The Piva river is located between Montenegro and Bosnia and Herzegovina, shorter headwater of the Drina river, which it forms with the Tara river on the border with Bosnia and Herzegovina. The Piva springs from the Sinjac spring on Golija mountain, near the Piva monastery also called Vrelo Pive (Well of Piva). Before the artificial Pivsko Jezero lake was formed, the water from the well rushed into the river Komarnica thus creating the Piva river for the next 34 km.
However, Komarnica is part of a 86 km long river system (Tušina–Bukovica–Bijela–Komarnica), so measured from the source of the Tušina river, the Piva, nicknamed ‘the river with five names’, is 120 km long. The Tušina originates from the mountain Sinjajevina in the Uskoci region of central Montenegro, just few kilometers away from the source of another important Montenegrin river, Morača. The river flows to the west, between the Sinjajevina and Lola mountains, next to the villages of Krnja Jela, Bare, Boan and Tušina.
It receives from the north the Bukovica river, and continues further under this name. After the river passes the regional center of Šavnik and the villages of Gradac and Pridvorica in the region of Drobnjaci, the stream receives from the north the Komarnica and takes its name. The Komarnica continues between the mountains of Vojnik and Treskavac, in an almost uninhabited area and enters the high Piva plateau, where it turns north, almost all of the Komarnica’s course is flooded by the reservoir of the Pivsko Jezero, receives from the right outflow of the Piva spring and enters the deep Piva canyon.