The torrential rain that has battered Sydney has caused a giant sinkhole open up on a sporting oval.

It was at Tunks Park where locals first spotted the sinkhole on Thursday morning after another big night of rain.

The sinkhole was pictured close to goalposts at the park, which has been completely submerged by water as Sydney goes through a wet week.

The Long Gully Bridge is also visible in the background.

According to Weatherzone, Cammeray is set to receive up to 80mm of rain today, and it is a similar story around the city.

Sydney is receiving a similar amount today, having already been hit by nearly 50mm of rain on Tuesday and Wednesday.

It is causing dangerous flood conditions in other parts of the state.

Earlier today, a daring recue was staged to save a man and a dog from flood waters south-west of the city.

A father and son have also gone missing after being swept away late last night in St Albans near Wisemans Ferry.