Hydrography thumb|Braies Lake or Pragser Wildsee|301x301px The most important river in South Tyrol is the Adige, which rises at the Reschen Pass, flows for a distance of about to the border at the Salurner Klause, and then flows into the Po Valley and the Adriatic Sea. The Adige, whose total length of in Italy is exceeded only by the Po, drains 97% of the territory's surface area. Its river system also includes the Eisack, about long, and the Rienz, about long, the next two largest rivers in South Tyrol. They are fed by numerous rivers and streams in the tributary valleys. The most important tributaries are the Plima, the Passer, the Falschauer, the Talfer, the Ahr and the Gader. The remaining 3% of the area is drained by the Drava and Inn river systems to the Black Sea and by the Piave river system to the Adriatic Sea, respectively.
hydrography thumb|braies lake or pragser wildsee|301x301px the most important river in south tyrol is the adige which rises at the reschen pass flows for a distance of about to the border at the salurner klause and then flows into the po valley and the adriatic sea the adige whose total length of in italy is exceeded only by the po drains 97% of the territory's surface area its river system also includes the eisack about long and the rienz about long the next two largest rivers in south tyrol they are fed by numerous rivers and streams in the tributary valleys the most important tributaries are the plima the passer the falschauer the talfer the ahr and the gader the remaining 3% of the area is drained by the drava and inn river systems to the black sea and by the piave river system to the adriatic sea respectively