There is disappointment from Dunedin businesses over the city council's handling of the water crisis.

More than two-and-a-half thousand properties in central and North Dunedin will remain on a boil water notice until Friday at the earliest.

It's after millions of litres of untreated "raw" water from the Ross Creek Reservoir entered the drinking supply.

The boil water notice is still in effect for North Dunedin, the CBD and Leith Valley today. Get info and advice here https://t.co/csGF8lye45

— Dunedin City Council (@DnCityCouncil) August 15, 2017

Dunedin City Council started informing residents and businesses yesterday morning.

But Otago Chamber of Commerce chief executive Dougal McGowan said some businesses were left in the dark.

"Some didn't know about it until reasonably late in the afternoon so they had to throw a whole lot of stuff out," he told Newstalk ZB.

Not all businesses have been affected though, with some even using their Kiwi ingenuity to get around the crisis.

A No. 8 wire approach at Nova helped locals get their caffeine fix this morning, according to head chef Evan Young.

"We've just got a big sixty litre pot of water. Got the plumbing straight into that and it's just sucking the water out of that. Coffee's all go. That's all it takes."

Foodstuffs, meanwhile, has had to destroy all products made in the last 24 hours.

Residents are still advised not to drink tap water, and the council has provided free bottled water.