On Wednesday, the Waitaki District Council issued a conserve water notice when users used 8500 cubic metres of water. Under the conserve water notice, water use spiked to 10,500 cubic metres yesterday.
Council assets group manager Neil Jorgensen said the matter was urgent.
"The message isn't getting through, and if we carry on at that rate, we've got about two days of water left. And then we'd have to start delivering untreated water, which means everyone would have to boil their water, including businesses, cafes . . .'' he said.
"It's quite serious.''
The conserve water notice was in effect in Oamaru, Weston, Hampden, Herbert and Enfield, and south to Moeraki.
The council believed four days of essential use only would "get us through'' -- it asked that people on the Oamaru supply do no clothes washing; no car cleaning; "no water use at all that is not absolutely necessary"; do not use dishwashers; do not water plants; and limit the amount they flush the toilet.
Last week's rain caused the water entering the Oamaru treatment plan to be three times dirtier than it had ever been in the past, Mr Jorgensen said.
The turbidity entering the supply had now dropped, but during the rain storm, it was the most turbid the council had dealt with.
The most turbid water the council had ever dealt with in the past was 50 nephelometric turbidity unit (ntu), during the rain it eclipsed 150ntu.
Mr Jorgensen said he could only speculate as to the cause of the dirty water at this stage, but the council would investigate.
In a statement today, the council said further to the conserve water notice, water supply to the following areas were turned off last night: Kakanui township and surrounds; Herbert area, including Waianakarua; Hampden township and surrounding area and the booster pump supplying Moeraki and surrounding area.
