The Rio Ostera

To mitigate the river’s force and regulate its flow in the event of flooding, following the events of ’66, the State Forest Service carried out major hydraulic and forestry improvement works, which are still visible today and are concentrated primarily in the lower part of the valley, from the Grotto of Our Lady of Lourdes to the point where the stream flows into Lake Santa Caterina:

• Along the dirt road upstream from the Madonna di Lourdes grotto, there is a concrete wall to prevent erosion of the bank where the forest road runs;
• The entire stretch from the Madonna di Lourdes Grotto to where the stream flows into the lake near the Hotel Juventus is dotted with weirs, built to reduce the gradient of the stream bed. These are concrete steps that artificially create cascades to reduce the stream’s kinetic energy during high-water conditions.

At the point where we are, however, given the distance from the town and the presence of riparian vegetation, the stream has not undergone any hydraulic-forestry improvements and retains its natural form, reflecting the valley’s original appearance.