What is "cosia"

The Cosia is a 16 km Italian torrent whose springs are on the slopes of Monte Bolletone (1317 metres) in Brianza. After a course of some 16 km, which takes it through the communes of Albese con Cassano, Tavernerio and Como, it enters Lake Como near the war memorial executed by Giuseppe Terragni to a design by Antonio Sant'Elia. The river has two tributaries: the Valloni on the left and the Tisone on the right.

The few fish which the river supports are mostly souffia, members of the carp family.

On 14 October 1607 the Cosia caused disastrous floods at Como which the historian Primo Tatti described in his life of Saint Giovanni da Meda: the monasteries of Santa Chiara and Santa Margherita were destroyed, as was the Collegio Gallio, together with its church which held the remains of the saint, and the church of Rondinetto which was rebuilt on a new site.

Another flood struck Tavernerio on 8 November 1951, causing immense damage to property, and claiming a number of human victims.