EIA-REP-325d-12 _BB_ - 201.09.14.pdf - SAHRA

Figure 9: Tertiary and quaternary drainage regions in the vicinity of Usutu Colliery (situated in Water Management
Area 8)
8.1.4.1 Groundwater
The proposed Usutu Coal Colliery opencast mine area is bounded to the northwest by the decommissioned and
sealed underground workings of the Usutu underground mine. The current mining plan will see a boundary pillar
of at least 30 meters wide between these old workings and the open pit. The Usutu south underground mine lies
to the east and south-east of the proposed mining area, at a depth of in excess of 80 meters below ground level.
Groundwater occurrence is controlled by the presence of zones of weathering and fracturing within the Karroo
country rock and dolerite sills, and by the presence of fracturing associated with the dolerite intrusions. Karroo
sandstone, siltstone and shale are characterised by low permeability and transmissivity and yields from
boreholes are usually