After having already studied natural-risk prevention and tunnel security for the Parliamentary Office for the Evaluation of Scientific and Technological Choices (OPECST), Christian Kert will consider this new subject concerning the prevention of risks that are at once natural and industrial, for dam and hydraulic-structure safety, which are as much dependent upon climatic vagaries as the quality of construction. While the monitoring of large dams has been strengthened in France, especially since the publication of what could be considered as alarming inspection results, the many smaller dams, often privately owned, remain a source of some concern. Recent regulations should solve certain problems, but the results of these new measures will not be known for a few years, as time is needed to optimize the surveillance teams. The other hydraulic structures are perhaps a greater cause of concern, especially dykes which - contrary to dams, whose initial activation or "flooding" represents their critical point - must deal with abrupt climatic changes. Indeed, dykes, designed to protect against the risk of future floods, are generally dry (and therefore unstressed). How can we ensure their effective surveillance, as well as an effective and continual warning system? This study seeks to assess the situation, examine the available technical solutions, and evaluate the administrative risk surveillance and management system, while taking into account the particularities of each body of water. After having gathered information on the state of several French sites and identified those elements requiring improvement, the rapporteur plans on visiting similar installations abroad in search of possible solutions.