The dam that became a bridge
The dam that became a bridge
Kariba Dam, unsurprisingly, was not built as a bridge to link Zambia and Zimbabwe, but a roadway was included in the design and the ability to cross the border has benefited locals on both sides.
The chief motivation to build the dam was as a source of hydro-electric power for both countries. That it incidentally also became one of only three road links across the Zambezi between Zambia and Zimbabwe was a happy consequence. Other benefits were the large water based and wildlife tourism that it generated, as well as the creation of a large commercial fishing industry.
To build one of the world’s largest dams is a massive undertaking and the statistics are truly mind boggling. This double curvature concrete arch dam took four years to build, cost 86 lives and US$480million to construct, displacing 57,000 people. Well over a million cubic metres of concrete was poured into the 36.6m high wall that boasts the thickness of over 24m needed to sustain the pressure of nearly six hundred million litres of water passing through the spillway each minute. The reservoir is 280km long, has a surface area of 5,400km2, is 97m deep at its deepest point and holds 180km3 of water. In short, this is a massive dam with a phenomenal amount of water that the wall has to hold back.
In 2005 the road was arbitrarily closed to traffic that exceeded 3 tonnes in weight but pressure from local business people caused it to be re-opened to all traffic. This has stimulated commerce in the region as well as helping to alleviate pressure on the Chirundu bridges.
The name Kariba comes from the word kariva (trap) and refers to a rock that thrust out of the swirling waters near the dam wall site. This rock, which is now buried 3m below the surface of the water, was regarded by legend as the home of the great river god, Nyaminyami. When the valley people heard that they were to be moved, they predicted their god would wreak revenge.
Two consecutive and unaccountably huge floods, the extent of which it was predicted would only occur every ten thousand years, washed away the access bridge, coffer dam and parts of the main wall. Nyaminyami had temporarily reclaimed his gorge, but two years later the dam was completed. The local people still warn that the river god has not yet finished.
Factfile - Kariba Dam
Architect: Andre Coyne, a French designer who designed 55 arch bridges, one of which - the Malpasset Dam in southern France – collapsed, killing 421 people. Coyne was deeply upset and died just six months later.
Location: 65km upstream from Chirundu.
Fun Fact: There are 78 countries (including international territories) that are smaller than Lake Kariba.
Read more about the region in our destination guide:
Kariba & Middle Zambezi
Read more articles from this issue:
Zambezi Traveller (Issue 14, Sept 2013)