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

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4.11.6 Implications for water quality and quantity management
Unless a mine is opened as result of current exploration activities, there is and will be neither mining nor any
impacts of mining taking place.
4.12 The Lower Limpopo and Chagane (Mozambique) sub-catchment
4.12.1 General description
4.12.1.1 Hydrology
This sub-catchment consists of the main stem of the Limpopo River, from the border with South Africa and
Zimbabwe, to the coast at Xai-Xai (Figure 4.2). The Mwenezi River from Zimbabwe joins the Limpopo River,
some 70 kilometres downstream of Pafuri, whilst the Olifants River flows into the Limpopo River a further 120
kilometres downstream. Shortly before the Limpopo River reaches its mouth at the coast, the Chagane River
joins it. The Chagane River drains a very large area of coastal plain and consists almost entirely of seasonal or
episodic streams and pools (Figure 4.2). The Limpopo River downstream of its confluence with the Olifants
River supports a very large irrigation scheme at Chokwe. The Chokwe Irrigation Scheme is estimated to consist
of some 290 km 2 of demarcated irrigation area, though not all of this appears to be utilized (Boroto & Görgens,
1999).
The Olifants River basin is dealt with separately in this report (Section 5) and is not included here under the
Limpopo basin.
Dry season (June 1998) flows in the Limpopo River at Crooks Corner close to Pafuri, where the borders of
South Africa, Mozambique and Zimbabwe meet, consist almost entirely of flows contributed by the Mutale-
Levuvhu river system (P.J. Ashton, personal observations). The Limpopo River upstream of Crooks Corner is
usually dry for several months during winter each year (Boroto & Görgens, 1999).
4.12.1.2 Geology
Most of this sub-catchment is underlain by extensive Quaternary deposits of semi-consolidated sandstones and
mudstones, with slightly older deposits of Tertiary age from the Mazamba, Jofane and Cheringoma formations.
In addition, there are also areas of the Grunja and Sena post-Karoo complexes, consisting predominantly of
alkaline dolerites and shales, with minor evidence of non-economic coal measures in small outliers of the
Stormberg Series along the western portion of the sub-catchment close to the Lebombo Mountains. Recent
alluvial deposits and discrete flood terraces characterize the valley bottom along the Limpopo River.
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