It arises from various springs distributed between Casacorba di Vedelago (TV) and Torreselle di Piombino Dese (PD); the Coa Longa fountain, considered the main source, is located in the latter's territory.
It flows with a certain sinuosity from west to east and, once it reaches the capital of the Marche, it bends in a south-east direction towards the lagoon.
It once flowed into Portegrandi di Quarto d'Altino, but in 1663 the Serenissima diverted its course via the Taglio del Sile canal, which transferred its waters to the old bed of the Piave, which in turn was diverted further east (so the last stretch is also called Piave Vecchia). It finally flows into the Adriatic, dividing the Lido di Jesolo from the Cavallino coast (port of Piave Vecchia).
In Portegrandi, however, the old course is still followed by a branch, called Silone, which gives access to the lagoon (nautical traffic is regulated by locks). The Silone proceeds through the marshes and is extended by the Borgognoni canal-Burano canal, which leads to the Treporti canal and, finally, to the lido port.
The entire course is protected by the Sile River Regional Natural Park. As regards the reclamation consortia, its hydrographic basin is divided between the Piave and the Acque Risorgive.