Most of the country's many rivers originate in central Angola, but their patterns of flow are diverse and their ultimate outlets varied. A number of rivers flow in a more or less westerly course to the Atlantic Ocean, providing water for irrigation in the dry coastal strip and the potential for hydroelectric power, only some of which had been realized by 1988. Two of Angola's most important rivers, the Cuanza and the Cunene, take a more indirect route to the Atlantic, the Cuanza flowing north and the Cunene flowing south before turning west. The Cuanza is the only river wholly within Angola that is navigable--for nearly 200 kilometers from its mouth- -by boats of commercially or militarily significant size. The Congo River, whose mouth and western end form a small portion of Angola's northern border with Zaire, is also navigable.

North of the Lunda Divide a number of important tributaries of the Congo River flow north to join it, draining Angola's northeast quadrant. South of the divide some rivers flow into the Zambezi River and thence to the Indian Ocean, others to the Okavango River (as the Cubango River is called along the border with Namibia and in Botswana) and thence to the Okavango Swamp in Botswana. The tributaries of the Cubango River and several of the southern rivers flowing to the Atlantic are seasonal, completely dry much of the year.