Ille-et-Vilaine (35)
Retiers: geology and natural hazards
What public services say about the ground beneath the commune (population 4,566) 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
Retiers at a glance
- Seismic zone
- 2 of 5 (low)
- Radon potential
- Category 3 of 3 (significant potential)
- Recognised natural disasters
- 8 since 1983
- Underground cavities recorded
- None
- Ground movements recorded
- None
- Risk prevention plans
- None
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 à débordement lent de cours d’eau
- Séisme
- Phénomène lié à l’atmosphère: tempête et grains (vent)
- Transport de marchandises dangereuses
Recognised natural disasters
8 events recognised as a natural disaster by ministerial order since 1983.
- Inondations et/ou coulées de boue: 7
- Mouvement de terrain: 2
- Tempête: 1
Inondations et/ou coulées de boue
Event from 23/01/2025 to 05/02/2025, order published in the Journal officiel on 08/02/2025.
Inondations et/ou coulées de boue
Event from 17/06/2024 to 21/06/2024, order published in the Journal officiel on 07/07/2024.
Inondations et/ou coulées de boue
Event from 23/12/2013 to 24/12/2013, order published in the Journal officiel on 02/02/2014.
Mouvement de terrain, Inondations et/ou coulées de boue
Event from 25/12/1999 to 29/12/1999, order published in the Journal officiel on 30/12/1999.
Inondations et/ou coulées de boue
Event on 01/06/1999, order published in the Journal officiel on 20/10/1999.
Inondations et/ou coulées de boue
Event from 17/01/1995 to 31/01/1995, order published in the Journal officiel on 08/02/1995.
Tempête
Event from 15/10/1987 to 16/10/1987, order published in the Journal officiel on 24/10/1987.
Mouvement de terrain, Inondations et/ou coulées de boue
Event on 18/07/1983, order published in the Journal officiel on 18/11/1983.
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 3 of 3: significant potential. At least part of the commune has higher-than-average uranium content. 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.
No underground cavity recorded (quarries, cellars, military works, natural cavities…).
No ground movement recorded (landslides, rockfalls, collapses, mudflows…).
Risk prevention plans
No risk prevention plan is listed for the commune.
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.