One year on from a gastric illness outbreak in Havelock North because of contaminated water, a candlelight vigil will be held around New Zealand.

Havelock North, Wellington, Christchurch and Dunedin will co-host a twilight "Vigil for Water" on Sunday.

Organisers said the aim is to send a message to central government and local authorities that communities and the environment need clean water.

About 5500 people were struck down with campylobacter last August because of contamination of the Havelock North water supply. The outbreak was also linked to three deaths.

Havelock North vigil organiser Michaela Evans said the event in the Hawke's Bay town is to acknowledge the effect that polluted water has had, and to show that people care and want to be heard.

"We will keep speaking up until we see changes in place all over the country that would prevent such an event from happening again," she said.
Annabeth Cohen, from Forest and Bird and who will speak at the Christchurch vigil, said New Zealand's waterways were in crisis.

"They used to be full of native fish, eels, river birds, and insects," she said.

"Now our rivers and lakes are awash with cow effluent, sediment and algae, and they dry up in summer."