Rosanna

The Rosanna is a forty-two-kilometre river in the Austrian Alps that begins high in the Verwall range. It starts in a small lake below the Grieskogel and Fädnerspitze, only a short distance from the Vorarlberg border at nearly 2,600 metres above sea level. From there it flows north through the Ochsental and Schönverwall valleys before reaching the Verwalltal. Near the Konstanzer Hütte it is joined by the Fasultal and Pfluntal streams and widened into the Verwallsee, a reservoir that controls floods and generates hydroelectric power. The Rosanna’s most important tributaries include the Albonabach, Fasulbach and Maroibach, which together shape the river’s flow. Its catchment area covers 275.5 square kilometres, rising to 3,168 metres at the Hohe Riffler. Thirty-one small glaciers cover a total of 4.3 square kilometres, though much of their meltwater is diverted away. At Strengen the river normally carries 9.45 cubic metres per second, peaking in June at 23.3 cubic metres per second and falling to 2.46 cubic metres in February. Visitors can follow the Rosanna’s course through dramatic alpine scenery. In St. Anton am Arlberg the river passes through a narrow gorge before widening into the Stanzer Tal. Below Tobadill it meets the Trisanna to form the Sanna, which flows on to Landeck. The riverbanks remain largely natural above St. Anton, while downstream stretches show occasional to continuous bank reinforcement. The water quality stays very good in the upper reaches and good to moderate further down, making it a clear and lively mountain stream.