Don't swim: bay awash with wastewater

Hunter Water has advised that an overflow of wastewater occurred at the location overnight.

Workers have encouraged residents to avoid contact with the water in that area as a safety precaution.

That includes not swimming at the Swansea bay, not doing water activities in the area, and not fishing.

Crews are responding to fix the main as quickly and safely as they can, a Hunter Water spokesperson said on Thursday afternoon.

"It occurred as an intermittent leak through the night so it would have covered both tide directions," a spokesperson said, via a public social media post.

It's not yet known when the issue will be resolved.

It's set to be a scorcher at Lake Macquarie this Australia Day long weekend, with boaters expected to flock to the water.