The odorous spill that seeped excrement into streets and parks in Perth's south started on Friday.
"The smell was terrible, putrid, disgusting," a resident living across the street from one of the spills told AAP on Tuesday.
"It was massive and went right across the oval like a pond, but it was sewage and I could smell it right through the house."
The woman, who asked not to be named, said she was concerned about the impact on the health and wellbeing of residents.
"There are a lot of children who play around here and people who like to get out and walk their dogs," she said.
The foul flow near the woman's home gushed from a broken pipe at the top of a small hill down a residential street lined with houses into the soccer oval.
A worker manning a roadblock in the area said a "river of shit" had flowed down the road into the oval, creating "a swimming pool of sewage".
Joslyn Reece said the "powerful and foul" smell from the leak was at its worst at night and had woken her on several occasions.
"I feel like I'm smelling disease. I think I brushed my teeth 20 times last night," she said with a laugh.
The sewage leaks at five locations in various suburbs have been stopped, but not before waste flowed into the Swan River at multiple points and Fremantle Harbour near a sailing boat club.
Residents have been told not to exercise outdoors if there is a strong odour.
People have also been warned against water recreational activities including fishing and crabbing in the river and harbour near the outflow points
"If you feel unwell and experience symptoms such as headaches, fatigue and nausea, seek medical advice," the Western Australian water authority said.
Pipe repairs are expected to take "some time to ensure the safety of crews" in the impacted suburbs of Spearwood, Beaconsfield, Alfred Cove, Applecross and South Fremantle.
"Given the complexity of the wastewater network and the amount of wastewater backed up in the system, there remains a risk of further localised overflows," the authority warned.
There are also concerns forecast rain could lead to the pollution spreading.
Opposition water spokesman Peter Rundle said it was unacceptable raw sewage had spilled into the Swan River and suburban streets.
"This isn't just an infrastructure failure; it's a serious public health and environmental risk that's left families and communities exposed to human waste," he said.
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