Mt Bold Spillway Opens After Record Rain

891 ABC Adelaide

Topic: Water Resources

In short:

The Mount Bold catchment got over 13 billion liters of water since last weekend.

The reservoir got over 5 billion liters in 24 hours to Monday morning.

What's next?

Released water goes to Happy Valley Reservoir.

Last weekend's heavy rain filled Mount Bold Reservoir from 69% to 95% capacity, opening its spillway.

About 18 billion liters of water flowed into SA Water's reservoirs in 24 hours, the highest since 2016.

Waterfalls in the region are flowing, like Morialta Falls and Mannum Waterfalls.

Mt Bold Reservoir got 5 billion liters on Sunday, and more since, tripling its storage since winter started.

Waterfalls in the Adelaide Hills are flowing strongly as reservoirs get 18 billion liters in 24 hours.

SA Water's James Crocker said releasing water creates space to balance natural inflows and protect the dam.

'We have four gates open to safely release water downstream,' he said.

They will reassess later how long the gates need to stay open.

The dam has eight gates that can be controlled to release different volumes of water based on storage levels and expected inflows.

Public access to the dam wall is closed, but visitors can see the 'pop-up waterfall' from a viewing platform.

Mount Bold Reservoir is SA Water's largest, with a 46.9-gigaliter capacity.

Water from Mt Bold flows to the Clarendon Weir, where it can go to the Happy Valley Reservoir.

'We are transferring as much water as possible to this reservoir to maximize its use,' Mr. Crocker said.

Mt Bold is SA Water's largest reservoir, with a 46.4-gigaliter capacity, and its spillway gates last opened in 2022.

Record-breaking rainfall

Several South Australian towns had record August rainfall, including 110mm at Lenswood and 150mm in the far north.

Floodwaters surrounded buildings on Goodwood Road in Adelaide on Sunday night.

The rain caused flooding, stranding campers at Wilpena Pound and helping drivers in Adelaide.

Rain has continued in some areas throughout the week.

SA Water's metropolitan reservoirs are now 79% full, compared to 54% last year.

Released water flows into the Onkaparinga River and downstream to the Clarendon Weir.

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