Overview

• The HYDROS 25 exercise runs October 13–17 with mobile alerts targeting selected areas in Seine-et-Marne, Essonne, Seine-Saint-Denis, Val-de-Marne and Paris.
• Scheduled tests include La Ferté-Gaucher on October 13 (10:30–12:30) and, on October 15, Essonne (10:00–11:00), Seine-Saint-Denis (11:30–12:00), Val-de-Marne (11:30–12:00) and Paris’ Beaugrenelle neighborhood (13:00–13:30).
• Phones in the test zones will emit a loud notification that identifies the message as a drill, requires no action, advises against contacting emergency services and cautions against sharing false information.
• Recipients can complete a feedback questionnaire, while more than 100 partners—including local authorities and operators such as RATP and Enedis—test alert chains and protections for critical infrastructure.
• Paris is staging a live evacuation of 109 quai de l’Hôtel de Ville with volunteers as the scenario models a centennial Seine flood that could affect hundreds of thousands of residents and disrupt power, heat, water and transport.