What is Usora (river)?
[[File:Usora ruchunga.jpg|thumb|250px|Usora river]] '''Usora''' is left [[tributary]] of the [[Bosnia (river)|Bosnia]] in central [[Bosnia]]. The total length of the river Usora – from sources below the top of the mountain [[Očauš]] to the mouth above the [[Doboj]] is about 82 kilometers. The town of [[Teslić]], through which it flows, bears the local name Velika Usora (Great Usora), since under the city at a place called Sastavci meets with his same named, but a lot less left tributary Mala Usora (Little Usora). It also comes from the mountain masiff [[Uzlomac]] – [[Borja]] – [[Očauš]] below it in smaller distances rises more Bosnia river and their tributaries, as well as the basin [[Vrbanja river]] and [[Ukrina (river)|Ukrina]]. In its upper reaches, the river makes a wide loop around Borja, from its southwest to northeast slopes.<ref>{{cite web|url=http://www.kartabih.com/|title=Karta BiH - Karta Bosne i Hercegovine|publisher=}}</ref><ref>Vojnogeografski institut, Izd. (1955): Teslić (List karte 1:50.000, Izohipse na 20 m). Vojnogeografski institut, Beograd.</ref><ref>Spahić M. et al. (2000): Bosna i Hercegovina (1:250.000). Izdavačko preduzeće „Sejtarija“, Sarajevo.</ref><ref>Mučibabić B., Ur. (1998): Geografski atlas Bosne i Hercegovine. Geodetski zavod BiH, Sarajevo, {{ISBN|9958-766-00-0}}.</ref> 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&nbsp;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. In much of the flow Ukrina is flooding river but the increasingly frequent flooding causes significant damages. In the early Bosnian history Usora belonged to gold-bearing river, and it is believed that this is still in its upper course along with the many large and small tributaries and streams. Obvious hydro-energ