SIGNAL · Low water · 2026-08-01

Meuse low flow at Chooz, the 1998 Franco-Belgian flow thresholds and the two Chooz nuclear units, July–November 2026

Accepted

The Hub'Eau record at Chooz (station B720000001, upstream of the plant) shows the Meuse 12-day mean flow below 22 m3/s from 14 July to 24 October 2026 (103 days) and below 20 m3/s from 6 August to 24 October (80 days), with a daily minimum of 15.2 m3/s on 1 October; the 1998 Franco-Belgian agreement sets 22 and 20 m3/s, on a twelve-consecutive-day mean downstream of the plant, as the flows at which safeguard measures start and below which no aggravation is allowed. EDF stopped Chooz unit 2 on 11 July and unit 1 on 1 August. Grand Est nuclear output averaged 3,589 MW from 2 August to 25 October 2026 against 7,296 MW over the same dates in 2025, and 4,765 MW from 26 October to 11 November. Belgium's physical imports from France fell from a mean of 2,210 MW (1 June to 10 July) to 1,350 MW (2 August to 25 October), while the Belgium minus France day-ahead price gap narrowed from 40.3 to 9.2 EUR/MWh.

Geography: Chooz, Ardennes (Meuse gauge B720000001 and nuclear plant) / Grand Est region (Chooz, Cattenom and Nogent nuclear plants) / Metropolitan France (RTE system) / Belgium (Meuse downstream of Chooz; Elia control area). The report that started this signal → Edition: Both Chooz reactors stopped during 103 days of low Meuse flow: the limit was a Franco-Belgian agreement, not cooling. Dossier: reviewed on 2026-11-12.

Series

Organisations

Universe drawn from: EDF — Universal Registration Document 2022, section 1.4.1 (generation allocation contracts) (Holders of capacity shares in named nuclear units; Chooz B1-B2 lists Electrabel. Luminus's 100 MW drawing rights read in its own 2023 sustainability report.); Autorité de sûreté nucléaire — décision n° 2009-DC-0164 du 17 novembre 2009 (Chooz, water withdrawal and discharges) (Annex 1, article 4-II: limits on the water evaporated by the two Chooz B units according to the 12-day mean flow of the Meuse downstream of the site. Read in full on 2026-11-12; the later amending decisions (2017-DC-0616, 2023-DC-0768) were not read by the mapper.); ODRÉ / RTE — Registre national des installations de production et de stockage d'électricité (Queried through the API for non-renewable thermal units above 300 MW (15 units); gas combined cycles at Saint-Avold, Toul, Pont-sur-Sambre, Bayet, Landivisiau, Bouchain, Fos, Martigues and Montoir. The registry gives no operator name; operators were taken from their own pages. EDF's and ENGIE's gas units are covered by their existing entries.); FEBEG — leden (members of the Belgian federation of electricity and gas companies) (Member list read in full for Belgian generators: Engie Electrabel, Luminus, RWE Generation, T-Power, TotalEnergies Centrale Electrique Marchienne-au-Pont retained; pure suppliers left out.); RIWA-Maas — Over RIWA (Association of the Dutch and Belgian water companies drawing on the Meuse; the page does not list members by name, which were taken from press reports and Rijkswaterstaat's 2025 report on state waters as drinking-water sources (intakes at Heel, Brakel and Bergsche Maas).); RTE — Premières analyses sur le fonctionnement du système électrique au cours de l'été 2026 (21 September 2026) (Climate-related nuclear unavailability, gas-fired output, price convergence with Belgium and Germany.); Assemblée nationale — question écrite n° 17856 (JO 1 September 2026) (Chooz stoppage and the 1998 agreement; no answer published when read. Used for the chain, names no organisation other than EDF.); Service public de Wallonie — drought cell press releases (30 July, 6 and 13 August 2026) (Navigation restrictions and drinking-water production in Wallonia.); Commission Internationale de la Meuse — avis d'étiage, week 45 of 2026 (Weekly low-flow monitoring of the basin; also Rijkswaterstaat news, the Flemish drought report (waterinfo.be, October 2026), two Dutch letters to parliament of July 2026 and the Waterschap Limburg decision of July 2026.); Press read on 2026-11-12 (AFP via Connaissance des Énergies (3 August 2026), La Libre, L'Avenir, VRT, NL Times, Selectra, each cited where it supports an entry. EDF's own Chooz notices return 403 to our tools and were not opened by the mapper; the dossier's counter-analyst read them and reports unit 1 reconnected on 26 October 2026 at 12:15 and unit 2 on 9 November 2026 at 14:55, so both units are back on the grid at the date of reading. UNIDEN's and Febeliec's member lists could not be opened.). Each organisation below carries its own verbatim evidence.

Hypotheses

OPEN · confidence low · horizon 2026-12-08. The lowest 12-day mean of the Meuse at Chooz between 12 November and 7 December 2026 is below 20 m3/s. The safety authority's rule then sets the evaporated flow at nil on the thirteenth day, both units stopped in the operator's wording. Pace required, recomputed from the daily flows to 11 November: a first reading under 20 needs the days from 12 November to average under 18.26 m3/s by 21 November, under 19.22 by 22 November, or under 20 over the twelve days to 23 November; earlier dates need lower flows still (under 16.90 by 20 November). All are below the mean flow of 2 to 7 November (20.55; lowest day 19.475 on 7 November). No precedent on these dates in 2015 to 2025. Reading rule for the flow: Hub'Eau, lowest value of the 12-day mean of the daily mean flows (QmnJ) on any day from 12 November to 7 December 2026, read on 8 December 2026 with the values as then published (raw or pre-validated). The Hub'Eau query carries no end date and returns the values published to the day it is opened. If a daily value is missing on that day, the reading is made on the values published and is void if no 12-day mean of the window can be formed. The DREAL gauge B720000001 decides the branch; the operator's gauge B720000004 is read beside it and a difference of branch between the two is reported as such. Neither gauge subtracts the evaporated flow: the downstream value of the rule is lower by up to 2.1 m3/s with two units running, so a reading from 22 to 24.1 leaves it undetermined. The four branches of this reading are read in the order written (lowest mean under 20; from 20 to under 22; at or above 22 with a published flow-linked measure; at or above 22 with none) and the first whose condition holds is the branch. A 12-day mean under 22 m3/s or a measure dated 8 to 31 December 2026 belongs to no branch: those days are read in a follow-up, and the branch read on 8 December stands. Read beside the branch and not defining it: Grand Est nuclear output, mean of the daily means over the 12 days after the first reading under 20, read on 24 December 2026, against 1,098.8 to 4,998.8 MW. Indicators: Lowest 12-day mean of the Meuse daily flows at Chooz, DREAL gauge B720000001, 12 November to 7 December 2026, as published on 8 December 2026; Read beside, not defining the branch: the same lowest 12-day mean on the operator's gauge B720000004; a difference of branch between the two gauges is reported as such; Read beside, not defining the branch: Grand Est nuclear output, mean of the daily means over the 12 days after the first reading under 20, read on 24 December 2026, against 1,098.8 to 4,998.8 MW.

OPEN · confidence low · horizon 2026-12-08. The lowest 12-day mean of the Meuse at Chooz between 12 November and 7 December 2026 is below 22 m3/s and at or above 20 m3/s. The safety authority's rule then limits the evaporated flow to 5 percent of the river flow, about one unit's worth: one unit stopped in the operator's wording, or power reductions that may bear on both units. Pace required, recomputed from the daily flows to 11 November: a first reading under 22 needs the days from 12 November to average under 19.56 m3/s by 20 November or under 20.66 by 21 November; earlier dates need lower flows still (under 19.05 by 19 November). The second figure is the level of 2 to 7 November (mean 20.55); the first lies below it (one day since 31 October, 19.475 on 7 November). Local precedent for a stay between the two figures: 14 July to 5 August 2026 and the 2019 episode. Reading rule for the flow: Hub'Eau, lowest value of the 12-day mean of the daily mean flows (QmnJ) on any day from 12 November to 7 December 2026, read on 8 December 2026 with the values as then published (raw or pre-validated). The Hub'Eau query carries no end date and returns the values published to the day it is opened. If a daily value is missing on that day, the reading is made on the values published and is void if no 12-day mean of the window can be formed. The DREAL gauge B720000001 decides the branch; the operator's gauge B720000004 is read beside it and a difference of branch between the two is reported as such. Neither gauge subtracts the evaporated flow: the downstream value of the rule is lower by up to 2.1 m3/s with two units running, so a reading from 22 to 24.1 leaves it undetermined. The four branches of this reading are read in the order written (lowest mean under 20; from 20 to under 22; at or above 22 with a published flow-linked measure; at or above 22 with none) and the first whose condition holds is the branch. A 12-day mean under 22 m3/s or a measure dated 8 to 31 December 2026 belongs to no branch: those days are read in a follow-up, and the branch read on 8 December stands. Read beside the branch and not defining it: Grand Est nuclear output, mean of the daily means over the 12 days after the first reading under 22, read on 24 December 2026, against 2,548.8 to 6,448.8 MW. Indicators: Lowest 12-day mean of the Meuse daily flows at Chooz, DREAL gauge B720000001, 12 November to 7 December 2026, as published on 8 December 2026, upper bound; Lowest 12-day mean of the Meuse daily flows at Chooz, DREAL gauge B720000001, 12 November to 7 December 2026, as published on 8 December 2026, lower bound; Read beside, not defining the branch: the same lowest 12-day mean on the operator's gauge B720000004; a difference of branch between the two gauges is reported as such; Read beside, not defining the branch: Grand Est nuclear output, mean of the daily means over the 12 days after the first reading under 22, read on 24 December 2026, against 2,548.8 to 6,448.8 MW.

OPEN · confidence low · horizon 2026-12-08. The lowest 12-day mean of the Meuse at Chooz between 12 November and 7 December 2026 is at or above 22 m3/s, and at least one published document attributes a stop or a power reduction of a Chooz unit between the same dates to the Meuse flow. The published document, not the flow series, separates this branch from the next. Precedents: 11 July 2026 (22.995 on the DREAL gauge, 22.923 on the operator's) and autumn 2018 (22.161); counter-case: 10 November 2026 (22.898 on the operator's gauge, no stop reported). Reading rule for the flow: Hub'Eau, lowest value of the 12-day mean of the daily mean flows (QmnJ) on any day from 12 November to 7 December 2026, read on 8 December 2026 with the values as then published (raw or pre-validated). The Hub'Eau query carries no end date and returns the values published to the day it is opened. If a daily value is missing on that day, the reading is made on the values published and is void if no 12-day mean of the window can be formed. The DREAL gauge B720000001 decides the branch; the operator's gauge B720000004 is read beside it and a difference of branch between the two is reported as such. Neither gauge subtracts the evaporated flow: the downstream value of the rule is lower by up to 2.1 m3/s with two units running, so a reading from 22 to 24.1 leaves it undetermined. The four branches of this reading are read in the order written (lowest mean under 20; from 20 to under 22; at or above 22 with a published flow-linked measure; at or above 22 with none) and the first whose condition holds is the branch. A 12-day mean under 22 m3/s or a measure dated 8 to 31 December 2026 belongs to no branch: those days are read in a follow-up, and the branch read on 8 December stands. Reading rule for the measure, as it stands on 8 December 2026: at least one published document dated 12 November to 7 December 2026 that reports a stop or a power reduction of a Chooz unit, whatever its size or duration, and names the Meuse flow, the 1998 agreement or the limit on evaporated water as its reason. One document at any of three kinds of source counts: a notice on the operator's Chooz news page (https://www.edf.fr/la-centrale-nucleaire-de-chooz/les-actualites-de-la-centrale-nucleaire-de-chooz), opened in an ordinary browser (the page refuses automated readers), its title, date and sentence copied into the reading; a news-agency dispatch as republished by the regional and national press (no single public feed: the reading names the titles searched); or a generation unavailability message for Chooz 1 or Chooz 2 that states the cause, on the grid operator's public page of unavailability messages (https://iip.cloud-rte-france.com/production-unavailability; opened once on 12 November 2026: it answers an automated reader, but its messages load by script and are read in a browser). A trade-press article alone does not count and is reported beside the reading. A fall of output with no published reason is reported as unattributed and does not change the branch. A document published after 8 December about days of the window is reported on 24 December as a late correction. The reading names, for each source, who opened it (a person in a browser, or an agent) and on which date. If the operator's page was not opened, the fourth branch is recorded as 'no document found in dispatches and unavailability messages; operator's page not opened' and stays provisional until a person opens it. Read beside the branch and not defining it: Grand Est nuclear output, mean of the daily means of 12 November to 7 December 2026, read on 8 December 2026, against 2,548.8 to 8,574.9 MW; the regional series cannot separate this branch from the next. Indicators: Lowest 12-day mean of the Meuse daily flows at Chooz, DREAL gauge B720000001, 12 November to 7 December 2026, as published on 8 December 2026; Number of published documents dated 12 November to 7 December 2026 that attribute a stop or a power reduction of a Chooz unit to the Meuse flow, the 1998 agreement or the limit on evaporated water, as they stand on 8 December 2026; one document at any of the three kinds of source (operator's Chooz news page, news-agency dispatch, grid unavailability message stating the cause) counts; Source read for the same count, not a separate condition: the grid operator's public page of generation unavailability messages, Chooz 1 and Chooz 2, read in a browser; Read beside, not defining the branch: the same lowest 12-day mean on the operator's gauge B720000004; a difference of branch between the two gauges is reported as such; Read beside, not defining the branch: Grand Est nuclear output, mean of the daily means of 12 November to 7 December 2026, read on 8 December 2026, against 2,548.8 to 8,574.9 MW.

OPEN · confidence high · horizon 2026-12-08. The lowest 12-day mean of the Meuse at Chooz between 12 November and 7 December 2026 is at or above 22 m3/s, and no published document attributes a stop or a power reduction of a Chooz unit between the same dates to the Meuse flow. The branch states that nothing was published, not that nothing happened. Seasonal precedent: every year from 2015 to 2025, lowest value of these dates 28.8 m3/s, none of them starting from a base flow near 20 m3/s. Reading rule for the flow: Hub'Eau, lowest value of the 12-day mean of the daily mean flows (QmnJ) on any day from 12 November to 7 December 2026, read on 8 December 2026 with the values as then published (raw or pre-validated). The Hub'Eau query carries no end date and returns the values published to the day it is opened. If a daily value is missing on that day, the reading is made on the values published and is void if no 12-day mean of the window can be formed. The DREAL gauge B720000001 decides the branch; the operator's gauge B720000004 is read beside it and a difference of branch between the two is reported as such. Neither gauge subtracts the evaporated flow: the downstream value of the rule is lower by up to 2.1 m3/s with two units running, so a reading from 22 to 24.1 leaves it undetermined. The four branches of this reading are read in the order written (lowest mean under 20; from 20 to under 22; at or above 22 with a published flow-linked measure; at or above 22 with none) and the first whose condition holds is the branch. A 12-day mean under 22 m3/s or a measure dated 8 to 31 December 2026 belongs to no branch: those days are read in a follow-up, and the branch read on 8 December stands. Reading rule for the measure, as it stands on 8 December 2026: at least one published document dated 12 November to 7 December 2026 that reports a stop or a power reduction of a Chooz unit, whatever its size or duration, and names the Meuse flow, the 1998 agreement or the limit on evaporated water as its reason. One document at any of three kinds of source counts: a notice on the operator's Chooz news page (https://www.edf.fr/la-centrale-nucleaire-de-chooz/les-actualites-de-la-centrale-nucleaire-de-chooz), opened in an ordinary browser (the page refuses automated readers), its title, date and sentence copied into the reading; a news-agency dispatch as republished by the regional and national press (no single public feed: the reading names the titles searched); or a generation unavailability message for Chooz 1 or Chooz 2 that states the cause, on the grid operator's public page of unavailability messages (https://iip.cloud-rte-france.com/production-unavailability; opened once on 12 November 2026: it answers an automated reader, but its messages load by script and are read in a browser). A trade-press article alone does not count and is reported beside the reading. A fall of output with no published reason is reported as unattributed and does not change the branch. A document published after 8 December about days of the window is reported on 24 December as a late correction. The reading names, for each source, who opened it (a person in a browser, or an agent) and on which date. If the operator's page was not opened, the fourth branch is recorded as 'no document found in dispatches and unavailability messages; operator's page not opened' and stays provisional until a person opens it. If no such document exists on 8 December, this branch holds. Read beside the branch and not defining it: Grand Est nuclear output, mean of the daily means of 12 November to 7 December 2026, read on 8 December 2026, against 3,998.8 to 8,574.9 MW; that band tests the six other units of the region, not the river. Indicators: Lowest 12-day mean of the Meuse daily flows at Chooz, DREAL gauge B720000001, 12 November to 7 December 2026, as published on 8 December 2026; Number of published documents dated 12 November to 7 December 2026 that attribute a stop or a power reduction of a Chooz unit to the Meuse flow, the 1998 agreement or the limit on evaporated water, as they stand on 8 December 2026; one document at any of the three kinds of source (operator's Chooz news page, news-agency dispatch, grid unavailability message stating the cause) counts; Source read for the same count, not a separate condition: the grid operator's public page of generation unavailability messages, Chooz 1 and Chooz 2, read in a browser; Read beside, not defining the branch: the same lowest 12-day mean on the operator's gauge B720000004; a difference of branch between the two gauges is reported as such; Read beside, not defining the branch: Grand Est nuclear output, mean of the daily means of 12 November to 7 December 2026, read on 8 December 2026, against 3,998.8 to 8,574.9 MW.

OPEN · confidence medium · horizon 2027-05-05. The mean daily flow of the Meuse at Chooz in April 2027 is below 90 m3/s. Years on file under 90: 2017 (no day of the 12-day mean under 22 that summer), 2025 (3 days) and 2026 (103 days). Reading rule: Hub'Eau station B720000001, arithmetic mean of the daily mean flows (QmnJ) of 1 to 30 April 2027, read on 5 May 2027 with the values as then published. The Hub'Eau query carries no end date and returns the values published to the day it is opened. If a daily value is missing on that day, the mean is taken on the April days published and their number is stated; the reading is void if none is published. The three branches of this reading are read in the order written (below 90; from 90 to below 150; at or above 150) and the first whose condition holds is the branch. April means on file: 67.9 (2017), 70.4 (2025), 85.0 (2026), 97.6 (2021), 105.7 (2020), 116.0 (2019), 121.8 (2022), 156.9 (2015), 177.5 (2018), 186.1 (2016), 233.0 (2024), 238.7 (2023). The April mean is a starting level, not a reading of the summer: it does not separate the episode years from the others (67.9 in 2017 with no day under 22; 105.7 in 2020 with 46 days). Read beside the branch and not defining it: the May 2027 mean flow, read on 5 June 2027, against 42.7 to 60.5 m3/s, the range of the precedent years; the May ranges of the three branches overlap. Indicators: Mean of the daily mean flows of the Meuse at Chooz, 1 to 30 April 2027, DREAL gauge B720000001, as published on 5 May 2027; Read beside, not defining the branch: mean of the daily mean flows of May 2027 at the same gauge, read on 5 June 2027, against 42.7 to 60.5 m3/s.

OPEN · confidence medium · horizon 2027-05-05. The mean daily flow of the Meuse at Chooz in April 2027 is below 150 m3/s and at or above 90 m3/s. Years on file in this band: 2019 (21 days of the 12-day mean under 22), 2020 (46), 2021 (0) and 2022 (38). Reading rule: Hub'Eau station B720000001, arithmetic mean of the daily mean flows (QmnJ) of 1 to 30 April 2027, read on 5 May 2027 with the values as then published. The Hub'Eau query carries no end date and returns the values published to the day it is opened. If a daily value is missing on that day, the mean is taken on the April days published and their number is stated; the reading is void if none is published. The three branches of this reading are read in the order written (below 90; from 90 to below 150; at or above 150) and the first whose condition holds is the branch. April means on file: 67.9 (2017), 70.4 (2025), 85.0 (2026), 97.6 (2021), 105.7 (2020), 116.0 (2019), 121.8 (2022), 156.9 (2015), 177.5 (2018), 186.1 (2016), 233.0 (2024), 238.7 (2023). The April mean is a starting level, not a reading of the summer: it does not separate the episode years from the others (67.9 in 2017 with no day under 22; 105.7 in 2020 with 46 days). Read beside the branch and not defining it: the May 2027 mean flow, read on 5 June 2027, against 57.5 to 105.3 m3/s, the range of the precedent years; the May ranges of the three branches overlap. Indicators: Mean of the daily mean flows of the Meuse at Chooz, 1 to 30 April 2027, DREAL gauge B720000001, as published on 5 May 2027, upper bound; Mean of the daily mean flows of the Meuse at Chooz, 1 to 30 April 2027, DREAL gauge B720000001, as published on 5 May 2027, lower bound; Read beside, not defining the branch: mean of the daily mean flows of May 2027 at the same gauge, read on 5 June 2027, against 57.5 to 105.3 m3/s.

OPEN · confidence medium · horizon 2027-05-05. The mean daily flow of the Meuse at Chooz in April 2027 is at or above 150 m3/s. Years on file at or above 150: 2015, 2016, 2018, 2023 and 2024, none with a day of the DREAL 12-day mean under 22; in 2018 a unit was nevertheless stopped in autumn. Reading rule: Hub'Eau station B720000001, arithmetic mean of the daily mean flows (QmnJ) of 1 to 30 April 2027, read on 5 May 2027 with the values as then published. The Hub'Eau query carries no end date and returns the values published to the day it is opened. If a daily value is missing on that day, the mean is taken on the April days published and their number is stated; the reading is void if none is published. The three branches of this reading are read in the order written (below 90; from 90 to below 150; at or above 150) and the first whose condition holds is the branch. April means on file: 67.9 (2017), 70.4 (2025), 85.0 (2026), 97.6 (2021), 105.7 (2020), 116.0 (2019), 121.8 (2022), 156.9 (2015), 177.5 (2018), 186.1 (2016), 233.0 (2024), 238.7 (2023). The April mean is a starting level, not a reading of the summer: it does not separate the episode years from the others (67.9 in 2017 with no day under 22; 105.7 in 2020 with 46 days). Read beside the branch and not defining it: the May 2027 mean flow, read on 5 June 2027, against 86.9 to 174.0 m3/s, the range of the precedent years; the May ranges of the three branches overlap. Indicators: Mean of the daily mean flows of the Meuse at Chooz, 1 to 30 April 2027, DREAL gauge B720000001, as published on 5 May 2027; Read beside, not defining the branch: mean of the daily mean flows of May 2027 at the same gauge, read on 5 June 2027, against 86.9 to 174.0 m3/s.

OPEN · confidence low · horizon 2028-01-04. In 2027 the DREAL 12-day mean of the Meuse at Chooz is under 22 m3/s on 46 days or more. Precedents: 2020 and 2026, two of twelve years. Reading rule: Hub'Eau station B720000001, number of days between 1 January and 31 December 2027 on which the 12-day mean of the daily flows is under 22 m3/s, read on 4 January 2028 with the values as then published; days after 31 October count (none on file from 2015 to 2026). The Hub'Eau query carries no end date and returns the values published to the day it is opened. If daily values are missing on that day, the count is made on the 12-day means that can be formed and the days without one are stated; the reading is void if no 12-day mean can be formed. The three branches of this reading are read in the order written (46 days or more; 1 to 45; none) and the first whose condition holds is the branch. Counts on file: 0 in 2015 to 2018, 2021, 2023 and 2024; 21 (2019), 46 (2020), 38 (2022), 3 (2025), 103 (2026). Read beside the branch and not defining it: the days under 24.1 m3/s, the edge of the regulatory zone with two units running (31 in 2018, then 38, 55, 56, 16 and 112 for the same years). The output withheld at Chooz over 2027 is an order of magnitude and is not scored. Indicators: Number of days of 2027 with the 12-day mean of the Meuse daily flows at Chooz under 22 m3/s, DREAL gauge B720000001, as published on 4 January 2028; Read beside, not defining the branch: number of days of 2027 with the same 12-day mean under 24.1 m3/s.

OPEN · confidence medium · horizon 2028-01-04. In 2027 the DREAL 12-day mean of the Meuse at Chooz is under 22 m3/s on 1 to 45 days. Precedents: 2019, 2022 and 2025, three of twelve years. Reading rule: Hub'Eau station B720000001, number of days between 1 January and 31 December 2027 on which the 12-day mean of the daily flows is under 22 m3/s, read on 4 January 2028 with the values as then published; days after 31 October count (none on file from 2015 to 2026). The Hub'Eau query carries no end date and returns the values published to the day it is opened. If daily values are missing on that day, the count is made on the 12-day means that can be formed and the days without one are stated; the reading is void if no 12-day mean can be formed. The three branches of this reading are read in the order written (46 days or more; 1 to 45; none) and the first whose condition holds is the branch. Counts on file: 0 in 2015 to 2018, 2021, 2023 and 2024; 21 (2019), 46 (2020), 38 (2022), 3 (2025), 103 (2026). Read beside the branch and not defining it: the days under 24.1 m3/s, the edge of the regulatory zone with two units running (31 in 2018, then 38, 55, 56, 16 and 112 for the same years). The output withheld at Chooz over 2027 is an order of magnitude and is not scored. Indicators: Number of days of 2027 with the 12-day mean of the Meuse daily flows at Chooz under 22 m3/s, DREAL gauge B720000001, as published on 4 January 2028, lower bound; Number of days of 2027 with the 12-day mean of the Meuse daily flows at Chooz under 22 m3/s, DREAL gauge B720000001, as published on 4 January 2028, upper bound; Read beside, not defining the branch: number of days of 2027 with the same 12-day mean under 24.1 m3/s.

OPEN · confidence medium · horizon 2028-01-04. In 2027 the DREAL 12-day mean of the Meuse at Chooz is under 22 m3/s on no day. Precedents: seven of twelve years; six of them have no day under 24.1 m3/s either and no reported loss; the seventh, 2018, has 31 days under 24.1 and a reported stop. Reading rule: Hub'Eau station B720000001, number of days between 1 January and 31 December 2027 on which the 12-day mean of the daily flows is under 22 m3/s, read on 4 January 2028 with the values as then published; days after 31 October count (none on file from 2015 to 2026). The Hub'Eau query carries no end date and returns the values published to the day it is opened. If daily values are missing on that day, the count is made on the 12-day means that can be formed and the days without one are stated; the reading is void if no 12-day mean can be formed. The three branches of this reading are read in the order written (46 days or more; 1 to 45; none) and the first whose condition holds is the branch. Counts on file: 0 in 2015 to 2018, 2021, 2023 and 2024; 21 (2019), 46 (2020), 38 (2022), 3 (2025), 103 (2026). Read beside the branch and not defining it: the days under 24.1 m3/s, the edge of the regulatory zone with two units running (31 in 2018, then 38, 55, 56, 16 and 112 for the same years). The output withheld at Chooz over 2027 is an order of magnitude and is not scored. Indicators: Number of days of 2027 with the 12-day mean of the Meuse daily flows at Chooz under 22 m3/s, DREAL gauge B720000001, as published on 4 January 2028; Read beside, not defining the branch: number of days of 2027 with the same 12-day mean under 24.1 m3/s.

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Bundesnetzagentur | SMARD.de — CC BY 4.0: "Als Namensnennung ist \"Bundesnetzagentur | SMARD.de\" zu verwenden." Market data on SMARD are published under Creative Commons Namensnennung 4.0 International. Wholesale prices are an exception under review: "Wir überprüfen rechtliche Fragen zur Lizenzierung der Großhandelspreise derzeit umfassend im Rahmen des aktuellen Festlegungsverfahrens HEDWIG." Wholesale price series are therefore marked RESTRICTED per series. (policy, checked 2026-11-12)

Elia (Belgian transmission system operator) — Open Data Portal — Elia Open Data License: "The data provided for are governed by Creative Commons Attribution 4.0 International Public License ("Public License" or "CC BY 4.0"). This Public License is governed by Belgian law." (policy, checked 2026-11-12)

RTE, via Open Data Réseaux Énergies (ODRÉ) — éCO2mix — Dataset metadata of the four éCO2mix datasets used (national and regional, consolidated and real time): licence "Licence Ouverte v2.0 (Etalab)", publisher "RTE". Licence text: "Le « Réutilisateur » est libre de réutiliser l'« Information » : […] de la communiquer, la diffuser, la redistribuer, la publier et la transmettre, de l'exploiter à titre commercial", subject to naming the source and the date of last update. (policy, checked 2026-11-12)

Hub'Eau, Eaufrance (SCHAPI, DREAL, CNR) — hydrométrie — Conditions générales Hub'Eau, Licence Ouverte Etalab: "Les Jeux de données sont donc librement et gratuitement utilisables et réutilisables, y compris dans un but commercial. L'utilisateur de ces données doit néanmoins veiller à citer l'auteur des Jeux de données." (policy, checked 2026-11-11)