The monitoring network on this water

Hydrionis holds 1,133 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.

2
Gauges
1,133
Values held
1966–2026
Record spans
114 km²
Catchment above the deepest gauge

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 La Mare à Saint-Marcellin-en-Forez
Each month's mean discharge as the publisher computed it, which shows the seasonal shape an annual mean flattens away. 1971–2026.
Shading marks when something was recorded, not what caused the line.
Monthly mean flow at La Mare à Saint-Marcellin-en-ForezMonthly mean flow at La Mare à Saint-Marcellin-en-Forez: La Mare à Saint-Marcellin-en-Forez in m³/s, from 1971 to 2026.European drought024m³/s19711978198519921999200620132020

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 (1 event)

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.

EventTypePeriodStandingAuthority
European droughtDrought declaration2022-05-01 – 2022-10-31Documented record
Compiled record

Not shown on this chart

  • The 1976 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • The 2022 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • Yorkshire drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • 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
PeriodLa Mare à Saint-Marcellin-en-Forez (m³/s)
19711.40
19720.941
19731.12
19740.628
19751.18
19760.681
19771.17
19780.955
19790.879
19801.67
19813.21
19823.00
19831.17
19840.694
19851.20
19860.433
19871.29
19881.45
19890.553
19900.229
19911.08
19920.633
19930.376
19943.82
19951.44
19961.96
19972.08
19980.591
19990.505
20001.45
20011.42
20020.523
20031.56
20041.81
20051.10
20060.481
20070.462
20080.849
20091.57
20100.728
20111.05
20121.09
20130.893
20142.11
20151.15
20160.594
20170.600
20182.10
20190.352
20200.844
20210.719
20220.959
20230.331
20240.801
20251.36
20260.869

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
Office français de la biodiversité / SCHAPI — Hydrométrie — French river flow and stage · Licence Ouverte / Open Licence v2.0 (Etalab)
How the values came to existMeasured
Period held1971–2026
Completeness100.0% of the periods in that span are held.
ContinuityContinuous: every year from 1971 to 2026 is held.
Last read from the publisher2026-10-01
RedistributionPermitted by the upstream licences
Commercial reusePermitted by the upstream licences. No Hydrionis access tier can widen this.
MethodologyHow this was produced

Every gauge Hydrionis holds here

Gauges on the la Mare and what each holds
GaugeMeasuresValuesRecord
La Mare à Saint-Marcellin-en-Forezmean monthly river flow6251971–2026
La Mare à Villemagne-l'Argentièremean monthly river flow5081966–2026

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
GaugeEvidenceEstablished
La Mare à Saint-Marcellin-en-ForezStated by the publisher — Hub'Eau hydrometry site reference, libelle_cours_eau, code_cours_eau and surface_bv fields — https://hubeau.eaufrance.fr/api/v2/hydrometrie/referentiel/sites2026-10-02
La Mare à Villemagne-l'ArgentièreStated by the publisher — Hub'Eau hydrometry site reference, libelle_cours_eau, code_cours_eau and surface_bv fields — https://hubeau.eaufrance.fr/api/v2/hydrometrie/referentiel/sites2026-10-02

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 2 of them, which makes it a profile, not indexed.

Information-gain signals held for this water body
SignalHeldCounts
Gauges holding a real record2no
Years spanned61yes, 20 or more
Values held1,133yes, 1000 or more
Distinct measurements1no
Publishers measuring it1no
Official identifiers2recorded, not counted

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.

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.

Source: Hub’Eau / Système d’information sur l’eau, under Licence Ouverte (Etalab).

Suggested citation for Hydrionis

Hydrionis (2026), la Mare gauge records, accessed 2026-10-05, hydrionis.com/waters/france-la-mare/

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 la Mare 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

MeasuredHigh confidenceSeptember 2026

Source: Hub'Eau — Hydrométrie — French river flow and stage, K0643110. Licence: Open — attribution required (attribution required).

Method: Monthly mean discharge (QmM) computed by the publisher from its validated sub-hourly record, reported in litres per second and converted to cubic metres per second as they are collected. Where a site has been measured by more than one station, the station with the longest published series is used rather than blending stations whose values for the same month can differ.

Measured on la Mare.

Retrieved 1 October 2026.