Supraśl (river)
Supraśl - is a river in east Poland in Podlaskie Voivodeship, a tributary of the Narew river, with a length of 93,8 kilometres and the basin area of 1844,4 km2
Supraśl is the source of the drinking water for Białystok.Tributaries
Słoja, Sokołda, Kamionka, Płoska, Pilnica, Czarna, Biała