The Po River flow has dropped dramatically in northern Italy, allowing seawater to travel far upstream into the delta region around Porto Tolle.
This environmental shift threatens the delicate balance of the Po Delta, as saltwater intrusion can contaminate freshwater sources used for agriculture and local ecosystems. The phenomenon occurs when the outward pressure of the river is too weak to repel the sea.
Reports from June 2026 indicate that the river flow more than halved in just 10 days [4]. This collapse in volume is attributed to a severe drought and an African heat wave that has gripped the region [4].
The impact is most visible in the Po Delta, where water levels have fallen three meters below the normal flow level [1]. Because of this deficit, seawater has risen up the Po for approximately 20 kilometers [2]. This represents a rapid escalation of the crisis, as the seawater had risen about 10 kilometers only a week earlier [2].
Local observations in Porto Tolle show a landscape unusually dry for the region. The combination of high temperatures and low precipitation has reduced the river's discharge to critical levels, creating a vacuum that the Adriatic Sea is filling.
The salinity wedge, or the "cuneo salino," continues to move inland as long as the discharge remains low. This process risks altering the soil chemistry of the surrounding farmlands, and disrupting the natural habitat of the delta's diverse wildlife.
“Seawater has risen up the Po for about 20 kilometers”
The rapid inland movement of seawater indicates a systemic failure of the river's natural hydraulic barrier. When the Po's discharge drops this significantly, the resulting salinity intrusion can cause long-term soil degradation and render freshwater irrigation systems unusable, potentially leading to agricultural losses in one of Italy's most productive regions.
