Lago della Vacca, Artificial reservoir in Caffaro Valley, Province of Brescia, Italy.

Lago della Vacca is an artificial reservoir in the upper Caffaro valley, Province of Brescia, at 2358 m below the west wall of Cornone di Blumone. It fills a glacial basin at the southern end of the Adamello range, with a surface of 25.6 ha and an average volume of 2.4 million cubic metres. Its concrete gravity dam, 17.5 m high and 87 m long at the crest, holds back the water.

The dam at Lago della Vacca is a concrete gravity structure with a volume of 5,600 m³, a maximum height of 17.5 m and an 87 m crest. It was completed in 1927, a few years after the Gleno disaster had raised doubts about the reliability of dam-building techniques of the time. The reservoir feeds the Gaver hydroelectric plant, first run by the Caffaro concessionary company and now by Edison S.p.A.

The reservoir takes its name from the nearby Passo della Vacca, where rock formations create a silhouette resembling a large cow. This naming reflects how mountain communities observe and interpret the landscape around them.

This location is accessible only via mountain trails and is best visited during summer months when snow does not block the routes. Getting there requires good physical fitness and proper equipment suited for high-altitude hiking.

The dam holds 5,600 cubic metres of concrete, stands 17.5 metres high and runs 87 metres along its crest. It was finished in 1927, a few years after the Gleno disaster raised doubts about the reliability of dam-building techniques of the time.