Heavy rain and flooding have prompted "boil-water" notices for half of the Central Otago district's town water supplies, and has also caused problems in South Otago.
Patearoa, Ranfurly, Omakau, Naseby and Lake Roxburgh residents are being told to boil their water before drinking it, after heavy rain last weekend discoloured water supply sources.
Central Otago District Council water services manager Russell Bond said dirty water was the problem in all cases.
"There was a significant amount of rain, especially on Saturday night, and that's affected the sources of those supplies."
Patearoa's water comes from the Sowburn, Ranfurly and Naseby water comes from the Eweburn, Omakau's supply is from the Manuherikia River and Lake Roxburgh's water is from the Clutha River.
The Manuherikia River was in flood at the weekend but there were no concerns about the Clutha. However, floodwaters from the Manuherikia have now discoloured the Clutha at Alexandra, causing the problems with the Lake Roxburgh water supply.
Mr Bond said although the Patearoa supply was expected to clear in the next day or so, followed by Ranfurly, the rest of the boil-water notices could apply for several more days.
These were the sort of events the council was required to deal with more effectively under the revised Ministry of Health standards for drinking water, he said.
Clutha District Council contractors were called to a major leak on the Glenkenich rural water scheme near Pukerau yesterday.
The council is advising users of the Waikoikoi and Pukerau township areas of the Glenkenich Rural Water Scheme to conserve water as the scheme will take a few days to recover.
