Residents and visitors across the Cairns region are being asked to restrict their water use to drinking, cooking and bathing.
High turbidity in Freshwater Creek catchment caused by heavy rain has paused treatment operations, leaving the region dependent on water stored in reservoirs.
Cairns Regional Council has declared level 4 water restrictions to reduce drawdown from the reservoirs to extend the availability of potable water.
With heavy rainfall expected to continue over the coming days, it is unknown when treatment will recommence.
Council CEO Ken Gouldthorp said the combination of wet weather and reduced storage capacity presents ongoing challenges.
"We have been monitoring the weather events and the amount of water we've got stored in our reservoirs. Moving on restrictions now is a precautionary step to protect our water supply for the region," he said.
"The heavy rain has created high turbidity in our raw water supplies forcing our treatment operations to temporarily pause.
"With more wet weather predicted it is likely that water treatment plants may be offline for an extended period and we are implementing maximum water restrictions to extend water supply as long as possible.
"Level 4 water restrictions limits use to what's needed for people's health and hygiene. We are urging residents to stop watering gardens, washing vehicles or paved areas or filling pools for a period.
"The situation is evolving quickly, and we have teams working to ensure water supply is maintained and treatment operations recommence as soon as possible."
In addition to level 4 restrictions, the community can further help by limiting shower times and collecting rainwater for flushing toilets. Every extra bit of water saving counts.
Water restrictions will be reassessed once water treatment is reestablished, and supply is stabilised.
