The contamination of Raetihi township's water supply in the central North Island has also hit farmers using the scheme.
Farmers are having to find alternative sources of water for themselves and their stock after a major diesel spill from the Turoa skifield last week polluted a stream and forced the closure of the local reservoir.
Federated Farmers Ruapehu provincial president Lyn Neeson said livestock were refusing to drink from contaminated troughs, which meant farmers were having to move them to alternative water sources such as dams, or send them off the farm.
Between 10 and 20 farms were connected to the water supply, and they weren't aware it was contaminated until stock stopped drinking out of the troughs.
"There's also farms further south of Raetihi, where the river runs through, some of those farmers access the river for stock water so they've had to find alternative water sources. It's not so difficult for them, though," Ms Neeson said.
It could be the end of this week at the earliest before the council organised an alternative water supply, and then tanks and pipes would have to be flushed out, she said.
