Abstract
Perceived both as competing with water policing missions and as not essential to the State’s activity, public engineering missions were abolished in 2008. Based on the impact analysis of this reform, this paper discusses the evolution of the capacity of the State’s territorial administration to act to protect water and aquatic ecosystems. The results of a field survey conducted in three French departments between 2014 and 2019 show us that this State reform leads the territorial administration to confirm its regalian posture and, therefore, to harden the formal application of water regulations. However, this evolution is taking place in parallel with the institutionalisation of a “degraded mode” of administration at the expense of the aims of environmental public action and the social acceptance of environmental law.