River Colne
5 monitoring stations on this water in England, holding 4,251 values between 1934 and 2026. A named watercourse. The gauges below sit on it, at points its publisher records.
The monitoring network on this water
Hydrionis holds 4,251 values from 5 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.
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.
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.
| 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 |
View the data behind this chart
| Period | River Colne at Watford Berrygrove (m³/s) |
|---|---|
| 1934 | 0.512 |
| 1935 | 0.600 |
| 1936 | 3.20 |
| 1937 | 2.76 |
| 1938 | 2.21 |
| 1939 | 4.38 |
| 1940 | 1.27 |
| 1941 | 1.36 |
| 1942 | 1.30 |
| 1943 | 2.43 |
| 1944 | 0.531 |
| 1945 | 0.780 |
| 1946 | 0.801 |
| 1947 | 2.09 |
| 1948 | 1.02 |
| 1949 | 0.861 |
| 1950 | 0.553 |
| 1951 | 2.01 |
| 1952 | 1.37 |
| 1953 | 1.30 |
| 1954 | 0.263 |
| 1955 | 1.62 |
| 1956 | 1.17 |
| 1957 | 0.897 |
| 1958 | 0.792 |
| 1959 | 2.01 |
| 1960 | 0.675 |
| 1961 | 1.89 |
| 1962 | 1.68 |
| 1963 | 0.321 |
| 1964 | 0.357 |
| 1965 | 0.278 |
| 1966 | 0.647 |
| 1967 | 1.07 |
| 1968 | 1.35 |
| 1969 | 1.78 |
| 1970 | 0.670 |
| 1971 | 1.29 |
| 1972 | 0.675 |
| 1973 | 0.219 |
| 1974 | 0.243 |
| 1975 | 1.65 |
| 1976 | 0.375 |
| 1977 | 1.23 |
| 1978 | 1.41 |
| 1979 | 1.17 |
| 1980 | 1.16 |
| 1981 | 0.616 |
| 1982 | 1.47 |
| 1983 | 1.52 |
| 1984 | 1.25 |
| 1985 | 1.30 |
| 1986 | 1.57 |
| 1987 | 1.00 |
| 1988 | 2.86 |
| 1989 | 0.605 |
| 1990 | 0.898 |
| 1991 | 0.206 |
| 1992 | 0.130 |
| 1993 | 1.73 |
| 1994 | 4.36 |
| 1995 | 2.70 |
| 1996 | 0.906 |
| 1997 | 0.364 |
| 1998 | 0.723 |
| 1999 | 3.35 |
| 2000 | 1.20 |
| 2001 | 4.07 |
| 2002 | 1.68 |
| 2003 | 4.58 |
| 2004 | 1.34 |
| 2005 | 0.702 |
| 2006 | 0.611 |
| 2007 | 1.27 |
| 2008 | 2.05 |
| 2009 | 1.27 |
| 2010 | 1.19 |
| 2011 | 1.02 |
| 2012 | 0.421 |
| 2013 | 1.52 |
| 2014 | 3.72 |
| 2015 | 1.26 |
| 2016 | 1.12 |
| 2017 | 0.396 |
| 2018 | 0.652 |
| 2019 | 0.420 |
| 2020 | 0.992 |
| 2021 | 3.53 |
| 2022 | 1.23 |
| 2023 | 2.71 |
| 2024 | 2.81 |
| 2025 | 2.51 |
| 2026 | 1.52 |
About this series
| Source | Environment Agency — Hydrology Data Explorer API · Open Government Licence v3.0 |
|---|---|
| How the values came to exist | Measured |
| Period held | 1934–2026 |
| Completeness | 100.0% of the periods in that span are held. |
| Continuity | Continuous: every year from 1934 to 2026 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
| Gauge | Measures | Values | Record |
|---|---|---|---|
| River Colne at Watford Berrygrove | mean river flow, mean monthly river flow | 1,184 | 1934–2026 |
| River Colne at Denham Colne | mean river flow, mean monthly river flow | 952 | 1952–2026 |
| River Colne at Lexden | mean river flow, mean monthly river flow | 794 | 1959–2026 |
| River Colne at Poole Street | mean river flow, mean monthly river flow | 732 | 1963–2025 |
| River Colne at Colne Bridge | mean river flow, mean monthly river flow | 589 | 1965–2026 |
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.
| Gauge | Evidence | Established |
|---|---|---|
| River Colne at Watford Berrygrove | Stated by the publisher — Environment Agency hydrology station register, riverName field — https://environment.data.gov.uk/hydrology/id/stations | 2026-10-02 |
| River Colne at Denham Colne | Stated by the publisher — Environment Agency hydrology station register, riverName field — https://environment.data.gov.uk/hydrology/id/stations | 2026-10-02 |
| River Colne at Lexden | Stated by the publisher — Environment Agency hydrology station register, riverName field — https://environment.data.gov.uk/hydrology/id/stations | 2026-10-02 |
| River Colne at Poole Street | Stated by the publisher — Environment Agency hydrology station register, riverName field — https://environment.data.gov.uk/hydrology/id/stations | 2026-10-02 |
| River Colne at Colne Bridge | 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 4 of them, which makes it a full profile.
| Signal | Held | Counts |
|---|---|---|
| Gauges holding a real record | 5 | yes, 3 or more |
| Years spanned | 93 | yes, 20 or more |
| Values held | 4,251 | 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
Use this data
- Machine-readable JSON
/api/v1/observations/by-subject/gauge-ea-0de5636a-5fc2-42de-846d-28ba870aff7b.json - How to cite this, and who you must credit
- How these figures were produced
- Request this at a different scale, format or geography
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 Colne gauge records, accessed 2026-10-05, hydrionis.com/waters/england-river-colne/
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.
Where these figures come from
Source: EA — Hydrology Data Explorer API, EA measure 0de5636a-5fc2-42de-846d-28ba870aff7b-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.