During the evening, cyanobacteria pollution was detected in the safe drinking water network shared by 2 towns. These microscopic algae that are capable of producing toxins had developed due to the hot and sunny weather over the preceding few weeks. The town hall and Compagnie Fermière distributed bottles of water to the inhabitants: over 16,000 1.5 l bottles were ordered from a bottled water company. The Prefecture informed the population of the situation by local radio. The Prefecture banned the washing of teeth, drinking from the tap and using it for cooking. It also recommended reducing the time spent in the shower or bath, monitoring children to make sure that they did not swallow any water and not to fill swimming pools including paddling pools. On 11/08, 2 supply road tankers (2 x 25 m³) performed rotations to replenish the water in the network that had been drained. A mobile water filtering system, with a treatment capacity of 5 m³/h, was installed to complete the water make-up in the network. Analyses were carried out on the raw water and treated water. At the same time, epidemiological monitoring was established in close collaboration with the 4 doctors in Coquille and the emergency services of the hospitals in Périgueux and Limoges. The ban taken concerning the consumption of water for food and sanitary purposes was kept in place until the analysis results had been obtained. On 14/08, a further distribution of safe drinking water was set up. The analysis results showed steady reduction of the concentration of cyanobacteria following the drainage carried out. The water usage restriction was kept in place and new samples were taken. In order to protect the municipal supply system’s water resource, a municipal order banned the use of the water for sprinkling that was not absolutely essential for public health and safety, the filling of private swimming pools and the washing of vehicles with the exception of regulatory obligations and excluding professional facilities equipped with water savers. On 16/08, significant reduction in the concentration of cyanobacteria in the supply water led to relaxing of the ban: the water could then be used for cooking and sanitary requirements, however the ban on drinking tap water remained in place. On 18/08, the situation was back to normal.