A brief description of the geomorphological, historical, and archaeological aspects of the ancient Bononia (now Bologna) supply by means of an ancient tunnel made by Romans at the beginning of the new, era and its evolution to a nowadays when it's already used (13%) to assure drinking water supply of Bologna Town. Recent exploration of the tunnel has permitted to obtain most data of ancient water level signs and size of tunnel section in the different conditions. New data obtained by this exploration allow to build a CAD 3D model of the tunnel and in this way it was possible to calculate the realistic flow of the ancient tunnel. Mathematical model simulations indicate the effectiveness of the ancient tunnel in achieving these objectives in working condition and during the periodical maintenance.
Keywords: ancient tunnel, Bologna water supply, Bononia aqueduct, channel water flow simulation, speleology