A tsunami warning system will be operating along Christchurch's coast line from the beginning of July.
Work is under way to install 22 sirens from Waimairi Beach to Sumner.
Christchurch Mayor Bob Parker says a siren is more likely to be used if there was a tsunami sparked by a distant earthquake as a locally-generated tsunami is likely to be small, with a one- to two-metre wave, and there would be little time to react.
Mr Parker says local company Eaton Industries has contributed $120,000 towards the $500,000 cost of the sirens.
A series of community meetings will be held over the next month to inform people about how the sirens work.
