There were a spate of clear tests recently, however heavy rain from overnight on Wednesday until yesterday afternoon led to "exceedance across the board in the Ahuriri estuary", a Hawke's Bay Regional Council spokesman said yesterday.
Levels yesterday showed 770 Enterococci per 100ml, and 970 E.coli per 100ml - the no-swim red code limit is 550.
The source of the contamination has not yet been identified.
With the rain meaning more contaminants were likely to wash through the Ahuriri estuary/Pandora Pond system, a Hawke's Bay District Health Board spokeswoman said the warning would remain.
"We will continue to monitor and review."
The effects of the fortnight-long closure are being felt, with businesses losing money and parents fearful about the safety of the waterway.
At a time expected to be their busiest, businesses near the Pandora Splash Zone say they are losing money and customers, and are scared of the impact on future business.
Mr Jack said he only operated the store during summer, meaning this income helps through the rest of the year. He takes time off his second job over summer to run the kayak store.
"We're very sad, we've lost a lot of business," he said. "We've had no money to pay rent, power bills, anything. I can't believe it."
Nearby Hawke's Bay Bakery and Cafe owner Vandy Ban said his eatery was getting less and less business since the pond's closure.
"It's been very quiet, especially on the weekends. I'm losing money. We need the council to help me and fix [Pandora Pond]."
Even after the closure is lifted, Mr Jack said he was worried future customers might be scared away as they wouldn't be confident in the safety of the pond.
The spot's water quality is also of concern for Napier resident Ali Beal, who thought her daughter Georgia,became sick after sailing in Pandora Pond with her school on February 21, the day the warning was issued.
The 11-year-old suffered stomach cramps, nausea, and diarrhoea for nearly a week, and was unable to go back to school until Tuesday.
It's unclear what caused Georgia's sickness as test results came back negative for E. coli, however Ms Beal said she was "angry" Georgia and her classmates were exposed to contaminated water.
She has banned her daughter from swimming in the pond again, for fear nothing
was being done to improve the water quality.
"I'm really glad she's not got a dirty yucky disease, but what if she had?" she said.
"This is a really bad issue and it is going to continue. There's so many different things that go into that pond and that area. In my mind it's like you are going to keep getting sick people."
The Hawke's Bay District Health Board said since the warning was put in place there have been five self-referrals to Health Protection Officers from people feeling sick, but none were conclusively linked to the pond.
The DHB investigated one possible case of illness linked to Pandora Pond activity from before the warning was issued. This had been notified by a GP, but had since tested negative to common notifiable diseases.
DHB Medical Officer of Health Dr Nicholas Jones said they were taking all cases seriously, and wanted to hear from anyone who had swum in the pond, prior to the swim warning going up, and had experienced a gastro-like illness.
He said it was important to remember there are always gastro bugs circulating in any community, including viruses such as Rotavirus and Norovirus.
A Hawke's Bay Regional Council spokeswoman said it had received one online query about sickness. It had been taking five-litre samples daily since the initial contamination to try to identify the source.
The regional council and the Napier City Council,were working as hard as they could to identify the contamination, and on the future of the estuary area, she said, citing the Ahuriri Estuary Management Strategy, which seeks to ensure the long-term sustainability and health of the estuary and address a range of issues including water quality.
