The Okavango River rises as the Cubango in the Bie Plateau of central Angola and with its major tributary the Cuito, flows southeast. Most rain generally falls in Angola between June and September, and the swollen Cubango rushes southward across the Caprivi Strip of Namibia, spilling over the Popo Falls into northwest Botswana.
Entering Botswana, the Cubango becomes the Okavango River, widening (eventually to about 12 kilometres) and slowing as it enters the flat swampy tract of the panhandle. After passing the Gumare Fault, the Okavango divides into several main channels and many smaller water-courses, slowing to a sluggish speed through the delta.
The delta is a patchwork of swampy areas and islands forested with acacia, palm and fig. Less than half the delta is perennial wetland, but when flooded it covers an area of about 17,000 square kilometers (6,500 sq miles) making it the largest inland delta in the world.
Local rainfall makes up about a third of the delta's water (October to May), the flow rate fluctuating wildly due to rainfall variation, evaporation, and absorption into the riverbed. The dense growth of papyrus reeds is constantly blocking the river channels, continually changing the flow patterns.
Dependant on floodwaters, the base of the delta (to the Kunyere Fault) is sometimes inundated around June and July, yet unless exceptional rainfall occurs, Lake Ngami can remain dry for years at a time.
The Okavango Delta and surrounding areas attracts vast numbers of wildlife, although the Buffalo fences (ostensibly erected to stop disease spreading from wild buffalo to domestic cattle) have proved devastating for migratory animals who find themselves cut off from their traditional grazing routes.
The Tswana (Batswana) people inhabit the area, especially in the panhandle, living by fishing, traditional crafts and some by tourism. The delta's resources seem relativly underutilised due to the profusion of the tsetse fly in the region.