It is enough a gap of few meters to stop the flow of the fish in a river. Many human interventions have fragmented the watercourses with hydropower barriers and weirs in order to slow down the down flow of the water. The construction of bridges, like the Migiandone (Ornavasso) one, can create interruptions too, damaging fish populations. The project IdroLIFE intervenes to defragment five artificial barriers on the River Toce and Stream San Bernardino course, to restore the connectivity of a 45 km segment, from Lake Maggiore to the first natural obstacle. Picture by Marco Tessaro – comunicazione ambientale