Seine-Saint-Denis

Recorded Natural Hazards (Géorisques)

It has 39 municipalities and 1,704,316 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 511 times since 1982 (one declaration per municipality and decree), mostly for floods (303) and drought (158). The most recent was signed on 22 September 2024. 33 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 199940 municipalities
• 1999Floods and Mudflows · 25 December 199940 municipalities
• 1983Floods and Mudflows · 24 June 198323 municipalities
• 1990Floods and Mudflows · 26 June 199023 municipalities
• 1995Floods and Mudflows · 23 August 199519 municipalities
• 2020Drought (Clay Shrinkage) · 1 July 202018 municipalities

Most Frequently Affected Municipalities

• 23Livry-Gargan
• 22Villepinte
• 21Noisy-le-Grand
• 21Tremblay-en-France
• 20Gagny
• 19Neuilly-Plaisance
• 18Rosny-sous-Bois
• 17Montreuil

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