The name is derived from the Czech word ostrá (literally 'sharp', but here figuratively meaning 'fast flowing').

In a broader point of view, the Ostravice (as Bílá Ostravice) originates in the territory of Bílá on the border between the Hostýn-Vsetín Mountains and Moravian-Silesian Beskids at an elevation of 751 m (2,464 ft) and flows to Ostrava, where it enters the Oder River at an elevation of 199 m (653 ft).

[3] The sources and longest tributaries of the Ostravice are:[4] The largest settlement on the river is the city of Ostrava.

It was built in 1964–1969 and its primary purpose is to supply Ostrava and its surroundings with drinking water and protect the area behind the reservoir against floods.

It was first agreed as such in 1261 by a special treaty between Duke Władysław Opolski and King Ottokar II.

[7] It lost importance as a state border in 1327, when the Duchy of Teschen became a fee of the Kingdom of Bohemia.

[6] The Ostravice is suitable for river tourism only when water is released from Šance Reservoir, which is once or twice a year.