ANBI Observatory: Heatwave Returns: Red Alert in Water-Crisis Areas

The favorable effects of the Azores anticyclone on Western Europe are gradually diminishing. After the Iberian Peninsula recorded temperatures above 40°C, warm air masses from the Sahara are now reaching Italy, causing a renewed increase in temperatures in many areas, well above seasonal averages.

June proved to be the hottest on record in several European countries, including Italy, with average temperatures 3°C above normal. The ensuing break from the scorching heat improved urban livability and favored a temporary cooling of the Mediterranean sea, which had previously deviated from its usual values, with anomalies exceeding 5°C in some areas.

Despite this, critical water situations remain in large areas of central Italy (with the exception of Tuscany), southern Italy, and the islands. In many of these areas, where water problems were already well-established, the situation has further worsened. This is accompanied by an increase in extreme weather events : in July alone, 318 events were reported, including tornadoes, heavy rainfall, and significant hailstorms, according to the European Severe Weather Database . The ANBI Observatory on Water Resources provides the update.

“ The data confirm that current rainfall patterns, a consequence of the climate crisis, have a greater impact on hydrogeological risk than on water availability ,” commented Francesco Vincenzi , President of ANBI (National Association of Consortia for the Management and Protection of Land and Irrigation Water).

Massimo Gargano , Director General of ANBI , adds: " Hence the need to urgently equip the territory with new hydraulic infrastructure, including multifunctional basins capable of retaining rainwater, creating reserves and safeguarding the territory from disasters. We are working in this direction with works and projects, but a national land maintenance plan with multi-year and reliable funding is needed ."

According to data from the Central Apennines District Basin Authority , the current hydrological year has been poor in rainfall, with rainfall totals dropping by 19% in Lazio and 14.6% in Umbria. The most worrying situation, however, continues to affect Southern Italy, where prolonged drought and the return of the African anticyclone raise fears of even more critical scenarios than those experienced in the past two years. In Campania , for example, the Cassano Irpino springs have shown a reduction in flow of 1,100 liters per second, while the Sanità spring has a deficit of 750 liters per second , according to data from the Southern Apennines District Basin Authority.

In Calabria , severe water shortages have been formally recognized in the provinces of Reggio Calabria and Crotone. In Puglia, some rainfall stations located in Salento—particularly in the northern area—did not record significant rainfall in June and July, with values hovering around zero or, at most, 2 mm. The Capitanata reservoirs contain only 67.45 million cubic meters , 1.11 million less than last year. Furthermore, forecasts indicate the province of Foggia as one of the areas most exposed to rising temperatures in the coming days.

In Sardinia , tourism has increased water consumption, contributing to a reduction of 134.39 million cubic meters in the island's basins in July alone. On the western side, the Nurra area has just 12% of the authorized water reserves (13 million out of a potential 109 million cubic meters), while in the Alto Cixerri area, availability has dropped to even below 11% (2 million out of 19).

Basilicata has seen a 14.4% drop in water reserves compared to the same period last year, equivalent to a reduction of over 31 million cubic meters . Further north, in Abruzzo, the Penne Dam has a reservoir level of 3.49 million cubic meters : higher than last year but still 11% lower than the average of the last eight years.

In Lazio , the "Castellani" lakes continue to decline: in just one week, the water level of Lake Nemi has dropped by another 6 cm, while that of Lake Albano has lost 4 cm. The Tiber and Aniene rivers are showing decreasing flows , while in Sabina the Velino River has returned to normal values. In Umbria, Lake Trasimeno has recovered 3 cm in a week but remains far from both the average values (-77 cm) and the critical threshold. The Maroggia reservoir currently contains 2.55 million cubic meters , and the Topino River is showing rising levels.

July's rainfall brought temporary relief along the northern coast of the Marche region , but overall, the region's rivers—particularly Potenza, Esino, and Sentino—are experiencing a decline in flow. The Marche region's reservoirs remain well-stocked, with over 47 million cubic meters , a figure that, apart from 2023, is among the highest in recent years.

Tuscany , bucking the trend of other regions in Central Italy, has benefited from a particularly favorable hydrological year, with above-average rainfall. This has led to a significant increase in the Arno River's flow, now well above the average of the last twenty years. In Liguria , however, an increase in water levels has been observed in the eastern basins.

Northern Italy , in general, benefited from abundant water availability, although there were differences between the various basins and, in some Alpine areas, deficits in accumulated snow. Veneto, for example, received rainfall in July alone that was 52% above the regional average , with notable peaks in the basins: +143% on the Livenza, +96% between the Livenza and Piave, +79% on the Sile, +73% on the Piave. The Adige, Bacchiglione, and especially the Brenta rivers (with a flow rate 76% above average) also showed positive signs. However, with the exception of Lake Garda, the large lakes of the North are showing decreasing levels: Lake Maggiore is 57.1% full, Lake Lario is 39.4% full, Lake Benaco is 75% full, and Lake Sebino is 83.6%.

In Lombardy , recent rainfall has brought water reserves back to average values for the period. In Piedmont, however, a reduction in flows has been observed in the Tanaro, Stura di Lanzo, Stura di Demonte, and Toce rivers. In the Aosta Valley, the water level of the Dora Baltea is below average and decreasing, while that of the Lys stream remains stable. The Po River shows a reduction in flow between its sources and Boretto (in Emilia), while in the section from Borgoforte to the Delta, flows have increased, returning to typical values for the period.

In Emilia-Romagna , the situation is diverse: the Savio, although decreasing, remains above average, while the flows of the Reno and Secchia are decreasing—with the Reno reaching historic lows. Flows of the Lamone and Santerno rivers in Romagna, however, are increasing. Finally, the Mignano and Molato dams in Piacenza are holding just over 3 million cubic meters of water , a 75% deficit compared to the same period in 2024.