SA Water has commenced work at Myponga Reservoir as part of a $3.7 million upgrade of the dam spillway gates.
The works are designed to secure the Fleurieu Peninsula’s water supply as well as the long-term safety of the structure.
Myponga Reservoir’s three spillway gates sit atop the dam wall and facilitate controlled releases of water from the reservoir based on capacity and rain inflows from the catchment.
In March 2024, the three gates were carefully removed by a large crane located on Reservoir Road, with each lift taking around 30 minutes and involving 12 crew members across the operation.
SA Water’s Senior Manager of Infrastructure Planning and Strategy, Daniel Hoefel, said the dam’s spillway gates have made for spectacular pop-up waterfalls in recent years and were earmarked for refurbishment.
“Myponga Reservoir’s arch dam is an impressive engineering feat and 60 years on, the wall remains in sound condition with our routine inspections identifying the dam’s spillway gates require an upgrade to ensure they keep operating reliably,” Mr Hoefel said.
“The gates are curved steel plates, reinforced with a series of beams that can be opened at varying heights depending on the amount of water being released, and are critical to our ability to maintain the reservoir’s water level and protect the dam’s structural integrity.”
Featured image: Before the gates were craned off the dam wall, water was released from the reservoir for two weeks until the water level was sitting below the top of the spillway crest – which was around 71 per cent of capacity. Courtesy of SA Water.
