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

The Nampundwe pyrite mine poses a risk of contamination from acid mine drainage, as do the Dunrobin and
Luiri gold mines. The Chilanga Cement Works poses a potential problem from alkaline dust.
3.14 The Kariba (Zambia) sub-catchment
3.14.1 General description
3.14.1.1 Hydrology
This area comprises a series of small sub-catchments, whose rivers flow from the surrounding plateau down
steeply inclined riverbeds into Lake Kariba. None of these rivers are perennial, though continual seepage from
Maamba Colliery gives the appearance of perennial flow in a nearby stream.
3.14.1.2 Geology
The plateau is composed of quartzites and associated rocks, underlain by Karoo Supergroup sedimentary rocks
and basalt. These rock formations are deeply incised by the numerous streams flowing from the plateau to
Lake Kariba.
3.14.1.3 Pedology, agriculture and land use
Soils in the sub-catchment can be divided into three groups:
• Very shallow, gravely soils derived from Upper Karoo sediments and basalts;
• Moderately deep sandy soils derived from Lower Karoo sediments;
• Moderately deep kaolin tic sandy to loamy sand soils derived from quartzites and associated rocks.
The sub-catchment experiences low and erratic rainfall; usually below 650 mm per year; the exception being the
higher elevation plateau that receives slightly more.
Land use comprises the sparsely populated communal lands with subsistence agriculture, commercial stock
farming (beef cattle and goats) on the plateau and some cash cropping of tobacco. Several small towns are
located along the watershed marking the plateau, Zimba, Monze, Choma and Kalomo being the most important
centres. A small urban centre has developed close to the Maamba Colliery to house the colliery staff.
cxxiii