Photo: Clémenceau Lauret · CC BY-SA 4.010% of Saint-Pierre’s residents live in a mapped flood zone
The state lists a volcano risk here: Piton de la Fournaise. Hazard risk is not graded in France: there is no national flood map, so a town outside the mapped areas can’t be called safe from floods.
What stands out about hazards in Saint-Pierre
From the state’s records on Géorisques. Nothing here is graded.
5 hazards in Saint-Pierre at a glance
Bars show where the town sits among French towns of 2,500+; they are not a grade. Disaster declarations are shown, not compared.
Flood zones
Disasters declared
Earthquakes
Radon
Cyclones
Why hazards aren’t graded in France
In the UK, the Hazard risk grade is the share of homes in a mapped flood zone; in the U.S., it is FEMA’s modelled yearly damage to buildings. Both rest on maps that cover the whole country. France maps flood zones in detail only in its 125 areas at highest risk (TRI), so most towns have no figure, and a blank would read as “dry”. The state’s disaster declarations don’t fill the gap: they depend on the mayor applying, and they don’t line up with the mapped zones. So Saint-Pierre has no Hazard grade, and its overall grade uses the other six subjects.
Everything on this page is shown as published. We’ll grade it when France publishes a national flood map.
Flood zones in Saint-Pierre on the map
The state’s own layers from Géorisques, drawn over the street map. Tap a layer to switch it on or off.
Flood zones are drawn only inside the state’s mapped areas (TRI, pink outline). Outside them, the map is blank because nobody has drawn it, not because the ground is dry.
10% of Saint-Pierre’s residents live in a mapped flood zone
Residents in the state’s medium-probability flood zones, by where the water comes from. Mapped areas only.
Share of residents in a medium-probability flood zone. Saint-Pierre has more than 77% of mapped towns. The other 2,833 towns of 2,500+ have no detailed map.
| # | Town | People | In a flood zone | |
|---|---|---|---|---|
| 1 | Lyon 8e Rhône | 85,943 | 0% | |
| 2 | Paris 10e Paris | 83,873 | 0% | |
| 3 | Lyon 7e Rhône | 88,326 | 0% | |
| … | ||||
| 31 | Cherbourg-en-Cotentin Manche | 78,258 | 9.2% | |
| 32 | Marseille 8e Bouches-du-Rhône | 84,683 | 9.8% | |
| 33 | Saint-Pierre Réunion | 85,038 | 10% | |
| 34 | Rueil-Malmaison Hauts-de-Seine | 82,874 | 20% | |
| 35 | Vitry-sur-Seine Val-de-Marne | 93,963 | 23% | |
| … | ||||
| 40 | Colombes Hauts-de-Seine | 91,053 | 34% | |
| 41 | Avignon Vaucluse | 92,188 | 41% | |
Mapped area: – (flood directive maps, 2nd cycle, 2020). Medium probability is roughly the 1-in-100-year flood. Residents placed by INSEE’s 200 m income grid (2021).
20 natural disasters declared in Saint-Pierre since 1982, 17 for floods
The state’s register of natural-disaster orders, 1982 to January 2026.
- 2025Floods and mudflowsFebruary 26–28, 2025 · order published April 28, 2025
- 2024Floods and mudflowsJanuary 28–29, 2024 · order published April 7, 2024
- 2024Wave impact on the coast · Floods and mudflowsJanuary 13–15, 2024 · order published January 23, 2024
- 2022Wave impact on the coastJune 28–29, 2022 · order published October 29, 2022
- 2022Floods and mudflowsFebruary 2–4, 2022 · order published February 13, 2022
- 2018Floods and mudflowsApril 23–24, 2018 · order published June 22, 2018
Show all 15 events
- 2018Ground movementJanuary 18, 2018 · order published February 1, 2018
- 2018Floods and mudflowsJanuary 17–18, 2018 · order published February 1, 2018
- 2014Floods and mudflowsJanuary 1–3, 2014 · order published January 18, 2014
- 2009Floods and mudflowsApril 5, 2009 · order published July 1, 2009
- 2007Wave impact on the coastMay 12–13, 2007 · order published November 16, 2007
- 2007Floods and mudflowsFebruary 26–27, 2007 · order published March 28, 2007
- 2002Wave impact on the coast · Floods and mudflows · Ground movementJanuary 22–23, 2002 · order published April 18, 2002
- 1994Floods and mudflowsFebruary 10–12, 1994 · order published April 23, 1994
- 1993Wave impact on the coast · Floods and mudflows · Ground movementJanuary 18–20, 1993 · order published June 12, 1993
Declarations by hazard · 1982–2025
Each line is a state order recognizing a natural disaster in the commune (“CatNat”), which lets insured owners claim. The latest flood began February 26, 2025; 14 flood declarations since 1995.
This count partly reflects how often a mayor applies for a declaration, so it isn’t compared between towns. It is a record of recognized claims, not a flood map. Source: GASPAR, Géorisques, file of 5 October 2026 (orders published to January 2026).
The state lists 9 hazards for Saint-Pierre
Risk plans in force or in preparation, and the prefecture’s list of major risks.
| Hazard | Risk plan (PPR) | Listed by the prefecture |
|---|---|---|
| River flooding and runoff | Approved 2016 | ✓ |
| Coastal flooding | Approved 2018 | — |
| Landslides and rockfalls | Approved 2018 | ✓ |
| Earthquake | — | ✓ |
| Volcano | — | ✓ |
| Cyclone and storm | — | ✓ |
| Severe weather | — | ✓ |
| Forest fire | — | ✓ |
| Dangerous goods in transit | — | ✓ |
A risk plan (plan de prévention des risques, PPR) is the state’s map of where building is banned or restricted because of a hazard; it is attached to the town’s planning rules, and a seller or landlord must tell you if the home is in one. The prefecture’s file of major risks (DDRM) lists the hazards it expects in each commune.
Plans: PPR i+mvt Saint Pierre · PPR littoraux -Saint Pierre
Earthquake zone 2 (low)
What the ground under Saint-Pierre does: national maps, the same for every town.
The national clay map (BRGM 2025) covers mainland France and Corsica only; overseas départements have none.
Saint-Pierre is in zone 2 (low). New buildings must follow the earthquake building code (Eurocode 8) for their type. The zone sets building rules; it isn’t a forecast.
Clay: BRGM shrink-swell exposure map 2025, residents placed by INSEE’s 200 m grid. Earthquakes: national seismic zoning, decree of 22 October 2010.
Radon potential in Saint-Pierre: category 1 of 3 (low)
Radon is a natural radioactive gas from granite and volcanic rock; it builds up indoors.
Saint-Pierre is in category 1, the lowest: the rocks here release little radon.
The category describes the rocks under the commune, not any home: a test is the only way to know.
Source: radon potential by commune, IRSN (now ASNR), 2019.
No industrial risk plan reaches Saint-Pierre
Hazardous sites whose danger zone reaches the town, and the technological risks the prefecture lists.
| Dangerous goods in transit | road, rail, pipeline or waterway through the town |
Seveso sites store or use large amounts of dangerous substances; upper-tier sites have a risk plan around them. Distances are from the town’s center.
Sources: GASPAR (PPRT, DDRM), Géorisques, 5 October 2026; Seveso sites from Géorisques’ register of classified installations.
Volcano, cyclones and earthquakes in Saint-Pierre
The hazards that set the overseas départements apart, as the state records them; not graded.
In a cyclone or volcanic alert, Météo-France and the prefecture set the alert level (yellow, orange, red, then violet for a cyclone); FR-Alert sends it to every phone in the area.
Hazards in Saint-Pierre’s neighbors
Towns of 2,500+ within 30 km. Tap one to open its hazards page.
| Town | Flood zone* | Seismic zone | Radon |
|---|---|---|---|
| Saint-Pierre | 10% | 2 | 1 |
| Le Tampon 82,579 · 8 km | 7.8% | 2 | 1 |
| Saint-Louis 54,941 · 8 km | — | 2 | 1 |
| Entre-Deux 7,176 · 8 km | — | 2 | 1 |
| Petite-Île 13,067 · 9 km | — | 2 | 1 |
| L'Étang-Salé 14,464 · 14 km | — | 2 | 1 |
| Saint-Joseph 39,207 · 16 km | 5.8% | 2 | 1 |
* Share of residents in a mapped medium-probability flood zone; a dash means no detailed map, not no risk. Radon: category 1 to 3.
Being ready in Saint-Pierre
Where France publishes warnings, and what to ask before you buy or rent.
- Météo-France’s vigilance map gives the day’s warnings, from yellow to red (violet for a cyclone).
- FR-Alert sends emergency alerts to every phone in the area; no sign-up needed.
- The seller or landlord must give you a risk statement (état des risques) for the address, listing the plans it is in.
- They must also tell you about any natural-disaster claim paid on the home.
- Géorisques gives the same statement for any address, free.
- Keep water, food, a radio and batteries for several days in cyclone season.
- The volcano observatory publishes Piton de la Fournaise’s alert level.
- The town hall’s safety plan (PCS) names the shelters.
- Ask for the risk statement and read which plans the address is in.
- Ask the town hall for its risk booklet (DICRIM) and safety plan (PCS).
- Check that home insurance includes natural-disaster cover (it comes with fire cover).
What this data can and can’t tell you
- Not graded. France has no national flood map, so we don’t grade hazard risk. Comparisons on this page are with other French towns of 2,500+, shown for context.
- Mapped areas only. Flood shares exist only where the state has mapped flooding in detail (the TRI areas). A town without a figure has no map, not no risk.
- Disaster declarations. A CatNat order recognizes a disaster so that insurers pay; it follows the commune’s application. The count partly reflects how often a mayor applies, so we show it but don’t compare towns on it.
- Plans. A risk plan maps where building is limited; it doesn’t say any one home will flood.
- Clay, earthquakes, radon. National maps of the ground: they describe susceptibility and set building rules, not damage or forecasts.
Questions about hazards in Saint-Pierre
Does Saint-Pierre flood?
The state has declared 17 flood disasters in Saint-Pierre since 1982, the last starting February 26, 2025. On the state’s detailed map, 10% of residents live in a medium-probability flood zone. A flood risk plan is in force.
Is Saint-Pierre at risk of earthquakes?
Saint-Pierre is in seismic zone 2 of 5 (low). The zone sets building rules for new construction; it isn’t a forecast.
Is there radon in Saint-Pierre?
Radon potential is category 1 of 3 (low). It describes the ground under the commune; only a test tells you a home’s level.
Are there dangerous industrial sites near Saint-Pierre?
No industrial risk plan reaches Saint-Pierre, and no Seveso site lies within 5 km.
Is Saint-Pierre at risk from the volcano and cyclones?
The prefecture lists Piton de la Fournaise and cyclones among Saint-Pierre’s major risks. The Piton de la Fournaise volcano observatory (OVPF-IPGP) publishes the volcano’s alert level; Météo-France issues cyclone warnings.
Why doesn’t Saint-Pierre have a Hazard grade?
France maps flood zones in detail only in its areas at highest risk, so most towns would have no figure, and a blank would look like no risk. We show the data instead, and will grade it if France publishes a national flood map.
Sources: Géorisques (Ministry of Ecological Transition), GASPAR file of 5 October 2026: CatNat orders, risk plans (PPRN, PPRT, PPRM), flood atlases, DDRM, DICRIM · flood directive maps, 2020 (TRI 2nd cycle) and 2024 outlines · BRGM clay shrink-swell map 2025 · seismic zoning, decree of 22 October 2010 · ASNR (formerly IRSN) radon potential 2019 · INSEE 200 m income grid 2021 (where residents live) · map: Géorisques layers over © OpenStreetMap contributors · Seveso sites: Géorisques register of classified installations. Licence Ouverte / Open Licence (Etalab). Not graded.
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.