It rises on the rugged western slopes of the
Wolkberg Mountains, part of the Drakensberg Mountain chain, about 20 km SE of
Tzaneen. From its source in this high rainfall zone, the river flows roughly eastward for approximately 140 kilometres before joining the
Olifants River some 7 kilometres to the south of the town of
Phalaborwa. The Ga-Selati River's largest tributaries are the
Ngwabitsi River and the
Mulati River, both joining its right bank. In the dry season, the riverbed of the Ga-Selati is dry for most of its length. This river is heavily polluted owing to mining activity at Phalaborwa in its lower course. ==Dams in the basin==