 Many canals for drainage have been dug in the province of Rovigo because the Po and the Adige are the first and the third biggest rivers of Italy as for rate of flow and the land has a huge amount of water to deal with; the main canals are the "Collettore Padano", the "Ceresolo" and the "Valdentro".Other streams of historic importance are the "Adigetto" (a former course of the Adige), the "Poazzo" (a former course of the Po) and the "Fossa Polesella" (a former waterway connecting the Canal Bianco with the Po).The climate is mild continental with high humidity, having sultry summers and foggy winters; precipitation is normal, usually happens in spring and autumn.