Kariba coffer dam start deferred to March

Opening of Gate Number 3 on January 22, 2011.


THE planned December start of the construction of a coffer dam in the plunge pool at Kariba has been deferred to March as a new survey has found discrepancies in the pool’s bathymetry, Project Manager Arjan Goossens of contractors Razel-Bec told Business Times.

He said the planned coffer dam was based on a 2011 bathymetry of the pool, but the bathymetry had probably changed as a result of the opening on the gates in 2013. Stucky Ltd, the consulting engineers, were in the process of redesigning the coffer dam foundation, which would be deeper than planned.

The bathymetry study of the pool in 2011.

The southern gates Number 1 and Number 3 were opened for 17 and 18 days respectively during March and April 2013.

One of the other challenges facing the contractors was the weak ground on the North Bank where the access road for heavy haulage trucks was to be constructed, but this has been redesigned to run over the trailraces, Goossens added.

The EU is largely funding the $294 million project for the reshaping of the plunge pool and rehabilitation of the spillway gates.