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

y the upper Klaserie River. Recent alluvial deposits are present along wide terraces on the banks of all of the
larger rivers and streams, and particularly the lower reaches of the Olifants River.
The granitic and gneissic rocks of the Basement Complex outcrop at various points across the central area of
the sub-catchment, forming prominent hills or koppies. These exposed weathered granites erode easily, and
accelerated rates of sediment production occur in this region, with large amounts of coarse and fine sediments
accumulating in river channels.
Small outcrops of the Murchison Greenstone Formation occur in the northwestern and northern portions of this
sub-catchment, together with outcrops of Timbavati Gabbro close to the Lebombo Mountains. Several dolerite
dykes and sills have intruded the Basement Complex granites and gneisses across the central and southern
portions of this sub-catchment. These rocks are less resistant to weathering than their granite and gneiss host
rocks and give rise to negatively weathered linear features in the landscape, often forming or delineating
drainage lines that become filled with coarse rock and gravel fragments.
5.10.1.3 Pedology, agriculture and land use
Soils in the Timbavati-Klaserie sub-catchment can be divided into three broad groups:
• Areas of sandy-clay colluvial soils at the foot of the Drakensberg Mountains, grading into shallow, reddishcoloured
sandy-loam soils in the western part of the sub-catchment;
• Shallow, brownish to greyish-brown sandy soils overlying coarsely weathered rock in the central and
eastern portion of the sub-catchment; and
• Transported alluvial deposits of coarse to fine-grained sands and silts located along drainage lines.
Land use in the uppermost reaches of the Timbavati-Klaserie sub-catchment consists of small-scale irrigation
agriculture, subsistence agriculture and game farming. The central and eastern portions of the sub-catchment
are located within the Kruger National Park and land use therefore consists entirely of wildlife conservation.
Hoedspruit is the only town of any size in this sub-catchment.
5.10.1.4 Surface water users
Water use within this sub-catchment consists almost entirely of irrigation, subsistence agriculture and wildlife
conservation. Domestic and irrigation water supplies to the farms and small settlements located in the upper
reaches of this sub-catchment are provided by irrigation water released from the Jan Wassenaar Dam.
Boreholes and hand dug wells provide water for most of the smaller settlements located away from riverbanks.
Boreholes are usually the only source of water for the tourist camps in the many game farms and private nature
reserves. The Kruger National Park tourist rest camps at located at Balule and Olifants receive their water
supplies directly from the lower reaches of the Olifants River.
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