River Mimram — monitoring and records

The monitoring network on this water

Hydrionis holds 1,863 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

1,863

Values held

1952–2026

Record spans

Gauges on the River Mimram

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 Mimram at Panshanger

Each month's mean discharge as the publisher computed it, which shows the seasonal shape an annual mean flattens away. 1952–2026.

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 Mimram at Panshanger (m³/s)
1952	0.704
1953	0.779
1954	0.433
1955	0.728
1956	0.576
1957	0.582
1958	0.516
1959	0.874
1960	0.456
1961	1.10
1962	0.683
1963	0.364
1964	0.431
1965	0.332
1966	0.556
1967	0.754
1968	0.745
1969	0.919
1970	0.454
1971	0.580
1972	0.447
1973	0.318
1974	0.244
1975	0.700
1976	0.380
1977	0.518
1978	0.531
1979	0.504
1980	0.718
1981	0.454
1982	0.629
1983	0.706
1984	0.559
1985	0.675
1986	0.453
1987	0.504
1988	0.898
1989	0.446
1990	0.522
1991	0.345
1992	0.222
1993	0.765
1994	1.34
1995	0.732
1996	0.491
1997	0.252
1998	0.298
1999	0.716
2000	0.387
2001	1.22
2002	0.740
2003	1.16
2004	0.552
2005	0.392
2006	0.241
2007	0.458
2008	0.633
2009	0.546
2010	0.559
2011	0.500
2012	0.255
2013	0.868
2014	0.944
2015	0.648
2016	0.639
2017	0.363
2018	0.388
2019	0.363
2020	0.572
2021	1.02
2022	0.569
2023	0.740
2024	0.950
2025	1.17
2026	0.688

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	1952–2026
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1952 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

Gauges on the River Mimram and what each holds
Gauge	Measures	Values	Record
River Mimram at Panshanger	mean river flow, mean monthly river flow	956	1952–2026
River Mimram at Fulling Mill	mean river flow, mean monthly river flow	907	1955–2026

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 Mimram at Panshanger	Stated by the publisher — Environment Agency hydrology station register, riverName field — https://environment.data.gov.uk/hydrology/id/stations	2026-10-02
River Mimram at Fulling Mill	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	75	yes, 20 or more
Values held	1,863	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-e61b060b-5b5b-4695-a2be-79e50c699c2d.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 Mimram gauge records, accessed 2026-10-05, hydrionis.com/waters/england-river-mimram/

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 Mimram 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 confidence2025

Source: EA — Hydrology Data Explorer API, EA measure e61b060b-5b5b-4695-a2be-79e50c699c2d-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.