
The story of
the creation of the lake and the building of Kariba Dam is
an exciting account of modern engineering. But it is also
the tale of the tragic but necessary removal of the Ba Tonga
people, who held that the river god Nyaminyami would destroy
the dam and allow the Zambezi to run free again. Kariba
takes its name after a rock which used to feature quite
prominently in the river gorge - but is now buried
underwater. Many believed it to be the home of the river god
Nyaminyami, who caused anyone who ventured near it to be
drawn into the deep water, never to be seen again…
There is
suggested evidence that the Kingdom’s of Sheba, Solomon and
Hiram were enriched by the gold and ivory of Ophir which is
supposedly a part of the present day Zimbabwe. The Zambezi
was once a gateway to the ancient treasure trove of central
Africa. There are plenty of cave paintings and such that are
evidence of early man's occupation has been found along most
of the river but much of its history has been shrouded in
mystery.
HISTORY
50 years ago, the
emerging requirements of a young nation drove people to
control the flow of one Africa’s great rivers “The Zambezi”.
So the Electricity Supply
Commission instigated an investigation for possible
hydroelectric schemes to be situated at Kariba and in 1941
funds were allocated. As a result of this survey, a river
gauging station was set up at Chirundu as well as at a
campsite 25 kilometers downstream from the present dam wall.
The dam was an initiative of the Federation existing at the
time between British ruled Northern and Southern Rhodesia
(now Zambia and Zimbabwe) and Nyasaland (Malawi). To dam the
great Zambezi floodplain was in many ways a hopeful leap
into the future. Vast areas of forest and scrub would be
inundated. Literally thousands of wild animals would lose
their habitats and, more importantly, the local villages
would have to be relocated. Analysis of the economic
advantages convinced the authorities that the ultimate
benefit to the people would outweigh the loss of wildlife
and disturbance to people's lives.

In 1958, at
the narrow neck of a remarkable gorge, a rising wall of
concrete stemmed the river's flow and so created what at the
time was one of the largest man-made lakes in history. The
Kariba Hydroelectric dam wall had created a vast expanse of
water which is now known as Lake Kariba.
It provides considerable electric power to both Zambia and
Zimbabwe and supports a thriving commercial fishing
industry. More than a million cubic metres of
concrete were employed to build the 24-metre thick and
36.6-metre high wall, which was designed to sustain the
pressure of nearly ten million litres of water passing
through its spillway every second. It is located at the
northernmost shore of Lake Kariba.
ABOUT LAKE KARIBA AND THE DAM WALL

The building of the Kariba Dam was always surrounded by controversy,
both environmentally and socially, it is still an impressive
monument to man’s engineering genius. There is a big tourist
potential that the lake offers, there are many positive implications
for the struggling economy and unemployment problems in the area.
The Tonga People, whose traditional lands lie buried beneath the
lake, would probably benefit most from tourist development.
Captured inside a mountainous basin and fringed by teak forest,
nature reserves and an eery landscape of submerged trees the lake is
any photographer's dream. Numerous islands and waterways cause the
wildlife to swim about quite frequently, which makes game viewing by
boat very popular.
Lake Kariba
is located on the Zambezi River, about halfway between the
river's source and mouth, about 1,300 km upstream from the Indian
Ocean. The lake lies along the border between Zambia and Zimbabwe.
The Lake was filled between 1958 and 1963 following the completion
of the Kariba Dam at its northeastern end, flooding a former gorge
on the Zambezi River and displacing large numbers of the local Tonga
people. Siavonga and Sinazongwe in Zambia have grown up to house
people displaced by the rising waters.
In the early 60's
Rupert Fothergill and his team, bravely undertook the biggest
animal rescue ever called Operation Noah, the worlds attention
was on the lake for the first time. An epic drama which was also
partly filmed, unfolded, as wildlife was saved from the rising
waters of the new Lake. Over 5,000 animals were rescued,
including 35 different mammal species and 44 black rhino.
Frightened creatures ranging from elephant to snakes were
captured for release into areas that now form Matusadona
National Park and Chete Safari Area. The surrounds of Lake
Kariba became a fascinating turmoil of ecological change - parts
of which now teem with an abundance of flora and fauna in a
striking and diverse terrain.

The Kariba Dam wall was designed by the French engineer and inventor
Andre Coyne. A specialist in “arch dams”, he personally designed
over 55 dams, Kariba being one of them. Rumor around Zambia has it
that a few of the dams he built in Italy collapsed leading him to
commit suicide. This fact has not been corroborated.
Lake Kariba is over 220 kilometers (140 mi)
long and up to 40 kilometers (20 mi) in width. It covers an area of
5,580 square kilometers (2,150 sq mi) and its storage capacity is an
immense 185 cubic kilometers (44.4 cu mi). The mean depth of the
lake is 29 meters (95 ft); the maximum depth is 97 meters (320 ft).
The enormous mass of water (approximately 180,000,000,000,000
kilograms, or 180 petagrams (one
petagram is one billion metric tons,
180 billion metric tons) is believed to have caused induced
seismicity in the seismically active region, including over 20
earthquakes of greater than 5 magnitudes on the Richter scale.

PHYSICAL CHARACTERISTICS OF LAKE KARIBA
Coordinates:
17° S 28° E
Lake type:
Hydroelectric reservoir
Catchment area: 663,000
km²
Basin countries: Zimbabwe
Zambia
Max-length:
220 km
Max-width:
40 km
Surface area: 5,400
km²
Average depth:
31 m
Max-depth:
78 m
Water volume: 160
km³ “180 billion metric tons”
Surface elevation:
485 m
Islands
Chete Sekula Chikanka Banana
ECOLOGY OF
LAKE KARIBA
Before Lake Kariba was filled, most of the existing vegetation was
burned, creating a thick layer of fertile soil on land that would
become the lake bed, as a result the ecology of Lake Kariba became
vibrant. A number of fish species have been introduced to the lake,
notably the sardine-like kapenta (transported from Lake Tanganyika),
which now supports a thriving commercial fishing industry. Other
inhabitants of Lake Kariba include Nile crocodiles and
hippopotamuses.
Its waters support more than 40
different species of fish – in a rare example of a successful
introduction of a non-native species to a lake, the kapenta - taken
from Lake Tanganyika - has apparently had a minimal biological
impact.
Gamefish, particularly Tigerfish,
which was among the indigenous species of the Zambezi river
system, a fighting game fish that offers excellent fishing, now
thrive on the kapenta, which in turn encourage tourism. Both
Zambia and Zimbabwe are now attempting to develop the tourism
industry along their respective coasts of Lake Kariba. There are
several different barble (catfish) species, one of which, the “vundu”,
grows to a few hundred pounds and can give fishermen a thrill
when they head out to the middle of the lake with your hook in
their mouth.
Bream fish, or Tilapia are a very
popular eating fish and are plentiful on the Lake.
Fish eagles, cormorants and other
water birds patrol the shorelines, as do occasional herds of
elephants, with most of the wildlife seen on the Zimbabwe side.
The lake’s vastness creates spectacular panoramas as the sun casts
its glow across the shimmering waters catching the distinctive
half-submerged trees and islands.
Lake Kariba is studded with islands and surrounded by mountains.
Once on dry land, these thousands of teak trees were half submerged
in water as the lake slowly expanded to its present dimensions.
Today, the skeletal branches of the trees jut into the sky from
another world.
Continued
The Zambian side of the lake
has about 800 km of shoreline, baked African fjords with
placid backwaters and numerous islands. Often elephants can
be seen swimming between the shore and islands, a sight
perhaps unique to Lake Kariba.
FLORA OF LAKE KARIBA
-
Floating macrophytes:
Salvinia auriculata (2).
-
Submerged
macrophytes (2)
Ceratophyllum demersum, Potamogeton pusillus,
Lagarosiphon ilicifolius, Vallisneria aethiopica, Najas sp.
-
Phytoplankton (4)
Cylindrospermopsis raciborskii, Anabaena sp., Lyngbya sp.,
Synedra acus, Melosira granulata, Peridinopsis cunningtonii,
Chrysochromulina parva, Tetraedron minimum.
FAUNA OF LAKE KARIBA
-
Zooplankton (2)
Brachionus falcatus, Bosmina longirostris, Tropodiaptomus
kraepelini, Limnocnida rhodesiae.
-
Fish (2)
Sargochromis codringtoni, Synodontis zambezensis, Tilapia
rendalli, Claiasr gariepinus, Synodontis nebulosus, Schilbe
mystus, Heterobranchus longifilis, Malapterurus electricus,
Eutopius depressirostris, Sarotherodon mossambicus.
CLIMATE
The climate is
generally tropical with three reasonably distinguishable seasons. A
hot rainy season from late November to March, a cool dry season from
May to August and a very hot dry season from September to November.
Annual rainfall ranges from 400mm (16 inches) in the Valley to about
700mm (28 inches) on the plateau. Winter temperatures rarely go
below 13 degrees C (55 degrees Fahrenheit), day time temperatures
hover at about 40 degrees C (104 degrees Fahrenheit) during the hot
months.
-
Climatic data
1960-1970 (2)
|
Mean temp. [deg C] |
|
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Ann. |
|
25.8 |
25.4 |
25.7 |
24.7 |
22.7 |
20.2 |
24.7 |
20.0 |
22.6 |
26.2 |
29. |
227.7 |
24.7 |
|
Precipitation [mm] |
|
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Ann. |
|
149.6 |
126.0 |
90.7 |
14.2 |
4.6 |
0 |
0 |
0 |
0 |
10.9 |
42.3 |
157.0 |
608 |
-
Number of hours of
bright sunshine: 2,920 hr yr-1 (2).
-
Solar radiation:
23.9 MJ m-2 day-1 (2).
PHYSICAL DIMENSIONS
|
|
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Ann. |
|
Mean temp. [deg
C] |
25.8 |
25.4 |
25.7 |
24.7 |
22.7 |
20.2 |
24.7 |
20.0 |
22.6 |
26.2 |
29.2 |
27.7 |
24.7 |
|
Precipitation
[mm] |
149.6 |
126.0 |
90.7 |
14.2 |
4.6 |
0 |
0 |
0 |
0 |
10.9 |
42.3 |
157.0 |
608 |
-
Average Water
temperature [deg C]
|
Depth [m] |
Jan |
Feb |
May |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
S* |
30 |
29 |
30 |
29 |
26 |
24 |
23 |
23 |
25 |
26 |
28 |
29 |
* Surface.