Dam spill peak estimate now below March 2021

Dam spill peak estimate now below March 2021

03 March 2022

The peak outflow forecast from Warragamba Dam has been downgraded to a level below that experienced during the March 2021 spill event.

Less rainfall than predicted over key Warragamba catchment areas has resulted in the peak spill forecast being revised back to a rate of 300-350 gigalitres per day (GL/day), well down on the previous prediction of up to 600 GL/day for this event.

The peak outflow figure during March 2021 spill event was a rate of 440 GL/day.

The prediction is still subject to advice from the Bureau of Meteorology and will be ultimately determined by the intensity of the rain event and the inflows generated. Most major dams in the Sydney network have spilled, including all those in the Upper Nepean.

River levels are also influenced by inflows from tributaries downstream of the dam, such as the Upper Nepean River, the Grose River, the Colo River, the McDonald River, Eastern Creek and South Creek. Significant flows are also occurring in the Erskine Creek and the Glenbrook Creek.

WaterNSW is monitoring any impacts on the quality of water in dam storages as a result of the inflows and working with Sydney Water to manage supply.

WaterNSW will be working closely with the Bureau of Meteorology to monitor weather forecasts for key catchments and inflow projections.

Access WaterNSW information on Sydney Dam levels or river heights and flow data at WaterInsights




Bureau of Meteorology (BOM)

Weather forecasts and warnings


NSW State Emergency Service (SES)

Flooding and severe weather warnings and advice



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Saturday 02 July