The Asău is a left tributary of the river Trotuș in Romania.Ovidiu Gabor - , map page 10 Its source is located in the Tarcău Mountains. It discharges into the Trotuș in the village Asău, near Comănești.Asau (jud. Bacau), e-calauza.ro Its length is and its basin size is .
Tributaries
The following rivers are tributaries to the river Asău (from source to mouth):
Left: Asăul Mic, Geamănele Mari, Izvorul Negru, Rugina, Rășcoiu, Păltiniș, Izvorul Alb, Pârâul Tulbure Right: Preotese, Cetățeni, Pârâul Caprei, Pârâul lui Iacob, Agăstin, Barta, Chicera
References