05-01 – 2022-10-31	Documented record	Compiled record

Not shown on this chart

Cantareira water crisis, São Paulo — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cape Town Day Zero — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Hurricane Katrina water and sanitation collapse — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.

View the data behind this chart

Underlying data
Period	River Granta at Stapleford (m³/s)
1949	0.105
1950	0.065
1951	0.379
1952	0.410
1953	0.249
1954	0.106
1955	0.547
1956	0.450
1957	0.119
1958	0.277
1959	1.23
1960	0.351
1961	0.732
1962	0.636
1963	0.054
1964	0.101
1965	0.0048
1966	0.179
1967	0.214
1968	0.440
1969	0.620
1970	0.602
1971	0.471
1972	0.512
1973	0.023
1974	0.016
1975	0.489
1976	0.091
1977	0.504
1978	0.443
1979	0.287
1980	0.405
1981	0.205
1982	0.521
1983	0.411
1984	0.470
1985	0.494
1986	0.365
1987	0.316
1988	0.897
1989	0.225
1990	0.192
1991	0.0061
1992	0.015
1993	0.404
1994	0.644
1995	0.642
1996	0.168
1997	0.015
1998	0.089
1999	0.309
2000	0.241
2001	0.910
2002	0.454
2003	0.840
2004	0.513
2005	0.136
2006	0.070
2007	0.475
2008	0.360
2009	0.331
2010	0.471
2011	0.412
2012	0.034
2013	0.739
2014	0.906
2015	0.586
2016	0.479
2017	0.122
2018	0.446
2019	0.046
2020	0.246
2021	0.680
2022	0.317
2023	0.358
2024	0.552
2025	0.098

About this series

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	Environment Agency — Hydrology Data Explorer API · Open Government Licence v3.0
How the values came to exist	Measured
Period held	1949–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1949 to 2025 is held.
Last read from the publisher	2026-10-01
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

Every gauge Hydrionis holds here

Gauges on the River Granta and what each holds
Gauge	Measures	Values	Record
River Granta at Stapleford	mean river flow, mean monthly river flow	916	1949–2025
River Granta at Babraham	mean river flow, mean monthly river flow	692	1963–2026

How these gauges were attached to this water

Named by the publisher Each gauge here names this water in the publisher’s own station record. Hydrionis has not inferred the connection from station names.

What each gauge’s link to this water rests on
Gauge	Evidence	Established
River Granta at Stapleford	Stated by the publisher — Environment Agency hydrology station register, riverName field — https://environment.data.gov.uk/hydrology/id/stations	2026-10-02
River Granta at Babraham	Stated by the publisher — Environment Agency hydrology station register, riverName field — https://environment.data.gov.uk/hydrology/id/stations	2026-10-02

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	2	no
Years spanned	78	yes, 20 or more
Values held	1,608	yes, 1000 or more
Distinct measurements	2	yes, 2 or more
Publishers measuring it	1	no
Official identifiers	0	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/gauge-ea-1c1e42b5-f8e3-4811-b5cc-37330e028d61.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.

Contains public sector information licensed under the Open Government Licence v3.0.

Environment Agency — Open Government Licence v3.0 (licence text)

Suggested citation for Hydrionis

Hydrionis (2026), River Granta gauge records, accessed 2026-10-05, hydrionis.com/waters/england-river-granta/

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 River Granta 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

Spatially aggregatedHigh confidence2022

Source: EA — Hydrology Data Explorer API, EA measure 1c1e42b5-f8e3-4811-b5cc-37330e028d61-flow-m-86400-m3s-qualified. Licence: Open — attribution required (attribution required).

Method: Mean of the twelve monthly means for the year. Computed from months rather than from daily readings directly, so that a year with uneven observation is not weighted toward its best-observed months. Years with any month missing are not published.

Aggregated by Hydrionis from daily mean flow published by the Environment Agency under the Open Government Licence v3.0.

Retrieved 1 October 2026.