UNPRECEDENTED emergency water restrictions have been placed on Sunraysia residents as the region prepares for a heatwave in coming days.
Extremely poor source water quality in the Murray River has forced Lower Murray Water to restrict Mildura, Merbein and Irymple residents from external use of town drinking water.
Lower Murray Water's technical officer Luke Marcombe confirmed both Mildura treatment plants had been "significantly impacted" by the blue-green algae outbreak.
"This has never happened before," he said.
"With the algae outbreak we've had in the river, it's now coming through the plant and creating sludge like we've never seen or had before."
External restrictions will stay in place until further notice, but Lower Murray Water assured water quality is safe for all internal and domestic purposes.
Mr Marcombe said restrictions were imposed "now" in order to better maintain storage levels during the unprecedented forecast temperatures this week.
"Unfortunately the temperature lining up with the poor river quality is a double whammy, it makes it hard because consumption increases," he said.
"If we don't catch up now, there's risk we won't be able to cope.
Red Cliffs residents were late on Sunday on advised to boil town water before drinking it as part of emergency use restrictions.
The boil water notice was on Monday removed but emergency use restrictions remained in place until further notice.
Lower Murray Water managing director Anthony Couroupis told Sunraysia residents there was "no compromising" water quality and said community support was "critical".
"What we're keen to do is make sure we don't compromise quality and or critical human needs," he said.
"We just can't keep up with the quantity.
"The risk is if we run our systems into the ground, we can't supply local residents ... we run out of water and we compromise quality."
Mr Marcombe and Mr Couroupis hoped residents would turn off their sprinklers while crews worked "around the clock" to improve the situation.
"Pretty much anything you would use water for outside the house is what we're asking people not to use," Mr Marcombe said.
Further information can be found on the LMW website www.lmw.vic.gov.au or by calling 03 5051 3400.