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.
Sharing the water of the Ganges arrangement and recognised Bangladesh's rights as a lower-level riparian. Descending from India's northern plains, the Ganges river forms a boundary of 129 kilometres between India and Bangladesh and flows for 113 km in Bangladesh. At Pakaur in India, the river begins its attrition with the branching away of its first distributary, the Bhagirathi River, which goes on to form the Hooghly River. About 10 kilometres from the border with Bangladesh the Farakka Barrage, built in 1974, controls the flow of the Ganges, diverting some of the water into a feeder canal linking the Hooghly to keep it relatively silt-free. After