EDF sirens: tests at the Castillon and Chaudanne dams from 10 to 20 November 2026

EDF has announced individual tests of the warning sirens of the Castillon and Chaudanne dams from 10 to 20 November 2026, between 2pm and 4pm, outside the usual quarterly tests. These tests follow the upgrade of the 8 sirens of the two dams, scheduled from 9 to 20 November 2026. A siren heard during these hours, around these two dams, may therefore be a test.

At a glance

Dams concerned: Castillon and Chaudanne (Alpes-de-Haute-Provence)
Upgrade: 8 sirens, from 9 to 20 November 2026
Possible tests: from 10 to 20 November 2026, between 2pm and 4pm
Source: EDF, notice of 2 October 2026

What EDF has announced

In its notice of 2 October 2026, EDF states that EDF Hydro Méditerranée is upgrading and renovating the public warning system of the Castillon and Chaudanne dams, 8 sirens in all, in the Alpes-de-Haute-Provence. The work concerns the control units and the means of communication with the sirens, which are moving in particular to a 4G link. EDF attributes it to the obsolescence of the equipment and to the shutdown of the public switched telephone network (RTC), planned for 2030.

Following this work, EDF will check that the sirens trigger correctly, outside the regular statutory tests:

work on the sirens of the Castillon and Chaudanne dams: from 9 to 20 November 2026;
possible individual siren tests: from 10 to 20 November 2026, between 2pm and 4pm.

What these sirens are for

According to EDF, large dams (more than 20 m high and 15 million m³ of stored water) are covered by a specific intervention plan (plan particulier d’intervention, PPI): an emergency plan to protect the population in the event of a serious incident, drawn up and implemented by the prefect with the support of EDF, which includes in particular warning and informing the population. At Castillon and Chaudanne, the warning relies on powerful foghorn-type sirens located in the area immediately around the dams. They are tested every quarter, on the first Wednesday of March, June, September and December.

If you hear a siren

EDF’s notice describes neither the signal of a real alert nor what to do, and LiveVerdon does not write instructions that the source does not give. To find out these instructions, ask the town hall of the municipality where you are staying or the prefecture of the Alpes-de-Haute-Provence.

Frequently asked questions

What are the dates of the siren tests at the Castillon and Chaudanne dams?

EDF has announced that individual siren tests may be carried out from 10 to 20 November 2026, between 2pm and 4pm. The work to upgrade the sirens of these two dams is scheduled from 9 to 20 November 2026.

Why are there tests outside the usual dates?

EDF is renovating the warning system of the two dams: the control units and the means of communication with the sirens, including a switch to a 4G link. It cites the obsolescence of the equipment and the shutdown of the public switched telephone network (RTC), planned for 2030. After this work, EDF checks that the sirens trigger correctly, outside the regular statutory tests.

When are the sirens usually tested?

According to EDF, the system is tested every quarter, on the first Wednesday of March, June, September and December.

What should I do if I hear a siren?

EDF’s notice describes neither the signal of a real alert nor what to do. To find out these instructions, ask the town hall of the municipality where you are staying or the prefecture of the Alpes-de-Haute-Provence.

Is the Serre-Ponçon dam affected?

The same EDF notice also announces the upgrade of the 6 sirens of the Serre-Ponçon dam, in the Hautes-Alpes, outside the Verdon, with possible tests from 27 to 30 October 2026, between 2pm and 4pm.