Adige River Flood Control Tunnel: History of Water Diversions

It was designed because it was considered the most effective system for managing the floods of the Adige. Ten kilometers of tunnel (specifically 9,873 meters) to divert the river’s waters directly into Garda Lake. Excavation began on March 1, 1939. It was completed in 1959. Just a few months later, at 11:30 AM on September 17, 1960, the first opening took place. Subsequently, nine more openings occurred along the tunnel. Few, all in all, and fortunately. In any case, the first time the Adige-Garda diverted into the lake, taking advantage of its maximum capacity, was 71,325,000 cubic meters of muddy waters. It would take another five years for the second time: May 2, 1965. On this occasion, an even larger volume of 79,270,000 cubic meters was discharged—the biggest outflow. The following year, in the middle of summer, on July 22, another brief opening occurred, releasing 6,499,920 cubic meters. That was a rainy year, 1966. The fourth opening happened on August 7 of the following year, with 16,695,000 cubic meters. And the fifth on November 4, with as much as 63,777,300 cubic meters. Only ten years later, on September 13, 1976, another occurred, with 37,260,000 cubic meters. On October 17, 1980, another, with 18,100,000 cubic meters. Again, on July 18, 1981, with 6,930,000 cubic meters. The penultimate time was on May 23, 1983, with 20,160,000 cubic meters. The most recent event, twenty-one years later, in November 2000, involved minimal flow (100 cubic meters per second), with only about 5 to 6 million cubic meters of water released.