November/December 2016
19
A 38km water
transfer tunnel will
be constructed to
connect Polihali
Dam with the Katse
Reservoir.
Water Sewage & Effluent November/December 2016
infrastructure
Dam in the central Maluti Mountains. The dam has a storage
capacity of 1.9 billion cubic metres and a spillway discharge
of 6 252m³/s. Phase 1A also involved building a 45km transfer
tunnel and a 37km delivery tunnel.
Phase 1B involved the construction of the 145m concretefaced rock-fill Mohale Dam on the Senqunyane River. The
dam has a storage capacity of 958 million cubic metres and a
spillway discharge of 2 600m³/s.
A 32km interconnecting transfer tunnel between the
Katse and Mohale reservoirs was also built. This phase also
included the construction of the 19m-high Matsoku Weir and a
6.4km transfer tunnel. The Mohale Dam was inaugurated
in 2004.
Phase 2 of the Lesotho Highlands Water Project, which
is currently under way,
includes construction of
the 165m-high Polihali
Dam, in the Mokhotlong
district. It will be a
concrete-faced rock-fill
dam, with a capacity
to hold 2.2 billion cubic
metres of water. A 38km
water transfer tunnel will
be constructed to connect
Polihali Dam with the Katse
Reservoir. The second
phase also includes a
1 000MW pump storage
system. During phase 3 of
the project, the Tsoelike
Dam will be constructed
at the confluence of the
Tsoelike and Senqu rivers,
about 90km downstream
from Mashai Dam. It will
have a storage capacity of
2.2 billion cubic metres and
a pumping station. During
phase 4, it is proposed
that the Ntoahae Dam
and a pumping station
will be built about 40km
downstream from the
Tsoelike Dam, on the