Gironde: Underground Hotspots Prolong Response After Major Fire

Lège-Cap-Ferret – 02.08.2026: Following the major fire in Gironde, firefighters are focusing on hidden sources of fire in the ground. Especially in the area around Cap Ferret, peat can retain heat for a long time and allow the fire to spread underground. According to the situation assessment confirmed so far, around 42,000 hectares of forest and vegetation have been affected by the fire. Even though the open flame front is no longer advancing, the area remains dangerous.

Emergency crews must inspect smoking spots, root areas and charred soil individually, open them up and cool them with water. Hotspots can persist beneath a surface that appears to have been extinguished. If temperatures rise again, winds pick up or the ground dries out further, the fire can re-emerge at the surface. This painstaking work differs fundamentally from fighting an open fire front and can continue for an extended period.

Since 22 July, the fire had spread rapidly from Saumos across parts of the northern Bassin d’Arcachon. During the acute phase, authorities and emergency services ordered large-scale evacuations, including on the Lège-Cap-Ferret peninsula. The gendarmerie, fire service and other security forces secured transport routes, assisted residents and cleared areas at risk.

According to the most recently published information, the affected area of around 42,000 hectares has not expanded further. At the end of July, the fire was considered stabilised, but not yet fully secured. The terms refer to different operational phases: stabilisation means that the spread has been halted for the time being. A fire is only fully secured when its perimeter is under lasting control and no further spread is expected.

Peaty soils make this transition considerably more difficult. The organic material can smoulder in deeper layers, even though little more than smoke or isolated heat is visible on the surface. Underground, embers can continue along dry peat and root layers. It is therefore not enough to extinguish visible flames; the affected areas must be checked repeatedly and re-watered if necessary.

For local residents, stabilisation therefore does not yet mean an unrestricted return to normality. Depending on the local risk situation, access to forest areas may remain closed while firefighters and authorities monitor ground temperatures and check for possible flare-ups. The unchanged area of damage shows that the immediate spread has been slowed. At the same time, the ongoing work on underground hotspots demonstrates why fully securing such a fire area takes far longer than extinguishing the visible flames.