ROME - Northern Italian regions risk losing up to half their agricultural output due to a drought, a farm lobby said on Friday, as lakes and rivers across much of Italy start to run dangerously low, jeopardising irrigation.

The federation of Italian utility companies, Utilitalia, warned this week that the country's longest river, the Po, was experiencing its worst drought for 70 years, leaving many sections of the vast, northern waterway completely dried up.

Other rivers stretching into central Italy were also far lower than normal at this time of year, sector authority ANBI said, adding that the current crisis was highlighting "the consequences of climate change on the peninsula".

Agricultural lobby CIA urged immediate action, calling for emergency irrigation to save crops such as tomatoes and watermelons and the creation of new infrastructure, including basins for rainwater storage.

"The total damage (is) already set to exceed one billion euros ($1.05 billion)," CIA said in a statement, adding that water shortages could also hit the production of corn and soya, whose supply is already under threat due to the war in Ukraine.

The governors of the northern Piedmont and Lombardy regions - where part of the agricultural output depends on the Po river - said they would ask the national government to declare a drought state of emergency.

In some areas of Turin, Piedmont's capital, blackouts were reported overnight due to the hot weather stressing underground cables, local media reported.

Unusually high temperatures are being reported across Europe. Spain recorded its hottest pre-summer heatwave for at least 20 years and temperatures around 40 degrees Celsius (104°F) were also reached in France.

(Reporting by Angelo Amante; Editing by Toby Chopra)