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 the situation of overfishing in the upper Zambezi and its tributaries was considered dire, in part due to weak enforcement of the respective fisheries acts and regulations. The fish stocks of Lake Liambezi in the eastern Caprivi were found to be totally depleted, and surveys indicated a decline in the whole Zambezi-Kwando-Chobe river system. Illegal fishing (i.a. by foreign nationals employed by Namibians) and commercially minded individuals, exploited the resources to the detriment of local markets and the communities whose culture and economy depend on these resources. Namibian officials have consequently banned monofilament nets, and imposed a closing period of