 Drinking water, too, was carried from Dolo to the center of Venice by cargo boats with big barrels filled directly from springs of the little river Seriola.The territory was affected by massive hydraulic works that led to the diversion of the main bed of the river Brenta through an artificial canal with new mouths along the southern sea approaches of the port of Chioggia, while just one part of the old Brenta still flows into the lagoon near the location of Fusina.The purpose of these megalithic hydraulic works was primarily to prevent the progressive flooding of the lagoon by the fresh water of the rivers and thus maintaining a high degree of salinity necessary to make possible the navigation and the very existence of Venice.