This research is presented in three sections. The first is an historic study about 'cura Tiberis, that sets out to clarify the relationship between magistrature and the floods of the Tiber River, with particular attention to the river's delimitation, and the juridicial powers of the 'curatores'. Included is a study of official subordinates. The second section consists of investigations into the 'senatores' who held the 'cura Tiberis' from its foundation until the 4th century AD. The last section gathers and comments on related inscriptions.