Usora (river)
Great Usora created by merging Gomjenice and Brkića stream. Small Usora springs below (south) of the main road M-4 (Banja Luka – Matuzići, some 10 km west of Pribinić). Before Sastavci locality, right tributary to it are: Mišića rijeka, Great Ostružnja, Inova , Miljkovača, Velika rijeka (Great river), Brezna  and smaller streams, as well as left: Rankovića rijeka, and Gračanica.