Plett’s weirwithal to prevent flooding

Damages caused by devastating floods experienced in the Bitou area about eight years ago are finally being repaired thanks to an initiative by the Western Cape Water and Sanitation Department.

The Keurbooms gauging weir is currently being refurbished after the floods in 2011 and 2012 washed the flanks away, leaving the foundations of the walls undercut.

Cutoff wall destroyed

The entire erosion-protection infrastructure downstream of the left-bank cutoff wall was also completely destroyed. The destruction of the erosion-protection works also resulted in the undercutting of 90% of the cutoff foundation wall.

During a visit to the weir last week, Ministry of Water and Environmental Affairs national spokesperson Sputnik Ratau said the remedial work was needed to address the “unsafe conditions” around the wall and to, among others, prevent potential loss of life downstream of the gauging weir.

He said various options to repair the gauging weir had been investigated. “The most viable and economical solution to repair the structure and reduce potential risk of any future damage was to construct a reinforced concrete chute immediately downstream of the wall which will mimic the scour channel that formed after the flood events,” Ratau said. He explained that the chute would have, among others, a floor that slopes downwards from the left bank of the river.

Major source of water supply

The Keurbooms River is a major source of water supply to the Plettenberg Bay area and the weir started measuring flow in October 1997. Gauging stations in general play a significant role as they are used as early flood-warning systems, thus minimising potential damage by floods. The refurbishment of the gauging weir is 95% complete and construction of the chute is anticipated to be completed before end of September this year.