The water flow in the Zambezi river is estimated at 3 600 cu m per second. This represents about 87 mm/year of equivalent rainfall and less than 10 per cent of the average rainfall in the basin (Shela 2000). The average annual rainfall in the basin is about 950 mm/year (Mitchell 2004), but is unevenly distributed across the basin. The southern and western parts of the basin receive less rainfall than the northern and eastern parts. The more densely populated areas are located in the medium to low rainfall areas (Shela 2000). Water consumption in the Zambezi basin is estimated at 15–20 per cent of total runoff (SADC and SARDC 2008). The consumptive uses include water supplies for drinking and sanitation in the basin’s cities and towns, including Blantyre, Bulawayo, Harare, Kitwe, Lilongwe, Lusaka, Ndola and Tete. Irrigation consumes about 1.5 cu km per year. About 200 000 hectares of the estimated potential 7 million hectares have been developed for irrigation in the basin (Shela 2000).
From collection: Zambezi River Basin - Atlas of the changing Environment