Both businesses and people's health would have benefited from a lockdown in Havelock North when campylobacter was found in its water supply, says an Auckland academic.

"Stopping the movement of people and trying to find the source of the problem should have been key priorities," says Bridgette Sullivan-Taylor, a senior lecturer in Management and International Business at the University of Auckland Business School.

"That could have contained the spread of the illness, which has now affected over 4100 people and more than half the town's households at the latest estimate, and possibly been a factor in one woman's death.

"A lockdown would have also given clarity to business owners that they could claim insurance for disruption to business due to forced closure. Business continuity management aids a quick economic recovery."


Dr Sullivan-Taylor queried the government's refusal to officially declare a water emergency.

"There is a shortage of uncontaminated water and a lack of confidence in water security so I would say that there is a water emergency.

"Water security in general should be a major concern for governments, in case of chemical or biological attacks or this sort of thing. Water is an example of critical national infrastructure."

New Zealand was well prepared for earthquakes but public-private partnerships should develop contingency plans for a range of emergencies and rehearse responses.

"The council and the DHB should have had a broad emergency preparedness plan in place. The plan should involve all stakeholders in the community and private sector partners such as local business associations, and they should have rehearsed for scenarios such as this. Especially after contamination of one of their water bores in 2015.

"The number one priority should be to stop spread of infection, the second to keep amenities functioning. It's about the benefit of foresight."

She said a plan should include:

- A common co-ordinated communication strategy with multiple channels.

- Supply chain planning - food, clean water, bedding and other supplies to be brought under different scenarios.

- Arrangements to bring in reinforcement workers, for example, extra doctors

- Businesses work with local authorities to clarify insurance and compensation implications

- Schools and other public facilities receive clear guidance when to close or restrict movement of people and stock.

Dr Sullivan-Taylor began researching business, organisational and community resilience in Great Britain and advised officials during the review of the United Kingdom's national security and Civil Contingencies Act in the early 2000s.

Hastings Mayor Lawrence Yule said a major advertising campaign will be launched to bolster the Havelock North brand and attract people, once the water was cleared.

A UV treatment plant is expected to be in place by Friday, providing an additional level of treatment on top of chlorination and should enable the boil-water notice to be removed, a major hurdle for food-service businesses.