OVERVIEW OF THE IMPACT OF MINING ON THE ... - IIED pubs

3.34.1 General description
3.34.1.1 Hydrology
This is Zones H1-H5 of Area C (ZSG, 1984). The long Manyame Sub-catchment stretches from Lake Cahora
Bassa to the capital city of Harare and to Waddilove Mission in Mashonaland East (Figure 3.2). The Manyame
River is perennial. The Manyame is dammed at Chivero (Hunyani Poort / McIlwaine) and Manyame Dam
(Robertson) to provide water for the City of Harare, and at Seke (Prince Edward) and Harava (Henry Hallam) to
provide water for the City of Chitungwiza.
3.34.1.2 Geology
See Figure 3.6 (ZGS, 1999). The sub-catchment lies mainly on the Zimbabwe Craton, underlain by granites in
the central and southern areas, with the Harare Greenstone Belt in the southeast and the Chinhoyi Greenstone
Belt in the west. The Great Dyke crosses the sub-catchment NNE to SSW. The Zambezi Valley in the north is
underlain by Dande Formation sediments (in contrast to ZGS (1999)).
3.34.1.3 Pedology, agriculture and land use
Soils in the sub-catchment can be divided into four groups:
• Very shallow, gravelly soils in the hills along the Zambezi Escarpment, the Manyame Range and the Mvurwi
Range;
• Moderately shallow, coarse grained sandy, kaolinitic soils derived from granites;
• Deep kaolinitic clays, formed from the Greenstone Belt rocks;
• Moderately shallow to moderately deep sands, sodic in places, formed from Dande sediments (DRSS,
1979).
The sub-catchment lies generally within Natural Region IIa: high and reliable rainfall of up to 1000mm per
annum and deep soils; the Zambezi valley is in Region IV: fairly low rainfall of 450mm to 650mm per annum
(ZSG, 1997; Surveyor General and AGRITEX, 1998).
Land use is mainly commercial farming, private and resettlement land with Communal Lands in the Zambezi
valley (ZSG, 1998). Farming is generally intensive livestock and cash crop production, except in the Zambezi
valley where poor soils and low rainfall limit agriculture to some livestock, cotton and a few drought resistant
crops.
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