Havelock North is struggling to maintain normality as a quarter of the town's population is struck down with camplyobacter.

Half of all households are affected by the country's largest water contamination emergency.

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Hastings mayor Lawrence Yule has met owners of cafes and restaurants who have shut their doors during the crisis.

He said the outbreak has starting to have real economic impacts as well.

"There are now major business interruption issues starting to develop. As people become well again and as schools start to be re-populated, we need to make sure that the Havelock North community actually gets up and running as soon as sensibly possible."

Black Barn Vineyard and Luxury Retreat in Havelock North is losing bookings because of the water crisis.

Black Barn spokesman Francis de Jager said some clients from out of town aren't willing to take the risk, and have postponed.

He said luckily, one couple booked for this weekend won't let campylobacter ruin their big day.

"There's a wedding and the whole party is staying with us as well. They were very concerned about what the issues may be or the risks. Luckily, they decided to continue with the wedding. Some other retreat guests have decided to put off their stay until another time."

But getting up and running won't happen now for some time, as all primary and intermediate schools will remain closed until Monday.

Schools closed until next week include Havelock North Primary, Te Mata Primary, Lucknow Primary, Havelock North Intermediate and Hereworth School.

However, secondary schools including Havelock North High School, Iona College and Woodford House will reopen today.

Community and public meetings will be held for residents in Havelock North next week.

Lawrence Yule is promising to front the community on the outbreak, but can't confirm just yet when the meetings will be held.

"That is a fine balance between people still being unwell versus when we do that, but as soon as when it practically makes sense to do."

A retired High Court Judge is likely to lead the investigation into how the town's water supply became infected.

Acting Health Minister Sam Lotu-Liga said the Ministry will work alongside the Hastings District Council in that investigation.

"We need a level of independence, the belief there is there will be a retired High Court judge, but we're working through those terms of reference at the moment."