Its source is at the foot of the hill of Stol, above the village of Breginj, and it covers the distance of 4.7 km before entering the Nadiža at the village of Podbela. Its bed was almost completely regulated in the 1930s – it was split up by numerous barriers. Deep pools formed below these barriers, while above them, gravel banks appeared.
The first kilometre of the Bela is breeding water, while the rest is open for fishing. The river is inhabited by all species of trout, numerous Cottus gobio and Austropotamobius italicus. In its lower stretches, one can find grayling and some Alburnus a. alborell as well.