Water sampling clears Blowering Dam for public reopening

Water samples collected after a dark bloom was detected on Jounama Dam on Thursday, prompting the snap closure on Friday morning, were sent to Sydney for urgent testing over the weekend.

The biological matter detected on the lake has been identified as a non-pathogenic protozoan not known to pose a risk to human health, WaterNSW said as it announced the dam's reopening on Monday afternoon.

"While the presence of this type of microscopic organism can sometimes indicate a potential risk to human health, such as a blue-green algal bloom, the results from the water sampling show no toxic cyanobacteria or associated toxins present," it said.

"With these results, and following consultation with NSW Health, WaterNSW is re-opening all recreational areas in the dam, including boat ramps and access to the dam wall.

"WaterNSW will continue to closely monitor water quality at Blowering Dam to ensure the water remains safe for recreational use."

The organisaton was criticised for its handling of the closure, both in terms of transparency and communications, with many users unaware of the situation until they arrived at the dam.

Snowy Valleys mayor Ian Chaffey told The Daily Advertiser it only came to his attention when a constituent contacted him about the situation late on Friday night, seeking further information, and was disappointed with the lack of information provided.

State MP Joe McGirr has also taken his concerns around the messaging to the state water minister.

"Public safety is the absolute priority and I fully understand that the closure is necessary to allow for testing for a potential water quality issue, but I am concerned that this news was not conveyed more widely to the community when the decision was taken," he said.

WaterNSW has since apologised for the inconvenience.

"The decision [was made] to temporarily close the dam and recreational areas as a precautionary measure to protect the community, and prioritise public health and safety, while water quality investigations were underway," WaterNSW said.

"Blowering Dam is a popular recreational area and WaterNSW apologises for the inconvenience of closing the dam at short notice."