Kariba dam’s potentially catastrophic failure could have a deadly impact
The bare facts of a collapse of the Kariba Dam wall paint a dim picture of the probable reality.
In November 2012, Sino-Hydro, a Chinese firm, was contracted to construct two additional units at the Kariba Dam. The dam, which was constructed in the late 1950s, straddles the border between Zimbabwe and Zambia.
By 2014 the focus had shifted away from building extensions to a more immediate concern; that of a reported structural damage in the form of cracks in the wall. Shortly thereafter, Gilles Hervio, the EU Head of Delegation in Zambia traveled to Brussels where the situation was addressed as an urgent issue.
“Kariba Dam is a potential disaster …..I traveled to Brussels and by June and July, money will be released. We are studying it and no decision has been made yet but the amount involved could be between 85 million dollars and 100 million dollars,” he said.
The Zimbawe Situation
2015 has seen breaking news stressing that the 128 meter high wall could potentially collapse as the stilling pool below the gates is eroding under the dam wall itself.
Engineers, scientists, politicians and journalists worldwide have sprung a fountain of opinion and conflicting reports. For the average person sitting at home reading the newspaper, a long and boring set of statistics and probabilities brings to mind no mental image of the scale of such a disaster.
The stilling pool that is eroding lies deep and black and the thundering water that cascaded so violently through the wall has repeatedly dug out the base of the wall.
Every year millions of cubic meters of quick set concrete have been poured down to stop the force of the water eroding back under the wall; yet 81 meters of erosion have continued inexorably .
Beneath the foundations, in unimaginable darkness, the combined compressed pressures of rock and concrete and water maintain a steady force on the floor of the gorge: A gorge which which has experienced earth tremors of up to 5.5 on the richer scale in the past.
If the wall should fail catastrophically there will be an instant when the workers in the dam wall will see the needles on the pressure gauges leap into the red before their lives are extinguished.
The concrete could peel away in an instant, like bone under a band saw. Three hundred feet of water, a towering, massive pent up force of kinetic energy could thrust the great slabs of concrete away and explode to freedom in a mighty wave the height of the cliffs that bound it.
Imagine the devastation downstream if you can. It is almost too horrific to think to think of. The great Zambezi valley that lies below Kariba dam stretches flat and vast for thousands of square kilometers.
Below the dam wall at a place called Nyamomba, where the gorge ends and the flatlands of the valley proper begin, the water would spread out in….
