Photo: PoM · CC BY-SA 3.0An industrial risk plan reaches into Roura
The ground under Roura can release radon; a test is the only way to know a home’s level. 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 Roura
From the state’s records on Géorisques. Nothing here is graded.
5 hazards in Roura 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
Industrial sites
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 Roura 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 Roura on the map
The state’s own layers from Géorisques, drawn over the street map. Tap a layer to switch it on or off.
Roura is outside the state’s detailed flood maps, so no flood zone shows here; that doesn’t mean no flood risk (below).
No detailed flood map for Roura
The state has mapped flood zones here, but INSEE publishes no residents’ grid for this département, so there is no share of residents to show. That isn’t a clean bill of health: the state has declared 3 flood disasters here since 1982, the last in March 2022.
What the state does have for Roura: a flood risk plan (PPR), which maps the zones where building is restricted, a flood atlas (Atlas des zones inondables de Gu and Cartographie des zones humides d) showing where past floods reached and a mapped area at significant flood risk (Réseau hydrographique de l'Ile de Cayenne).
4 natural disasters declared in Roura since 1982, 3 for floods
The state’s register of natural-disaster orders, 1982 to January 2026.
- 2022Floods and mudflowsMarch 1–23, 2022 · order published April 6, 2022
- 2020Floods and mudflows · Ground movementMay 7–18, 2020 · order published June 6, 2021
- 2000Floods and mudflowsMay 15–25, 2000 · order published December 29, 2000
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 March 1, 2022; 3 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 4 hazards for Roura
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 2002 | ✓ |
| Landslides and rockfalls | — | ✓ |
| Industrial site | Approved 2024 | — |
| 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: PPRI - Roura Cacao · PPRT Montagne des serpents
Earthquake zone 1 (very low)
What the ground under Roura does: national maps, the same for every town.
The national clay map (BRGM 2025) covers mainland France and Corsica only; overseas départements have none.
Roura is in zone 1 (very low): ordinary homes need no earthquake building rules. 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 Roura: category 3 of 3 (significant)
Radon is a natural radioactive gas from granite and volcanic rock; it builds up indoors.
Roura is in category 3: parts of the ground can release significant radon. Since 2018, sellers and landlords here must mention it, and testing a home over two winter months is advised.
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.
Roura is inside an industrial risk plan
Hazardous sites whose danger zone reaches the town, and the technological risks the prefecture lists.
| Montagne des serpents | approved 2024 · Effet de projection |
A PPRT is drawn around every upper-tier Seveso site. It covers each commune its danger zone reaches and limits building there; it measures the danger of an accident, not pollution.
| 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.
Hazards in Roura’s neighbors
Towns of 2,500+ within 30 km. Tap one to open its hazards page.
| Town | Flood zone* | Seismic zone | Radon |
|---|---|---|---|
| Roura | — | 1 | 3 |
| Matoury 36,512 · 14 km | — | 1 | 1 |
| Remire-Montjoly 27,723 · 20 km | — | 1 | 1 |
| Cayenne 62,675 · 23 km | — | 1 | 1 |
| Montsinéry-Tonnegrande 3,626 · 26 km | — | 1 | 3 |
* 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 Roura
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.
- Test over at least two months between September and April.
- Above 300 Bq/m³, air the home and seal the floor.
- 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 Roura
Does Roura flood?
The state has declared 3 flood disasters in Roura since 1982, the last starting March 1, 2022. The town has no detailed flood map, so check a specific address on Géorisques. A flood risk plan is in force.
Is Roura at risk of earthquakes?
Roura is in seismic zone 1 of 5 (very low). The zone sets building rules for new construction; it isn’t a forecast.
Is there radon in Roura?
Radon potential is category 3 of 3 (significant). It describes the ground under the commune; only a test tells you a home’s level.
Are there dangerous industrial sites near Roura?
Roura is inside an industrial risk plan (Montagne des serpents), drawn around a hazardous site whose danger zone reaches the town.
Why doesn’t Roura 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.