Cyclone Alfred floods to flow into Murray-Darling system but Menindee Lakes stand in SA’s way

Queensland is bracing for Biblical rainfalls at the top of one of the biggest sources of the Murray-Darling’s water. But will it make it this far? See what the expert thinks.

Biblical rain predictions during Cyclone Alfred will cause an influx of water into the Murray Darling system – but experts say it’s unlikely to cause flooding in SA.

Forecasters are predicting up to 800mm of rain in 48 hours in Queensland and NSW as the cyclone unleashes chaos along the east coast of the country.

Renee Thompson, acting water delivery manager for the SA Department of Environment and Water, said the cyclone had sparked a floood watch in the northern NSW Condamine-Balonne river systems – a tributary of the Darling.

Flooding from Cyclone Alfred has closed roads in Queensland and NSW. Picture: Nigel Hallett

“Following any rain in the Murray-Darling’s northern basin, it can take weeks for flow to travel down the Darling River to the Menindee Lakes in western NSW,” Ms Thompson said.

“Any additional flow in the Darling River resulting from Tropical Cyclone Alfred will most likely be diverted into Menindee Lakes which is currently at 37 per cent capacity.

“With the distance involved and the capacity in the Menindee Lakes, it is unlikely the cyclone will cause any flooding in South Australia.”

Current regulated flow in the river at the SA border is 8000 megalitres per day, increasing to 9000 megalitres per day on Saturday. Flows will remain at that level for several days before reducing back to 8000 megalitres per day.

This is slightly above our normal entitlement flow for March.