WaterNSW successfully protects Sydney’s raw water

WaterNSW successfully protects Sydney’s raw water

18 February 2020

Precautionary measures enacted in the wake of unprecedented bushfire damage and the largest rainfall event since 1990 have been successful in protecting Sydney’s dam water quality, WaterNSW CEO David Harris confirmed today.

Warragamba Dam is resuming supply of raw water to the Prospect Water Filtration Plant after a considered decision was reached by WaterNSW experts earlier in the week to draw upon Prospect Reservoir as a precaution in case of water quality issues.

“Since December last year WaterNSW has been quite clear in saying that we wholly expected to encounter water quality challenges if large rainfall fell on bushfire-damaged parts of the Warragamba catchment, and were well-prepared with scientific expertise and operational contingency plans if that’s what eventuated,” Mr Harris said.

“We had a month’s supply in Prospect Reservoir available so we could draw on it until our expert monitoring team could fully understand the effects of the prolonged drought and extensive fire followed by heavy rainfall and confirm their confidence in the water quality in Warragamba.

“We spent the last week monitoring the intrusion into the Warragamba system and are now confident in resuming supplying raw water to Prospect Water Filtration Plant.

“Prospect Reservoir is regularly used to supply raw water to Prospect Water Filtration Plant. It’s a critical part of the system and it’s used quite often, when we take other parts of the supply system offline for planned maintenance.

“This is a standard part of operating Greater Sydney’s water supply network. Our experts regularly re-configure our network to deal with these issues and do so with minimal interruption to Sydney’s drinking water supply or quality.

“With safe raw water supply available from Prospect Reservoir, the people of Sydney would rightly have considered it irresponsible if we not taken every precaution with our decisions around raw water from Warragamba.”

During December and January, more than 320,000 hectares of the Warragamba Catchment was ravaged by fire. Since then, WaterNSW experts have been working to understand the potential consequences of the significant fire damage on water quality.

During and after the fires WaterNSW has consistently communicated its expectation that Lake Burragorang (Warragamba Dam) would be impacted with large amounts of debris when unprecedented amounts of bushfire ash coupled with a lack of ground cover to prevent soil erosion was washed into the water supply by heavy rains, most recently in a public statement on 14 February confirming water was not being taken from Warragamba Dam.

Monitoring continues by highly experienced water quality scientists using sophisticated, real-time technology pioneered by WaterNSW which can predict any change in the dam storage’s water quality.

Media contact: Ben Ansell 0436 942 946


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