WaterNSW responds to ABC TV report (Sunday, 1 December) concerning water quality at Cataract and Cordeaux dams

WaterNSW responds to ABC TV report (Sunday, 1 December) concerning water quality at Cataract and Cordeaux dams

02 December 2019

By not incorporating important information made available by WaterNSW, last night's ABC report failed to portray the safeguards and expertise that protect Sydney's drinking water quality at its source.

WaterNSW manages water quality in all Sydney's drinking water catchments to ensure raw water is treatable to strict Australian Drinking Water Guidelines.

Iron levels in untreated water supplied to treatment plants have not exceeded the levels stipulated for treatment.

WaterNSW can select water from various dams and from various depths within dam storages, to ensure the optimal quality of water is supplied for treatment.

The levels of iron and aluminium in the water supplied from Cataract, Cordeaux and Avon storages are not at a level that would cause WaterNSW concern and supplies continue to meet treatment plant specifications.

Importantly, deep water monitoring results referenced by the ABC are taken below the level from which water is released, and are therefore not indicative of the water supplied for treatment.

It is normal to see elevated levels of iron (and other metals) close to the sediment layer in a storage, due to naturally occurring low levels of dissolved oxygen. It is misleading for the ABC to infer that this water is being supplied to treatment plants.

In any dam storage water quality is not homogenous and the water at the bottom is typically the poorest quality, due to factors such as inflows, catchment size and condition, storage dynamics, and surrounding geology.

The NSW Government has recently received the final report from the Independent Expert Panel on Mining in the Catchment.

Amongst its findings, the report concluded there is no evidence that mining in the Special Areas is currently compromising the ability of WaterNSW to meet raw water supply agreement standards.

The NSW Government and WaterNSW are currently reviewing the report and will respond in due course. In the interim, the government has announced that no new development applications for mining in the Special Areas will be determined.

Media Contact – Tony Webber – 0428 613 478


Monday 18 October
2,426,169 ML
2,581,850 ML
9,030 ML
1,290 ML
3,065 ML
Monday 18 October