The water level of Lake Garda has dropped significantly within just a few days. At the gauge in Peschiera del Garda , the lake currently measures only +99 centimeters above the hydrometric zero point, a loss of about ten centimeters within a single week. This marks the first time this year that the water level has fallen below the one-meter mark. Twelve months ago, the water level was still 24 centimeters higher.
Responsible for this rapid decline is the persistent heat wave that currently has Italy firmly in its grip and for which the Ministry of Health has issued red heat alerts in 16 major cities. Italy's largest lake is not spared from the extreme temperatures either.
Evaporation, heat, and agricultural withdrawals
Several factors are converging at Lake Garda. For a week, the sun has been shining almost without interruption, with temperatures hovering around 35 degrees Celsius. On particularly hot days, when values exceed 33 or 34 degrees, up to two centimeters of water per day evaporate from the lake's surface. Given the lake's area of roughly 370 square kilometers, that amounts to several billion liters daily.
Adding to this is the agricultural water withdrawal in the Po Valley. At the Salionze dam, where the waters of Lake Garda are diverted into the Mincio River, current outflows stand at 75 cubic meters per second, while only 50 cubic meters per second are flowing in. The basin is approximately 75 percent full. The balance is clearly negative: significantly more water is flowing out than is coming in.
Comunità del Garda calls for reduced outflows
The Comunità del Garda, the association of 55 lakeshore municipalities in Lombardy, Veneto, and Trentino, has responded. Pierlucio Ceresa, Secretary General of the Comunità, has asked the Po River Authority AIPo to reduce outflows from Lake Garda in the coming days as a precautionary measure. "Summer only began three days ago," Ceresa told Radio Bruno Brescia, pointing out that water reserves must not be depleted too early in the season.
Managing Lake Garda is a complex undertaking, as the basin's water serves multiple functions: it is used for drinking water, agriculture, tourism, industry, electricity generation, and even thermal purposes. Daily coordination between AIPo and the Comunità del Garda will be particularly close this season.
Other lakes in northern Italy also affected
Lake Garda is not the only northern Italian lake whose water level is falling sharply. Lake Iseo, located in the Brescia and Bergamo regions, has also lost a considerable amount of water in recent days. Its current level stands at +68 centimeters, compared to +94 centimeters a year ago. Within approximately two weeks, the lake has lost 38 centimeters.
The smaller Lago d'Idro, by contrast, is showing relatively stable conditions, with levels roughly on par with last year. Overall, however, the trend is clear: the most important lakes in northern Italy are suffering under the combination of early heat, high evaporation, and simultaneously high water demand in the Po Valley.
Weather forecast: no quick relief in sight
Short-term relief is not on the horizon. Weather models suggest that heat will actually intensify in the coming days. Temperature increases of two to four degrees Celsius are expected by Monday. In numerous locations around Lake Garda and throughout the Po Valley, highs could climb to as much as 38 degrees.
Meteorologists are already describing this as one of the most severe heat waves in the past hundred years. The occasional convective thunderstorms rolling in from the Alpine region provide temporary reliefbut bring little noticeable cooling. According to current forecasts, no end to the extraordinary heat phase is expected before at least the beginning of July.
No danger to the lake itself
Despite these alarming developments, there is no reason to fear that Lake Garda will actually dry up. The inland lake reaches a depth of 346 meters at its deepest point, with an average water depth of around 135 meters. Even the historic low-water records of 2003 and 2007 produced visibly low water levels along the shores but never threatened the lake's very existence.
What concerns experts more is the underlying trend. Heat phases like the current one were once rare extreme events, but they increasingly appear to be becoming a summer norm. For those interested in reading more about the Italian warning system and the Italian art of coping with extreme temperatures, all the details can be found in our background article on heat in Italy. For travelers, local residents, and farmers alike, this means that questions about water levels in the lakes of northern Italy are likely to arise more frequently and more urgently in the years ahead.
