More than 100 municipalities in Italy's northern regions of Piedmont and Lombardy are already facing water supply difficulties, the Po River Authority (ADBPO) said.Some are using tanker trucks to fill drinking water reservoirs, it added.At the foot of the Alps, Lake Maggiore and Lake Como saw their water levels drop in a week by seven percent and six percent respectively, according to the ADBPO, after water from the lake was used to help irrigate fields throughout the dried-up valley with water stored during the winter. As in much of Europe, summer arrived too early in Italy's northern regions -- including in northwestern Veneto, which is also facing shortages. After a dry spring, the months of June and July have seen record heat that has melted snow reserves.Twenty river basins in Italy's north, where a new heatwave is expected to arrive on Friday, have already been granted permission to bypass minimum water flows in rivers to avoid a destructive farmland drought like that of 2022.Around Turin and even in the centre of the Piedmontese capital, the Po has become covered with aquatic plants and algae, stimulated by the heatwave, an AFP photographer said.In the rice fields between Turin and Milan, "the intense heat of recent days, on top of the severe water stress affecting the rice-growing area, risks compromising the entire season's production", farming union Confagricoltura said.Despite a short spell of recent rainfall, the north has less water in lakes and rivers than it did 10 days ago, when the authority last met, said ABDPO Secretary General Alessandro Delpiano."Let's not fool ourselves into thinking that summer storms can solve deep-rooted problems," he added. The heatwave that parched Europe in June would have been almost impossible without climate change, according to climatologists from the World Weather Attribution group (WWA).