Italy's longest river runs dry as heatwave threatens Parmesan production

Seawater is seeping into Italy's longest river as the Po begins to run dry in the grip of an unprecedented heatwave, according to reporting from The Local Italy on Saturday. The intrusion marks a critical threshold for the farming heartland of the northern plain, where the river supplies irrigation and drinking water to dairy herds that produce milk for Parmesan cheese, one of Italy's most valuable agricultural exports.

The Po basin stretches across Piemonte, Lombardy and Emilia-Romagna, regions that together account for the bulk of Italy's dairy output. As temperatures soar above 40 degrees Celsius across the north, demand for irrigation water has surged while the river's flow has collapsed, forcing farmers to choose between depleting groundwater reserves or abandoning fields. Reuters reported on Friday that scientists have attributed the record-breaking heatwave to human-caused climate change, with the intensity of the weather system now described as "unequivocally" linked to emissions.

The Po's drying comes as Italy faces what researchers warn is likely the longest heatwave on record. The Local Italy reported Thursday that five people died from heat-related causes on Wednesday alone, and red heat alerts had been issued for 17 Italian cities. The Guardian reported Saturday that temperatures across Germany and Italy had broken June records, with the weather system moving eastward across Europe and expected to claim more lives.

For Piemonte's agricultural sector, the crisis extends beyond Parmesan production. The region's wine industry, built on Barolo and Barbaresco grapes that depend on precise irrigation timing, faces similar pressure. Farmers across the Po plain are now rationing water and preparing for potential crop losses. The economic toll is already evident: experts quoted by The Local Italy on Friday warned that the heatwave's impact on productivity and growth would be significant across European economies, with power demand straining grids and supply chains disrupted.

The intrusion of seawater into the Po signals a shift in the river's hydrology that threatens long-term agricultural viability in the region. Groundwater depletion, once a distant concern, has become an immediate crisis. Piemonte's farming cooperatives and dairy producers now face decisions about rationing and potential yield reductions that could ripple through European food supply chains. The wire does not yet report specific production forecasts or damage estimates, but the trajectory is clear: the heatwave has moved from a weather story to an agricultural emergency.