Lake Wallace's blue green algae alert has now been downgraded to an amber alert.
Lithgow City Council updated the warning this week, but warned people should still be cautious as the water may be unsuitable for stock watering. An amber alert indicates that the water may have a green tinge and musty or organic taste and odour.
The water remains suitable for recreational use, however conditions may change depending on algal concentrations. Users are urged to avoid the water if there are any signs of blue-green algae.
Sampling of the lake will continue.