This borehole with a blow yield of 28 litres per second, was
drilled to irrigate sports fields in an area in Cape Town.
The labyrinth of tunnels and springs
beneath the City of Cape Town is
also worth further investigation,
as well as tunnelling into the Table
Mountain Group Aquifer and seeking
collaboration with local sand
mines and quarries that undertake
dewatering operations continuously. u
“There are many areas in the
city, probably at least 70% of the
Cape Town area, where there is
sufficient groundwater for this to
be feasible,“
says Desmond Visser - SRK.
Water Sewage & Effluent July/August 2017
13
50 schools have been provided with
boreholes, saving at least 500 000m 3
of water (equivalent to 200 Olympic
size swimming pools) that would have
had to come from treated municipal
supplies. SRK is confident that this
irrigation programme should be
extended to include nearly all schools,
public parks, and many buildings in
the Western Cape.
In the light of ongoing shack
fires in informal settlements, these
‘neighbourhood boreholes’ could also
contribute to community safety.
“An idea that has been mooted by
SRK is the use of such strategically
sited boreholes to help fight shack
fires,” says Rosewarne. “These
boreholes — equipped with vertical
turbine pumps — could supply water
more quickly than conventional fire
tenders.”
A further use of boreholes
extracting groundwater could be to
lower the water table in low-lying,
flood-prone areas — on the Cape Flats
particularly; this could reduce the flood
risk, as aquifers would be better able
to absorb the excess run off water,
he comments. Much of this flooding
is attributable to rising water tables,
rather than rivers bursting their banks.
Drilling of a borehole at a school in Atlantis.