The Savinja rises in the north-west versant of the mountain Oistritza, which belongs to the
Kamnik Alps mountain range, near the border
to Austria. The river flows for 96 Km through the Savinja valley and it ends into the Sava River at the town of Zidani Most.
It is a typical alpine stream, with stony bottom and clear cold waters. The water is
categorized as 1st class quality from the spring to the village of Radmirje, that means that
all the reserve falls within the 1st class category.