Because of the low level, salt water has penetrated the riverbed at the mouth of the Adriatic Sea, some 30 kilometres inland.
Italian Prime Minister Mario Draghi on Thursday evening announced measures taken by his government because of the drought.
From Monday on, the government will take care of emergency plans in the affected parts of the country, something that has been demanded by the regions, especially in the north, for weeks.
Draghi also pointed to structural problems: Some of the country's water reservoirs and pipelines are in such a parlous state that 30% of the water is lost.
