WaterNSW monitoring Bureau weather forecast

3 MAY 2024

WaterNSW is working with the Bureau of Meteorology (Bureau) to monitor rain forecast and model any impacts on the Greater Sydney dam network.

The Warragamba Dam storage level currently sits at 98.1% of capacity, as part of a Greater Sydney dam network currently at 97% of capacity.

WaterNSW modelling indicates that it will likely require an average of 40mm of rainfall over the catchment to produce run-off into Warragamba Dam.

At this stage, Warragamba may experience a minor spill, with no significant impact on river levels. This does not include inflow from tributaries downstream of the dam.

It is likely that some of the smaller Greater Sydney storages, including Woronora and Upper Nepean dams could fill and spill on current estimates.


As manager of the state’s major supply dams, WaterNSW operates Warragamba Dam in line with NSW Government operating rules and protocols.

These rules do not permit water being released to reduce the storage level ahead of predicted rainfall for flood mitigation purposes. This reflects the dam’s critical role in supplying 80% of Sydney’s drinking water.

The Warragamba Dam catchment area covers 9000 sq/km and stretches across much of the Blue Mountains to Goulburn in the south, and to Lithgow in the north.

  • Check the Bureau website to receive the latest weather and flood information – bom.gov.au
  • For emergency information, contact the NSW SES – 132 500 or ses.nsw.gov.au

Media contact – Tony Webber 0428 613 478.

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