Tornac: geology and natural hazards

Seismic zone

2 of 5 (low)

Radon potential

Category 2 of 3 (low potential, with aggravating factors)

Recognised natural disasters

13 since 1982

Underground cavities recorded

None

Ground movements recorded

2

Risk prevention plans

1

Natural and technological hazards to which the commune is exposed, according to the national GASPAR database.

• Inondation: par une crue torrentielle ou à montée rapide de cours d’eau
• Mouvement de terrain: glissement de terrain, tassements différentiels
• Séisme
• Feu de forêt
• Radon
• Transport de marchandises dangereuses

13 events recognised as a natural disaster by ministerial order since 1982.

• Inondations et/ou coulées de boue: 10
• Sécheresse: 3
• Tempête: 1

1. Inondations et/ou coulées de boue

   Event from 28/09/2026 to 30/09/2026, order published in the Journal officiel on 22/10/2026.

2. Sécheresse

   Event from 01/07/2022 to 30/09/2022, order published in the Journal officiel on 14/09/2023.

3. Inondations et/ou coulées de boue

   Event from 19/09/2020 to 20/09/2020, order published in the Journal officiel on 24/09/2020.

4. Sécheresse

   Event from 01/07/2017 to 30/09/2017, order published in the Journal officiel on 05/07/2018.

5. Inondations et/ou coulées de boue

   Event from 17/09/2014 to 20/09/2014, order published in the Journal officiel on 27/09/2014.

6. Sécheresse

   Event from 01/03/2012 to 31/12/2012, order published in the Journal officiel on 10/08/2014.

7. Inondations et/ou coulées de boue

   Event from 06/09/2010 to 07/09/2010, order published in the Journal officiel on 05/12/2010.

8. Inondations et/ou coulées de boue

   Event from 08/09/2002 to 10/09/2002, order published in the Journal officiel on 20/09/2002.

9. Inondations et/ou coulées de boue

   Event from 06/10/2001 to 07/10/2001, order published in the Journal officiel on 09/02/2002.

10. Inondations et/ou coulées de boue

    Event from 03/10/1995 to 06/10/1995, order published in the Journal officiel on 07/01/1996.

11. Inondations et/ou coulées de boue

    Event from 21/09/1992 to 23/09/1992, order published in the Journal officiel on 18/11/1992.

12. Inondations et/ou coulées de boue

    Event on 11/10/1988, order published in the Journal officiel on 15/12/1988.

13. Tempête, Inondations et/ou coulées de boue

    Event from 06/11/1982 to 10/11/1982, order published in the Journal officiel on 19/11/1982.

Seismic zone

Zone 2 of 5: low. This regulatory zoning, in force since 2011, sets the rules for earthquake-resistant construction.

Radon potential

Category 2 of 3: low potential, with aggravating factors. Geological features (faults, mine workings, thermal springs) can make it easier for radon to reach buildings. Radon is a naturally occurring radioactive gas that can build up in poorly ventilated rooms.

What BRGM maps say at the town hall. They describe that single point: elsewhere in the commune, the ground may be quite different.

• Shrink-swell clays

• Rising groundwater

• Underground cavities

• Ground movements

• Earthquakes

• Nature of the ground

Recorded across the whole commune by BRGM, in its national databases of underground cavities and ground movements.

No underground cavity recorded (quarries, cellars, military works, natural cavities…).

2 ground movements recorded (landslides, rockfalls, collapses, mudflows…).

See cavities and ground movements on the map

• R111-3 Gardon d’Anduze

  Natural risk prevention plan.

The zoning and regulations of each plan, which may prohibit or restrict building, can be consulted at the town hall and on Géorisques.

• Massillargues-Attuech (30)
• Boisset-et-Gaujac (30)
• Anduze (30)
• Lézan (30)
• Saint-Nazaire-des-Gardies (30)
• Durfort-et-Saint-Martin-de-Sossenac (30)
• Saint-Félix-de-Pallières (30)
• Saint-Jean-de-Crieulon (30)

Listed hazards, natural disasters, seismic zoning, radon potential, cavities, ground movements and prevention plans: Géorisques, published by the French ministry for the ecological transition, under Licence Ouverte Etalab 2.0, data accessed on 02/11/2026. Summary beneath the town hall: BRGM map services, queried when the page is displayed. List of communes and populations: API Découpage administratif (geo.api.gouv.fr), d’après le code officiel géographique de l’Insee, version of 30/10/2026.

This information reflects the state of knowledge at the scale of the commune or of a single point. It replaces neither a soil survey nor the official risk statement (état des risques) required for a sale or a rental, which is drawn up on the official French government service.