Ingula Update
Every drop of water counts
Before Ingula can deliver on its
promise of 1332MW by 2013, twenty
six million cubic metres of water has to
be collected in the bottom reservoir,
Bramhoek Dam. This water comes
from the Bramhoekspruit, and the
small tributaries that feed it.A threat to
this is the large number of alien and
invasive plant species within this
catchment. Although the bottom
reservoir only needs to be filled once,
the 8000ha of the Ingula conservation
area depends on a healthy water
system.
Streams are starting to flow again after the removal of Wattle trees
Invasive alien species are causing billions of Rands of damage to South Africa's economy every
year and are the single biggest threat to the country's biodiversity and water availability. Of the
estimated 9000 plants introduced to this country, 198 are currently classified as being invasive.
This list includes the Black Wattle (Acacia mearnsii) and Silver Wattle (Acacia dealbata), both of
which are found in large numbers at Ingula, and pose the biggest threat to its water supply.
Wattles are extremely vigorous alien plants and out-compete indigenous species for available
resources, growing up to three metres in one season and forming mono-specific stands.They
spread at alarming rates and destabilize the ecological balance by increasing the intensity of
wildfires and soil erosion. They are also incredibly thirsty which can lead to dramatically
reduced ground water levels and the drying up of smaller watercourses. It is estimated that
nationally, invading species use 3,3 billion cubic metres more water than native vegetation.Any
alien tree in the area is withholding water from the natural system.
In order to secure Ingula's water supply and as part of its Environmental Management
Programme, the Ingula Conservation and Land Management (ICALM) team has begun an
invasive species eradication programme. In environmentally sensitive areas the trees are
treated with an approved herbicide or ring-barked and left to die in situ. In less sensitive and
more accessible areas the trees are cut close to the base of the stump and usable wood
removed. Cutting and selling the wood has provided an entrepreneurial opportunity for the
communities in and around Ingula.
Trees growing on disturbed areas are weeded out if small, or chemically treated if they have
more established root systems. Short and long term rehabilitation implications of the various
control methods are being determined, and it is hoped that the Ingula eradication programme
will contribute to the knowledge of alien plant management and rehabilitation in South Africa.
To date, more than two hundred hectares of trees have been treated. Thousands of trees are
dead or dying and mountain streams appear to be recovering. It is envisaged that by the time
the pumped storage scheme is operational, the invasive Wattles will be a thing of the past.
However, the seeds of these persistent plants can lie dormant in the soil for up to 60 years! For
the next several decades the programme will continue to monitor and investigate the best
ways to control Wattle recurrence and keep Ingula on the forefront of indigenous biodiversity
management.
Area showing successfully treated wattle trees
March 2010
Tel. 036-3423122
Progress on key projects
Underground works
Machine Hall
Breakthrough between the machine hall
and main access tunnel took place on the
29th March 2010.
The transformer hall central heading is
74% complete and the transformer hall
enlargement is currently at 50%.
Excavation for the main drainage tunnel
has been completed and stands at 13% for
the main drainage gallery.
Excavation has once again commenced
on penstock 4 and has progressed to 47%
complete. Work has started on the surge
chambers.
Outlet in the bottom reservoir
The outlet channel walls stand at 75%
with the bellmouth and tower at 62%.
Excavation of surge shafts 1 and 2 stand at
33% and 3 and 4 at 35%.
Soft excavation of the intake channel is
almost complete with hard excavation at
75%.
Excavation in the intake channel
High ‘power’ delegation visits Ingula
The Managing Directior :
Generation, Thava Govender and
a group of senior managers
recently visited Ingula.
Progress on key projects
Upper reservoir: Bedford Dam
The massive wall of Bedford Dam.
The construction of Bedford dam is well
underway. The latest accepted
programme indicates planned
completion for 10 May 2011.
The group was taken on a site tour, which included a
visit to the underground works.
Pictured above, from left to right are Ayanda
Nakedi(General Manager: Strategy, Technology and
Assurance), Nhlanhla Madonsela (Generation
Employee Relations Manager), Nandu Bhula
(General Manager: Peaking),Segomoco Scheppers
(Transmission System Planning), Thava Govender
(MD: Generation), Pooben Naidoo(Plant Manager:
Ingula), Kannan Lakmeeharan (Systems Operations
Nandu Bhula looking up into the and Planning Division) and Phil Khumalo (Power
high pressure incline shafts
Station Manager: Peaking).
The intake tower in the dam wall has
reached its maximum height with all
concrete lifts completed. The internal
concrete works are well underway with
one more floor slab, the fourth and last,
to be cast early in April.
Bedford Dam intake tower
Outlet works
Gearing up for fire season
Winters in the summer rainfall area of South Africa are dry, cold and windy, making it a
particularly dangerous time for veld fires to spread.
In preparation for the upcoming winter fire season, Generation MD, Thava Govender,
handed over a brand new, fully equipped, fire response vehicle to the Ingula fire response
team. This dedicated mobile 4x4 unit will enable the team to significantly reduce
response time and can be managed by a minimum of two or three people.
Downstream, at the outlet works, the
gabions for the stilling pond are complete
and work began on the two wing walls.
Bedford Dam outlet works
At Ingula large areas of precious grassland are burnt every year by land users. Although
fire is a natural occurrence, ideally the veld should burn once every three years. This
allows the grass to mature and helps to maintain biodiversity. It is very important that the
wetlands do not burn every year as it is the habitat for many of Ingula's important species
such as the cranes and White-winged Flufftails.
The new fire response unit has already been christened as the ‘BFT’ which is short for 'Big
Fire Truck'.
780 000m³ of rockfill (82 %) has been
placed in the embankment. Work has
started on the face slab with four starter
slabs in place.
Four concrete pours were done on the
emergency spillway section, currently
40% complete.
Beford Dam embankment