Lake Garda Flooding: Complex Causes and Interconnected Water Systems

If Lake Garda has reached critical levels that it still struggles to drain, and if it continued to swell up to one meter and 74 centimeters above the zero hydrometric level, even with the Salionze barrage releasing a maximum flow of 190 cubic meters of water per second into the Mincio, this must be attributed to a complex set of causes, some related to the exceptional climatic conditions that occurred in November, and others to the delicate web of balances and responsibilities involved in managing one of the most complicated water systems in Europe.

Interconnections of the Water Systems

The fate of Lake Garda, in fact, is interconnected with that of the Adige and Po rivers, Italy’s two main rivers, with the three Lakes of Mantua, whose regulation is the most complex in Europe, and also with the Fissero Tartaro waterway, the most important navigable stretch on the Italian Peninsula. Upstream, the lake also receives water from the Sarca and its tributaries, as well as from 11 hydroelectric plants connected to this tributary, the most significant of which is Lake Molveno, which alone regulates a reservoir of approximately 150 million cubic meters of water.

The Mori Torbole spillway, which allows the Adige to discharge into the lake, is in turn the largest drainage tunnel in Italy. Furthermore, ground water infiltrations, with unknown and generally marginal flows, also influence the lake’s flood levels.