Resident Lina Bausch, who first noticed the odour on Friday, said the smell made her nauseous. 

“Like a swimming pool,” she said when asked to describe the smell that not even her carbon filter was able to remove.

“It's always been yucky, but not like this.” 

Others reported their drinking water was coloured brown. 

Neighbour Suzanne Round this week bought bottled water for drinking and topping up her fish tank, worried the tap water would do harm to her pets. 

She was not alone; the town’s IGA supermarket said it had seen above-average sales of bottled water since the complaints began.  

The expense would be a burden for families larger than her own, Ms Round said.  

But a Coliban Water spokeswoman reassured residents their tap water was safe for drinking, bathing and food preparation.

While chlorine was used as part of the treatment process, levels met the Australian Drinking Water Guidelines, she said. 

The ADWG outlines between 0.2 and 0.5 milligrams of residual chlorine per litre as an “adequate” level to protect the distribution system against re-contamination. 

Brown-coloured water could also be the result of changing water quality in Lake Eppalock, from which Heathcote’s raw water is sourced. 

“Our network crews are responding to complaints with targeted flushing of the  water mains,” the spokeswoman said.

“We are continuing to monitor the raw water supply to make sure our treatment processes are appropriate.”

Water quality complaints are nothing new for Heathcote. Ms Round said she boiled her water for 17 years, while Ms Bausch was saving to install a water tank.

“But I’m a pensioner, and I can’t put in a tank overnight,” Ms Bausch said.

Those whose water changes odour and colour should run their taps until it clears. If the problem persists, phone Coliban Water on 1300 363 200.