Luangwa River ago, there was no way out and the Luangwa Rift filled with a Rift Valley Lake called the Madumabisa Lake, which rivalled Lake Malawi in size. The water of the lake overflowed in a river to the south-west, towards what is now the Kalahari, where it combined with the Okavango, Upper Zambezi, Cuando and Kafue rivers, emptying into the Limpopo River and flowing to the Indian Ocean. Several geological events combined to produce the current river systems. Faulting produced another graben just to the south of the Luangwa Rift, and running east-west: the Zambezi Rift Valley and the Chicoa Trough.
Zambezi 1,378,000 km, 3424 m/s, measured at Marromeu Total Zambezi river basin: 1,390,000 km, 3424 m/s discharged into delta "Source: Beilfuss & Dos Santos (2001)" The Okavango Basin is not included in the figures because it only occasionally overflows to any extent into the Zambezi. Due to the rainfall distribution, northern tributaries contribute much more water than southern ones, for example: the Northern Highlands catchment of the upper Zambezi contributes 25%, Kafue 8%, Luangwa and Shire Rivers 16% each, total 65% of Zambezi discharge. The large Cuando basin in the south-west on the other hand contributes only about 2 m/s because