Seven years after the start of the construction works at Vieux Emosson, the reservoir has reached full capacity for the first time to supply water for the generation of electricity in the future. While the reservoir was being filled – the process having begun in the spring of 2017 – surveillance of the dam was reinforced. In addition to daily telemetry readings and weekly monitoring measures (with pendulums, rock meters etc.), further steps were initiated. Additional research was carried out at each stage, involving geodesic measurements, a detailed site inspection, opening of the outlet gates, and inspections by experts and the Swiss Federal Office of Energy. The reservoir priming programme is continuing with the first draining, which is due to start in spring 2020. During this phase, Vieux Emosson will again be subject to extra monitoring.