[4] Along its lower reaches, it meanders extensively forming part of the international border between the DRC and the western Ugandan districts of Bundibugyo and Ntoroko, near the Semuliki National Park.

[4] Increasing snow melt from the Rwenzoris, overgrazing, and other alterations to the watershed have caused bank erosion and frequent changes to the course of the meandering lower reaches of the river.

[5] In some places, Uganda is losing up to 10 metres (33 ft) of land per year on its side of the river to erosion and silt from the Semliki is gradually filling in the southern end of Lake Albert.

[6] The Semliki begins near Ishango, DRC, at the northern end of Lake Edward and soon enters Virunga National Park, through which it flows over much of its upper course.

Over its last reach, the river flows west of the international border and enters the southern end of Lake Albert at a point southeast of Bunia, DRC.