Val-d'Oise

Recorded Natural Hazards (Géorisques)

It has 183 municipalities and 1,281,653 inhabitants. Under the seismic zoning in force since 2011, its highest seismicity is very low (zone 1 of 5). A natural disaster has been declared 1,291 times since 1982 (one declaration per municipality and decree), mostly for floods (828) and drought (233). The most recent was signed on 23 February 2025. 116 municipalities are covered by an approved natural hazard prevention plan.

Seismicity Zones

Number of municipalities in each zone of the regulatory seismic zoning (from 1, very low, to 5, high).

Natural Disasters Declared Since 1982

Declarations per five-year period.

Most Widespread Events

• 1999Ground Movements · 25 December 1999184 municipalities
• 1999Floods and Mudflows · 25 December 1999184 municipalities
• 1983Floods and Mudflows · 22 June 198348 municipalities
• 1987Floods and Mudflows · 24 August 198739 municipalities
• 1989Drought (Clay Shrinkage) · 1 June 198937 municipalities
• 1992Floods and Mudflows · 31 May 199236 municipalities

Most Frequently Affected Municipalities

• 27Argenteuil
• 21Montmorency
• 19Sarcelles
• 18Cergy
• 18Deuil-la-Barre
• 18Eaubonne
• 18Enghien-les-Bains
• 18Montigny-lès-Cormeilles

Hazards Listed by Municipality

Number of municipalities exposed to each natural hazard according to the departmental major risks file.

Hazards at a specific address on Géorisques