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

4.22 Mining operations in the Levuvhu sub-catchment
4.22.1 General description
4.22.1.1 Hydrology
This sub-catchment consists of the area drained by the Levuvhu River and its main tributary the Mutale River,
together with a variety of smaller tributary streams. The Levuvhu and Mutale rivers flows north-eastwards from
the north-eastern slopes of the Soutpansberg Mountains to the Limpopo River, joining the Limpopo River at
Crooks Corner where the borders of South Africa, Mozambique and Zimbabwe meet (Figure 4.2). The flow
patterns in these two rivers are fairly variable as a result of the prevailing unpredictable rainfalls, though the
upper reaches of the sub-catchment receive over 1,000 mm of rainfall per year. There is an extremely steep
gradient in rainfall from the upper reaches of the sub-catchment to the Limpopo River where annual rainfalls
average some 250 mm per year. Both the Mutale and the Levuvhu rivers are normally perennial, though the
Levuvhu River has been extensively exploited and now contains very little water. During drought periods, the
lower reaches of both rivers may stop flowing for periods of several months. Summer rainfalls cause a dramatic
increase in flows, though the tributary streams are episodic and only contain water after rainfalls.
The Levuvhu sub-catchment contains four large dams and over 180 smaller dams that are used to supply water
mainly for domestic use and livestock watering purposes (Boroto & Görgens, 1999), as well as some water that
is transferred out of this sub-catchment into the Sand sub-catchment. In addition, the Venda sacred lake, Lake
Fundudzi, is located on the upper reaches of the Mutale River.
4.22.1.2 Geology
The geological characteristics of the Levuvhu sub-catchment share several similarities with neighbouring subcatchments
to the west. A variety of acidic, intrusive granites and gneisses of the Sand River Formation
underlie the uppermost reaches of the sub-catchment, whilst younger consolidated and silicified sedimentary
strata, predominantly sandstones and quartzites of the Soutpansberg Group have in turn intruded and overlain
these to form the spectacular, steep-sided hills and mountains of the eastern limb of the Soutpansberg
Mountains, located in the headwaters of this sub-catchment.
Further downstream, the sub-catchment is underlain by sequences of silicified sandstones and quartzites of the
Soutpansberg Group, followed by carbon-rich mudstones, shales and basalts, of the Karoo Sequence.
Compact sedimentary extrusive and intrusive rocks of the Beit Bridge Complex mark the position of the highly
mineralised Limpopo Mobile Belt, underlying the northern part of the catchment closest to the Limpopo River.
Recent (Quaternary) deposits of semi consolidated sandy material overlie large areas of the central and
northern parts of the sub-catchment.
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