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

None available.
4.10.6 Implications for water quality and quantity management
Available evidence does not suggest any high impacts of mining on the Mwenezi Sub-catchment. Such impacts
as occur will relate to the extensive chrome and emerald workings in the south of Mberengwa District.
4.11 The Mkgadikgadi catchment
4.11.1 General description
4.11.1.1 Hydrology
This is Zones K, T and N of Area A (ZSG, 1984). The Nata (Manzamnyama) River, and its main tributaries, the
Tegwani and the Maitengwe, flows from the Bulawayo – Plumtree area northwestwards into the Kalahari Desert,
where they ultimately flow into the Mkgadikgadi Pans. The Gwabazabuya or Dzivanini River, which flows
occasionally from the area west of Tsholotsho, joins the Nata in Botswana. Although the Mkgadikgadi Pans
normally form a closed drainage system, during very infrequent times of flood, they overflow into the headwaters
of the Motloutse River, a tributary of the Limpopo. For this reason, the Mkgadikgadi Catchment is discussed
under the Limpopo Catchment.
4.11.1.2 Geology
See Figure 3.6 (ZGS, 1999). Most of the catchment is underlain Kalahari Sands. South of Stanley, granites
and gneisses of the Zimbabwe Craton underlie the catchment. Between the Kalahari Sands and the Craton,
there is a small area of Karoo basalts and sediments.
4.11.1.3 Pedology, agriculture and land use
Soils in the sub-catchment can be divided into four groups:
• Very deep Kalahari Sands,
• Moderately shallow, coarse-grained kaolinitic sands, derived from the granites;
• Moderately shallow to moderately deep, medium grained loamy sands and sandy loams, derived from the
Karoo sediments; and
• Very shallow sands, derived from the basalts (DRSS, 1979).
The catchment is in Natural Region IV, with low (under 650mm) and unreliable rainfall, and poor soils (ZSG,
1997). Land use is mainly Communal Lands and the northern third of the catchment falling under the immense
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