• 
  The torrent Edron born on the slopes of Mount Sumbra (m1.764).
  Blocked at 560 meters, form the Vagli's Lake, 3 km long, 200 m wide.
  Affluent of right of the Serchio River in Poggio.
  The water of Lake Vagli is channeled and diverted to the hydroelectric power station of Torrite;
  only the surplus, and sporadically, is left to the Edron River.
• 
  The water that flows into the river Edron, at Isola locatity, as a matter of fact, not from Vagli; but by Careggine, which arises from a multitude of springs.
  Water flows for a stretch on the surface, then it hides underground, and reappears at Ferriera locality then throw himself into the Edron River.
  Before the construction of the dam, the average flow of the river was great and her bed had a size three, four times that today.
  At Ferriera was also a control unit to generate electricity by water of the river.
  It served to fuel the locality Ferriera and Isola.