The commune of Mourèze has identified eight major hazards on its territory, documented in the Municipal Emergency Plan (PCS) version 2.0, adopted on 21 April 2026. Each fact sheet presents the risk level, its priority rating and the recommended actions to take.
Forest fire
HIGH
PRIORITY
Mourèze is classified as a very high forest fire risk zone. The limestone massif and surrounding garrigue scrubland are particularly exposed. Dry summers and strong winds (tramontane, westerly winds) can cause rapid fire spread. The peak risk period runs from June to September.
What to do
- During red or orange fire warnings: avoid wooded areas and garrigue scrubland.
- Never light a fire outdoors, including barbecues, in at-risk areas.
- If you see a fire starting, immediately call 18 (fire brigade).
- If an evacuation is ordered by authorities, leave the area without delay using the indicated routes.
- Do not return to the area without authorisation from emergency services.
Heatwave and drought
MEDIUM
PRIORITY
The Hérault department is one of the most affected by heatwave episodes in France. Extreme summer heat poses a major risk to vulnerable people (elderly, young children, isolated individuals) and to the many tourists engaging in outdoor activities at the Cirque de Mourèze.
What to do
- Drink water regularly, even if you do not feel thirsty.
- Avoid strenuous physical activity between 12pm and 4pm.
- Stay in cool rooms or find an air-conditioned space.
- Regularly check on elderly, isolated or vulnerable people around you.
- Hiking: carry at least 1.5 litres of water per hour of activity and wear a hat.
- Report anyone in distress to 15 (SAMU medical emergency).
Flooding
MEDIUM
SECONDARY
The municipality is traversed by watercourses subject to Cévenol flow regimes, characterized by sudden, violent flash floods, particularly in autumn (September to November). The Rats and Nougarède streams can quickly overflow their banks during heavy rainfall.
What to do
- Never drive through a flooded road or underpass (30 cm of water is enough to sweep away a vehicle).
- Move to upper floors or high ground; never go down to a cellar or basement.
- Turn off gas and electricity before evacuating.
- Do not cross bridges during a flood.
- Follow instructions from the authorities (radio, municipal siren).
Severe storm
MEDIUM
SECONDARY
The commune is exposed to violent winds (tramontane, sea wind, Mediterranean squalls) that can exceed 100 km/h. These events may cause falling trees, broken power lines and roof damage.
What to do
- Secure or bring indoors any objects that could be blown away (garden furniture, parasols).
- Stay indoors, away from windows, trees and cliff edges.
- Do not park your vehicle under trees or power lines.
- If a power line falls, do not approach it and call 18.
Hazardous materials transport
LOW
SECONDARY
Roads near the commune (RD 908 and inter-municipal routes) carry vehicles transporting hazardous materials (hydrocarbons, chemicals, gas). A hazardous materials accident may create a risk of explosion, fire or toxic fume release.
What to do
- Stay at least 200 metres away from the accident site and do not smoke.
- Do not touch any spilled substances and do not attempt to intervene.
- If indoors, close all windows and block ventilation openings.
- Call 18 (fire brigade) or 15 (SAMU) and provide the hazard number and UN number shown on the orange panel of the vehicle.
- Wait for official instructions before leaving your home.
Ground movement
MEDIUM
WATCH
The Cirque de Mourèze consists of dolomitic rocks, some of which are at risk of rockfall, particularly after heavy rain or freeze-thaw cycles. Ground movements may also occur on the clay-limestone slopes of the commune.
What to do
- Strictly respect marked zones and official trails.
- Do not approach cliff edges, particularly in wet weather or after a frost.
- Report any visible collapse or instability to the town hall (04 67 96 08 47) or fire brigade (18).
- In the event of a sudden movement, move away perpendicular to the direction of the fall.
Radon
LOW
INFORMATION
Radon is a naturally occurring radioactive gas produced by the decay of uranium in certain geological substrates. Mourèze is located in an area where radon concentrations may be present in buildings, particularly in cellars and poorly ventilated ground-floor spaces. Long-term radon exposure is the second leading cause of lung cancer in France.
What to do
- Ventilate your premises regularly, especially cellars, basements and ground floors.
- Have the radon concentration measured in your home (test kits available at pharmacies or from IRSN).
- If concentration exceeds 300 Bq/m³, ventilation improvement works are recommended.
- For further information, contact the Agence Régionale de Santé Occitanie.
Seismic activity
LOW
INFORMATION
Mourèze is classified as a low seismic hazard zone (zone 2 on a national scale of 5). Earthquakes in this area can occur but generally remain low in intensity. New buildings are constructed according to seismic safety standards.
What to do
- During a tremor: shelter under a sturdy desk or table, away from windows and exterior walls.
- Do not rush towards stairs or outside during the tremor.
- After the tremor: check gas installations and cut the electricity if visible electrical damage is present.
- Do not use lifts.
- Be aware of aftershocks that may follow the main earthquake.