No spill as yet at Warragamba Dam, inflows continue

2 JULY 2025

WaterNSW is advising the public that Warragamba Dam has not reached capacity and continues to capture rising inflow from its upstream catchment without spilling.

The dam is still expected to spill at some point in the coming days, with the storage approximately half a metre below full, and inflow occurring at a modest rate of 7.1 gigalitres per day (GL/day).

The Warragamba catchment received 56mm of rain during the previous 24 hours and WaterNSW teams are assessing the flow data to estimate the timing and extent of the spill.

The duration of the spill will ultimately be determined by rainfall received across the catchment today and in the days ahead.

Smaller Sydney dams, including Cataract, Nepean, Cordeaux and Woronora have commenced spilling and Avon is expected to do so shortly.

Fitzroy Falls, Tallowa, Greaves Creek and Medlow dams were already spilling, and will continue to do so.

The community should continue to monitor advice on river levels and any flood warnings from the Bureau of Meteorology.

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

Background

Spills from Warragamba Dam are not uncommon, occurring more than 50 times since 1960. This includes three times in mid 2024 and once in May 2025.

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.

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

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.

Background – dam operations

During times of flood, the gates on Warragamba Dam automatically open and close based on water levels.

After rainfall has occurred and when the water rises above full supply level, the gates progressively open in sequence. As water levels begin to drop, the gates will progressively close in reverse sequence.

Back to media releases
Go to top

WaterNSW acknowledges the traditional custodians of the lands and waters on which we work and pay our respects to all elders past, present and emerging. Learn more