Skip to main content
Français

Bouches-du-Rhône (13)

Trets: geology and natural hazards

What public services say about the ground beneath the commune (population 10,946) and the hazards it faces: natural disasters, earthquakes, radon, cavities, clays, groundwater and rocks.

Hazard names and other data are quoted as their producers publish them, in French.

Explore the commune on the map

Hazards listed by the French State

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: affaissements et effondrements d’origine anthropique (anciennes carrières souterraines, hors mines), eboulement ou chutes de pierres et de blocs, glissement de terrain, tassements différentiels
  • Séisme
  • Feu de forêt
  • Transport de marchandises dangereuses
  • Affaissement minier: effondrements généralisés

Recognised natural disasters

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

  • Sécheresse: 13
  • Inondations et/ou coulées de boue: 7
  • Secousse sismique: 1
  • Tempête: 1

  1. Inondations et/ou coulées de boue

    Event on 13/06/2023, order published in the Journal officiel on 20/10/2023.

  2. Sécheresse

    Event from 01/04/2023 to 30/06/2023, order published in the Journal officiel on 02/07/2024.

  3. Inondations et/ou coulées de boue

    Event on 01/11/2022, order published in the Journal officiel on 30/12/2022.

  4. Sécheresse

    Event from 01/04/2022 to 30/09/2022, order published in the Journal officiel on 03/05/2023.

  5. Sécheresse

    Event from 01/04/2021 to 30/09/2021, order published in the Journal officiel on 05/08/2022.

  6. Inondations et/ou coulées de boue

    Event from 22/10/2019 to 23/10/2019, order published in the Journal officiel on 19/12/2019.

  7. Sécheresse

    Event from 01/04/2019 to 30/09/2019, order published in the Journal officiel on 03/09/2020.

  8. Sécheresse

    Event from 01/04/2017 to 30/09/2017, order published in the Journal officiel on 27/07/2018.

  9. Sécheresse

    Event from 01/04/2016 to 31/12/2016, order published in the Journal officiel on 01/09/2017.

  10. Inondations et/ou coulées de boue

    Event on 13/10/2014, order published in the Journal officiel on 19/02/2015.

  11. Inondations et/ou coulées de boue

    Event from 14/12/2008 to 15/12/2008, order published in the Journal officiel on 22/04/2009.

  12. Sécheresse

    Event from 01/07/2007 to 30/09/2007, order published in the Journal officiel on 13/08/2008.

  13. Sécheresse

    Event from 01/01/2007 to 31/03/2007, order published in the Journal officiel on 13/08/2008.

  14. Sécheresse

    Event from 01/01/2002 to 30/06/2002, order published in the Journal officiel on 22/05/2003.

  15. Inondations et/ou coulées de boue

    Event on 07/09/1998, order published in the Journal officiel on 13/01/1999.

  16. Sécheresse

    Event from 01/04/1998 to 30/06/1998, order published in the Journal officiel on 29/12/2000.

  17. Sécheresse

    Event from 01/10/1993 to 31/03/1998, order published in the Journal officiel on 22/08/1998.

  18. Sécheresse

    Event from 01/01/1992 to 30/09/1993, order published in the Journal officiel on 17/03/1995.

  19. Sécheresse

    Event from 01/05/1989 to 31/12/1991, order published in the Journal officiel on 03/09/1993.

  20. Secousse sismique

    Event from 19/02/1984 to 20/02/1984, order published in the Journal officiel on 24/05/1984.

  21. 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.

Earthquakes and radon

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.

Beneath the town hall

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

Cavities and ground movements

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

9 underground cavities recorded (quarries, cellars, military works, natural cavities…).

No ground movement recorded (landslides, rockfalls, collapses, mudflows…).

See cavities and ground movements on the map

Risk prevention plans

  • PPRN-RGA - Trets 2007

    Natural risk prevention plan.

  • PPRN-IF - Trets 2016

    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.

Nearby communes

Sources and limitations

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.