The river flows out of the three streams in the Jizera Mountains: Bílá Smědá, Černá Smědá, and Hnědá Smědá, in the Czech Republic. The main of those is considered Bílá Smědá emerging from the peat bogs between Smědavská and Jizera mountains. From the village of Ostróżno to the mouth of the stream Boreczek it is a border river, flows through Niedów Lake (Witka Lake), and escapes to the Neisse River next to the palace in the village Radomierzyce.