Quels usagers derrière les consommations d’eau potable du bassin Seine-Normandie ?

In April 2023, French President Macron presented the action plan for resilient and concerted water management. One of its objectives is to achieve a 10% water abstraction reduction in France between 2019 and 2030. On the Seine-Normandie water basin, in order to reach that objective, the basin committee passed a specific goal per type of use, including a 14% potable water abstraction reduction. This goal cannot be reached solely by repairing drinking water networks. Direct actions are therefore necessary towards the final users of potable water (households, administrations, firms…). Nonetheless, no national database exists that provides how much each of them uses. Client databases are owned by numerous local operators with unequal levels of knowledge and various classifications. This lack of information can prevent efficient action planification to reduce water abstraction. A hybrid statistical-qualitative conjoined approach is developed to create a database with potable water abstraction per type of user at the municipality level in 2022. Although in some cases unreliable at the level of each municipality, the results can be used at the scale of associations of municipalities and serve as a tool in sufficiency planification workshops. Overall, in the basin, 71-75% of potable water goes to households, 10-11% to retail and services, 10% to public services, 2-4% to manufacturing and extractive industries, 1% to agriculture, and less than 1% to tourism surplus. The mean water consumption per inhabitant can also be deduced. It is equal to 41 m3/pers/year, below the national mean (50 m3/pers/year). This result can be explained because of the high rate of apartments and the northern climate compared to the national average. The method can be replicated in other French territories, and the detailed methodological report is available online on the Seine-Normandy water agency website.