Parched NSW dams swelling with rain

Parched dams around Sydney are swelling to their highest levels in years as heavy rainfall continues to drench eastern NSW.

Government water supplier WaterNSW says Warragamba Dam west of Sydney is forecast to receive its best inflows since April 2017.

Warragamba Dam, the primary source of water for urban Sydney, was sitting near 44 per cent of capacity on Sunday afternoon and was predicted to rise to 55 per cent.

The increase was equal to recouping nine months of water supply in less than a week, WaterNSW said.

While water catchments in eastern parts of the state have received a boost, other drought-stricken inland areas have not been so lucky.

The Burrendong Dam, which serves major regional areas in western NSW such as Dubbo, was at just one per cent capacity on Sunday, according to WaterNSW.

Ash and debris left after the recent bushfire crisis are likely to wash into the Warragamba catchment but will not impact water quality.

"Any surface debris is being avoided by extracting water from 30 metres below the surface as a precaution," a WaterNSW spokesman said.

Two booms - also known as silt curtains - have been placed upstream of the dam to catch silt before it reaches the dam itself.

Other dams serving the metropolitan Sydney area, including the Nepean, Cataract, Avon and Woronora dams, have all recieved a welcome top up, WaterNSW added.

The Tallowa Dam in the Shoalhaven area has also started to fill.