Chaffey Dam EWS Removal

Chaffey Dam EWS Removal

About the Project

WaterNSW, the state’s bulk water supplier and system operator, is undertaking the removal of the Chaffey Dam early warning system at Woolomin which is located approximately 7 Km downstream of Chaffey Dam.

The early warning system was originally installed as a safety measure to alert the community if a Probable Maximum Flood were to occur. A Probable Maximum Flood is the largest possible flood that modelling indicates could occur in any given catchment. For Chaffey Dam the Probable Maximum Flood is significantly larger than any on record for the valley but is still statistically possible.

In recent years Chaffey Dam has undergone a number of upgrade projects. The construction of an auxiliary spillway and the raising of the dam wall by 8.4 metres along with raising the sill level of the morning glory spillway by 6.5 metres, means the dam is now capable of safely passing a Probable Maximum Flood event.

The Early Warning System at Woolomin is no longer required and so the two towers at Woolomin are being removed. Currently, this work is scheduled to be undertaken over a two day period in late July or early August.


  • Improve the reliability, operation and efficiency of the dam safety emergency plan (DSEP)
  • Provide clear understanding of roles and responsibilities as part of the DSEP
  • Improve the knowledge of dam safety in Woolomin

The dam has daily surveillance inspections performed by accredited staff, as well as annual surveillance inspection by a Dam Surveillance Engineer. The routine inspection and monitoring regime in place at the Chaffey Dam meets the requirements of the ANCOLD Guidelines on Dam Safety Management (2003). In addition, a Dam Specific Safety Emergency Plan manages dam safety alerts and exercises are held regularly to ensure personnel are well trained for any emergencies.

In accordance with the NSW State Flood Plan, the NSW State Emergency Service is primarily responsible for the warning and evacuation of downstream communities in the event of a dam safety emergency. The State Emergency Service maintains a list of requirements for flood warning and flood gauges in NSW.

More information on State Emergency Service Flood Plans.

Contact details

Contact the WaterNSW Community Engagement Officer by phone on 1300 662 077 or email.


Thursday 09 July
2,077,049 ML
2,581,850 ML
8,809 ML
1,259 ML
-8,127 ML
Thursday 09 July