Canale delle Moline (Moline Channel) is the extension of Canale di Reno. Few meters after the walls of Trecento, it joins Torrente Aposa. They both debouch into Canale Navile. Canale delle Moline has been hidden by the surrounding buildings for a long time. Now it is possible to see it through small windows in via Oberdan, via Malcontenti and via Piella. At the end of 1100, the citizens of Bologna built two plumbing systems to provide water to the city. Hydraulic energy supplied mills and other manufactures.