CAPE TOWN - George Municipality and the local engineering community are celebrating the success of the award-winning Garden Route Dam spillway, after the dam overflowed for the first time since the spillway was constructed and the dam wall raised about two years ago.
The municipality’s civil engineering services acting director, Lionel Daniels, said the heavy rainfall and flash floods last Monday had overshadowed the dam’s overflowing on the same day.
But it remained a significant milestone in the city’s long-term planning for water security, he said.
“There are many reasons we are celebrating this project, including an increased capacity of 25% by raising the full supply level of the dam by 2.5m.
“The ingenious duckbill-shaped spillway design improved the dam’s safety in a practical and cost-effective way that earned the designers, Zutari, a win in the technical excellence category at the South African Institute of Civil Engineering (SAICE) Awards last year.
“The design is relatively new in the engineering world, and as far as we know it is not being used in this way anywhere else in South Africa.
“It was extensively researched and tested at the University of Pretoria and its shape is designed to slow down the water-flow, using basic physics principles. The design is brilliant in its simplicity and it was a real victory to see the dam overflow and the spillway working so effectively,” said Daniels.
The Garden Route Dam, situated just outside the north-east urban edge of George, is the main source of potable water for the city. Its capacity had become a concern as the municipal area has continued to grow exponentially.
Also, the Southern Cape region experienced two major droughts in seven years.
The Garden Route Dam spillway and wall project was completed in January 2020, and increased the dam storage capacity by 25% – from 10 million cubic metres to an estimated new capacity of 12.5 million cubic metres.