WaterNSW continues releases from Warragamba dam

WaterNSW continues releases from Warragamba dam

02 September 2020

WaterNSW is continuing to make controlled, operational releases from Sydney’s largest supply dam after it filled and spilled just six-months after levels dropped below 45 percent.

With Warragamba now at 98.6% of storage capacity, the recent inflows have provided a major boost to Greater Sydney’s future water supply following a prolonged period of drought.

In line with operational guidelines WaterNSW has discharged more than 102 gigalitres (GL) of water from Warragamba since the initial spill event in mid-August, with the storage currently sitting 0.5 metres below Full Supply Level (FSL).

Levels in the dam will be progressively lowered to 1 metre below FSL creating 74GL of storage capacity and allowing for optimal conditions to operate dam infrastructure.

WaterNSW staff are closely monitoring the dam and catchment and, as always, working closely with the Bureau of Meteorology to watch for future rainfall.

Inflows into Warragamba continue at a rate under 2GL per day, while 3.5GL of water is being released daily through controlled discharges.

Small releases are made when the dam reaches 100% to avoid the main radial gates repeatedly opening and closing and to provide a small buffer for future rain events.

As Warragamba is the primary supply for the Great Sydney region and not a flood mitigation dam, its primarily objective is to capture and store the maximum volume of water for Greater Sydney.

There is an operational procedure (H14 operational protocol) for Warragamba dam, designed to manage inflows and spill events, so that dam releases are managed in a controlled manner. .

To release more water prior to a forecast rain event (and risk the water not being replaced if the rain did not eventuate) would be a breach of the key operational objective of the dam, to provide water security for Greater Sydney.

The SES is the combat agency in NSW and takes the lead in managing flood impacts.

Official warnings and flood advice are provided by The Bureau of Meteorology (the BoM) on their website and the NSW State Emergency Services (NSW SES) on radio stations and NSW SES social media.

The community are encouraged to understand the risk and obtain up to date information on preparing for floods by visiting: https://www.ses.nsw.gov.au/hawkesbury-nepean-floods/

More information on how WaterNSW operates Warragamba dam when it’s at or close to FSL can be found here.

Media contact – 0436 942 946 – Ben Ansell


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