After Cyclone Gita hit the Maniototo with high rainfall in mid-February, the town's water supply was declared unsafe to drink. The notice was put in place on February 23.
Fantail Kitchen & Larder owner Kerry Tackney-Scott said the lack of information was the "hardest part".
"We've had no information on it, no real updates from anyone."
"Workers come in here and mention it ... but the council could come and notify people."
Ranfurly Holiday Park and Motels owners Paul and Amanda O'Connell said while they were coping without water, communication from the council had been scarce.
"The last update was on the 8th [March]. It wouldn't take much just to keep changing the website so they're still thinking about us" Mr O'Connell said.
They were sending customers to Maniototo Area School to draw drinking water from a tanker there and advising people to buy bottled water.
However, Mrs O'Connell said it would be difficult to get adequate drinking water for large groups.
Next week, a group of about 50 from an Alexandra school were due to stay at the park.
The couple had lived in Ranfurly for five years and said it was the first time they had encountered a boil water notice in the town.
But they were still keeping positive.
"It's a good excuse to drink beer," Mrs O'Connell quipped.
Central Otago District Council executive manager infrastructure services Julie Muir said it would be Monday at the earliest before the notice could be lifted.
The turbidity levels of the water source, the East Eweburn, had dropped enough by yesterday morning to test for water quality. The first sample was taken but had to be sent to Auckland for analysis.
"There needs to be three days of clear testing before the boil water notice can be lifted," she said.
Water tankers are stationed at the Maniototo Area School and Maniototo Hospital.
District councillor Stuart Duncan said rain in the high country caused the town's water supply to become discoloured.
"The colour's got to settle. In the old days you could turn it on and away you go but it's different after Havelock North [in 2016]." When the North Island town's water supply became polluted, one-third of the residents fell ill and three elderly people died.
Ms Muir said there was $600,000 in the council's draft 2018 Long Term Plan to upgrade the Ranfurly water treatment plant and the council had engaged a consultant to begin design work.
Another $300,000 was set aside to upgrade the Patearoa treatment plant.
The upgrades were scheduled to happen in 2020-21.
Ms Muir said planning for the Omakau and Naseby treatment plant upgrades was also progressing.
